DIE FOR PUNCHING SHEET METAL AND SHEET METAL PUNCHING APPARATUS HAVING THE DIE

摘要

The present invention is directed to a die for punching sheet metal comprising: a first end face opposing sheet metal to be punched; a second end face opposing said first end face in an axial direction; a through hole having a first opening which is disposed on the first end face and through which a punch is inserted into the through hole and a second opening which is disposed on the second end face through which a punched scrap is discharged from the through hole; an inner peripheral surface defining said through hole; and an outer peripheral surface, said first end face extending in such a manner as to be inclined with respect to an axis of a punch, and said inner peripheral surface and said outer peripheral surface, respectively, extending in parallel to the axis of said punch, said first end face being contiguously connected at an inner end thereof to one end of the inner peripheral surface in the axial direction, said first end face and said inner peripheral surface being intersected to each other with an acute angle .theta. at the first opening of said through hole in said first end face, and said first end face being contiguously connected at an outer end thereof to one end of the outer peripheral surface in the axial direction. The die of the present invention avoids the usual problems associated with punching sheet metal with a plate thickness of 0.8 mm or more.