The problem of mold wear refers to the abnormal wear of the mold, which leads to the quality and precision of the drawing parts to be seriously reduced, and the normal service life of the mold is greatly shortened.
1. The wear parts of the drawing mold
(1) In the areas where the blank material flows more and the flow resistance is larger, such as the rounded corner and the deep convex pedestals on the surface of the concave mold, etc. Because of the large surface pressure, the wear and tear of these parts is also large. The wear and adhesion of the molds at these locations is the main cause of scratches and foreign matter bulges.
(2) In places where the thickness of the plate increases, the wear is also large. Because the thickness of the plate is increased, although no folds are generated in this stretched deformation zone, the surface pressure at this site will increase, and the adhesion and wear will also easily occur.
(3) In the area where folds are formed, the wear increases. The different parts of folds increase the surface pressure and cause attrition on the local surface of punch and mold. In general, folds are prone to occur due to the large depth of drawing and the large volume of material flow. The common influence of this factor and folds will make the wear more serious.
2. Measures to improve wear
(1)The clearance values of the convex and concave mold shall be taken according to the actual situation of the thickness change of the sheet metal. It can prevent local pressure buildup so as to reduce adhesion and wear.
(2) Correct lubrication. The addition of high-pressure additives in low-viscosity lubricants will play a significant role in reducing mold wear. Besides, correct and reasonable lubrication also improves the extension conditions, and sometimes reduces the folding phenomenon.
(3) Using the material with good wear resistance and proper heat treatment, so thar the mold has high hardness and wear resistance.
(4) Eliminate folds. By eliminating folds, the wear caused by folds is reduced, such as improving the shape and accuracy of the surface of the die, and properly arranging the protruding ledges.