| 摘要 |
PURPOSE:To prevent the generation of noises peculiar to a rotary compressor and to improve the unloader characteristics, by providing a relief valve designed to close when pressure in a pressure tank becomes lower than a predetermined value, at a part of a negative-pressure decreasing piping. CONSTITUTION:In releasing the pressure in a pressure tank 6 to the atmosphere by fully closing an intake throttle valve 2 under the state that no load is acted to an oil separator 6, the relief valve 14 is opened if pressure in the pressure tank 6 is higher than a set pressure of the relief valve 14. Therefore, pressure in the pressure tank 6 is supplied partially to a compressor inlet pipe 3 via a blow- off pipe 11 and a negative-pressure decreasing pipe 12, so that the negative pressure at the inlet of the compressor is decreased. On the orher hand, when pressure in the pressure tank 6 becomes lower than the set pressure of the relief valve 14, the valve 14 is closed. |
