Aircraft Support Pin Assembly With Floating Pin Alignment
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Solution Overview
Problem
Existing methods for full size determinant assembly of aircraft structures face challenges such as over-constraining, pin binding, and hole misalignments, which hinder accurate positioning and support of aircraft parts during assembly.
Innovation Solution
A support pin assembly and system that includes a clevis with bushings and a pin with a shoulder portion and part support portion, allowing for lateral movement and pin adjustment to prevent binding and misalignments, and enabling full size determinant assembly without over-constraining the build-up.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional assembly jigs and fixtures are used to position and support aircraft structure parts, then positioning accuracy is improved, but pin binding and assembly jig lock occur due to over-constraining
Solution Approach 1:
The support pin assembly incorporates a slideable pin mechanism within bushings, transforming the traditional fixed pin into a dynamic component that can move laterally. This allows the pin to self-adjust and float during assembly, preventing binding while maintaining positioning accuracy. The pin can slide within the bushing to accommodate dimensional variations and assembly tolerances.
Solution Approach 2:
The invention changes the constraint parameters by introducing controlled mobility to the pin. Instead of rigid fixed-position constraints, the pin is allowed to vary its position within the bushing, changing from a static constraint to a dynamic constraint that adapts to assembly conditions, thereby preventing over-constraining.
2Ease of manufacture
If assembly jigs are used to hold single fuselage parts and build modules in one direction, then assembly organization is improved, but hole misalignments occur within the assembly jig
Solution Approach 1:
The bushing acts as an intermediary element between the assembly jig and the support pin. It provides a tolerance zone that absorbs misalignments and allows the pin to self-center, mediating between the rigid jig structure and the dimensional variations in assembled parts, thereby preventing hole misalignment issues.
Solution Approach 2:
The slideable pin mechanism allows dynamic adjustment during assembly, enabling the pin to move and self-align with holes even when there are minor misalignments in the jig or parts, maintaining manufacturing precision despite organizational constraints.
3Device complexity
If traditional fixed pins are used in assembly jigs, then structural simplicity is maintained, but pin adjustment and pin float are not allowed
Solution Approach 1:
The invention introduces a slideable pin mechanism that adds adaptability while maintaining relative structural simplicity. The pin can adjust its position within the bushing, providing float and adaptability without requiring complex adjustment mechanisms, achieving a balance between simplicity and versatility.
4Measurement precision
If pins are rotated in holes or slots during assembly, then positioning is achieved, but pins may get locked in the assembly jig or fixture
Solution Approach 1:
The slideable pin mechanism eliminates the need for rotation by allowing linear sliding movement within the bushing. The pin can be easily inserted and positioned by sliding rather than rotating, improving ease of operation while maintaining accurate positioning through the controlled mobility provided by the bushing.
Data Source
AI summary
There is provided a support pin assembly for full size determinant assembly of an aircraft structure. The support pin assembly includes a clevis having a clevis body with a first clevis lug and a second clevis lug, the clevis configured for mounting to an assembly jig. The support pin assembly further includes a first bushing disposed within the first clevis lug, a second bushing disposed within the second clevis lug, and a pin slideably disposed within the first bushing and the second bushing. The pin includes a shoulder portion with a pin groove, and a part support portion configured to fit through a hole in a part of the aircraft structure. The support pin assembly further includes a sleeve bushing slideably disposed over the part support portion, a retainer element coupled to the part support portion, and a gauge assembly configured for coupling to the pin groove.