METHOD FOR MANUFACTURING METALLIC TUBE

摘要

PROBLEM TO BE SOLVED: To manufacture a metallic tube 7 excellent in dimensional accuracy easily and at a low cost. SOLUTION: This method has a U-bending stage E for forming a square metallic base stock 2 into a U-shape, and an O-bending stage F for bending this metallic base stock 2 formed into the U-shape into an O-shape. In the O-bending stage F, by using an O-bending pin for regulating the inside diameter of the metallic tube 7, the outside diameter of this O-bending pin is made smaller by a specified amount than the normal inside diameter of the metallic tube 7. Furthermore, a correcting stage for correcting the inside diameter and the outside diameter of this work by pressing the outer peripheral surface of a cylindrical work formed into the O-shape in the direction of diameter reduction and also pressing both end faces in the axial direction of the work in a direction in which they approach to each other is provided. COPYRIGHT: (C)2003,JPO