Aircraft Pylon Wing Attachment Using Shear Pin Fixing Systems
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Solution Overview
Problem
Existing aircraft mounting pylons face challenges in accommodating increasingly larger engine diameters while maintaining ground clearance, leading to difficulties in fitting the pylon and wing attachments due to restricted vertical space and high force transmission requirements, which affects mechanical strength and aerodynamic performance.
Innovation Solution
A compact aircraft assembly featuring a mounting pylon with a primary structure in the form of a box, equipped with a front and rear fixing system comprising vertically oriented bores, shear pins, and bolts that allow for symmetrical arrangement of brackets and bolts to securely attach the pylon to the wing, enabling closer proximity to the wing without compromising mechanical strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the engine diameter is increased to meet bypass rate requirements, then the propulsion efficiency is improved, but the vertical space between the wing element and the engine is reduced, making it difficult to fit the mounting pylon and wing attachments
Solution Approach 1:
The patent repositions the attachment points from a vertical arrangement to a more distributed spatial configuration. The front attachment is positioned at the front of the pylon, the intermediate attachment at the rear, and the rear attachment at the lower rear, creating a three-dimensional attachment pattern that reduces vertical space requirements while maintaining structural effectiveness.
Solution Approach 2:
The mounting system is divided into multiple discrete attachment points (front, intermediate, and rear attachments) rather than a single consolidated attachment. This segmentation allows each attachment to be optimized for specific force transmission paths, enabling compact pylon design while handling large engine diameters and high bypass rates.
2Strength
If the wing box and primary structure are dimensioned to withstand high forces from the engine, then the mechanical strength is improved, but the aerodynamic performance is degraded due to increased structural dimensions
Solution Approach 1:
The patent applies different structural characteristics to different regions of the pylon. The primary structure uses a box configuration with spars and reinforcement ribs for high strength, while the attachment zones incorporate specific reinforcement elements (attachment plates, strengthening ribs) only where needed to handle localized force concentrations. This allows the structure to be sufficiently strong without requiring uniform thickening throughout the entire pylon length.
Solution Approach 2:
The mounting pylon employs composite construction combining different materials and structural forms - the primary box structure with spars and ribs, combined with attachment assemblies featuring plates, pins, and bolts. This composite approach optimizes the strength-to-weight ratio and allows tailored mechanical properties in different regions, maintaining aerodynamic efficiency while ensuring structural integrity under high engine forces.
3Force
If multiple attachments (front, rear, and intermediate) are used to transmit forces, then the force transmission capability is improved, but the device complexity increases
Solution Approach 1:
The attachment system uses standardized components across all three attachment points - each features attachment plates, reinforcement ribs, and pin connections that follow consistent design patterns. This universality allows the complex three-attachment system to be manufactured and assembled using repeated modular units, reducing overall complexity despite the multiple force transmission paths.
Data Source
AI summary
An assembly comprising a wing with lower spars, a mounting pylon having an upper spar and two lateral panels, a front fixing system and a rear fixing system, each comprising a beam pierced with a principal bore and, for each beam, an upper bore traversing the upper spar and a shear pin positioned in the upper bore and in the principal bore. The assembly also comprises, for each fixing system, bolts, the nut of which is accommodated in a secondary hole of the beam and the screw of which traverses the upper spar and the beam in order to be screwed into the nut.