design of convex and concave die for Metal Stamping parts
The basic principles of metal stamping cutting edge size calculation:
The dimensional accuracy of the blanking part is mainly determined by the dimensional accuracy of the die edge, and the fair gap value of the die also depends on the die edge size and manufacturing accuracy. Correctly determining the size of the die edge and manufacturing tolerances is one of the main tasks in designing a blanking die. It can be found in production practice:
1. Because there is a gap between the convex and concave dies, the falling material or punched holes are tapered, and the large end size of the blanking part is the die size, and the small end size of the punching part is the die size.
2. In measurement and use, the blanking part is based on the large end size, and the diameter of the punching hole is based on the small end size.
3. When punching, the convex and concave dies must be in friction with the blanking part of the waste.
As an Auto stamping Exporter, the following principles must be taken into account when determining die edge size and manufacturing tolerances:
1. The size of the blanking part is determined by the size of the die, and the size of the hole when punching is determined by the size of the punch. Therefore, when designing the blanking die, the concave die is used as the reference, and clearance is taken on the convex die; when designing the punching die, the convex die is used as the reference, and clearance is taken on the concave die.
2. When determining die manufacturing tolerances, account should be taken of the part’s tolerances. If the precision of the cutting edge is too high (that is, the manufacturing tolerance is too small), it will make the mold difficult, increase the cost, and prolong the production cycle. Parts may diverge, which will reduce the life of the mold. The relationship between the precision of the parts and the precision of the mold manufacturing is shown in Table 2-1. If the parts are not marked with tolerances, the non-circular parts are processed according to the national standard “Non-fitting tolerance value” IT14 level, and the die can be manufactured according to IT11 level; for round parts, the mold can generally be manufactured according to IT7 ~ 6 levels. The dimensional tolerances of stamping parts shall be marked as one-way tolerances according to the principle of “entry body”. The deviation on the blanking part is zero and the lower deviation is negative; the upper deviation of the punching part is positive and the lower deviation is zero.
3. Considering the wear of the convex and concave die in punching, when designing the blanking die, the basic size of the concave die should be the smaller size of the dimensional tolerance range; when designing the punching die, the basic size of the convex die should take the workpiece hole size tolerance range. Larger size inside. In this way, when the convex and concave molds are worn to a certain extent, the qualified parts can still be punched out. Clearances of convex and concave die are taken as the least fair clearance values. Our company also has Aluminum Stamping Lids on sale. Welcome to consult.