Work on stamping and pressing of various workpieces requires the use of special punches. This product is used for marking device components during metal processing or in the stamping process. In order to make high-quality stamping or marking of a device assembly, direct pressure must be applied to it. It is for this purpose that the punch was developed, which can be of very different designs.
Experts identify the following types of such devices:
- cutting;
- punching;
- piercing;
- perforated
How dies and punches work
During pressing, a durable tamping punch exerts strong pressure on a special press washer, which in turn transfers pressure to the workpiece. As a result, the desired workpiece is squeezed out through the matrix. The punch is capable of operating under enormous thermal and power loads, so it is made from wear-resistant metal. The device is very durable and is not damaged by temperature changes.
In other words, a die is considered a device that, using pressure, can produce a workpiece of the required shape and size. When stamping various parts, it is the most important tool. When polyurethane is used together with it, a high-quality matrix is made from it, which will be the response unit of the stamp.
When assembling any type of stamp, the design of this device always completely coincides with the cutting edge of the matrix. In other words, such a product is a closing unit that is capable of creating the upper part of the workpiece. A set of punches is a small press that can efficiently mark or stamp various components. Using this device, it is possible to produce blanks of any size or apply high-quality markings, which can be mirrored or regular.
Punch sets are used in metalworking plants that press iron blanks or produce sheet metal parts. In the construction industry, using this device, you can make aerated concrete blocks that have various voids.
Making punches
In the production of punches, high-precision machines with program control are used. Initially, milling machines are used, which mechanically produce and process workpieces. Then they are polished and then, using metalworking equipment, the working contour of the stamp is applied to the surface. After the punch is made, it is placed in a special furnace for hardening.
The punches produced can be cylindrical or shaped, the production of which is subject to a longer and more complex process. Punches containing letters or numbers are also produced. This is a steel piece with a square cross-section, having a sawn tip, on which the required sign is engraved. A punch of this shape is used to brand various numbers, metal parts, machine elements and other products.
The main purpose of the matrix
In order to make a workpiece of the required shape, a matrix is used, which can be made from:
- polyurethane;
- rubber;
- various metals.
To make an iron part, the matrix must be made of specialized strong steel, which has high wear resistance. Such a structure should be equipped with polished walls and not have a lid.
Experts distinguish the following types of matrices:
- simple;
- complex;
- universal.
The most complex design solutions are used quite rarely, so they are produced to individual order. An example of simple matrices is molds for the production of various blocks and small bricks.
Materials for the manufacture of punches and dies
The main task of a set of punches is to force the part through the matrix. This work is done under enormous pressure. When using hot pressing, the workpieces are exposed to high temperatures. Because of this, different types of materials are used to produce punches and dies. Devices for cold pressing are made from specialized high-strength steel, which has a high degree of hardening.
The materials for the manufacture of these parts meet the following characteristics:
- high degree of wear resistance;
- great strength;
- corrosion resistance.
Alloy steel is not suitable for high temperature applications. Metal can become brittle under the influence of temperature differences. Any punch has the highest degree of hardness over its entire height. In the hot method of manufacturing dies for steel stamping, the upper part of the product is made of specialized metals that are not subject to deformation at high temperatures and have a high degree of wear resistance. This technology can provide the greatest durability of the device. Sometimes modern types of various polymers are used. For example, it could be polyurethane, which has good elasticity and great strength.
Types of punches.
Depending on the functions they perform, there are four types of punches: punching, cutting, piercing and expanded punches. These parts may be subject to thermal or power loads. Based on the scope of application, wear-resistant steels that have high strength when exposed to high temperatures or increased hardenability are used for the manufacture of punches.
In the manufacture of punches, Metalloobrabotka LLC uses various grades of tool carbon steel with a degree of hardening in the range of 54-65 HRC. Alloy steel is not entirely suitable for such purposes, as it becomes brittle when exposed to high temperatures.
The punch production process consists of several sequential steps. So, the action begins with the manufacture of a workpiece that can be machined. Next, rough and fine grinding, hardening and sharpening of the profile are carried out.
Make punches
cylindrical shape is extremely simple. Thus, the blank for such products can be metalworked, polished and grinded. The production of shaped punches is much more complex. Initially, with the help of metal-cutting equipment, the contour of the punch is processed, on the basis of which an impression is made. Based on the finished impression, the punch is processed, further hardened and final processed. Basically, punches are hardened at a temperature of about 780 degrees for eight minutes.
The production of punches with complex contours is possible using several types of equipment. Thus, it is advisable to process punches with a flange and a constant cross-section using planing or milling machines. Punches with shoulders can be processed on shaping and planing machines. Processing is carried out based on the impression or along a pre-marked contour.
If the necessary conditions are not met during heat treatment, deformation of the workpiece surface may occur. Metalloobrabotka LLC is engaged in the manufacture of punches
high quality, observing all technological requirements during production.
The production of punches
is carried out using innovative technologies of profile grinding, heat treatment and marking. Thanks to a well-established production process, it is possible to produce high-quality punches in a short time.
Depending on the purpose, a graphic image (numbers or letters) can be applied to the punch either directly or in a mirror image.
In most cases, dies are also used in parallel with punches. The production of dies, dies, and punches is possible using high-precision machines equipped with program control. The manufacturing process for these parts has many similarities. Thus, initially the matrix or punch blank can be processed on vertical milling machines. After this, the surface of the workpiece is polished using special equipment. Next, the working contour is marked using metalworking and milling machines, and hardening in a furnace. Accordingly, the production of punches and dies can be carried out on the same equipment, with the only difference being the size of the parts.
Main characteristics of the product
Absolutely any type of stamps has a certain warranty period. The main components of this device are the matrix and the punch, which wear out quite quickly. These units must be changed regularly because they can last about 5 years without replacement. The equipment of vibration presses and stamping devices has a different design. This is done so that it is possible to carry out various technical operations.
For this reason, extensive grinding is performed when producing cylindrical dies. Craftsmen do rough processing of the device, and then clean grinding. The device is sharpened and polished at the last stage of its manufacture.
To make shaped punches, a technological impression is used. The device is hardened in a hot oven for 10 minutes. Next, the final sanding begins. To obtain a product of complex shape, a large amount of specialized equipment is used. It is almost impossible to do without the use of milling and planing machines.
Similar equipment is needed for matrix production. When the molds for the press are made of very high quality, and the punch is equipped with an accurate cut line, the stamp will have a high degree of wear resistance and a long service life. Experts believe that making stamps with your own hands is very difficult. To do this, you need to have a lot of knowledge in the field of metal processing.
Punching of sheet parts
The operation of the press by punching is quite simple. In this case, one part of the material placed in the equipment is separated from the main one along a specific contour. The cutting process creates internal holes. The process of using stamps and punches for punching is reminiscent of cutting parts with scissors. In this case, the cutting components are the matrix and the punch, which have sharp edges.
The drawing of the punch clearly shows how the metal is pressed into the lower part of the matrix, followed by bending and deformation of the material. Towards the end of the work, reaching maximum pressure, the metal fibers break and a corresponding cut is made on the product.
In the article we looked at what equipment such as a punch is made of, what it is and where it is used. With their help, coins, medals, badges, seals, textured designs, medicines and many other products are minted.
