FORGING DIE AND ITS WORKING METHOD, GEAR FORGING DEVICE AND GEAR FORGING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a forging die and its working method capable of forming a helical gear which suppress the difference of helix angles generated on tooth faces at both sides of a plurality of spiral tooth ridges, and also to provide a gear forging device and a gear forging method.;SOLUTION: The forging die 2 is used for carrying out the cold closed-die forging of the helical gear. The forging die 2 has a forming hole 21 having the plurality of spiral tooth ridges 22. The forging die 2 is formed by mutually differentiating the helix angle θ1 of one tooth face 221 located at one position of the circumferential direction C of the forming hole 21 and the helix angle θ2 of the other tooth face 222 located at the other position of the circumferential direction C of the forming hole 21 at the plurality of the tooth ridges 22.;COPYRIGHT: (C)2009,JPO&INPIT