When the stamping material in precision stamping is soft and magnetic adsorption material, the larger the size of the blanking step hole of the punching die is, it is easy to induce lateral frictional resistance, which eventually leads to the blockage of the blanking hole.
When stamping and processing low melting point soft thin materials such as copper and aluminum, the punching wastes that are separated at high speed and quickly overlapped together will be fused together on the punching surface. In the state that can be separated, it is discharged downwards in the state of being fused into a strip. When the cutting edge is designed with a through-hole stepped hole, the strip waste that escapes the constraint of the effective cutting edge wall has a bending space in the enlarged stepped hole, and the bending is induced by the different friction coefficients around the cutting edge wall. , and the difference in friction coefficient is caused by the uneven assembly gap of punch and die, and the uneven finish around the edge wall of die. , the unilateral frictional resistance will cause the strip-shaped waste to be distorted laterally, which will further lead to the upsetting deformation of the strip-shaped waste in the stepped hole until the entire blanking hole is filled.
When the stamping object is a magnetic adsorption material, the die enlarges the size of the blanking step hole, and the punching waste under high-speed stamping will also be affected by the magnetic adsorption force that does not fully retreat after the die is sharpened. When the medium rolls down, it is adsorbed to the hole wall, and gradually accumulates to form a mutual shelving phenomenon in the stepped hole, which continuously increases the lateral force of the punching waste, and accumulates the friction force between the hole wall of the stepped hole, and finally It affects the normal falling of punching waste and causes the entire blanking hole to be blocked.
The reasons for the blockage of blanking holes in stamping processing are roughly the above two.