First, according to the finished product of the workpiece.
Stamping process can be roughly divided into separation process and forming process (bending, stretching and forming) according to the finished product of workpiece.
(1) The separation process is to make the stamping parts and blanks separate from each other along a certain contour line in the stamping process, and at the same time, the quality of the separation section of the stamping parts should meet certain requirements;
(2) The forming process is to make the stamping blank undergo plastic deformation without damage and transform it into the required finished product shape, and at the same time, it should meet the requirements of dimensional tolerance and other aspects.
Second, according to the temperature during stamping.
According to the temperature of hot stamping, there are two ways: cold stamping and hot stamping. It depends on the strength, plasticity, thickness, deformation degree and equipment capacity of the material, and also considers the original heat treatment state and final use conditions of the material.
(1) Cold stamping metal processing at room temperature is generally suitable for blanks with small thickness. Its advantages are no heating, no scaling, good surface quality, convenient operation and low cost. The disadvantage is that there is work hardening phenomenon, which makes the metal lose its further deformation ability in severe cases. In most cases, cold stamping needs to use stamping oil to improve the process, and at the same time, the blank thickness is required to be uniform, the fluctuation range is small, the surface is smooth, and there are no spots and scratches.
(2) Hot stamping is a stamping method that heats metal to a certain temperature range. Its advantages are eliminating internal stress, avoiding work hardening, increasing the plasticity of materials, reducing deformation resistance and reducing equipment power consumption.
Third, according to the mold structure:
Stamping die is a tool for separating or deforming metal plates, which consists of an upper die and a lower die. The handle of the upper die is fixed on the slider of the punch and moves up and down with the slider, and the lower die is fixed on the workbench of the punch. It is an essential die in stamping production. According to the die structure, the process can be basically divided into three types: simple stamping, continuous stamping and composite stamping.
(1) Simple stamping is a stamping process in which only one process is completed in one stroke of the punch. That is, a simple punching die for punching or punching. When the punch presses down, the punched parts (or wastes) enter the hole of the female die, and the strip-shaped material clamps the punch and moves up with the punch.
(2) Continuous stamping refers to the simultaneous completion of several stamping processes in different parts of the die in one stroke of the punch. Through circulation, each feed distance is controlled by a stop pin.
(3) Composite stamping is to complete several stamping processes in one stroke at the same part of the die. The biggest feature of compound stamping is that there is a convex-concave die in the die. When the slider moves down with the punch and die, the aluminum strip first falls into the punch and die. The blanking part is supported by the drawing punch in the lower die. When the slider continues to move downwards, the female die moves downwards for drawing. The compound die is suitable for stamping parts with large output and high precision.
Fourth, according to the basic working procedures.
According to the basic process, the main basic processes of stamping are divided into blanking, punching, bending and stretching.
(1) blanking and punching blanking and punching are the processes of separating blanks. The process of blanking and punching is exactly the same, but the purpose is different. When blanking, the separated part is the finished product, and the rest is the waste; Punching is to get holes. Punching is the finished product, and the separated part is the waste. Blanking and punching are collectively called blanking. Both the punch and the die of the blanking die have sharp cutting edges, and there is a gap between the punch and the die to ensure that the cut is neat and there are few burrs.
(2) Bending is to make the workpiece obtain various bending angles. The working part of the bending die for bending the workpiece should have a suitable fillet radius to avoid cracking when the workpiece is bent.
(3) Deep drawing is the process of making a flat blank into a cup-shaped or box-shaped part. The edges of the punch and die of the drawing die should be round to prevent the workpiece from being pulled apart. There should be a gap slightly larger than the thickness of the metal plate between the punch and the die to reduce friction. In order to prevent wrinkling, the edge of the blank needs to be pressed with a pressure plate.
5. Divide according to the material of stamping workpiece.
Commonly used plates are low titanium alloy, carbon steel, stainless steel, aluminum, copper and their alloys. They have high plasticity and low deformation resistance and are suitable for cold stamping.
(1) Cu-Al and its alloys are widely used as internal components of electrical equipment because of their good ductility and excellent conductivity.
(2) The stamping process of carbon steel and stainless steel is often used to manufacture equipment shells, structural parts, boxes, etc. However, due to its strong rigidity, stamping oil is usually used to improve the process.
(3) Titanium alloy stamping is mainly used in large-scale equipment, airplanes, ships, satellites and other scenes with high weight requirements. The processing technology is difficult and costly, so special stamping oil must be used to improve the process level.
The above is the distinguishing method of stamping process types. Reasonable arrangement of process, use of special stamping oil and selection of reliable raw materials can effectively improve product quality.