Patent ID: 7273356

Claim:
A control valve device for a variable capacity type swash plate compressor for use in an air conditioning system, the compressor including a suction chamber of a refrigerant, a discharge chamber of the refrigerant, and a crank chamber in which a swash plate is accommodated, a tilt angle of the swash plate determining a discharge capacity of the compressor and being adjusted by a pressure in the crank chamber, the control valve device comprising: a refrigerant path permitting introduction and release of the refrigerant with respect to the crank chamber, and including an introducing passage connecting the discharge chamber to the crank chamber and a release passage connecting the crank chamber to the suction chamber; a control valve inserted in one of the introducing passage and the release passage to control the pressure in the crank chamber, said control valve including: a valve unit having a valve member for opening/closing said one passage and a valve spring for urging the valve member in an opening or closing direction of said one passage; and an electromagnetic solenoid assembly operating said valve unit, and including a magnetic circuit for generating an electromagnetic force of a direction reverse to that of the urging force of the valve spring when a current is supplied, and having a fixed core, and an operating rod slidably extending through the fixed core to transmit the electromagnetic force to the valve member; a resistance variable mechanism for varying a magnetic resistance of the magnetic circuit in accordance with a differential pressure of the refrigerant between two points defined in the air conditioning system; and control means for supplying a predetermined current to said electromagnetic solenoid assembly based on a target discharge capacity required for the compressor.