| 摘要 |
PURPOSE:To execute cutting not having sticking of dross by adjusting pressure difference between first and second outlets of a separating device and maintaining purity of nitrogen rich gas, which is supplied as assist gas for a laser machining head, in the prescribed range while assist gas pressure changes. CONSTITUTION:For the purpose that a pressure of the nitrogen rich gas which is supplied to a laser chining head 9 depending on a laser machining condition, is corresponded to the machining condition, by operating a first pilot operated valve 25A, the setting of a first pressure regulating valve 15A is changed. At this time, because a differential pressure between a first conduit 11 and second conduit 13 is changed, the purity of nitrogen rich gas is changed. Accordingly, by operating a second pilot operated valve 25B so as to change the setting of a second pressure regulating valve 15B, a pressure difference between the first/second conduits is controlled. As a result, a purity of the nitrogen rich gas from a first outlet 1B of a first separating device 1 is maintained to the prescribed range (94-99.5%). |
