| 摘要 |
PURPOSE:To regulate a torch automatically to equalize weak current at the ends and form a recessed penetration bead free from defect by moving a torch repeatedly to left and right in the direction of width in a groove, and applying welding current at the center of movement and applying weak current outside of the center. CONSTITUTION:A torch 12 is moved to left and right repeatedly by a servo motor 22 of a slide unit 20 within a specified width in the groove of an object 10 to be welded. Welding current is let flow to the torch at the center of movement by a current controlling mechanism of the body 30 of a welding device and weak arc current that does not melt the base metal is let flow outside of the center of movement. At this time, arc voltages Va, Vb of left and right ends 12a, 12b of movement of the torch 12 are detected by a detector 24. The voltage difference Va-Vb is calculated by a comparator circuit 26, and amplified by an amplifier 28, and a servo motor 22 is operated to bring the center of movement of the torch 12 always to the center of groove 10a of the object 10 to be welded. |
