When the stamping material in precision stamping is soft and magnetic adsorption material, the bigger the size of the blanking step hole of the punching die is, it is easy to induce transverse friction resistance, and eventually lead to the blockage of the blanking hole.
When stamping processing red copper, aluminum and other low melting point soft thin material, stamping will make high-speed separation and quickly superimposed together punching waste, in the blanking surface of mutual melting phenomenon, punching waste is no longer a piece can be separated from the state, but the state of melting into a strip downward discharge. When blade design into a void, ladder hole, waste from effective wall constraint on the strings, the steps of the expanded hole had a curved space, the bend is different because of the friction coefficient of the wall around the edge induced, and the different friction coefficient is uneven by punch, concave die assembly clearance, die blade wall do not match the finish around the processing problems, When the bending head of strip waste touches the wall of the expanded step hole, unilateral friction resistance will cause transverse distortion of strip waste, and further lead to upsetting deformation of strip waste in the step hole, until the whole blanking hole is filled.
When stamping object is magnetic adsorption material, enlarge die blanking step hole size, and also can make punching waste, under the high speed stamping die after grinding, no refund do magnetic magnetic adsorption effect, in expanding the ladder hole back down when the adsorption in the hole wall and the gradually formed pile up on the ladder hole crisscross overlap each other aside phenomenon, Increasing the transverse force of punching waste, accumulated friction between the wall of the step hole, and finally affect the normal fall of punching waste, resulting in the blockage of the whole blanking hole.
The causes of blanking hole blockage in stamping process are generally above two kinds.