| 摘要 |
<p>PROBLEM TO BE SOLVED: To control a welding position by optically detecting an object to be welded, in butt welding by a laser beam. SOLUTION: A keyhole 4 or a molten pool 5 formed in a weld zone and a butt groove 2 are irradiated with an ultraviolet laser as a measuring laser beam, detecting an image consisting of wavelength components in the ultraviolet region containing the wavelength of the ultraviolet laser, determining from this image the position of the butt groove 2 and the keyhole 4 or the molten pool 5, and controlling the welding position. By the irradiation of the ultraviolet laser, not only the welding laser beam (infrared region) but also the reflected light from the weld zone (melting part), for which a visible ray region is the main body, and the reflected light of the ultraviolet laser beam are separated by a filter. In the reflected light beams, by detecting the components in the ultraviolet region, an image in the part irradiated with the welding laser beam and in its neighborhood can be directly obtained, enabling the welding position to be measured.</p> |
