METHOD AND DEVICE FOR EVALUATING QUALITY OF LASER BEAM WELDING

PROBLEM TO BE SOLVED: To surely recognize the situation of the generation of blow out from image picking-up picture. SOLUTION: A CCD camera 8 for receiving the reflected light B of a laser beam A which is reflected from a laser beam irradiation area through an optical filter 7 is fixed to a laser beam torch 1 for irradiating a material W to be welded with the laser beam and the image of a molten pool 5 including a key hole 4 and its periphery are picked up by the CCD camera 8. The picked-up image is sent to an image analyzing means 11 in a signal processor 9 and the positional variation of a back high luminance part which is located on the backside in the welding direction is calculated. Thereupon, arithmetic results (fluctuating frequency, the range of fluctuation, etc.) obtained by the image analyzing means 11 are compared with a preliminarily stored threshold value by the quality judging means 12 and it is judged that the blow out is generated in the case the arithmetic results exceed the threshold value. COPYRIGHT: (C)2006,JPO&NCIPI