| 摘要 |
PROBLEM TO BE SOLVED: To reduce the occurrence of spatter caused by vibration of a molten pool, in a constriction detection time current control method for quickly reducing a welding current by detecting constriction of a droplet in a short-circuit period.SOLUTION: When detecting the constriction of the droplet, a welding current Iw energized to a short-circuit load is reduced, and is maintained at a low constriction current value Im, and when an arc is regenerated, the welding current Iw is raised up to a high arc current value Ih from the low constriction current value Im by imparting an inclination S to the welding current Iw when a delay period Td passes. This inclination S in a front half part and a rear half par is a value different from in an intermediate part, and is set so that the inclination of the front half part and the rear half part is a value smaller than the inclination of the intermediate part. Thus, transfer to an inclination period Tu from the constriction current Im and transfer to the high arc current Ih from the inclination period Tu become smooth, and the molten pool is not vibrated when arc force is suddenly changed, so that the occurrence of spatter can be reduced. |
