Tire life cannot be predicted. Its size is directly dependent on several factors in the complex: design, pace and level of driving, climate, condition of road surfaces, care. The current condition of tires is directly dependent on the mileage of the car and is one of the first rows of the rating for safe traffic on the roads.

To ensure it, strict observance of the rules for operating the vehicle, tireless monitoring of the condition of tires and their degree of wear are necessary. It is unacceptable to use a car when the residual height of the tire tread is lower than the minimum allowable level. How to determine tire wear? What are its signs? It will be about this.

Types of tire wear, causes

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The tread is the only component of the tire that has direct contact with the road. The main technical indicators when coupling the machine with pavement are quality rubber tread depth.

The allowable wear standard is 0.16 cm over the entire tread area in summer, 0.4 cm in winter.

No. p / p	Violations in operation	Type of wear	Causes
1	Overloading of tires due to non-compliance with the norms of internal air pressure.	Double-sided, along the perimeter of the wheel.	Tire pressure too low.
2	Lack of systematic tire maintenance and repair.	In the middle around the perimeter.	The tire pressure is too high.
3	Mounting and dismantling of tires is carried out with violations of the PTE. According to the rating, it occupies a leading position.	The front wheels are subject to wear on the outside.	Wheel alignment angles incorrectly adjusted High speed on a curved road (rating goes off scale). Flipping tires on rims or swapping front and rear wheels helps prevent continued wear. When tires are abraded along the outer edge more than in the center, it indicates that the machine has been used for a long time at a low level of tire pressure.
4	Wheel imbalance	The side parts of the working surface are subject to partial abrasion.	Violated static and dynamic wheel balancing. Excessive runout of the disc from the side, increased play in wheel bearings or suspension arms is not excluded.
5	Violation of the working condition of the running gear with the steering of the car.	The working surface of the tire is partially abraded in the center.	There is no static wheel balancing. There may be excessive rim runout.
6	Accompanying overloads or underpressure up to 10% can reduce mileage by 20%. When choosing tires according to the given rating parameters, one should adhere to the indicators characterizing the maximum load. A margin of 10-15 percent will keep the rubber even with partial overload.	Significant degree of wear.	The result of wheel lock during emergency braking. Or blocking is accompanied by an unchanged position of the oval brake drum.
7	Gravel and gravel on the road surface provoke the formation of rubber damage.	Wear of the scaly or serrated format as a result of carcass breaks.	Exceeding the maximum possible load; inspection of the inside of the tire is necessary to detect cracking.
8	Systematic movement in high-speed mode. The emerging thermal energy, as a result of internal friction, leads to heating of the rubber coating. Unfavorable temperatures of the outer and inner parts destroy the tread surface, leading to delamination between the connecting parts of the tire. A temperature of 120 degrees reduces the strength of rubber by forty percent.	Sharp edges on the front wheels.	The result of frequent and high-speed driving on "broken" roads, cornering.
9	A sporty driving format with frequent and harsh acceleration and deceleration leads to increased wear. This situation is based on tread slippage in the contact patch. Long-term emergency braking at high speeds provokes the creation of wear spots, not excluding the separation of the tread elements.	Rupture of the frame.	High-speed driving in extreme mode on a dangerous surface (the leading position in the rating is sharp stones, rail joints, etc.).

Tire protector. Definition of wear

You can track the degree of wear of car tires using:

• wear indicator,
• profile depth markings,
• tire color changes.

The wear indicator is a system familiar to all motorists, which occupies one of the first places in the ranking. The indicator, otherwise the tread block (1.6 mm) is in the longitudinal grooves. The connection of the groove and tread levels indicates the end of the tire's life and must be replaced. Otherwise, it is considered as an offense.

As a classic method of determining, marks are fixed on the side of the tire:

• TWI markings;
• marker logo;
• triangle indicator.

Some manufacturers practice the use of intermediate indicators, the disappearance of which on the rubber surface indicates the danger of use on slippery surfaces.

The operation of the digital wear indicator is based on the application of digital symbols on tire treads. The numbers corresponding to the depth of the grooves are subjected to abrasion in accordance with the level of wear achieved. This method of determining tire wear is used by rating companies Nokian and Matador.

Profile depth gauge. Offered in a small device format. It can be purchased at a specialized auto center at the best price. Endowed with the functionality of measuring the depth of the tread grooves. If wear indicators are a quick way to determine wear, then a tire profile depth gauge is a highly accurate prediction.

Determining tire wear is a very important process on which driver comfort and safety depend. You should always monitor the condition of your car and be able to determine the condition of the tires in time.

Ministry of Education and Science of the Russian Federation

Volgograd State Technical University

(VolgGTU)

Department "TERA"

Special course of technical operation of cars

Course work

"Features of the operation of car tires"

Completed:

student gr. AE-513

Soldatov P.V.

Checked:

Assoc. cafe TERA

Boyko G.V.

Volgograd 2011

Introduction

1) The device of car tires

1.1) Tire marking

1.2) The design of the wheels of passenger cars

1.3) Tire specifications

1.4) Interaction of tires with the road

2) Features of the operation of car tires

2.1) Tire rolling energy loss

2.2) Tire grip

2.3) Cushioning properties of tires

2.4) Durability, wear resistance, tire imbalance

2.5) Types of tire wear

2.6) Tire inflation pressure and tire overload

2.7) Influence of driving style on tire wear

2.8) Irregular tire maintenance and repair

2.9) Violation of the rules for mounting and dismounting tires

2.10) Wheel imbalance

2.11) Proper selection and fitting of vehicles with tires

2.12) Repair of tires in a car company

3) Features of the operation of winter tires on trucks

3.1) Winter non-studded tires

3.2) Winter studded tires

Conclusion

List of sources

Introduction

When carrying out road transport, a considerable part of attention should be paid to traffic safety. Car tires as structural elements of the car, directly in contact with the road surface, have a significant impact on the stability, handling and braking performance of the car. And they, in turn, ensure not only the safety of life and health of road users, but also the safety of the transported cargo. Do not forget about the fuel and economic characteristics of the car, which also depend on the rolling resistance of tires. The characteristics of car tires also affect the noise level from a moving car. These and other important factors associated with the operation of tires will be discussed in detail in this paper.

1 Tire device

1.1 Tire marking

Car tires are marked with an alphanumeric code, which is indicated on the side of the tire. This code defines the dimensions of the tire and some of its key features, such as load and speed indicators. Sometimes the inner bead of a tire contains information not included in the outer bead, and vice versa.

Tire marking has become much more complicated in recent years, modern tires are marked with traction, tread, temperature resistance, and other indicators.

Rice. 1 - tire marking

1 - Model (name) of the tire; 2 - Vehicle code; 3 - Tire width in millimeters from bead to bead; 4 - The ratio of the bead height to the full width of the tire in percent; 5 - R cord direction; 6 - landing diameter; 7 - Load index and speed sign 8 - US DOT identification number; 9 - type of road surface; 10 - Cord material and rubber composition; 11 - Manufacturer; 12 - Maximum load index; 13 - Code of traction, protector, temperature resistance; 14 - Maximum tire pressure;

Additional tire marking

M*S: On winter tyres, the above marking may end with an "E" for studded tires.

E4 - Tire certified according to ECE regulations (the number indicates the country of approval).

030908 - tire certification code

DOT code: All tires imported into the US have a DOT code as required by the Department of Transportation, this code identifies the company and factory, soil, batch, and production date (2 digits for the week of the year plus 2 digits for the year; or 2 digits for the week year plus 1 digit for the year for tires made before 2000)

TL - Tubeless

TT - Tubetype, tube tire

Made in - Country of origin

C (commercial) - Light truck tire (Example: 185 R14 C)

B - Motorcycle tires (Example: 150/70 B 17 69 H = diagonal design with belt under the tread

SFI - abbr. for "side facing inwards" = inward asymmetrical tires

SFO - abbr. for "side facing outwards" = outward asymmetrical tires

TWI - Tire wear index, tire profile indicator that shows when a tire has worn out and needs to be replaced

SL - (standard load = standard load): Tire for normal use and load

Rf - Reinforced tires

Arrows - Some types of tire tread are designed to give the best effect when the tire is rotated in a certain direction (clockwise or counterclockwise). Such tires will have an arrow showing which way the tire should rotate when put on the vehicle's wheel. For adequate dynamic behavior of tires, it is important to follow this instruction.

Fig. 2 - Additional marking of car tires

A yellow dot (circular or triangular mark) on the sidewall indicates the lightest spot on the tire. When installing a new tire on a rim, the yellow mark must be aligned with the heaviest spot on the rim. This is usually where the nipple is attached. This allows you to improve the balance of the wheel and put weights of less weight.

On tires with mileage, the marks are no longer so relevant, since, as a rule, when the tire wears, its balance shifts.

Red dot - means the place of maximum power inhomogeneity, the manifestation of which is usually associated with various connections of different layers of the tire during its manufacture. These irregularities are completely normal and all tires have them. But usually only those tires that go to the primary equipment of cars are marked with red dots, i.e. when the car leaves the factory.

This red mark is combined with white marks on the rims (white marks on the rims are also placed mainly for the original configuration of the car), which indicate the closest place to the center of the wheel. This is done so that the maximum inhomogeneity in the tire is minimally affected when driving, providing a more balanced power characteristic of the wheel. During normal tire fitting, it is not recommended to pay attention to the red mark, but to be guided by the yellow mark, combining it with the nipple.

The white stamp with a number indicates the number of the inspector who carried out the final inspection of the tire at the manufacturing plant.

Colored stripes on the tire tread are made to make it easier to "identify" the tire in stock. For all models and different sizes, these strips are different. Therefore, when tires are stacked in warehouses, it is immediately clear that a given stack of tires has the same size and model. These colored stripes on the tire have no other semantic load.

1.2 The design of the wheels of passenger cars

The wheel is an integral part of the car, so its design must be closely coordinated with the design of the chassis of the car and meet the requirements that are dictated by the conditions of its operation. In this regard, wheels of various designs and sizes are used for cars, trucks, specialized vehicles and buses. It is customary to subdivide wheels according to their belonging to one or another type of rolling stock, according to the type of tires used, the design of the disk and rim, and the wheel manufacturing technology.

Any wheel, as a rule, consists of two main parts: disc 1 with rim 2 (Fig. 3) and tires. According to the type of vehicle, the wheels are divided into three groups: for passenger cars, for trucks, including buses, and for special-purpose vehicles.

Rice. 3 - Wheel of a car GAZ-24 "Volga"

a - wheel design; b and c - profiles of landing shelves for tubeless tires; d - symmetrical rim profile; 1 - stiffeners; 2 - rim; 3 - disk; 4 - profiled part of the disk.

For passenger cars, wheels with deep one-piece rims are mainly used (see Fig. 3). The disc is attached to the rim by welding or less often by rivets. To ensure strength, the disc is given a special configuration that increases its rigidity. Rims for passenger car wheels are mainly made with inclined (conical) flanges. The slope of the shelves is assumed to be 5°.

For passenger cars, wheels with a diameter of 15, 14 and 13 inches with a rim profile width of 4 ... 7 inches are most widely used. The wheel rims of passenger cars have a complex configuration and are made by stamping from a sheet, which gives it the necessary rigidity.

Wheels are usually denoted by the main dimensions (in inches or millimeters) of the rim, namely: the width and diameter of the landing shelves. After the first digit or group of digits, a letter of the Latin or Russian alphabet is placed, characterizing the set of dimensions that determine the profile - the side flange of the rim (A, B, etc.).

1.3 Tire specifications

Tires are characterized by purpose, sealing method, type, design and tread pattern. As mentioned earlier, depending on the purpose, tires for cars and trucks are distinguished. Passenger car tires (Table 1.2) are used on cars, light trucks, minibuses and trailers for them. According to the method of sealing tires are divided into chamber and tubeless. According to the design (according to the construction of the frame), diagonal and radial tires are distinguished (Fig. 4). According to the configuration of the cross-sectional profile (depending on the ratio of the height of the profile to its width) - ordinary profile tires, wide-, low- and ultra-low profile.

Rice. 4 - Tires of diagonal (a) and radial (b) designs:

1 - protector; 2 - layers of the breaker; 3 - carcass layers; 4 - rubber layer of the frame; 5 - side part.

Depending on the operational purpose, car tires have the following types of road tread patterns (Fig. 5):

Rice. 5 - Types of tread pattern:

a - road; b - directed; c - increased cross-country ability; g - career; d - winter; e - universal.

Road pattern (Fig. 5, a) - checkers or ribs dissected by grooves. Tires with a road tread pattern are designed for use primarily on roads with improved coverage;

directional pattern (Fig. 5, b) - asymmetrical with respect to the radial plane of the wheel. A tire with a directional pattern is used for operation in off-road conditions and on soft soils;

Cross-country tread pattern (Fig. 5, c) - high lugs separated by grooves. Tires with this tread pattern are used for off-road use and on soft soils;

Quarry pattern (Fig. 5, d) - massive protrusions of various configurations, separated by grooves;

The winter tread pattern (Fig. 5, e) is a pattern where the protrusions have sharp edges. Tires with this pattern are designed for operation on snowy and icy roads and can be equipped with anti-skid studs;

Universal pattern (Fig. 5, f), checkers or ribs in the central zone of the treadmill and lugs along its edges. Tires with this tread pattern are designed for use on roads with improved lightweight coverage.

Classification of tires by purpose is important, as it determines the basic requirements for the design of the tire.

A tube tire has a complex configuration and consists of many structural elements: a carcass, a belt, a tread, a sidewall, beads, and a tube with a profile height to width ratio of more than 0.80. For diagonal tires, the carcass and breaker cord threads intersect in adjacent layers, and the angle of inclination of the threads in the middle of the treadmill in the carcass and breaker is 45 ... 60 °.

A tubeless tire looks almost identical to a standard car tire in appearance (Fig. 6). The difference from standard tires is the sealing 1 (airtight) layer on the inner surface of the tire and the sealing layer 2 on the outer surface of the beads.

Tubeless tires have a slightly smaller fit diameter relative to the fit diameter of the rim, a special bead shape and design that provides a tighter fit of the tire on the wheel rim in the presence of air pressure inside the tire. Abroad, tubeless tires are produced with a self-sealing inner layer and radial ribs on the sidewalls to cool the tire.

Rice. 6 - car tire device

1 - frame; 2 - layers of the breaker.

The cord for tubeless tires is made mainly from viscose, nylon and nylon. Weight-measuring tires have sealed rims. Valve 3 with sealing rubber washers is attached directly to the wheel rim. A feature of tubeless tires is that their carcass is constantly under the action of compressed air, which leaks during operation: through the sealing layer of the tire. In these cases, the air in the tire carcass creates tension between the individual elements of the tire and causes delamination. Therefore, in order to eliminate this harmful phenomenon, tubeless tires are provided with special drainage holes through which air penetrating into. frame is retracted outside.

The main advantage of tubeless tires is the increased safety of the car at high speeds compared to tube tires. A tubeless tire consists of one solid part, so the air from the cavity can only escape through the puncture hole, and the internal pressure is reduced slowly, so that the driver can drive with a damaged tire to the repair site. It should be noted the best heat removal directly through the metal rim of a tubeless tire, the absence of friction between the tire and the tube and, as a result, a lower temperature regime of the operating tire.

Tubeless tires are also characterized by greater stability of the internal air pressure, which is explained by the fact that air seeps through the unstretched airtight layer of a tubeless tire with greater difficulty than through the expanded walls of the tube. Tubeless tires are less dismantled and mounted during operation, since minor damage can be repaired without removing the tires from the rim.

Tubeless tires, interchangeable with tubed tires, can be mounted on standard deep rims if they are sealed, that is, they do not have dents or damage.

The warranty mileage standards for tubeless tires are the same as for tube tires, however, the experience of operating tubeless tires shows that their durability is 20% higher than that of tube tires, which is explained by the better temperature regime of tires and the constancy of internal air pressure in them. However, their production requires high-quality materials, but they are less technologically advanced. The operation of tubeless tires requires a high technical culture.

Radial tires with metal cord are produced in three types: with metal cord in the carcass and breaker, with nylon cord in the carcass and metal cord in the breaker, with a meridional arrangement of steel or nylon cord threads in the carcass and metal cord in the breaker (Fig. 6).

Steel cord tires have a wider bead opening than conventional tires. The ends of the layers' cord are wrapped in pairs around one or two bead rings wound from the same wire. On the inner side of the carcass in the area of ​​the treadmill, steel cord tires have a vulcanized rubber layer. It serves to protect the tube from punctures and more evenly distribute stresses in the body of the tire and in the area of ​​the treadmill.

Metal cord, having high thermal conductivity and heat resistance, helps to reduce stress and more uniform temperature distribution in the body of the tire. The service life of tires with steel cord is approximately 2 times longer when operating in various road conditions than that of conventional tires operated in similar conditions.

The nylon cord in the carcass and the metal cord in the breaker allow increasing the strength of the tire in the tread area, reducing the temperature at the most stressed points of the tire, protecting its carcass from damage, and preventing the spread of cracks in the tread.

The meridional arrangement of the carcass cord threads increases the elasticity of the tire, increases the grip of the tire with the road, and significantly reduces the wheel rolling losses. The steel cord of the breaker increases the strength of the carcass in the circumferential direction, improves the temperature regime of the tire. Such tires work successfully on roads with improved coverage and in off-road conditions at high speeds.

Frost-resistant tires are designed for use in areas with temperatures below minus 45 °C. Operation of vehicles in these areas on ordinary non-frost-resistant tires is not allowed. current Rules tire operation. Frost-resistant tires are made from rubber that retains sufficient strength and elasticity at low temperatures and ensures normal tire life in these areas.

Tropical climate tires are distinguished by the fact that they are made of heat-resistant rubber, which retains strength and elasticity well at high speeds and high temperatures ambient air, characteristic of countries with a tropical climate. These tires have a carcass made of nylon or high-strength or heavy-duty viscose cord.

Tires with metal studs are used to increase the stability and handling of cars, trucks and buses on slippery icy roads and on ice. Bias and radial tires can be equipped with spikes in the tread. The use of these tires reduces the braking distance of the car by 2...3 times, improves acceleration by 1.5 times and dramatically increases the car's stability against skidding.

Low and extra low profile tires are available for cars, trucks and buses. They have a reduced profile height (for low-profile N/V = 0.7-0.88; for ultra-low-profile N/V< 0,7, где Я - высота профиля; В - ширина профиля), что повышает устойчивость и управляемость автомобиля, обладают большей грузоподъемностью и проходимостью.

1.4 Interaction of tires with the road

When driving a car, the tire operates in very difficult and difficult conditions. During the rolling process, forces of different magnitude and direction act on the tire. To the internal air pressure and the effect of the mass of the car on the tire in a stationary state when the wheel is rolling, dynamic forces are added, as well as forces associated with the redistribution of the mass of the car between the wheels. Forces change their value, and in some cases their direction, depending on the speed of movement and the condition of the road surface, ambient temperature, slopes, the nature of road turns, etc.

Rice. 7 - Forces acting on a fixed (a) and movable (b) wheel.

Under the action of forces during the rolling of the wheel, the tire in various zones is continuously deformed, i.e. its individual parts are bent, compressed, stretched. When driving for a long time, the tire heats up, as a result of which the internal air pressure in the tire increases and the strength of its parts, especially rubber parts, decreases.

The forces and moments acting on the wheel of the car cause reactive forces from the side of the road, which are generally located in three mutually perpendicular directions and are applied to the wheel at the point of its contact with the road base. These reactive forces are called vertical, tangential and lateral. The stationary wheel is subject to the action of one vertical force G from the weight of the car, applied to the wheel axle and equal to the reactive force Z from the side of the road. The vertical force G applied to the wheel axle and its reaction Z from the side of the road are located in the same vertical plane passing through the wheel axle.

In the case of a driven wheel (Fig. 7), the pushing force P from the car is transmitted through the bearing to the wheel axle and causes a tangential reaction X from the side of the road, which is applied to the wheel surface in the zone of its contact with the road and has the direction opposite to the pushing force P,

The rolling of the driven wheel along the supporting surface leads to a violation of the symmetry in the area of ​​contact between the wheel and the road relative to the vertical passing through the center of the wheel, and causes a shift of the reaction Z relative to this vertical forward in the direction of the wheel movement by a certain value i, called the friction coefficient and measured in units of length . The vertical reaction Z, as with a stationary wheel, is numerically equal to the load.

Rice. 8. Forces acting on the driving (a) and braking (b) wheel

The operation of the driving wheel differs from the operation of the driven wheel in that not a pushing force is applied to the driving wheel, but a torque Mk (Fig. 8, a). This moment must balance the total resistance Рresist of all forces opposing the movement (wind, road slope, friction, inertial). As a result, in the contact of the wheel with the road, a reaction occurs Rx = P resist, directed in the direction of motion.

In addition to the function of the driven and leading, the wheel can perform a braking function. The work of the braking wheel can be compared with the work of the leading one. The difference lies in the fact that the braking moment, and hence the tangential reaction of the road, have the opposite direction and are determined by the intensity of braking (Fig. 8, b). The friction coefficient between the wheel and the road surface is in most cases much less than unity, and, consequently, the tangential force, as a rule, is much less than the vertical one.

In addition to these forces, the wheel is often subjected to lateral forces and moments resulting from tilting lateral forces acting on the vehicle chassis, such as centrifugal force when cornering or a mass component due to the slope of the road. On a convex or concave road profile, as well as when driving on a road with bumps, the wheels can also experience the action of lateral forces (Fig. 9), which, provided they are equal on the left and right wheels in magnitude and opposite in direction, will be extinguished on the axle without being transferred to the vehicle itself. The action of the lateral force on the wheel is limited by the adhesion of the wheel to the road. When driving on a convex or concave road profile, or especially on a road with bumps, lateral forces can reach a very significant value.

Thus, the whole complex of external loads acting on the wheel from the side of the road can be represented by three mutually perpendicular forces:

Rice. 9 - The action of forces on the wheels while driving on uneven ground

Vertical reaction Z, the value of which is determined by the total mass of the transported cargo and the car. This load always acts on the wheel, regardless of whether it is moving or not, working as a driven, driving or braking. The value of this load during movement can vary depending on the acceleration (deceleration), the longitudinal and transverse profile of the road, its sinuosity, roadway roughness and speed;

A tangential reaction located in the plane of the wheel (not shown in Fig. 2.4) and resulting from the application of an external moment (torque or braking), pushing force, aerodynamic resistance, rolling friction force to it. The value of this reaction reaches its greatest value usually during braking, however, as a rule, it is limited by the friction coefficient of the wheel with the road surface, which in most cases is less than unity and, therefore, even the most greater value tangential response is generally less than vertical response;

Lateral reaction Y, which is located in a plane perpendicular to the plane of the wheel. Like the tangential reaction, this reaction is also limited by the traction force of the wheel with the road, and, therefore, its maximum value cannot be greater than the vertical force, except when driving on rough roads, deep ruts. Under these conditions, the lateral reaction can significantly exceed the traction force of the wheel with the road.

Of particular interest are tilted wheel rolling and tire side slip. When the car is moving on a turn, the profile of an elastic tire is deformed in the lateral direction under the action of a centrifugal force directed perpendicular to the plane of the wheel (Fig. 2.5). Due to the lateral deformation of the tire, the wheel does not roll in the /-/ plane, but with some slip.

The ability of a tire to lateral deformation has a great influence on the performance of a vehicle, especially its stability and handling. Therefore, the parameters that determine the wheel slip are important characteristic tires.

The slip of the wheel is estimated by the angle d, which is commonly called the slip angle.

Rice. 10 - Deformation of tires when turning the car and the corresponding distortion of the contact patch of the tire with the road due to wheel slip (view A)

The forces applied to the wheel cause lateral deformation of the tire as a result of the tread bending in the lateral direction. When the wheel rolls with a slip, the tire has a complex deformation that is not symmetrical with respect to its vertical plane of symmetry.

For each tire, there is a certain maximum lateral force and a corresponding certain maximum slip angle, at which there is still no large slippage of the tread elements in the lateral direction. The maximum such angle for most domestic passenger car tires is 3 ... 50.

One of the most common cases of wheel rolling is the case of its movement with an inclination to the road. Indeed, on a car, the wheels may lean towards the road due to the use of independent suspension, the slope of the road, and other factors.

The angle of the wheel to the road has a significant impact on the performance of the tire and the trajectory. When an inclined wheel rolls in the plane of rotation from the side of the road, it is also subject to lateral force and torque. The latter tends to turn the wheel in the direction of its inclination. Leaning the wheel towards the road results in lateral deformation of the tire, as a result of which the center of contact between the wheel and the road is shifted in the direction of the wheel lean. With an inclined wheel, the tire tread wears out quickly and unevenly, especially in the shoulder area on the side of the wheel inclination. Thus, leaning the wheel towards the road significantly reduces the life of the tire.

Leaning the wheel towards the road changes the slip angle. When the vehicle is cornering, when the wheel tilts towards the lateral force, the wheel slip increases. This phenomenon is observed in the front steered wheels of cars with independent suspension. Reducing the tire's tendency to side-slip and reducing the wheel's inclination to the road has a positive effect on extending tire life.

2 Features of the operation of car tires

car tire wheel tire

2.1 Tire rolling energy loss

A pneumatic tire, due to the presence of compressed air in it and the elastic properties of rubber, is capable of absorbing a huge amount of energy. If a tire inflated to a certain pressure is loaded with an external force, for example, vertical, and then unloaded, then it can be seen that during unloading, not all energy will return, since part of it spent on mechanical friction in the tire materials and friction in contact is irreversible losses.

When the wheel is rolling, energy is lost to its deformation. Since the energy returned when the tire is unloaded is less than the energy spent on its deformation, then in order to maintain uniform rolling of the wheel, it is necessary to constantly replenish energy losses from the outside, which is done by applying either a pushing force or torque to the wheel axle.

In addition to the resistances resulting from tire deformation losses, the moving wheel experiences resistance due to friction in the bearings, as well as air resistance. These resistances, although insignificant, still belong to the category of irreversible losses. If the wheel moves along a dirt road, then, in addition to the losses listed above, there will also be losses due to plastic deformation of the soil (mechanical friction between its individual particles).

Rolling losses are also estimated by the force of rolling resistance or the power of losses on it. The rolling resistance of a wheel depends on many factors. To a large extent, it is influenced by the design and materials of the tire, speed, external loads and road conditions. The rolling resistance loss of the driven wheel when driving on paved roads consists of losses due to various kinds of friction in the tire. These losses consume a significant portion of the engine power. The energy absorbed by the tire leads to a significant increase in its temperature.

Rice. 11 - Dependence of the rolling resistance force Pk of the tire 6.45-J3R model M-130A with a steel cord breaker on the speed v.

Rolling resistance is highly dependent on rolling speed. Under real operating conditions, rolling resistance can increase by more than 2 times. On fig. 11 shows the test results when the tire had a normal load of 375 kgf and a corresponding air pressure of 1.9 kg/cm2. The tests were carried out on a drum stand with a steady thermal state of the tire. On fig. 11 shows three distinct zones of increasing rolling resistance force. At very low speeds (at the beginning of zone I), the rolling power loss is minimal. These losses are due to compression of the rubber in the contact area of ​​the tire with the road.

In zone II, with an increase in speed, losses increase, and the inertia forces of the wheel movement begin to affect more and more. Starting from a certain speed, the deformation of the tire elements increases significantly, which characterizes the rolling processes in zone III.

An increase in air pressure in the tire leads to a decrease in tire rolling losses on a hard surface in the entire range of speed changes, a decrease in radial deformation, and an increase in its rigidity, which reduces heat loss. It must be remembered that during the rolling process, as the tire heats up, the air pressure in it increases, and the rolling resistance decreases. Warming up a cold tire to steady operating temperature results in a reduction in the rolling resistance coefficient of about 20%. The dependence of rolling resistance on air pressure is an important tire characteristic.

Increasing the load on the wheel at a constant air pressure in the tire increases the rolling resistance force. However, when the load changes from 80 to 110% of the nominal value, the rolling resistance coefficient remains almost constant. An increase in load by 20% above the maximum allowable increases the rolling resistance coefficient by about 4%.

The rolling resistance of the wheel increases slightly with increasing torque and braking torques applied to the wheel. However, the intensity of the increase in losses with braking torque is greater than with the leading one.

For different types of road surfaces, the rolling resistance coefficient varies within the following limits:

Table 1 - Tire rolling resistance coefficients

On paved roads, the rolling resistance of a wheel largely depends on the size and nature of the road irregularities. The rolling resistance in such conditions decreases with increasing wheel diameter.

When driving on a soft dirt road, the rolling resistance depends on the degree of deformation of the tire and the ground. The deformation of a conventional tire on these soils is approximately 30–50% less than on a hard surface. For each tire size and driving conditions, there is a certain air pressure that provides the minimum driving resistance.

2.2 Tire grip

The ability of a normally loaded wheel to perceive or transmit tangential forces when interacting with the road is one of its most important qualities that contribute to the movement of the car. Good grip of the wheel with the road increases handling, stability, braking properties, i.e. traffic safety. Insufficient grip, as statistics show, is the cause of 5 ... 10% of traffic accidents when driving on dry roads and up to 25 ... 40% on wet roads. It is customary to evaluate this quality of the wheel and the road by the coefficient of adhesion F- the ratio of the maximum tangential reaction Rx max in the contact zone to normal reaction or load G acting on the wheel, i.e. F \u003d Rx max / G

There are three friction coefficients: when the wheel rolls in the plane of rotation without slipping or skidding (sliding); when slipping or skidding in the plane of wheel rotation; with side slip of the wheel.

An increase in the coefficient of adhesion can be achieved at the expense of other qualities of the tire. An example of this is the desire to increase wet grip by dissection of the tread pattern, which reduces the strength of the tread elements.

Taking into account the climatic and road conditions in a number of countries, the minimum values ​​of the friction coefficient are set within the range of 0.4 ... 0.6. The coefficient of adhesion depends on the design of the tire, internal pressure, load and other operating conditions, but to a greater extent on road conditions. The range of variation of this coefficient, depending on the design of the tire, is different for different road conditions. When driving on hard, even, dry roads, the adhesion coefficients of tires with various structural elements are close, and their absolute values ​​depend mainly on the type and condition of the road surface, the properties of tread rubbers. The tread pattern under these conditions has the greatest impact on traction. Increasing the saturation of the tread pattern usually improves traction. The influence of the tread pattern is very large when the tire is rolling on smooth surfaces. The tread dissection improves wet traction by better displacing water from the contact area, as well as by increasing the pressure. The expansion of the grooves, their straightening, and the reduction in the width of the protrusions contribute to the acceleration of the exit of water from the contact area. Grip improves with longer tread pattern lugs, and the lowest friction coefficient is observed with square and round lugs. The sipes do not have large flow areas, but they create significant pressure at the edges and, as it were, wipe the road. When moisture is removed, conditions of dry and semi-dry friction arise, which sharply increases the coefficient of adhesion. With a decrease in the height of the protrusions of the tread pattern, the removal of water from the contact zone slows down due to a decrease in the flow sections of the grooves and, accordingly, the grip of the tire with the road deteriorates.

The type of tread pattern also has a significant impact on wet grip. With a longitudinal pattern orientation, hydroplaning1 occurs at a lower speed and with a smaller thickness of the water wedge than in the case of a transverse tread pattern orientation.

Great importance, especially at high speeds, has the thickness of the water layer on the surface of the coating. At speeds over 100…120 km/h and a water layer thickness of 2.5…3.8 mm, even an unworn tread with full height projections does not ensure water removal from the contact area with the road (traction coefficient is less than 0.1).

When driving on soft soils, the grip of a tire depends on surface friction on the ground, the shear resistance of the soil trapped in the depressions of the pattern, and on the depth of the track. The design parameters of the tread pattern are of great importance for the grip of the tire with the road, when the ground is heterogeneous and when a softer layer is located in the upper part, and a relatively hard ground in the lower part.

When driving on soft, viscous soils, grip is more dependent on the self-cleaning of the tread pattern, which can be estimated by the speed of wheel rotation, at which the soil is ejected from the depressions of the pattern by centrifugal force. Self-cleaning is influenced by factors related to soil properties and tire parameters.

A common way to increase tire grip in winter is to use metal studs. However, on roads cleared of snow and ice, the use of tires with studs is impractical, here tires with a winter tread pattern have an advantage.

2.3 Cushioning properties of tires

The carrying capacity of the car must correspond to the carrying capacity of its chassis, one of the most important elements of which is the tire. Under the action of a normal load applied to the wheel, the tire deforms. This occurs with a slight increase (1 ... 21) of the internal air pressure in the tire, since the volume of air during tire deformation is practically! does not change. But, despite such a slight increase in the internal air pressure in the tire, the work of air compression during its deformation is quite significant and amounts to approximately 60% of the total work of deformation at a nominal load and pressure. The remaining 40% is spent on the deformation of the tire material, of which about a third is accounted for by the deformation of the tread.

With an increase in the normal load at a given internal pressure, the value of the air compression force decreases.

Under the action of the load, the distance from the wheel axle to the road is reduced due to a decrease in height and an increase in the width of the tire profile. The value by which the height of the tire profile changed under load when resting on a plane is called normal deformation, and the deformation at any point of the tread in the direction of the wheel radius is called radial deformation at a given point of the tire.

Normal deformation depends on the size and design of the tire, the material from which it is made, the width of the rim, the hardness of the road surface, the air pressure in the tire, the normal load, the circumferential and lateral forces applied to the wheel. It characterizes the degree of loading of the tire, its carrying capacity and durability.

The carrying capacity is also determined by the design parameters of the tire, mainly overall dimensions, internal pressure, number of layers and type of cord in the carcass, profile. An increase in load capacity (but within limited limits) is achieved by increasing the internal pressure in the tire, at which its deflection decreases. However, when the pressure increases, it is required to increase the ply of the tire, which entails undesirable phenomena.

2.4 Durability, wear resistance and tire imbalance

The durability of an automobile tire is determined by its mileage to the limit of wear of the protrusions of the tread pattern - the minimum height of the protrusions is 1.6 mm for passenger car tires and 1.0 mm for truck tires. Such a limitation was adopted from the conditions of traffic safety and protection of the tire carcass from damage in case of wear of the undergroove layer. The durability of a tire depends on the internal air pressure in the tire, the mass load on the tire, road conditions and vehicle driving conditions.

Tread wear resistance is determined by the intensity of tread wear, i.e. wear per unit of mileage (usually I thousand km), under certain road and climatic conditions and driving modes (load, speed, acceleration). The wear intensity Y is usually expressed as the ratio of the decrease in the height A (in mm) of the protrusions of the tread pattern per mileage to this mileage Y = h / S, where S is the mileage, thousand km.

The wear resistance of the tread depends on the same factors as the durability of the tire.

Wheel imbalance and runout increase vibration and make it difficult to drive a car, reduce the life of tires, shock absorbers, steering, increase maintenance costs, impair safety; movement. The influence of unbalance and runout of the wheels increases with increasing vehicle speed. The tire has a significant impact on the total imbalance of the car, since it is the most distant from the center of rotation, has a large mass and a complex design.

The main factors affecting the imbalance and runout of the tire are: the uneven wear of the tread across the thickness and the heterogeneity of the material distribution around the circumference of the tire.

Research conducted at NAMI shows that the most unpleasant consequences of imbalance and runout of wheels with tires assemblies are vibrations of the wheels, cab, frame and other parts of the car. These fluctuations, reaching the limit value, become unpleasant for the driver, reduce the comfort, stability, controllability of cars, increase tire wear.

2.5 Types of tire wear

The task of preventing premature wear and destruction of tires is very complex and is associated with the ability to determine their types, accurately identify the cause that caused each specific tire failure.

All tires that are out of service are divided into two categories: with normal and with premature wear (or destruction). Normal wear or destruction of new and initially retreaded tires is considered to be natural wear that occurs when the tire fulfills the operational mileage standard and does not exclude its restoration. Normal wear or failure of a re-retreaded tire is considered to be wear that occurs after it has fulfilled its service mileage limit, regardless of the suitability or unsuitability of this tire for subsequent retreading. Tires with wear and tear that do not meet the specified criteria are assigned to the 2nd category (prematurely worn).

Tires with category 1 wear are divided into two groups: suitable for retreading, which includes new and previously retreaded tires, and unsuitable for retreading, which includes only tires retreaded more than once.

Tires with wear of the 2nd category are also divided into 2 groups: with wear (destruction) of an operational nature and with a manufacturing defect. Depreciation (or destruction) of a production nature is also divided, in turn, into two groups: manufacturing defects and restoration defects.

A detailed study of the types of wear and destruction of tires will provide a complete analysis of the causes of their premature failure to work and carry out! measures that increase the use of tire resource. Proper use of tires and systematic care of them are the main conditions for increasing their service life. According to NIISHPA and NIIAT, about half of tires fail prematurely due to violation of operating rules. Consider the main reasons that affect the reduction of tire life.

2.6 Tire inflation pressure and tire overload

Pneumatic tires are designed to operate at a specific air pressure. It should be borne in mind that the materials from which the tire is made are not absolutely tight, so air gradually seeps through the walls of the chamber, especially in summer, and the air pressure decreases. In addition, the cause of insufficient air pressure may be damage to the chamber or tire (tubeless), leakage of the valve spool and parts attaching it to the rim (for tubeless tires), untimely check of air pressure. It is impossible to judge the internal pressure in the tire by eye or by the sound when hitting the tire, since in this case you can make a mistake by 20 ... 30%.

Tires with low internal pressure have increased deformations in all directions and, therefore, when rolling, their tread is more prone to slip relative to the road surface, resulting in severe rupture of the tires. At the same time, their elasticity is lost, and strength drops sharply. As a result, tire life is reduced.

The result of operation with reduced air pressure in the tire may be the rotation of the tire on the rim, causing the valve of the chamber to come off or to destroy it in the area of ​​​​the valve attachment. With reduced pressure, the rolling resistance of the wheels increases, and as a result, fuel consumption increases significantly. Accidental significant reduction of air pressure in the tire can be detected in a timely manner by increased tire deformation, by pulling the car towards the tire with low pressure and deterioration of handling. In this case, the tires are quickly overloaded and worn out. With reduced air pressure, tire stiffness decreases and internal friction in the sidewalls of the tire increases, which leads to an annular fracture of the carcass.

A ring break is a tire damage in which the threads of the inner layers of the cord lag behind the rubber, fray and tear along the entire circumference of the side walls. A tire with an annular fracture of the carcass cannot be repaired. An external sign of an annular fracture is a dark stripe on the inner surface of the tire, running along the entire circumference. This band indicates the beginning of the destruction of the cord threads. It is strictly forbidden to drive a car on completely flat tires, even for a distance of several tens of meters, as this causes severe damage to tires and tubes that cannot be repaired.

Increased air pressure also reduces tire life, but not as dramatically as lower pressure. With increased air pressure, stresses in the frame increase. In this case, the destruction of the cord is accelerated, the pressure increases when the tire interacts with the road, leading to intensive wear of the middle part of the tread. The cushioning properties of the tire are reduced and the tire is subjected to greater impact loads. A wheel impact on a concentrated obstacle (stone, log, etc.) leads to a cross-shaped rupture of the tire carcass, which cannot be restored.

With normal air pressure in the tire, tread wear is evenly distributed across its width. With an increase in internal air pressure by 30%, the wear intensity is reduced by 25%. At the same time, there is an increase in wear of the middle of the tire tread in relation to its edges by 20%. The reverse picture is observed when the internal air pressure decreases. Reducing pressure by 30% increases tire wear by 20%. In this case, the tread wear in the middle of the treadmill is reduced by 15% in relation to its edges. Uneven and, in particular, stepped tire wear accelerates the wear of parts and assemblies of the entire vehicle. Tire overloads are mainly caused by loading a car with a mass exceeding its carrying capacity and uneven distribution of cargo in the car body.

The nature of tire damage under increased load corresponds to the damage when operating a tire with low internal air pressure, but wear and damage increase to a greater extent. The normal deflection, the tire contact area, the value and nature of the stress distribution in the contact zone, and, consequently, the intensity of tread wear depend on the normal load.

As a result of overloading the carcass, the side walls of the tires are destroyed, gaps appear in the form of a straight line. Overloading tires also causes additional fuel consumption, loss of car engine power to overcome the rolling resistance of the wheels.

Signs of tire overload: sharp vibrations of the body when the car is moving, increased deformation of the sidewalls of the tires, somewhat difficult driving.

Some drivers believe that in order to reduce the effect of tire overload, they should be pumped up a little. This opinion is wrong. Higher inflation pressures combined with overload will shorten tire life.

When the car is overloaded, the tires are deformed by a greater value, and at the same time, the resultant of all forces applied to the section of the bead ring from the side of the tire moves closer to its outer edge. This contributes to an increase in the deformation of the bead ring and its eversion, which can lead to spontaneous dismounting of the wheel while driving.

2.7 Influence of driving style on tire wear

Inept or careless driving, which is the cause of premature tire wear, manifests itself mainly in sudden braking up to skidding and starting off with slippage, in collisions with obstacles encountered on the roads, in pressing against a curb stone when approaching sidewalks, etc.

When braking hard, the lugs of the tire's tread pattern slip on the road, which increases wear on the projector. The friction of the tire tread on the road when driving on fully braked wheels of the car, i.e. skidding, increases sharply, which increases the heating of the tread and destroys it faster. The greater the speed at which braking begins, and the more abruptly it is carried out, the more the tires wear out. On the road with asphalt concrete pavement while leaving a clearly visible trace, consisting of small particles of tread rubber.

With prolonged skid braking, first, increased local wear of the tire tread “spots” occurs, and then the breaker and carcass begin to collapse. Frequent and sharp braking leads to increased wear of the tread around the wheel circumference and rapid destruction of the carcass. In addition to strong tread wear, sudden braking creates increased stress in the threads of the carcass and the bead of the tire. During sudden braking, large forces arise, which sometimes lead to the separation of the tread from the carcass. With a sharp start and wheel slippage, the tread wears out in the same way as with sudden braking.

When driving inattentively, tires are often damaged by various metal objects found on the roads. Careless access to the sidewalk, crossing over protruding railway or tram tracks can cause the tire to pinch between the rim and the obstacle, resulting in rupture of the sidewalls of the tire carcass, sharp abrasion of the sidewalls and other damage.

When a car moves around a corner, centrifugal force is applied perpendicular to the plane of rotation of the wheels. The sidewalls, bead and tread of the tire in this case experience large additional stresses. On tight turns and increased speed movement, the reaction of the road, which counteracts the centrifugal force, is especially great and tends to tear the tire off the wheel rim, tear the tread off the carcass. This reaction increases tread wear.

As a result of careless driving, stones and other objects can get stuck between the dual tires, which crash into the sidewalls of the tires, destroy the rubber and tire carcass.

At a high vehicle speed and, consequently, a strong deformation, the dynamic load on the tire increases, i.e. friction on the road, impact load, material deformation increase and the temperature in the tire rises sharply, especially at elevated ambient temperatures.

High driving speed can lead not only to increased tread wear, but also to a weakening of the bond between the rubber and fabric layers of the tire, with possible delamination, and to lagging of patches on the repaired areas of the tire and tube.

2.8 Irregular tire maintenance and repair

Unsystematic maintenance and untimely repairs are the main causes of premature tire failure and wear. Failure to comply with the established volume of tire maintenance at the posts of daily, first and second vehicle maintenance leads to the fact that foreign objects stuck outside in the tread (nails, sharp stones, pieces of glass and metal) are not detected and removed in a timely manner, which is why they penetrate into the depth of the tread , then into the frame and contribute to their gradual destruction.

Minor mechanical damage to the tire - cuts, abrasions on the tread or sidewalls, and even more so small cuts, punctures, carcass breaks, if they are not repaired in a timely manner, lead to severe damage that requires repair of an increased volume. This is due to the fact that when the tire rolls along the road, small cuts, punctures and tears in the rubber and carcass tissue are filled with dust, grains of sand, pebbles and other small particles, as well as moisture and oil products. When a rolling tire is deformed, grains of sand and pebbles begin to quickly grind the rubber and tire fabric, increasing the size of the damage. Moisture reduces the strength of the carcass cord threads and causes their destruction, and oil products - the destruction of rubber.

The high temperature of the tire during rolling further accelerates the process of destruction of the tire material in the places of its damage. As a result, a small hole from a cut or puncture gradually grows, causing the tread or sidewall to peel off. Partial rupture of the frame turns into a through one and leads to delamination of the frame and damage to the chamber. A small mechanical damage, not repaired in a timely manner, can cause an unexpected tire rupture along the way as it increases and cause a traffic accident. Late repair of large mechanical and other damage further increases the amount of repair and contributes to the destruction of tires.

A particularly serious reason for the premature destruction of new and retreaded tires is their untimely removal from the vehicle for delivery, respectively, for the first and repeated retreading. If the tire has not been re-retreaded, it means that its durability resource has not been fully used.

Work on new or retreaded tires with a remaining groove depth of the tread pattern in the center of the tread of at least 1 mm for cars and buses, and even more so on tires with a completely worn pattern, in addition to a sharp decrease in the coefficient of adhesion of the tire to the road and, consequently, traffic safety cars, creates favorable conditions for further intensive destruction of the breaker and frame (breakdowns and ruptures). In such cases, due to a decrease in the total thickness of the tread, a decrease in its shock-absorbing and protective properties, the tendency of the carcass in the area of ​​the treadmill to breakdowns and ruptures from shock concentrated forces acting on the tires when rolling along the road increases.

According to NIIShPa, breakdowns and ruptures of the carcass occur in tires with a worn out tread pattern, mainly by 80–90%.

The presence of carcass breakdowns and ruptures on tires reduces the service life of new and retread tires, making them often unsuitable for delivery, respectively, for the first and repeated retreading.

The average mileage of retreaded tires of class 2 (with through damage) is approximately 22% lower than the average mileage of retreaded tires of class 1 (data from NIISHPA). If you allow the tire to work with an exposed breaker or carcass on the running surface, then the tire quickly becomes unusable, since the carcass threads wear out heavily when rubbing against the road.

Exposing the threads in other places of the tire causes a rapid destruction of the carcass fabric under the influence of moisture, mechanical damage and other causes.

Working with cuffs applied to the through damaged area on the inside of the tire without vulcanization is only allowed temporarily as an emergency measure on the way or for tires that are not fit for repair. The operation of a tire with a cuff inserted into it leads to an increase in damage and a gradual grinding of the carcass threads by the cuff.

Running on tires with non-cured tubes causes the patches to come off quickly.

2.9 Violation of the rules for mounting and dismounting tires

The operation of automobiles shows that damage to 10 ... 15% of the tire beads, 10 ... 20% of the chambers and damage to the wheels occur as a result of improper dismantling and mounting of tires. The reasons that reduce the service life of tires and wheels during installation and dismantling are: incompleteness of tires and wheels in size, mounting tires on rusty and damaged rims, non-compliance with the rules and methods of work when performing installation and dismantling operations; the use of faulty and non-standard installation tools, non-observance of cleanliness.

With increased dimensions of the chamber, the formation of folds on its surface and grinding of the walls during operation occur, and with reduced dimensions, the walls of the chamber are significantly stretched and are more prone to rupture during punctures and overload. The reduced dimensions of the rim tape cause part of the rim to be exposed, and the chamber is exposed to the harmful effects of rim corrosion products. In addition, in this case, the edges of the rim tape are destroyed and the chamber is squeezed out in the area of ​​the valve hole, as a result of which its walls are also destroyed. The use of rim tapes with a larger diameter compared to the diameter of the tire leads to the formation of folds, which, during the operation of the wheel, fray the chamber. Tire mismatch with wheel dimensions disrupts its configuration, as a result of which its service life is reduced.

A significant amount of damage to the bead of tires occurs when mounted on dirty, rusty and defective rims. The complexity of mounting and dismounting largely depends on the condition of the wheels: the quality of the paint, the degree of corrosion of the contacting surfaces, the condition of the fastening parts, as well as the degree of "sticking" of the landing surfaces to the tire beads. Damaged rims cause abrasion and various damage to the tire beads. Bumps, scuffs and burrs on deep rims cause ruptures and cuts to the tubes.

Incorrect methods during dismantling and assembly work lead to significant effort and mechanical damage to tire and wheel parts.

The use of a faulty or non-standard mounting tool when mounting and dismounting tires often causes cuts and ruptures of the landing beads and the sealing layer of tires, tubes and rim tapes, mechanical damage to the flanges, landing shelves of rims and wheel rims.

One of the reasons for the reduction in the service life of tires is the lack of cleanliness during assembly and dismantling. Sand, dirt, small objects, getting inside the tires, lead to the destruction of the chambers and damage to individual cord threads of the inner layer of the tire carcass as a result of increased friction of the contacting surfaces.

2.10 Wheel imbalance

When the wheel rotates at high speed, the presence of even a slight imbalance causes a pronounced dynamic imbalance of the wheel relative to its axis. In this case, vibration and runout of the wheel appear in the radial or lateral directions. The imbalance of the front wheels of passenger cars has a particularly harmful effect, worsening the car's handling.

The phenomena caused by imbalance increase the wear of tires, as well as parts of the undercarriage of cars, worsen driving comfort, and increase noise when driving. The presence of an imbalance creates a shock load periodically acting on the tire when the wheel rolls along the road, which causes overstressing of the tire carcass and increases tread wear. A large imbalance is created in tires after repair of local damage with the imposition of cuffs or patches. The mileage of unbalanced repaired passenger car tires, according to NIIAT, decreases by about 25% compared to the mileage of balanced repaired tires. The harmful effects of wheel imbalance increase with increasing vehicle speed, load, air temperature and worsening road conditions.

Depending on the location and function of the wheels (right, left, front, rear, driving and driven), the tires have an unequal load, so they wear unevenly. The convex road profile causes the vehicle's right wheels to be overloaded, which creates a corresponding uneven tire wear.

Traction increases the load and wear on the tires on the drive wheels of the vehicle compared to the tires on the driven wheels. If you do not rearrange the wheels on the car, then the uneven wear of the tire tread pattern can average 16 ... 18%. However, frequent rearrangement of wheels (during each maintenance of the car) can lead to an increase in the specific wear of the tire tread by 17–25% compared to only a one-time shift.

In foreign literature, a significant effect of tire pre-running on wear is noted. If new tires at the beginning of their operation (for the first 1000 ... 1500 km) are given a lower load (50 ... 75%), and then gradually increase it, then the total mileage of the tires run in this way increases by 10 ... 15%.

A significant cause of premature tire wear is improper use. Thus, tires with a tread pattern of increased cross-country ability, when used mainly on paved roads, wear out prematurely as a result of increased pressure on the road. In addition, the off-road tread pattern has reduced grip on hard surfaces, which leads to tire slippage on wet and icy surfaces and can cause a skid and an accident.

2.11 Proper selection and fitting of vehicles with tires

Tires, depending on the working conditions, must have certain operational qualities. For the operation of vehicles in difficult road conditions and off-road, tires with high cross-country ability and reliability are desirable. In the southern regions, as well as in the middle lane, it is necessary to use tires with high heat resistance, and in the northern regions - with high frost resistance.

The rational choice of tires for automobiles means the choice of such types, sizes and models of tires that would have the combination of the highest qualities under specific operating conditions. The selection of tires by size, model, ply rate (load capacity index), type of tread pattern and their coordination with each specific model of a car manufactured by the automotive industry is carried out in accordance with OST 38.03. industry."

When choosing tires, the type of construction is determined. For normal road climatic conditions operation choose tires of conventional designs - chamber or tubeless, diagonal or radial mass production. Depending on the predominance of certain types of road surfaces, the tread pattern of tires of a conventional design is chosen.

For the operation of vehicles on paved roads, tires with a road tread pattern are chosen. For work on unpaved roads and paved roads, tires with a universal tread pattern are used in approximately equal proportions. When operating in difficult road conditions, tires with an off-road tread pattern are chosen.

When choosing tires, their overall dimensions, carrying capacity and permissible speeds are taken into account, which are determined according to the technical characteristics of the tires.

The load carrying capacity of a tire is measured by the maximum allowable load on it. The criterion of carrying capacity is the main condition for the correct choice of tire size, ensuring their operation without overload. To determine the required tire size, first find out the greatest load (in kgf) on the wheel of the car, and then, accordingly, according to it state standard or specifications select the size of the tires so that the maximum allowable load on the tire is equal to or exceeds by 10 ... 20% the allowable load on the car wheel. The choice of tires with a certain margin of allowable load ensures their greater durability in operation. Along with the load on the wheel, when choosing a tire size, vehicle speeds are taken into account, which should not exceed the permissible speeds for tires.

Tires (including a spare) of the same size, model, design (radial, diagonal, chamber, tubeless, etc.) with the same tread pattern are installed on the car.

When partially replacing tires that have failed in operation, it is recommended to equip the car with tires of the same size and model as on this car, since tires of the same size, but different models, can be of different designs, have different types of tread pattern, rolling radius , grip and other performance characteristics.

The use of imported tires and their installation on cars of individual owners should take into account the modes of operation of cars.

Tires retreaded according to the 1st class are used without restrictions on all axles of passenger cars. The determination of the recovery class is made in accordance with the rules for the operation of tires (see Table 5.2).

To ensure traffic safety, it is not recommended to install tires with repaired local damage on the wheels of the front axles of cars. Tires with anti-skid studs can be used to improve the grip qualities of tires and increase the safety of vehicles on snowy and icy roads. Recommendations for studding tires when operating rolling stock of road transport using studded tires are set out in the Instructions for the use of anti-skid studs. Tires with anti-skid spikes are installed on all wheels of the car.

Rearrangement of studded tires according to technical necessity is carried out without changing the direction of rotation of the wheels.

Vehicles intended for operation in the regions of the Far North and equated to them (at temperatures below minus 45 ° C) should be equipped with tires marked “North”, in the northern version.

When operating vehicles mainly on soft soils and off-road, they must be equipped with tires with an off-road tread pattern. Long-term use of these tires on paved roads is not recommended.

2.12 Repair of tires in a car company

The technological process of tire repair consists of simple operations. Tires accepted for repair are washed in a special bath and dried in drying chambers at a temperature of 40 ... 60 ° C for 2 hours. The quality of tire repair is extremely affected by their drying. When repairing insufficiently dried tires, the quality of their vulcanization deteriorates sharply due to the formation of vapor locks.

When preparing a tire for repair, the damaged areas are cleared in accordance with the intended repair method and roughened. In case of through damage, the repair method is used by inserting a cone. In this case, it is advisable to install a cuff on the inside, which would protect the carcass from destruction and increase the service life of the repaired tires. Nail through punctures are repaired by installing a rubber fungus.

For ease of access to the inside of the tire when cutting through damage, mechanical, hydraulic or pneumatic expanders are used. Damaged edges are cut with a special knife at an angle of 30 ... 40 °. The areas prepared for repair are roughened inside and outside the tire. Roughing provides a strong adhesion of the repair materials to the surface of the tires. For internal roughening, a device is used, consisting of an electric motor with a power of 0.8 ... 1.0 kW with a flexible shaft, on which a steel disk brush is fixed.

For external roughening, a roughening machine is used, consisting of an electric motor with a power of 2.2 ... 3.0 kW (at a speed of 1400 rpm), at one end of which a disk rasp is fixed, and at the other - a steel brush. After roughening is completed, the tire is cleaned of roughing dust and the first control inspection of the prepared surface is carried out, paying attention to the quality of cutting and roughening. Then the prepared surface of the tire is smeared 2 times with a solution of glue (1 part of glue to 5 parts of gasoline), and the surface of the patch is coated with glue with a concentration of 1:10.

After each lubrication, the applied layer of glue is dried at a temperature of 30 ... 40 ° C for 3D ... 40 minutes. The glued and dried tire is subjected to a second inspection, and then the damage is repaired and a third inspection and vulcanization is carried out. Vulcanization is designed to create a strong connection between repair materials and the tire and turn the raw plastic repair rubber into a resilient elastic rubber.

For vulcanization of external damage to tires located along the tread, sidewall and bead, a sector shape is used, and for vulcanization of internal and through damage to tires along the carcass, a sector is used. Vulcanizing equipment is heated with steam from an electric or electric oil apparatus.

Punctures of tubeless tires are repaired without dismantling them from the wheels. Holes of small punctures with a diameter of up to 3 mm are filled with a special paste using a syringe. Punctures of large sizes with a diameter of up to 5 mm are repaired using rubber plugs, on the outer surface of which there are annular protrusions, or plugs made in the form of a fungus.

When setting plugs in the form of a fungus, remove the tire from the rim. At the same time, the fungus rod is tightly inserted into the puncture hole, and the head is glued onto the inner surface of the sealed layer. Punctures and cuts with a diameter of more than 5 mm are repaired in a tire repair shop in the usual way.

For chambers, the technological repair process consists of revealing hidden damage to the chamber by immersing it, filled with air, into a tank with water and preparing the damaged areas for repair (they clean and apply glue with a concentration of 1: 8 twice). After each spread, the glue is dried at a temperature of 20 ... 25 ° C for 30 ... 40 minutes. At the same time, a patch is prepared, which should cover the breakthrough along the circumference by 20 ... 30 mm. The patch is cut out of raw rubber or an old camera. In the latter case, the surface of the patch is roughened and smeared with glue. After that, the chambers are vulcanized on tiles heated by steam or electricity. Vulcanization temperature 150…162 °С, duration 15…20 min.

3 Features of the operation of winter tires on trucks

3.1 winter non-studded tires

The tread depth on winter tires is significantly greater than on summer tires, which allows you to get more traction on snow. These tires are made from a softer rubber that remains flexible even at low temperatures. Almost every manufacturer has a separate line of such tires, they are used for the winter season, for very harsh conditions, for example, in Norway or in our Siberia.

For long-distance transportation in Russia, there are tires that can be used all year round. With truck tires for the winter season, the problem is solved quite simply - a number of manufacturers have tires for the drive axle that can be positioned as winter, they are year-round, and at the same time allow you to get good grip in winter throughout the life of the tire. These are all-weather, or as they are called differently, tires for difficult climatic conditions. The specifics of long-haul transportation in Russia is that the carrier often has to travel from Surgut to Krasnodar, actually crossing three climatic zones.

Dealers have separate lines of tires that are positioned as designed for operating conditions associated with constant ice. But it cannot be said that the volume of implementation and use of such tires is very large. As a rule, we are talking about carriers that travel from St. Petersburg along the winter coast to Norway, where ice can be several centimeters thick. In such conditions, both chains and special tires are used, which are not used year-round, because on asphalt they will wear out in a short period of time. But in this case it is inappropriate to talk about the mass use of such tires. Rather, these are isolated cases.

There are special models for winter use, but they are not very popular in Russia. This is due to the subjectivity of opinion, when consumers draw an analogy with passenger tires, when a set of winter tires is changed to summer tires at the end of winter. Winter tires are also suitable for use in summer. It's just that the structure of the rubber compound of the treads and tread patterns is such that they are much more efficient in winter than tires of other models.

In a number of European countries, during the winter period, there are requirements in connection with which trucks weighing over 3.5 tons must be equipped with winter tires marked "M + S" on the drive axle in winter. It is allowed to use all-season tires that also meet the requirements of Directive 92/23/EEC and have the symbol "M + S" and a residual tread depth of at least 4 mm. The application of the “M+S” marking to all-season truck tires is determined mainly by the value of the negative tread fraction. Winter truck tires with a tread pattern and design specifically designed to provide increased grip on icy and snow-covered roads are additionally marked with “SNOW” or a sign in the form of a mountain peak with three peaks and a snowflake inside it. Based on the operating conditions, the carrier himself determines the need to use winter truck tires with increased traction.

Usually, experienced specialists buy new summer truck tires before the winter season. They have a high tread and will handle winter conditions well. At the same time, tires do not need to be changed at the onset of summer, and they provide good fuel efficiency. The disadvantages of such operation of tires are that it is very difficult to change tires for the next winter, because during the winter, spring, summer and autumn they have not yet fully exhausted their resource, and here the driver faces a difficult choice. He will either have to drive on tires with low tread in winter and endanger himself and the load, or change tires before winter with new ones and incur additional costs. Changing tires in winter will at first glance increase operating costs, but in the long run it will reduce risks and improve the quality of transportation.

Some manufacturers are releasing second-generation tires that use 3D sipe technology. The slats are small slots, inside they have a 3D structure, that is, they function on the principle of egg cells nested one inside the other. When they work in a vertical direction and they cannot be moved relative to each other, it turns out that the bus block acts as a single unit. As soon as the car begins to slip or brake intensively, that is, a longitudinal load appears, these lamellas move apart from each other and, in fact, the number of tire engagement ribs practically doubles.

This technology allows the tire to behave very confidently on wet, snowy, icy surfaces and at the same time not to lose grip during summer operation. Such tires allow several times to increase the grip of tires with the road, regardless of the surface. They are used in the Russian market, and even those drivers who are forced to overcome mountains along their routes, travel beyond the Urals, in a word, operate them in difficult conditions, speak very positively about them.

Rice. 12 – Lamellas with 3D structure

3.2 Studded tires

Studded tires are of limited use in certain operating conditions. Most modern manufacturers do not prioritize spikes. The tire can be of the same model, but in two versions: studded and non-studded. On the tire for which studding is provided, there are certain marks - points on the tread. The process itself is quite simple and does not apply to high-tech. A hole of a certain depth is drilled into the tread, while each tire has its own recommended drilling depth. Then a spike is inserted into the hole using special equipment. In this case, the spikes can vary in shape, height, diameter.

Year round tires for difficult conditions generally not intended for studding, because their structure is such that they are very heavily lamellae. As for tires of other segments, for some tires, if necessary and dictated by conditions, manufacturers provide studding schemes. Most often these are off-road tires or for construction (for combined conditions). But in general, operating conditions are such that spikes may be needed infrequently. Therefore, a number of manufacturers are inclined to believe that studs are generally not needed for road transport.

Studded truck tires - a rarity in Russia. Such tires are mainly used in the Scandinavian countries on buses and transport with high-value goods. Studded tires add weight to the tire structure, which increases fuel consumption and is also unsafe for vehicles driving behind.

In European countries, the use of winter studded tires for trucks is prohibited. As a rule, leading tire companies do not produce such tires, since the high specific pressure of the stud on the road surface leads to the destruction of roads. Snow chains are recommended for difficult terrain.

Conclusion

In this paper, the fundamentals of the design of car tires, their performance characteristics, as well as their impact on the quality of transportation were considered. Having studied this topic we can conclude that right choice the type and model of car tires, as well as their competent technical operation and maintenance, increase the comfort of driving a car, its safety, the safety of cargo and the cost of transportation and maintenance of rolling stock.

List of sources

1) www.euro-shina.ru

2) www.sokrishka.ru

3) www.shinexpress.ru

4) www.sutopolomka.ru

5) www.srotector.ru

6) www.shinam.ru

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FEDERAL AGENCY FOR TECHNICAL REGULATION AND METROLOGY
	NATIONAL STANDARD RUSSIAN FEDERATION	GOST R 52800-2007 (ISO 13325:2003)

TIRE CONTACT NOISE MEASUREMENT
WITH ROAD SURFACE
WHEN COASTING

About the standard

1. PREPARED by the Open Joint Stock Company "Research Center for Control and Diagnostics of Technical Systems" (OJSC "SRC KD") on the basis of its own authentic translation of the standard specified in paragraph 4

2. INTRODUCED technical committee according to standardization TC 358 "Acoustics"

3. APPROVED AND INTRODUCED BY Order No. 404-st of December 25, 2007 of the Federal Agency for Technical Regulation and Metrology

4. This standard is modified in relation to the international standard ISO 13325:2003 “Tires. Tires - Coast-by methods for measurement of tire-to-road sound emission by means of technical deviations explained in the introduction to this standard.

Introduction

This standard has the following differences from the international standard ISO 13325:2003 applied in it:

In accordance with the requirements of GOST R 1.5-2004, from the section "Normative references" are excluded international standards, not accepted as national standards of the Russian Federation. The section is supplemented by the following national and interstate standards: GOST 17187-81 (instead of IEC 60651:2001), GOST 17697-72 (instead of the one specified in the Bibliography structural element ISO 4209-1), GOST R 52051-2003 (instead of the one specified in the structural element "Bibliography" ISO 3833), GOST R 41.30-99 (instead of ISO 4223-1), GOST R 41.51-2004 (instead of ISO 10844);

Subsection 6.1 excludes information on the timing of calibration of measuring instruments, since the frequency of verification is established by standards State system ensuring the uniformity of measurements. The last paragraph has been deleted from the same subsection as it repeats the test site requirements of section 5;

The last phrase from A.1.7 (Appendix A) has been deleted. This phrase is added as a note at the end of A.1.9, where reference speed was first mentioned;

From the last paragraph A.2.3 (Appendix A), the phrase "This gives the desired value of the sound level L R» as duplicating the first phrase of the first paragraph of the specified paragraph;

Introduction date - 2008-07-01

1 area of ​​use

This International Standard specifies methods for measuring the noise produced by tires in contact with the road surface when they are mounted on a coasting vehicle (hereinafter referred to as TS) or a towed trailer, i.e. when trailer or TS rolls freely with the engine, transmission and all auxiliary systems not necessary for steering off TS. Insofar as noise when tested by the method using TS more tire noise floor, the trailer test method can be expected to provide an objective assessment of the tire noise floor.

This standard applies to cars and trucks. TS, as they are defined in GOST R 52051. The standard is not intended to be defined as a proportion of tire noise in total noise. TS, moving under the action of engine thrust, and the noise level of the traffic flow at a given point in the terrain.

2. Regulatory references

This standard uses normative references to the following standards:

GOST R 41.30-99 (UNECE Regulation No. 30) Uniform provisions concerning the approval of tires for motor vehicles and their trailers

GOST R 41.51-2004 (UNECE Regulation No. 51) Uniform provisions concerning the certification of vehicles with at least four wheels in connection with the noise they produce

GOST R 52051-2003 Motor vehicles and trailers. Classification and definitions

GOST 17187-81 Sound level meters. General technical requirements and test methods (IEC 61672-1:2002 "Electroacoustics. Sound level meters - Part 1. Requirements", NEQ)

GOST 17697-72 Cars. Wheel rolling. Terms and Definitions

Note - When using this standard, it is advisable to check the validity of the reference standards according to the "National Standards" index, compiled as of January 1 of the current year, and according to the corresponding information indexes published in the current year. If the reference standard is replaced (modified), then when using this standard, you should be guided by the replacing (modified) standard. If the referenced standard is canceled without replacement, the provision in which the reference to it is given applies to the extent that this reference is not affected.

3. Terms and definitions

This standard uses the terms GOST R 41.30 and GOST 17697, as well as the following designations and terms with their respective definitions.

3.1. Tire classes

C1. Car tires TS.

C2. Truck tires TS with LI in single number not exceeding 121 and speed category N or higher.

C3. Truck tires TS with an LI in single number not exceeding 121 and a speed category of M or lower, or a tire with an LI in single number not less than 122.

3.2 bearing capacity index LI ( load index): Numeric code that characterizes the maximum load that the tire can withstand in the operating conditions specified by the tire manufacturer at a speed of movement TS corresponding to the tire speed category.

NOTE If LI consists of two numbers, only the first number is referred to. For tires whose load carrying capacity index is unknown, reference is made to the maximum load rating printed on the sidewall of the tire.

4. General provisions

The methods specified in this standard are based on the use of a moving TS(see Appendix A) or a towed trailer (see Appendix B). Tire noise measurements are made while driving TS or trailer coasting.

The measurement results correspond to the objective value of the sound level emitted under the specified test conditions.

5. Test site (polygon)

The test site must be flat and level. Conditions dissemination sound between the sound source and the microphone must comply with the conditions of a free sound field above the sound-reflecting plane with an indicator of acoustic conditions not more than 1 dB. These conditions are considered to be met if there are no sound-reflecting objects such as fences, barriers, bridges or buildings within 50 m of the center of the test area.

The surface of the test area must be dry and clean in all directions. The pores must also be dry. The test site and its surface must meet the requirements applications I GOST R 41.51(see figure 1).

6. Measuring instruments

6.1. Acoustic measuring instruments

The sound level meter must meet the requirements for sound level meters of the 1st accuracy class according to GOST 17187.

Measurements must be made using the frequency response BUT and time characteristics F.

Before and after measurements, in accordance with the manufacturer's instructions or using a standard sound source (for example, a pistonphone), the sound level meter is calibrated, the result of which is entered into the measurement protocol. The calibrator must comply with the 1st class according to .

If the sound level meter readings obtained during calibration differ by more than 0.5 dB in a series of measurements, results tests should be invalidated. Any deviations must be recorded in the test report.

Windscreens are used in accordance with the microphone manufacturer's recommendations.

1 - trajectory of movement; 2 - position of the microphone; BUT - BUT, AT - AT, E - E, F - F- reference lines

Note - The movement of the vehicle occurs as prescribed in Appendix A, the trailer - in accordance with Appendix B.

Figure 1 - Test site and surface

6.2. Microphones

The test uses two microphones, one on each side. TS/trailer. In the immediate vicinity of the microphones, there should be no obstacles that affect the acoustic field, and there should be no people between the microphone and the sound source. The observer or observers must be positioned so as not to influence the results of the sound measurement. The distances between the positions of the microphones and the center line of movement on the test site shall be equal to (7.5 ± 0.05) m. TS along the center line of motion as shown in Figure 1, each microphone shall be positioned 1.2 ± 0.02 m above the test site surface and shall be oriented according to the sound level meter manufacturer's recommendations for free field conditions.

6.3. Temperature measurements

6.3.1. General provisions

Measuring instruments for the temperature of air and the surface of the test track must have the same accuracy of at least ± 1 °C. Infrared thermometers should not be used to measure air temperature.

The type of temperature sensor should be specified in the test report.

Continuous logging via analog output can be applied. If this is not possible, then discrete values ​​are determined temperature.

Measurements of the air and surface temperature of the test area are mandatory and must be carried out in accordance with the instructions of the manufacturers of the measuring instruments. Measurement results are rounded to the nearest whole number of degrees Celsius.

The temperature measurements must exactly time the sound measurements. In both test methods (with TS and trailer) alternatively, the mean of a set of results can be used temperature measurements at the beginning and end of the test.

6.3.2. Air temperature

The temperature sensor is located in a free place near the microphone, so that it can perceive air currents, but is protected from direct sunlight. The last requirement is provided by any shading screen or other similar device. In order to minimize the influence of surface thermal radiation on weak air currents, the temperature sensor is located at a height of 1.0 to 1.5 m above the surface of the test area.

6.3.3. Test site surface temperature

The temperature sensor is located in a place where it does not interfere with sound measurements and its readings correspond to the temperature of the wheel tracks.

If any device is used in contact with the temperature sensor, a reliable thermal contact between the device and the sensor is obtained by means of a thermally conductive paste.

If an infrared thermometer (pyrometer) is used, then the height surface temperature sensor choose so as to obtain a spot with a diameter of at least 0.1 m.

It is not allowed to artificially cool the surface of the test area before or during testing.

6.4. Wind speed measurements

The instrument for measuring wind speed must provide measurement results with an error not exceeding± 1 m/s. Wind speed measurements are carried out at the height of the microphone between the lines BUT - BUT and AT - AT no further than 20 m from the center line of movement (see Figure 1). The direction of the wind relative to the direction of movement is recorded in the test report.

6.5. Movement speed measurements

The means of measuring the speed of movement must provide the results of measuring the speed of the vehicle or trailer with an error of not more than ± 1 km/h.

7. Weather conditions and background noise

7.1. Weather conditions

Measurements are not carried out under adverse weather conditions, including gusts of wind. The test is not carried out if the wind speed exceeds 5 m/s. Measurements are not made if the air or surface temperature of the test site is below 5 °C or the air temperature is above 40 °C.

7.2. Temperature correction

Temperature correction is applied only to tires of classes C1 and C2. Each measured sound level Lm, dBA, corrected by the formula

L = Lm + K D T,

where L- corrected sound level, dBA;

K is a factor that:

For class C1 tires, it is minus 0.03 dBA/°C when the measured surface temperature of the test area is more than 20°C, and minus 0.06 dBA/°C when the measured surface temperature of the test area is less than 20°C;

For class C2 tires it is minus 0.02 dBA/°C;

D T- difference between the reference value of the surface temperature of the test area of ​​20 °C and the temperature of the same surface t during sound measurement, °C

D T = (20 - t).

7.3. Background noise sound level

The sound level of background noise (including wind noise) must be at least 10 dBA lower than the measured sound level resulting from the interaction of tires with the road surface. The microphone may be provided with a windscreen, the effect of which on the sensitivity and directivity of the microphone is known.

8. Tire preparation and accessories

The tires under test shall be mounted on a rim recommended by the tire manufacturer. The rim width must be specified in the test report.

Tires for which special installation requirements are imposed (hereinafter referred to as special tires), having, for example, an asymmetric or directional pattern tread, must be installed in accordance with the specified requirements.

Tires and rims assembled into a wheel must be balanced. Tires must be run in before testing. The break-in must be equivalent to a 100 km run. Special tires must be run in according to the same requirements.

Regardless of tread wear due to break-in, tires must have full tread depth.

Tires of classes C1 and C2 must be warmed up immediately before the tests under conditions equivalent to driving at a speed of 100 km/h for 10 minutes.

Annex A

(mandatory)

Vehicle Method

A.1. General provisions

A.1.1. test vehicle

Test engine TS shall have two axles with two test tires on each axle. TS must be loaded to create a load on the tires in accordance with the requirements of A.1.4.

A.1.2. Wheelbase

Wheelbase between two test axles TS must be:

a) not more than 3.5 m for class C1 tires and

b) not more than 5.0 m for tires of classes C2 and C3.

A.1.3. Measures to Minimize the Impact TS for measurements

a) Requirements

1) Do not use splash guards or other splash guards.

2) In the immediate vicinity of tires and wheel rims, it is not allowed to install or store elements that can shield sound radiation.

3) Wheel alignment (toe-in, camber and caster angle) must be checked on an unladen TS and must comply with the manufacturer's recommendations. TS.

4) Do not install additional sound-absorbing materials in the wheel arches and on the lower part of the body TS.

5) Windows and skylight TS must be closed during testing.

1) Elements TS, whose noise may be part of the background noise, should be changed or removed. All taken from TS elements and design changes must be specified in the test report.

2) During the test, it must be checked that the brakes do not create characteristic noise due to incomplete release of the brake pads.

3) Do not use all-wheel drive four-wheeled cars TS and trucks with reduction gears on axles.

4) The condition of the suspension must be such that it prevents an excessive decrease in the clearance of the loaded in accordance with the test requirements TS. Body Leveling System TS relative to the road surface (if any) must provide the same clearance during testing as that of an unladen TS.

5) Before testing TS must be thoroughly cleaned of dirt, soil or sound-absorbing materials, unintentionally adhering during break-in.

must satisfy the following conditions.

a) The average load on all tires shall be (75 ± 5)% LI.

b) There shall be no tires loaded with less than 70% or more than 90% LI.

A.1.5. Tire pressure

Each tire must be inflated to pressure (cold tires):

where P t- pressure in the test tire, kPa;

Rr- nominal pressure, which:

For a standard Class C1 tire is 250 kPa and

For a reinforced (reinforced) tire of class C1 is 290 kPa, and for tires of both classes, the minimum test pressure must be P t= 150 kPa;

For tires of classes C2 and C3, it is indicated on the sidewall of the tire;

Q r

A.1.6. Vehicle driving mode

test TS should be close to the line BUT - BUT or AT - B with the engine off and the transmission in neutral, moving as closely as possible along the trajectory of the “center line of motion”, as shown in figure 1.

A.1.7. Speed ​​range

test speed TS at the time of passing the microphone should be:

a) 70 to 90 km/h for tires of classes C1 and C2 and

b) 60 to 80 km/h for class C3 tyres.

A.1.8. Sound Level Registration

Record the maximum sound levels during the passage of the test TS between lines BUT - BUT and AT- 6 in both directions.

The measurement results are invalidated if too large a difference between the maximum and total sound levels is recorded, provided that such a maximum is not reproduced in subsequent measurements at the same speed.

NOTE At certain speeds, tires of some classes may have maxima ("resonances") in the sound level.

A.1.9. Number of measurements

On each side TS perform at least four sound level measurements at the speed of the test TS above the reference speed (see A.2.2) and at least four measurements at the speed of the test TS below reference speed. test speed TS must lie within the speed range given in A.1.7 and must differ from reference speed to approximately equal values.

Note - Reference speeds are given in A.2.2.

1/3-octave noise spectra should be measured. The averaging time must match time response of the sound level meter F. Noise spectra should be recorded at the moment when the sound level of the transmitted TS reaches a maximum.

A.2. Data processing

A.2.1. Temperature correction

A.2.2. Reference speeds

The following speed reference values ​​are used to normalize noise to speed. v ref:

80 km/h for class C1 or C2 tires and

70 km/h for class C3 tires.

A.2.3. Normalization relative to speed

Desired test result - sound level L R- obtained by calculating the regression line with respect to all pairs of measured values ​​(velocities v i temperature-corrected sound level L i) according to the formula

L r=` L - a · `v,

where ` L- arithmetic mean value of temperature-corrected sound levels, dBA;

Where is the number of terms P? 16 when using measurements taken for both microphones for a given regression line;

average speed where

a- slope of the regression line, dBA per decade of speed,

Additional sound level L v for arbitrary speed v (from the considered speed interval) can be determined by the formula

A.3. Test report

The test report must contain the following information:

b) meteorological conditions, including air and test track surface temperatures for each run;

c) the date and method of checking the conformity of the surface of the test area with the requirements of GOST R 41.51;

d) the width of the rim of the wheel under test;

e) tire data, including manufacturer's name, trade name, size, LI or load capacity, speed category, pressure rating and tire serial number;

f) the name of the manufacturer and the type (group) of the test TS, model year TS and information about any modifications ( design changes) TS regarding sound;

g) the tire load in kilograms and in percent LI for each tire tested;

h) cold tire pressure for each test tire, in kilopascals (kPa);

i) the speed of passing the test TS past the microphone;

j) maximum sound levels for each microphone on each pass;

k) maximum sound level, in dBA, normalized to the reference speed and corrected for temperature, expressed to one decimal place.

Tables A.1, A.2 and A.3 show, respectively, the forms of presentation of the necessary information for the test report, data on the test conditions of the method as using TS, and using a trailer, and test results TS.

Table A.1 - Test report

Road noise testing of tires in accordance with GOST R 52800-2007 (ISO 13325:2003)
Test report No.: __________________________________________________________________________
Tire data (brand name, model name, manufacturer):
__________________________________________________________________________________________ __________________________________________________________________________________________
Tire manufacturer's address: _________________________________________________________________ __________________________________________________________________________________________
Tire size: _____________	Tire serial number: _________________
Nominal pressure: ____________________________
Tire class: (check one box)	Passenger cars TS(S1)
	Freight TS(S2)
	Freight TS(S3)
Annexes to this protocol: ____________________________________________________________ __________________________________________________________________________________________
Declared sound level: ____________dBA
at reference speed:
Comments (at other speeds) _______________________________________________________________
Responsible for testing: _________________________________________________________
Name and address of the applicant: _______________________________________________________________ __________________________________________________________________________________________
Date of the protocol: ______________________________ Signature:

Table A.2 — Additional data/information regarding tire noise tests

This form is an annex to the Test Report No. ______________ Date of testing: ________________________________________________ Test vehicle/trailer [type, manufacturer, model year, modifications (constructive changes), hitch length]: _________________________________________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________ Place of testing: ______________________________________________________________ Date of certification of the test site: _________________________________________________ The test site is certified for: __________________________________________________________ The same as a percentage (%) LI: front left: _______ front right: _______ rear left: _________ rear right: __________ Tire pressure, kPa front left: _______ front right: _______ rear left: _________ rear right: __________ Test wheel rim width: __________________________________________________________ Temperature sensor type: ___________________ for air: ____________ for the surface of the test site: __________________

Table A.3 - Test results for a motor vehicle

Test number	Speed, km/h	Direction of travel	Sound level (without temperature correction) on the left side, dBA	Sound level (without temperature correction) on the right side, dBA	Air temperature, °C	Track surface temperature, °C	Sound level (with temperature correction) on the left side, dBA	Sound level (with temperature correction) on the right side, dBA	Notes
Declared sound level _________dBA
NOTE The declared sound level value should be calculated at the reference speed from the regression analysis after temperature correction and rounded to the nearest whole value.

Annex B

(mandatory)

Trailer method

B.1. Traction vehicle and trailer

B.1.1. General provisions

The test complex should consist of two parts: traction TS and trailer.

B.1.1.1. Traction vehicle

B.1.1.1.1. Sound level

Traction motion sound TS should be minimized as much as possible by appropriate measures (installation of low-noise tyres, screens, aerodynamic fairings, etc.). Ideally, the sound level traction vehicle must be at least 10 dBA below the total sound level traction vehicle and trailer. In this case, there is no need to carry out multiple measurements with a traction TS. It is possible to increase the accuracy of measurements due to the lack of subtraction of the sound level of the traction TS. The required level difference and calculated tire sound level are given in B.4.

must not be changed during test runs of the traction TS with a trailer. To ensure a stable load during testing, the traction TS if necessary, load with ballast.

B.1.1.2. Trailer

B.1.1.2.1. Single axle frame trailer

The trailer must be a single-axle frame trailer with a hitch and a device for changing the load on the tires. Tires shall be tested without fenders or wheel covers.

B.1.1.2.2. Drawbar length

Drawbar length measured from the center of the drawbar TS to the axle of the trailer must be at least 5 m.

B.1.1.2.3. Track width

The horizontal distance measured perpendicular to the direction of travel between the centers of the contact patches of the trailer tires with the road surface shall not exceed 2.5 m.

B.1.1.2.4. Collapse and convergence

The camber and toe angles of all tested tires under test conditions shall be zero. The tolerance for camber should be ± 30" and for toe angle ± 5".

B.2.

For tires of all classes, the test load shall be (75 ± 2)% of the rated load Q r

B.2.2. Tire pressure

Each tire must be inflated to pressure (cold tires)

where P t- test pressure, kPa;

Rr- nominal pressure, which is equal to:

250 kPa for standard class C1 tires;

290 kPa for reinforced tires of class C1;

The pressure value indicated on the sidewall for tires of classes C2 and C3;

Q r- maximum load mass corresponding to the LI of the tire;

B.3. Measurement technique

B.3.1. General provisions

When carrying out tests of this type, two groups of measurements must be performed.

a) First test the traction TS and register the measured sound levels in accordance with the methodology described below.

b) Then test traction vehicle together with the trailer and record the total sound levels.

The sound level of tires is calculated according to the procedure given in B.4.

B.3.2. Vehicle location

Traction TS or traction TS together with the trailer must approach the line E - E with the engine turned off (muffled) at neutral speed with the clutch disengaged; middle line TS should coincide as closely as possible with the center line of motion, as shown in Figure B.1.

B.3.3. Travel speed

Before entering the test area ( E - E or F - F, see figure B.1) traction TS must be accelerated to a certain speed so that the average coasting speed TS with the engine off, together with the trailer between the lines A - A and AT - AT test area was (80 ± 1.0) km/h for tires of classes C1 and C2 and (70 ± 1.0) km/h for tires of class C3.

B.3.4. Required measurements

B.3.4.1. Noise measurements

Record the maximum values ​​of the sound levels measured during the passage of the tested tires between the lines. A - A and B - B track test area (see Figure B.1). Additionally, when passing the measurement zone, it is necessary to register the sound level values ​​for each microphone at time intervals not exceeding 0.01 s, using an integration time equivalent to the time characteristic F sound level meter. This data in the form of sound levels versus time is needed for further processing.

1 - trajectory of movement; 2 - reference point TS; 3 - position of the microphone; A - A and A" - A", B - B and B" - B", E - E and E" - E", F - F and F" - F", O - O and O" - O"- reference lines

Figure B.1 - Diagram of the test site and the location of the vehicle with a trailer for recording the dependence of the sound level of tires on time

The measurement of the dependence of the sound level on time begins with the definition of lines A" - A" and B" - B" as shown in Figure B.1. These lines are defined with lead distance d t from trailer wheel axles to the reference point of the traction TS(See figure B.1.). Reference point is a point TS, at the intersection of which the lines A" - A" and B" - B" note beginning and the end registration time sound. When passing as TS with a trailer, and a single traction TS use the same registration method sound level.

B.3.4.2. Additional measurements

During each pass, the following information is recorded:

a) ambient air temperature;

b) path surface temperature;

c) whether the wind speed exceeds 5 m/s (yes/no);

d) whether the difference between the measured and background noise levels is 10 dBA or more (yes/no);

e) the average speed of passage of the traction TS between lines A - A and B - B.

B.3.5. Average sound levels

Record changes over time in sound levels and the maximum level reached during each pass for each microphone. Continue measuring until the five maximum sound levels recorded for each speed of movement and for each microphone position differ by more than ± 0,5 dBA from their uncorrected mean values. In accordance with 7.2, these average maximum levels and average time-dependence levels must be corrected for temperature. The temperature-corrected values ​​obtained for both microphones are then averaged to determine microphone-averaged sound levels and time dependence. Next, calculate the arithmetic mean of the two sound levels averaged over the microphones for traction vehicle alone and together with a trailer and record the average sound level of the passage. Apply the same averaging technique for the sound level vs. time. The following calculations use the following average values ​​for the dependence of the sound level on time:

`L T - average value of maximum sound levels traction TS without trailer;

L T (t) - the average value of the time dependence of sound levels traction TS without trailer;

`L Tp is the average value of the maximum sound levels in the test passage (traction TS with a trailer)

L Tр (t) - the average value of the time dependence of sound levels in the test passage (traction TS along with the trailer).

B.3.6. Synchronizing Time Dependency Records

When crossing the traction TS lines O" - O" along with the sound level, a synchronizing pulse must be registered. This pulse should be used to accurately align signals in time for averaging and subtracting. levels.

B.3.7. Test Method

The methodology for testing with a trailer consists of the following steps.

a) Preparation

1) Establish a reference point on the towing TS for time synchronization.

2) Measure dt(see figure B.1).

3) Determine the position of the lines E" - E", A" - A", O" - O", B" - B" and F" - F" on the course test site as shown in Figure B.1. Set the record timing devices so that sound level recording starts on the line E" - E" and ended on the line F" - F".

4) Average speed between lanes A - A and B - B should be equal to (80 ± 1.0) km/h for tires of classes C1 and C2 and (70 ± 1.0) km/h for tires of class C3. The speed is measured from A - A before B - B, which is for the timing sensor on the towing TC is equivalent to a plot from A" - A" before B" - B".

5) Install the data recorder in such a way that the recording of sound level values ​​sequential in time is carried out in the area from the lines E" - E" up to the lines F" - F" both in single and joint tests with a trailer. Install a sensor for synchronization of time sequences of sound levels relative to the line O" - O" in accordance with B.3.6.

6) Check instruments for measuring air temperature and wind speed.

b) Single test (tractive vehicle without trailer) at least five passes

1) Record the maximum sound level and the change in sound level over time in each pass and for each microphone position. Continue these measurements until the maximum sound level at each measurement point differs by more than ± 0,5 dBA from their mean value.

4) Perform steps 1) to 3) from the beginning to the end of each test series. Traction test TS shall be carried out each time the air temperature during the test changes by 5 °C or more.

c) Combined test (tractive vehicle with trailer) at least five passes

1) Record the maximum sound level and the change in sound level over time in each pass and for each microphone position. Continue these measurements until the maximum sound level differs by more than ± 0,5 dBA from their mean value at each measurement point.

2) Temperature-correct five sound levels versus time and maximum sound levels within ± 0.5 dBA of their mean value.

3) For these five sound levels versus time, an average sound level is calculated.

See tables B.1 and B.2.

AT 4. Determining Tire Sound Levels

B.4.1. Accounting for the influence of traction vehicle noise

Before determining the level of tire noise during coasting, it is necessary to make sure that the corresponding calculations are possible. For a correct calculation of the tire noise level, there must be a sufficient difference between the sound levels measured for a single TS, and sound levels TS with a trailer. This difference can be checked in two ways.

a) The difference between the maximum sound levels is not less than 10 dBA

If for both measurement points the difference in the average value of the sound levels TS together with a trailer and the average value of the maximum sound levels of a single traction TS is at least 10 dBA, effective measurements can be taken. It is assumed that all other requirements regarding ambient conditions, background noise, etc. are met. In this special case, the tire noise level is equal to the average of the maximum level measured for TS with trailer:

L tire = `L Tr,

where L tire - sound level of the tire itself (i.e. the value to be determined), dBA.

b) The difference between the maximum sound levels is less than 10 dBA

If the difference between the average sound levels TS together with a trailer and the average value of the maximum sound levels of a single traction TS for both or one measurement point less than 10 dBA, then further calculations are needed. These calculations use corrected averages of sound levels versus time.

B.4.2. Calculations based on the dependences of sound levels on time

To be determined sound level tires is the difference between the average sound levels TS with trailer and single traction TS. To calculate this difference, the temperature-corrected average of the sound level versus time is subtracted from that for TS with a trailer. Five-pass average sound levels where the maximum sound levels differ by less than ± 0.5 dBA are calculated as described above. An example of sound levels versus time is shown in Figure B.2.

1 - traction TS; 2 - TS with a trailer

Figure B.2 — Sound levels versus time during coasting for the trailer test method

After bringing the dependences on time to the origin relative to the line O" - O", the main parameter for analysis is the difference between the average dependence of the level on time for the traction TS together with the trailer and the average dependence of the level on the time of the single TS at the same point. This level difference L Tr - L T is shown in Figure B.2.

If this difference is not less than 10 dBA, then the levels measured for the traction TS with a trailer, are valid values ​​for the test tire; if this difference is less than 10 dBA, then the tire sound level is calculated by logarithmic subtraction of the sound level value for a single TS from the value for TS with a trailer as shown below. The logarithmic difference is expressed in terms of the above and shown in Figure B.2, the mean values ​​of the time dependences. Tire sound level to be determined L tire , dBA, is calculated by the formula

where L T p - maximum sound level, dBA for the test pass ( TS with a trailer)

L T - traction sound level TS without trailer, dBA obtained for the same position TS, which is L Tr.

B.4.3. Method for determining the sound level

If the average value of the maximum sound levels for the traction TS with a trailer for the right and left microphones exceeds the equivalent level for a single TS by at least 10 dBA, then the sound level of the tire is equal to the sound level TS with a trailer (calculation results are given in Table B.5) and therefore the procedures a), b) and c) below are not followed. However, if this difference is less than 10 dBA, then the following procedures are performed:

a) Align the beginnings of the recording dependence of sound levels on time for a single TS and TS together with the trailer and determine the arithmetic level difference for each time increment. Record this difference in sound levels at the point of maximum level for TS with a trailer. Repeat this action for each set of test passes.

If the registered difference exceeds 10 dBA, then the sound levels of the tires are equal to the sound levels TS with a trailer.

b) If the calculated difference is less than 10 dBA and more than 3 dBA, then the tire sound level is determined as the logarithmic difference between the maximum value of the sound level versus time for traction TS with a trailer and the average value of the dependence of the sound level on the time of a single TS at the point in time corresponding to the maximum sound level for TS with a trailer.

c) If the calculated difference is less than 3 dBA, the test results are considered unsatisfactory. Sound level TS must be reduced to such a value that the indicated difference becomes more than 3 dBA, which is necessary for the correct calculation of the tire sound level value.

See tables B.1 and B.2.

B.5. Test report

The test report must include the following information:

b) meteorological conditions, including air and test site surface temperatures for each pass;

c) an indication of when and how the surface of the test site was checked for compliance with the requirements of GOST R 41.51;

d) the width of the rim of the tire under test;

e) tire data, including manufacturer's name, trademark, trade name, size, LI or load capacity, speed category, pressure rating and tire serial number;

f) type and group of test TS, model year and modification information (design changes) TC regarding its noise characteristics;

g) a description of the test fixtures, specifying the length of the hitch, camber and toe-in data under test load;

h) the tire load in kilograms and in percent LI for each tire tested;

i) air pressure in kilopascals (kPa) for each test tire (when cold);

j) the speed at which TS moves past the microphone on each pass;

k) the maximum value of the sound levels for each coast-down for each microphone;

l) maximum sound level, in dBA, normalized to the reference speed and corrected for temperature to the nearest decimal place.

Tables B.1 and B.2 provide forms for reporting test results and recording additional data regarding tire noise tests. Tables B.3, B.4, B.5, B.6 and B.7 respectively give examples of recording the results of traction tests. TS, TS with a trailer, validation of test results, verification of calculations for time dependence, sound level difference and calculation of tire sound level.

Table B.1 - Test report

Test to determine the noise level from the contact of tires with the road surface when coasting in accordance with GOST R 52800-2007 (ISO 13325:2003)
Test report number: ________________________________________________________________
Tire data (trademark, trade mark, manufacturer): ___________________________________ __________________________________________________________________________________________
Manufacturer's data for the commercial use of tires: _____________________________________ __________________________________________________________________________________________ __________________________________________________________________________________________
Manufacturer's address: _______________________________________________________________ __________________________________________________________________________________________
Tire Size: _______________________________ Serial No. _________________________________
Nominal pressure: ___________________
Tire class: (check one box)	Passenger car (C1)
	Truck (C2)
	Truck (C3)
Annexes to this protocol: _______________________________________________________________ __________________________________________________________________________________________
Sound level dBA at reference speed:

(GOST 16504-81, GOST R 54783-2011)

1. Preliminary - tests prototypes products in order to determine the possibility of their presentation for acceptance testing.

2. Acceptance - testing of prototypes, carried out accordingly in order to resolve the issue of the advisability of putting these products into production.

3. Periodic - tests of manufactured products, carried out in the volumes and within the time limits established by the regulatory and technical documentation, in order to control the stability of product quality and the possibility of continuing its production.

4. Qualification - tests of the pilot series or the first industrial batch, carried out in order to assess the readiness of the enterprise to produce products of this type in a given volume.

5. Typical - tests of manufactured products, carried out in order to assess the effectiveness and feasibility of changes made to the design, recipe or technological process.

6. Certification - tests of products carried out in order to establish the compliance of the characteristics of its properties with national and (or) international regulatory documents.

7. Tests of foreign equipment in order to determine the fit into the technology and the complex of machines for the production of crops and compliance with domestic requirements in terms of destination.

8. Testing of petroleum products in order to determine the quality of fuels and lubricants used in the agro-industrial complex.

9. Surveys of new agricultural machinery of domestic and foreign production in the conditions of real operation in order to check the quality of manufacture and technical reliability by the method of inspection and questioning service personnel and engineering and technical workers.

List of documentation required for testing a prototype

(GOST R 54784-2011; GOST 28305-89)

Operational documentation submitted with the machine:

1. Technical description and operating instructions (operating manual)

2. Passport or draft passport (if available).

3. Catalog of parts and assembly units (if available)

4. For machines working with pesticides and mineral fertilizers:

5. “Safety rules for the storage, transportation and use of pesticides in agriculture.

Operational documents for the construction, content, presentation and design must comply with GOST 2.601-2013, GOST 27388-87.

List of documentation additionally (if necessary) submitted with the machine

1. Terms of Reference or ND replacing it.

2. Draft specifications (TU - if available).

3. Protocol of preliminary (factory) tests.

4. List of changes made to the design of the machine compared to the previously tested sample(s).

5. A set of assembly drawings and its components (assemblies).

a. mounting - electric, hydraulic and pneumatic;

b. fundamental - technological, kinematic, electrical.

7. Maps of micro footage of the main wear parts (at the request of the testing organization).

8. Draft factory selling price, limit, parity price at the time of testing.

9. Draft temporary annual consumption rates for spare parts.

10. List of tools and equipment for maintenance.

Shipping documentation to be submitted with the machine:

1. Picking list.

2. Packing lists (sheet).

List of documentation required for testing a serial sample (OST 10 2.1-97; GOST 28305-89)

1. Passport.

2. Specifications.

3. Technical description and instructions for operation, maintenance, installation, start-up, adjustment and running-in of the product at the place of its use in accordance with GOST 27388.

4. Measures to eliminate the shortcomings previously identified during testing and economic verification.

5. List of structural and technological changes, drawings of modified assembly units and parts with an explanatory note.

6. Draft factory selling price, limit, parity price of the product at the time of testing.

At the request of the testing organization, the enterprise that submitted the product for testing must submit a catalog of parts and assembly units in accordance with GOST 2.602, drawings for any parts.

List of documentation required for the Certification Body:

1. Declaration-application for certification of products in the GOST certification system (Appendix 1).

2. Specifications for manufacturing.

3. Manual (instruction) for operation.

4. List of documentation required for carrying out certification tests:

5. Decision of the Certification Body on the declaration-application for certification of products (machines) (Appendix 2).

6. Act of sampling for certification tests (selection is made in accordance with GOST 18321 and the rules of the "Agricultural machinery certification system") (Appendix 3).

7. Specifications for manufacturing.

8. Manual (instruction) for operation.

9. Passport for the car.

10. A list of changes made to the design of the machine and to the design and operational documentation, compared with the previously tested sample (s) and (or) in the process of testing.

Added to site:

Approval date:

GENERAL REQUIREMENTS

GOST 28697-90

USSR STATE COMMITTEE FOR PRODUCT QUALITY MANAGEMENT AND STANDARDS

Moscow

STATE STANDARD OF THE UNION OF THE SSR

PROGRAM AND METHODOLOGY FOR TESTING BELLOWS COMPENSATORS AND SEALS Generalrequirements Program and test methods of bellows compensators and seals. General requirements

GOST 28697-90

Date of introduction 01.01.92

This standard applies to the program and method of control tests of bellows expansion joints and metal seals carried out at the stages of their development and production.

The standard establishes general requirements, the necessary types of tests, the sequence, rules and conditions for their implementation, as well as the procedure for reporting the results.

The standard does not apply to preliminary and type tests, which must be carried out according to special programs.

The terms and definitions used in this standard are given in annex 1.

The provisions of this standard are mandatory.

1. TEST REQUIREMENTS

1.1. In the process of creating bellows metal expansion joints and seals (hereinafter referred to as SC and UE), as well as their production, in the general case, acceptance, qualification, acceptance and periodic tests should be carried out.

Arbitration tests are also carried out according to this standard. The definition of arbitration tests and the procedure for organizing their conduct are given in clause 1.5.

1.2. According to the level of acceptance tests, they can be: state, interdepartmental, departmental.

Acceptance tests are carried out by acceptance committees appointed by order of the head of the developer. State acceptance commissions are appointed by the ministry (department) - product developer.

1.3. Acceptance tests are not carried out in the following cases:

1) modernization of products through changes made to the design of the product, its material design or manufacturing process;

2) creating a size range based on a product previously put into production or expanding an existing size range with one or more products that differ in nominal bore (Dy) and (or) nominal pressure (Py)

Notes:

1. According to listing 1, type tests of this product are assigned in the prescribed manner.

2. According to listing 2, it is allowed to carry out acceptance tests newly developed standard sizes SK and UP, which is stipulated in the terms of reference for their development.

1.4. Qualification tests are not carried out:

1) in the manufacture of prototypes for acceptance testing by an enterprise designated as a manufacturer of these products;

2) in the manufacture of product samples for type tests the manufacturer of this product.

1.5. Arbitration tests (examinations) are carried out on samples of specific products, the need for an objective assessment of the quality of which is determined in the prescribed manner by arbitration, law enforcement or state supervision bodies. Tests (examinations) are carried out by the head organization for state testing of products of this type (hereinafter referred to as GOGIP), which issues a conclusion based on their results with the attached test reports to the interested body (bodies).

1.6. Acceptance, qualification, periodic and arbitration tests are carried out on samples of single products or on typical representatives of groups of homogeneous products (controlled batches of products).

1.7. The procedure for the formation of groups of homogeneous products and sampling for testing is established by the industry normative and technical documentation (hereinafter referred to as NTD) in agreement with the representative of the customer (main consumer), and, if necessary, with the representative of the state supervision body.

Note. Selection of product samples for testing from among typical representatives (controlled batches) is carried out by a single sampling method, taking into account the requirements of GOST 18321.

1.8. In the general case, products (SC, UE) are considered homogeneous if they are characterized by:

1) commonality of constructive and technological solution, which in this case means single design bellows and a single technological process for the manufacture of this group of products;

2) the same material design of the main components of the products (bellows, connecting fittings);

3) commonality of functional purpose, which is understood as the ability to provide movement of the same type: axial movement, shear, angular movement (rotation) or their combinations, regardless of the types of products.

Notes:

1. Big changes product designs within the standard range (according to Dy, Ru) are not signs of heterogeneity.

2. In the general case, a group of homogeneous products can be made up of several single products, a standard size range of products, or several standard size ranges.

1.9. Tests should be carried out in the manner prescribed by Appendix 2; the procedure for drawing up, submitting and approving documents based on test results is given in Appendix 3.

Standard forms of acts of acceptance commissions are given in appendices 4, 5.

1.10. By the beginning of the acceptance tests, the production personnel of the enterprise - the manufacturer of the SC, UE must check:

1) compliance of the technological process of manufacturing products with the requirements of technological documentation in force at the time of the start of testing;

2) the completeness of the step-by-step control performed in the process of manufacturing products;

3) compliance of products with the requirements of design documentation, including basic dimensions, strength and tightness tests, appearance and marking;

4) serviceability of test equipment and measuring instruments.

1.11. By the beginning of the acceptance, qualification, periodic and arbitration tests of products, preparatory measures must be completed, providing for:

1) certification of the test unit;

2) logistical and metrological support of tests;

3) production of prototypes or product samples (typical representatives) and their acceptance by the technical control service of the manufacturer;

4) the appointment of an acceptance committee and the creation of the necessary conditions for its work - when conducting acceptance tests;

5) appointment of a responsible deliverer of tested prototypes of products - during acceptance tests;

6) appointment of a person responsible for conducting qualification, periodic and other tests of products;

7) preparation of documentation in accordance with Table. 1 and technological equipment necessary for testing.

Table 1

Documents submitted for testing	Test types
	acceptance	qualifying	acceptance	periodicals and others
Terms of reference for the development of SC (UE) and all additions to it (if any)
Project NTD for products
NTD for products
Materials of preliminary tests (if any)
Acceptance test report
CD set
TD set
Typical (or private) program and test method (if developed)
Map of technical level and product quality according to GOST 2.116
Passport (passports) for product samples or typical representatives of a group of homogeneous products with a mark of verification or acceptance by the technical control service
In-process acceptance materials in the manufacturing process
The act of sampling for testing
Documents confirming the compliance of the materials used with the normative and technical documents for the material
Documents confirming the certification of test benches and verification of measuring instruments
Test materials of the parent organization for state testing *
Order (decision) on the appointment of the acceptance committee
Order (instruction) on the appointment of a responsible deliverer
Order (instruction) on the appointment of a person responsible for testing

* GOGIP transfers test materials, test reports and conclusions to the disposal of the acceptance committee at its request.

Notes:

1. The “+” sign means that the document is being submitted, the “-” sign means that the document is not being submitted.

2. At the request of the acceptance committee, other documents must also be submitted, if their development is provided for by the TOR - for acceptance tests.

1.12. The appointment of a person responsible for conducting qualification, periodic and other tests of products should be carried out by order (instruction) of the head of the manufacturer.

The appointment of a responsible deliverer should be carried out by order (instruction) of the head of the enterprise conducting the tests.

1.13. Tests should be carried out in closed heated rooms at ambient temperature (293 ± 10) K ((20 ± 10) °С).

1.14. The test equipment must be certified in accordance with GOST 24555, and the measuring instruments must be verified.

1.15. Tests should be carried out using simulators of working media (drinking water, atmospheric air), if the use of a specific test medium is not specified in the technical documentation for this product.

2. TEST PROGRAM

2.1. Test object

2.1.1. The object of the test are:

1) prototypes of single products or samples - typical representatives of groups of homogeneous products (hereinafter - prototypes) - during acceptance tests;

2) samples of single products or samples - typical representatives of groups of homogeneous products, mastered by this enterprise for the first time (hereinafter - samples of mastered products) - during qualification tests;

3) samples of single products or samples - typical representatives of groups of homogeneous products manufactured by this enterprise (hereinafter - samples of products) - during periodic testing of finished products;

4) samples of products according to listings 1-3, planned for export;

5) manufactured products in the volume of manufactured batches - during acceptance tests;

6) samples of specific products, for which, in the prescribed manner, must be carried out independent evaluation quality, - in arbitration and other types of control tests (examinations).

2.1.2. Acceptance testing should be carried out on each batch of products.

2.1.3. Tests of all types (except for acceptance tests) are subjected to at least two samples of each single product, a specific product (size) or a typical representative of a group of homogeneous products. On each sample, the index "I" is applied, which means that the product belongs to the tests. The number of samples to be tested must correspond to that specified in the NTD for this product.

2.2. Controlled parameters and characteristics

2.2.1. In the general case, the composition of the tests and the sequence of checks should correspond to those indicated in Table. 2, if other tests are not provided for by the regulatory and technical documentation for this product. If it is necessary to carry out additional checks, private (working) programs and test procedures should be developed that take into account the requirements of this standard and agreed in the prescribed manner with the customer (main consumer).

table 2

Checked parameters and characteristics	Test types
	acceptance	qualifying	acceptance	periodicals and others
Strength
Heat resistance
tightness
Basic dimensions and markings
Appearance
Rigidity and amplitudes of static displacements
Vibration resistance
impact resistance
Probability of uptime
tightness

Note. The sign "+" means that the tests are being carried out, the sign "-" means that they are not being carried out.

2.2.2. Tests according to table. 2 subject all samples presented for testing.

2.3. Conditions and procedure for testing

2.3.1. Strength tests of SC and UE are carried out by test hydraulic pressure of the test medium, the value of which for a given conditional pressure Ru is established by GOST 356, unless other standards are provided for by the NTD for these products.

During testing, the products must be protected from stretching (compression).

Note. It is allowed to carry out tests at the pressure of the test medium Pisp = Ru if it is provided for by the technical documentation for this product. The test medium is water.

2.3.2. Heat resistance tests are subject to SC and UE, intended for operation in working media with a temperature of more than 423 K (150 °C).

Tests are carried out by control heating of products in a preheated furnace to a temperature of (548 ± 25) K ((275 ± 25) °C).

Note. Products, the design of which contains a guide pipe, are subjected to a heat resistance test before installation of the pipe.

2.3.3. Tightness tests are carried out in accordance with paragraph 2.3.11.

2.3.4. The main dimensions of the SC and UE are controlled by a measuring tool of the second accuracy class by comparing the actual values ​​with the dimensions established by the design documentation.

Product labeling is checked visually.

2.3.5. The appearance of the SC and UE is checked by inspection for the absence of damage and defects in structural elements. During inspection, the quality of the surface of the bellows and the connecting surfaces of the flanges should be checked.

2.3.6. Determination of stiffness - axial (Cl), shear (Cd) angular (rotation, Cg) should be carried out at atmospheric pressure test environment within the displacement amplitudes (l, d, g) established by the NTD for this product. The test medium is air.

2.3.7. The displacement amplitudes (static) l, g, d, established by the NTD for this product (the NTD project), are controlled in the process of determining the stiffness (Cl, Cg, Cd) in accordance with clause 2.3.6.

2.3.8. Vibration tests should be carried out in the axial and transverse directions at atmospheric pressure. The test medium is air.

The frequency range and permissible vibration acceleration are accepted in accordance with the requirements of the NTD for this product.

2.3.9. Impact tests should be carried out in axial and transverse directions at atmospheric pressure of the test medium.

Characteristics of impact loads in terms of acceleration, pulse duration, number of impacts are established by the NTD for products.

Note. Depending on the design features of the products, their weight and overall dimensions verification of SC and UE for the ability to withstand the destructive effect of shock loads is allowed to be carried out by simulating the impact of impact by other types of loading, equivalent to it in terms of the level of stresses in the structure caused by impact.

2.3.10. Tests to confirm the probability of no-failure operation (hereinafter referred to as PBR) of SC and CP should be carried out for the designated operating time, with amplitudes of repeated static movements and the effect of test internal (external) hydraulic pressure Pisp = Ru, established by the technical documentation for products. The test medium is water.

Notes:

1. The value of WBR for newly developed products must be determined in preliminary tests - if they are carried out. In the event that preliminary tests are not carried out, the determination of the WBF is carried out during acceptance tests.

2. Determination of the WBR should be carried out experimentally or taking into account additional information about the testing of analogues (or the main elements of the SC, UE) according to the regulatory and technical documentation in force in the industry - product developer.

2.3.10.1. FBG is confirmed by test operating time with the number of failures equal to zero.

2.3.10.2. When exposed to several types of displacements (loads) on the SC and UE, tests should be carried out in one equivalent mode, corresponding in terms of damaging effect to the totality of operational loads (loading modes).

The parameters of the equivalent test mode are determined by the developer of the SC and UE by calculation according to the methods in force in the industry, and the calculation itself is attached to the test materials (if these parameters are not specified in the technical documentation for this product).

2.3.11. Tightness tests should be carried out during the acceptance testing of products, as well as after testing according to paragraphs. 2.3.8, 2.3.9 and 2.3.10.

The threshold sensitivity of the tightness control system, as well as the level (class) of tightness of products is set depending on the operating conditions of the technical documentation for products.

2.3.12. Weight control should be carried out by weighing the samples presented for testing.

2.4. Requirements for metrological support of tests

2.4.1. Logistical and metrological support of tests is carried out by the enterprise conducting the tests.

2.4.2. The necessary measuring instruments (instruments and devices) are assigned taking into account the measurement errors of controlled quantities established by the technical documentation for products, from among those permitted for use.

2.4.3. A typical list of types of instruments and devices used when checking the parameters and characteristics of the SC and UE is given in Appendix 6.

A specific list of materials, measuring instruments and registration should be given in private (working) test procedures.

2.5. Work safety requirements

2.5.1. Safety and accident-free testing is ensured by the enterprise where the tests are carried out, in accordance with the requirements in force in the industry.

2.5.2. Test benches must be provided with fences and warning signs in accordance with GOST 12.4.026 with an explanatory inscription: “CAUTION! TESTING ON!

2.5.3. In the event of an emergency, the tests should be immediately terminated, the stand and equipment de-energized. The resumption of testing is allowed only after the elimination of the causes that caused the emergency.

2.5.4. All testing work is carried out by suitably trained personnel under the direction of the responsible supplier or person responsible for testing.

2.5.5. Moving objects weighing more than 20 kg must be carried out using lifting equipment.

3. TEST PROCEDURE

3.1. Depending on the composition of the test equipment and measuring instruments, private (working) test methods should be developed on the basis of this standard.

3.2. Acceptance test methodology

3.2.1. The strength test should be subjected to assembled products, without protective covers. Products must be cleaned of foreign objects; the presence of paint coatings on the connecting surfaces and bellows is not allowed.

3.2.2. The process of loading the SC and UE with pressure is carried out sequentially stepwise, with holding every 0.1 Risp (but not less than 0.05 MPa (0.5 kgf/cm2)), for 1-2 minutes. In all cases, it is not allowed to load the product with a pressure exceeding the value of the test pressure Ppr, as well as the value of the conditional pressure Ru during tests according to clause 2.3.10.

3.2.3. SC and UE are considered to have passed the tests if, under the test pressure load Ppr, no pressure drop was observed for 5 minutes, and after the load was reduced from the test pressure value to the conditional Рy, no loss of axial stability was observed.

3.2.4. Thermal stability control is carried out visually after heating the products for 1 hour in a preheated furnace. Visible delamination, swelling, cracks and breaks on the inner and outer surfaces of the bellows and welds are not allowed.

3.2.5. Tightness control should be carried out in accordance with the requirements of clause 3.7.

3.2.6. Dimensional control and marking check should be carried out on a calibration plate in a room with general and local lighting that meets the established standards for machine-building shops.

The accuracy of dimensional control is due to the limit deviations specified by the design documentation.

3.2.7. The control appearance should be carried out under the conditions specified in clause 3.2.6. The surfaces of the bellows and the connecting surfaces of the flanges are checked by comparison with a control sample of the acceptable surface condition (control samples). Control samples for the connecting surfaces of the SC and UE and the surface of the corrugated part of the bellows must be made by the manufacturer of the product, agreed with the developer and approved in the prescribed manner.

Damage to the structural elements of the SC and UE, as well as defects on the surfaces of the bellows and the connecting surfaces of the flanges, greater than those of the control samples, are not allowed.

3.3. Method for determining (checking) stiffness and amplitudes of static displacements

3.3.1. Determination of axial stiffness Сl in compression-tension

3.3.1.1. The bellows compensator or seal (test sample) is installed on the stand in accordance with Appendix 7, drawing. 12.

The center of application of the force that provides movement is aligned with the center of the product (axis of symmetry). The permissible deviation is set in accordance with the technical documentation for the test equipment (bench).

3.3.1.2. A test force is applied to the sample, which ensures compression (tension), and the correct installation of the product on the stand is checked.

The installation is considered correct if the movement of the free end of the product during compression (tension) occurs without distortion. Permissible deviations should not exceed the value of the tolerance for parallelism of the end surfaces of the product, established by the design documentation for the SC (UP).

3.3.1.3. Similarly to clause 3.3.1.2, an axial force is applied to the product, which provides compression (stretching) of the SC (UP) bellows by the value of the amplitude of the axial stroke specified in the technical documentation for this product. Compression (stretching) is carried out stepwise, through brine intervals, up to 3-5 points. At the same time, at each point (i), the value of the current displacement liszh(rast) is fixed along the indicator and the applied force Qiszh(rasts) - according to the dynamometer.

3.3.1.4. Measurements according to clause 3.3.1.3 are performed 3 times, after which the average values ​​of the applied force Qcicompress (growth) are determined at each i-th point.

According to the average values ​​of the applied forces Qci, the numerical values ​​​​of the stiffness () kN / m are determined, for any fixed value of the displacement according to the formula

.

Note. When determining the value of the force Qci, the additional influence of the mass of the connecting fitting DQ must be excluded:

Qiszh \u003d Qi + DQ,

Qi rast = Qi - DQ.

3.3.2. Determination of the angular stiffness Cg during rotation (bending) of the SC and UE

3.3.2.1. A sample of the rotary type SC is installed on the stand in accordance with Appendix 7, fig. 3.

In the test system for measuring the values ​​of the angular travel (rotation) at the free side of the sample, a lever must be installed on the connecting fitting SC, which creates a bending moment Mizg, and an optical quadrant, which fixes the angle of rotation. The turning force on the value of the amplitude established by the technical documentation for this product, at equal intervals at 3-5 points, should be measured with a dynamometer.

3.3.2.2. The average stiffness value is determined in the order given in paragraph 3.3.1.4.

According to the average values ​​of the efforts Qci izg, the numerical values ​​​​of the stiffness Сg i, kN-m / deg, are determined at any fixed value of the angle of rotation (at the i-th point) according to the formula

where Mizg is the bending moment created by the force Qci izg at the current point i on the shoulder l kN-m;

Mizg.i = Qci izg.l.

3.3.2.3. Determination of the angular rigidity of universal SC, as well as UE, is carried out by a method similar to that specified in paragraphs. 3.3.2.1, 3.3.2.2, in accordance with Appendix 7, fig. 4.

The swivel assembly of the technological equipment provides rotation (bending) of the corrugated shell relative to the center of rotation of the product.

Note. When determining the numerical values ​​of the rigidity of the SC (FC) in this case, the force created by friction in the hinged joints of the tooling should be excluded from the measurement results obtained.

3.3.3. Determination of stiffness Сd at shear of SC and UE

3.3.3.1. The bellows compensator or seal is installed on the stand in accordance with Appendix 7, drawing. 5.

3.3.3.2. A dynamometer must be installed in the test system to measure the force, and an indicator to measure the displacement (shear) value.

Shear-type products are tested in the state of delivery, and universal-type and shear-rotary products are tested using special technological equipment.

3.3.3.3. To the sample SC (UP) from the side of the movable end in the direction perpendicular to the axis of the product, apply a shear force Qshdv, measured by a dynamometer.

The movement (shift di) is carried out in steps, at equal intervals of 3-5 points, up to the amplitude value specified in the NTD for this product.

3.3.3.4. The numerical value of the shear stiffness Cd i, kN/m, is determined by the formula

where Qci shift is the average value of the effort over 3 measurements.

Note. When determining the numerical values ​​of the stiffness of the SC (FC), the stiffness of which is measured using technological equipment, the force created by friction (DQ) in the hinge joints should be excluded.

3.3.4. The displacement amplitudes are checked when determining the corresponding stiffness according to the method given in paragraphs. 3.3.1.3, 3.3.2.1, 3.3.2.3, 3.3.3.

3.4. Vibration Test Method

3.4.1. Depending on the nature of the vibration loads specified in the technical documentation for products, various test methods can be assigned using the appropriate equipment:

1) impact of vibrations in the frequency range from 5 to 60 Hz with amplitudes of vibration acceleration up to 19.6 m/s2, with verification of this impact in the resonant zone of the frequency range;

2) exposure to vibrations in the frequency range from 5 to 2000 Hz with amplitudes of vibration acceleration up to 294 m/s2.

3.4.2. The test system should provide measurement of vibration acceleration amplitudes (m/s2), vibration frequencies (Hz), vibration displacement amplitudes (oscillation spans, mm) and time of exposure to vibration loads on the sample (s, h).

Note. The test equipment must be preliminarily checked in the entire frequency range for the presence of its own resonances, data on which (if any) are entered in the equipment passport (or a document replacing it). The occurrence of resonant vibrations at the natural resonant frequencies of the equipment during testing of the product is not a sign of product resonance.

3.4.3. Testing of product samples - according to clause 3.4.1, listing 1.

3.4.3.1. The product is installed on a vibration stand in accordance with Appendix 7, fig. 6. Tests are carried out under the influence of vibration loads in the axial (hereinafter: along the X axis) and in the transverse (hereinafter: along the Y, Z axes) directions.

The expediency of using special and unloading devices, equipment is determined by the testing department.

3.4.3.2. The product is tested as an assembly, unless other requirements are specified in the NTD for this product.

3.4.3.3. Acceleration sensors should be installed on the fixture and on the product in such a way that their axis coincides with the direction of vibration of the table of the vibration exciter of the stand. The number of sensors placed on the movable table of the vibration exciter of the stand, equipment, product elements depends on the size and design of the product, but should not be less than 4 pcs.

A non-contact method for measuring the vibration displacement amplitudes of the corrugation elements is allowed.

3.4.3.4. Vibration testing consists of the following steps:

1) tests to detect resonant frequencies (resonances);

2) vibration strength tests in a given frequency range;

3) vibration strength tests at resonant frequencies.

3.4.3.5. Resonance detection tests are carried out with a smooth change in the frequency of disturbing oscillations (sinusoidal vibration) in each frequency band within the entire frequency range specified by the technical documentation for this product. The travel time of each frequency band (continuous frequency sweep rate) should be sufficient to detect resonance, but not less than two to three minutes in one direction.

After passing the entire frequency range in the forward direction (from the lower frequency to the upper one), it is re-passed in the opposite direction. A sign of resonance is an increase in the amplitude of vibration displacement (vibration acceleration) of individual parts or structural elements of the product by a factor of two or more compared to the amplitude of vibration displacement (vibration acceleration) of the attachment points measured by sensors installed on the side of the vibration source:

where A is the amplitude of vibration displacement (vibration acceleration) of the points of attachment to the table of the vibration accelerator of the stand, mm (m/s2);

A1 - amplitude of vibration displacement (vibration acceleration) of structural elements of the SC (UP) in the axial direction, mm (m/s2);

A2 - the same, in the transverse direction.

Notes:

1. One or more resonant frequencies can be detected within the entire specified NTD for a given product in the frequency range.

2. The breakdown of a given frequency range into frequency bands is carried out in accordance with the rules established in industry regulatory and technical documents, depending on the design, purpose and scope of the SC and UE, unless other requirements are provided for by the NTD for these products.

3. The difference in amplitudes of vibration displacements (vibration accelerations) at any two points of one element of the product should not be more than 15%.

3.4.3.6. If resonances are not detected during the tests according to clause 3.4.3.5, the products are subjected to vibration strength tests in the frequency range specified in the technical documentation for this product.

The tests are carried out with a smooth change in the frequency of disturbing oscillations and at a speed of its continuous sweep, providing the following test duration:

2 h - for axial impact of vibration loads;

4 h - for transverse impact of vibration loads.

Breaks are allowed during the tests, but the total duration of the tests must be maintained.

3.4.3.7. The sample is considered to have passed the vibration strength test (clause 3.4.3.6) if, after exposure to vibration loads, it has not lost its tightness and no mechanical damage (cracks, destruction) of its elements has been established during visual inspection.

3.4.3.8. If resonances are detected during the tests according to clause 3.4.3.5, the products are subjected to vibration strength tests at the corresponding resonant frequencies and in the positions at which they were detected.

The tests according to clause 3.4.3.6 are not carried out in this case.

3.4.3.9. For products in which resonant vibrations of the same frequency occurred in the axial and transverse directions, the tests according to clause 3.4.3.8 are carried out only in the position in which the vibration displacement (vibration acceleration) amplitude was greater.

The duration of the test (exposure) at each detected resonant frequency is determined from the condition of the product 106 oscillations. The criterion for evaluating the results of tests for vibration strength at resonant frequencies is similar to that specified in clause 3.4.3.7.

3.4.4. Testing of product samples - according to clause 3.4.1, listing 2.

3.4.4.1. The samples are subjected to vibrations similar to paragraphs. 3.4.2, 3.4.3.1-3.4.3.3, in accordance with the vibration impact parameters given in the NTD for this product: type of vibration; frequency range (disaggregated into frequency bands); vibration acceleration; time of exposure to vibration in each frequency band and in the entire range as a whole.

3.4.4.2. The sample is considered to have passed the vibration strength test if, after exposure to vibration loads, it has not lost its tightness and no mechanical damage (cracks, destruction) of its elements has been established during visual inspection.

3.5. Impact Test Method

3.5.1. The bellows compensator or seal assembly is installed on the stand in accordance with Appendix 7, fig. 7. Products intended for operation on liquid media must be filled with a working medium simulator (medium).

The expediency of using special devices, equipment and simulators of boundary conditions is determined by the testing department, based on the design features, overall dimensions and weight of the tested products, if the requirements are not established by the technical documentation for this product.

3.5.2. When installing a sample of SC or UE on the stand, the center of mass of the product (complete with tooling) must be aligned with the axis of action of the shock pulse of the stand. Permissible deviation is set in accordance with the documentation for the test equipment (bench).

3.5.3. Tests are carried out by applying shock loads in the axial and transverse directions specified in the NTD for this product, characterized by:

1) numerical value of impact acceleration (m/s2);

2) pulse duration (ms);

3) the number of impacts.

3.5.4. The acceleration sensor must be installed in the central part of the load table of the stand so that its axis coincides with the direction of impact.

3.5.5. After the impact of each impact, it is necessary to check the fastening of the product on the stand table, as well as to inspect the product for the timely detection of cracks and damage. After the impact tests are completed, the sample is tested for leaks.

3.5.6. Samples of SC and UE, which cannot be tested with the impact of specified shock loads on the stands (due to the large mass, overall dimensions or design features), in agreement with the customer (the main consumer), the developer and the head testing organization, it is allowed to test using simulation of impact other loads (for example, water hammer, static displacement, etc.), provided that they are equivalent to the specified shock loads in terms of the level of stresses arising when they are applied to the bellows shell and restrictive reinforcement elements.

Note. Tests are carried out in accordance with industry methods. Calculations of loading parameters and stress state of the bellows SK (UP) must be attached to the test report.

3.5.7. The sample is considered to have passed the impact resistance test if, after exposure to impact loads (or loads simulating impact), it has not lost its tightness and no damage (cracks and destruction) of its elements has been established during visual inspection.

3.6. Test Method for Probability of Non-Failure Operation

3.6.1. Tests to confirm the FBG with a given confidence probability are carried out on stands that provide the necessary types and amplitudes of movements when exposed to an internal (external) hydraulic pressure equal to Ru.

3.6.2. Depending on the type of SC (UP) and the type of movement established by the program, the assembled products are installed on the stand in accordance with Appendix 7, fig. 8-16.

Note. Protective covers must be removed before testing.

3.6.3. Tests should be carried out at a frequency of movements of not more than 40 cycles per minute. The deviation of the test pressure from that specified by the test program should not exceed 5%.

The test system shall provide:

measuring the pressure of the test medium (MPa) and the value of the displacement amplitude (mm, degree);

registration of the number of accumulated cycles;

the possibility of external inspection of the product during testing.

3.6.4. Confirmation of the TFR should be carried out by test operating time Ni, the numerical value of which should not be less than 1.15 of the numerical value of the assigned operating time Nn with the number of failures equal to zero: Ni ³ 1.15Nn.

Notes:

1. The numerical value of the test operating time Ni is set by the developer of the SC (CP) in the NTD for products by calculation according to the methodology in force in the industry, depending on the initial quantitative indicators (probability of failure-free operation, confidence level, coefficient of variation or the value of the standard deviation adopted the law of distribution of time to failure and the number of samples subjected to testing).

2. When carrying out periodic testing of products used for repair purposes, the confirmation of the WBM must be carried out by a test operating time, the numerical value of which should not be less than the numerical value of the assigned operating time, with the number of failures equal to zero: N and ³ Nн.

3.6.5. The samples are considered to have passed the tests, and the probability of failure-free operation of a batch of manufactured products is confirmed if the samples tested by the operating time N have not lost their tightness and have no mechanical damage.

3.7. Leak test procedure

3.7.1. Tests of SC and UE for tightness should be carried out by mass spectrometric, hydrostatic or bubble methods.

3.7.2. The method (method) of tightness control is established by the design documentation for products, taking into account the provisions and requirements of industry normative and technical documentation, and the threshold sensitivity of the control system is established by the NTD for these products.

3.7.3. In the general case, the following ranges are set for the threshold sensitivity of tightness control systems, depending on the conditional pressure Рu of products:

more than 5-10-2 up to 5, l-µm/rt. st./s - Ru f 1.0 MPa (10 kgf / cm2);

more than 5-10-3 to 5-10-2, l-µm/rt. st./s - Ru St. 1.0 (10) to 4.0 (40) inclusive, MPa (kgf/cm2);

more than 5-10-5 to 5-10-3, l-µm/rt. st./s - Ru > 4.0 MPa (40 kgf / cm2).

3.7.4. It is allowed to apply the following methods of tightness control.

Mass spectrometric method - control methods:

helium or vacuum chamber;

helium probe;

blowing with helium;

hydrostatic method - compression hydraulic method of control;

bubble control method - control methods:

soaping (applying a polymer composition);

compression (immersion in liquid).

Note. Other methods that do not reduce the requirements for tightness and provide a given level of threshold sensitivity of the control system must be agreed with the customer (the main consumer) and the product developer.

3.7.5. When testing SC or UE by methods that provide for the creation of an excess pressure of the test medium inside the product, the samples must be protected from stretching.

3.7.6. The surface of the bellows and welds connecting the bellows to the fittings must be free of rust, oil, emulsion and other contaminants, as well as paint and varnish coatings.

Before checking the tightness of products by the mass spectrometric method, their surface and internal cavities are dried from water and other liquid media. Drying mode (temperature, duration) must be set technological process, and the maximum temperature value should not exceed 423 K (150 °C).

3.7.7. The sample is considered to have passed the tightness test if there was no pressure drop inside the sample, and the penetration of the test medium (control liquid or gas) through the walls of the sample structure (including the connection of its elements) did not exceed the standards established by the design documentation.

3.8. Mass control technique

3.8.1. The control of the mass of SC and UE is carried out by weighing products on a scale. The types of scales should be determined by the technical documentation for products, depending on the scope of the products, their overall dimensions, nominal values ​​of the mass and its permissible deviations.

3.8.2. Only dry samples are subject to weighing, with previously separated transportation and assembly fixtures and devices that are not included in the design of the product during its operation.

3.8.3. When weighing, the controlled product must be installed on the scale platform in such a way that the center of mass of the product along the vertical axis relatively coincides with the center of the scale platform.

3.8.4. The results of mass control of samples of mass-produced products are considered positive if the actual value of the mass of products meets the requirements of the NTD for this product.

4. PROCEDURE FOR PROCESSING AND REGISTRATION OF TEST RESULTS

4.1. Processing of test data

4.1.1. The processing of test data consists in carrying out calculations and calculations, as well as in analyzing and comparing the obtained values ​​of parameters and characteristics with their values ​​specified in the technical documentation for this product, taking into account limit deviations.

4.1.2. The processing of test data should be carried out by the personnel of the testing departments.

4.2. Registration of test results

4.2.1. According to the results of tests (checks), test reports (checks) are drawn up. A separate protocol is drawn up for each controlled parameter or characteristic.

Note. It is allowed to draw up one protocol for registration of the results of several tests (checks).

4.2.2. Test reports should generally include:

1) type of tests (in accordance with Table 2) - in the heading of the protocol;

2) name, symbol and designation of products;

3) serial numbers of the tested samples;

4) the name of the enterprise - the manufacturer of the samples;

5) date of drawing up the protocol;

6) controlled parameters and characteristics;

7) place of testing (name of the enterprise or organization that conducted the tests);

8) reference designation of bench equipment;

9) designation of the document (programs, methods, programs and methods), in accordance with which the tests were carried out;

10) the period of time during which the tests were carried out;

11) test data, including: test conditions and modes; data of the current measurement of parameters (if necessary) and the values ​​of the measured quantities at the control points of measurements; the resulting final values ​​of controlled parameters and characteristics, etc.;

12) information on the results of visual inspection of the samples during the tests and after their completion, indicating the location and nature of the detected damage, destruction;

13) results of weighing (weight control) of samples;

14) results of measurement of stiffness characteristics;

15) the results of the vibration strength test in the form of a conclusion: “passed the test” or “did not pass the test as a result ...”;

16) the results of testing samples for impact resistance in the form of a conclusion: “passed the tests” or “did not pass the tests as a result ...”;

17) sample test data (test time N and; presence or absence of failed samples; number of failed samples (if any) and the number of cycles they have worked by the time of failure) and test results to verify (confirm) the probability of no-failure operation (PBR) in the form of a conclusion on the compliance of samples with the requirements of the NTD for these products in terms of reliability;

18) the results of testing samples for tightness in the form of a conclusion: “The tests passed” or “The tests did not pass as a result ...”, indicating the control method and information about the threshold sensitivity of the control system;

19) comments on the design documentation, draft NTD for products and a conclusion on the technical level and quality of products (for prototypes).

4.2.3. In general, test reports must be accompanied by:

1) tabular and (or) graphic material for determining stiffness;

2) calculations of loading parameters and stresses in the bellows - when simulating a shock load (in the absence of them in the technical documentation for this product);

3) calculation of equivalent test modes when checking the probability of no-failure operation (in case of absence in the NTD for this product);

4) calculation of the numerical value of the test operating time Ni (with the number of failures equal to zero) for tests to check the FBG (in the absence of an indication in the NTD for this product);

5) photographs of damage (if any) caused by exposure to vibration, shock and (or) cyclic loads.

Note. The photographs are completed as a separate attachment to the test materials.

4.2.4. Protocols of interdepartmental and departmental acceptance tests are signed by the head of the testing unit and members (member) of the commission.

4.2.5. The protocols of state acceptance tests conducted by GOGIP or its basic testing divisions are signed by the head of the testing division.

4.2.6. Protocols of qualification, periodic and other types of tests are signed by: the head of the testing unit; person responsible for testing; representative of the customer* (main consumer) and the state supervision authority, if necessary.

* The representative of the customer at the enterprise that conducted the tests.

4.2.7. Each test report must have a designation containing: the conditional code of the enterprise that conducted the tests (four-digit letter code included in the structure of designations of design documentation in accordance with GOST 2.201); the last two digits of the year in which this protocol was drawn up; serial number of the protocol (in the year of its compilation).

Test report designation structure:

Example. YANSH.91.011

4.2.8. The rules for drawing up protocols and other test documents must comply with those set out in Appendix 3, clause 2.6.

The procedure for accounting, storage and circulation of test documents is given in Appendix 8.

APPENDIX 1

Reference

TERMS USED IN THIS STANDARD AND EXPLANATIONS TO THEM

Table 3

	Explanation
Tests	According to GOST 16504
Scope of testing
Test object
Test sample
Prototype
Test Data
Test results
Test report
Test program
Test Method
Test conditions
Test equipment
Control tests
State tests
Interdepartmental testing
Departmental tests
Acceptance tests
Qualification tests
Acceptance tests
Periodic testing
Preliminary tests
Type tests
Head organization for state testing of products
Test division
Basic test unit of the parent organization
Controlled batch of products	A batch of a product of a specific size, which is subjected to control (tests) or from which samples are taken for testing
Typical representative of a group of homogeneous products	A specific product size selected (assigned) from a given group of homogeneous products, the test results of which apply to the entire group of homogeneous products
Bellows expansion joint	According to GOST 25756
Bellows seal
Types of SC (UP)
restrictive reinforcement
Connecting fittings
Parameters and technical characteristics of SK, UP:	According to GOST 25756
hardness, including
axial stiffness (Cl)
angular stiffness (Cg)
shear stiffness (Cd)
axial stroke (l)
angular stroke (g)
deformation cycle of the bellows expansion joint (seal)
vibration resistance	According to GOST 24346
impact resistance	The ability of the design of SC, UE to withstand the destructive effect of shock loads
tightness	The property of the design of the SC, UP to prevent gas or liquid exchange between media separated by the walls of the structure
loss of tightness	According to GOST 25756
buckling
probability of failure	According to RD 50-650 (GOST 27.002)
operating time
assigned operating time
Conditional pressure Ru	According to GOST 356
Test pressure Rpr

APPENDIX 2

Mandatory

TEST PROCEDURE

1. Acceptance tests

1.1. Acceptance tests (departmental, interdepartmental, state) are organized by the enterprise - product developer.

1.2. In the composition of the acceptance committee, in the general case, representatives are included: enterprise (organization)-customer (main consumer) - chairman; enterprise-developer - deputy chairman; manufacturer; enterprise - the developer of the object of application; representative of the state supervisory authority, if necessary.

1.3. Enterprises (organizations) notify the enterprise-developer in writing at his request about sending their representatives to the acceptance committee.

1.4. The selection committee works under the direction of the chairman, and in his absence - under the leadership of the vice-chairman.

1.5. Tests are carried out within the time limits determined by the schedule agreed with the test department.

1.6. Test units, as well as organizations, must be certified for the right to conduct tests in the manner established by the USSR State Standard.

1.7. The enterprise-developer provides the necessary working conditions for the acceptance committee.

1.8. The Commission is responsible for:

1) objectivity of conclusions and conclusions;

3) the timing and quality of execution of the materials of the commission based on the test results.

1.9. The Commission has the right:

1) require the provision of additional information about the samples submitted for testing;

2) invite specialists from other specialized organizations (enterprises) for consultations;

3) take a direct part in the tests;

4) in technically justified cases, count as test results the results of earlier quality checks of products;

6) appoint qualification tests in cases of insufficient confirmation of parameters and characteristics during acceptance tests;

7) accept as indisputable documents of the head organization for state testing or its basic testing divisions;

8) suspend tests in cases of violation of safety regulations or non-compliance of test or measuring instruments with the test program (methodology), until these violations are eliminated;

9) stop testing in cases of non-compliance of the parameters and characteristics obtained during testing with the requirements of the documentation and resume them after considering issues with interested organizations (enterprises) and making an agreed decision on further performance of work.

1.10. All decisions of the acceptance committee are documented in protocols indicating the officials present at the meetings of the committee. Test reports are drawn up in accordance with clause 4.2.

1.11. When participating in the work of the commission of the USSR Register, its representative signs the minutes of the plenary meetings of the commission. Upon completion of the work of the commission, the representative of the USSR Register draws up the “USSR Register Act”, which is an integral part of the materials of the acceptance commission. At the same time, his signature is not provided for in the act of the acceptance committee.

1.12. Each member of the commission, including the chairman and his deputy, has the right to state in writing his dissenting opinion on a particular issue considered by the commission. A dissenting opinion should be considered when approving the materials of the acceptance committee.

1.13. Registration of test reports must be carried out in accordance with Appendix 3, clause 2.2.

2. Qualification and periodic tests

2.1. Qualification and periodic testing is organized by the manufacturer of products with the participation of a representative of the customer (main consumer) and the state supervision body, if necessary.

2.2. In the case of testing at an enterprise (organization) that is not a manufacturer, the tests are carried out by the testing department of this enterprise (organization), certified in the manner established by the State Standard of the USSR, with the participation of a representative of the customer at this enterprise (organization) and the state supervision body, if necessary.

2.2.1. Tests are carried out within the timeframe determined by the schedule agreed with the test department. The schedule is drawn up by the person appointed responsible for the tests.

2.2.2. According to the test results, the testing department issues the test results to the manufacturer in the form of protocols.

2.3. Test reports are drawn up in accordance with clause 4.2.

Registration of test reports - in accordance with Appendix 3, paragraphs. 2.3, 2.4.

3. Acceptance tests

3.1. Acceptance tests are carried out by the technical control service of the manufacturer, and in cases specified when ordering, by a representative of the customer (main consumer) or a representative of the state supervision body. In this case, the acceptance of products by the technical control service precedes the acceptance of products by the customer (the main consumer) or a representative of the state supervision body.

3.2. The basis for the acceptance of products is a notification of its readiness, submitted by the manufacturer of the product.

3.3. Based on the results of acceptance, documents are drawn up, provided for by the regulations on the acceptance of products for industrial purposes, and a passport is filled out.

3.4. On compliance with the special conditions of the customer, specified when ordering products, a mark is made in the documents for its acceptance.

PROCEDURE FOR FORMING, SUBMISSION AND APPROVAL OF DOCUMENTS COMPILED ON THE TEST RESULTS

1. Documents drawn up based on test results

In general, the documents drawn up based on the results of testing prototypes and mass-produced products include:

1) test reports with applications;

2) test report (conclusion - during arbitration tests).

2. Requirements for the execution and procedure for approval of test documents

2.1. The procedure for issuing test reports - according to clause 4.2.

2.2. The procedure for drawing up, submitting and approving acceptance test certificates

2.2.1. Based on the results of consideration of the documents submitted to the commission (Table 1), the latter draws up an act. Registration of acts of the interdepartmental (departmental) acceptance committee - in accordance with Appendix 4, execution of acts of the state acceptance committee - in accordance with Appendix 5.

2.2.2. The act of the interdepartmental (departmental) commission is signed by the members of the commission, and the chairman of the commission approves the act.

2.2.3. The act of the state acceptance commission is signed by the chairman and members of the commission. The act is approved by the organization that approved the composition of the commission.

2.2.4. If the state tests are carried out by the basic testing division of the parent organization or the parent organization for state testing, then the test reports and annexes to them by the state commission are submitted by these testing divisions or the parent organization.

2.2.5. Documents drawn up based on the results of the work of the state acceptance commission, the chairman of the commission sends for approval to the organization that appointed the commission, with a letter signed by him and the head of the enterprise (organization) who conducted the tests. The term for consideration and approval of documents is no more than 15 days.

Note. Documents are sent unbound in one (first) copy.

2.2.6. After the approval of the documents under paragraphs. 2.2.2, 2.2.5 of this Appendix, the documents are returned to the enterprise - the developer of the SC (UE) for registration, making copies and mailing them to interested enterprises (organizations).

2.2.7. Acts of acceptance commissions according to paragraphs. 2.2.2 and 2.2.3 of this appendix are subject to registration (assignment of the next serial number in the year of drawing up the act) at the developer enterprise.

Registration of test reports is carried out after their approval.

2.2.8. Making copies of documents is allowed in any way that ensures unambiguous reading of documents. Sets of copies of documents must be bound and have a cover made of soft cardboard with a label indicating: the name of the topic, the designation of the NTD for products, the number and date of approval of the acceptance test report.

2.2.9. The enterprise-developer leaves the original copy of the documents (the first typewritten one) for storage, and sends the remaining copies (copies) within 10 days from the date of receipt of the approved copy of the documents:

to the customer (main consumer) - 1 copy;

to the head developer of a specific type of equipment, of which the SC or UE is an integral part (in the case of testing components) - 1 copy .;

manufacturer - 1 copy.

Note. The need to send materials to other organizations (enterprises) should be specified in the acceptance test report.

2.2.10. After registration of acceptance test documents, the enterprise - developer of the SC (UE) must perform the following activities:

approval and registration of NTD for products in the manner prescribed by GOST 1.3;

adjustment of design and technological documentation based on the results of acceptance tests in the manner prescribed by GOST 2.503.

2.3. The procedure for registration, submission and approval of certificates of qualification tests

2.3.1. Based on the results of qualification tests, the manufacturer draws up an act in which it indicates:

1) name, type and designation of products in accordance with the main design documentation;

2) designation of NTD for products;

3) serial numbers of samples;

4) the date of drawing up the document;

5) the purpose of the tests;

6) the name of the enterprise that conducted the tests;

7) the name of the enterprise - the developer of the SC (UP);

8) the period of time during which the tests were carried out;

9) compliance of the samples of the IC or UE presented for testing with the requirements of the design documentation and NTD for products;

10) the name and designation of the program and test procedure, in accordance with which the samples were tested;

11) the results of the tests carried out with a conclusion on the compliance of product samples with the requirements of design documentation and NTD for products;

12) elimination of product deficiencies (CD) identified by the acceptance committee and specified in the act;

13) the state of readiness of the manufacturer for the serial production of this product in a given volume;

Test reports with relevant annexes are attached to the act.

2.3.2. The act of qualification tests is signed by: a representative of the manufacturer (the person responsible for conducting tests), a representative of the customer (main consumer) at the manufacturer and a representative of the state supervision body, if necessary.

2.3.3. The act of qualification tests is approved by the head (deputy head) of the enterprise - manufacturer of SK, UP.

Registration of acts of qualification tests is carried out by the manufacturer.

2.4. The procedure for registration (except for listings 12-14, 16 of clause 2.3.1), submission and approval of acts of periodic testing of products is similar to that set out in clause 2.3 of this appendix.

2.5. The procedure for registration, submission of documents (conclusions) of other types of tests (examinations) of finished products (according to clause 1.5) - in accordance with the approved Charter (Regulations) on the enterprise (organization) that conducted the tests (examination), agreed in the prescribed manner with the bodies of the State Standard , and the procedure in force at this enterprise (organization).

2.6. Documentation rules

2.6.1. The text part of the documents (test reports and the materials attached to them, the test report and other documents) is typewritten and drawn up in accordance with the general requirements for text documents in accordance with GOST 2.105, on sheets of A4 white paper in accordance with GOST 2.301 without a frame, main inscription and additional columns to it.

2.6.2. The quality of execution of documents according to paragraphs. 2.6.1 and 2.6.2 of this Appendix should provide the possibility of making multiple copies or making a duplicate of them.

2.6.3. The name of the test object in all documents of one set and in the headings of the documents must be the same as the name of the product in the technical documentation for products and the main design document. Designation of products - according to GOST 2.201.

STANDARD FORM OF ACT

APPROVE Chairman of the acceptance committee position and name of the organization (enterprise) ___________________________________________ _______________________________________ ACT No. _______ acceptance committee ___________________________________________________________ interdepartmental, departmental on this topic ____________________________________________________________________ topic name name and type of product designation of the draft NTD for products; ___________________________________________________________________________ ___________________________________________________________________________ date of the document ___________________________________________________________________________ interdepartmental, departmental acceptance committee consisting of: surname, initials, position, organization (enterprise) surname, initials, position, organization (enterprise) __________________________________________________________________________ surname, initials, position, organization (enterprise) appointed by order (instruction) on ____________________________________ Name From __________________ No. ________________ organization (enterprise) date conducted acceptance tests of prototypes ______________________________ Name _________________________________________________________________________ products and their designation in accordance with the main design document; Developed factory sample numbers Name Name manufacturer. The tests were carried out in the period from ___________________ to ___________________ date date at the stand (stands) of the enterprise (organization) _________________________________ Name according to the program and methodology ___________________________________________________. document designation 1. Summary test results for all items of acceptance tests ________________________________________________________________ are given: 1) evaluation of the results obtained for each type of test in the form __________________________________________________________________________ conclusions about the compliance of the controlled parameter (characteristics) __________________________________________________________________________ requirements of the draft NTD and (or) the need to adjust the requirements established in them __________________________________________________________________________ numerical values ​​of parameters (characteristics); __________________________________________________________________________ 2) information about the noted defects and data on their elimination (if any); __________________________________________________________________________ 3) conformity assessment of test equipment, as well as measuring instruments __________________________________________________________________________ and testing the requirements of the program and methodology). 2. Conclusion on design documentation _____________________________ provides information __________________________________________________________________________ on the degree of compliance of the samples with the requirements of the design documentation and proposals for its adjustment to __________________________________________________________________________ production of an initial batch in preparation for mass production 3. Conclusion on the sufficiency of the tests carried out and the compliance of the samples with the requirements of the draft NTD ___________________________________________________ __________________________________________________________________________ __________________________________________________________________________ 4. A brief assessment of the technical and economic efficiency of products at a limit price and useful effect _________________________________________________ __________________________________________________________________________ 5. Brief assessment of the technical level and quality of products according to the map of the technical level and quality __________________________________________________________ __________________________________________________________________________ 1) on the possibility (feasibility) of putting products into mass production (without qualification tests or after them) _______________________________________________________________ __________________________________________________________________________ 2) on assignment of design documentation letter "01" ("A") after its adjustment (if necessary) based on the results of acceptance tests __________________________________________________________________________ __________________________________________________________________________ 3) on the possibility of further use of samples that have passed the tests (or an indication of their write-off) _______________________________________________ __________________________________________________________________________ 7. Instruction on the approval of the draft specifications __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ names of enterprises and organizations to which the act should be sent - __________________________________________________________________________ according to appendix 3) __________________________________________________________________________ Deputy Chairman of the Commission __________________ ____________________ Personal signature Signature transcript Commission members: __________________ ____________________

STANDARD FORM OF ACT

APPROVE Organization name date and number Order (Decision) ACT No. ________ acceptance state commission on the topic _________________________________________ topic name ___________________________________________________________________________ name and type of products; designation of the NTD project; ___________________________________________________________________________ serial numbers of samples subjected to tests ___________________________________________________________________________ date of the document State Acceptance Commission composed of: Chairman _______________________________________________________________ surname, initials, position, organization (enterprise) Deputy Chairman __________________________________________________________ surname, initials, position, organization (enterprise) and members: __________________________________________________________________ surname, initials, position, organization (enterprise) ___________________________________________________________________________ surname, initials, position, organization (enterprise) appointed by the Order (Decree) ____________________________________________ name of company dated _______________________ No. _________________, in the period from ____________________ date date by __________ reviewed the results of state testing of prototypes ___________________________________________________________________________ name of the product and its designation in accordance ___________________________________________________________________________ with the main design document; Developed factory sample numbers by the enterprise ____________________________________, manufactured by the enterprise Name And accepted by the technical control service Name manufacturer. The tests were carried out in the period from ____________________ to ___________________ date date at the booth(s) of the enterprise (organization) __________________________________ Name according to the program and methodology ____________________________________________________. document designation

Other requirements for the content of the document - in accordance with Appendix 4.

1) on the possibility (feasibility) of putting products into mass production and (or) exporting them ____________________________________ ___________________________________________________________________________

Applications: 1) acceptance test reports with applications. 2) Act of the Register of the USSR (if necessary). Send the act after approval: ___________________________________________________________________________ names of enterprises and organizations that should be ___________________________________________________________________________ act sent - in accordance with Appendix 3) ___________________________________________________________________________ Chairman of the Commission __________________ _____________________ Personal signature Signature transcript Deputy Chairman of the Commission __________________ _____________________ Personal signature Signature transcript Commission members: __________________ _____________________ Personal signatures Transcription of signatures

LIST OF MEASUREMENTS USED IN CHECKING THE PARAMETERS AND CHARACTERISTICS OF BELLOWS EXPANSIONS AND SEALS

1. Dial gauges IC of the first accuracy class - for measuring linear displacements.

2. Optical quadrants of types KO-1M and KO-3M - for measuring angular displacements.

3. Dynamometers of the DOR and DOS types of the second accuracy class - for measuring forces.

4. Pressure gauges of types MOSH and MTI not lower than the first class of accuracy - for measuring hydraulic pressure.

5. Sensors-accelerometers of the KD type - for measuring vibration displacements (vibration accelerations).

6. Sensors-accelerometers - for measuring the amplitudes of shock accelerations.

7. Electronic frequency meters types Ch3-33, Ch3-36, etc. - for measuring the frequency of vibrations.

8. Electronic or mechanical clocks of various types - to measure the current time of the test process (in hours, minutes, seconds).

9. Electronic or mechanical counters - for registering the number of loading cycles of samples of SC and UE by static movement (the number of cycles of operation of the stand).

Determination of the angular stiffness of SC and UE of universal type

1 - dynamometer; 2 - power body; 3 - beam; 4 - optical quadrant; 5 - bellows compensator; 6 - hinge; 7 - clamp; 8 - stand; 9 - earring

Determination of shear stiffness of SC and UE of universal and shear types

1 - bellows compensator; 2 - coupler (technological or regular); 3 - indicator; 4 - equipment; 5 - earring; 6 - dynamometer; 7 - rod of the power body; 8 - fixing bolt; 9 - clamp

Tests of SC and UE for vibration strength

axially

1 - vibration transducer table; 2 - rigid equipment; 3 - bellows compensator; 4 - sensors-accelerometers; 5 - device for static unloading of the mobile system of the vibration exciter; A - amplitude of movement of the table of the vibration exciter of the stand; А1, А2 - vibration displacement amplitudes of the bellows corrugation elements

Tests of SC and UE for impact resistance

position of the product during testing in the direction of the X-axis

position of the product during testing in the direction of the axes Y (Z)

1 - axis of action of the shock pulse of the stand; 2 - technological flanges; 3 - restrictive fittings SK, UP (if any); 4 - bellows compensator; 5 - cargo table of the stand; 6 - simulator of boundary conditions; 7 - snap

Tests of SC and UE of a universal type to confirm the probability of failure-free operation in compression-tension

1 - bellows compensator; 2 - bottom cap; 3 - top cap; 4 - intermediate flange; 5, 6 - coupler; 7 - crossbar; 8 - earring; 9 - adapter; 10 - hydraulic cylinder rod; 11, 12 - flexible hose; 13 - pressure gauge; 14 - pump; 15, 16 - shut-off valve; 17 - safety valve; 18 - clamp; 19 - stand; 20 - limit switch; 21 - pressure bar; 22 - indicator; 23 - technological stand (installation)

Tests of universal unloaded SC to confirm the probability of failure-free operation in compression-tension

1 - bellows compensator unloaded type; 2 - bottom cap; 3 - top cap; 4 - earring; 5 - adapter; 6 - hydraulic cylinder rod; 7, 8 - flexible hose; 9 - pressure gauge; 10 - pump; 11, 12 - shut-off valve; 13 - safety valve; 14 - stand; 15 - limit switch; 16 - pressure bar; 17 - indicator; 18 - clamp

Tests of SC and UE of a universal type to confirm the probability of failure-free operation during bending (turning)

1 - bellows compensator; 2 - bottom cap; 3 - top cap; 4 - hydraulic cylinder rod; 5 - hinge; 6 - fork; 7 - adapter; 8 - drive; 9, 10 - flexible hose; 11 - pressure gauge; 12 - pump; 13, 14 - shut-off valve; 15 - safety valve; 16 - clamp; 17 - stand; 18 - limit switch; 19 - pressure bar; 20 - optical quadrant

Test of SC of a shear-turn type to confirm the probability of failure-free operation when bending (turning)

1 - bellows compensator; 2 - bottom cap; 3 - top cap; 4, 6 - earring; 5 - adapter; 7 - beam; 8 - hydraulic cylinder rod; 9, 10 - flexible hose; 11 - pressure gauge; 12 - pump; 13, 14 - shut-off valve; 15 - safety valve; 16 - clamp; 17 - stand; 18 - limit switch; 19 - pressure bar; 20 - optical quadrant

Test to confirm the probability of failure-free operation of swivel-type bellows expansion joints

1 - bellows compensator; 2 - bottom cap; 3 - top cap; 4 - fork; 5 - adapter; 6 - earring; 7 - hydraulic cylinder rod; 8, 9 - flexible hose; 10 - pressure gauge; 11 - pump; 12, 13 - shut-off valve; 14 - safety valve; 15 - clamp; 16 - stand; 17 - limit switch; 18 - pressure bar; 19 - optical quadrant

Testing of SC and UE of a universal type to confirm the probability of no-failure operation during shear

1 - bellows compensator; 2 - bottom cap; 3 - top cap; 4, 6 - earring; 5 - lanyard; 7 - adapter; 8 - drive; 9, 10 - flexible hose; 11 - pressure gauge; 12 - pump; 13, 14 - shut-off valve; 15 - safety valve; 16 - stand; 17 - limit switch; 18 - pressure bar; 19 - indicator; 20 - clamp

Testing of universal unloaded SC to confirm the probability of no-failure operation under shear

1 - bellows compensator; 2 - bottom cap; 3 - top cap; 4, 6 - earring; 5 - lanyard; 7 - adapter; 8 - hydraulic cylinder rod; 9, 10 - flexible hose; 11 - pressure gauge; 12 - pump; 13, 14 - shut-off valve; 15 - safety valve; 16 - clamp; 17 - stand; 18 - limit switch; 19 - pressure bar; 20 - indicator

Test of SC of shear-rotary type to confirm the probability of no-failure operation during shear

1 - bellows compensator; 2 - bottom cap; 3 - top cap; 4, 6 - earring; 5 - lanyard; 7 - adapter; 8 - hydraulic cylinder rod; 9, 10 - flexible hose; 11 - pressure gauge; 12 - pump; 13, 14 - shut-off valve; 15 - safety valve; 16 - clamp; 17 - limit switch; 18 - pressure bar; 19 - indicator

Test to confirm the probability of no-failure operation of the SC (UE) of the shear type

1 - bellows compensator; 2 - bottom cap; 3 - top cap; 4, 6 - earring; 5 - adapter; 7 - hydraulic cylinder rod; 8, 9 - flexible hose; 10 - pressure gauge; 11 - pump; 12, 13 - shut-off valve; 14 - safety valve; 15 - clamp; 16 - stand; 17 - limit switch; 18 - pressure bar; 19 - indicator

PROCEDURE FOR ACCOUNTING, STORING, HANDLING AND DISTRIBUTION OF TEST DOCUMENTS

1. Accounting, storage and circulation of documents

1.1. The originals (the first typewritten copies) of the kits, including the test certificate (test reports), test reports and annexes thereto, are subject to accounting and storage in the technical documentation department (OTD) or the technical documentation bureau (BTD) of the enterprise that registered the act (Appendix 3 ).

1.2. The original of the set of documents is stored in folders in an unbound form for the possibility of re-copying or making a duplicate, if the stamp of the document does not require special order accounting and storage.

General rules for acceptance of original documents for storage, accounting, storage and circulation - in accordance with GOST 2.501.

1.3. Accounting, storage and circulation of copies of documents is carried out in accordance with the rules established by GOST 2.501. Storage of documents at the enterprises-developers is carried out in the case of NTD for these products.

1.4. The period of storage of test documents is 5 years, but not less than the period of periodic tests.

2.3. The transfer of the original documents of acceptance tests is carried out by decision of the Ministry (department) according to the subordination of the enterprise that conducted the tests.

INFORMATION DATA

1. APPROVED AND INTRODUCED BY Decree of the USSR State Committee for Product Quality Management and Standards dated October 25, 1990 No. 2686

2. INTRODUCED FOR THE FIRST TIME

3 REFERENCED REGULATORY DOCUMENTS

	Item number, applications
	APPENDIX 3; 2.2.10
GOST 2.105-79	APPENDIX 3; 2.6.1
GOST 2.116-84	1.11; listing 7
GOST 2.201-80	4.2.7, appendix 3, 2.6.5
GOST 2.301-68	APPENDIX 3, 2.6.1
GOST 2.304-81	APPENDIX 3, 2.6.2
GOST 2.501-88	APPENDIX 8, 1.2, 1.3
GOST 2.503-90	APPENDIX 3, 2.2.10
GOST 12.4.026-76
GOST 27.002-89
	APPENDIX 1
GOST 16504-81
GOST 18321-73	APPENDIX 1
GOST 24346-80
GOST 24555-81	APPENDIX 1
GOST 25756-83