PURPOSE: To change welding conditions with prompt feedback of a penetration state by moving a non-contact type ultrasonic porbe along the weld line direction and disposing the same right under the weld zone in a molten state.
CONSTITUTION: A traveling device 8 is moved in the weld line direction to move a welding torch 15 and a non-contact type probe 4 provided to a traveling base 7 in the weld line direction by means of a guide 10 erected on the base 7. The probe 4 in this stage moves while it is held in the position right under a weld zone 3 in a molten state. The quantity of the reflected echo by the probe 4 is outputted as an electrical signal through a flaw detector 5 to a central processing unit 16, and the signal indicating the desirable penetration state is outputted from the unit 16 to a display device 17 and a welding power source 18. Lack or excess of penetration is displayed as it is and the welding current is adequately controlled.
NONAKA TOSHIO
ARIMA YUKIO
OGURA YUKIO
MATSUMOTO YASUJI
KAMIYAMA YOUICHI
