| 摘要 |
PURPOSE:To produce easily and inexpensively a valve body which can increase the flow rate of oil with high accuracy by inserting a forging die having a male die corresponding to the groove to be formed into an annular blank material and pressing successively said male die in the position to be formed with said groove thereby forging the groove. CONSTITUTION:A foging die 8 fitted and projected on a shaft-like member 9 with a male die 10 corresponding to the groove to be formed in a valve body is horizontally supported by means of supports 6, 7 erected on a base 5. An annular blank material 11 prior to forming of the groove is fitted circumferentially on the die 8, and an annular cover 12 is fitted externally on the material 11. A pressure P is exerted on the material 11 from the outside of the cover 12 in the position corresponding to the die 10 to form a groove 3 and thereafter the material 11 is rotated by each prescribed angle and the adjacent grooves 3 are successively forged like 3A-3H. The die 10 is again pressed to the first groove 3A to trim the shape of the groove 3A, whereby the accuracy of a valve body 1 is improved. The groove 3B, etc. which are formed later are further subjected to trimming according to need. |
