CONTROL DEVICE FOR VARIABLE CAPACITY COMPRESSOR

摘要

A control device for a variable capacity compressor is constructed such that a discharge capacity is decreased as the pressure in a crank chamber (24) increases and the discharge capacity is increased as the pressure in the crank chamber (24) decreases. The control device has an air delivery passage (40) penetrating between a discharge chamber (27) and a crank chamber (24), and an air-bleeding passage (41) penetrating between the crank chamber (24) and a suction chamber (26). The pressure in the crank chamber (24) is regulated through the air delivery passage (40) and the air-bleeding passage (41). A differential pressure valve (44) is provided in the control device. The valve causes the crank chamber (24) and the suction chamber (26) to be connected when the pressure difference between the discharge chamber (27) and a region (suction chamber (26) or crank chamber (24)) other than the discharge chamber is equal to or less than a predetermined value. The control device increases the efficiency of a compressor so as to satisfy the needs of power saving, and can be used for a clutch-less variable capacity compressor. Further, excellent start-up capability of a compressor is achieved.