Flexible Aircraft Corner Piece for Shim-Free Sealed Assembly

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Solution Overview

Problem

The existing rigid corner pieces used in aircraft structural tanks require complex and time-consuming adjustments and machining to fit different aircraft geometries, leading to increased assembly times and costs, and the use of shims complicates the sealing process.

Innovation Solution

A flexible corner piece composed of three fixing plates connected by flexible edges made of hyperelastic material, such as elastomer, allowing for adjustment and sealing without machining or shims, with O-rings and peripheral sealing cords for enhanced sealing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a rigid corner piece is used to ensure structural strength and sealing, then the connection between walls is strong and sealed, but the assembly process becomes complex and time-consuming due to the need for machining or shims to adapt to geometric variations

Engineering Contradiction:
Improveconnection strengthVSAvoidassembly time
Core Design Contradiction:
StrengthVSLoss of time

Solution Approach 1:

The corner piece incorporates flexible edges that allow dynamic adaptation to geometric variations in the aircraft structure. The flexible material enables the rigid fixing plates to adjust their relative positions, eliminating the need for machining or shims while maintaining connection strength and reducing assembly time.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the physical state of the edges from rigid to flexible, allowing the corner piece to accommodate dimensional variations. This parameter change enables the structure to adapt to different geometries without additional manufacturing steps, resolving the contradiction between connection strength and assembly time.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If the corner piece is machined to adapt to each aircraft's geometry, then the fit and sealing are improved, but the manufacturing complexity and cost increase due to additional machining operations and surface treatment

Engineering Contradiction:
Improvefit precisionVSAvoidmanufacturing process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The flexible edges act as compliant elements that absorb geometric variations without requiring precision machining. The flexible material deforms to accommodate dimensional tolerances, achieving good fit and sealing while eliminating complex machining operations and associated surface treatments.

Inventive Principle:
Principle #30Flexible shells and thin films

3Loss of time

If shims are used to adjust the corner piece fit, then machining operations are avoided, but the device complexity increases and sealing application becomes more difficult

Engineering Contradiction:
Improvemachining timeVSAvoidassembly complexity
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The invention extracts the adjustment function from separate shims and integrates it directly into the corner piece through flexible edges. This eliminates the need for additional shim components and simplifies the sealing application process, as the flexible edges provide both adjustment and sealing surfaces in one integrated element.

Inventive Principle:
Principle #2Taking out (Extraction)

4Strength

If a rigid corner piece is used to maintain structural integrity, then the structural strength is ensured, but the adaptability to different aircraft geometries is reduced

Engineering Contradiction:
Improvestructural integrityVSAvoidgeometric adaptability
Core Design Contradiction:
StrengthVSAdaptability or versatility

Solution Approach 1:

The corner piece is segmented into rigid fixing plates for structural strength and flexible edges for adaptability. This segmentation allows each component to perform its specialized function: the rigid plates maintain structural integrity while the flexible edges provide geometric adaptability, resolving the contradiction between strength and versatility.

Inventive Principle:
Principle #1Segmentation

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

Significantly reduces assembly times by accommodating geometric variations and provides a reliable fluid-tight seal, eliminating the need for machining and shim manufacturing, while maintaining surface integrity and simplifying the sealing process.

Implementation Method 1

each of the at least three fixing plates being connected to each of the other at least three fixing plates by an edge made of flexible material, the three fixing plates being made of a material more rigid than the flexible material of the edges allowing movement of one plate relative to another

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4197918B1Flexible corner piece for contributing to a connection between at least three walls of at least one aircraft box
Publication Date: 2024.08.21 AIRBUS OPERATIONS (SAS)
  • EP4197918B1 patent drawingFigure 1~3
  • EP4197918B1 patent drawingFigure 4~5
  • EP4197918B1 patent drawingFigure 6~7

AI summary

- A flexible corner piece intended to contribute to a connection between at least three walls of at least one aircraft fuselage section, as well as to their liquid sealing. - The corner piece (1) comprises at least three fixing plates (P1, P2, P3) and at least three edges (A1, A2, A3) made of flexible material. Each of the at least three fixing plates (P1, P2, P3) is connected to each of the other at least three fixing plates (P1, P2, P3) by an edge (A1, A2, A3) made of flexible material. The edges (A1, A2, A3) made of flexible material ensure a fit of the corner piece without machining or the addition of shims.