APPARATUS AND METHOD FOR FORMING STEEL PIPE AND MANUFACTURING EQUIPMENT TRAIN

摘要

PROBLEM TO BE SOLVED: To provide a welded steel pipe the dimensional accuracy of which is improved by suppressing an angular shape generated at the press reducing point of a press. SOLUTION: This forming apparatus of the steel pipe is constituted so as to manufacture an open pipe by forming the steel sheet of a base stock with a press. This forming apparatus is provided with a punch having a projecting part for pressing the steel sheet from above and a die having a concave part for receiving the steel sheet pressed with the punch. This forming apparatus has a counter punch for pressing the steel sheet to the side of the punch by being projected from the side of the die when the steel sheet is pressed with the punch. This forming apparatus has a controller for controlling the pressing pressure to the steel sheet of the counter punch at not less than a specified value. COPYRIGHT: (C)2004,JPO&NCIPI