| 摘要 |
PURPOSE:To improve a welding quality and a welding speed, and to extend a life of a laser oscillator by making a back shield gas flow to a groove opened to the surface of a base opposed to a welding position of an object to be welded. CONSTITUTION:A laser beam 1a is irradiated diagonally to an object to be welded 3, and a return to a laser oscillator is reduced. Also, a shield gas 8 is made to flow to a weld zone from a nozzle 6, and simultaneously, a back shield gas 9 is made to flow to the inside of a groove 5, too, of a base 4 of the rear side, and a back shield gas pressure is adjusted so as to be balanced with a gas pressure of the surface side and gravity, etc. working on a molten metal. In this way, a sound welding quality which is free from dropping of the molten metal and a welding defect such as an expanse of a gap of both members, etc., and a high welding speed are obtained. |
