QUANTITY CONTROL DEVICE FOR COMPRESSOR

摘要

PROBLEM TO BE SOLVED: To restrict occurrence of impact sound generated by impact between a valve body and a valve seat along with a valve closing operation of a quantity control valve while preventing occurrence of over-shoot and increase of a consumption power.SOLUTION: An introduction flow passage 81 for introducing a discharging side pressure of a compressor main body 40 as a working pressure into a pressure receiving chamber 37 of a quantity control valve 10 is divided at a secondary side of a purge valve 80, one flow passage is formed as an air discharging flow passage 81c and the other flow passage is formed as a control flow passage 81b communicated with the pressure receiving chamber 37 of the quantity control valve 10. Orifices 72, 74 are arranged at this control flow passage 81b and a releasing flow passage 71, a flow rate of compressed gas passing through the pressure receiving chamber 37 is reduced while a pressure increasing speed in the pressure receiving chamber 37 is being kept to reduce the aforesaid impact sound generated when the quantity control valve 10 is closed and at the same time a required amount of discharging gas is assured by the discharging flow passage 81c, and after the operation is transferred to unload operation, a fast intake control and a releasing of discharging side pressure of the compressor main body 40 at a primary side of a check valve 44 are carried out.