Patent ID: 8502114

Claim:
An AC pulse arc welding method for carrying out welding by alternately repeating a reversed polarity period and a straight polarity period, the reversed polarity period in which a reversed polarity current including a peak current and a base current is allowed to flow, and the straight polarity period in which a straight polarity current is allowed to flow, the method comprising: setting a wire feed rate; setting a polarity ratio that is a ratio of the straight polarity period to a total period of the reversed polarity period and the straight polarity period; setting an AC frequency of AC pulse welding from the set wire feed rate and the set polarity ratio; setting a straight polarity current value in the straight polarity period from the set polarity ratio and the set AC frequency; setting an amount of heat for melting a wire and making an arc length constant based on the set wire feed rate; calculating an appropriate current integral value that is an amount of heat necessary for one cycle of an electric current waveform of AC welding by dividing the amount of heat by the set AC frequency; calculating a current integral value necessary for the straight polarity period by subtracting a welding current integral value in the reversed polarity period from the appropriate current integral value; and determining the straight polarity current value from the straight polarity period and the current integral value necessary for the straight polarity period, wherein, welding by changing the AC frequency when the polarity ratio is changed without changing the wire feed rate, by changing a base current period in the reversed polarity period, when the polarity ratio is changed without changing the wire feed rate, the AC frequency and the straight polarity current value are changed, thereby carrying out welding.