Three Key Points of Continuous Die Drawing Mold
There are many types of products in the mold industry, among which the drawing die belongs to a type with higher technical content. Due to the following difficulties, it is difficult to stretch the mold: 1. Design and calculation; 2. Mold testing after mold design is completed. For designers, to design a reasonable stretching mold structure, they need to accumulate rich design experience.
The qualification of tensile parts is closely related to the selection of materials and presses, and the lubricating oil for tensile molds is also an important factor: 08 steel is the main representative of tensile material selection. The drawing die generally uses cold plate series such as 08Al, 08, 08F, 10, 15, and 20 steel. For designers, reasonable material selection has already made the stretching mold half successful.
For rotating and cylindrical deep drawn parts, the calculation method of cutting size is based on the principle of material volume unchanged, even if the material becomes thinner during the deep drawing process, its total volume will not change.
The calculation method for complex shaped drawing products can be quite cumbersome, as the shape of the drawing mold is accompanied by changes in material thickness. Even with the help of 3D software and simulation analysis software, it is difficult to achieve the expected cutting effect. To obtain the appropriate cutting size. Only the test piece can determine how much material is needed, and then design the structure of the stretching die and keep trying.
The stretching coefficient determines the number of steps required to stretch a product, and the stretching height and size of each step are calculated based on the stretching coefficient. Different stretching structures and processes have different stretching systems, which require reasonable selection based on actual products. The main factors affecting the tensile coefficient are: 1. The mechanical properties of the material (yield strength elastic deformation; tensile strength plastic deformation; elongation coefficient; cross-sectional shrinkage). 2. The relative thickness of the material. 3. Stretching time. 4. Stretch mode. 5. Die fillet radius. 6. The smoothness, lubrication conditions, and clearance of the stretching working surface. 7. Drawing speed.
If cracks appear in the tensile mold trial, you can try applying a little lubricant (rapeseed oil, soapy water) to the lower mold or covering a thin film on the surface material of the concave mold to achieve a certain effect.
Appropriate annealing heat treatment can improve the plasticity of the material, thereby reducing the number of parts that are stretched multiple times. After each stretching, hardening occurs, leading to a decrease in plasticity and various stretching problems.
