| 摘要 |
PROBLEM TO BE SOLVED: To provide an air compressor performing opening and closing operation of a purge valve at the optimal timing, even when changing the pressure setting of compressed air supplied to the consumption side. SOLUTION: This air compressor includes a capacity control device, and can purge the compressed air in a discharge flow passage by opening the purge valve, by communicating the purge valve 11 with the discharge flow passage 21 being the primary side of a check valve 6 arranged in a flow passage reaching the consumption side from a compressor body 2. When a sensor 51 detects that secondary side pressure of a suction valve 31 becomes predetermined purge starting pressure lower than atmospheric pressure by blocking-up of the suction valve 31 arranged in a suction port of the compressor body, or lower, the pressure in the discharge flow passage is reduced by opening the purge valve, and after opening the purge valve, pressure in a consumption flow passage is continuously measured by a sensor 52, and when the measured pressure becomes pressure lower by a predetermined preset value than the pressure in the consumption flow passage when opening the purge valve 11, or lower, the purge valve is closed. COPYRIGHT: (C)2011,JPO&INPIT
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