Title:
METHOD FOR MANUFACTURING ENGINE POPPET VALVE
Document Type and Number:
WIPO Patent Application WO/2021/199190
Kind Code:
A1
Abstract:
This method is for manufacturing an engine poppet valve having an umbrella part and a shaft part integrated via a neck part the diameter of which increases toward the tip. The method comprises: an umbrella part manufacturing step for forming, by hot forging, an shaft umbrella intermediate product provided with an intermediate shaft part and an umbrella part integrated with the intermediate shaft part via the neck part; a stepped shaft part manufacturing step for forming, from the intermediate shaft part, a stepped shaft part provided with a first shaft part that, by performing cold drawing machining of press fitting a portion of the intermediate shaft part to a wire material introduction surface and the shaft material compression surface from a base end with respect to a hollow circular hole die having a shaft material introduction surface gradually tapered off toward the center axis and reducing holes at least partially having a shaft material compression surface continuous to the shaft material introduction surface and provided with a fixed inner diameter less than the outer diameter of the intermediate shaft part, has a diameter reduced, a stepped part that is formed by the shaft material introduction surface, and a second shaft part that is connected to the first shaft part via the stepped part with a non-reduced diameter; and a joining step for joining a shaft end part having an outer diameter equal to that of the first shaft part to the base end of the first shaft part.
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Inventors:
YOSHINO RYOUICHI (JP)
SATO DAIKI (JP)
SASAGAWA YUKI (JP)
SATO DAIKI (JP)
SASAGAWA YUKI (JP)
Application Number:
PCT/JP2020/014635
Publication Date:
October 07, 2021
Filing Date:
March 30, 2020
Export Citation:
Assignee:
NITTAN VALVA (JP)
International Classes:
F01L3/12; B21K1/22; F01L3/14; F01L3/20; F01L3/24
Domestic Patent References:
| WO2019180806A1 | 2019-09-26 |
Foreign References:
| JP4390291B1 | 2009-12-24 | |||
| JPH0696177B2 | 1994-11-30 | |||
| JP2016047537A | 2016-04-07 | |||
| JP2018041807W | 2018-11-12 |
Other References:
See also references of EP 4129525A4
Attorney, Agent or Firm:
YAGI Hidehito et al. (JP)
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