PURPOSE: To perform satisfactory welding at a stable arc length without bead disturbance and spatters in consumable multi-electrode gas shielded arc welding by setting the distance between arc generating points at a specific value or below and impressing pulse current to at least one electrodes.
CONSTITUTION: The deviation ΔV of a target voltage Vm for at least one electrode 1 of multi-electrodes 1, 2 is detected by a voltmeter 4 and a pulse current control circuit 6 is thereby operated to maintain the pulse current 5 of the electrode 1 at a target average current value Im. The value Im, expressed by the specific equation, stabilizes the arc length without the mutual interference of the arcs even if the distance A between the arc generating points is made ≤25mm. The high-speed welding is thus executed without bead disturbance and spatters.
NAKANISHI MUTSUO
ASAI HIROSHI
