Bonded Wing Structure with Floating Fasteners
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In aircraft wing assembly, internal structures face challenges in aligning with exterior surfaces due to minor variations in machining, leading to potential assembly issues, as existing methods lack a system to allow controlled movement of internal structures relative to outer structures during bonding.
Innovation Solution
A partially constrained system is employed, featuring an outer structure with close tolerance holes and an interior structure with oversized holes, utilizing elastomeric grommets and fasteners with channels to inject bonding media between the structures, allowing for controlled positioning and bonding while allowing internal structures to 'float' during assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If internal structures are rigidly constrained during assembly, then alignment precision with exterior surfaces is improved, but assembly complexity and difficulty increase due to compounding machining errors
Solution Approach 1:
The patent applies the dynamics principle by transitioning from a rigid constraint system to a partially constrained system that allows controlled movement. The fastening system enables internal structures to 'float' or move relative to outer structures during assembly, accommodating machining variations dynamically rather than requiring perfect rigid alignment. This reduces assembly complexity while maintaining final bonding precision.
2Ease of operation
If internal structures are allowed to move freely during assembly, then assembly ease is improved, but positioning accuracy deteriorates
Solution Approach 1:
The patent applies parameter changes by modifying the constraint parameters of the fastening system. The system transitions from fully constrained to partially constrained, allowing controlled degrees of freedom. The fasteners provide adjustable positioning that maintains accuracy while enabling ease of assembly through controlled movement capability.
3Manufacturing precision
If close tolerance holes are used in both outer and internal structures, then positioning accuracy is improved, but manufacturing difficulty increases due to compounding errors
Solution Approach 1:
The patent applies local quality by differentiating the tolerance requirements for different parts of the structure. Outer structures maintain close tolerance holes for precise positioning, while internal structures use oversized holes that accommodate machining variations. This localized differentiation of quality requirements reduces overall manufacturing difficulty while maintaining necessary positioning accuracy through the hybrid fastening system.
4Strength
If internal structures are bonded rigidly to outer structures, then structural strength is improved, but assembly flexibility is lost
Solution Approach 1:
The patent applies preliminary action by establishing a partially constrained fastening system before final bonding occurs. This preliminary configuration allows for adjustment and accommodation of machining errors during assembly, while the subsequent bonding process creates the strong permanent connection. The sequence of operations preserves both assembly flexibility and final bonding strength.
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 simplifies and expedites the assembly process by providing flexibility during construction while ensuring accurate and sturdy bonding of wing components, allowing for precise alignment and bonding of internal and external structures within predetermined constraints.
Implementation Method 1
an elastomeric grommet disposed in the oversized hole
Implementation Method 2
curing the bonding media to bond the outer structure to the interior structure
Data Source
AI summary
A bonded structure is described. The bonded structure includes an outer structure including a close tolerance hole associated with a first accuracy level. The bonded structure includes an interior structure comprising an oversized hole associated with a second accuracy level that is different from the first accuracy level. The bonded structure includes an elastomeric grommet disposed in the oversized hole. The bonded structure includes one or more spacers between the outer structure and the interior structure providing a space between the outer structure and the interior structure. The bonded structure includes a fastener positioned in the close tolerance hole and in the oversized hole. The bonded structure includes a bonding media disposed in the space between the outer structure and the interior structure via one or more channels of the fastener. The bonding media, elastomeric grommet, and oversized hole collectively position the interior structure relative to the outer structure.