A welding condition corresponding to the hit point to be worked is retrieved from a welding condition data base 73, a starting signal for welding is outputted to a welding timer 77, and a pressurizing signal is outputted to an electric-pneumatic proportional valve 79 by a welding condition changing part 75 to which the information of hit point to be worked is inputted, and the welding work is performed. この作業打点情報の入力を受ける溶接条件変更部75は、その作業打点に対応した溶接条件を、溶接条件データベース73から検索し、溶接起動信号を溶接タイマ77に出力するとともに、加圧力信号を電空比例弁79に出力して溶接作業を行う。 - 特許庁