| 摘要 |
PURPOSE:To raise a profiling accuracy of a weld line by rotating the first and the second magnetic sensors so that output signals of the first and the second distance detecting devices become equal, respectively. CONSTITUTION:When welding is executed, a thermal distortion is generated in an object 5 to be welded, and the first distance detecting device 11a and the object 5 to be welded approach each other. A difference of output signals of the first and the second distance detecting devices 11a, 11b is amplified by a differential amplifier, sent to a rotary device 20, and it rotates in the direction in which the output signals of the detecting devices become equal to each other. Accordingly, it is placed opposingly in parallel to the object 5 to be welded. Subsequently, a distance control device 12 operates so that the output signal of the first distance detecting device 11a and initial set value stored in advance in the distance control device 12 become equal. In the end, a weld line gap is specified by adding or subtracting a shift to or from the maximum position of a leakage magnetic flux detected by the first and the second sensors 6a, 6b, and based on its position information, welding is executed. |
