Abstract: In accordance with an AC pulse arc welding method, a periodic welding current is applied, that includes, for a pulse cycle, negative current in electrode negative polarity and positive current in electrode positive polarity. Then, a negative current rate is set by a negative current rate setting value, where the negative current rate represents the ratio of the negative current to the welding current for the pulse cycle. Then, a feeding speed of welding wire as a consumable electrode is set by a feeding speed setting value. The method further includes: setting an average of the welding current by a welding current setting value; and performing automatic calculation of the feeding speed setting value by using a predetermined conversion function based on input of the welding current setting value and the negative current rate setting value.

Abstract: An output control method is provided for a pulse arc welding in which a welding current flows for one pulse period consisting of a peak period with a flow of a peak current and a base period with a flow of a base current. External characteristics of a welding power source are preliminarily set by a slope Ks, a welding current reference value Is and a welding voltage reference value Vs. The absolute value va of the welding voltage and the absolute value ia of the welding current during welding are detected. The integration Svb=?(Ks×ia?Ks×Is+Vs?va) dt is calculated from a starting point of an n-th pulse period. The n-th pulse period is ended when the integration Svb becomes no smaller than zero during the base period. Then, the (n+1)-th pulse period is started.

Abstract: In accordance with an AC pulse arc welding method, a periodic welding current is applied, that includes, for a pulse cycle, negative current in electrode negative polarity and positive current in electrode positive polarity. Then, a negative current rate is set by a negative current rate setting value, where the negative current rate represents the ratio of the negative current to the welding current for the pulse cycle. Then, a feeding speed of welding wire as a consumable electrode is set by a feeding speed setting value. The method further includes: setting an average of the welding current by a welding current setting value; and performing automatic calculation of the feeding speed setting value by using a predetermined conversion function based on input of the welding current setting value and the negative current rate setting value.

Abstract: An output control method is provided for a pulse arc welding in which a welding current flows for one pulse period consisting of a peak period with a flow of a peak current and a base period with a flow of a base current. External characteristics of a welding power source are preliminarily set by a slope Ks, a welding current reference value Is and a welding voltage reference value Vs. The absolute value va of the welding voltage and the absolute value ia of the welding current during welding are detected. The integration Svb=?(Ks×ia?Ks×Is+Vs?va) dt is calculated from a starting point of an n-th pulse period. The n-th pulse period is ended when the integration Svb becomes no smaller than zero during the base period. Then, the (n+1)-th pulse period is started.

Abstract: In a method and an apparatus for controlling AC pulse arc welding executed by supplying a welding current flowing between a welding wire and an object to be welded with feeding the welding wire at a feeding speed corresponding to a predetermined feeding speed setting signal, a one-period process for supplying the welding current is repeatedly executed. The one-period process includes a first process during a peak time interval, a second process during a negative electrode time interval, and a third process during a base time interval. The one-period process further includes a fourth process during a switching current interval, inserted between the peak time interval and the negative electrode time interval, for supplying a welding current having a switching current for stopping growth of droplet which is smaller than a threshold current with a positive electrode polarity.

Abstract: In a method and an apparatus for controlling AC pulse arc welding executed by supplying a welding current flowing between a welding wire and an object to be welded with feeding the welding wire at a feeding speed corresponding to a predetermined feeding speed setting signal, a one-period process for supplying the welding current is repeatedly executed. The one-period process includes a first process during a peak time interval, a second process during a negative electrode time interval, and a third process during a base time interval. The one-period process further includes a fourth process during a switching current interval, inserted between the peak time interval and the negative electrode time interval, for supplying a welding current having a switching current for stopping growth of droplet which is smaller than a threshold current with a positive electrode polarity.