PUNCHING METHOD, PUNCHING DEVICE, AND METHOD FOR MANUFACTURING LAMINATED CORE

摘要

The thickness of an electromagnetic steel sheet is set to be no more than 0.35 mm, Vickers hardness (1 kg test force) to be 150-400, and mean crystal grain diameter to be 50-250 µm. Clearance a for a die 3 is set to be at least 7% of the minimum thickness of the thicknesses of multiple electromagnetic steel sheets and not more than 7% of the total thickness of the multiple electromagnetic steel sheets. The pressing force exerted by sheet pressers 8 of the die 3 on the electromagnetic steel sheets is set to be at least 0.10 MPa. Under conditions in which all of said conditions are satisfied, the stacked multiple electromagnetic steel sheets are punched simultaneously with the die 3.