During the stamping die design process, determining the total clearance of the die is a critical step in ensuring the best fit between the punch and die.
The stamping die gap has a significant impact on the quality of stamped parts, die life, and energy consumption during the stamping process. Reasonable clearance can reduce friction and energy consumption while ensuring the precision and surface quality of stamping parts.
When determining the die gap, it is necessary to comprehensively consider the properties of the material, the thickness of the stamped part, the precision requirements of the die, and the characteristics of the stamping process. Generally speaking, the gap value should be within a reasonable range, neither too large nor too small.
For most iron sheet materials, the gap value is usually calculated based on the thickness of the material. For example, when the material thickness is 0.5 mm to 3 mm, the gap value can be calculated using 16% of the material thickness. For soft materials (such as copper, iron, aluminum) and hard materials (such as stainless steel, steel with high carbon content), the calculation method of the gap value may be different and needs to be considered separately.
During the stamping process, the material deforms elastically. Therefore, when determining the gap, the elastic recovery of the material also needs to be considered. If the gap is too small, the material may rub against the die when it springs back, causing die wear and deterioration in the surface quality of the stamped part.
In addition to theoretical calculations, the rationality of the gap value can also be verified by experimental methods. For example, you can perform a paper cut test and thickness gauge measurement, or observe the bright band and burr of the stamped part to evaluate whether the gap value is appropriate.
The mold will wear during use, so the wear of the stamping die also needs to be considered when determining the gap. In order to extend the service life of the mold, the gap value can be appropriately increased to accommodate the wear.
In actual design, it may be necessary to comprehensively adjust and optimize the gap value according to specific circumstances. For example, the gap fit effect can be further improved by adjusting the structure of the stamping die, material selection, or stamping process parameters.
