Automatic blocking guarantees operation with the door closed, prevents a person from falling out of the cab during operation, and also excludes landing and exit “on the go” (with the door unlocked).
Cabins of electric cranes are placed under the bridge gallery and communicate with it by stairs. At the same time, the location of the ladder in the cab should not interfere with the work of the crane operator. On those cranes where the cabin is small and constrained by equipment and control equipment, it is recommended to take out the exit ladder to the gallery, if conditions permit, outside the cabin. This practice is justified in some enterprises.
Under unusual conditions, the cranes employed in the pile-driving workshops for cutting scrap metal with the help of electromagnets and battle balls work. The cabins of such cranes must have a reliable lining at the bottom, protecting the cabin and the crane operator from metal fragments. In this case, the open part of the cabin must be filled with a resistant, transparent material.
All cranes operating in the open air must have insulated, sewn on all sides and glazed cabins. In summer, sun visors are arranged in them, and in winter, electric heaters are allowed to be installed to heat them. However, they must be electrically and fireproof, connected to the electrical network after the main switch in the crane cabin. It is also recommended to insulate the cabins of such cranes, install mechanical wipers and window heaters. This eliminates the need to open windows in winter.
To create convenience for the crane operator, the Rules provide for equipping the cabins of new cranes with fixed seats, adjustable in height and in the horizontal plane. It is forbidden to use random objects (beams) for sitting on cranes. Electric lighting is provided, which does not depend on whether there is voltage on the electrical equipment of the crane. Crane lighting is installed on the crane itself.
Platforms, galleries, stairs and fencing equipment
In accordance with the Rules, for the convenient and safe maintenance of cranes, their mechanisms and electrical equipment located outside the cabin, provision is made for the arrangement of appropriate galleries, platforms and stairs.
Landing sites. Landing platforms with permanent ladders are arranged for the crane operator to enter the crane control cabin. Landing pads are of two types: end and intermediate. End are arranged at a dead end at the end of the span, near the wall of the building. Intermediate - when working in one span of several overhead cranes on a technologically advantageous, convenient and safe section of their work path.
The safest landing sites are located at the end wall of the building. Therefore, if no more than two cranes operate in the span on one crane runway, they should be placed at both ends of the building. Intermediate landing sites located along the span of the workshop require special attention during operation. Due to the small distance between the cab and the platform, there is a risk of injury to people.
At one of the factories, a team of foundry workers used an intermediate landing site to whitewash the building. At the end of the work, the plasterer lowered the spray gun and hoses onto the floor of the workshop. At that moment, an overhead crane passed by and injured a worker with a cab.
An important requirement of safety regulations for the arrangement of landing sites is to be sure to place them on the opposite side of the trolley wires. An exception, as with the placement of crane cabins, is allowed only when the trolley wires are not accessible for accidental contact with them from the landing site, stairs, cabin. The landing area must be sufficiently free and comply with the Rules. Rice. 10. Fencing of intermediate landing sites.
The distance from the floor to the lower parts of the ceiling or protruding parts of the structures is at least 1800 mm. The platform floor must be level with the car floor for a normal and safe transition from the platform to the car and vice versa. The gap formed between the cabin and the platform must be at least 60 mm and not more than 150 mm. Sometimes it is allowed to arrange a landing area below the level of the cabin floor (no more than 250 mm), if the overall height (1800 mm) cannot be ensured when the landing area is located on the same level with the cabin floor. It is also allowed to drive the cab onto the site (no more than 400 mm) with fully compressed buffers, if the landing site at the end of the building is made below the level of the crawl of the cab. The rules stipulate that the following clearances must be observed: between the landing area and the lower part of the cabin (vertically) - at least 100 mm: between the cabin and the landing area fence - at least 400 mm; from the side of the entrance to the cabin - at least 700 mm.
In some cases, when for structural or other production reasons it is not possible to directly enter the crane cabin, with the knowledge of the local Gosgortekhnadzor authorities, it is allowed to enter it through the crane gallery. When opening the door in the gallery fence, the trolleys running along the crane bridge are automatically de-energized.
When the main crane trolls are located above the level of the crane runways, landing on the crane is allowed only from the side where the main trolley wires do not pass; in all cases, at the crane stand, they must be protected by a shield of insulating material. Entrance to the cabin through the crane bridge, which has. lifting and transport operations are carried out with the help of an electric magnet and the location of the trolleys to power the magnet does not exclude accidental touching them, it is prohibited.
galleries. The flooring of galleries, all repair and other sites must be metal, made of steel corrugated or perforated sheets with holes no larger than 20 mm. At the same time, the Rules allow the installation of wooden flooring, if it is strong enough and meets fire safety requirements. Metal or wooden flooring must be laid along the entire length and width of galleries, platforms, and passages. All galleries and platforms intended for servicing cranes, as well as the end beams of overhead cranes, must be protected by railings 1 m high with a continuous lining at the bottom with a protective strip with a height of at least 100 mm. Galleries for passage along the crane runways must meet the above requirements and have comfortable, safe stairs. The passage gallery has a railing on the side of the span and on the opposite side, if it is not limited by a wall. Passage width - not less than 400 mm, and height - not less than 1800 mm. For the electrical safety of people, the galleries are located on the side of the span opposite the trolleys. The most successful should be considered the device of a light transitional gallery located above the level of crane runways with special passages in the metal columns of the building. It is not allowed to leave an unenclosed section of the gallery near the columns. When arranging a passage inside the column 1 m before approaching it, the width of the passage through the gallery is reduced to the width of the passage in the column.
Each gallery must have exits at least every 200 m. If there are impassable crane tracks (unenclosed passage less than 400 mm), people are prohibited from staying on them.
Stairs. Maintenance of cranes necessitates the installation of stairs to access platforms, galleries. Stairs should be comfortable and safe. The rules provide for a ladder width of at least "600 mm, and the distance between steps - no more than 300 mm. The width of the stairs on the crane itself is at least 500 mm. An exception is allowed for ladders less than 1.5 m high. These ladders, including intended for exit from the cabin to the crane gallery, can be made at least 350 mm wide.Steps of vertical stairs must be at least 150 mm away from the metal structures of the crane.
Ladders for access to landing, repair sites and galleries (for passage along crane tracks) must be located so that people on them are not accidentally clamped by a crane or its cabin. The angle of inclination of stairs to the horizon should not exceed 60 degrees. If the height of the stairs is more than 10 m, then every 6 - 8 m platforms are arranged.
Special requirements apply to inclined stairs. When they are inclined to the horizon by 75 degrees or less, they must have railings and flat steps made of steel corrugated or smooth sheets with a directional relief. It is allowed to perform steps of two or three rods.
Stairs with an angle of inclination to the horizon of more than 75 degrees. or vertical with a height of more than 5, starting from a height of 3.5 mm, must have protective arc-shaped fences. The arcs are located from each other at a distance of not more than 800 mm and are interconnected by at least three longitudinal strips.
Useful information:
General information about the installation of overhead cranes
During the installation of overhead cranes, the assembly units are enlarged, they are fed to the assembly site and laid out in the area of action of the lifting devices, the slings are lifted, the enlarged elements are lifted onto the crane runways, the mounted cranes are assembled and aligned.
The choice of the method of installation of bridge blocks depends on their design and weight, installation location: inside or outside the building, delivery time by manufacturers, construction readiness of the facility, building frame design, as well as the type and characteristics of lifting machines available to the installation organization.
The following methods of installation of overhead cranes are most widely used: - using tower or jib rail cranes designed for installation of building structures of buildings; - using self-propelled jib cranes; using building frame structures, including chain hoists fixed to columns or mounting beams, based on two adjacent trusses, less often directly on trusses.
Recently, the method of installation of cranes, fully assembled in the lower position, developed by the Institute "Gipromallurgmontazh", using the equipment of conveyor lines for the assembly and installation of blocks of building coverings, has become widespread.
The previously widely used method of mounting cranes using masts is currently used only in cases where other lifting devices or mechanisms are not available or cannot be used, for example, workshop conditions do not allow the use of a self-propelled crane, and its frame structures - to install a mounting beam.
The main disadvantages of this method are the large, compared with others, labor intensity (1.5-1.8 times), metal consumption, duration of work, as well as the need to install braces for attaching the mast inside the workshop.
Recently, the method of mounting overhead cranes with the help of hydraulic hoists designed by the Giprotekhmontazh Institute has begun to be introduced.
Enlargement of assembly units of overhead cranes.
The order of enlargement assembly and the degree of enlargement of assembly units of cranes are determined by the project for the production of works (PPR) depending on the chosen installation method and delivery conditions for cranes.
The purpose of pre-assembly of structures, mechanisms and electrical equipment of overhead cranes is to perform the maximum amount of assembly work in the lower position and, accordingly, reduce to a minimum the number of operations performed at height. Therefore, the best option is one in which the bridge, fully assembled in the lower position, together with the trolley installed on it, or separately the bridge and then the trolley, are raised onto the crane runways. However, it is often not possible to lift and install a fully assembled crane bridge on the crane tracks due to the insufficient carrying capacity of the existing mechanisms and devices, the limited space under the boom space of the self-propelled cranes used, the impossibility (due to lack of space) to deploy the assembled crane bridge in a horizontal plane above the crane tracks . In addition, it is not always economically feasible to manufacture stands and equip sites for assembling crane bridges.
Most often, crane bridges are mounted in two or four assembly units, a trolley is mounted with one enlarged block and a control cabin is mounted with another.
Enlargement assembly of bridges. The metal structures of bridges are enlarged in the lower position in cases where the bridge is lifted onto the crane runways in one block. To do this, on the pre-assembly site (if space permits) or on a site specially allocated for this purpose, as close as possible to the installation site, racks for assembling bridges are installed. The racks must have a horizontal surface, two parallel rails are laid on top of them, the distance between which is equal to the span of the crane, and the length is 2.5-3 m more than the crane base on each side.
On the racks, using self-propelled jib or operating overhead cranes (if the site is located in the workshop), the crane bridge is assembled. In this case, if the bridge is supplied by the manufacturer separately in the form of two main and two end beams (Fig. 74, a), four assembly joints of the main beams with the end beams are assembled. If the bridge is supplied in the form of two main beams together with parts of the end beams (half-bridges), the joints connecting the parts of the end beams are assembled: two - if the main beams come into installation with halves of the end beams (Fig. 74, b), and four, if to the main beams are attached to the extreme parts of the end beams, and their middle parts (inserts) 3 are supplied separately (Fig. 74, c).
Mounting joints are assembled in two stages: first, on mounting (assembly) bolts, and after alignment and elimination of distortions, finally, on welding, clean bolts or rivets in accordance with the instructions in the working drawings.
When assembling the bridge, delivered according to the scheme shown in Fig. 74, but, first, end beams with wheels or balancers are installed on the rails laid on the racks and fixed (temporarily fixed) in the desired position. After that, one of the main beams is inserted between the end beams until the holes for the mounting bolts in the joints are aligned and they are connected with bolts. Then they are also installed and connected to the end - the second main beam.
The assembly of crane bridges, delivered according to the schemes shown in fig. 74, b, c, begin with the installation of half-bridges with wheels or balancers on racks. If the bridges are supplied according to the scheme shown in Fig. 74, c, then the middle parts of the end beams - inserts - are installed between the half-bridges. Then the half-bridges are brought together and the holes for the mounting bolts in the butt plates are aligned according to the marking scheme, after which they are connected with bolts.
74. Schemes for the delivery of an iosga crane a - separately main and end beams: b - main beams with halves of end beams; in - the main beams with the extreme parts of the end beams and inserts; 1 - main beam; 2 - end beam; 3 - insert
Before assembly, the surfaces of the butt elements are thoroughly cleaned of dried soil, paint and rust, and the surfaces of the welded butt elements are cleaned to a metallic sheen. When assembling the joints, it is necessary to achieve the maximum coincidence of the holes and not allow them to be adjusted by stretching them with conical mandrels, as this creates additional stresses in the metal. The tightness of the butt linings is checked with a probe: a probe plate 0.1 mm thick should not pass between the lining and the body of the end beam.
Rivet joints are assembled by driving mandrels (plugs) into holes (for rivets), with which 10-15% of the holes are evenly filled on each side of the assembly joint. At the same time, mounting bolts are installed with which 20-25% of the holes are evenly filled. The nuts on the bolts are not fully tightened.
To assemble assembly joints, in addition to cranes, use lever winches, jacks, as well as the simplest devices for temporarily fixing bridge elements in the desired position: supports, linings, brackets, shoes, etc.
After the bridge is assembled, platforms are attached to the outer walls of the main beams, stairs and railings are installed.
The crane bridge assembled on the mounting bolts is verified, for which it is checked and compared with those indicated in the drawings or the passport: the squareness of the bridge, the span of the crane, the gauge of the cargo trolley, the building lift of the bridge, the installation of trolley rails and running wheels of the crane.
The squareness of the bridge is checked in one of two ways: by the difference of the diagonals or by the alignment method (using a theodolite). Diagonals are measured by symmetrical points of the bridge, which can be the intersection points of the longitudinal and transverse axes of the running wheels; in practice, they are carried out on end beams or trolley rails (Fig. 75), but the dimensions a and a ', b and b ' must be respectively equal to each other. Measurements of diagonals are often carried out at points transferred to the end beams from vertical tangents to the circumferences of the wheel flanges. If the squareness of the bridge was checked at the factory (which is recorded in the crane passport), then during installation, measurements of the diagonals are made according to the control risks marked on the end beams or trolley rails. The difference between the diagonals of a rectangular bridge should not exceed 5 mm.
75. Crane bridge alignment scheme using a tape measure
76. Crane bridge alignment scheme using theodolite
1 - theodolite; 2-5 - wheels; 6 - target mark
With large spans of the crane, this method of verification is not accurate enough, since measuring large lengths with a tape measure requires constant tension of the steel tape; moreover, it is practically not always possible to measure the diagonals on the crane bridge. In these cases, the second method is more often used, which consists in the following.
At point A, at the distances indicated in fig. 76, install the theodolite, and at point B - target Mark 6. Combine the target axis of the theodolite with the center of the target mark, then turn the telescope of the theodolite 90 ° in the horizontal plane (along the limb) and fix it. Then the distances X\, Xr, Xs and X4 are measured from a plumb line installed along the sighting axis of the theodolite to the end surface of the wheels along a chord passing through points at least 300 mm away from the axis. The chord length is assumed to be the same on all wheels. After that, the theodolite is transferred to point A ', and the target mark to point B ' and similar measurements are made on the wheels.
The condition for the squareness of the bridge is the equality of the dimensions xx and x4, Xg and x3, as well as xb, taken between wheels 3 and 4, 2 and 5. The permissible deviation of these dimensions from each other is 3 for flanged wheels, and 4 mm for flangeless wheels.
The second method also allows you to simultaneously check the misalignment of the running wheels in the horizontal and vertical planes, since the difference in the sizes xx and X2, Xb determines the misalignment in the horizontal plane, and the difference in distances from the vertical plane to similar points located at the ends of the vertical chord characterizes the misalignment in vertical plane.
In the first method of checking the squareness of the bridge, the wheel misalignments are determined in the same way, but instead of the sight line of the theodolite, a string and a plumb line are used. Deviations of the end surfaces of the wheels from the horizontal and vertical planes should not exceed i mm per 1000 mm of the wheel diameter. The same tolerance is set for the deviation of the ends of the wheels from the common plane.
If deviations from the squareness of the bridge exceed the specified values, then the misalignment must be eliminated.
The most common way to correct the geometric shape of crane bridges is as follows. At one of the corners of the bridge with a larger diagonal, a stop is placed to prevent its longitudinal and transverse movement, and at the other corner - a jack. After loosening the tightening of the mounting bolts, the jack force is directed along the axis of the main beam, which is moved until the diagonal difference becomes equal to zero or within tolerance. Another way to correct the shape of the bridge is that, after fixing one end beam, the second one is moved in the direction of the axis of the crane runway rail.
The permissible deviation of the crane span LK, measured in the middle of the bearing surfaces of the running wheels for cranes with LK up to 40 m, is ± 6 mm, for cranes with LK more than 40 m - ± 7.5 mm.
Deviation at the joints of bogie rails 2 in plan and in height should not exceed 1 mm, and the gap in the joints should not exceed 2 mm.
The allowable gap between the sole of the bogie rail and the gasket or the upper chord of the beam depends on the type of rail and can be at the edges of the sole (see dimension d in Fig. 77) from 0.75 mm for the P4 rail to 2.5 mm for the SKR140 rail. In the middle part of the sole, this gap should not exceed from 0.3 mm (P4) to 1 mm (skr140).
Distortions of the running wheels that exceed the above tolerances are eliminated with the help of gaskets installed between the plates and axle boxes of the wheels in the end beam or balancer, while ensuring that the position of the wheels corresponds to the dimensions obtained during assembly at the factory and recorded in a special form, attached to the passport of the crane.
The final connection of field joints for welding is carried out by welders certified according to the rules of Gosgortekhnadzor at a temperature of at least minus 10 ° C in compliance with the technical requirements of the manufacturer.
Clean bolts used for joints of field joints should have a length of the uncut part of 8-10 mm less than the thickness of the package of connected elements. Insert them into the holes tightly, using a hammer. The tightening of the bolts during the final assembly of the joints must ensure a snug fit of the parts to be joined. In a tightened joint, a probe 0.1 mm thick can enter between the parts to a depth of not more than 20 mm at any joint.
The riveting is made by manual pneumatic hammers. This is a very time-consuming and difficult operation, therefore, they strive to perform the maximum amount of riveting work in the lower position, before lifting the assembly units onto the crane tracks.
Before riveting, clean bolts are tightened to secure the lining at the joints.
Then, holes for rivets are checked with a caliber 1.5 mm less than the nominal diameter of the hole and burrs are removed at the edges of the holes, while the depth and width of the countersinking of the holes should not exceed 1.5 mm.
Enlargement of half-bridges of cranes consists in the installation of a running gear and a drive of the movement mechanism (if they are supplied separately), as well as platforms. Sometimes, during the pre-assembly of half-bridges of cranes, delivered according to the scheme shown in fig. 74, in, in the middle of the end beams are placed on one of the half-bridges in order to reduce the amount of assembly work at height. Such an enlargement scheme is used when it is possible to turn the enlarged half-bridge in a horizontal plane during lifting.
The undercarriage of the crane movement mechanism, in which the main beams rest directly on the balancers with running wheels, is installed by rolling them along the rails under the main beam, and after aligning the holes, they are connected with an axle (connecting roller).
The installation of the undercarriage of cranes, in which the main beams rest on the main balancers (Fig. 78), begin with the attachment of small balancers with running wheels to them. For this, small balancers are first installed and temporarily fixed on the rails, to which the main balancer is fed on the hook of the lifting mechanism. Axes are inserted into the aligned holes in the main and small balancers. Then the main balancer assembly with the small ones by the same lifting mechanism is fed to the end of the main beam, laid on the lining of the sleepers, and after the holes are aligned, they are connected to the axis.
The position of balancers with wheels is adjusted by spacer rings installed on the axle on both sides of the balancer in accordance with the factory marking. Incorrect installation of distance rings or their absence can change the span of the crane, which is unacceptable. The installed balancers are checked for the absence of jamming by swinging them on their axes.
The drive of the crane movement mechanism is assembled after installation and alignment of the running gear, and the alignment and connection of the output shaft of the gearbox with the axis of the drive wheel in the end beam or balancer - after the final connection of the assembly joints of the bridge metal structures. The most difficult operation when assembling the drive is the alignment of gear couplings of the MZ and MZP types (with an intermediate shaft). The condition for the correct connection of the shafts is their alignment and the absence of distortions (within tolerances).
78. Scheme of hanging balancers on the main beams
1 - hook of the lifting mechanism; 2 - main beam; 3 - holes; 4 - main balancer; b - small balancer
79. Scheme for determining misalignment and radial displacement of couplings
a - type MZ; b - MZP type
When assembling couplings of the MZ type (Fig. 79, a), they control the radial displacement a, which characterizes the misalignment of the connected shafts, and the misalignment, determined by the linear value s - tn-n or the angle co. The values a, m and n are determined at four points (in two mutually perpendicular planes). The highest allowable value of co = 0°30.
When assembling couplings of the MZP type (Fig. 79.6), the radial displacement a and the distortions e-b-c are controlled.
Permissible values of a, s, b, c and e depend on the dimensions (numbers) of the couplings, they are indicated in the technical documentation of the manufacturer.
In the process of alignment, the shafts to be connected are aligned, i.e., they achieve their alignment and eliminate distortions, after which the couplings are finally assembled.
Last of all, electric motors and brakes are installed, the position of the electric motors is adjusted, their shafts are aligned with the shafts of the gearboxes and fixed on the under-engine plate or frame.
The brake must be installed so that its center coincides with the center of the brake pulley. Non-parallelism and misalignment of pad surfaces relative to the working surface of the pulley should not exceed 0.1 mm for every 100 mm of the pulley width, and radial runout - 0.05 mm per 100 mm of the pulley diameter.
Pre-assembly of carts. Crane trolleys with a lifting capacity of up to 50 tons inclusive are supplied by the manufacturers fully assembled and ready for installation on the crane bridge.
Crane trolleys with a lifting capacity of 80 tons and more are supplied in separate assembly units according to the following schemes: – trolley frame assembled with a movement mechanism, main and auxiliary lifting mechanisms - assembly units; - half of the frame with the travel mechanism (without running gear) and the main lift mechanism, half of the frame with the auxiliary lift mechanism and with the running gear of the travel mechanism; - the frame of the cart as a whole, the mechanisms of movement, the main and auxiliary lifts - assembly units; - bogie frame in parts, movement mechanisms, main and auxiliary lifts - separate assembly units.
Obviously, the greatest amount of work on pre-assembly has to be performed when bogies are delivered according to the last of the above schemes (this is how crane bogies with a lifting capacity of 200/32 tons and more are delivered). The pre-assembly of the trolley is carried out on a special stand with rails or on a crane bridge. It is possible to assemble the trolley on a sleeper cage, and then on the crane bridge to carry out the final alignment of the undercarriage of its movement mechanism. First, the trolley frame is assembled (if it is supplied by the manufacturer in separate parts) on the mounting bolts and the running gear of the movement mechanism is installed: wheels or balancers.
When assembling the frame, its squareness is checked by measuring the diagonals at the points marked with risks at the factory during the control assembly of the cart or directly at the installation site. Diagonal difference should not exceed 3 mm.
After that, the correct installation of the running wheels or balancers is checked in the same way as the running gear of the crane movement mechanism. At the same time, in addition to the misalignment of the running wheels, the displacement of the vertical plane of symmetry of the running wheel from the same plane of the rail is checked, which is allowed no more than 2 mm, as well as the support of the trolley on the trolley rails by all wheels (the centers of the running wheels must be located in the same horizontal plane). ) and the base of the trolley, measured on one side and the other, the tolerance of which is ± 2 mm. After alignment and elimination of distortions of the frame and chassis of the gel, the final assembly of the frame is riveted or welded in accordance with the instructions in the manufacturer's drawings. Sometimes the undercarriage of the trolley movement mechanism is assembled on an inverted frame, which is then turned over to the design position.
After riveting or welding the trolley frame, the movement mechanism is finally assembled: the gearbox is installed (preliminarily), the gear couplings and shafts are assembled and aligned, and they are also connected to the wheels, after which the gearbox is fixed. Then a brake and an electric motor with a coupling half made in the form of a brake pulley are installed, the shafts of the electric motor and the gearbox, the brake are centered and fixed with bolts. If it becomes necessary to put the coupling half on the motor shaft, this is done with light blows of a wooden or copper hammer, while the opposite end of the shaft is given a stop; the coupling half is preheated to 60-80 °C.
Assembly units of lifting mechanisms are based on machined plates, so it is not necessary to adjust their position in height with pads.
The main lift mechanism is assembled in the following sequence: a drum with block bearings and a rack is installed (after they are aligned and fastened, locking wedges are clogged and seized by electric welding), small gears of an open transmission and a gearbox, and then an electric motor and a brake.
The assembly of the auxiliary lifting mechanism begins with the gearbox, and then the drum, electric motor and brake are installed.
When installing the drums of the main and auxiliary lifts, special attention should be paid to the correct assembly and alignment of the open gears.
The gear teeth of the output shaft of the gearbox must be evenly sunk between the teeth of the driven gear of the drum. When aligning, it is necessary to ensure the center distance specified in the drawings and the absence of misalignment of the axes.
The correctness of the assembly is determined by the values of the maximum deviations of the side clearance and center distance, as well as the size of the contact patch of the teeth, which is checked for paint.
Electric motors and brakes are installed after complete assembly and alignment of the mechanisms. At the same time, gear couplings and shafts are assembled and aligned. The misalignment and mutual displacement of the shafts of electric motors and gearboxes must be within the tolerances specified in the manufacturer's drawings, and in any case should not exceed the value allowed for the gear coupling of the corresponding number.
After assembling the crane bridge or enlarging the half-bridges, as well as after assembling the bogie, before lifting the assembly units onto the crane tracks, the electrical equipment is mounted. This work is performed by a team of electricians who, in accordance with electrical installation drawings, install terminal and adapter boxes, stands for electrical devices, lay wiring harnesses in boxes and metal sleeves.
Then, electrical devices (transformers, starters, resistance boxes, etc.) are installed, making sure that the width of the passages between them and the railing of the bridge platform fence is at least 400 mm. After that, the ends of the electrical wiring are connected to the terminals of the electrical equipment, the grounding of the electrical equipment and electrical wiring is mounted.
Control cabins of overhead cranes are delivered for installation, as a rule, with a high degree of electrical installation readiness. But sometimes cab electrical installation has to be carried out at the car park assembly site, including the installation of a protective panel, controllers, lamps, limit and emergency switches, buttons, terminal and junction boxes.
Also, before lifting the bridge (or half-bridges) of the crane, crane lighting fixtures are installed and connected.
If the assembly units are enlarged away from the place of installation of overhead cranes in the design position, then after the enlargement they are fed into the installation area along the railway tracks on platforms, special carts or vehicles on trailers. When the pre-assembly site is located near the installation site of overhead cranes, the assembly units are fed into the installation area by pipelayers.
In the installation area, assembly units are laid out in accordance with the chosen installation method and depending on the availability of free space on the site.
If there is enough space, the net assembly units are brought into the installation area completely and laid out in such a way that the heaviest of them are in the area of the lifting devices and it would not be necessary to drag them to lift them to the design position.
If, due to lack of space for layout, it is impossible to bring all the assembly units of the crane to the installation site, they are served according to an agreed schedule, specified before each enlarged unit is submitted. The most effective is "mounting from wheels", i.e. lifting the crane assembly units directly from vehicles.
Slinging. This operation is very responsible in the production of rigging work and must be carried out in strict accordance with G1PR, which indicates the slinging patterns of assembly units and the diameter of the rope used for the manufacture of slings. Changing the slinging scheme or replacing the rope is possible only with the permission of the organization that developed the PPR.
Crane assembly units must be raftered by experienced riggers.
When choosing a slinging knot and the number of rope threads in a sling, they tend to use slings with the smallest possible number of threads by increasing the diameter of the rope, but not more than 39 mm, since it is difficult to knit knots with a rope of large diameter, especially when slinging with a dead loop knot, and splicing the ends of the rope with a straight knot ("eight").
When lifting assembly units of a small mass, slinging is performed with a universal or lightweight sling.
When lifting heavy assembly units for a sling, a steel rope of such a length is used that is necessary for slinging according to the accepted scheme.
The ends of the ropes in these cases are connected with straight or bayonet knots, as well as with the help of various clamps.
Beams of box-section bridges are rafters with various knots (Fig. 80). A simple ring knot (Fig. 80, a) is performed with universal slings or from pieces of rope.
Most often, beams are slinged with one or two “dead loop” knots (for a noose) (Fig. 80, b, c). Since the beams are lifted together with the platforms and elements of the movement mechanisms, the center of gravity of the assembly unit being lifted is shifted from the axis of symmetry of the beam section by the value K. Therefore, when slinging, the “dead loop” assembly is displaced (see Fig. 80.6) by this value, which can be determined by calculation or, as is done in practice, by trial lifts to a height of 100 mm, followed by re-slinging, if necessary. Sometimes, for the same purpose, an auxiliary sling with a spacer is used (see Fig. 80, c), which perceives the overturning moment caused by a shift in the center of gravity.
80. Slinging beams of box-section bridges
a - a simple ring knot "in the girth"; b - displaced knot "dead loop"; in - knot "dead loop" with an auxiliary sling; g - a knot with an overlapping thread; 1 - bridge beam; 2 - bracket; 3 - sling; 4 - lining - 5 - platform: 6 - hook or bracket of the lifting mechanism; 7 - spacer; 8 - auxiliary sling; 9 - overlapping thread; 10 - squeeze
The beams of heavy-duty cranes are often slinged with a knot with an overlapping thread 9 (Fig. 80, d), which ensures reliable fixation of the threads of the main sling and in which this knot differs from a simple ring knot. In these cases, an auxiliary sling is also used. To ensure the stability of the beam being lifted, the distance L between the slings or the spacing of the branches of one sling must be no less than half the height of the beam R, i.e. L> >0.5 I.
In order to protect the rope from damage on the sharp edges of the lifted loads, inventory metal linings or wooden linings are placed under it.
In some cases, the crane manufacturer or installers (in agreement with it) weld lugs (with reinforcement elements) to the upper chords of the beams to attach the movable block of the chain hoist of the lifting mechanism (Fig. 81). In these cases, there is no need for rope slings, and the movable block of the chain hoist is attached to the beam 1 with the help of pin 5, fixed in the holes of the eye and earring of the block.
The slinging of the assembled crane bridge is carried out with ring nodes as shown in fig. 82. To prevent deformation of the bridge during the lifting process, pipe spacers are installed between the main beams, adjustable in length.
The crane trolleys are slinged over the frame beams so that the branches of the sling, enveloping the equipment parts, do not damage them (Fig. 83).
Carts of small carrying capacity are slinged with universal slings or tying with a rope under the frame (Fig. 83, a, b). If there are special sling devices on the trolley frame - bosses, trunnions, brackets, etc., then they sling for these devices. Heavy duty crane trolleys are slinged behind the main frame beam linking the side beams. On fig. 83, in it is shown that the slinging of the cart is made with two slings: the main one, tying the main beam of the frame, and the intermediate one, tied to the main sling and going to the hook or bracket of the movable chain hoist of the lifting mechanism. Other schemes for slinging heavy carts are also used - without intermediate slings.
81 Attaching the chain hoist to the eye
1 - bridge beam; 2 - reinforcement: 3 - eyelet; 4 - block clip earring; 5 - finger
82. Scheme of slinging of the crane bridge 1 - the end of the beam; 2 - sling; 3 - lining; 4 - main beam; 5 - spacer
83. Schemes for slinging trolleys of overhead cranes
a. b - universal or rope sling under the frame; c - main and intermediate lines; 1 - intermediate sling; 2 - main line
Lifting assembly units of cranes on crane tracks. This operation is the most critical operation during the installation of overhead cranes and must be carried out in strict accordance with the PPR (with installation diagrams and instructions for ensuring safe working conditions). The installation scheme may be changed in those cases when it becomes impossible (for various reasons) to use the lifting mechanisms originally provided for in the project, or when the situation at the installation site changes.
The most difficult operation for lifting crane assemblies is the lifting of main beams, half bridges and fully assembled bridges.
Two main ways of installing them on crane tracks are used: - lifting the half-bridge (the main beam or the entire bridge) above the crane tracks in a position when it is oriented along the span or at some angle to its longitudinal axis, then turning in a horizontal plane and lowering onto the crane tracks .
The possibility of installing a half-bridge in this way is determined by the distance from the axis of the crane rail to the wall of the building, as well as the width of the half-bridge; - lifting the half-bridge in an inclined position - "fish", when one of its sides is ahead of the other. After one side passes the crane beam, the half-bridge is withdrawn or pulled to the same side and the second side of the half-bridge is carried past the second crane beam, and then the half-bridge is lowered onto the crane runways.
The sequence of lifting assembly units of cranes depends on the degree of their enlargement and practically does not depend on the lifting mechanisms used for this purpose.
So, if the crane is mounted with two half-bridges (main beams with end parts), then one half-bridge is first lifted onto the crane tracks, then the other, the mounting joints are connected, after which the crane trolley is lifted and installed on the bridge, followed by the control cabin.
Another version of this scheme is often used, when the half-bridges raised and installed on the crane runways are bred to a distance exceeding the width of the trolley by 400-600 mm, then it is raised between the raised half-bridges above the trolley rails, after which the half-bridges are brought together, the mounting joints are connected and the trolley is lowered to bridge.
If the crane bridge is assembled from two main and two end beams, then first they lift it onto the crane tracks and temporarily fix one end beam on them, then the second, then, in turn, raise the main beams and join them with the end beams, then lift and install a trolley on the bridge, and then mount the cabin.
In cases where the half-bridge of the crane, in which the main beams rest on the balancers, cannot be lifted together with them (the load capacity of the existing mechanisms is insufficient), the balancers with the balancing carts are first lifted and temporarily fixed on the crane tracks. Then one main beam is raised and its ends are connected to the balance beams, the second beam is also lifted and installed on the balance beams, after which they are alternately lifted and joined to the main end beams. The sequence of mounting the bogie and the control cabin is the same as in the first of the above schemes, including lifting the bogie between the raised half-bridges, bringing them closer together, connecting the joints and lowering the bogie onto the bridge.
The smallest number of lifts in cases where overhead cranes are installed in the design position with two or one mounting block: in the first case, the bridge and the trolley, in the second case, when the fully assembled crane (together with the trolley attached to its bridge) is installed on the crane tracks.
Regardless of the sequence in which the overhead crane is assembled on the crane tracks, the final connection of the assembly joints on the crane bridge should be carried out only after its alignment, which is carried out in the same way as when assembling the bridge in the lower position.
In the process of assembly, the half-bridges move along the crane runways with the help of manual lever winches (mounting traction mechanisms). Guys in the process of lifting, turning and installing half-bridges on the crane tracks are controlled manually (with a hemp rope). The exception is the braces, with the help of which the half-bridge is retracted to the side when lifting in an inclined position - “fish”. These guys are made of steel rope and are controlled by hand-operated lever winches.
84. Scheme of lifting half-bridge with two cranes
1 - tower crane BK-1000; 2- half bridge of the mounted crane; 3 - crane SKR-1500
The most effective for lifting assembly units of overhead cranes are tower or jib rail (type SKR) cranes, which are used to mount the structure of the building frame. This method is possible when overhead cranes are delivered before or during the erection of the building frame. In these cases, the installation of assembly units or cranes completely assembled in the lower position is carried out simultaneously with the installation of the building structures of the building until it is overlapped, or an opening is left in the ceiling that is sufficient to supply it through half-bridges and trolleys to the installation site; subsequently the opening is closed.
Depending on the location of the tower cranes at the construction site, when the lifting capacity of one crane at the required hook reach is not enough, the overhead crane assembly units are lifted by two tower cranes (Fig. 84).
The advantages of this method are that, firstly, there is no need for other lifting machines, and secondly, the possibility of combining the installation of the building frame and overhead cranes, which allows them to be put into operation in advance and then used not only during installation equipment, before and before that - during the construction of foundations for it. The use of tower cranes, in addition, makes it possible to mount overhead cranes at high altitudes, for example, in the high-rise part of oxygen-converter shops, in the “shelves” of mine headframes, etc.
The main factor hindering the most widespread use of this method is the late delivery of overhead cranes, i.e. after the construction of the building frame, when the tower cranes have already been dismantled.
In addition, Fie can always mount any assembly unit of an overhead crane due to the insufficient lifting capacity of the tower crane at the required reach of its hook.
The use of erection self-propelled cranes for lifting assembly units of overhead cranes onto crane tracks is one of the most common methods for mounting these cranes.
The conditions for the use of mobile cranes inside the building for this purpose are: - openings in the building for the crane to pass into the installation area; – leveled and compacted platforms for installation of cranes on them; - sufficient bearing capacity of the ceilings of basements and channels in the area of the passage of the crane; - the presence of self-propelled cranes with load-altitude characteristics that provide lifting and installation in the design position of the elements of the mounted crane; these characteristics include the carrying capacity, which, on the given hook outreaches, must correspond to the mass of the load being lifted, as well as the space under the boom (size a in Fig. 85), which should ensure the lifting of the elements of the mounted crane without resting them against the boom and be at least 200 mm.
In addition, the mounting crane must fit with its boom into the dimensions of the building in which the bridge crane is mounted: the distance h (see Fig. 85) from the top of the boom in its highest position to the roof must be at least 200 mm.
85. Scheme of installation of half-bridges of an overhead crane on crane tracks with one assembly crane
86. Scheme of lifting the overhead crane trolley with two mobile cranes
1 - crane; 2 - traverse; 3 - sling; 4 - spacer between the main beams of the bridge; 5 - crane bridge; 6 - crane beam; 7 - arrow
87. Scheme of lifting the crane bridge by a mobile crane with special boom equipment
The often limited under-boom space and capacity at the required hook reach are the main obstacle to lifting a fully assembled bridge or bogie with a single erection crane. In such cases, large-sized elements are lifted by two cranes (Fig. 86). Sometimes specially made boom equipment is used for this purpose (Fig. 87), which is a tubular boom with a traverse, the reach of which makes it possible to place a fully assembled crane bridge in the under-boom space, and with the boom vertical, the mounting crane has a maximum load capacity.
On fig. 85 shows a diagram of the installation of two half-bridges 2 and 3 of an overhead crane on the crane tracks using a mounting crane. The dotted line marks the position of the mounting crane when lifting half-bridge I, as well as the initial positions of both half-bridges. The bridge of the net according to this scheme is assembled as follows. First, the half-bridge is raised from its original position, deployed in a horizontal plane above the crane runways and lowered onto them, and then, using mounting traction mechanisms, it is driven to the position shown in the figure. Then the assembly crane moves to the right, to the position marked with the position, and with its help the half-bridge is lifted and installed on the crane tracks in the same way as the half-bridge.
The bridge is assembled depending on the accepted trolley installation scheme: if it is fed to the bridge from the side, then the half-bridges are joined immediately after they are lifted onto the crane runways; if the bogie is lifted between the raised half-bridges, then they are joined after the bogie is raised above the bogie tracks and before the bogie is lowered onto them. The assembly crane in this case, to lift the trolley, is installed under the raised half-bridges in the middle so that its boom is directed along the half-bridges, and the cargo block is above the center of mass of the trolley. After installing the trolley on the crane bridge, it is released from the slings and the assembly crane is driven away, while lowering its boom between the half-bridges.
When the carrying capacity of one crane is not enough, half-bridges, followed by a turn and installation on crane tracks, are lifted by two assembly cranes. In this case, the half-bridge is slinged from both sides, raised above the crane runways and, alternating the maneuvering of the booms with the change of crane stands, the half-bridge is deployed in a horizontal plane, after which it is lowered onto the runways.
Two mounting cranes raise the half-bridges in an inclined position - a "fish" (Fig. 88). After one side of the half-bridge is raised above the crane runways, by turning the booms of the cranes, the half-bridge is taken to this side and the other side of the half-bridge is raised above the runways. Then, by turning the crane booms in the opposite direction and changing the height of their rise, a half-bridge is installed on the crane tracks.
88. The scheme of lifting the half-bridge with two assembly cranes
As shown in Fig. 85 and 88 schemes raise the main beams of bridges to the crane tracks with the difference that according to the second of these schemes, the ends of the main beam should be raised above the end beam or balance beam (and not the crane tracks), which are installed up to the main beams.
89. Scheme of installation on nodcrane tracks of the end beam
1 - end beam; 2 - corner; 3 - latch; 4 - I-beam; 5 - column; 6 - crane rail
When installing erection cranes from the side of the half-bridge platforms, if necessary, these platforms are not installed or the flooring and railings of the fences are cut out in the places where the crane booms pass.
On fig. 89 shows a diagram of the installation of an end beam or balance beam on the crane tracks, when the crane bridge is assembled from four beams (two of which are together with the undercarriage) or from four beams and balance beams lifted separately.
For temporary fixing of end beams or balance beams on the crane runways, various devices are used, one of which is shown in Fig. 89. It includes an I-beam and a bracket consisting of an angle and a latch made in the form of a plate with a cutout in the shape of a brand. The latch is welded to the corner, and the corner to the upper chord of the end beam. The I-beam is also welded to the workshop column. The latch, holding the end beam or balance beam on the crane runway, does not prevent their movement along the crane rail, which is necessary to perform operations for joining the main beam to the end beam or to attach the balance beam to it.
The end beam (or balance beam) is installed on the crane runway according to the above scheme as follows. First, an I-beam fixture along with brackets is attached to the columns of the workshop above the crane runways. Then the end beam is lifted with a mounting crane and installed on the crane runway. Without removing the sling, the corner of the bracket is welded to its upper belt (or the body of the balancer), after which the beam is released from the sling. The second end beam of the bridge (or balance beam) is also installed, after which one of the main beams is raised by one of the methods described above and joined to the end beams, then the second. If the main beams rest on the balance beams, then, lifting them one by one, connect their ends to the balance beams, and then raise the end beams and join them with the main beams.
The easiest way to mount crane trucks is to mount the trolley, fully assembled in the lower position, directly on the crane bridge with one or two erection cranes mounted on the side of the bridge. If the characteristics of the existing mobile cranes do not allow this, the trolley is installed by lifting it between the raised half-bridges, as described above.
When the lifting capacity of self-propelled cranes is not enough to lift the trolley in this way, it is mounted in separate assembly units: first, the trolley frame with the movement mechanism and the auxiliary lifting mechanism are installed on the crane bridge, and then the assembly units of the main lifting mechanism are lifted and mounted on its frame.
90. Schemes of installation of mounting beams
91. Mounting beam
1 - reference stick; 2 - overlay; 3 - I-beam; 4 - pipe; 5 - rib; 6 - farm; 7 - outlet block; eight -
chain hoist
After the trolley, the crane cabin is mounted. To do this, cut a hole in the flooring of the working platform of the crane bridge in the center of the cab attachment for the installation crane hook to pass through, install it in the parking lot indicated in the installation diagram. After that, after slinging the cab, it is raised to the design position and attached to the crane bridge.
When for various reasons it is impossible to use tower or jib mobile cranes, assembly units of overhead cranes, especially heavy ones, are lifted with the help of chain hoists suspended from the building frame structures or to mounting beams based on these structures. This method of installation requires mandatory preliminary reinforcement of the building structures, except in cases where this reinforcement is provided in advance when designing the building frame.
One of the ways to lift the assembly units of bridge blocks with the help of building frame structures is that two or four chain hoists are suspended from the tops of two or four columns of the building, respectively, by means of which half-bridges are lifted with a “fish”, or a fully assembled crane bridge, in some cases - along with a trolley secured to the bridge so that it does not move when it is lifted. With such a mounting scheme, the running threads of the chain hoists are directed down along the columns, where the outlet blocks are tied, and through them to the winches located behind the workshop or inside the workshop at a distance from the installation site. The disadvantages of this method are the need for a large number of rigging equipment and winches, as well as ensuring the stability of the columns against forces that they are not designed for. Therefore, this method is rarely used. Sometimes chain hoists are suspended from two adjacent trusses, between which spacers are placed.
The most widely used method of lifting assembly units of overhead cranes with the help of chain hoists suspended from mounting beams based on two adjacent farms 5 (Fig. 90, a), or on two auxiliary beams in (Fig. 90.6), which are based on neighboring farms. With the help of mounting beams, which are also called repair and assembly beams (since they are used to lower and raise assembly units of cranes during their repairs in existing workshops), up to 60% of all overhead cranes of metallurgical workshops are mounted. Much more often, the first variant of the specified method is used, when the beam rests directly on the roof trusses of the workshop along the longitudinal axis of the span.
92. Scheme of the chain hoist of the mounting beam
1 - movable block clip; 2 - poly branch, spasta; 3 - fixed block clip; 4 - mounting beam; 5 - outlet block; 6 - column
93. Scheme of lifting a half-bridge using a chain hoist suspended from a mounting beam
1 - roof truss; 2 - fixed block clip; 3 - ropes; 4 - movable block clip; 5 - sling; 6 - lining; 7 - half bridge
Currently, there are a large number of beams of various designs, of which the most common are I-beams (from one or two tees), box-shaped (from a sheet) sections, as well as lattice beams: two side walls of such a beam are lattice trusses.
On fig. 91 shows a general view and installation diagram of a mounting beam made of two I-beams, connected by strip overlays and reinforced with ribs. The chain hoist is suspended from a pipe fixed on the upper shelves of the I-beams and inside of which a wooden round timber is inserted. The beam is mounted on the ridges of the trusses with the help of support tables.
The carrying capacity of the mounting beams is from 30 to 160 tons, the length (most commonly used) is 6 and 12 m.
Unified beams for the repair and installation of overhead cranes of ferrous metallurgy enterprises have a design similar to that given above. Their carrying capacity is 50, 70 and 100 tons, the scheme of their chain hoists and the direction of the running thread are shown in fig. 92.
The chain hoist suspended from the mounting beam is used to unload assembly units from vehicles on which they are delivered to the mounting area.
Depending on the load capacity of the mounting beam and the mass of the crane assembly units, the main beams, half-bridges, fully assembled bridges (with their subsequent turn in a horizontal plane above the crane tracks), as well as overhead crane trolleys (Fig. 93) are lifted with the help of chain hoists.
Since the mounting beams are installed along the axis of the span, the end beams or balance beams are lifted onto the crane tracks with the help of two chain hoists suspended from the tops of the opposite columns of the workshop building.
Fig. 94
1 - mounting beam; 2 - design position of the half-bridge; 3, 7 - mounting traction mechanisms; 4, 13 - chain hoists; 5 - design position of the end beams; b - initial position of the end beam: 8 - initial position of the half-bridge; 9 - the initial position of the cart; 10 - temporary fixing device; 11 - outlet block; 12 - sleeper flooring; 14 - brace nz hemp rope; 15 - intermediate position of the half-bridge
At the beginning, pulley blocks are lifted and attached to the columns of fixture 10 for temporarily fixing the end beams on the crane tracks (see above). Then they lift and install the end beams, using one of the chain hoists as a load, and the other as a guy. After that, the half-bridges are lifted with a chain hoist with their turn in a horizontal plane and joined with the end beams (one of the half-bridges is conventionally not shown in the figure).
Having assembled the bridge, it is taken aside by two mounting traction mechanisms, after which the trolley is raised above the level of the trolley rails with a chain hoist and, having rolled the bridge under the trolley with the help of traction mechanisms, lower it onto the rails. Then the cabin and other elements of the crane are mounted. The block diagram is shown in fig. 92 the fixed pulley block is tied to the upper part of the column, the running thread is directed along the column down and through the outlet block And to the winch.
Fully assembled installation of overhead cranes by conveyor method. This method, in which the overhead cranes are completely assembled in the lower position and then lifted and installed on the runway using the equipment of the conveyor line for the assembly and installation of building roof blocks, is the most progressive and gives the greatest effect with a large amount of work on the installation of cranes on site. . The conveyor method allows you to organize in-line assembly of nets with a high degree of installation readiness, including the implementation of the maximum amount of electrical installation and commissioning work in the lower position, and therefore, to minimize the volume and duration of work performed at height after the crane is installed on the crane runways.
A prerequisite for the application of this method is the installation of overhead cranes during the construction of the workshop building, since in order to move, lift and install fully assembled overhead cranes on the crane runways, equipment is needed that can be used to carry out similar operations with roofing blocks, i.e. lifts, jib rail cranes, portals, etc.
On fig. 95 shows a scheme for organizing the installation of overhead cranes by a conveyor method using a jib rail crane 1 (intended for the installation of floor blocks of the workshop building) to move a fully assembled overhead crane 2 from the pre-assembly site to the span in which it should be installed, as well as to lift the crane and installing it on iodine crane tracks.
The assembly units of cranes supplied for installation are unloaded from vehicles and laid out on a storage site using one or two pipelayers, which then move the crane elements to the assembly site in the area of the crawler crane. With this crane, the end and main beams are installed on the assembly stand and the crane trolley on the bridge after its assembly. The sequence of operations for the assembly and alignment of the bridge is described above. The assembled overhead crane is rolled to the other end of the stand in the area of the rail crane with the help of an electric winch. Electrical work is carried out here, after which the overhead crane is transferred to the stand and for cabin installation by a rail crane. Using a traverse, a crane operator's cab and a cab for servicing trolls are mounted with a truck crane, mounting cradles and ladders are hung.
At the same stand, the crane and trolley movement mechanisms are tested, and the chain hoists of the lifting mechanisms are stocked.
95. Scheme of organizing the installation of overhead cranes using a conveyor method using a jib rail crane 1 - rail crane SKU-1500R; 2 - fully assembled pavement edges; 3 - truck crane; 4 - crawler crane; 5 - site for the assembly of cranes; 6 - electrical installation site; 7 - pipelayer; 8 - platform for storing crane elements; 9 - mounting traction mechanism; 10 - safety rope; 11, 12 - stands
96. Scheme of organization of the conveyor method of installation of overhead cranes
using the portal t - pre-assembly platform; 2 - crawler cranes; 3 - fully assembled overhead crane; 4 - portal; 5 - polygon for assembly of blocks of coverings of the workshop
Then, with a rail crane, the finally assembled overhead crane is moved to the span of the workshop building and installed on the crane runways, lashing is performed, after which the overhead crane is moved inside the workshop by two traction assembly mechanisms 9.
Other variants of the described method of installation of overhead cranes are also used, which mainly depends on the equipment for lifting and moving roof blocks and which is used when installing overhead cranes. On fig. 96 shows a diagram of the organization of the conveyor method of installation of overhead cranes using a portal, on which blocks of building coverings are moved from polygon 5 to assemble these blocks to a given span of the workshop.
In this case, on the other side of the portal tracks from the landfill, a pre-assembly site is arranged, on which, with the help of two crawler cranes and mounting traction mechanisms, all assembly work is performed, including the installation of a fully assembled trolley on the crane bridge. Electrical work is also carried out here and mechanisms are tested, pulley blocks are stocked, after which the fully assembled crane is lifted by caterpillar cranes and installed on a portal, which is moved to a given span of the workshop. Having docked the rails of the portal with the crane rails of the workshop, the crane is moved into the span using mounting traction mechanisms.
Installation of systems of lubricating crane mechanisms. Lubrication systems are mounted in accordance with the drawings, marking schemes and manufacturer's instructions.
The installation of individual lubrication systems consists in checking the cleanliness of the inner surface of the bearing housings, the serviceability of the oilers, installing them in place and filling them with lubricant.
Centralized lubrication systems are mounted in the following sequence: - install and attach to the supporting surfaces a lubricating hand pump (lubrication station) and feeders; - install and connect the nodes of the main pipelines, the branches from them to the feeders and the branches from the feeders to the lubricated points; – fill pipelines with lubricant; - Set up and test the system.
Before installing the system, it is necessary to make sure that the pump and feeders are working, as well as that the inner surface of all pipeline elements is clean (no dirt, rust). In most cases, manufacturers supply all elements of lubrication systems completely ready for installation in place.
However, if, upon acceptance for installation, dirt or rust is found on the inner surface of piping assemblies and bends, they must be washed and pickled in baths. Etching is also mandatory after welding to remove the scale that forms on the inner surface of the pipeline in the welding zone.
Etching is carried out in solutions of sulfuric, hydrochloric or phosphoric acids. Etching in solutions of sulfuric or hydrochloric acids consists of the following operations: etching itself, washing, neutralizing the remains of the etching solution, washing, drying and lubricating the etched surfaces. For etching, use 20% solutions of sulfuric acid at a temperature of 50-80 ° C or hydrochloric acid at a temperature not exceeding 40 ° C, since at a higher temperature, the release of hydrogen chloride vapors from hydrochloric acid baths increases. The etching time depends on the condition of the inner surface of the pipeline assemblies and outlets, on the temperature of the solutions and can be from 2 to 24 hours. Sometimes etching is carried out in a mixture of acid solutions of the following composition: sulfuric acid - 60 g per 1 liter of solution, hydrochloric acid - 40 g / l, urotropine - 6 g / l, table salt - 25 g / l at a temperature of 40-50 ° C.
The quality of cleaning is controlled visually. If the surface has not been sufficiently cleaned, then spots and separate areas of undissolved oxides are visible on it; a well-cleaned surface has a steel-gray color, and an over-etched surface is black.
After etching, the knots and branches are removed from the solution and kept above the bath for the solution to drain, and then transferred to a bath with water, in which they are washed, then transferred to a bath with a 3-5% soda or lime solution to neutralize the residues of the pickling solution in within 1 hour
After neutralization, the products are washed in a hot water bath heated to 80-90 °C and dried in air.
The dried etched surface must be lubricated with oil, as it again corrodes very quickly. For this purpose, pipeline assemblies and outlets are immersed in an oil bath, and after being removed from it, they are placed on racks in an inclined position for oil to drain for 2-3 hours.
All of the above operations are performed without interruption, at the end of their ends of the nodes and branches are closed with plugs.
Etching in phosphoric acid solutions differs from that described above in the absence of such operations as washing, neutralizing and lubricating the etched surfaces with oil.
Piping units and bends previously cleaned of contaminants are first pickled in a 15-20% solution of phosphoric acid at a temperature of 50-60 ° C for 6-12 hours (depending on the condition of the internal surface of the products), checking the quality of cleaning in the same way as and when pickling in solutions of sulfuric or hydrochloric acid, and then transferred to a bath with a 2% solution of the same acid, after draining the remains of the pickling solution into a bath with a 15-20% solution. In a 2% solution of phosphoric acid, a thin phosphate film forms on the surface of steel products after pickling, which passivates (covers) the metal surface and protects it from corrosion for several months. In a bath with such a solution, the piping units and outlets are kept for 1-2 hours at a temperature of 50 ° C, after which they are removed from the solution, allowed to drain back into the bath, laid on a rack and dried with compressed air, previously cleaned of moisture and oil and, if possible, heated (to speed up drying). Then the ends of the products are closed with plugs to prevent the ingress of contaminants, as well as water, which destroys the protective film. The surface etched and covered with a passivating film is dark gray with a barely noticeable greenish tint.
Lubricating feeders for which the warranty period has not expired and no defects were found during external inspection are put in place and fixed to the crane structure with screws that tightly attract the feeder to the support.
If the warranty period has passed, but no defects were found either, the feeders are tested for tightness with mineral oil at the test pressure indicated in the passport for 2 minutes in each of the extreme positions of the pistons.
In this case, oil must not leak through the seals of the rods and plugged connecting holes in the housings, and its leakage through any of the outlets to the lubricated points must not exceed three drops per minute. Feeders must operate and deliver the prescribed amount of lubricant at a pressure difference in the main lines of not more than 1 MPa and a number of piston strokes of at least 6. The movement of pistons and spools must be smooth, without jamming along the entire stroke length. The test and check for operation is carried out by injecting lubricant into each line in turn. Feeders that do not pass the test are sent for repair, and new ones are installed instead.
Pipelines of systems are assembled from units and bends manufactured at the factory. When the manufacturer supplies the pipelines in the form of straight pipe sections and pipeline parts separately, the installers themselves manufacture the main pipeline assemblies and bends from pre-etched pipes.
Pipeline connections are made mainly on conical pipe threads using union nuts and fittings (angles, tees, couplings). The use of sealing agents in these compounds in the form of whitewash, red lead and tow is not allowed; they are collected on nitrolac of the brand NTs or bakelite varnish of the brand LBS. Often, instead of squares, pipe bending is used, and instead of tie-in tees, performed by welding; so, the branches from the mains to the feeders and from the feeders to the lubricated points in many cases are made curved, and the branches are connected to the mains through threaded fittings welded to the latter.
Pipelines are also connected by welding, but it is necessary that the welded joint is between two threaded ones. This allows, after assembling the pipeline, to dismantle the section with a welded joint and pickle it. If the welded joint is made in a socket or with a sleeve welded on the outside of the joint, then etching can be omitted after welding.
Having installed the system, the pipelines are blown with compressed air to remove solid particles that got inside during the assembly of the joints, and then they are filled with lubricant using a pump, supplying the lubricant first through one main pipeline, and then through the other. One of the main requirements in the implementation of this operation is the removal of air from pipelines. Air entering the system interferes with normal operation. To do this, during filling, the opposite end of the pipeline is opened and only after 0.5 kg of lubricant has exited it is closed.
As the pipeline is filled, the outlets to the feeders and feeders are charged with lubricant, for which the plugs installed on these outlets are removed in turn before purging. The branches are connected to the feeders only after 50-100 g of lubricant comes out of each branch. The feeder is considered charged when 10-20 g of lubricant comes out of it. After that, the feeder is closed with stoppers. The outlets from the feeders to the lubricated points are charged as follows. Branches are disconnected from feeders and lubricated points, blown with compressed air and filled with lubricant using a hand pump until 50-100 g of contaminated lubricant comes out of the free end of each branch, which is removed. After that, the outlet is installed in place.
Having filled the system, they proceed to its adjustment, which consists in checking the operation of the feeders and determining the pressure necessary for their operation. The actuation of the feeders is checked by alternate injection of lubricant into both lines.
When injecting into the first line, all rods must be in the upper position, when injecting into the second line, in the lower position. In case of inconsistency in the position of the rods, the outlets from the main pipelines to a part of the feeders are interchanged so that the rods of all feeders, when the lubricant is injected into one of the two lines, are in the raised or lowered position.
The pressure at which the system must operate is determined by the pressure gauge at the time of operation of the most remote feeder plus 0.5 MPa. After checking the operation of the feeders and determining the operating pressure, the pipelines are subjected to a hydraulic test with a trial pressure. To do this, a high-pressure pump is used, with which the lubricant is pumped alternately into the first and second main pipelines. The test pressure in each pipeline is 1.2 of the working pressure, it is maintained for 20-30 minutes. During this time, the pressure drop should not exceed 10%.
Installation of lifting ropes. A responsible operation during the installation of cranes is the reeving of ropes on lifting mechanisms, in which the following requirements must be observed: ensuring the safety of the rope during its installation; prevention of unnecessary internal stresses caused by the conditions of reeving; correct initial laying of the rope on the drum of the lifting mechanism.
Damage and the formation of additional stresses in the rope can occur if it is not unwound from coils or drums. When reeving, it is necessary to follow the order of laying the rope, one end of which should sequentially go around all the rollers in block clips and then be attached to the drum. The second end is also attached to the drum or to the upper block clip. The rope can be guided manually or by the substitution method.
On fig. 97 shows the reeving of the chain hoist of the main lifting mechanism of an overhead crane by the substitution method. The drum or reel with rope 1 is installed under an overhead crane on supports in which they can rotate freely. The movable holder of the chain hoist 5 with a hook suspension is fixed in the lower position along the axis of the crane. Also, an electric winch 6 is installed under the crane, on the drum of which a thin rope is wound.
This rope is manually passed through all the pulley rollers and connected to the end of the project rope wound on drum 1. Then, turning on the electric winch, a thin rope is passed through all the rollers in the opposite direction, but with the project rope, which thus replaces the thin rope in the chain hoist rope.
97. Scheme of reeving of a chain hoist
a - scheme of organization of work; b - stocking scheme; 1 - drum with rope; 2 - fixed block clip; 3 - drum of the lifting mechanism; 4 - overhead crane trolley; 5 - movable block clip; 6 - electric winch
When reeving, it is important to accurately determine the length of the rope, otherwise the hook will not rise to the desired height, or will not reach its lower position.
If the hook according to the project falls below the level of the floor of the workshop (in the presence of recessed rooms), the length of the rope must be increased by the distance from the floor to the lower position of the axis of the movable clip, multiplied by the multiplicity of the crane hoist.
When reeving new ropes, the chain hoist often twists. Twisting is eliminated in two ways: by pre-rolling the rope to its full length in one straight line when reeving or by unwinding the chain hoist.
In the second method, the load is raised, the mass of which is 30% of the mass of the largest load, by 150-200 mm and the chain hoist is allowed to spin freely, holding only the load from acceleration. At the same time, the number of revolutions of the lower block clip is counted until the chain hoist stops rotating.
After the rope is fixed on the drum, the hook is raised and lowered several times, thereby evenly distributing the twist along the entire length of the rope.
Features of the installation of metallurgical cranes are due to the design features of bridges, bogies and mechanisms for performing special technological operations. The sequence and rules for performing all assembly operations during the installation of metallurgical cranes are detailed in the instructions of manufacturers, therefore, the procedure for installing enlarged assembly units of these cranes is considered here.
When mounting muldloading cranes after assembling the bridge on crane tracks (or lifting the assembled bridge), the frame of the main trolley with the chassis and mechanisms for moving, turning and lifting the column is lifted onto the bridge. At the same time, the lower part of the main trolley is assembled, starting from the control cabin. The cabin is installed on the working platform on linings. Before installation and fixing on the control platform, the column is cleaned of preservative coating and checked for straightness and absence of nicks; the curvature of the faces of the column should not exceed 1 mm over a length of 1 m. After the column is fixed on the site, a frame with mechanisms is inserted into it and installed along the swing axis. Then they assemble the trunk with a mouthpiece.
After assembling the lower part of the main trolley, a shaft is put on the column using a self-propelled crane or chain hoists tied to the frame of the main trolley. The shaft with the column is fixed in a vertical position (for stability) with braces or racks. Then, a traverse with a suspension of the column lifting mechanism is put on and fixed on the head of the column.
After that, the shaft assembly with the column and the cabin is lifted and fixed to the frame of the main bogie.
The shaft is lifted with chain hoists suspended from the trolley frame or mounting beam, or by a column lifting mechanism.
The installation of foundry cranes differs from the installation of general-purpose cranes in that the main bridge is first assembled on the crane tracks, then the auxiliary one, and then the carts are mounted. Bridges of heavy foundry cranes are assembled on crane tracks from half-bridges or individual elements, when the mass of the elements (balancing carts, bridge beams) and the load capacity of the existing mounting mechanisms do not allow them to be enlarged into half-bridges. Such cranes are most often mounted using chain hoists suspended from mounting beams. For the same reason, the main bogies of heavy casting cranes are mounted on the crane bridge from enlarged assembly units, and the auxiliary bogies are assembled as a whole, in the form in which they come from the manufacturer. For slinging the main bogies of foundry cranes, a fixture of the Gipromallurgmontazh Institute is often used, consisting of a traverse, which, through four sliding rods, is pivotally connected to two shoes placed under the middle beam of the bogie frame.
When installing cranes for stripping ingots after assembling the bridge and installing the trolley on it, the shaft is suspended and fixed to it, pre-assembled with a cabin, platforms and stairs into one enlarged mounting element.
Specific to these cranes is the attachment of the ingot ejection mechanism with tongs, which, as a rule, comes from the factory in assembled form. Laid in a horizontal position near a special repair pit 4.6 m deep, this mechanism is lowered into the pit using a chain hoist suspended from a beam on the trolley frame, or the main lift mechanism.
If the ejection mechanism arrives disassembled, it is assembled in a horizontal position next to the repair pit and lowered into it. After that, the crane bridge and the trolley are installed above the repair pit so that the ejection mechanism can be lifted and brought into the shaft directly from the pit without moving it in a horizontal direction.
If by this time the installation of the main lifting mechanism of the crane trolley has not yet been completed, then the ejection mechanism is lifted with the same chain hoist with which it was lowered into the repair pit. Having lifted the mechanism along the guides of the mine, it is temporarily fixed and further work is performed after the installation of the main lifting mechanism and electrical work is completed.
With the main lift mechanism running, the ejection mechanism is mounted as follows.
Hoisting ropes are attached to the drum, they go around the blocks of the ejection mechanism and are preliminarily fixed on its balancer. The ropes of the tongs control mechanism are passed through the blocks, fixed on the levers of this mechanism and on the drum. Then, the ejection mechanism from the pit is raised to the lower design position (with the maximum opening of the tongs) and temporarily fixed in the shaft on two beams brought under the protruding parts of the cartridge. After that, the released ropes are pulled and again fixed on the balance bar and levers (without cutting off their ends). Having raised the ejection mechanism to the upper design position (with a minimum opening of the tongs), the ropes are attached to the balancing counterweight of the tongs control mechanism.
The installation technology of well (tong) valves is similar to the technology of installation of cranes for stripping ingots.
The dismantling of overhead cranes is carried out in most cases using self-propelled jib cranes or chain hoists suspended from mounting beams. Mounting masts are used much less frequently for this purpose (for the same reasons that they are rarely used for mounting cranes).
It is promising to use hydraulic hoists designed by Giprotekhmontazh for the dismantling of overhead cranes.
Cranes may be dismantled only if a specially designed PPR is available.
Prior to the start of dismantling, preparatory measures are carried out, including: - preparation of the required lifting mechanisms and equipment, including the installation of winches, the linkage of chain hoists and pull-off blocks, the installation of devices for temporarily fixing end beams or balancers on crane tracks, etc. ; - preparation and installation of scaffolding tools necessary for dismantling the crane; - fencing the hazardous area of work and preparing the site for placing the removed assembly units of the crane.
Having installed shoes under the wheels of the crane and trolley to prevent their spontaneous movement,
and having de-energized the mechanisms of the crane, they begin to disassemble it.
First, they sling and remove the trolley from the crane bridge. If the carrying capacity of the existing mechanisms and equipment is less than the mass of the trolley assembly, then it is disassembled into the minimum required number of elements and removed one by one.
For the same reasons, the crane bridge is removed entirely or disassembled into two half-bridges or another number of elements in accordance with the PPR.
Bridge disassembly operations are performed in the reverse order of its assembly.
The mounting plates are removed by gas cutting, having previously lashed the main beam (or half-bridge), which is to be removed first, and temporarily securing the end beams or balance beams on the crane runways.
The lowering of half-bridges, individual beams or a complete bridge is carried out according to the schemes opposite to those adopted during the installation of the crane.
To Category: - Mounting of loader cranes
The size of the galleries is regulated by the Crane Rules. The width of the free passage through the gallery should be:
a) for cranes with a transmission drive - at least 500 mm;
b) for cranes with non-transmission or manual drive - at least 400 mm.
For the same cranes on the galleries intended for the location of trolley wiring, the width of the passage between the railings and the devices supporting the trolleys, as well as the current collectors, must be at least 400 mm.
The requirements of the Rules for Cranes do not apply to the overhead crane gallery located on the side of the current supply, if the current supply to the electrical equipment of the trolley is made by a flexible cable. The console holding the cable can cross the bridge gallery along the entire width. The access hatch to the bridge deck of such a crane must be equipped with a lock that automatically relieves tension from the flexible cable when it exits to the bridge deck.
The distance from the end railing of the crane bridge to the protruding parts of the cargo trolley when it is in the extreme position is not regulated. This distance to increase the service area of the crane is sometimes taken to be less than 400 mm. All these requirements also apply to gantry cranes and mobile jib cranes.
Cabin-operated overhead cranes (except for single-girder and overhead cranes) must be equipped with cabins (platforms) for servicing the main trolley wires and current collectors, if they are located below the deck of the bridge gallery. The hatch for entering this cabin from the bridge deck must be equipped with a lid with a lock.
The dimensions of the cabin for servicing the main trolleys and their pantographs are not regulated and are usually taken as 1000 x 1400 (PTO Komsomolsk-on-Amur plant) with a height of at least 1800 mm. The cabin area should not be less than 800 x 800 mm. The cabin must be fenced with a railing at least 1 m high with a continuous filing along the bottom to a height of 100 mm. With a flexible current lead, the sites are sometimes not arranged.
The crane bridge must be fenced on four outer sides (along the perimeter) with railings 1 m high with a solid fence to a height of at least 100 mm to prevent falling tools or parts during inspection and repair of crane mechanisms and electrical equipment.
Railings are not installed on the bridge galleries and end beams from the bogie side.
In this regard, it is dangerous to be on the bridge of a crane made of lattice trusses, in which the gallery flooring is located at the level of the trolley rails, since it is possible to fall into the span between the trusses. Cases of people falling off a crane bridge have been recorded exclusively on lattice truss cranes. In addition to the noted drawback (lack of proper fencing of the galleries), on such cranes the passage along the deck is constrained due to the location of the movement mechanisms on it, which also poses a danger to the operating personnel. For box girder cranes, the deck of the gallery is located below the level of the trolley rails, so passage through such galleries is not dangerous.
To prevent accidents on cranes of old designs, where passage through the gallery is constrained, it is necessary to arrange bypass platforms at the locations of the electric motor and gearbox of the bridge movement mechanism or walkways with railings. Care should also be taken to ensure that the worker's feet do not slip on the floor when crossing.
The installation of railings along the bridge from the side of the bogie causes difficulties in the maintenance and repair of the bogie mechanisms, since in this case it is necessary to climb over the railing.
The crane trolley must be protected from the end sides by a railing 1 m high with a continuous filing along the bottom to a height of 100 mm. Railings on one of the longitudinal sides of the trolley should be installed if there is no gallery along the crane bridge on that side, for example, with a flexible power supply to the trolley.
For bogies and end beams, it is allowed to reduce the height of the railing if the dimensions of the building do not allow the installation of a railing with a height of 1 m.
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2.17.1 Galleries, platforms and stairs to provide safe access to control cabins, electrical equipment, safety devices, mechanisms and metal structures of cranes that require maintenance must comply with these Rules and other regulatory documents.
The design and location of the gallery, platforms and stairs on the cranes and in the places where the cranes are installed should be determined by the projects for the manufacture and / or installation of cranes.
2.17.2. The crane must have a convenient entrance from the ground and access to the cab. Overhead cranes must also have a safe exit to the crane trolley. For single girder overhead cranes and overhead double girder cranes, galleries or platforms on the crane are not required if there is a repair platform for the crane.
2.17.3. For bridge-type cranes and mobile jib cranes, if there is a gallery intended for servicing electrical equipment and mechanisms, the width of the free passage through the gallery should be:
a) for movement mechanisms with a central drive - at least 500 mm;
b) for movement mechanisms with a separate drive - at least 400 mm.
For the same cranes on the gallery intended for the location of the trolleys, the width of the passage between the railings and the devices supporting the trolleys, as well as the current collectors, must be at least 400 mm.
2.17.4. In the spans of buildings where overhead traveling cranes with a classification (mode) group of A6 or more according to ISO 4301/1 are installed, as well as on racks for cranes (except for single-girder cranes with electric hoists), galleries must be arranged for passage along the crane track from both sides of the flight.
Galleries for passage along the crane track must be provided with railings on the side of the span and on the opposite side in the absence of a wall. A gallery on an open overpass can only be equipped with railings from the outside (opposite to the span).
The width of the passage (clearly) along the gallery must be at least 500 mm, the height - at least 1800 mm.
At the locations of the columns, a passage must be provided on the side or in the body of the column with a width of at least 400 mm and a height of at least 1800 mm. It is not allowed to leave an unenclosed section of the gallery near the columns.
When arranging a passage inside the column 1000 mm before approaching it, the width of the passage along the gallery should be reduced to the width of the passage in the column. Each gallery must have exits to the stairs at least every 200 m.
2.17.5. Repair sites should provide convenient and safe access to machinery and electrical equipment.
If the distance from the floor of the repair site to the lower parts of the crane is less than 1800 mm, the door to enter the repair site must be equipped with a lock and an automatic electric lock that relieves voltage from the main trolleys of the repair site.
Instead of the device of stationary repair sites, the use of mobile sites is allowed.
2.17.6. Overhead cranes controlled from the cabin (except for single-girder cranes with electric hoists) must be equipped with cabins (platforms) for servicing the main trolleys and pantographs, if they are located below the deck of the crane gallery.
The hatch for entering the cabin for servicing the main trolleys from the bridge deck must be equipped with a cover with a device for locking it with a lock.
The cabin for servicing the main trolleys must be fenced with railings with a height of at least 1000 mm with continuous lining at the bottom to a height of 100 mm.
2.17.7. When arranging in the decking of walk-through galleries of repair and other areas of hatches for entry, their size should be taken at least 500 × 500 mm; the hatch should be equipped with an easily and conveniently opening lid.
The angle between the hatch cover in the open position and the flooring should be no more than 75 °.
2.17.8. To enter the control cabin of an overhead, mobile jib crane, as well as a cargo electric trolley moving along an overhead crane track, a landing site with a stationary ladder should be arranged.
The distance from the floor of the landing site to the lower parts of the ceiling or protruding structures must be at least 1800 mm. The floor of the landing area must be located on the same level as the floor of the cabin or vestibule, if the cabin has a vestibule. The gap between the landing area and the threshold of the cabin door (lobby) when the crane stops near the landing area must be at least 60 mm and not more than 150 mm.
It is allowed to arrange a landing site below the level of the cabin floor, but not more than 250 mm, in cases where, when the landing site is located on the same level with the cabin floor, the height clearance (1800 mm) cannot be maintained, as well as when the landing site is located at the end of the building and the impossibility of maintaining the specified gap between the cabin threshold and the landing site.
When arranging a landing site at the end of the crane (rail) track below the cabin floor level, it is allowed to run over the landing site (but not more than 400 mm) with fully compressed buffers. At the same time, the gap between the landing area and the lower part of the cabin (vertically) should be within 100-250 mm, between the cabin and the landing platform fence - within 400-450 mm, from the side of the entrance to the cabin - within 700-750 mm.
2.17.9. Entrance to the control cabin of an overhead crane through the bridge is allowed only in cases where direct entry into the cabin is not possible for structural or production reasons. In this case, the entrance to the crane must be arranged in a specially designated place through the door in the bridge railing, equipped with an electrical interlock and sound alarm.
For magnetic cranes, the entrance to the control cabin through the bridge is not allowed, except when the trolleys supplying the cargo electromagnet are fenced or located in a place inaccessible to contact and are not switched off by an electric blocking of the crane entrance door.
2.17.10. The flooring of galleries, platforms and walkways must be made of metal or other durable materials that meet fire safety requirements. The flooring should be arranged along the entire length and width of the gallery or platform.
Metal flooring must be made in such a way as to exclude the possibility of slipping of the legs (expanded steel, corrugated, perforated sheets, etc.). In the case of decking with holes, one of the hole sizes must not exceed 20 mm.
2.17.11. Galleries, platforms, walkways and stairs arranged at the locations of trolleys or uninsulated live wires, regardless of the presence of entrance blockages, must be fenced to prevent accidental contact with trolleys or uninsulated wires.
2.17.12. Platforms and galleries intended for access and maintenance of cranes, end beams of bridge-type cranes must be fenced with railings with a height of at least 1000 mm with a continuous fence at the bottom to a height of 100 mm and an intermediate link located in the middle of the opening.
Railings and barriers at the bottom should also be installed on the end sides of the bridge-type crane trolley, and in the absence of a gallery, along the crane bridge and on the longitudinal sides of the trolley.
On the end beam and trolley of an overhead or mobile jib crane, the height of the railing can be reduced to 800 mm if the dimensions of the building do not allow the installation of a railing with a height of 1000 mm.
Racks on the landing site, to which the railing or landing site fastening structures are attached, located at a height of more than 1000 mm from its flooring, must be at least 400 mm from the cabin.
End beams and cargo trolleys of bridge-type cranes, in which the lifting mechanism is an electric hoist, railings and fences may not be equipped.
2.17.13. Portal cranes must be provided with a safe entrance from the ladder of the portal to the platform located around the head of the portal in any position of the rotary part of the crane.
The height from the flooring of this platform to the lower protruding elements of the turntable must be at least 1800 mm. The entrance from the portal to the rotary part of the crane must be possible in any position of the rotary part.
2.17.14. Ladders for access from the floor to platforms and galleries of bridge-type cranes, tower and gantry cranes must be at least 600 mm wide. The width of stairs located on the crane, with the exception of stairs with a height of not more than 1500 mm, must be at least 500 mm.
Ladders with a height of less than 1500 mm, located on a crane, as well as stairs for entering from the cab to the gallery of a bridge-type or mobile cantilever crane, can be made at least 350 mm wide.
2.17.15. The distance between the steps should be no more than 300 mm for steeply inclined stairs, 250 mm for inclined landing ladders and 200 mm for inclined landing ladders of tower cranes.
Step steps must be maintained along the entire height of the stairs. The steps of steeply inclined stairs must be at least 150 mm from the crane metal structures.
2.17.16. Ladders for access from the floor to landing, repair sites and galleries for passage along the crane track must be located so as to exclude the possibility of people on them being pinched by a moving crane or its cabin.
2.17.17. Inclined stairs must be provided on both sides with railings with a height of at least 1000 mm relative to the steps and have flat metal steps with a width of at least 150 mm, which exclude the possibility of slipping.
2.17.18. On steep stairs, starting from a height of 2500 mm from the base of the stairs, guards in the form of arcs should be arranged. The arcs must be located at a distance of at least 800 mm from each other and connected to each other by at least three longitudinal strips.
The distance from the ladder to the arc should be at least 700 mm and not more than 800 mm with an arc radius of 350-400 mm. Arc fencing is not required if the staircase passes inside a lattice column with a cross section of no more than 900x900 mm or a tubular tower with a diameter of no more than 1000 mm.
The device of steeply inclined stairs above the hatches is not allowed. With a ladder height of more than 10 m, platforms should be arranged every 6-8 m. When stairs are located inside a tubular tower, such platforms may not be arranged.
2.17.19. Ladders to enter the platforms for servicing jib cranes must be stationary, folding (retractable) with a handrail height at the entrance to the platform of at least 150 mm.
Handrails must be covered with a low heat-conducting material.
Steps must be at least 320 mm wide in increments of 250 to 400 mm. The height from the surface of the ground or platform to the first step should be no more than 400 mm.
GOST 32576.5-2013
INTERSTATE STANDARD
CRANES
Means of access, fencing and protection
Part 5
Overhead and gantry cranes
Cranes - Access, guards and restraints. Part 5: Bridge and gantry cranes
ISS 53.020.20
Introduction date 2015-06-01
Foreword
The goals, basic principles and basic procedure for carrying out work on interstate standardization are established in GOST 1.0-92 "Interstate standardization system. Basic provisions" and GOST 1.2-2009 "Interstate standardization system. Interstate standards, rules, recommendations for interstate standardization. Rules for the development, adoption , updates and cancellations"
About the standard
1 DEVELOPED BY RATTE Closed Joint Stock Company (RATTE CJSC)
2 INTRODUCED by the Federal Agency for Technical Regulation and Metrology
3 ADOPTED by the Interstate Council for Standardization, Metrology and Certification (Minutes of November 14, 2013 N 44-2013)
Voted to accept:
Short name of the country according to MK (ISO 3166) 004-97 | Abbreviated name of the national standards body |
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Ministry of Economy of the Republic of Armenia |
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Kyrgyzstan | Kyrgyzstandart |
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Moldova-Standard |
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Rosstandart |
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Tajikistan | Tajikstandart |
4 By order of the Federal Agency for Technical Regulation and Metrology dated August 22, 2014 N 942-st, the interstate standard GOST 32576.5-2013 was put into effect as the national standard of the Russian Federation from June 1, 2015.
5 This standard corresponds to the international standard ISO 11660-5:2001* "Cranes - Access, guards and restraints. Part 5: Bridge and gantry cranes".
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* Access to international and foreign documents mentioned in the text can be obtained by contacting the User Support Service. - Database manufacturer's note.
Degree of conformity - non-equivalent (NEQ)
6 INTRODUCED FOR THE FIRST TIME
Information about changes to this standard is published in the annual information index "National Standards", and the text of changes and amendments - in the monthly information index "National Standards". In case of revision (replacement) or cancellation of this standard, a corresponding notice will be published in the monthly information index "National Standards". Relevant information, notification and texts are also posted in the public information system - on the official website of the Federal Agency for Technical Regulation and Metrology on the Internet
Introduction
Introduction
This standard is part of a series of standards "Crane. Means of access, fences and protection" and establishes special requirements for the means of access, protection and fences used in the design of overhead and gantry cranes to ensure safety during operation, including maintenance, control maintenance, installation, dismantling and in emergency situations in order to protect personnel from moving parts, falling objects or current-carrying parts.
The standard was developed taking into account the main regulatory provisions of the international standard ISO 11660-5:2001 "Cranes - Access, guards and protections - Part 5: Overhead and gantry cranes" (ISO 11660-5:2001 "Cranes - Access, guards and restraints. Part 5: Bridge and gantry cranes"). The application of the provisions of this standard on a voluntary basis can be used to confirm and assess the compliance of cranes with the requirements of the Technical Regulations of the Customs Union "On the safety of machinery and equipment" (TR CU 010/2011).
1 area of use
This standard contains general requirements for the means of access, fencing and protection of overhead and gantry cranes (hereinafter referred to as "cranes") according to the classification installed in the working position, and regulates the special requirements for the means of access, protection and fencing used in the design of cranes to ensure safety during operation, including maintenance, monitoring of technical condition, installation, dismantling and in emergency situations in order to protect personnel from moving parts, falling objects or current-carrying parts.
The general requirements for the means of access, fencing and protection for cranes are established in the national standards of the states mentioned in the preface as having voted for the adoption of the interstate standard *.
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GOST R 55178-2012
This standard applies to all new overhead and gantry cranes manufactured one year after its approval. The standard is not intended to require the replacement or upgrading of existing equipment. However, when upgrading equipment, the requirements for its properties should be revised in accordance with this standard. If the fulfillment of the requirements of the standard during modernization causes significant changes in the design, then the possibility and necessity of bringing the equipment in accordance with the requirements of this standard should be determined by the manufacturer (designer), and in his absence - by the organization performing its functions, and subsequent changes should be made by the owner (user). ) within one year.
2 Normative references
This standard uses references to the following interstate standards:
GOST 13556-91 Tower cranes. General specifications
GOST 27555-87 (ISO 4306-1-85) Cranes. Terms and Definitions.
Note - When using this standard, it is advisable to check the validity of reference standards in the public information system - on the official website of the Federal Agency for Technical Regulation and Metrology on the Internet or according to the annual information index "National Standards", which was published as of January 1 of the current year, and on issues of the monthly information index "National Standards" for 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 with the corresponding definitions given in GOST 27555, -, as well as the following:
3.1
landing area: A platform permanently fixed on the structures of a workshop or overpass and serving to provide a safe entrance to the crane.
3.2
mobile means of access: Means of access used to perform installation, maintenance or repair of a crane and delivered to the work area only for the duration of the work.
4 Access system
4.1 General
This part of the standard deals with the means of access to cranes moving along overhead or ground tracks, as well as to their elements and assemblies for operation, repair and maintenance.
Safe means of access to all elements of the crane requiring the presence of service personnel for installation, maintenance and operation must be provided.
Access to the crane and its components is generally provided by a system of access means, consisting of stairs, platforms and galleries equipped with railings, and other elements that provide the necessary level of safety for the operating personnel.
4.2 Overhead cranes in buildings or overpasses
4.2.1 Access to the crane landing area
Access to overhead cranes controlled from the cab must be carried out from landing sites permanently fixed on the structures of the workshop or overpass.
Landing floor access ladders and their guardrails must comply with the requirements for access, guardrails and protection for cranes, which are established in the national standards of the states mentioned in the preface as having voted for the adoption of the interstate standard *.
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* In the Russian Federation, GOST R 55178-2012 (ISO 11660-1:2008) "Lifting cranes. Means of access, fencing and protection. Part 1. General provisions"
Recommended means of access to the landing sites, depending on the height of their location, are given in Table 1.
Table 1 - Recommended means of access
The height of the landing site from the floor, m | |
from 1 to 15 inclusive | stairs Inclined stairs Steep stairs Stairs are vertical |
St. 15 to 25 | stairs |
Motorized access means Stairs |
4.2.2 Landing area
4.2.2.1 Access to the crane must be from the landing area. The landing site guards must comply with the requirements for guards installed on the crane. The opening for access to the crane must be equipped with a self-closing door.
4.2.2.2 The crane access door may be:
- hinged, opening inside the landing area;
- sliding in the horizontal or vertical direction.
Opening the hinged door outside the landing area is not allowed.
4.2.2.3 In cases where, when the landing site is located at the same level with the cabin floor, the height clearance cannot be maintained, the levels of the landing site decking and the decking of the corresponding platform on the crane may differ in height by no more than 10 mm when the landing decks are located platform and crane at the same level or from 180 to 250 mm when the crane deck is located above the level of the landing platform (running into it) (Figure 1, c).
c - Clearances when hitting a landing pad
1 - the direction of movement of the crane; 2 - crane platform; 3 - landing site
Figure 1 a) | Figure 1 b) | Figure 1 c) |
180250 (when the crane platform is located above the level of the landing site (collision with it)) |
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Minimum distances between the railings of the crane platform and the landing platform All dimensions in mm |
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Figure 1 - Clearances between the landing site and the crane structure
4.2.2.4 The clearances between the landing site and the crane platform or cabin should be as shown in Figure 1. If the specified clearances cannot be maintained, other measures should be taken to provide an equivalent degree of protection against pinching, shearing and falling from a height.
4.2.3 Alternative crane access system
4.2.3.1 General requirements
An alternative access system (for example, through a bridge) to the cabin of an overhead crane is allowed only in cases where direct entry into the cabin is not possible for structural or production reasons. In this case, the entrance to the crane should be arranged in a specially designated place through the door in the bridge railing.
As a rule, the passage to the crane is carried out by stairs, walkways and galleries fixed on the structures of the workshop or overpass. All stairs, walkways, ramps on the crane bridge and on the crane access galleries, as well as current supply trolleys, must be fenced on all open sides in accordance with the requirements for fences installed on the crane. At the same time, appropriate passages and clearances must be provided (figures 2 and 3). In places where it is not possible to provide the necessary clearances, such as in existing buildings, other measures should be taken to provide an equivalent degree of safety.
Access to the crane bridge and trolleys by stationary vertical ladders is allowed only in cases where the installation of ladders and inclined ladders is not possible.
1 - railing A; 2 - railing B; 3 - cart
Figure 2 - Passage through the gallery of the bridge
1 - railing A; 2 - railing B; 3 - Column; 4 - wall
Figure 3 - Passage to the crane along the gallery in the workshop or on the overpass
NOTE Handrail A can be omitted if 600 mm; railing B can be excluded if 1000 mm or railing A exists. With a distance of 100 mm and 500 mm from the railing to the power components, it is recommended to install two limiters for the knees, dividing the railing into three parts in height. This reduces the risk of feet getting into the danger zone, and also reduces the risk of pinching when moving to a crane in places where there is no special opening in the guards.
4.2.3.2 Crane access control
Access to a working crane for service personnel may be carried out only with the permission of the crane operator (crane operator).
If communication with the crane operator is difficult, consideration should be given to using the "Request permission to land" system, which should inform the crane operator (crane operator) of a request to board a person who needs access to the crane. The request can be made using a light or sound signal with a button on the landing site, as well as using various intercoms.
The factors that necessitate the application of the "Request permission to land" system are as follows:
- speed of movement of the crane;
- visibility of the access point from the crane operator's seat;
- working conditions - insufficient visibility, noise, etc.
4.3 Access to gantry cranes
The general requirements for the arrangement of means of access for gantry cranes moving along overland tracks are the same as for overhead cranes (see 4.2).
When designing means of access to gantry cranes, it should be taken into account that the main risk factors are the risk of hitting or running over people who are near the crane legs or with the trolley. Access ladders to the crane should be located as far as possible so that contact with nearby people is excluded. If this is not possible, then steeply inclined or vertical ladders fixed to the crane metal structure should be used. The distance from the ground to the first arc of the railing of such stairs should be 3 m.
If the gantry crane cabin is located at a height of more than 20 m, you should use the means of access with a drive (elevator, crane hoist). When using powered access means, alternative means of access (stairs) must be provided.
4.4 Access to the cabin located on the crane trolley
If the control cabin is located on a crane trolley (mobile cabin), the means of access to the cabin must comply with the requirements of 4.1-4.3 of this standard.
4.5 Requirements for crane hoists (elevators)
4.5.1 Crane lifts (elevators) must comply with the requirements of GOST 13556.
4.5.2 The lifting capacity of the hoist must be at least 160 kg.
5 Crane maintenance access
5.1 General requirements
Overhead and gantry cranes must have a safe exit to the crane trolley.
When choosing means of access for maintenance and repair of the crane, the following factors should be considered:
- the frequency of the need for access in accordance with the instructions of the crane manufacturer;
- the time required to perform maintenance work;
- the time required to access the service point;
- the time required to perform work at a given point;
- the size of the moved elements.
It is preferable to use fixed means of access (platforms, stairs, etc.). If it is not possible to arrange fixed access means for access to individual crane nodes, it is allowed to use mobile access means.
If a crane is to be used for building maintenance, its design must provide for appropriate passages and special platforms.
5.2 Mobile access devices
5.2.1 The need to use mobile access devices should be determined by the manual for the operation and repair of the crane. The orientation and location in space of the mobile access device should facilitate its use.
5.2.2 The following mobile access tools are recommended:
- towers (forests);
- separate ladder systems;
- lifting platforms with a mechanical drive;
- various cradles, including those suspended on the hook of the crane itself (for example, to inspect the metal structure of the main beams).
Note - the use of portable ladders with a height of more than 2 m does not provide the required level of safety.
5.2.3 Requirements for cradles suspended from a crane hook
5.2.3.1 The cradles must comply with the safety requirements for equipment for lifting people.
5.2.3.2 The dimensions (length and width) of the cradle shall not be less than 0.500.35 m.
5.2.3.3 When choosing the carrying capacity of the cradle, the required number of personnel and the weight of the tool should be taken into account.
5.2.3.4 The operation manual of the cradle and information plates on the cradle shall contain:
- permissible load and number of people in the cradle;
- a way of landing in a cradle;
- warnings about possible risks (eg entanglement in ropes).
5.3 Use of local service areas
Local platforms provide access to individual elements of the crane for maintenance and repair. Such sites are recommended as an alternative to mobile access (see 5.2). These sites must be accessible by mobile means or fixed means of access mounted on a crane.
If access to the site is carried out from a crane, then the passage to the site must be provided with the necessary ladders and fences (Figure 2). The site must be fenced on all sides. If an equivalent level of safety is provided by the crane elements, railings may not be installed.
6 Overall height
6.1 The height to the ceiling of a building, to the lower chord of trusses or to objects attached to them, as well as to the lowest point of another crane operating a tier above, is defined as the distance from the highest point of the crane to their lowest point.
The specified distance must be at least 400 mm. In this case, it is necessary to take into account the possible deformation of the ceiling (for example, under the influence of snow load). In special cases (for example, installation of cranes in existing buildings), it is allowed to reduce the overall height to 100 mm with a safety justification.
6.2 The overall height of the passage to the control cabin must be at least 2.0 m.
6.3 The overall height of passages and platforms for servicing the crane must be at least 1.8 m. In some areas, the height can be reduced to 1.4 m for no more than 1 m. Such places must be provided with warning signs and / or appropriate warning coloring.
6.4 Emergency exit
6.4.1 If access to the control cabin is not possible in any position of the crane, an alternate (emergency) way to exit the cabin should be provided in case of a crane malfunction or urgent evacuation is required.
6.4.2 The devices and fixtures listed in Table 2 provide an adequate level of safety, provided that at least 25% of the floor area under the tap is free from equipment and products, and the products do not pose a danger (not hot, not toxic, etc. ).
Table 2 - Recommended emergency exit devices
Height of the cab or adjoining platform to the ground or floor, m | Device |
Rope ladder, rope with knots or safety lock, rope descender |
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Telescopic or folding ladder, rope descender |
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from 1 to 15 and above | Inertial reels and belts, rope descender |
7 Protection and barriers
7.1 Protection against electric shock must comply with the requirements.
7.2 Guarding moving parts
Cranes moving on rails must be equipped with devices for cleaning the rails from foreign objects. The gap between the bottom of the device and the rail should be no more than 10 mm.
Moving parts of crane mechanisms (protruding ends of shafts and axles, belt, chain and gear drives, couplings, pulleys, wheels, etc.) located in the passage area must be protected.
Bibliography
ISO 4306-1:2007 Cranes - Vocabulary. Part 1: General terms (ISO 4306-1 Cranes - Vocabulary - Part 1: General). |
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ISO 11660-1:2008 Hoisting cranes. Means of access, fencing and protection. Part 1: General provisions (ISO 11660-1:2008 Cranes - Access, guards and restraints - Part 1: General). |
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ISO 14122-1:2001 Machine safety. Permanent means of access to machines. ISO 14122-1:2001 Safety of machinery — Permanent means of access to machinery — Part 1: Choice of fixed means of access between two levels |
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ISO 14122-1:2001/Amd. 1:2010 Machine safety. Permanent means of access to machines. Part 1. Selection of fixed means of access between two levels. Amendment 1 |
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ISO 14122-2:2001 Machine safety. Permanent means of access to machines. ISO 14122-2:2001 Safety of machinery — Permanent means of access to machinery — Part 2: Working platforms and walkways |
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ISO 14122-2:2001/Amd. 1:2010 Machine safety. Permanent means of access to machines. Part 2. Working platforms and bridges. Amendment 1 |
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ISO 14122-3:2001 Machine safety. Permanent means of access to machines. ISO 14122-3:2001, Safety of machinery — Permanent means of access to machinery — Part 3: Stairs, stepladders and guard-rails |
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ISO 14122-3:2001/Amd. 1:2010 Machine safety. Permanent means of access to machines. Part 3. Ladders, ladders and railings. Amendment 1 |
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ISO 14122-4:2004 Machine safety. Permanent means of access to machines. ISO 14122-4:2004 Safety of machinery - Permanent means of access to machinery - Part 4: Fixed ladders |
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ISO 14122-4:2004/Amd. 1:2010 Machine safety. Permanent means of access to machines. Part 4. Stationary stairs. Amendment 1 |
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IEC 60204-32(2008), Electrical equipment for industrial machines. Safety. IEC 60204-32(2008) Safety of machinery - Electrical equipment of machines - Part 32: Requirements for hoisting machines. |
UDC 621.873:531.2:006.354 | ISS 53.020.20 |
Key words: cranes, overhead cranes, gantry cranes, means of access, fencing, protection |
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Electronic text of the document
prepared by Kodeks JSC and verified against:
official publication
M.: Standartinform, 2014
