| 摘要 |
PURPOSE:To economize motive power and prevent freezing of an evaporator and seizure of a compressor by providing a compressor with variable capacity and reducing the amount of the medium inhaled into a compressor in high-speed revolution of an engine and controlling the compressor by the discharge pressure and the intake pressure. CONSTITUTION:If the back pressure of an ON/OFF valve 20a is switched to intake pressure (low pressure) by operating a three-way valve 26a through electromagnetic operation etc. when an engine is revolved in high speed or the freezing load is reduced, the differential presure of the ON/OFF valve 20a reduces nearly to zero, and the valve 20a is pushed-up by a spring 21a, and a subintake opening 12a is opened to communicate to a bypass groove 7b through a communication passage 13a. As a result, suction stroke is formed until the vane 3b passes through the subintake opening 12a, and the compression volume in the operation chamber of a pump is reduced, while reducing the volume of the inhaled medium. Thus, the amount of the inhaled medium is reduced according to the necessary freezing load, the motive power can be economized, and freezing of an evaporator and seizure of the compressor can be prevented. |
