| 摘要 |
PURPOSE:To make adaptation to narrow gap welding of single layer two passes possible in a groove copying method of an automatic welding device by controlling a torch of which the moving time is controlled constant with a timer in such a way as to copy one wall of the groove with good accuracy. CONSTITUTION:When the arc 14 moved along a groove line is at the point P0, a sliding part 6 is moved in a direction A by a motor 7, and approaches to a groove wall surface 20 from the inclined direction, then the arc length shortens and the arc voltage drops. This is detected with a voltage detector 13, and is compared with th reference voltage from a generator 15 in a comparator 16. When these coincide, the part 6 is moved in a direction B by means of a motor 7 with a polarity selector 18. At the same time, the operation of a timer 17 is started, and the position of the arc 14 upon lapse of a constant time from the turn-back point P1 is the point P2, and the arc 14 and the wire 12 come to positions 14', 12', respectively. This point P2 is set as the turn-back point apart from the wall surface 20 and the part 6 is moved in the direction A by the timer 17. |
