| 摘要 |
PURPOSE:To obtain a titlted device that eliminates unstable welding at the time of starting of welding by generating an arc between the end of electrode of a welding torch and a filler wire before the filler wire arrives at the object to be welded, and preheating the filler wire by the heat of arc. CONSTITUTION:A DC power source 32 is set to make 0<E1-E2<E where E1 is voltage of the first DC power source 18, E2 is the second DC power source 32 before a filler wire 22 arives at an object 10 to be welded, and e2 is voltage of the second DC power source after the filler wire arrives at the object 10. Then, a high frequency generator 36 is operated to supply high frequency current to a coupling coil 34. High frequency current is let flow between the electrode terminal of a welding torch 12 and feeding terminal of a wire 22 to heat the wire 22. When the torch 12 is brought close to the object 10 to be welded, an arc is generated between the electrode 12a of the torch 12 and the object 10 to be welded, and welding current is let flow as output voltage of the power source 18 is high. At the point of time when the welding current flows, a driving roller is rotated and the wire 22 is fed to the weld zone. At the same time, output of the power source 32 is switched to voltage e2 to apply secified heating current basing on, for instance, a detection signal that detected flow of the welding current. |
