| 摘要 |
<p>PROBLEM TO BE SOLVED: To correctly control the irradiation position of the laser beam so that the laser beam constantly irradiates the center line of a groove, and to prevent the effect of the spatter, etc. to be generated during the welding in achieving the butt welding of a base metal to be welded with the laser beam. SOLUTION: A groove 4 and a part near a key hole 7 are simultaneously photographed by an imaging means during the butt welding with the laser beam, the obtained brightness of the pixels of each image of the groove 4 and the part near the key hole 7 is detected in the direction orthogonal to the welding direction, respective brightness distribution curves for the groove 4 and the key hole 7 are prepared, the center positions of the brightness distribution width of the change point in the respective brightness distribution curves for the groove 4 and the key hole 7 is obtained, and the irradiation position of the laser beam is controlled so that the center positions are coincident with each other.</p> |
