Title:
METHOD FOR MANUFACTURING VALVE UMBRELLA PORTION OF HOLLOW ENGINE VALVE, PRESS DEVICE OF VALVE UMBRELLA PORTION OF HOLLOW ENGINE VALVE, AND HOLLOW ENGINE VALVE
Document Type and Number:
WIPO Patent Application WO/2011/077776
Kind Code:
A1
Abstract:
Conventionally, in hot forging of a valve umbrella portion of a hollow engine valve, poor finish accuracy has been provided, and in cold forging thereof, materials which can be used have been restricted. In addition, in the cold forging and the known hot forging, the number of steps for drawing is increased, which requires a large number of steps for intermediate heating processes such as annealing, with the result that the poor workability has been obtained. In view of this, a semi-finished product having a hollow and an expansion diameter portion is manufactured in advance (first step), and a press device for folding an outer cylinder (4) and an inner cylinder (5) around an entire die set (DS) is used, thereby performing drawing with a body of the semi-finished product the center in a constant temperature atmosphere at any temperature between a room temperature and 870ºC (second step).
Inventors:
YOSHIMURA HYOJI (JP)
Application Number:
PCT/JP2010/061933
Publication Date:
June 30, 2011
Filing Date:
July 15, 2010
Export Citation:
Assignee:
MITSUBISHI HEAVY IND LTD (JP)
YOSHIMURA CO (JP)
YOSHIMURA HYOJI (JP)
YOSHIMURA CO (JP)
YOSHIMURA HYOJI (JP)
International Classes:
B21K1/22; B21J5/06; B21J5/08; F01L3/20; F01L3/24
Foreign References:
| JPH07208127A | 1995-08-08 | |||
| JPH07102917A | 1995-04-18 | |||
| JP2001225139A | 2001-08-21 | |||
| JP4390291B1 | 2009-12-24 |
Other References:
See also references of EP 2517806A4
"Heat treatment of steel, revised 5th edition", 1979, MARUZEN CO., LTD.
W. C. LESLIE: "The Physical Metallurgy of Steels", 1987, MARUZEN CO., LTD.
"Heat treatment of steel, revised 5th edition", 1979, MARUZEN CO., LTD.
W. C. LESLIE: "The Physical Metallurgy of Steels", 1987, MARUZEN CO., LTD.
Attorney, Agent or Firm:
MITSUISHI Toshiro et al. (JP)
Toshiro Mitsuishi (JP)
Toshiro Mitsuishi (JP)
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