METHOD OF PRODUCING LAMINATED IRON CORES

摘要

A method of producing iron cores by punching out rotor iron core pieces and stator iron core pieces from one and the same thin metal sheet and laminating them, wherein the pole teeth of roughly punched-out stator iron core pieces are subjected to stable drawing by pressing on side of voids left by punching out the rotor iron core pieces, securing a sufficient punching allowance for punching out the front ends of the pole teeth on the inner diameter side of the stator iron core pieces to ensure trouble-free punching even when the gap between the stator and rotor iron core pieces is small, the laminated iron cores having little sheet surface unevenness which is due to pressing and having superior characteristics causing no disturbance in the flow of flux. The method comprises the steps of punching out rotor iron core pieces from a thin metal sheet and laminating them, roughly punching out the pole teeth (7) of the stator iron core pieces from the thin metal sheet from which the rotor pieces have been punched out, thinning the pole teeth (7) by pressing it at a plurality of positions, drawing the material to the punched-out side of the rotor iron core piece so as to form thin regions (10, 11), punching out the front ends (8) of the pole teeth constituting the inner diameter side of the stator iron core pieces, and punching out the outer shape of the stator iron core pieces and laminating them.