Title:
PUNCH FOR COLD BACKWARD EXTRUSION FORGING
Document Type and Number:
WIPO Patent Application WO/2012/086573
Kind Code:
A1
Abstract:
A punch (1) comprises a molding land part (2) formed parallel to a punch axis (7), a molding R part (3) having an arc-shaped cross-section and formed continuously with the molding land part (2) on the front end side from the molding land part (2), and a recess part (5) formed on the base end side from the molding land part (2) and having a smaller diameter than the molding land part (2). The Rockwell hardness (HRF) of a material (20) is within the range of 65-105. The curvature radius (R) of the molding R part (3) of the punch (1) is larger than the thickness (L) of a cylindrical peripheral wall part (21) of a forged product (25). The length (B) of the molding land part (2) of the punch (1) is within the range of 0.05-0.15 mm. The recess width (C) with respect to the molding land part (2) of the recess part (5) of the punch (1) is within the range of 0.15-1.0 mm.
Inventors:
NATSUI MASAYUKI (JP)
Application Number:
PCT/JP2011/079319
Publication Date:
June 28, 2012
Filing Date:
December 19, 2011
Export Citation:
Assignee:
SHOWA DENKO KK (JP)
NATSUI MASAYUKI (JP)
NATSUI MASAYUKI (JP)
International Classes:
B21J13/02; B21J5/06; B21K21/14
Foreign References:
| JPH0663681A | 1994-03-08 | |||
| JPH06285579A | 1994-10-11 | |||
| JP2000218336A | 2000-08-08 | |||
| JPS63268530A | 1988-11-07 |
Other References:
"Press forming die need to know, Second Edition", 10 March 1980, JAPAN MACHINIST CORP, pages: 85 - 92
ROCKWELL HARDNESS EXAMINATION- EXAMINATION METHOD, 2005, pages Z2245
ROCKWELL HARDNESS EXAMINATION- EXAMINATION METHOD, 2005, pages Z2245
Attorney, Agent or Firm:
SHIMIZU Yoshihito et al. (JP)
Yoshihito Shimizu (JP)
Yoshihito Shimizu (JP)
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Claims: