Integrated Fuel Cap Valve for Miniaturization
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Solution Overview
Problem
Existing evaporated fuel treatment devices for vehicles face challenges in miniaturization due to large size and inefficiencies in preventing fuel flowout, particularly when inclined, and lack a negative pressure adjusting valve, making them unsuitable for miniaturized vehicles.
Innovation Solution
A compact evaporated fuel treatment device with a fuel supply cap featuring a communication chamber with cylindrical portions, a positive pressure adjusting valve, a negative pressure adjusting valve, and a spherical rollover valve, which allows communication between the fuel tank and canister only at predetermined pressures, and prevents fuel flowout by closing the positive pressure adjusting valve when the tank is inclined.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the positive pressure adjusting valve and the liquid leakage preventing valve are separately provided and arranged parallel to each other in the lateral direction of the fuel supply cap, then the liquid leakage can be prevented, but the size of the fuel supply cap becomes too large
Solution Approach 1:
The patent combines the liquid leakage preventing valve and the positive pressure adjusting valve into a single integrated valve structure. The valve body houses both functions: the spherical valve element prevents liquid leakage by sealing against the valve seat, while the valve mechanism simultaneously functions as the positive pressure adjusting valve that opens at predetermined pressure to allow evaporated fuel to enter the canister. This merging eliminates the need for separate parallel valves, significantly reducing the fuel supply cap size while maintaining both liquid leakage prevention and evaporated fuel treatment capabilities.
2Reliability
If a spherical valve is used as a valve for preventing liquid leakage, then the liquid leakage can be prevented, but it is necessary to take into account the structure which prevents sticking of a spherical body to a valve seat, making the fuel supply cap more complicated
Solution Approach 1:
The patent merges the spherical liquid leakage preventing valve with the positive pressure adjusting valve mechanism into a single integrated valve. The spherical valve body serves dual purposes: it seals against the valve seat to prevent liquid leakage and simultaneously acts as the moving element for the positive pressure adjusting function. This integration eliminates the need for separate sticking prevention structures for spherical bodies, as the valve design inherently combines both functions in a simple, unified structure.
3Reliability
If the negative pressure adjusting valve is provided to the fuel supply cap in addition to the positive pressure adjusting valve, then the diffusion of evaporated fuel can be controlled, but the fuel supply cap becomes further larger
Solution Approach 1:
The patent makes the integrated valve structure multi-functional by incorporating both liquid leakage prevention and positive pressure adjusting capabilities in a single valve mechanism. The spherical valve element provides liquid sealing, while the same valve structure responds to positive pressure changes to control evaporated fuel flow. This multi-functionality eliminates the need for additional separate valves, achieving evaporated fuel diffusion control without increasing the fuel supply cap size.
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 enables effective treatment of evaporated fuel while maintaining a compact fuel supply cap design, preventing fuel flowout and allowing for miniaturization of the canister, thus addressing the limitations of existing devices.
Implementation Method 1
a positive pressure adjusting valve in one of the cylindrical portions, the positive pressure adjusting valve being opened when an inner pressure of the fuel tank becomes a first predetermined pressure or higher such that the evaporated fuel generated in the fuel tank is supplied to the evaporated fuel storage unit
Implementation Method 2
a negative pressure adjusting valve in the other one of the cylindrical portions, the positive pressure adjusting valve being opened when the inner pressure of the fuel tank becomes a second predetermined pressure or lower such that atmospheric air is supplied to the fuel tank
Implementation Method 3
a spherical rollover valve arranged on a fuel tank inner side of the one of the cylindrical portions, the spherical rollover valve closing the positive pressure adjusting valve when the fuel tank is inclined at an angle equal to or larger than a predetermined angle
Implementation Method 4
an evaporated fuel storage unit storing evaporated fuel using an absorption agent
Data Source
AI summary
An evaporated fuel treatment device is provided to treat evaporated fuel by using a fuel supply cap with a small size while the flowout of fuel can also be suitably prevented. The evaporated fuel treatment device includes a positive pressure adjusting valve which opens when an inner pressure of a fuel tank becomes a predetermined pressure or more, and a spherical rollover valve which closes the positive pressure adjusting valve when the fuel tank is inclined at an angle equal to or larger than a predetermined angle. The positive pressure adjusting valve and the spherical rollover valve are mounted on one cylindrical portion formed on a fuel supply cap.