METHOD FOR SEPARATING PIECE FROM SHEET BY PUNCHING

PURPOSE:To prevent occurrence of distortions in a sheet piece separated from a sheet and improve the productivity of the sheet piece, by punching each edge section of the sheet piece to be punched with small interval sections being left at the corner sections and cutting the small interval sections by fusion with a fixed electrode and movable electrodes. CONSTITUTION:Punching of punching holes 3 and 4 of a metallic sheet 1 is performed by means of a turret punch press, etc. At the time of this punching operation, small interval sections 2b are left at the corner sections of a sheet piece 2a. A fixed electrode 11 is fixed to the outer edge side of the sheet 1 and, at the same time, movable upper and lower electrodes 12 and 13 are put on and under the sheet 1. Then, the sheet piece 2a is held together under force by the movable electrodes 12, 13, and electricity is supplied across the electrode 11 and electrodes 12 and 13 while pressing the electrodes 12 and 13 against the sheet piece section 2a and the small interval sections 2b are cut by fusion. Therefore, the sheet piece 2a can be prevented from being distorted and scratched and, at the same time, its productivity can be improved.