| 摘要 |
PURPOSE:To provide the method and device capable of detecting the welding quality with uniform characteristics extending over the entire length of the weld zone by discriminating the welding quality of the weld zone by utilizing laser beam induced plasma. CONSTITUTION:An electrode 10 is arranged along the longitudinal direction of the weld zone directly under the laser beam weld zone of welding works 1, the potential difference between this electrode 10 and the welding works 1 is detected, a passing through state to the welding work 1 rear is detected based on this detected potential difference and the welding quality is discriminated. Even when a sensor for detecting the welding quality having uniform characteristic cannot be arranged on a part corresponding to the weld zone by setting a jig to hold the vicinity of the weld zone firmly in butt welding of steel sheets used for an automobile panel, etc., the passing through state to the welding work 1 rear can be detected with uniform characteristics extending over the entire length of the weld zone. |
