METHOD FOR FORMING GEAR-SHAPED MEMBER WITH BOSS AND THIS MEMBER

PROBLEM TO BE SOLVED: To provide a forming method with which a gear-shaped member with a boss can be formed in a high producing efficiency and at a low cost by applying chamfering on a tooth end part of the gear part during one series of working processes without separately arranging a working process for applying the chamfering. SOLUTION: This forming method comprises a first process, in which the boss part 6 is formed by applying a rear part extrusion-working at the one end side of a metal-made blank 10 and simultaneously the chamfered part P is formed by applying a front part extrusion-working at the other end side of the metal-made blank, and a second process, in which the gear part 8 in which a plurality of teeth 8a are continuously formed from the chamfered part toward the one end side, is formed by further applying the front part extrusion-working in the extrusion-remaining zone of the metal-made blank finished with the first process. The metal-made blank is constituted as the gear-shaped member 2 with the boss in which the boss part is formed at the one end side to a flange 4 and the gear part is continuously formed from the chamfered part at the other end side by applying the first and the second processes. COPYRIGHT: (C)2005,JPO&NCIPI