Welded Bellows High Vacuum Valve Design
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Solution Overview
Problem
Conventional high vacuum valves with molded metal bellows suffer from poor flexibility and durability due to metal fatigue caused by repeated high fluid-pressure application, leading to reduced product life and increased manufacturing costs.
Innovation Solution
A high vacuum valve design utilizing a welded bellows formed by overlapping annular thin metal sheets, combined with a tubular member, which enhances flexibility and bending properties, allowing for a shorter bellows length that maintains required flexibility for valve operation while reducing manufacturing costs and preventing metal fatigue.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If molded bellows is used to reduce manufacturing cost, then manufacturing cost is reduced, but flexibility and bending property deteriorate
Solution Approach 1:
The invention changes the manufacturing method parameter from pressure-molding to welding process. The welded bellows is formed by welding a plurality of hollow metal half-cylinders along their longitudinal edges, which fundamentally alters the structural formation process and achieves superior flexibility and bending properties compared to molded bellows.
Solution Approach 2:
The invention uses composite construction by assembling multiple hollow metal half-cylinders through welding. This composite approach combines multiple simple components to create a bellows structure that achieves both manufacturing efficiency and superior mechanical properties including flexibility and bending resistance.
2Productivity
If molded bellows is used for mass production, then productivity is improved, but durability deteriorates due to metal fatigue
Solution Approach 1:
The invention changes the structural parameter from molded monolithic structure to welded assembly of multiple half-cylinders. This parameter change eliminates the inherent weaknesses of molded bellows while maintaining mass production capability through standardized welding procedures.
Solution Approach 2:
The bellows is segmented into multiple hollow metal half-cylinders that are welded together. This segmentation allows each component to be manufactured separately and then assembled, improving both productivity through parallel manufacturing and durability through the superior fatigue resistance of the welded construction.
3Reliability
If length of bellows is reduced to improve durability, then durability is improved, but valve member opening capability deteriorates
Solution Approach 1:
The invention changes the flexibility parameter through the welded construction method, enabling the bellows to achieve sufficient flexing capability with a shorter length. The welded structure provides superior elastic recovery and bending properties that allow reduced bellows length while maintaining adequate valve opening capability.
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 design achieves improved durability and extended product life by mitigating metal fatigue and reducing manufacturing costs through the use of a welded bellows with superior flexibility and bending properties, ensuring effective high fluid-pressure resistance.
Implementation Method 1
a welded bellows which is formed by causing a plurality of annular thin metal sheets to be overlapped, and alternately welding outer peripheries of adjacent metal sheets, and inner peripheries of adjacent metal sheets
Implementation Method 2
When such a force in the bending direction is repeatedly applied to the metal bellows, crack or the like is easy to be produced in the bellows by metal fatigue which is brought about by repeated bent-deformation of the bellows
Data Source
AI summary
The high vacuum valve includes a valve housing having a valve flow channel provided in an interior thereof, two ports connected to the valve housing so as to be arranged perpendicular relative to each other, and capable of being communicated with each other through the valve flow channel, a valve member housed in the valve flow channel for opening and closing the valve flow channel, a valve shaft received in the valve flow channel for causing the valve member to perform opening/closing operations, and an assembly comprising a tubular member and a welded bellows and hermetically surrounding a periphery of the valve shaft, the assembly being fixed at one end portion thereof to a rear face of the valve member and fixed at the other end portion thereof to a portion of the interior of the valve housing which is opposed to the rear face of the valve member.