| 摘要 |
PURPOSE:To detect a weld line without contact by discriminating a shift of the right and left of a welding torch from a characteristic of a current differential value obtained by differentiating a welding current in the weaving center. CONSTITUTION:A titled device is constituted of a detecting part 25 for detecting a welding current flowing to a welding torch 11, a position detector 21 for detecting a weaving position of the welding torch 11, a differentiating circuit part 26 for deriving the polarity of a current differential value by differentiating the welding current detected by the detecting part 25 in the weaving center shown by a position signal from the position detector 21, a polarity storage part 27 for storing temporarily the polarity of each current differential value, a logical discriminating part 28 for discriminating that the welding torch 11 is shifted to the right if the polarity of - is obtaind first and subsequently the polarity of + is obtained, and discriminating that on the contrary, the welding torch 11 is shifted to the left if the polarity of + is obtained first and subsequently the polarity of - is otained, and an instructing part 29 for sending a shift correcting signal to a driving source 6 for moving the welding torch 11 in accordance with a discriminating signal. |
