Title:
MANDREL MILL AND METHOD FOR MANUFACTURING SEAMLESS PIPE
Document Type and Number:
WIPO Patent Application WO/2012/005287
Kind Code:
A1
Abstract:
Provided is a mandrel mill which has three hole-type rolls disposed at each of a plurality of rolling stands and without increase in facility costs or degradation in maintainability, is capable of sufficiently preventing a phenomenon in which a mandrel bar cannot be withdrawn from a pipe that has been drawn and rolled. The mandrel mill is provided with the plurality of rolling stands in a manner such that the three hole-type rolls (R) at each rolling stand are located in the draft directions at an angle of 120 degrees relative to each other and the draft directions of the hole-type rolls (R) are alternately shifted by 60 degrees between adjacent rolling stands. The mandrel mill is characterized in that the central angle θ of the arc that forms the groove bottom profile of the hole-type rolls (R) located at least at a first rolling stand and a second rolling stand is set at less than 60 degrees.
Inventors:
YAMANE Akihito (5-33, Kitahama 4-chome, Chuo-ku, Osaka-sh, Osaka 41, 〒5410041, JP)
Application Number:
JP2011/065465
Publication Date:
January 12, 2012
Filing Date:
July 06, 2011
Export Citation:
Assignee:
Sumitomo Metal Industries, Ltd. (5-33, Kitahama 4-chome Chuo-ku, Osaka-sh, Osaka 41, 〒5410041, JP)
住友金属工業株式会社 (〒41 大阪府大阪市中央区北浜４丁目５番３３号 Osaka, 〒5410041, JP)
住友金属工業株式会社 (〒41 大阪府大阪市中央区北浜４丁目５番３３号 Osaka, 〒5410041, JP)
International Classes:
B21B17/02; B21B27/02
Attorney, Agent or Firm:
OHNAKA Minoru (Daiichijuken Nagahoribashi-ekimae bldg. 4F, 3-6 Minamisemba 2-chome, Chuo-ku, Osaka-sh, Osaka 81, 〒5420081, JP)
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Claims: