Arc welding control method and arc welding machine

An arc welding machine for welding a member to be welded by repeating alternately a short circuit period allowing a welding wire to short circuit with respect to the member to be welded and an arc period allowing arc recurrence and arc discharge, comprising:

• a welding current detect part for detecting a welding output current;
• a welding voltage detect part for detecting a welding output voltage;
• a short circuit arc judge part for judging whether a welding state is in the short circuit period or in the arc period;
• a setting part for setting at least one of the set values of a current and a voltage in the short circuit period and in the arc period and outputting the set value;
• an arc initial control part for inputting thereinto the respective outputs of the welding current detect part, the welding voltage detect part and the setting part, setting a welding output current at an arc recurrence initial time, and outputting the thus set welding output current;
• a drive part for inputting thereinto the output of the short circuit arc judge part, and controlling such inputs selectively according to the arc state;
• and
• a timer part for inputting thereinto the output of the short circuit arc judge part, timing a given time starting from arc occurrence, setting an arc initial control time, and outputting the arc initial control time to the drive part,
• wherein the arc initial control part controls a welding current to be steeply lowered just before the arc recurrence;
• and
• wherein the arc initial control part controls a welding current at an arc recurrence time in the arc initial control time set by the timer part and starting from the arc recurrence to be always higher than a peak current of the welding current in the short circuit period, a value of the welding current at the arc recurrence time being determined based on a value of the peak current in the short circuit period.

An arc welding control method for welding a member to be welded, comprising the steps of:

• repeating alternately a short circuit period allowing a welding wire to short circuit with respect to the member to be welded and an arc period allowing arc recurrence and arc discharge;
• and
• controlling a welding output current to have a peak current in the short circuit period;
• controlling a welding output current just after arc recurrence to be always higher than a welding output current just before arc recurrence for a set given period starting from arc recurrence,
• wherein a value of the welding output current just after arc recurrence is determined based on a value of the peak current in the short circuit period.

An arc welding machine for welding a member to be welded by repeating alternately a short circuit period allowing a welding wire to short circuit with respect to the member to be welded and an arc period allowing arc recurrence and arc discharge, comprising:

• a welding current detect part for detecting a welding output current;
• a welding voltage detect part for detecting a welding output voltage;
• a short circuit arc judge part for judging whether a welding state is in the short circuit period or in the arc period;
• a setting part for setting at least one of the set values of a current and a voltage in the short circuit period and in the arc period and outputting the set value;
• an arc initial control part for inputting thereinto the respective outputs of the welding current detect part, the welding voltage detect part and the setting part, setting a welding output current at an arc recurrence initial time, and outputting the thus set welding output current;
• a drive part for inputting thereinto the output of the short circuit arc judge part, and controlling such inputs selectively according to the arc state;
• and
• a timer part for inputting thereinto the output of the short circuit arc judge part, timing a given time starting from arc occurrence, setting an arc initial control time, and outputting the arc initial control time to the drive part,
• wherein the arc initial control part controls a welding current at an arc recurrence time for the arc initial control time period set by the timer part to be always higher than a welding current just before arc recurrence, wherein the arc initial control time period starts from arc recurrence;
• and
• wherein a value of the welding current at the arc recurrence time is determined based on a value of the peak current in the short circuit period.