| 摘要 |
PURPOSE:To permit satisfactory time of inspection for the arc, and to make possible the improvement of the working efficiency without necessity of skill, by alternately driving to rotate two welding heads arranged in two weld points of the stationary pipe, around the axis of the stationary pipe. CONSTITUTION:The welding conditions, suitable for the stationary pipe 5 to be welded, from the first pass (the first layer) to the fourth pass (the final layer), are preset in four condition setting dials of the welding power source 1. Next, the welding head 2a is set to the pipe 5 and is started. The output switching circuit 10 is connected to the head 2a, the welding is started, and the welding is carried on along the periphery of the pipe 5 by the welding control circuit 8. When the head 2a makes one turn and the one pass welding is finished, the circuit 10 is actuated by the command of the automatic stepping circuit 9 for the welding motion, and the welding current is switched to the welding head 2b; thus, the welding is automatically carried on. At the same time, the head 2a returns to the starting point of welding by the control circuit 7 for reversing the head. This alternate motion is repeated and the multilayer welding for two points is carried out. The worker operates only the setting of the arc length. |
