What Is Stamping Die Structure? What Are The Classifications?

In the cold stamping process, stamping die processes materials (metal or non-metal) into parts (or semi-finished products). Stamping is a kind of pressure processing method which uses the die installed on the press to exert pressure on the material at room temperature to produce separation or plastic deformation, so as to obtain the required parts. The die installed on the press is equipped with die accessories, such as punching needle, and then directly contacts with the material (metal or non-metal), which makes the material separate or plastic deformation, so as to obtain the required parts. Stamping die is an essential process equipment for stamping production, and it is a technology intensive product. The quality, production efficiency and production cost of stamping parts are directly related to die design and precision quality of die parts. The following Xianji network editor to introduce the relevant knowledge of stamping die, including: stamping die structure, classification, material types and characteristics, design and production skills.

Stamping die structure

The structure of metal stamping die can be divided into upper die and lower die. The upper die is composed of die handle (punch handle), guide sleeve, punch, base plate, fixing plate, screw, pin, upper die seat (upper bracket) and stripper plate. The lower die is generally composed of lower die base, guide plate (side guide plate), die, baffle plate, bearing plate, guide pillar, screw and pin.

1. Above is a common blanking die, the product is a rectangle, with three small round holes punched in the middle;

2. Blanking and punching compound punch is a cuboid, which is used to unload the shape of the product from the material. The four sides of the blanking and punching compound punch are also knife edge, which is equivalent to the punch, so the four sides can not be chamfered. There are three small round holes in the middle of the blanking and punching compound punch, which belong to the knife edge, that is, to punch out the three round holes in the middle of the product.

3. There is a square hole in the middle of the concave template, which belongs to the edge of the knife. The blanking and punching compound punch punches the product shape for the punch. The corresponding inner stripping on the blanking and punching compound punch is also called inner stripping plate, or inner discharging plate. What is marked in the figure is "discharging block". In fact, it means the same thing. The function of discharging block is to push the product out of the concave template. The discharging block has another function The first function is to press the material, press the material, and then punch the three small round holes in the middle.

4. The "top punch" marked in the figure is actually a punch, which is used to punch out the three small round holes on the intermediate product with the three circular knife edges on the blanking and punching compound punch.

5. The function of the "fixed key" on the lower base plate of the lower die is to fix the blanking and punching compound punch, so as to prevent it from jumping out of the die with the upward movement of the die, resulting in accidents.

6. The "discharge plate" marked on the lower die is commonly known as external stripping, which is used to strip the punched waste from the blanking and punching compound punch, so as to avoid the waste stuck on the blanking and punching compound punch.

Classification of stamping die

There are many forms of stamping dies, which are classified according to the nature of work, die structure and die material.

1、 Classification according to process properties

1. Blanking die

A mold that separates materials along a closed or open contour. Such as blanking die, punching die, cutting die, cutting die, trimming die, cutting die, etc.

2. Bending die

The die can make the blank or other blank produce bending deformation along the straight line (bending curve), so as to obtain the workpiece with a certain angle and shape.

3. Drawing die

It is a kind of mould to make the blank of sheet metal into open hollow parts or to further change the shape and size of the hollow parts.

4. Forming die

It is a kind of mould that directly copies the blank or semi-finished product according to the shape of punch and die, but the material itself only produces local plastic deformation. Such as bulging die, necking die, expanding die, relief forming die, flanging die, shaping die, etc.

5. Riveting die

It is to use the external force to make the participating parts connect or lap together in a certain order and way, so as to form a whole.

2、 Classification according to the degree of process combination

1. Single process Die

In a press stroke, only complete a stamping process of the mold.

2. Compound die

Only one station, in a press stroke, in the same station at the same time to complete two or more stamping process of the mold.

3. Progressive die (also called continuous die)

In the blank feeding direction, there are two or more stations, in a press stroke, in different stations to complete two or more stamping processes.

4. Transitive module

Combining the characteristics of single process die and progressive die, using manipulator transfer system to realize the rapid transfer of products in the die can greatly improve the production efficiency of products, reduce the production cost of products, save the material cost, and the quality is stable and reliable.

3、 Classification according to the processing method of products

According to the different processing methods, the dies can be divided into five categories: punching and shearing dies, bending dies, drawing dies, forming dies and compression dies.

1. Punching and shearing die:

The common forms include cutting die, blanking die, punching die, trimming die, trimming die, trimming die, broaching die and punching die.

2. Bending die:

According to the shape, precision and production capacity of the parts, there are many different forms of dies, such as ordinary bending die, cam bending die, crimping die, arc bending die, bending and sewing die and twisting die.

3. Drawing mould:

The drawing mould is to make the flat rough embryo into a bottomless seamless container.

4. Forming die:

There are many ways to change the shape of the punch, such as forming of the punch, forming of the flange, forming of the punch, forming of the flange.

5. Compression mold:

It is the use of strong pressure to make the metal embryo flow deformation and become the required shape. Its types include extrusion die, embossing die, embossing die and end pressing die.

Types and characteristics of stamping die materials

1. Carbon tool steel

T8A, T10A and other carbon tool steels are widely used in the die, which have the advantages of good processability and low price. But the hardenability and red hardness are poor, the heat treatment deformation is large, and the bearing capacity is low.

2. Low alloy tool steel

Low alloy tool steel is based on carbon tool steel with appropriate amount of alloy elements. Compared with carbon tool steel, the quenching deformation and cracking tendency are reduced, the hardenability and wear resistance of the steel are improved. The low alloy steels used for manufacturing dies are CrWMn, 9mn2v, 7CrSiMnMoV (code CH-1), 6crnisimnmov (code GD), etc.

3. High carbon and high chromium tool steel

The commonly used high carbon and high chromium tool steels are Cr12, Cr12MoV and Cr12Mo1V1 (code name D2). They have good hardenability, hardenability and wear resistance. The heat treatment deformation is very small. They are high wear resistance and micro deformation die steels, and the bearing capacity is only second to high speed steel. However, the carbide segregation is serious, so it is necessary to carry out repeated upsetting and drawing (axial upsetting and radial drawing) to reduce the inhomogeneity of carbide and improve the service performance.

4. High carbon medium chromium tool steel

The high carbon medium chromium tool steels used for dies include Cr4W2MoV, cr6wv, Cr5MoV, etc. they have low chromium content, less eutectic carbide, uniform carbide distribution, small heat treatment deformation, good hardenability and dimensional stability. Compared with the high carbon and high chromium steel with serious carbide segregation, its properties are improved.

5. High speed steel

High speed steel has the highest hardness, wear resistance and compressive strength in die steel, and high bearing capacity. W18Cr4V (code 8-4-1), W6Mo5Cr4V2 (code 6-5-4-2, American brand m2) and 6w6mo5cr4v (code 6w6 or low-carbon m2) are commonly used in dies to improve toughness. High speed steel also needs to be forged to improve its carbide distribution.

6. Matrix steel

In order to improve the properties of high speed steel, a small amount of other elements are added to the basic composition of high speed steel, and the carbon content is increased or decreased appropriately. This kind of steel is called matrix steel. They not only have the characteristics of high speed steel, have certain wear resistance and hardness, but also have better fatigue strength and toughness than high speed steel. They are high strength and toughness cold working die steel, but the material cost is lower than high speed steel. The matrix steels commonly used in dies are 6cr4w3mo2vnb (code 65Nb), 7Cr7Mo2V2Si (code LD), 5cr4mo3simnval (code 012AL), etc.

7. Cemented carbide and steel bonded cemented carbide

The hardness and wear resistance of cemented carbide are higher than those of other die steels, but the bending strength and toughness are poor. Tungsten and cobalt are used as the hard alloy for mould. The hard alloy with low cobalt content can be used for mould with low impact and high wear resistance. For high impact dies, cemented carbide with high cobalt content can be selected.