Stamping, which is performed using a metal press, is one of the most common technological operations for processing this material. The essence of this procedure is to give a workpiece made of metal the required shape, for which plastic deformation is used, squeezing out a certain relief, patterns or punching holes. Presses for metal processing, depending on the list of tasks for which they are intended, differ from each other both in their technical parameters and design.

Types of stamping technological operations and equipment

Stamping as a method of processing metal blanks can be:

• hot;
• cold.

The first implies that the metal is processed in a heated state. The great advantage of hot stamping is that when it is performed, the characteristics of the workpiece being processed are improved (in particular, the metal structure becomes denser and more uniform). Meanwhile, a layer of scale is not created on the surface of metal workpieces processed using technology, while the dimensions of the finished products are more accurate, and their surface is smoother.

Depending on the type of workpiece being stamped, such a technological operation can be sheet or volumetric. Stamping of the first type is used for processing sheet metal blanks; this technology is used to produce:

1. dishes;
2. jewelry;
3. weapon;
4. medical equipment and instruments;
5. parts of watches, household, climate control and electrical equipment;
6. parts for completing automotive equipment;
7. parts of machine tools and other engineering products.

Finished metal products obtained using technology do not require further refinement. The formation of their geometric parameters when performing volumetric stamping occurs in special forms in which hot or cold metal is subjected to extrusion.

The press machine is usually used for:

• production of metal blanks by forging;
• pressing and pressing out of shafts, bearings and gears;
• performing sheet and volume stamping.

According to the principle of operation, pressing machines can be of the mechanical or hydraulic type and perform metal processing using static or impact methods.

Mechanical pressing equipment can be designed according to its design:

• eccentric;
• crank.

Crank machines are used for both cold and hot. This stamping equipment is also used to perform such technological operations as drawing, cutting and cutting. The hydraulic press is used for stamping and forging technological operations with bulk metal blanks.

According to their functionality, pressing machines are divided into the following types:

• universal;
• special;
• specialized.

A universal pressing machine has the widest functionality; such equipment can be used to perform almost any forging operation. Specialized dies or presses are used to implement one technological process. Special presses that are used for stamping products of one type have minimal functionality, while their operation is based on one technology.

Design and principle of operation of pressing equipment

The design of any stamping equipment consists of the following elements:

1. drive motor;
2. motion transmission mechanism;
3. actuator.

Depending on how the drive motor of the press is connected to its actuator, machines with a connection are distinguished:

1. mechanical;
2. non-mechanical, carried out by liquid, gas or steam.

The actuating mechanism with which equipment for stamping is equipped can be traverses, a slider, rolls, rollers and women.

Crank type presses

The main structural element of these presses is the crank mechanism, which converts the rotational motion it receives from the drive into the reciprocating motion of the slider. The actuator, which is equipped with a stamping press of this type, is connected directly to the slider, capable of developing a force of up to 100 tons. The movement of the slider in such presses occurs at the same frequency.

Crank-type presses can be simple, double or triple acting equipment. Using such machines, you can perform the following technological operations:

• stamping using open and closed type dies;
• sheet metal cutting;
• firmware;
• formation of the finished product by extrusion;
• combined processing.

In cases where more powerful equipment is required to form a finished product from a metal blank, hydraulic type machines are used.

Hydraulic presses

Using a hydraulic press, you can press both larger and thicker-walled metal parts. Such equipment for sheet metal stamping, die stamping, forging, bending and other technological operations, depending on the specific model, can develop forces from 150 to 2000 tons or even more.

The main structural elements that any one is equipped with are two cylinders of different diameters, which are filled with working fluid and communicate with each other. Each of these hydraulic cylinders has a piston that creates pressure of the working fluid or moves under its influence. It is the movement of pistons in hydraulic cylinders that ensures the movement of the actuator of the equipment. The amount of force that such a stamping press can create is determined by the difference in the diameters of its hydraulic cylinders.

Radial forging presses

A radial forging machine is a forming press on which preheated metal blanks are converted into finished products of a cylindrical configuration. The design of presses of this type is:

• an induction furnace in which the workpiece is preheated;
• conveyor for feeding the workpiece into the processing zone;
• gripping mechanisms, with the help of which the metal part being processed, constantly rotating, passes through the forging zone;
• a worm gear connected to an electric motor and responsible for the operation of the gripping mechanisms;
• four shafts with eccentric axle boxes that transmit movement to a connecting rod with a striker, between which a slider is fixed (the shafts themselves receive rotation from a drive electric motor through a V-belt drive);
• copying drums, responsible for the synchronous approach of the strikers and the subsequent movement of the workpiece;
• a spring clutch that provides braking of the part while it is being processed by the strikers.

Radial forging machine is used to produce square or round forgings close to the profile of finished products

Hydraulic Punch Press is an indispensable assistant for punching holes in metal (sheet, angle, channel, etc.). The punching press is a C-shaped frame with a hydraulic cylinder of direct vertical stroke, due to which punching is performed with maximum quality and tool life. PM series machines are designed for punching holes in metal with a thickness of 2mm to 35mm. Punching presses can be equipped with systems for automatic feeding and positioning of the workpiece (sheet, angle, channel).

PM punching press require manual positioning of the workpiece by the operator. To facilitate the positioning of sheets and other assortments, the press includes a small supporting table with a ruler and stops. For more accurate positioning of the workpiece, punching presses are equipped with an inexpensive system for laser indication of the punching center, and for productive periodic punching of holes - an extended table with adjustable stops, or a CNC-controlled feed table.

Distinctive feature of hydraulic punching presses PM series are:

• The highest quality hole punching (smooth hole edges and minimal deformation), while ensuring maximum tool life (punch and die).
• Hydraulic cylinder with fast return stroke - significantly reduces waiting time when moving the punch up.
• Ease of tool setup and operation. All Sunrise hole punching presses have a low pressure mode, that is, when adjusting (replacing) the punch / matrix, to check the gaps, the hydraulic cylinder with the installed punch is lowered with the minimum possible pressure and speed, thereby, if the tool is installed incorrectly, it will not break .
• Possibility of using special tools to perform operations: cutting corners, strips, rods, cutting grooves.

Hydraulic punching presses from the Sunrise company (Sunrise) -This is truly impeccable quality equipment. Sunrise is one of the world's three largest manufacturers of shear presses, punching presses and automation systems, with an annual production of about 2,000 machines. You can read more about Sunrise and its advantages over other competing companies in the “ABOUT THE COMPANY” section.

Explanation of the abbreviation in the name of PM hydraulic punching presses:

• P.M.= "PunchMachine", that is, a machine for punching holes.
• 55 (digit) - force of the punching hydraulic cylinder (tons).
• T(LT/XT)- depth of the bed mouth (distance from the punching punch to the bed). "T" = 310mm, "LT" = 510mm, "XT" = 760mm.
• Example: Model PM-80LT means a punching press with a force of 80 tons and a throat depth of 510mm.

Hydraulic punching press PM-35T (LT/XT)- the most popular for comfortable work with sheets up to 10-12mm, as well as a wide range of assortments (angle, channel, etc.). With a compact design and high-speed hydraulic cylinder, the PM-35 presses are ideal for versatile work in any production area.

Hydraulic punching press PM-55T (LT/XT)- excellent combination of medium power, high speed and compact design. In addition to punching holes, punching presses allow you to bend sheets/angles, cut grooves and cut assortments using additional equipment.

Hydraulic punching press PM-80T (LT/XT)- productive machines of medium power, with a compact design. They work comfortably with workpiece thicknesses up to 20mm. They are often equipped with a CNC feeding table for automatically moving sheet blanks according to a program. Suitable for a wide range of production tasks.

Hydraulic punching press PM-120LT/XT- powerful machines with a deep bed opening. They work comfortably with workpiece thicknesses up to 20 - 25mm. To move heavy sheets, they are often equipped with a CNC-controlled feeding table. Popular in the production of metal structures.

5.00 /5 (100.00%) 4 voted

Punching holes. Punching press.

Punch and matrix.

When punching holes, the role of the upper movable knife is played by the punch (stamp), and the lower, stationary knife is played by the matrix (stamp). The hole formation process and the working parts of the punching device are shown in Fig. 1.

The end of the punch entering the matrix and the hole in the matrix have the shape of a truncated cone with its apex facing upward. The cutting edges of the punch and matrix have angles of 99°, the bevel angle is 1°. With this shape of the punch, friction is reduced as it passes through the metal being pierced. When the die hole is conical, the extruded metal easily falls out of the die hole.

Fig.1. Metal punching:

1 – punch; 2 – matrix.

Punches and dies are made from tool carbon steel and are made interchangeable, that is, they are manufactured according to certain standards.

To punch a hole, the sheet is laid so that the core A . delivered on the sheet when basting, it fell exactly under the taper of the punch. Then the punch is turned on, which, by pressing the sheet between the cutting edge in the matrix and the cutting edge b punch, chips metal.

Lever and screw bearer.

The holes are pressed manually using lever presses and presses. Two types of bears are used: lever and screw. The screw bearer (Fig. 2, a) has the appearance of a steel bracket; it can be forged or cast. There is a fixed matrix at the lower end of the bracket, and a screw with a punch passes through its upper end. The sheet is placed between the matrix and the punch so that the tip of the punch fits into the recess marked by the core. Then turn the screw 1 handle 2 . The punch cuts into the metal and pierces a hole. The work requires a lot of force, so bears are used to pierce holes of small diameters and in sheets of small thickness.

Fig.2. Medvedka:

a – screw; 1 – screw; 2 – handle; 3 – bracket (housing); 4 – sheet; 5 – punch; 6 – matrix;

b – lever; 1 – screw; 2 – lever; 3 – bracket (housing).

The lever bearer is more advanced (Fig. 2, b). Medvedka has a screw 1 with left and right cuts. The lower nut of the screw is connected by a lever to the punch. As the screw rotates, the lever moves and the punch cuts into the metal, creating a hole.

Medvedkas are low-productive and are not used for mass production. Typically, hammers are used during repair work to punch a small number of holes.

Manual punch press. Manual lever press.

Manual punching and lever presses also operate on the same principle as the bearer. When punching holes in thin sheets, manual punching and lever presses can be compared to powered presses in productivity and efficiency.

Punch presses. Designs and principle of operation.

Driven punching presses for punching holes, used in repair shops, are manufactured welded, with welded cast iron or steel cast frames. Most often they are made double, because this way they are more compact and take up less space. A table made of steel sheets is installed in front of the punching presses; they serve as supports for the sheets being processed. Punching tables consist of a trestle with rollers. The rollers have slots for the vertical shelf of the corner. Punching presses are most often made with a belt drive from an electric motor and less often hydraulically.

In addition to punching presses, repair shops use automatic punching presses to punch holes.

To punch holes, each sheet is pre-marked or marked. On automatic punching presses, the sheet is divided into the required number of equal parts automatically. In this case, the straightened sheet is attached to a table that moves along the machine. The machine table can be stopped at any place by an automatic switch, which is driven by an electric drive.

To obtain the required number of divisions, only four corner points (on which the cores are placed) and center lines are applied to the sheet. The sheet is first installed with one corner core against the pointer associated with the indexing device, and is moved by the machine support to another corner point on the same center line, automatically determining the distance between them. Then the support returns to its original position, the divider is set to a certain number of divisions according to the number of holes required, and the machine pierces the holes.

The remaining holes on the sheet are also pierced.

Large holes (for manholes, pipes, etc.) in the middle of the sheet are formed by gouging. To reduce subsequent processing of the edge of the hole, the punch is given a rectangular cross-section with rounded corners.

The edges of the hole processed with such a punch have the correct outline without protrusions, do not require trimming with a chisel, but are only filed with a file.

Fig.3. Device for cutting holes for flame tubes.

Recently, large holes have been created by gas cutting. Pipe holes, the walls of which must have a smooth surface, are drilled using a special device (Fig. 3.).

A punching press is equipment for cold forming of metals.

It is used mainly for punching various holes in sheet metal.

The principle of operation is based on the conversion of external energy into potential energy through transmission to the actuator, while the metal is separated by pressure using a movable tool that shifts the material relative to a stationary tool. Such equipment is manual, which in turn is divided into lever-screw and hydraulic.

On hand presses, holes of no more than 20 mm are punched. in metal up to 20 mm thick. The main convenience is that due to their small size they are easy to move. There is drive (mechanical) equipment based on a crank (eccentric) shaft.

Mechanical punching presses come in vertical and horizontal types. They are used to speed up the process of punching holes in structural parts that are manufactured in mass and serial production. They can have a large number of holes and punches in the matrix.

There are divisions of hole-punching presses by design into single-stamp, two-stamp, four-stamp and multi-stamp. Not all mechanical presses are created equal in performance.

In a sheet bending machine equipped with a multi-stamp tool, the punches work in steps and due to this, it is possible to obtain greater productivity than in others.

For mass production, hole punching is used on vertical copy presses with a duplicator table. The latter are designed for punching holes of any shape and arbitrary location.

Design

The design of the punching press consists of a vertical frame where on the lower working surface there is a matrix for the punch and the punch itself is fixed above the matrix in a slider that receives movement from an eccentric and makes reciprocating movements in special guides.

There are hole-punching presses with program control, which are designed with a table moving in perpendicular directions and a turret head, the mechanism of which is equipped with a drive that programmably sets the tool to the punching position.

A hydraulic punching press allows bending of sheets, strips and rods of thick-walled materials. The range of work can be expanded by purchasing additional equipment. This will allow you to cut out ventilation louvers, punch holes of various diameters, process pipe edges and form metal blanks with high precision.

Hydraulic punching presses help

• significantly increase production volume,
• perform fairly complex work with metal,
• do not stop the production process when moving from the production of one workpiece to another.

Sahinler hydraulic punching presses: description

1. In models HPM 65, 85, 115 and 175, the number indicates the force that is applied in the production of one part. The thickness of the material being punched depends on the value of this indicator.
2. HRM 65, 85 and 115 DP have two independent work tables.
3. HRM 65, 85, 115, 175 CNC are optimally suited for punching holes in precisely marked locations on sheet metal in X and Y coordinates.