发明名称 |
Method and tool for forming a tapered hole in a cylindrical work by punching extruding |
摘要 |
PCT No. PCT/JP95/01949 Sec. 371 Date Jun. 25, 1997 Sec. 102(e) Date Jun. 25, 1997 PCT Filed Sep. 27, 1995 PCT Pub. No. WO96/09904 PCT Pub. Date Apr. 4, 1996This invention provides a forming method capable of forming tapered through holes at once with a single pressing operation. A hole is formed in a work with a piercing punch 1 mounted on a press by using a small-diameter punching portion 1a formed on the distal end of the punch 1. A hole 11 formed at this time has a section with an open lower end portion by pressing. By using this hole 11 as a guide, a tapering portion 1b having a diameter slightly larger than the diameter of this hole and a tapered surface T forms a tapered surface on the inner surface of the hole 11 in accordance with plastic working. A "burr 3a" is formed on the edge of the hole 11 by this plastic working. Formation of this "burr 3a" is prevented with a pressure portion 1c formed on the piercing punch 1. When the above process is performed in a single pressing operation, a plurality of tapered through holes can be formed easily.
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申请公布号 |
US5816093(A) |
申请公布日期 |
1998.10.06 |
申请号 |
US19970809682 |
申请日期 |
1997.06.25 |
申请人 |
NITTO KOHKI CO., LTD. |
发明人 |
TAKEUCHI, HIROSATO;YASUDA, SHIGERU;KUBO, HARUO |
分类号 |
F16L21/00;B21C37/28;B21C37/29;B21D28/16;B21D28/24;B21D28/34;B21K1/00;(IPC1-7):B21D28/14;B21D28/28 |
主分类号 |
F16L21/00 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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