Not a single process of stamping parts, pressing and labeling of various products occurs without the use of special equipment called a punch. What is it and how is it used, we will analyze in this article.
Definition
Pressing devices consist of a container in which a punch, die, needles and other components are located. What is a punch? It plays an important role in the stamping or labeling process and is one of the main elements of the pressing device. The task of the punch is to pressure the metal part to highlight certain characters or holes on it. Also, using this equipment, you can squeeze out the necessary part, apply standard or mirror markings and stamp the required number of elements.
Types of punches
According to the type of construction and the method of influencing the part, the following types are used:
- cutting devices;
- piercing punches;
- perforated elements;
- punch presses.
If you need to create a large volume of parts, it is possible to place the punch in a specially made clip.
Workmate
An equally important detail when stamping products is the matrix. It represents a box in which the punch should enter. The matrix is directly involved in the process of forming a mold on the surface of the workpiece. In direct stamping press equipment, the die is a chamber into which the press material is loaded. The lower part of the box draws an image on the part, and a punch is sent from above to the contents. Depending on the complexity of the manufactured part, there are solid and composite matrices.
How does the press work?
In the process, the punch (what it is, we examined at the beginning of the article) acts on a metal part by pressure on a special washer, which, in turn, passes through the matrix. Thus, the necessary form is procured. During operation, parts of the pressing equipment are subjected to tremendous pressure, reaching up to 500 kg per 1 square. mm And also constantly heated to a level above 200 degrees. In this regard, the stamping parts and the press wear out. And due to the additional impact of the processed products, punches and dies lose their hardness over time. Therefore, their resistance depends on the material from which they are made.
Making punches
In the production of punches, high-precision machines with software control are used. Originally used milling machines, which mechanically perform and process the workpiece. Then they are ground and then, with the help of metalwork equipment, the working contour of the stamp is applied to the surface. After making the punch, it is placed in a special hardening furnace.
The punches made can be cylindrical and shaped, the production of which is subjected to a longer and more complex process. Punches containing letters or numbers are also produced. This is a steel piece with a square section, having a sawed-off tip, on which the necessary sign is engraved. A punch of this form is branded with various numbers, metal parts, machine elements and other products.
The matrix, in turn, is made after the punch using its print. The container should be slightly larger in width and size. Therefore, the necessary clearance between the parts is adjusted by independent processing.
Parts of the press equipment wear out quickly, so they should be changed periodically. The life of the punches is influenced by the methods of manufacturing the dies and the scope of production. The average duration of the press components is about 6 years.
What are punches made of?
An important requirement for stamps and punches is a competent choice of material from which they will be made. The worse the steel, the lower the productivity of the press equipment. Volumetric punches having complex shapes are made of high-chromium and high-carbon steel alloys. The most common material is steel marked X12F1. It has high wear resistance, excellent hardenability, and does not undergo significant deformation during operation. U8A - U11A carbon tool steels are used for the production of simple types of dies.
Parts made of refractory metals, during operation, retain their hardness and do not lose their shape. In order to increase the durability of the dies, materials from hard and high-speed alloys were introduced into production. The cutting edge is applied to the die or die body. The best results in the production of press parts showed alloys such as stalinite and stellite. They provide hardness to the elements without the need for hardening.
Punching sheet metal
The work 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 according to a predetermined contour. In the process of cutting, internal holes are formed. The process of using dies, punches during punching resembles 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. By the end of the work, reaching maximum pressure, the metal fibers are torn and a corresponding cut on the product is performed.
In the article, we examined what equipment such as a punch is made of, what it is and where it is used. With their help, coins, medals, badges, stamps, textured drawings, medicines and many other products are minted.