In the process of automobile stamping, sometimes the die punch will suddenly fall off, so what causes the punch to fall off? In fact, the main reason for the analysis of punch dropout is that the punch is not strong. What is the reason why the punch is not fixed firmly? The main reasons are as follows:
1. For the fixed structure of the punch that is pressed into the interference, because the required amount of interference cannot be met during the manufacturing process, the method of “twisting and squeezing” is used to remedy it, so that the punch is easy to loosen.
2. If the punch is not fixed by steps or fasteners, punch thick, hard or viscous materials. If the gap between the stripper hole and the punch is too large, the discharge force will increase, causing the punch to pull out.
3. The rigidity of the punch or die frame is poor, and the punch is elastically deformed during punching, causing the punch to collide or get stuck with the stripper, increasing the unloading force and easily pulling out the punch.
4. The punch and die gap is too small, the working surface is rough, or the gap is sideways, which will increase the discharge force during punching and cause the punch to pull out.
5. When the punch is fixed with a low melting point alloy, there is no groove on the assembly side of the punch and the assembly hole of the punch fixing plate, which makes it easy to pull out the punch.
1. Why does gnawing occur during the processing of automobile stamping parts? How should it be prevented?
A bite is a touch blade. During the blanking process, a certain gap should be maintained between the die blades, and they should not collide with each other. There are four reasons for the collision of the blades.
1. Design: In terms of equipment, the punch is incorrect. If the punch is fixed by chiseling, it may cause the punch to loosen. Casting of low melting point alloys can also lead to punch loosening. The punching pressure is large, the punch root does not use a hard backing plate, and the lateral force of the punch is too large, which will cause the punch to loosen.
2. Molding: convex, concave mold or guide parts are not installed vertically.
3. The assembly of the upper and lower formwork, the fixed plate and the convex and concave formwork is not parallel.
The blanking gap is not uniform.
4. The installation of the punch does not meet the design requirements.
Second, the use of molds.
1. Repeated punching or stack punching, that is, stacking two or more blanks in a place where the blanks do not move for punching.
2. The scraps or blanking parts left on the mold are not removed in time.
Third, mold maintenance problems.
1. The wear of the mold parts is large, and the fitting clearance caused by the wear of the guide parts is too large, which cannot be repaired in time.
2. The mold maintenance assembly is loose.
In order to avoid die gnawing, a die with a guide should be used as much as possible, especially for a die with a small blanking gap. The fixing method of the punch should be carefully considered, and the manufacturing of the mold should be firm and reliable. The composite punching die should pay special attention to operate in strict accordance with the punching operation rules, clean the surface of the die in time, and avoid repeated punching and stacking. Strengthen the maintenance and management of molds to ensure that the molds are in good condition. Hope it helps readers.Read More →