| 摘要 |
PURPOSE:To enable the inexpensive mass production of a titled ring by subjecting a tack welded ring formed by cutting a thin walled spiral hollow body by each one turn to beam welding while rotating the same by the axial center of rotation running the center of the cut face. CONSTITUTION:A thin walled spiral hollow body produced by a production device for a spiral hollow body by each one turn and the cut ends C thereof are tack welded to each other by beam welding to form a ring 14. The ring 14 is then grasped in a grasping part 11b in such a position where the center of a cut face of a cut end face C and the axial center at one end 11c of a revolving shaft part 11a are on the same horizontal line. The member 14 is rotated around the end 11c and the cut ends C are beam welded to each other by a laser 13d. In the stage of the beam welding to the cutt end C positioned on the inside of the ring 14, the shaft part 13a of a beam welder 13 is slid very slightly (e) and further the rotating position of the ring 14 is adjusted so that the laser beam 13d is radiated to the contact part. |
