METHOD FOR MANUFACTURING VALVE FOR INTERNAL COMBUSTION ENGINE

Title:

METHOD FOR MANUFACTURING VALVE FOR INTERNAL COMBUSTION ENGINE

Document Type and Number:

WIPO Patent Application WO/2013/054437

Kind Code:

A1

Abstract:

A method for manufacturing a valve, having a primary forging step wherein a disk-shaped umbrella part is formed at the end part of a shaft, an excess thickness adjustment step wherein the thickness of the disk-shaped umbrella part is adjusted by cutting, and a secondary forging step wherein forging is performed to produce slip deformation at the edge part of the disk-shaped umbrella part, from the inner circumferential side to the outer circumferential side, thereby forming the umbrella face (16) of the valve. In the primary forging a tapered part (16a) is formed at the edge of the disk-shaped umbrella part, and in the excess thickness adjustment step only the front-surface side of the disk-shaped umbrella part is cut. The tapered part (16a) at the edge of the disk-shaped umbrella part is a surface layer part where fine forging flow lines are formed, and by means of the secondary forging the forging flow lines are made even finer, forming the umbrella face (16) of the valve, with the umbrella face having a sufficiently high hardness. The edge corner part of the disk-shaped umbrella part is not cut to a tapered shape, so raw material can be conserved and the time required for the excess thickness adjustment step can be reduced.

Inventors:

KURAHASHI KAZUNORI (JP)
MIKAMI MAIKU (JP)

Application Number:

PCT/JP2011/073652

Publication Date:

April 18, 2013

Filing Date:

October 14, 2011

Export Citation:

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Assignee:

NITTAN VALVA (JP)
KURAHASHI KAZUNORI (JP)
MIKAMI MAIKU (JP)

International Classes:

F01L3/20; B21K1/24

Domestic Patent References:

WO2011058793A1

2011-05-19

Foreign References:

JP2001115808A	2001-04-24
JP2001121239A	2001-05-08
JPH0861028A	1996-03-05

Other References: