| 摘要 |
PURPOSE:To prevent the occurrence of the defect of seam disconnection by performing inside welding with the amount of travel of an outside welding torch as the profile reference of an inside welding torch. CONSTITUTION:When the seam B of a steel sheet formed spirally continuously is moved from the specified position, an operator observes the deviation between the seam and the outside welding torch 1 and operates the driving motor 2 of the outside welding torch 1 by a manual operation to correct the positional deviation. The amount of travel of the outside welding torch 1 at this time is measured by a detector 7 and based on the amount of travel, the positional feedback of the inside welding torch 3 is controlled by a controller 8. The amount of travel of the inside welding torch 3 is set in accordance with the travel of a regular formed steel pipe on the controller 8. When the outside welding torch 1 is moved, the amount of travel is inputted to the controller 8 and the travel in the amount adjusted by this input is carried out by a driving device 5. |
