| 摘要 |
PURPOSE:To prevent penetration of a tungsten electrode and to obtain penetration bead welding having an exact start part, by automatically setting a welding torch by a control device, and stopping an automatic voltage adjusting device until a welding start state is completed. CONSTITUTION:A welding torch 3 is moved automatically upwards and downwards, and to the left and right by operation of an automatic torch control device 14 and is set to a prescribed position. Subsequently, a signal is sent to a welding wire feed control device 9 from a welding control device 13, and a distance l between the tip of a wire 5 fed from a nozzle 6 and the tip of a tungsten electrode 4 is set to a prescribed distance. Subsequently, a welding current starts to flow and welding is started. In this state, a welding power source 11 is controlled by a signal from the welding control device 13, and the welding current, which gradually increases precisely and linearly to some time point from the start time point and thereafter becomes a prescribed steady state current, is supplied between the TIG welding torch 3 and steel pipes 1a, 1b. |
