METHOD AND DEVICE FOR CONTROLLING LASER BEAM WELDING

PURPOSE:To detect the abnormality of a laser beam welding with an AE sensor and to enable the optimum control in the laser beam welding. CONSTITUTION:Sound generated at the time of executing the laser beam welding, is detected with an AE sensor 6 and the AE signal is compared with a reference data 10a. Then, in the case the actual AE signal is more than or less than the reference signal, this AE signal is compared with AE signal patterns 10b in various kinds of non-suitable welding conditions through a CPU 9. This AE signal pattern is the one stored by beforehand examining this pattern at the time of welding generated in the case of being the various kinds of the welding conditions, such as laser beam output, focus positioning of the laser beam, shield gas flow rate, assist gas flow rate, to out of the permissible range. In the case, the AE signal is similar with either one in the AE signal patterns, the welding condition corresponding to this pattern is corrected.