Overflow Prevention Valve Positioning in Saddle-Riding Vehicle Fuel Tanks
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Solution Overview
Problem
Saddle-riding type vehicles face challenges in preventing liquid fuel leakage and reducing fuel vapor discharge due to variations in fuel tank liquid surface height, which existing overflow prevention valves and canisters do not adequately address.
Innovation Solution
The vehicle is equipped with a fuel tank vent, a canister to capture fuel vapor, and an overflow prevention valve positioned higher than the vent to prevent liquid fuel flow, ensuring effective vapor capture and minimizing vapor discharge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an overflow prevention valve is provided in the fuel vapor passage, then liquid fuel leakage is prevented, but the valve position must be carefully arranged to avoid interfering with the canister's vapor capture function
Solution Approach 1:
The overflow prevention valve is positioned at a higher vertical location than the vent, utilizing the vertical dimension to resolve the conflict between preventing liquid fuel leakage and maintaining vapor capture efficiency. This spatial arrangement allows the valve to intercept liquid fuel flowing upward while permitting vapor to reach the canister horizontally.
Solution Approach 2:
The overflow prevention valve acts as an intermediary component between the vent and the canister, selectively allowing vapor to pass through to the canister while blocking liquid fuel. This mediator role resolves the contradiction by providing differential flow control based on fluid phase.
2Stability of the object's composition
If the fuel tank is arranged below the seat to improve vehicle stability, then the liquid surface height varies largely, but this causes difficulty in preventing liquid fuel discharge from the vent
Solution Approach 1:
The overflow prevention valve is positioned to preemptively intercept liquid fuel before it can reach the vent, counteracting the harmful effect of liquid fuel discharge caused by vehicle posture changes. This preliminary protective action occurs regardless of the fuel tank's vertical position.
Solution Approach 2:
The valve's higher position creates a preliminary barrier that activates before liquid fuel can flow from the tank to the vent, ensuring prevention of discharge even when the liquid surface rises due to vehicle inclination.
3Object-generated harmful factors
If a canister is used to capture fuel vapor, then fuel vapor discharge is reduced, but the canister must be positioned to avoid receiving liquid fuel while maintaining vapor capture effectiveness
Solution Approach 1:
The system segments the flow path into distinct zones: the overflow prevention valve handles liquid fuel interception in the upper region, while the canister captures vapor in the lower region. This segmentation allows each component to perform its function independently without interference.
Solution Approach 2:
Different regions of the fuel vapor passage are assigned different functions based on local quality requirements: the upper region near the vent is optimized for liquid fuel prevention, while the lower region near the canister is optimized for vapor capture. This localized functional differentiation resolves the positioning conflict.
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 effectively prevents liquid fuel leakage and reduces fuel vapor discharge, enhancing the safety and efficiency of the vehicle's fuel management system.
Implementation Method 1
the overflow prevention valve being positioned higher than the vent of the fuel tank
Implementation Method 2
a canister connected to the vent of the fuel tank and configured to capture the fuel vapor
Data Source
AI summary
A saddle-riding type vehicle includes a seat, a fuel tank including a vent and disposed below the seat, a canister connected to the vent, and an overflow prevention valve provided in a fuel vapor passage connecting the vent and the canister. The overflow prevention valve is positioned higher than the vent.