Title:
METHOD FOR MANUFACTURING HOLLOW ENGINE VALVE
Document Type and Number:
WIPO Patent Application WO/2020/004286
Kind Code:
A1
Abstract:
Provided is a method for manufacturing a hollow engine valve, whereby the surface state of an inside surface for forming a hollow hole is satisfactory, and the volume of the hollow hole can be increased. This manufacturing method is provided with a forging step (S3) for obtaining an intermediate component (7) provided with a cylindrical part (8B) and a half-umbrella-shaped part (9B) continuous with a shaft-end side of the cylindrical part by a forging process, a heat treatment step (S4) for heat treating the intermediate component for a heating retention time (t2) determined in accordance with the wall thickness (t) of the cylindrical part (8B) to soften the intermediate components, a spinning step (S5) for elongating the cylindrical part of the heat-treated intermediate component in the axial direction by a spinning process, and a necking step (S6) for forming a shaft part (2) and an umbrella-shaped part (3) by reducing the diameter of the axially elongated cylindrical part by a drawing process.
Inventors:
IKEDA TOSHIO (JP)
KIMURA MORITOSHI (JP)
WATANABE YUTAKA (JP)
KIMURA MORITOSHI (JP)
WATANABE YUTAKA (JP)
Application Number:
PCT/JP2019/024806
Publication Date:
January 02, 2020
Filing Date:
June 21, 2019
Export Citation:
Assignee:
TOA FORGING CO LTD (JP)
International Classes:
B21K1/22; B21D22/16; B21D53/10; B21J1/04; B21J1/06; B21J5/06; B21J5/08; C21D9/00
Domestic Patent References:
| WO2011104903A1 | 2011-09-01 |
Foreign References:
| JP2012197718A | 2012-10-18 | |||
| JPH11117020A | 1999-04-27 | |||
| JPH04193912A | 1992-07-14 | |||
| JP2003001366A | 2003-01-07 | |||
| CN102728690A | 2012-10-17 | |||
| CN106180341A | 2016-12-07 |
Other References:
See also references of EP 3815811A4
Attorney, Agent or Firm:
KOJIMA Seiji (JP)
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