| 摘要 |
PROBLEM TO BE SOLVED: To suppress a welding state from being unstable when constriction detection control and feed speed variable control for making a welding current constant are both in operation during consumable electrode arc welding.SOLUTION: Constriction detection control to detect a constriction of a droplet as a precursor of regeneration of an arc from a short-circuit state and to generate an arc again after reducing a welding current once the constriction is detected is performed and a feed speed Fw is brought under variable control so that a welding current average value Iav becomes equal to a current set value. In the short-circuit state (Sd=High level), an operation of the feed speed variable control is inhibited and in an arc generation state, the feed speed variable control is performed. Consequently, even if a power supply chip-base material distance Lw varies, the feed speed Fw does not vary in the short-circuit state, so the welding state is prevented from being unstable as the constriction detection control is improperly performed. |
