| 摘要 |
PURPOSE:To provide a tack welding and straightening device for steel pipes which straightens offsets and stabilizes tack welding quality by constituting the same in such a way that the edge-joined parts are forced upward from the inside of the steel pipe. CONSTITUTION:In using this tack welding and straightening device, particularly in the case in which offsets cannot be eliminated with a cage forming device, an operating cylinder 17 is started upon arrival of a steel pipe 1 at the vicinity of a welding torch 7, by which a piston rod 17a is extended. Consequently a straightening roller 21 is forced upward toward the edge-joined parts of the pipe 1 shown by imaginary lines. At this time, a guide reaction roll 16 serves as a reaction part. The steel pipe edges produced of level difference is forced upward, by which reaction R is given to the pipe 1. As a result, the offsets are corrected by this coupled with the effect of the cage forming device. In this case, the forcing tension and working distance by the roller 21 are regulated by the oil hydraulic pessure and working stroke of the cylinder 17. |
