Title:
DIE, METHOD OF MANUFACTURING STEPPED METAL TUBE, AND STEPPED METAL TUBE
Document Type and Number:
WIPO Patent Application WO/2006/025369
Kind Code:
A1
Abstract:
A die, a method of manufacturing a stepped metal tube, and the stepped metal tube. A through hole in the die comprises a bell, an approach, and a bearing in this order from an inlet side and having continuously formed inner surfaces. The diameter of the approach is (D1) at the inlet side and (D2) at the outlet side and gradually reduced from the inlet side to the outlet side, and meets the requirement of the expression (1). Also, the die half angle (R1) of the inner surface with a diameter of D3 = D2/0.97 is equal to or more than the die half angle (R2) of the inner surface on the outlet side of the inner surface of (D3), and an axial distance (LR) from the inner surface of (D3) and the inner surface of (D2) meets the requirement of the expression (2). The diameter of a through hole at the bearing is constant at (D2) and the length thereof is (LB), and they meet the requirement of the expression (3). 0.7 ≤ D2/D1 < 0.97 (1) 20 ≤ LR/(D3 - D2)/2 ≤ 115 (2) 0.3 ≤ LB/D2 ≤ 10 (3)
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Inventors:
OKUI TATSUYA (JP)
KURODA KOICHI (JP)
AKIYAMA MASAYOSHI (JP)
KURODA KOICHI (JP)
AKIYAMA MASAYOSHI (JP)
Application Number:
PCT/JP2005/015739
Publication Date:
March 09, 2006
Filing Date:
August 30, 2005
Export Citation:
Assignee:
SUMITOMO METAL IND (JP)
OKUI TATSUYA (JP)
KURODA KOICHI (JP)
AKIYAMA MASAYOSHI (JP)
OKUI TATSUYA (JP)
KURODA KOICHI (JP)
AKIYAMA MASAYOSHI (JP)
International Classes:
B21D41/04; B21C37/18
Foreign References:
| JPS5235629B2 | 1977-09-10 | |||
| JPH1099922A | 1998-04-21 | |||
| JP2002011518A | 2002-01-15 |
Other References:
See also references of EP 1785204A4
None
None
Attorney, Agent or Firm:
Ueba, Hidetoshi (4th Fl. Kadono Bldg., 2-1, Tenma 2-chome, Kita-k, Osaka-shi Osaka 43, JP)
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