Control valve and method for controlling an air-conditioning system
AssigneeKabushiki Kaisha Toyoda Jidoshokki Seisakusho
InventorsMasaki Ota, Masahiro Kawaguchi, Ken Suitou, Ryo Matsubara, Taku Adaniya
Life of this patent
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Abstract
An air-conditioning system has a refrigerant circuit. The circuit includes a condenser, a expansion valve, an evaporator and a variable displacement compressor. The system has a pressure difference detector. The pressure difference detector detects the pressure difference between two pressure monitoring points located on the refrigerant circuit. A control valve and a controller control the displacement of the compressor in accordance with the pressure difference detected by the pressure difference detector. This permits the displacement of the compressor to be quickly changed.
Claims31
An air-conditioning system having a refrigerant circuit, wherein the circuit includes a condenser, a decompression device, an evaporator and a variable displacement compressor, the system comprising:
- a pressure difference detector for detecting the pressure difference between two pressure monitoring points located on the refrigerant circuit;
- and
- displacement control means, which controls the displacement of the compressor such that the flow rate of the refrigerant in the refrigerant circuit, which is estimated based on the detected pressure difference, seeks a predetermined value.
The air-conditioning system according to 16, wherein, when restoring the displacement of the compressor to the displacement that was produced immediately before the specific displacement control was started, the means for controlling the displacement continuously changes the displacement.
A method for controlling the displacement of a variable displacement compressor in a refrigerant circuit of a vehicle air-conditioning system, the method comprising:
- selecting a control mode from a plurality of modes including a normal displacement control mode and a specific displacement control mode;
- changing the displacement of the compressor such that the pressure difference between two pressure monitoring points, which are located in the refrigerant circuit, approaches a target pressure difference that reflects the temperature of a passenger compartment when the normal displacement control mode is selected;
- and
- controlling the compressor to have a predetermined displacement when the specific displacement control is selected.
A control valve used for a variable displacement compressor, wherein the compressor is a part of a refrigerant circuit, and wherein the compressor includes a crank chamber, a drive plate accommodated in the crank chamber, a supply passage for connecting a discharge pressure zone to the crank chamber, and a bleed passage for connecting a suction pressure zone to the crank chamber, wherein the inclination angle of the drive plate varies in accordance with the pressure in the crank chamber thereby controlling the displacement of the compressor, the control valve comprising:
- a valve housing;
- a valve chamber defined in the valve housing to form part of the supply passage or the bleed passage;
- a movable valve body located in the valve chamber to adjust opening size of the supply passage or the bleed passage;
- a pressure difference detector for detecting the pressure difference between two pressure monitoring points located in the refrigerant circuit, wherein the position of the valve body is affected by a force produced by the detected pressure difference;
- and
- an actuator for applying a force to the pressure difference detector, wherein the actuator changes a target pressure difference according to the external command.
Dependencies are inferred from the claim text.