Title:
MECHANICAL EXPANDER AND PRODUCTION METHOD FOR SEAMLESS STEEL PIPE
Document Type and Number:
WIPO Patent Application WO/2007/102602
Kind Code:
A1
Abstract:
[PROBLEMS] To improve the inner diameter size precision of the pipe end portion of
a seamless steel pipe to be hot-worked. [MEANS OF SOLVING PORBLEMS] A mechanical expander
in which a cone (2) and a die (1) are inserted into a pipe end portion to be pipe-expanded,
and the cone (2) is axially drawn toward the outside of the pipe with the die (1)
kept fixed at the pipe end portion, whereby the die (1) is radially and outwardly
spread out by a wedge action to pipe-expand the pipe end portion. A taper of which
the outer-periphery-surface radius is 1 mm larger, for example, at the pipe depth
end than at the pipe inlet side is formed on the outer periphery of the body (1a)
of the die (1). This mechanical expander is used to pipe-expand the pipe end portion
and produce a seamless steel pipe. [EFFECTS] When steel pipes are joined to each
other by circumferential welding at an installation site, excellent on-site
welding characteristics are delivered. A seamless steel pipe excellent in
pipe end size precision can be produced.
Inventors:
ARITA TSUTOMU (JP)
AKIYAMA MASAYOSHI (JP)
KURODA KOUICHI (JP)
OKUI TATSUYA (JP)
AKIYAMA MASAYOSHI (JP)
KURODA KOUICHI (JP)
OKUI TATSUYA (JP)
Application Number:
PCT/JP2007/054695
Publication Date:
September 13, 2007
Filing Date:
March 09, 2007
Export Citation:
Assignee:
SUMITOMO METAL IND (JP)
ARITA TSUTOMU (JP)
AKIYAMA MASAYOSHI (JP)
KURODA KOUICHI (JP)
OKUI TATSUYA (JP)
ARITA TSUTOMU (JP)
AKIYAMA MASAYOSHI (JP)
KURODA KOUICHI (JP)
OKUI TATSUYA (JP)
International Classes:
B21D41/02; B21C37/16
Foreign References:
| JPS59501197A | 1984-07-12 | |||
| JPH09285829A | 1997-11-04 | |||
| JP2820043B2 | 1998-11-05 | |||
| JP2900819B2 | 1999-06-02 |
Other References:
See also references of EP 1992428A4
Attorney, Agent or Firm:
SUGIOKA, Kanji et al. (Amagasaki Building 5-17-23, Higashinaniwa-ch, Amagasaki-shi Hyogo 92, JP)
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