METHOD AND DEVICE FOR DETECTING MACHINING DEFECT FOR LASER BEAM MACHINING DEVICE

摘要

PROBLEM TO BE SOLVED: To surely detect a machining defect of a work and to protect such optical parts as mirrors arranged in a machining head without making an optical system sophisticated and expensive. SOLUTION: In a laser beam machining device where an oscillation output of a laser oscillator is controlled by feeding an output of laser beam monitoring device 30 which monitors the output of a laser beam outputted from the laser oscillator on the basis of an output command signal back to the output command signal, a response characteristic similar to that which predicts a response characteristic of the laser beam monitoring means 30 is given to an output command signal monitoring means 50 which monitors an output command signal prior to the feed back of the output of the laser beam monitoring means 30. Further, an alarm is generated when the output of the laser beam monitoring means 30 exceeds an incremented output which is the output of the output signal command monitoring means 50 incremented by a predetermined value.