METHOD AND DEVICE FOR PULSED ARC WELDING

摘要

PURPOSE:To perform stable welding in a wide current region with a stabilized arc length by performing pulsed arc welding using an electrode held at a constant speed at a constant current characteristic and controlling the frequency or duration time of pulse current while an average welding current value is at a critical current value or below. CONSTITUTION:Welding current is supplied from a base current control circuit 12 and a pulse current control circuit 11 through a tip T to a wire E. An arc length is stabilized by the self-control effect of the arc length occurring in a constant current characteristic if said current is at the critical current value determined by a welding condition or above. A switch SW is turned on by the current difference Ir-Io from a set circuit 17 for the critical current value if said current is at the critical value or below. The voltage difference Vr-Vo from a set circuit 13 for the welding voltage is applied as a signal to a pulse current control circuit 11, which controls the frequency or duration time of the pulse current thereby stabilizing the arc length. Since stable welding is performed in a wide current region, the above-mentioned method is economical.