| 摘要 |
PURPOSE:To shorten the piercing time and to improve operability in passing through a piercing hole on a work by a laser beam by detecting a pressure drop of assisting gas generated on the inside of a laser beam nozzle by a pressure sensor. CONSTITUTION:The assisting gas pressure drop generated at the time of passing through the piercing hole 31 by the laser beam LB on the work W positioned on a work table 11 is detected and a piercing hole passing through completion signal is outputted to an I/O unit 55. Further, the signal is transferred to a control unit 53 and an ON signal is given to a laser beam oscillator 3 from an NC device 57. In order to cut the work W by the laser beam LB, the sensor 49 for detecting the pressure is provided in the laser beam nozzle 27 provided at the lower part of a machining head assembly body 13 and the pressure sensor 49 is connected with the control unit 53 which is connected with the laser beam oscillator 3 by a signal cable 51 via the NC device 57. As a result, the change of frequency of the pressure in the laser beam nozzle 27 can be detected regardless of material and thickness of the work W. |
