| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce cost of a forming device and an internal tooth member, and get the forming device and the internal tooth member smaller in size. SOLUTION: The device has a mandrel 78 a fixed member for fastening a raw material at a front edge of the mandrel 78, and a forming roller for deforming the raw material by pressing it against the mandrel 78. The mandrel 78 is composed of a main element part 16 and a ring 17 arranged adjoining to the main element 16 wherein the main element is equipped with a tooth die part 79 composed of plural grooves 21, both ends of which are kept opened. A peripheral edge part of a front end face of the ring is slanted backward. Since the mandrel 78 can be manufactured by a through forming method grinding processing, the cost of the forming device and the internal tooth member can be reduced. When a material in the groove 21 is pressed against the peripheral edge part, since a pressing stress is generated inside the ring 17, no chipping occurs at the peripheral end part.</p> |
