Pilot-Chamber Fluid Control Valve for Low-Impact Seating
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Solution Overview
Problem
Existing fluid control valves used in semiconductor production require increased working pressure to reduce impact during valve disc seating, which can lead to larger valve sizes and particle contamination.
Innovation Solution
A fluid control valve design featuring a piston with a pilot chamber and a throttle portion that reduces the discharge rate of fluid as the piston approaches the valve seat, allowing the valve disc to be seated at a lower speed without increasing the valve's size, by forming a throttle path with a cross-sectional area smaller than the opening, thereby reducing the displacement speed and internal pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the area of the pressure receiving surface is increased to achieve higher working pressure for reducing impact during valve disc seating, then the impact reduction is improved, but the size of the piston and cylinder chamber increases
Solution Approach 1:
The cylinder chamber is divided into a main chamber and a pilot chamber. The pilot chamber has a smaller volume and receives fluid at a controlled rate through a throttle portion, allowing it to generate high pressure without requiring a large volume. This segmented approach enables impact reduction through high pressure while keeping the overall valve size compact.
Solution Approach 2:
The pilot chamber acts as an intermediary between the fluid supply and the main cylinder chamber. Fluid is supplied to the pilot chamber first, which then pressurizes and supplies fluid to the main chamber through the throttle portion. This intermediary mechanism allows controlled pressure buildup and discharge rate, reducing impact during valve disc seating without requiring a large pressure receiving surface area.
2Object-affected harmful factors
If the discharge rate of fluid from the pilot chamber is reduced to lower piston displacement speed, then the impact during seating is reduced, but the time required for valve operation increases
Solution Approach 1:
The throttle portion is designed to dynamically control the discharge rate of fluid from the pilot chamber. As the piston moves toward the closed position, the throttle portion maintains a restricted opening that controls the discharge rate, ensuring slow piston displacement and reduced impact during the critical seating phase. This dynamic control allows the system to adapt the discharge rate to the operational requirements, minimizing impact while maintaining efficient operation.
3Object-affected harmful factors
If a damper member is used to reduce impact during valve disc seating, then the impact reduction is improved, but the device complexity increases
Solution Approach 1:
The functions of impact reduction and fluid control are merged into a single integrated system. The pilot chamber with the throttle portion combines the shock absorption function (previously requiring a separate damper member) with the fluid control function. This merging eliminates the need for a separate damper member and its associated complex structure, while still achieving impact reduction through controlled fluid discharge.
Solution Approach 2:
The pilot chamber with the throttle portion serves multiple functions simultaneously: it controls the discharge rate of fluid, regulates piston displacement speed, and reduces impact during valve disc seating. This self-service mechanism eliminates the need for separate damper members and complex shock absorption structures, simplifying the overall device while maintaining impact reduction capabilities.
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 particle contamination, while maintaining the valve's original size, thus ensuring clean fluid flow and improved durability.
Implementation Method 1
at least one of the piston and the valve body is provided with a throttle portion forming, between the piston and the valve body, a throttle path having a cross-sectional area smaller than an area of the opening
Implementation Method 2
a piston configured to slide inside the cylinder chamber in sliding directions under working pressure, and a valve disc displaced together with the piston in an integrated manner to be separated from and seated on a valve seat
Implementation Method 3
The damper member provided for the valve body functions as a shock absorber when brought into contact with the piston. When the valve disc approaches the valve seat as the piston is displaced as described above, the piston comes into contact with the damper member before the valve disc is seated on the valve seat. The valve disc is seated on the valve seat after the piston is further displaced while elastically deforming the damper member.
Data Source
AI summary
In a fluid control valve, a cylinder chamber includes a first pilot chamber extending from a piston in one of sliding directions. An opening of a first pilot port allowing supply and discharge of fluid is formed in the inner wall of the first pilot chamber. The fluid is accommodated in the first pilot chamber when the piston is in a valve open position, and discharged via the opening when the piston is displaced toward a valve closed position. At least one of the piston and a valve body includes a throttle portion forming, between the piston and the valve body, a throttle path having a cross-sectional area smaller than the area of the opening, after the piston starts being displaced from the valve open position toward the valve closed position.