Roll Over Vent Valve Segmentation Dynamics
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Solution Overview
Problem
Existing roll-over vent valves face challenges in ensuring positive opening when the fuel level drops or the vehicle returns to its normal position, and they often result in slow fuel tank airing, which can lead to pressure drop-related damage and environmental issues.
Innovation Solution
A roll-over vent valve with a pressure retention device and a one-way fluid inlet valve that allows high flow rates during under-pressure conditions, featuring a flexible seal that increases flow area upon pressure drop, ensuring the valve opens to vent the fuel tank effectively and seals during rollover or excessive fuel entry.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the vent outlet aperture is made large to increase venting capacity, then the venting efficiency is improved, but the closing force on the valve increases making positive opening difficult
Solution Approach 1:
The valve system is segmented into two separate valves: a main vent valve with large aperture for high-capacity venting, and a separate one-way inlet valve with smaller aperture for controlled airing. This segmentation allows each valve to be optimized for its specific function without the trade-off present in a single valve design.
Solution Approach 2:
The one-way inlet valve incorporates a flexible seal that dynamically adjusts the flow area based on pressure differential. Under under-pressure conditions, the flexible seal deforms to increase flow area, enabling high flow rates when needed while maintaining sealing capability during normal operation.
2Reliability
If a bleed aperture is formed to enable fuel tank airing, then the risk of tank damage is reduced, but the airing rate becomes significantly slow
Solution Approach 1:
The one-way inlet valve uses a flexible seal that dynamically changes the effective flow area in response to pressure differential. During under-pressure conditions, the seal deforms to create a larger opening, enabling high flow rates for rapid airing while maintaining sealing during normal pressure conditions.
Solution Approach 2:
The flexible seal changes its physical state (deformation) in response to pressure parameter changes. Under under-pressure, the seal deforms to increase flow area, transforming the valve from a sealed state to a high-flow state, thereby achieving rapid airing when needed.
3Reliability
If the valve is designed to seal tightly during rollover, then fuel leakage prevention is improved, but the valve may fail to open positively when fuel level drops or vehicle returns to normal position
Solution Approach 1:
The sealing function is segmented between two valves: the main vent valve provides primary sealing during rollover, while the one-way inlet valve provides secondary sealing and controlled airing capability. This segmentation ensures that tight sealing during rollover does not prevent positive opening when conditions change.
Solution Approach 2:
The one-way inlet valve acts as an intermediary mechanism that facilitates controlled pressure equalization. By providing a controlled pathway for pressure relief, it prevents excessive pressure differential that could interfere with the main valve's opening operation while maintaining fuel leakage prevention.
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 prevents fuel tank damage by allowing rapid airing during pressure drops, minimizing the risk of leaks and environmental harm while ensuring the valve seals during rollover or excessive fuel entry, thus enhancing safety and environmental protection.
Implementation Method 1
a one-way fluid inlet valve being in flow communication with said fluid outlet to allow fluid flow towards said fluid inlet at a substantially high flow rate at the event of under-pressure at the fluid inlet
Implementation Method 2
a float member received within the housing and axially displaceable between a sealed position wherein a sealing member thereof sealingly bears against the valve seating of the outlet aperture
Implementation Method 3
a pressure-retention device extending intermediate the valve seating and the fluid outlet, to thereby shut fluid flow therebetween as long as pressure differential between the fluid inlet and the fluid outlet does not exceed a minimal pressure threshold
Data Source
AI summary
A roll-over vent valve comprising a housing formed with a fluid inlet and a fluid outlet, a valve seating bounding an outlet aperture of the housing, a float member received within the housing and axially displaceable between a sealed position wherein a sealing member thereof sealingly bears against the valve seating of the outlet aperture to seal the fluid outlet, and an open position wherein the sealing member is disengaged from the valve seating whereby the fluid outlet is in flow communication with the fluid inlet. There is further provided a pressure-retention device extending intermediate the valve seating and the fluid outlet, to thereby shut fluid flow therebetween as long as pressure differential between the fluid inlet and the fluid outlet does not exceed a minimal pressure threshold. The valve further comprises a one-way fluid inlet valve being in flow communication with said fluid outlet to allow fluid flow towards said fluid inlet a substantially high flow rate at the event of under-pressure at the fluid inlet.