Variable-Weight Float Valve for Liquid Tank Sealing

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Solution Overview

Problem

Existing valve apparatuses for liquid tanks, particularly fuel tanks in vehicles, face challenges in maintaining a tight seal to prevent liquid leakage without compromising the Shut Off Height (SOH), especially when the valve remains immersed for a prolonged period.

Innovation Solution

A valve apparatus with a variable-weight float, utilizing a weight control system that reduces the float's weight in its second position to enhance sealing force, allowing the float to close the outlet orifice more effectively, thereby increasing the tight-sealing force without altering the Shut Off Height.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the float weight is increased to maintain Shut Off Height, then the valve closure position is maintained, but the tight-sealing force decreases leading to liquid leakage

Engineering Contradiction:
Improveleak-tightnessVSAvoidsealing force
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The float weight is made variable rather than constant. The weight control system dynamically adjusts the float weight based on the float's position: when the float is in the first position (away from outlet orifices), the float has a first weight that maintains proper Shut Off Height; when the float moves to the second position (near outlet orifices), the weight control system reduces the float weight to a second weight, increasing the buoyancy force and thereby increasing the tight-sealing force to prevent liquid leakage.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The physical parameter of float weight is changed based on operational conditions. The weight control system modifies the float's weight parameter from a first weight value to a second weight value (where second weight < first weight) as the float transitions between positions. This parameter change enables the float to generate sufficient sealing force against the outlet orifices without compromising the Shut Off Height setting.

Inventive Principle:
Principle #35Parameter changes

2Force

If the float weight is reduced to increase sealing force, then the tight-sealing force increases, but the Shut Off Height is modified

Engineering Contradiction:
Improvesealing forceVSAvoidShut Off Height
Core Design Contradiction:
ForceVSManufacturing precision

Solution Approach 1:

The float weight is made variable rather than constant. The weight control system dynamically adjusts the float weight based on the float's position: when the float is in the first position (away from outlet orifices), the float has a first weight that maintains proper Shut Off Height; when the float moves to the second position (near outlet orifices), the weight control system reduces the float weight to a second weight, increasing the buoyancy force and thereby increasing the tight-sealing force to prevent liquid leakage.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The float's weight characteristic is segmented into at least two distinct weight states: a first weight when the float is in the first position and a second weight when the float is in the second position. The weight control system manages these segmented weight states, ensuring that the appropriate weight is active at the appropriate position, thus maintaining Shut Off Height precision while providing enhanced sealing force when needed.

Inventive Principle:
Principle #1Segmentation

3Device complexity

If a constant weight float is used, then the device structure is simple, but liquid leakage occurs during prolonged immersion

Engineering Contradiction:
Improvefloat structureVSAvoidleak prevention
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The float weight is made variable rather than constant. The weight control system dynamically adjusts the float weight based on the float's position: when the float is in the first position (away from outlet orifices), the float has a first weight that maintains proper Shut Off Height; when the float moves to the second position (near outlet orifices), the weight control system reduces the float weight to a second weight, increasing the buoyancy force and thereby increasing the tight-sealing force to prevent liquid leakage.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The weight control system is configured to automatically control the float weight based on the float's position without requiring external intervention. The system self-adjusts the float weight from the first weight to the second weight as the float moves between positions, enabling the float to self-optimize its sealing performance while maintaining operational height, thus preventing liquid leakage during prolonged immersion.

Inventive Principle:
Principle #25Self-service

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 solution effectively reduces the risk of liquid leakage by increasing the sealing force on the outlet orifice, ensuring a more reliable closure without modifying the valve's operational height, thus enhancing the valve's leak-tightness and preventing liquid ingress during vehicle rollover or tilting.

Implementation Method 1

the buoyant upward force acting on the float can have a greater effect

Methodology Applied
Scientific EffectBuoyancy: Archimedes' Principle (Buoyancy)

Data Source

PatentEP3184342B1Valve apparatus with a weight control system
Publication Date: 2021.04.14 PLASTIC OMNIUM ADVANCED INNOVATION & RES SA
  • EP3184342B1 patent drawingFigure 1
  • EP3184342B1 patent drawingFigure 2
  • EP3184342B1 patent drawingFigure 3A~3C

AI summary

It is proposed a valve apparatus for use in a liquid tank, the valve apparatus comprising: - a casing defining a main chamber, the main chamber having at least one inlet orifice and at least one outlet orifice; - a float comprising a closure element, the float being movable inside the main chamber between a first position and a second position in which said at least one outlet orifice is closed off by the closure element; - a weight control system configured for controlling the weight of the float by transferring a load in and out from the float, such that the weight of the float in the second position is lower than the weight of the float in the first position.