Rolling of thread blank |
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| 申请号 | JP11517882 | 申请日 | 1982-07-01 | 公开(公告)号 | JPS594935A | 公开(公告)日 | 1984-01-11 |
| 申请人 | Nitto Seiko Co Ltd; | 发明人 | OKADA HIROYUKI; | ||||
| 摘要 | PURPOSE:To obtain a thread blank at high productivity and high material yield by small number of processes in manufacturing a thread blank having corners chamfered at the head from a preliminary thread material, by rolling the head of the preliminary material. CONSTITUTION:A preliminary thread material 4 having a columnar head 5 and leg 15 formed to specified size is supplied successively to the chamfer 14 of a fixed die 6a. With advance of a moving die 6b from the chamfer 14 to escape part 13, the head 5 enters recessed grooves 7 of dies 6a, 6b. When the die 6b advances and the head 5 arrives at a reduced part 17, the distance between the sides 7a and 7d of the dies becomes narrow and outer peripheral face of the head 5 is pressed, and the metal of a peripheral of the head is pushed out in the direction of upper and lower faces of the head. When the head 5 arrives at the parallel part 18, ceiling faces 7b, 7e and floor faces 7c, 7f resist against pushing out of the metal, and corners having minute chamfer are formed on the upper and lower faces of the head 5. | ||||||
| 权利要求 | |||||||
| 说明书全文 | |||||||
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