| 摘要 |
PURPOSE:To prevent the deflection of the leading end of a butt weld zone by oscillating ultrasonic wave signals to said weld zone and regulating the irradiation of an electron beam in such a way as to maintain the deviation of both reflection signals from the leading end of the weld zone and the newly provided 2nd groove line with time at a constant value. CONSTITUTION:Other than the 1st groove line 4, the 2nd groove line 6 parallel with the line 4 is provided. A distance difference is detected from both ultrasonic reflection signals from the line 6 and the leading end 5a of the weld zone detected with a transducer 7, in a time difference operating circuit. Next, the irradiation of an electron beam 1 is automatically regulated in such a way that said difference attains the same value as a reference value. In this way, the welding is executed by following up the leading end of the weld zone at all time in the above-mentioned manner, the deflection of the leading end of the weld zone is prevented. |
