| 摘要 |
PURPOSE:To manufacture a weld joint being stable uniformly and free from a welding defect by measuring plate thickness, a step difference and misalignment, etc., of a material to be welded along a welding line, positioning focus of a laser beam in accordance with the result of this measurement and executing welding. CONSTITUTION:At the time of executing welding by butting a laser torch 3 in the plate transverse direction, that is, in the welding direction and moving it along a groove line, distances l1, l2 to the surfaces of each metallic belt, 1, 2 in the vicinity of a butting groove from the laser torch 3 or the reference surface T of the laser torch 3 are measured separately, and also, extending over the butting groove, that is, the overall length of a welding line. Subsequently, based on these measured distances l1, l2, nominal plate thickness given in advance or measured plate thickness measured in advance, and a distance extending from the laser torch 3 to a metallic belt bus line, the step difference quantity of the butting faces of both the metallic belts 1, 2 is derived, and an optimum focal position is derived therefrom. Next, based on the difference of this optimum focal position and a laser beam focus, the laser torch 3 is moved so that the laser beam focus is concentrated in the optimum focal position, and welding is executed. |
