LASER WELDING QUALITY EVALUATION DEVICE

PROBLEM TO BE SOLVED: To provide a laser welding quality evaluation device capable of extensively picking up an image of a molten pool without relying on the monitor light from the outside. SOLUTION: In the laser welding quality evaluation device to evaluate the welding quality from the image of the molten pool picked up by a CCD camera by taking in the reflected light of the welding laser beams A emitted from a laser torch 1 to a work, the skirt of the beam intensity distribution profile of the laser beams is expanded close to a rear end of the molten pool extending to the rear side of the welding direction by changing the shape of a convex lens 23 on the emission side of the laser beams A out of two convex lenses 21, 23 to constitute the optical system in the laser torch. The change of the shape of the convex lens 23 includes the content of obliquely cutting a circumferential edge on the side opposite to a convex surface 22 of the convex lens 23 as an example and forming the cut part to be a divergent part 24. COPYRIGHT: (C)2006,JPO&NCIPI