| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a yoke of a universal joint by which the life of a die is prolonged by reducing fluctuation in loads applied to the die, and generation of burrs of a ridge line part connecting an arm part is suppressed. <P>SOLUTION: A yoke material 2A is formed by being restricted by an inner circumferential surface 421 of a die 42, and outer circumferential surfaces 431, 432 of a mandrel 43, and a preformed yoke material 2B is formed thereby. A coupling cylindrical part, a hole part, an arm part, a ridge line part, a chamfered part and a round chamfering are preformed on the preformed yoke material 2B. A gap is formed between a front end 231 of the arm part of the preformed yoke material 2B and a fore end 441 of a knock-out pin 44 when the preformed yoke material 2B is completed. Thus, even when the volume of the container material 2A is fluctuated, the loads applied to an upper die 3 and a lower die 4 are not fluctuated, and the life of the die is prolonged. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
