PRODUCTION OF THICK SQUARE STEEL PIPE FOR CONNECTION

• Main Authors: NAKAGAWA TOSHIHIKO, ICHII SHINJI
• Format: Patent
• Language: English
• Published: 14.05.1996
• Edition: 6
• Subjects: AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKINGWITHOUT ESSENTIALLY REMOVING MATERIAL; MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES,OTHERWISE THAN BY ROLLING; MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVINGMATERIAL; PERFORMING OPERATIONS; PUNCHING METAL; TRANSPORTING; WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS ORPROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL

PURPOSE: To easily obtain a connection steel pipe which is thick and is small in the radius of curvature in corner parts at a low cost by heating a thick steel pipe to a recrystallization temp. or above, arranging dies in four directions perpendicular to each other of its outer peripheral surface and simultaneously moving the dies toward the pipe axis from four directions, then extruding the pipe. CONSTITUTION: Four pieces of the dies 53 are arranged perpendicular to each other. A work P is heated to the recrystallization temp. or above and is arranged at the center of four pieces of the dies 53. The dies 53 are moved simultaneously from the four directions toward the pipe axis of the work P. The movement stops in the contacting state of the chamfered parts of the dies 53 and the molding is completed. Large compressive force acts on the work P from the respective sides toward the corner parts and, therefore, the corner parts are formed thick and simultaneously, the corner parts bulge outside, thereby forming a sharp sectional shape of a small radius of curvature.