Abstract: The laser welding device includes a laser transmission window and a gas injection nozzle. The gas injection nozzle includes an optical path hole and an injection unit that injects an inert gas for shielding metal vapor into the optical path hole toward an irradiation direction side and an optical axis side of a laser beam.

Abstract: A laser welding device includes a chamber which has an internal space in which a workpiece is disposed, a laser beam irradiation unit which irradiates the workpiece with a laser beam to weld the workpiece, a vacuum pump which suctions air in the chamber to decrease a pressure in the chamber, a laser transmission window through which the laser beam emitted from the laser beam irradiation unit is transmitted, and a shutter which is disposed on the chamber side with respect to the laser transmission window and closed when the pressure in the chamber is returned to the atmospheric pressure after laser welding.

Abstract: The laser welding device includes a laser transmission window and a gas injection nozzle. The gas injection nozzle includes an optical path hole and an injection unit that injects an inert gas for shielding metal vapor into the optical path hole toward an irradiation direction (E) side and an optical axis (A) side of a laser beam (L).

Abstract: A laser welding device includes a chamber which has an internal space in which a workpiece is disposed, a laser beam irradiation unit which irradiates the workpiece with a laser beam to weld the workpiece, a vacuum pump which suctions air in the chamber to decrease a pressure in the chamber, a laser transmission window through which the laser beam emitted from the laser beam irradiation unit is transmitted, and a shutter which is disposed on the chamber side with respect to the laser transmission window and closed when the pressure in the chamber is returned to the atmospheric pressure after laser welding.

Abstract: This laser welding device includes a tubular portion. The tubular portion includes a first tubular portion and a second tubular portion. The second tubular portion has a constant cross-sectional shape orthogonal to an irradiation direction along the irradiation direction E. The tubular portion has a predetermined length that is longer than a length of a chamber in the irradiation direction.