摘要:
A control valve is located in a variable displacement compressor incorporated in a refrigerant circuit. The control valve controls the displacement of the compressor in accordance with a pressure difference between a first pressure monitoring point and a second pressure monitoring point, which are located in the refrigerant circuit, such that the pressure difference seeks a predetermined target value. An adjusting valve, which is a variable throttle valve, is located in a section of the refrigerant circuit between the first and second pressure monitoring points. The adjusting valve adjusts the restriction amount of the refrigerant in relation to the refrigerant flow in the refrigerant circuit. The compressor displacement is thus optimally controlled.
摘要:
Compressor has a driving unit. The driving unit is provided within a crank chamber and decreases the discharge capacity when a control valve opens a control passage to increase the pressure within the crank chamber. The throttle passage delivers oil with the compressed refrigerant to the crank chamber regardless of whether the control valve has opened or closed the control passage. Because the throttle passage may continuously deliver the oil to the crank chamber even when the control valve closes the control passage, the mechanical elements within the crank chamber can be reliably and sufficiently lubricated and the crank chamber is prevented from being in an insufficiently lubricated state.
摘要:
An improved control apparatus for controlling the displacement of a variable displacement compressor. A control valve includes an operating rod, which is urged by a force based on a differential pressure between two pressure monitoring points, which are located in a refrigeration circuit. The control valve causes the compressor to seek a target displacement. A computer limits the target displacement when the demand for cooling is decreasing to improve fuel economy and to extend the life of the compressor.
摘要:
A control valve is located in a variable displacement compressor used in a refrigerant circuit. The control valve operates such that the pressure difference between two pressure monitoring points in the refrigerant circuit seeks a predetermined target value. A controller determines the target value of the pressure difference in accordance with external information that represents the required cooling performance. The target value of the pressure difference is represented by a duty ratio applied to the control valve. When the acceleration pedal is pressed beyond a predetermined level, the controller limits the duty ratio. Therefore, the compressor torque does not hinder quick vehicle acceleration. Also, the cooling performance is not lowered unless it is necessary.
摘要:
A controller controls a displacement of a compressor which is installed in a refrigerant circuit of an air-conditioning system. The controller has a pressure difference detector. An air conditioning switch turns the air conditioning system on. A temperature detector detects the temperature in a compartment. A control valve controls the displacement of the compressor such that the pressure difference detected by the pressure difference detector approaches a target value. A computer determines the target value. The computer changes the target value, depending on the detected temperature. The computer limits the target value to a target value limit. After a predetermined time expires from when the air conditioning switch is turned on, the computer changes the limit. This permits the displacement of the compressor to be promptly and reliably changed.
摘要:
A control valve is located in a variable displacement compressor that is installed in a refrigerant circuit. The control valve operates such that the pressure difference between first and second pressure monitoring points in the refrigerant circuit seeks a predetermined target value. The first pressure monitoring point is located in a discharge chamber of the compressor. The second pressure monitoring point is located in a flow pipe that extends from the discharge chamber. The static pressure of refrigerant in the discharge chamber is introduced into a control valve from the first pressure monitoring point. A pressure that includes the static pressure and the dynamic pressure of refrigerant in the flow pipe is introduced into the control valve from the second pressure monitoring point. As a result, the displacement of the compressor is reliably controlled without being affected by the thermal load of an evaporator.
摘要:
A valve body adjusts opening of a supply passage in response to the position in a valve chamber. A pressure-sensitive member is moved in accordance with the pressure difference between two pressure monitoring points, which are located in an external refrigerant circuit. The movement of the pressure-sensitive member affects the position of the valve body such that the compressor displacement is changed to reduce fluctuations in the pressure difference. A solenoid changes force applied to the valve body so that a set pressure difference, which is a reference value for changing the position of the valve body by the pressure-sensitive member, is changed.
摘要:
An engine control apparatus of a vehicle having an air conditioner that has a variable displacement compressor is disclosed. The pressure difference between two points in a refrigeration circuit is monitored. The pressure difference represents the compressor displacement. The compressor is controlled by a control valve. The control valve operates based on the pressure difference. A controller compares the temperature of the passenger compartment with a temperature setting. If they differ, the controller determines a target pressure difference for the control valve. The controller computes the compressor torque based on the target pressure difference signal. The controller determines a target engine torque based on the compressor torque and controls the engine based on the target engine torque.
摘要:
A displacement control valve for a compressor is provided. When current to a coil is stopped due to, for example, a broken wire, the control valve prevents the load acting on a variable displacement compressor from becoming excessive. A suction chamber is connected to a crank chamber by a control passage. A bellows actuates a valve body in accordance with the pressure in a suction chamber thereby regulating the opening size of the control passage. The compressor displacement is varied accordingly. A solenoid varies the attraction between a plunger and a fixed core in accordance with the level of current supplied to a coil thereby changing a target pressure. The bellows is actuated based on the target pressure. The solenoid increases the target pressure as the current to the coil is decreased. When the current to the coil is stopped, the solenoid maximizes the target pressure.
摘要:
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.