Laser welding defect detection device and defect detection method

摘要

PROBLEM TO BE SOLVED: To provide the device capable of stable defect detection. SOLUTION: In the housing of a laser torch 12, a condensing lens 15 is provided converging welding light produced from a welding part so as to be in the same optical axis as that of the laser beam emitted to a workpiece 14; the converged welding light is separated into two directions with a YAG light reflecting mirror 1 on which pin holes are provided; and, on the basis of the intensity of the two separated welding light beams, the defect detection is performed for a welding part.