Collapsible Bump Latch for Miss-Fuel Inhibition
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Solution Overview
Problem
Conventional automotive fuel filling systems cannot accommodate the varying diameters of diesel fuel nozzles without increasing the overall size of the fuel filling system, leading to potential mis-fueling issues between diesel and unleaded gasoline, and existing miss-fuel inhibitors are inadequate for accommodating the size variations of diesel fuel nozzles.
Innovation Solution
A collapsible bump is attached to each latch in the fuel filling system, allowing it to pivot radially inwardly for smaller diesel fuel nozzles and outwardly for larger nozzles, enabling the flapper valve to open without increasing the system's diameter, by deforming when the larger nozzle is inserted.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the latch pivots outwardly for larger diameter nozzles, then the nozzle can be inserted, but the overall diameter of the fuel filling system must be increased
Solution Approach 1:
The collapsible bump allows the latch mechanism to dynamically adjust its position based on nozzle size. For larger 32mm nozzles, the bump collapses inward, enabling the latch to pivot in a way that accommodates the larger diameter without requiring the entire system housing to expand.
Solution Approach 2:
The bump functions as a flexible element that can deform under load. This flexibility allows the mechanism to accommodate larger nozzles by having the bump collapse inward rather than requiring rigid structural expansion of the entire fuel filling system.
2Ease of operation
If a spring-loaded flapper valve with freely movable latch is used, then the system is simple to operate, but it cannot prevent mis-fueling of diesel tanks with unleaded gasoline
Solution Approach 1:
The collapsible bump acts as an intermediary element between the latch and the nozzle. It provides a mechanical interface that translates nozzle insertion into selective latch release, enabling the system to distinguish between diesel and unleaded gasoline nozzles while maintaining ease of operation for authorized fueling.
Solution Approach 2:
The latch mechanism with collapsible bump is pre-configured to prevent mis-fueling by requiring specific nozzle characteristics to release the latch. The system proactively blocks unauthorized fueling attempts (unleaded in diesel tanks) before they can occur, while still allowing authorized fueling (diesel in diesel tanks) to proceed easily.
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 collapsible bump design allows the fuel filling system to accommodate diesel fuel nozzles ranging from 24.5 to 32 millimeters in diameter without increasing the system's size, effectively preventing mis-fueling and ensuring safe refueling of diesel engines with either size nozzle.
Implementation Method 1
A collapsible bump is attached to each latch in the fuel filling system, allowing it to pivot radially inwardly for smaller diesel fuel nozzles and outwardly for larger nozzles, enabling the flapper valve to open without increasing the system's diameter, by deforming when the larger nozzle is inserted.
Implementation Method 2
A spring loaded flapper valve is also oftentimes mounted to the funnel and movable between an open and a closed position and urged towards its closed position by the spring.
Data Source
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AI summary
A fuel inlet assembly for an automotive vehicle having an elongated tubular and cylindrical housing open at each end and defining a port in between the ends of the housing. A flapper valve is associated with the fluid port and is movable between an open and a closed position. At least two latches are pivotally mounted to the housing adjacent the fluid port and movable between a latch position and a release position. The latches engage the flapper valve to prevent the flapper valve from moving to its open position. A flexible bump is attached to each latch so that the bump pivots with its associated latch and each bump protrudes radially inwardly from its associated latch. Each bump has a cam surface winch, when engaged by a fuel nozzle, pivots the bump and its associated latch to the release position. However, the latch is collapsible in a radially outward direction towards its associated latch when that latch is in its release position thus enabling a fuel nozzle to pass past the collapsed bumps and engage the flapper valve. As such, only a fuel nozzle with a predetermined size range will engage the bumps and pivot the latches to an open position and also allow the fuel nozzle to pass the bumps and extend through the fluid port.