| 摘要 |
PROBLEM TO BE SOLVED: To provide a rolling die with which a shaft component having a ball-like part such as a ball joint is formed inexpensively, highly precisely in a short period of time. SOLUTION: This rolling die 1 is composed of a pair of dies 1a, 1b having long forming surfaces 2a, 2b which are opposed to each other and have a mutually symmetric cross-sectional shape. the forming surfaces 2a, 2b of such dies 1a, 1b have a protruded line 5 having an approximately chevron cross section which bites into the midway of a columnar part 17 of the base stock 14 for shafts and a circular-arc surface 8 adjacent to the protruded line symmetrically along the longitudinal direction in the forming starting part S1, the protruded lines 5, 7 and a curved surface 9 which is adjacent to them and with which the columnar part 17 is pressed into a radius shape symmetrically in the forming midway part S2 and also a circular-arc groove 11 symmetrically having an approximately semicircular cross section for pressing the protruded line 7 and the nose side and the intermediate part respectively into a radius shape oppositely in the forming ending part S3. COPYRIGHT: (C)2007,JPO&INPIT |
