OUTPUT CONTROLLING METHOD IN PULSE ARC WELDING

PROBLEM TO BE SOLVED: To improve transient response in pulse arc welding in which arc length is controlled by varying peak current and base current. SOLUTION: At the start of an n-th pulse period, peak current set value Ipr and base current set value Ibr are calculated based on an error between welding voltage set value and welding voltage processed value. A reference peak period Tps, a reference base period Tbs and a reference pulse period Ts are preliminarily set to calculate target welding current average value Iar=(Ipr×Tps+Ibr×Tbs)/Ts. Peak current is made to flow by limiting the peak current set value Ipr in the range of the peak current upper limit value Ipu and the peak current lower limit value Ipd, while base current is made to flow by limiting the base current set value Ibr in the range of the base current upper limit value Ibu and the base current lower limit value Ibd. Thus, a peak period and a base period are made to vary so that the welding current average value in the n-th pulse period is equal to the target welding current average value Iar. COPYRIGHT: (C)2011,JPO&INPIT