Factors that affect the amount of springback in precision stamping and bending processing 'hardware'

The factors that affect the springback of precision stamping and bending processing include the material of the part, the thickness of the plate, the punching force, and the size and shape of the die. (1) The radius of curvature of the punch. The amount of springback increases with the increase of the radius of curvature, and decreases with the decrease of the radius of curvature. Although there are slight differences due to different materials, it is generally appropriate to select the thickness of the plate below. At the same time, the small radius of curvature of the bent sheet must also be considered. (2) The fillet radius of the die shoulder is too small. If the radius of the rounded corner of the die shoulder is too large, the part will open outwards, and if it is too small, the parts will tilt inward. Generally choose 2 to 4 times the thickness of the plate. (3) Bending depth. The bending depth is small and the opening is large inside and outside, and the opening to the outside decreases as the depth increases. Generally, the bending depth should be more than 4 times the plate thickness. (4) The gap between convex and concave touch. When the gap between the convex and concave molds is larger than the thickness of the plate, the sheet material cannot fit well on the convex mold. The larger the rounded radius of the punch, the greater the amount of springback. On the contrary, if the gap is too small, the springback is almost eliminated, but it turns into an inward tilt. Generally, the gap is smaller than the thickness of the plate by 0. O2-O. 05mm is appropriate. Because of the existence of the above-mentioned influences, if we comprehensively examine these factors and the nature of rebound, it is easy to find the reason for the occurrence of rebound, and then stop the reason. The fundamental reason for the springback of precision stamping processing is that the bending part is subjected to uneven stress after the material is bent. If this part of the uneven stress is turned into a uniform stress, even if the entire section is full of compressive stress or all of tensile stress, the amount of springback can be reduced. However, some parts have special requirements for deformation, such as not suitable for indentation, which requires appropriate solutions in design and process. For this kind of parts, it is advisable to adopt the shape of convex and concave molds, which can also have a small springback.