Capacity Control Valve with CS-DC Valve Separation for Compression Efficiency
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Solution Overview
Problem
Existing capacity control valves for variable displacement compressors suffer from reduced compression efficiency due to continuous coolant flow through an auxiliary communication passage during continuous operation, affecting startup fluid discharge functionality.
Innovation Solution
A capacity control valve design featuring a CS valve and a DC valve, where the CS valve element and DC valve element move together to maintain a closed state, allowing for independent control of the DC valve while the CS valve is closed, enabling efficient fluid discharge and compression by adjusting control pressure through suction pressure supplementation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an auxiliary communication passage is always open to discharge fluid at startup, then startup fluid discharge functionality is improved, but compression efficiency deteriorates during continuous operation due to coolant leakage
Solution Approach 1:
The patent applies the dynamics principle by making the auxiliary communication passage dynamically controllable through a valve element. The passage is closed during normal operation to maintain compression efficiency and opened during startup to enable fluid discharge. The valve element moves between closed and open positions based on operational requirements, transforming a static always-open passage into a dynamically controlled flow path that adapts to different operational phases.
2Device complexity
If a single valve element controls both CS valve and DC valve, then device complexity is reduced, but control precision deteriorates because both valves cannot be independently controlled
Solution Approach 1:
The patent applies segmentation by dividing the single valve element into two separate valve elements: a first valve element for controlling the CS valve and a second valve element for controlling the DC valve. This segmentation allows independent control of each valve, enabling precise control of fluid flow paths. The first valve element responds to solenoid activation to control the auxiliary passage, while the second valve element responds to pressure differential to control the main discharge path.
Solution Approach 2:
The patent introduces a pressure differential as an intermediary mechanism that acts on the second valve element. The pressure differential between the control chamber and suction chamber serves as a mediator that automatically opens the DC valve when needed, eliminating the need for direct electromagnetic control while maintaining precise control functionality. This intermediary pressure-based control complements the electromagnetic control of the first valve element.
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
This design enhances startup fluid discharge functionality and maintains high compression efficiency by allowing communication between the control port and suction port while maintaining a closed DC valve state, reducing electric current consumption and improving responsiveness.
Implementation Method 1
a valve element is moved in the axial direction by electromagnetic force generated in a solenoid
Implementation Method 2
the pressure drive portion is driven by the suction pressure
Data Source
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AI summary
A capacity control valve with which a fluid discharge function at the time of start-up is excellent and compression efficiency is high is provided. The capacity control valve includes a valve housing 10, 12; a rod 83 configured to be driven by a solenoid 80; a CS valve 50 formed by a CS valve seat 53a and a CS valve element 51 and configured to open and close a communication between the control port 15 and the suction port 13; a DC valve 54 formed by a DC valve seat 10b and a DC valve element 53 and arranged movably with respect to the CS valve element 51, the DC valve 54 being configured to open and close a communication between the discharge port 14 and the control port 15 in accordance with a movement of the rod 83; and a pressure drive portion 61 coupled to the CS valve element 51 to be movable in an integrated manner with the CS valve element 51 and arranged in a suction fluid supply chamber 60 which is formed in the valve housing 10 and to which the suction fluid is supplied, the pressure drive portion 61 being driven by the suction pressure. The CS valve element 51 and DC valve element 53 are moved together by the movement of the rod 83 while maintaining a closed state of the CS valve 50. When the rod 83 is further moved, the CS valve element 51 is moved alone and the DC valve element 53 is left while maintaining a closed state of the DC valve 54.