To provide such a method and device for monitoring a weld zone in laser beam welding that are capable of sensing positional deviation from the abutting face of materials to be welded, by means of plasma light produced by laser beam welding.
A laser beam 2 irradiates the abutting part of a pair of materials 1 and 1 to be welded, and at the same time, the optical characteristics of the weld zone are detected by a sensor 3. If the luminous intensity detected by the sensor 3 is higher than the first reference value of a predetermined luminous intensity, it is judged the laser beam 2 is deviated from the abutting faces 4 and 4, and the aiming position of the welding with the laser beam 2 is controlled. On the other hand, if the luminous intensity detected is lower than the second reference value of a predetermined luminous intensity, it is judged there is a possibility of generating a weld defect in the weld zone.
ADACHI KAORU
MATSUMOTO TAIICHI
Next Patent: LASER CLAD WELDING METHOD