Multi-Lobe Fuel Tank Seal for Barrier-Layer Interface Tightness

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Solution Overview

Problem

Fuel tanks in vehicles face challenges with fuel leakage and permeability at interfaces between the multilayer tank and components, due to unknown fuel barrier layer positions, leading to high risks of leaks and costly, complex sealing techniques that are difficult to replace.

Innovation Solution

A multilobed seal with multiple protrusions is used, positioned between the fuel barrier layer and components, providing a secure fit and radial compression to ensure impermeability, and a fixing element is attached to the outer layer of the tank for stability, reducing the number of assembly steps and costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional sealing techniques are used to ensure impermeability at tank-component interfaces, then fuel leakage is reduced, but manufacturing cost and assembly complexity increase significantly

Engineering Contradiction:
Improveimpermeability at interfaceVSAvoidsealing device complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The sealing device is divided into distinct functional elements: a sealing element with multiple lobes that contacts the barrier layer, and a separate fastening element that secures the assembly. This segmentation allows each component to perform its specific function optimally while simplifying manufacturing and assembly processes.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The sealing element utilizes a flexible membrane structure with multiple lobes that can deform to conform to the barrier layer surface. This flexible thin-film approach provides effective sealing without requiring complex rigid structures, reducing both device complexity and manufacturing cost while maintaining reliability.

Inventive Principle:
Principle #30Flexible shells and thin films

2Reliability

If elastically pressed gasket is used to seal against the multilayer wall, then sealing is achieved, but extrusion is created on the fuel tank wall increasing assembly complexity

Engineering Contradiction:
Improvesealing effectivenessVSAvoidassembly complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The sealing function is extracted from the tank wall structure itself and implemented through a separate sealing element that contacts the barrier layer. This prevents extrusion of the multilayer wall while achieving effective sealing, as the sealing action occurs at the barrier layer interface rather than within the wall structure.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The sealing element acts as an intermediary between the component and the barrier layer, providing the sealing function without requiring direct contact or pressure between the component and the multilayer wall. This mediator approach eliminates extrusion issues while maintaining sealing effectiveness.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If gasket is welded to the multilayer wall to prevent extrusion, then sealing is secured, but assembly process becomes lengthy and laborious

Engineering Contradiction:
Improvesealing securityVSAvoidassembly speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The welding process is replaced with a mechanical fastening system using a fastening element that secures the sealing element to the component. This substitution eliminates the time-consuming welding operation while maintaining sealing security through mechanical attachment, significantly improving assembly productivity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The sealing element is pre-positioned and secured to the component before assembly with the tank. This preliminary action ensures proper sealing alignment and eliminates the need for time-consuming welding operations during final assembly, improving overall assembly speed while maintaining sealing reliability.

Inventive Principle:
Principle #10Preliminary action

4Reliability

If component is permanently attached to the tank, then sealing is maintained, but component replacement becomes difficult without damaging the sealing device

Engineering Contradiction:
Improvesealing maintenanceVSAvoidcomponent replaceability
Core Design Contradiction:
ReliabilityVSEase of repair

Solution Approach 1:

The sealing system is segmented into a reusable sealing element and a replaceable component. The sealing element remains permanently attached to maintain sealing, while the component can be independently replaced by detaching from the sealing element, facilitating easy repair without damaging the sealing device.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The connection between the component and sealing element is designed to be dynamically changeable - permanently secured for sealing purposes but mechanically detachable for replacement. This dynamic design allows the system to transition between sealed operation mode and maintenance mode, enabling component replacement without damaging the sealing element.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4065401B1Multi-lobe seal and sealing device comprising such a seal
Publication Date: 2023.09.06 PLASTIC OMNIUM ADVANCED INNOVATION & RES SA
  • EP4065401B1 patent drawingFigure 1~2
  • EP4065401B1 patent drawingFigure 3~4
  • EP4065401B1 patent drawingFigure 5~6

AI summary

The invention relates to a multilobe seal (100) for a sealing device (1) for sealing an opening (3) in a wall (10) of a fuel tank (4), the wall (10) of multilayer structure having at least one layer of fuel-barrier material (11) and an opening (3) in the wall (10) of multilayer structure, the multilobe seal (100) being impervious to fuel and able to be positioned in contact (11A), at the opening (3) in the wall (10) of multilayer structure of the fuel tank (4), between the layer of fuel-barrier material (11) of the wall (10) of multilayer structure of the fuel tank (4) and a component (2). According to the invention, the multilobe seal (100) comprises, on the face (103) able to be in contact (11A) with the layer of fuel-barrier material (11) of the wall (10) of multilayer structure, at least two protrusions (104, 104A), one (104) of which bears (11A) on the layer of fuel-barrier material (11) of the wall (10) of multilayer structure.