Method of controlling wobble plate type compressor

Claim 1

A method of controlling the operation of a variable displacement wobble plate type compressor provided with: a cylinder block having formed therein, a plurality of cylinder bores to receive therein compressor pistons; a housing means arranged on axially opposite ends of the cylinder block for defining therein a suction chamber for a low pressure refrigerant gas to be compressed, a discharge chamber for a compressed high pressure refrigerant gas, and a crankcase chamber for receiving a pressure responsive displacement varying means including a drive shaft connectable to a rotative drive source means, a drive plate mounted around the drive shaft and capable of rotating with the drive shaft and varying an inclination angle thereof with respect to a plane vertical to the axis of the drive shaft and a wobble plate non-rotatably supported by the drive plate, the wobble plate inclining with the drive plate in response to a pressure difference between the crankcase chamber and the suction chamber, and connected to the compressor pistons via piston rods to cause a reciprocating motion of the compressor pistons with variable stroke to thereby vary the displacement of the compressor; a solenoid-operated control valve means arranged in a pressure control passageway means extending from the discharge chamber to the crankcase chamber for changing an extent of fluid communication between the crankcase and discharge chambers; and a control means for electrically controlling the operation of the solenoid-operated control valve, comprising the steps of: (a) generating a command signal for a rapid reduction in displacement of the compressor by said control means in response to a demand for a reduction of the displacement of the compressor; (b) responding to the command signal, supplying the solenoid-operated control valve with an electrical energizing signal having a predetermined intensity greater than the intensity required to maintain a predetermined reduced displacement of the compressor to increase the extent of fluid communication between the crankcase and discharge chamber during a predetermined initial part of a time period in which the demand for a reduction of the displacement of the compressor is required; and (c) reducing the electrical energizing signal supplied to the solenoid-operated control valve to the intensity required to maintain the predetermined reduced displacement of the compressor for the remaining part of the time period in which demand for the reduction of the displacement of the compressor continues.

Claim 2

A method of controlling the operation of a variable displacement wobble plate type compressor provided with: a cylinder block having formed therein, a plurality of cylinder bores to receive therein compressor pistons; a housing means arranged on axially opposite ends of the cylinder block for defining therein a suction chamber for a low pressure refrigerant gas to be compressed, a discharge chamber for a compressed high pressure refrigerant gas, and a crankcase chamber for receiving a pressure responsive displacement varying means including a drive shaft connectable to a rotative drive source means, a drive plate mounted around the drive shaft and capable of rotating with the drive shaft and varying an inclination angle thereof with respect to a plane vertical to the axis of the drive shaft and a wobble plate non-rotatably supported by the drive plate, the wobble plate inclining with the drive plate in response to a pressure difference between the crankcase chamber and the suction chamber, and connected to the compressor pistons via piston rods to cause a reciprocating motion of the compressor pistons with variable stroke to thereby vary the displacement of the compressor; a solenoid-operated control valve means arranged in a pressure control passageway means extending from the discharge chamber to the crankcase chamber for changing an extent of fluid communication between the crankcase and discharge chambers; and a control means for electrically controlling the operation of the solenoid-operated control valve, comprising the steps of: (a) generating a command signal for a rapid reduction in displacement of the compressor by said control means in response to a demand for a reduction of the displacement of the compressor; (b) responding to the command signal, supplying the solenoid-operated control valve with an electrical energizing signal having a predetermined intensity greater than the intensity required to maintain a predetermined reduced displacement of the compressor to increase the extent of fluid communication between the crankcase and discharge chamber during a predetermined initial part of a time period in which the demand for a reduction of the displacement of the compressor is required; and (c) reducing the electrical energizing signal supplied to the solenoid-operated control valve to the intensity required to maintain the predetermined reduced displacement of the compressor for the remaining part of the time period in which demand for the reduction of the displacement of the compressor continues.