LASER WELDING DEVICE AND LASER WELDING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a laser welding device which can suppress a variation in a cross section shape of a bead.SOLUTION: This laser welding device 1 which welds a weld part 35 by radiating a laser beam 21 thereto comprises: shield gas supply means 15 which supplies a shield gas to the weld part 35; gas supply amount control means 14 which controls a flow rate of the shield gas; light intensity measurement means 12 which measures the light intensity of plasma light 22 radiated from the weld part 35; change rate calculation means 13 which calculates a change rate of the light intensity which is measured by the light intensity measurement means 12. Then, the gas supply amount control means 14 controls the flow rate of the shield gas which is supplied to the weld part 35 according to the change rate of the calculated light intensity.SELECTED DRAWING: Figure 1