arc welding equipment, constant-voltage characteristic welding power source and arc welding method

摘要

PROBLEM TO BE SOLVED: To increase the possibility of always keeping the ark length constant during carrying out upward welding while generating an arc in a bevel of a steel plate to be welded so as to form a molten pool.SOLUTION: A welding apparatus 1 includes a welding machine carrying out arc welding by generating an arc in a nearly vertical and downward direction from a welding wire in a bevel G of a base metal B, a raising motor 16 raising the welding machine relatively in a nearly vertical and upward direction with respect to the base metal B and a welding power source 30 supplying power to the welding wire to generate the arc. A speed adjustment circuit 50 controls the raising motor 16 in such a way as to decrease the rising speed of the welding machine when the current value of the welding power source 30 is smaller than a set current value and increase the rising speed of the welding machine when the current value of the welding power source 30 is greater than the set current value. A voltage adjustment circuit 60 controls the welding power source 30 in such a way as to increase the voltage when the number of times of the voltage value of the welding power source 30 on welding being lower than a determination voltage is greater than a set number of times or when the time in which the voltage value of the welding power source 30 on welding being lower than the determination voltage is longer than a set time and to decrease the voltage when the number of times or the time is smaller or shorter.