Capacity Control Valve Spool Mechanism for Rapid Compressor Startup
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Solution Overview
Problem
Existing capacity control valves struggle to quickly reduce pressure in the control chamber of a variable-capacity compressor during startup, as the pressure sensitive body expands and closes the relief valve before the control pressure is reduced to a level similar to that during continuous operation, preventing further fluid discharge from the control chamber to the suction chamber.
Innovation Solution
The capacity control valve features a spool valve that maintains the second flow channel at a minimum opening area, allowing high-pressure fluid from the control chamber to be discharged to the suction chamber through the second flow channel, with the spool valve body moving to increase the opening of the second flow channel, and the main valve being seated on the main valve seat by the solenoid's driving force to close the main valve, ensuring quick pressure reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the pressure sensitive body is used to control the relief valve opening/closing, then the valve structure is simple and reliable, but the control pressure cannot be quickly reduced to the level during continuous drive because the relief valve closes before pressure reduction is complete
Solution Approach 1:
The invention divides the pressure reduction function into two separate pathways: a first flow channel with a relief valve for initial rapid pressure reduction, and a second flow channel with a spool valve for continuous pressure control. This segmentation allows each valve to operate in its optimal range - the relief valve provides fast initial reduction while the spool valve maintains precise control, resolving the contradiction between reliability and speed.
Solution Approach 2:
The invention introduces a spool valve that can dynamically adjust the opening area of the second flow channel based on control pressure levels. When the relief valve closes, the spool valve continues to open the second flow channel to maintain pressure reduction, creating a dynamic transition that ensures continuous pressure control without abrupt interruptions.
2Speed
If the solenoid drives the main valve to close quickly, then the startup response is fast, but the fluid discharge flow rate control precision decreases
Solution Approach 1:
The invention separates the valve functions into a main valve for rapid opening/closing operations and a spool valve for precise flow control. The main valve handles the binary open/close action required for startup response, while the spool valve's adjustable opening area provides continuous flow rate control, resolving the contradiction between speed and precision.
Solution Approach 2:
The spool valve acts as an intermediary between the solenoid's binary control signal and the continuous fluid flow. By adjusting the opening area of the second flow channel, the spool valve translates the solenoid's on/off state into variable flow rates, maintaining precision control while responding quickly to startup commands.
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 configuration allows for rapid pressure reduction in the control chamber at startup, enabling efficient fluid discharge and maintaining precise control over fluid flow rates, thereby addressing the limitations of existing valves.
Implementation Method 1
a solenoid that applies a driving force to the main valve body to close the main valve
Implementation Method 2
a pressure sensitive body that is disposed in the third valve chamber, applies a biasing force to the first valve part in the opening direction of a main valve by the expansion thereof, and contracts with an increase in the suction pressure Ps serving as surrounding pressure
Data Source
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AI summary
There is provided a capacity control valve that can quickly reduce pressure in a control chamber at the time of the startup of a variable-capacity compressor. A capacity control valve V includes a valve housing 10 having a main valve seat portion formed on an inner peripheral surface thereof, a main valve body 53 that has a main valve portion 53a capable of seating on the main valve seat portion 12c and is capble of blocking communication between a discharge port 12a and a control port 14a depending on a driving force of a solenoid 80, a relief valve 59 that is opened by pressure, a first flow channel 56 that allows the control port 14a and a suction port 13a to communicate with each other in a case where the relief valve 59 is opened, a second flow channel 90 that is formed at least partially in parallel with the first flow channel and allows the control port 14a and the suction port 13a to communicate with each other, and a spool valve body 52 that is reciprocatably disposed in a sleeve 83s and capable of adjustingan opening of the second flow channel 90 depending on the driving force of the solenoid. After the main valve portion 53a is seated on the main valve seat portion 12c, the spool valve body 52 is further moved by the driving force of the solenoid 80 and increases the opening of the second flow channel 90.