Title:
HOLLOW SHAFT
Document Type and Number:
WIPO Patent Application WO/2020/189763
Kind Code:
A1
Abstract:
Provided is a hollow shaft comprising: a cylindrical body part (6); and a tip throttle part (7) coaxially integrated to one end of the body part (6) and made to have a smaller diameter than the body part (6) by throttle processing, wherein the inner circumferential surface (6i) of the body part (6), and the inner circumferential surface (7bi) of a base portion (7b) of the tip throttle part (7) extending to one end of the body part (6) are cut-surfaces cut before throttle processing, and the inner circumferential surface (7ai) of a tip portion (7a) extending to the tip side of the base portion (7b) of the tip throttle part (7) is a non-cut surface. Accordingly, a predetermined small inner diameter can be obtained while reducing the throttle ratio of the tip throttle part, the hollow shaft can be molded with high dimensional accuracy, and a stress concentration associated with throttle processing at the boundary between the tip throttle part and the cylindrical body part can be suppressed, thereby increasing the rigidity and strength of the hollow shaft.
Inventors:
MURATA SHINICHI (JP)
Application Number:
PCT/JP2020/012347
Publication Date:
September 24, 2020
Filing Date:
March 19, 2020
Export Citation:
Assignee:
MUSASHI SEIMITSU KOGYO KK (JP)
International Classes:
B21D41/04; B21C37/16; B21D51/10; B23B5/38; B23P23/04
Foreign References:
| JPS638859B2 | 1988-02-24 | |||
| JPH0356813B2 | 1991-08-29 | |||
| JP2001246524A | 2001-09-11 | |||
| JPH0523881B2 | 1993-04-06 | |||
| US20110209802A1 | 2011-09-01 |
Attorney, Agent or Firm:
OCHIAI & CO. (JP)
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