| 摘要 |
PURPOSE:To manufacture an electric welded steel pipe having no defect by calculating the torsion quantity of a welding joint part from a detected camber quantity, and cutting exactly a seam part by controlling a bead cutting position, in a process of executing the seam welding by forming a continuous feed strip to a shape of a round pipe. CONSTITUTION:A camber quantity thetas of a band plate 10 whose both ends have been trimmed 14, of a continuous feed strip is detected 15, and an angle of torsion alphas after seaming is calculated by a prescribed expression by a central processor 13. When its camber part passes through cylindrical shape forming parts 16-28 and is brought to high frequency heating welding, and the inside and the outside of a bead are cut 32, the cutting is executed by shifting cutting devices 32a, 32b by the angle of torsion alphas. The seam part is always cut exactly, and an electric welded pipe becomes a product having no defect. |
