Aircraft Assembly Insert Structure for Deburr-Free Fastener Holes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The inefficiency and time-consuming process of deburring structural components in aircraft assembly, particularly in wing box assemblies, due to the need to remove and reposition covers for machining operations, which is unnecessary for materials like aluminum and carbon fibre reinforced plastic when high loading capability is not required.
Innovation Solution
Incorporating an insert with a lower material hardness than the surrounding components, which minimizes wear on tools and eliminates the need for deburring by allowing machining on a softer material, enabling hole formation without separating components, and enhancing load transfer through interference fits and mechanical fixation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a machining operation is undertaken on hard structural components to form holes for fasteners, then the structural integrity and loading capability are maintained, but tool wear increases and deburring processes are required
Solution Approach 1:
The structural component is segmented into a hard base material and a softer insert material. The insert is inserted into a cavity in the hard component, creating a composite structure that combines the advantages of both materials - the hard base provides loading capability while the softer insert facilitates easier machining with reduced tool wear.
Solution Approach 2:
The insert is positioned locally at the specific location where machining is required, rather than changing the entire component's material properties. This allows the majority of the component to maintain its hard, load-bearing properties while only the local insert region is softened to facilitate machining operations.
2Productivity
If components are kept assembled during machining operations, then assembly time is reduced, but deburring requires disassembly which increases time consumption
Solution Approach 1:
The material hardness parameter of the insert is changed to be softer than the base component. This parameter change allows machining operations to be performed on the assembled component without requiring disassembly for deburring, as the softer insert material produces less burring and is easier to machine.
3Ease of manufacture
If inserts with lower material hardness are used, then machining ease and tool wear are improved, but the insert material must still provide sufficient structural support
Solution Approach 1:
The solution uses a composite structure combining two different materials - a hard base material providing structural support and loading capability, and a softer insert material providing machining ease. This composite approach allows each material to contribute its advantageous properties while compensating for the other's limitations.
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
This approach reduces the need for deburring, minimizes swarf impact, and simplifies the assembly process by allowing machining and fastening without disassembly, thereby reducing assembly time and tool wear while maintaining structural integrity.
Implementation Method 1
the wear on the tool, for example a drill bit or grinding tool is minimised
Implementation Method 2
The insert may be in an interference fit with the body. Accordingly, the load transfer path between the insert and the body is enhanced in a shear load direction.
Implementation Method 3
The insert may be formed from a cured resin. The insert may be cured in the body during manufacture.
Data Source
Figure 1~2
Figure 3~7
Figure 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.