| 摘要 |
PURPOSE:To prevent hunting of a shut-off valve in an unloaded during transition from a no load operation of a compressor into a full load operation or a volume control operation. CONSTITUTION:In a compressor body 1, pressure is fed into a control pressure chamber 38 in an unloaded 3 from a passage 22 so that the operating mode is shifted into a volume control operation mode when the pressure in a receiver tank 7 in which discharged compressed gas is reserved, exceeds a first set value, and the pressure in the receiver tank 7 reaching a third set value is detected by a pressure switch PS so that a change-over valve 26 is set to a position B at which the pressure in the passage 21 is fed into the control pressure chamber so that the mode is shifted into a no load operation mode. When the compressed gas in the receiver tank is consumed by a large quantity so that pressure becomes lower than the first set value, this pressure is detected by the pressure switch PS so that the change-over valve 26 is set to a position A while a solenoid valve 90 incorporating a timer is operated so that the gas under pressure is introduced a suction passage 12 or a secondary pressure chamber from the control pressure chamber 38 within a short time set by the timer. |
