Capacity control valve
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Solution Overview
Problem
The existing capacity control valve for variable displacement compressors experiences deteriorated compression efficiency due to refrigerant flow from the control port into the suction port through an auxiliary communication passage during continuous driving, affecting fluid discharge function.
Innovation Solution
A capacity control valve design featuring a main valve and a CS valve that move together to open communication between the control and suction ports, allowing control pressure to be lowered, along with an opening and closing valve that connects the control fluid supply chamber to the suction port, ensuring stable fluid discharge and high compression efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an auxiliary communication passage is always in communication to discharge control fluid during startup, then the fluid discharge function during startup is improved, but the compression efficiency deteriorates during continuous driving due to refrigerant flow from control port to suction port
Solution Approach 1:
The patent applies the dynamics principle by making the auxiliary communication passage dynamically controllable rather than always open. A CS valve is introduced to selectively open or close the auxiliary communication passage between the control port and suction port based on operating conditions. During startup, the CS valve opens to enable rapid pressure reduction and improve responsiveness. During continuous driving, the CS valve closes to prevent refrigerant leakage and maintain compression efficiency. This dynamic control resolves the contradiction between startup performance and continuous operation efficiency.
2Speed
If the auxiliary communication passage is opened to quickly lower control chamber pressure during startup, then the responsiveness of the variable displacement compressor is improved, but refrigerant flows from control port into suction port during continuous driving causing compression efficiency deterioration
Solution Approach 1:
The patent introduces a CS valve as an intermediary component that mediates the communication between the control port and suction port. This intermediary element allows selective control of the auxiliary communication passage, enabling rapid pressure reduction during startup while preventing harmful refrigerant flow during continuous driving. The CS valve acts as a gatekeeper that permits beneficial flow at startup and blocks harmful flow during normal operation, thus resolving the contradiction between responsiveness and compression efficiency.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The design enhances fluid discharge function during startup and maintains high compression efficiency by controlling the communication between control and suction ports, preventing refrigerant flow and optimizing pressure management.
Implementation Method 1
a rod driven by a solenoid; a main valve that includes a main valve seat and a main valve body to open and close a communication between the discharge port and the control port in accordance with a movement of the rod
Data Source
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AI summary
There is provided a capacity control valve having a good fluid discharge function during startup and a high compression efficiency. A capacity control valve V includes: a valve housing 10 and 11 provided with a discharge port 12, a suction port 13 and a control port 14; a rod 83 driven by a solenoid 80; a main valve 50 that includes a main valve seat 53a and a main valve body 51 to open and close a communication between the discharge port 12 and the control port 14 in accordance with a movement of the rod 83 moves; an opening and closing valve 54 including an opening and closing valve seat 52a and an opening and closing valve body 61 biased in a valve closing direction, the opening and closing valve 54 being configured to open and close a CS communication passage 57 communicating with the suction port 13 and a control fluid supply chamber 60 formed in the valve housing, the control fluid being supplied to the control fluid supply chamber 60; and a CS valve 56 that includes a CS valve seat 11a and a CS valve body 53 to open and close a communication between the control port 14 and the suction port 13, the CS valve body 53 being disposed so as to be movable relative to the main valve body 51, wherein the main valve body 51 and the CS valve body 53 move together as the rod 83 moves in a closed state of the main valve 50.