Aircraft Assembly Soft Insert Layout for Deburr-Free Hole Drilling

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Solution Overview

Problem

The inefficiency and time-consuming process of deburring holes in aircraft assembly, particularly in wing box assemblies, due to the need to remove and reposition components, which is unnecessary for materials like aluminum and carbon fibre reinforced plastic, and unsuitable for high loading applications.

Innovation Solution

Using a machining process that forms holes in a material with a lower hardness value than the rest of the component, minimizing wear on tools and eliminating the need for deburring, by employing an insert with a softer material than the main structural component, allowing for seamless load transfer and reduced assembly complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a machining operation is undertaken to drill holes in structural components, then holes are formed to receive fasteners, but deburring is required to remove chaff from around the holes

Engineering Contradiction:
Improvehole formationVSAvoidassembly process complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The structural component is segmented into two distinct material zones: a harder structural material for load-bearing functions and a softer insert material for machining operations. This segmentation allows the softer insert to be machined without generating harmful chaff while the harder structural material maintains its integrity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A softer insert material acts as an intermediary between the machining tool and the harder structural component. The insert absorbs the machining process, allowing holes to be drilled without requiring subsequent deburring operations on the main structural material

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-generated harmful factors

If components are removed to enable deburring operation, then chaff can be removed from holes, but the process becomes inefficient and time consuming

Engineering Contradiction:
Improvechaff removalVSAvoidassembly efficiency
Core Design Contradiction:
Object-generated harmful factorsVSProductivity

Solution Approach 1:

The harmful chaff generation is converted into a benefit by using a softer insert material that produces minimal chaff during machining. The insert's softer nature means that even if chaff is generated, it is easily managed and does not require component disassembly for removal

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The softer insert is pre-installed in the structural component before machining operations. This preliminary action ensures that the insert is in place to absorb machining effects and eliminate the need for subsequent deburring and reassembly operations

Inventive Principle:
Principle #10Preliminary action

3Strength

If tools are used to drill holes in hard structural materials, then holes are formed, but tool wear increases

Engineering Contradiction:
Improvestructural component strengthVSAvoidtool wear
Core Design Contradiction:
StrengthVSLoss of time

Solution Approach 1:

Different local qualities are applied to different parts of the structural component: the main structural material maintains high hardness for strength, while the insert material has lower hardness specifically at the machining zone to reduce tool wear and facilitate hole formation

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3956215B1Aircraft assembly
Publication Date: 2023.11.01 AIRBUS OPERATIONS LTD
  • EP3956215B1 patent drawingFigure 1~2
  • EP3956215B1 patent drawingFigure 3~7
  • EP3956215B1 patent drawingFigure 8~9

AI summary

The present application relates to an aircraft assembly. The aircraft assembly has a first structural component and a second structural component. A fastener fastens the first component to the second component. The first structural component comprises a body and an insert in the body. The insert has a machined hole through which the fastener extends. The material hardness of the insert is lower than the material hardness of the body.