Key points of designing metal stamping and drawing die by die manufacturers

Mold prices of mold manufacturers In the design and processing of metal stamping and drawing dies, continuous drawing dies are difficult to do. In professional books and traditional teaching materials, we simply introduce the material development, stretching coefficient, stretching process, stretching gap, etc. of single process stretching die. Generally, they are relatively large parts, and continuous stretching is also based on the principle of single process stretching die. However, in the design and processing practice, there are many technical difficulties that need to be adapted for the continuous drawing die.

Process of Continuous Drawing Die

First of all, because most continuous drawing dies are connected by strips, during the whole production process, the strips can not be deformed, but also have enough strength to ensure accurate feeding. This requires a reasonable strip arrangement, which is the first step of the design, the discharge strip. During the nesting belt, the unfolded size of the product shall be accurately calculated. At the same time, the margin for lapping and blanking shall be reserved. The reasonable arrangement direction (whether the product is arranged horizontally or vertically) shall be selected. The stretching direction (pull up or pull down) shall be determined. Then the length and lapping method of the product lapping shall be calculated, including spider type, triangular type, and economical type,

Process of continuous drawing die

After determining the strip arrangement, it is necessary to calculate the drawing process, that is, how many drawing passes are needed to complete the Z final forming of the product. The stretching process depends on the stretching coefficient. We reasonably determine the stretching process according to the theory and the elongation of the material. Here, we need rich experience. The stretching coefficient is basically 0.55 in the first step, 0.65 in the second step, and 0.75 in the third step...., Of course, there are differences between stainless steel materials and copper materials in terms of coefficients. In addition, considering the difference between continuous stretching and single stretching, there is generally a guide plate for single stretching. Continuous stretching is empty stretching. The guide plate not only plays a positioning role, but also plays a guiding role in the stretching process, so as to prevent the product mouth from shrinking and deforming too quickly. All empty drawing in the continuous drawing die is natural shrinkage deformation, so if the drawing deformation is small, the transition should not be too large, that is, the drawing coefficient should be larger, and the drawing process should be more than the single process drawing.

Design Skills of Continuous Drawing Die

During the arrangement of stretching processes, 2-3 more steps should be reserved according to the theoretical design to prevent the designed process from failing to meet the needs of product stretching, that is, to reserve space for change.

After the process is determined, the stretching gap is different for different materials. For details, refer to the mold technical data. However, for the clearance between the punch and the die of the continuous drawing die, the factor of material thinning in the drawing process should be considered, especially for the thin material drawing. The drawing parts with high surface demand need to be thinned or stretched with zero clearance.

Structure of continuous drawing die

What needs to be determined is a reasonable die structure. Now the structure of metal stamping and drawing dies is more and more advanced, including an ordinary 8-plate structure, a down stripping hard guide structure, and a neutral up and down stripping structure.