Wave-Profile Diaphragm Valve for Stable Low-Pressure Flow Control
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Solution Overview
Problem
Conventional diaphragm-actuated fluid control valves face challenges in achieving significant lift changes relative to pressure differences, especially in ultralow temperature regions, leading to unstable flow rate control and increased costs due to diaphragm thickness and diameter considerations.
Innovation Solution
A diaphragm with a mountainous-wave portion having N + 0.5 elevated portions, formed from a thin stainless steel plate, which allows for increased lift changes without reducing thickness, enabling stable flow rate control and cost reduction by maintaining the same lift as conventional designs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the thickness of the diaphragm is reduced to increase lift change, then the lift change increases, but the diaphragm strength decreases and it may break easily
Solution Approach 1:
The diaphragm incorporates a mountainous-wave portion with curved elastic deformation paths instead of a flat structure. This curvature design allows the diaphragm to achieve larger lift changes through elastic deformation while maintaining structural integrity and strength, resolving the contradiction between lift change and strength.
2Length of moving object
If the diameter of the diaphragm is increased to increase lift change, then the lift change increases, but the part cost increases
Solution Approach 1:
The mountainous-wave portion with its curved geometry enables enhanced elastic deformation and larger lift changes within a compact diaphragm diameter. This curvature-based design achieves the desired lift change without increasing diaphragm size, thereby avoiding increased material costs and maintaining ease of manufacture.
3Speed
If the diaphragm is made thinner to increase responsiveness to pressure difference, then the responsiveness improves, but the stability of flow rate control decreases due to excessive flexing
Solution Approach 1:
The mountainous-wave portion provides controlled elastic deformation through its curved structure. This curvature enables the diaphragm to respond sensitively to pressure differences while the elastic recovery特性 of the curved structure prevents excessive or unstable flexing, thereby maintaining stable flow rate control.
Solution Approach 2:
The invention changes the structural parameters of the diaphragm by introducing the mountainous-wave portion with specific curvature characteristics. This parameter change optimizes the balance between responsiveness (through elastic deformation) and stability (through controlled flexing behavior), resolving the contradiction between these two requirements.
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 modified diaphragm design achieves significant lift changes even in regions with small pressure differences, ensuring stable flow rate control and reducing material costs by allowing for a smaller diaphragm diameter while maintaining performance.
Implementation Method 1
the diaphragm (the innermost portion of the diaphragm with respect to the outermost portion thereof) is typically displaced (flexes) in the up or down direction in accordance with the pressure difference between the pressure of the pressure chamber
Data Source
Figure 1
Figure 2A~2B
Figure 3A~3B
AI summary
Provided is a diaphragm-actuated fluid control valve capable of, even in a region where the pressure difference between the pressures on the upper surface side and the lower surface side of a diaphragm is small, significantly changing the amount of lift of the diaphragm relative to the change in the pressure difference, without reducing the thickness of the diaphragm, and thus is capable of providing a predetermined flow rate and performing stable flow rate control. The control valve has a diaphragm 35 for driving a valve 25. The diaphragm 35 has a mountainous-wave portion 35b formed between an outermost portion 35a and an innermost portion 35c thereof, the mountainous-wave portion having the shape of concentric circles when viewed in a plan view and having N + (0.25 to 0.75) elevated portions that protrude upward or downward when viewed in cross section, where N is a positive integer (1,2,3,...).