| 摘要 |
PURPOSE:To detect a groove position without contact and to perform stable and exact copying control in the stage of welding a very small groove at a high speed by utilizing the arc characteristic of the arc from a non-consumable detecting electrode in precedence of a welding electrode. CONSTITUTION:A non-consumble detecting electrode DT which is movable upward and downward and is movable in the transverse direction of a groove is provided forward in the advancing direction of a welding electrode. The two electrodes are both advanced and current is conducted thereto from a constant current source. The electrode DT is woven in the transverse direction of the groove at a specified period while an arc is generated from the electrode DT. The constant arc length control of the electrode DT and the control for copying the groove by time integration and comparison of the detected value of the arc voltage are accomplished during this time. If there is no positional deviation at the center C of the electrode weaving from the position in the transverse direction of the groove, a peak is generated in the arc voltage Va of the electrode DT in the position C and the areas SL, SR of the arc voltage waveform on both right and left sides of the center C are approximately equal. When the center C deviates to, for example, the right side of the groove, the peak transfers to the left side, thus resulting in SL>SR and further SR=0. The electrode DT and the welding electrode are integrally moved to attain SL=SR. |
