METHOD FOR STRAIGHTENING METALLIC TUBE, STRAIGHTENING ROLL AND MANUFACTURING APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide a metallic tube having high roundness and high straightness at a low cost by continuously performing a finishing process in the manufacturing process of an electric resistance welded tube, maintaining high productivity and realizing the combination of rolls. SOLUTION: This straightening method of a metallic tube is a straightening method by which hourglass-shaped rolls the projection of a roll caliber of which to the cross section of the tube is a circular arc and which have the roll caliber the radius of the projected circular arc of which is freely changeable by adjusting an angle formed by the roll axis and the axial line of the tube are adopted, a plurality of the hourglass-shaped rolls are arranged in the circumferential direction of the outer surface of the metallic tube and the reduction is added to the outside diameter of the tube while revolving these rolls around the tube axis. COPYRIGHT: (C)2004,JPO&NCIPI