| 摘要 |
PURPOSE:To prevent the decrease in the long term reliability of a laser oscillator due to the mixture of oil mist in gas circulating system by controlling to exhaust gas in the gas circulating system from an oil tank of a circulating pump or from the gas circulating system at the leakage time. CONSTITUTION:A leakage valve 8 is closed by a sequence controller 11, the operation of an exhaust pump 6 is started, the valve 7 is opened, and gas in the system is evacuated. Since the gas is exhausted through an oil tank 35, it is not necessary to contaminate in the system with oil mist. A gas supply valve 9 is closed at the stopping time, and a circulating pump 3 is stopped. The valve 8 is opened, and the valve 7 is gradually closed, and the pump 6 is stopped. When the leakage valve 8 is opened, gas (air) is introduced into the system, but since the valve 9 is closed so as to maintain the state that the pressure in the oil tank 35 is lower than the gas pressure in the pump, oil mist in the tank 35 does not reversely flow into the gas circulating system. |
