Capacity Control Valve Chamber Segmentation for Stable Pressure Control
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Solution Overview
Problem
The accuracy of control in capacity control valves is deteriorated due to the pressure difference between suction and control pressures affecting the valve body's movement, leading to inconsistent control based on solenoid current values.
Innovation Solution
A capacity control valve design where the suction pressure is applied to both the pressure sensitive chamber and the accommodation chamber through a communication hole, allowing precise control of the valve body by balancing the driving force of the solenoid with the biasing force from the pressure sensitive body, while maintaining structural strength and minimizing leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If control pressure Pc is introduced to the accommodation space through a gap between the coupling bar and shaft hole, then the responsiveness is improved, but the pressure difference between suction pressure Ps and control pressure Pc affects the valve body movement and deteriorates the control accuracy
Solution Approach 1:
The patent divides the accommodation space into two separate pressure zones: a first accommodation space that communicates with the suction chamber and a second accommodation space that communicates with the control chamber. This segmentation allows independent pressure control in each zone, preventing the mixing of suction pressure and control pressure that previously caused inaccurate valve body positioning.
Solution Approach 2:
The patent introduces a partition wall as an intermediary structure between the first and second accommodation spaces. This partition wall with its communication hole allows controlled pressure distribution while maintaining separation between the suction pressure zone and control pressure zone, thereby eliminating the harmful pressure difference effects on valve body control.
2Measurement precision
If the valve body is moved by electromagnetic force alone, then the control accuracy is improved, but the responsiveness is reduced due to increased circulation amount of refrigerant required for control
Solution Approach 1:
The patent applies pneumatic principles by utilizing pressure differences between suction pressure and control pressure to generate a biasing force on the valve body through the pressure sensitive body. This pneumatic assistance works together with the electromagnetic force from the solenoid, enabling both high responsiveness and accurate control by combining mechanical pressure-driven motion with electromagnetic positioning.
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 enables precise control of the valve body, reducing the influence of control pressures and improving responsiveness, ensuring accurate adjustment of the valve based on solenoid current, thus enhancing the operational efficiency of variable displacement compressors.
Implementation Method 1
a valve body that forms a main valve in cooperation with a valve seat, the valve body coming into contact with and separating from the valve seat, to close and open a communication between the Pc port and the Ps port by a driving force of a solenoid
Implementation Method 2
a pressure sensitive body that applies a biasing force to the valve body according to a fluid pressure of a fluid surrounding the pressure sensitive body
Data Source
AI summary
A capacity control valve includes a valve housing provided with a Ps port through which a suction fluid at a suction pressure passes and a Pc port through which a control fluid at a control pressure passes; a valve body configured to close and open a communication between the Pc port and the Ps port by a driving force of a solenoid; and a pressure sensitive body that applies a biasing force to the valve body according to a surrounding fluid pressure. An accommodation chamber in which a rear side portion of the valve body is accommodated is provided with a supply passage to which suction fluid is supplied.