Resilient Segmented Flame Barrier for Fuel Tank Filler Neck Flashback Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing filler neck designs for fuel tanks fail to reliably prevent flashback of inflammable fuel vapor mixtures during refueling, especially with ethanol-based fuels, and often require significant space or are prone to wear, while also being expensive.
Innovation Solution
A filler neck with a flame barrier comprising resiliently mounted segments that surround the fuel delivery nozzle outlet pipe, featuring a spring ring for secure mounting and interlaced segments to minimize gaps, which are electrically conductive to dissipate static charges and prevent flashback, and optionally includes a flap for additional sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If rubber-elastic seals are used to seal the filler neck, then sealing efficiency is improved, but the seals are subject to wear and efficiency deteriorates rapidly
Solution Approach 1:
The flame barrier is divided into multiple segments (at least two) that can move independently relative to each other in the radial direction. This segmentation allows the barrier to adapt to the outlet pipe while maintaining sealing through the interlaced structure, eliminating wear issues of rubber seals.
Solution Approach 2:
The flame barrier segments are designed to be movable in the radial direction, allowing dynamic adaptation to the outlet pipe diameter. The interlaced structure enables the segments to shift and conform to variations in nozzle geometry without wearing out.
2Reliability
If brush seals with dense bristle arrangement are used to achieve high gas-tightness, then flashback prevention is improved, but the structure becomes expensive and elaborate
Solution Approach 1:
Instead of using dense bristles, the invention uses a segmented flame barrier with interlaced edges. The segmentation creates multiple sealing zones that achieve gas-tightness without requiring elaborate dense structures, simplifying the overall design.
Solution Approach 2:
The flame barrier segments function as flexible barriers that can deform radially to maintain sealing contact. This approach replaces complex bristle arrangements with simpler flexible segment structures that achieve the same gas-tightness.
3Reliability
If reducing inserts with window-like apertures are used to improve gas recycling efficiency, then refueling safety is improved, but the insert requires significant space and has complex geometry
Solution Approach 1:
The flame barrier is segmented into multiple parts that can be arranged compactly within the filler neck. This segmentation allows the safety function to be achieved with minimal space occupation compared to bulky reducing inserts with apertures.
Solution Approach 2:
The flame barrier segments serve multiple functions: they prevent flashback, allow gas recycling, and adapt to different nozzle sizes. This multi-functionality eliminates the need for separate reducing inserts, saving space within the filler neck structure.
4Reliability
If spiral ring inserts with multiplicity of gas passage gaps are used to prevent flashback, then flashback prevention is improved, but the amount of space required increases
Solution Approach 1:
The flame barrier is divided into segments that create multiple radial sealing zones, achieving flashback prevention in a compact radial arrangement rather than requiring longitudinal space for multiple gaps as in spiral ring inserts.
Solution Approach 2:
Instead of creating multiple gas passage gaps in the longitudinal direction (spiral rings), the invention creates sealing zones in the radial direction through segmented structure. This dimensional change achieves flashback prevention with minimal space occupation.
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 prevents flashback into the fuel tank by ensuring a tight seal and dissipating static charges, while being compact and cost-effective, with the ability to adapt to various nozzle diameters and allowing for easy replacement of parts.
Implementation Method 1
The flame barrier (4) comprises at least two segments (6) which are mounted resiliently in the radial direction of the tubular section (3)... the segments (6) are placed against the contour of the outlet pipe of the fuel delivery nozzle (5)
Implementation Method 2
The segments (6) are electrically conductive and are connected in an electrically conducting manner to an electric ground... dissipating static charges and prevent flashback
Data Source
AI summary
The invention relates to a filler neck (1) for a fuel tank of a motor vehicle having at least one tubular section (3) provided in the region of the filler inlet (2) in order to receive the outlet pipe of a fuel delivery nozzle (5), and a flame barrier (4) which is provided in the tubular section (3) and surrounds the outlet pipe of the fuel delivery nozzle (5) in the inserted state, wherein the flame barrier (4) includes at least two segments (6) which are mounted resiliently in the radial direction of the tubular section (3), the diameter of the opening (7) in the flame barrier (4) for the outlet pipe of the fuel delivery nozzle (5) being smaller in the prestressed state of the segments (6) than the diameter of the outlet pipe of the fuel delivery nozzle (5).