Title:
PIERCING MACHINE, MANDREL BAR, AND METHOD FOR MANUFACTURING SEAMLESS METALLIC TUBE USING SAME
Document Type and Number:
WIPO Patent Application WO/2019/107443
Kind Code:
A1
Abstract:
Provided is a piercing machine capable of suppressing the temperature difference between a front end section and a rear end section of a hollow element tube following piercing/rolling or stretching/rolling. A mandrel bar (3) of a piercing machine (10) comprises: a bar body (31); a cooling liquid channel (34) which is formed in the bar body (31) and through which a cooling liquid flows; an inner surface cooling mechanism (340) which is disposed in a cooling region (32) and connected to the cooling liquid channel (34), and which cools an inner surface section of a hollow element tube (50) within the cooling region (32) by spraying the cooling liquid to the outside of the bar body (31) during the piercing/rolling or stretching/rolling; and an inner surface closing mechanism (350) which is disposed behind and close to the cooling region (32), and which during the piercing/rolling or stretching/rolling prevents the cooling liquid sprayed to the outside of the bar body (31) from contacting an inner surface section of the hollow element tube (50) positioned behind the cooling region (32).
Inventors:
OBE HARUKA (JP)
SAKAMOTO AKIHIRO (JP)
DAIMON YASUHIKO (JP)
SAKAMOTO AKIHIRO (JP)
DAIMON YASUHIKO (JP)
Application Number:
PCT/JP2018/043858
Publication Date:
June 06, 2019
Filing Date:
November 28, 2018
Export Citation:
Assignee:
NIPPON STEEL CORP (JP)
International Classes:
B21B19/04
Foreign References:
| JP2017013102A | 2017-01-19 | |||
| JPS5939407A | 1984-03-03 | |||
| JPH0399708A | 1991-04-24 | |||
| JP2017013102A | 2017-01-19 |
Other References:
See also references of EP 3718655A4
Attorney, Agent or Firm:
ASCEND IP LAW FIRM (JP)
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