Knowledge of preventing bending and cracking of precision stamping parts

1. The law of U-shaped bending parts

U-shaped parts are processed by flat sheet materials, the material thickness is changed, the resilience decreases, and the fillet radius increases. Its bending law is related to two factors: the mechanical properties of the material, and the resilience angle varies with As the yield point increases, it increases, and decreases as the elastic modulus increases; relative to the bending radius R, the radius that the workpiece stretches in a specific direction, H is the height of the workpiece, the smaller the value of R/H, The larger the radius of the rounded area is, the rebound angle increases with the increase of R/H when other conditions are the same.

The U-shaped bending of the precision stamping parts factory has less resilience than the V-shaped bending, and the shape of the stamping parts is also complicated, and there are many things involved in each part, and the rebound is more difficult.

In the mold design, the U-curved concave and convex molds have a large gap, and the rebound of the parts after unloading will be relatively large, so it must be adjusted according to the degree of adhesion between the material and the mold.

• 1. When selecting materials, use materials with good surface quality as much as possible. If there are defects such as blanks, they must be repaired before stamping.
• 2. For relatively fragile materials, preheat and then bend, or use annealing to increase its plasticity, and then bend.
• 3. For thicker materials, if the structure is reasonable, slotting can be performed in the bending angle first, and then the bending process can be started.
• 4. When processing hardware precision stamping parts, the bending radius must be smaller than the small bending radius.
• 5. The curved line should be perpendicular to the fiber direction of the material.