Pilot Chamber Throttle Valve for Low-Impact Disc Seating
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Solution Overview
Problem
Existing fluid control valves require increased working pressure to seat valve discs on valve seats due to the need for a damper member, which can result in increased size and impact during seating, posing challenges in preventing particle flaking and maintaining cleanliness, especially in semiconductor production.
Innovation Solution
A fluid control valve design that incorporates a throttle portion between the piston and valve body, reducing the discharge rate of fluid from the pilot chamber to slow the piston's displacement speed, allowing the valve disc to be seated at a lower speed without increasing the valve's size, using a throttle path with a cross-sectional area smaller than the opening to manage internal pressure and reduce impact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a damper member is added to reduce impact during valve disc seating, then impact is reduced and flaking is prevented, but the valve size increases due to larger piston or cylinder chamber required to generate sufficient working pressure
Solution Approach 1:
The throttle portion is positioned to close the opening in advance before the valve disc reaches the valve seat, thereby slowing down the piston's movement before impact occurs. This preliminary action reduces the seating speed and impact force without requiring additional cushioning components that would increase valve size.
Solution Approach 2:
The throttle portion creates a gradual pressure reduction effect before the valve disc contacts the valve seat, acting as a built-in cushioning mechanism. This beforehand cushioning slows the piston displacement and reduces impact force without requiring separate damper members or increasing the overall valve dimensions.
2Object-affected harmful factors
If the discharge rate of fluid from the pilot chamber is reduced to slow piston displacement, then impact during seating is reduced, but the time required for valve operation increases
Solution Approach 1:
The throttle portion is designed to be dynamically closed by the piston itself during its movement. As the piston approaches the closed position, the throttle portion gradually closes the opening, creating a dynamic flow restriction that slows displacement only during the critical impact phase while maintaining faster operation during other phases of the cycle.
Solution Approach 2:
The cross-sectional area of the throttle portion is specifically designed to create optimal flow resistance that reduces piston speed during the critical seating phase. The parameter of opening area is changed dynamically during operation, providing sufficient slowdown for impact reduction while minimizing the overall time penalty for valve operation.
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 valve disc can be seated on the valve seat at a low speed, reducing impact and preventing flaking, while maintaining the valve's original size, ensuring cleanliness and durability in fluid control applications.
Implementation Method 1
a throttle portion 70 extending from an outer circumferential part of the piston body portion 60. When the piston 18 is displaced from the valve open position toward the valve closed position by a predetermined distance, the throttle portion 70 covers the opening 86 and a peripheral portion 103 around the opening 86 in the inner wall of the first pilot chamber 64 and forms a throttle path 104
Implementation Method 2
the throttle portion 70 is formed of an elastic piece. The elastic piece is capable of elastically deforming in a direction away from the opening 86 when a fluid flows into the first pilot chamber 64 through the opening 86
Data Source
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AI summary
A fluid control valve (10) comprising a cylinder chamber (14) which includes a first pilot chamber (64) extending from a piston (18) in one of sliding directions. An opening (86) of a first pilot port (84) allowing supply and discharge of fluid is formed in the inner wall of the first pilot chamber (64). The fluid is accommodated in the first pilot chamber (64) when the piston (18) is in a valve open position, and discharged via the opening (86) when the piston (18) is displaced toward a valve closed position. At least one of the piston (18) and a valve body (16) includes a throttle portion (70) forming, between the piston (18) and the valve body (16), a throttle path (104) having a cross-sectional area smaller than the area of the opening (86), after the piston (18) starts being displaced from the valve open position toward the valve closed position.