| 摘要 |
PURPOSE:To improve the yield of the material for a commutator of a motor and to simplify the manufacturing steps of the commutator by disposing and axially pressing a cylindrical blank, and extrusion molding the projected strips for securing commutator pieces onto the inner peripheral surface of the blank. CONSTITUTION:A cylindrical metallic material 1 is inserted into a die 12, and a slotted die 16 is inserted into the inner peripheral side of the material 1. Then, a sawging punch 15 is lowered from above to press the material 1 axially, thereby plastically deforming the inner peripheral surface of the material 1 toward the die 16, and projected strips 3b for securing commutator pieces are formed. In this case, the cylindrical port of the material 1 is molded in the die of a terminal piece for wiring a commutator, and the manufacturing steps are simplified. |
