| 摘要 |
PURPOSE:To detect a weld line easily without degrading workability by detecting the rate of displacement from the weld line by the detection signal from a magnetic field sensor which detects the leaking magnetic field generated by welding current. CONSTITUTION:A magnetic field detector 32 is oscillated at a specified amplitude in a y-axis direction with respect to a shielding gas nozzle 30 of a torch by a freely rotatable coupler 33. When a torch 30 is advanced in the direction of the straight line connecting the center of the amplitude and the nozzle 30 and if the center of the amplitude advances on the same weld line together with a wire electrode 31, the detection signal for the leaking magnetic field from the detector 32 is the pulse signal of a specified interval. When the electrode 31, hence the detector 32 deviate from the weld line 7 on advancing of the torch 30, the interval of the pulse signal changes. If the width of the deviation exceeds the amplitude of the detector 32, the pulse signal is no more produced. |
