Precision stamping dies can be classified into three categories as follows: Engineering die: also known as "single process Die", which refers to the die that can only complete one stamping process in one stroke of stamping. After the completion of this project, the product needs to be taken out of the mold manually or by manipulator, and then put into the mold at the next station to continue production. The whole product is not completed until the next process of the mold is completed. Mold maintenance is simple, but production is time-consuming and laborious, requires more labor and time costs, and the product scrap rate is high.
Composite die: common composite die structures include composite blanking, composite drawing, etc. this die structure is slightly different from other engineering die structures. The punch (also known as male die or punch) is designed in the lower die. The other templates are the lower splint (fixed punch), the lower stop baffle and the lower stripper plate (outer stripper). The upper die is composed of the mother die (or knife edge), the inner stripper plate and the upper backing plate. The inner stripper is hung on the upper backing plate with an equal height sleeve, and then pressed with a driving rod or spring.
Continuous die: also known as "progressive die", it refers to a die that completes two or more stamping processes at different stations at the same time in one stroke of stamping. This kind of die is difficult to maintain and needs experienced fitter to operate. However, it has high production efficiency, can save labor and time costs, and the scrap rate of precision metal stamping parts is low.
In order to prolong the service life of the workpiece and avoid corrosion and rust during the processing of automobile stamping parts, the corresponding anti-corrosion treatment is generally done. The common anti-corrosion treatment methods are as follows:
For asphalt paint coating, preheating the workpiece before painting can improve the adhesion of asphalt paint and accelerate drying.
Cement mortar lining with special coating can improve the corrosion resistance of workpiece lining.
Epoxy coal tar pitch coating is a two-component coating with high adhesion and very smooth surface.
Epoxy ceramic lining has certain limitations in use because of its difficult manufacturing process and high cost. It has high adhesion and finish. It is an excellent anti-corrosion coating for stamping parts.
Aluminate cement coating or sulfate cement coating, these two special cement coatings are applicable to the internal corrosion protection of high-precision stamping parts to improve the ability to resist erosion.
Polyurethane coating is a new green special coating developed to meet the needs of environmental protection. It has good wear and corrosion resistance.