| 摘要 |
PURPOSE:To perform copying control of higher accuracy and stability with the characteristics of the arc per se by controlling the movement in the width direction and axial line direction of a torch in welding wherein the groove surfaces on both sides of a root incline in the width direction with respect to a wire. CONSTITUTION:A torch welding the joing groove of base metals 1 is moved in a welding advance direction and a width direction respectively by means of motors 8, 9 and is attached to and detached from the base metals. The welding current I of a wire 2 is detected with a detector 10, and an integrator 12 integrates this with time in accordance with oscillation periods. This is compared with a reference value in a comparator 14, and the motor 9 is so controlled that the integrator output attains a prescribed value. Oscillation period signals are applied to the integrator 12, whilist the change-over signal of every half period is applied to a change-over device 17, then the device 17 distributes the detected current output alternately and equally to integration periods 18, 19 at every half period with the oscillation center as a reference point. These integrated values are compared in a differential amplifier 20, and the motor 8 is so controlled that the output thereof is made zoro. |
