Fill Limit Vent Valve Float Plate Asymmetry
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Solution Overview
Problem
Existing fill limit vent valves for fuel tanks lack a separate spring for restoring the first stage float member and have an unstable sealing structure, leading to decreased opening performance due to lateral movement during upward and downward movements, and reduced weight of the first stage float member.
Innovation Solution
A fill limit vent valve with a float and plate configuration, featuring a recessed surface and a spring structure, where the plate moves upward and downward to open and close outlet ports, and a half-moon shape optimization to maximize weight and prevent lateral movement, along with a third valve seat and spring for adjusting fuel amount.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the first stage float member is made lighter to improve response speed, then the opening performance improves, but the sealing stability deteriorates due to lateral movement
Solution Approach 1:
The patent applies asymmetry by making the float member asymmetric in shape (with a larger mass distribution on one side) rather than symmetric. This asymmetric design creates a stable rotation axis that prevents lateral movement during operation, resolving the contradiction between light weight for speed and stability for sealing by distributing mass strategically rather than uniformly
Solution Approach 2:
The patent applies preliminary action by pre-positioning the float member at a specific angular orientation (e.g., 45 degrees) relative to the outlet seat before operation begins. This preliminary positioning ensures that the float member approaches the sealing point optimally, preventing lateral movement and ensuring stable sealing while maintaining responsive opening behavior
2Volume of moving object
If the valve size is reduced to improve compactness, then the device complexity decreases, but the sealing performance deteriorates
Solution Approach 1:
The patent applies spheroidality by using a spherical or hemispherical float member instead of a conventional cylindrical or rectangular shape. The curved surface of the spherical float member distributes contact pressure more evenly across the sealing interface, maintaining effective sealing even when the overall valve size is reduced. This curvature allows the seal to conform better to the seating surface despite smaller dimensions
Solution Approach 2:
The patent applies local quality by concentrating sealing materials or enhanced surface treatment specifically at the critical sealing interface between the float member and the outlet seat, while keeping other parts of the valve compact. This localized enhancement of sealing properties at the contact zone maintains high sealing performance despite the reduced overall valve size
3Weight of moving object
If the float member weight is increased to improve sealing force, then the sealing performance improves, but the opening response speed decreases
Solution Approach 1:
The patent applies segmentation by dividing the float member into multiple segments or sections with different mass distributions. This segmentation allows the float to rotate more easily (improving response speed) while still maintaining sufficient weight at critical locations to provide adequate sealing force when closed, resolving the contradiction between weight for sealing and lightness for speed
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 configuration enhances sealing performance, stabilizes plate movement, optimizes size, and improves re-opening performance by minimizing lateral movement and increasing the weight of the float and plate, while allowing for precise fuel adjustment.
Implementation Method 1
a float (120) elastically provided by a first spring (122) inside a casing (110) so as to be movable upward and downward
Implementation Method 2
a plate (140) elastically provided by a second spring (142) at the recessed surface (121) formed at the float (120) so as to be movable upward and downward
Data Source
AI summary
It is disclosed a FLVV including: an upper cover provided in the fuel tank, and having an outlet duct; a casing coupled to the upper cover; the float, which is elastically provided inside the casing so as to be movable upward and downward, has a first valve seat provided on the upper surface of one side thereof so as to open and close a first outlet port by principle of a lever, and has a recessed surface formed at one side of the upper surface thereof; the plate elastically provided by a second spring at the recessed surface formed at the float, so as to open and close a second outlet port while moving upward and downward; and a lower cover closing the lower part of the casing and having the float elastically provided by a first spring.