How to ensure the large parts and dimensional accuracy of automobile stamping parts?

2021-04-27 10:16:27

Stamping is a kind of production technology which makes sheet metal directly subject to deformation force and deform with the help of conventional or special stamping equipment, so as to obtain a certain shape, size and performance of product parts. Sheet metal, die and equipment are the three elements of stamping process. Stamping is a kind of metal cold deformation processing method. Therefore, it is called cold stamping or sheet metal stamping, referred to as stamping. It is one of the main methods of metal plastic processing (or pressure processing), and also belongs to material forming engineering technology. The die used for stamping parts is called stamping die, which is called stamping die for short. Stamping die is a special tool for batch processing materials (metal or non-metal) into required stamping parts. Stamping die is very important in stamping. Without qualified stamping die, it is difficult to carry out batch stamping production; without advanced stamping die, advanced stamping process cannot be realized. Stamping process and die, stamping equipment and stamping materials constitute the three elements of stamping process. Only when they are combined can stamping parts be obtained.

It depends on the size of the unloading force, and the material thickness is the main factor. With the increase of the elastic force of the elastic element used in the die (such as the use of rectangular spring), the unloading force of the elastic unloading plate is greatly enhanced. Metal stamping is a kind of forming processing method that applies external force to plate, strip, pipe and profile by press and die to produce plastic deformation or separation, so as to obtain the workpiece (Stamping) with the required shape and size.

When the manufacturing accuracy of the die is high, the dimension accuracy of the metal stamping parts can reach it10 level, and the inner hole size can reach it9 level.

The surface quality of metal stamping parts should not be higher than the surface quality of raw materials, otherwise it needs to increase the subsequent processing to achieve, which increases the production cost.

The dimensional accuracy of metal stamping parts refers to the difference between the actual size and the basic size of stamping parts. The smaller the difference, the higher the dimensional accuracy of metal stamping parts. The main factors causing dimensional error of metal stamping parts are: manufacturing accuracy of punch and die; clearance between punch and die; elastic recovery of material after stamping; accidental factors in the production process, such as inaccurate positioning and unstable material performance.

There are more than ten large parts of automobile stamping parts: the inner and outer panels of the cover, the top cover, the left and right of the fender, the left and right of the outer panels of the large side wall, the inner and outer panels of the trunk, the left and right of the inner and outer panels of the front and rear doors, and the front, middle and rear floors.

Automotive stamping parts are divided into many categories, and the steel plates used for different types of parts are also different.

Some sealing plates and supports with low performance requirements and uncomplicated shapes will use steel plates with general tensile properties;

Because of appearance requirements, large outer panels will use steel plates with special requirements;

Some parts with relatively complex shape, deep shape or rapid change need steel plates with good tensile properties;