Title:
FORGING DIE AND UPSET FORGING METHOD
Document Type and Number:
WIPO Patent Application WO/1998/047646
Kind Code:
A1
Abstract:
A forging die for upset forging a material (30) placed in a cavity (15b) of a drag (4) between the upper punch (8) of a cope (2) fitted to a slide (1) and the lower punch (16) of the drag (4) installed on a bolster (3), wherein an upper pin (9) and a lower pin (17), in each of which one end can freely protrude from or retract into the respective end face of each of the upper punch (8) and the lower punch (16), are provided within the upper punch (8) and the lower punch (16) so as to be freely movable vertically, and back pressure applying means are provided at the other end of each of the upper pin (9) and the lower pin (17) to apply back pressure to the upper pin (9) and the lower pin (17) respectively during forging and to remove the back pressure immediately before the cavity (15b) is filled with the material (30); and an upset forging method using such a forging die. The apparatus and method help reduce the forming load and thereby extend the durability of the die because the back pressure on the upper pin (9) and the lower pin (17) is removed when the cavity (15b) has become totally closed.
Inventors:
ANDO HIROYUKI (JP)
MATSUMOTO ISAMU (JP)
YAMAMOTO AKIRA (JP)
ISHIHARA YOSHIHIRO (JP)
MATSUMOTO ISAMU (JP)
YAMAMOTO AKIRA (JP)
ISHIHARA YOSHIHIRO (JP)
Application Number:
PCT/JP1998/001858
Publication Date:
October 29, 1998
Filing Date:
April 22, 1998
Export Citation:
Assignee:
KOMATSU IND CORP (JP)
NICHIDAI CORP (JP)
ANDO HIROYUKI (JP)
MATSUMOTO ISAMU (JP)
YAMAMOTO AKIRA (JP)
ISHIHARA YOSHIHIRO (JP)
NICHIDAI CORP (JP)
ANDO HIROYUKI (JP)
MATSUMOTO ISAMU (JP)
YAMAMOTO AKIRA (JP)
ISHIHARA YOSHIHIRO (JP)
International Classes:
B21J5/02; B21J13/02; B21J13/03; B21J13/14; B21K1/30; (IPC1-7): B21J13/02
Foreign References:
| JPH0999337A | 1997-04-15 | |||
| JPH04294838A | 1992-10-19 |
Attorney, Agent or Firm:
Hamamoto, Tadashi (5-16 Toranomom 1-chom, Minato-ku Tokyo, JP)
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