Aircraft Pressure Bulkhead Splice Alignment Without Drill Jigs
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Solution Overview
Problem
Existing methods for assembling pressure bulkheads in aircraft using drill jigs result in oversized holes, require multiple alignment steps, and lead to nonconforming joining surfaces, increasing production lag and material wastage, especially with carbon fiber components.
Innovation Solution
A method involving virtual fitting and pre-drilling of splice angles to align with pre-drilled holes in the aft pressure bulkhead, followed by precise drilling and installation using fasteners, with optional shims to ensure a circular circumferential splice surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If drill jigs are used to assemble pressure bulkheads with splice angles, then the components can be joined together, but the holes become oversized and the joining surfaces become nonconforming
Solution Approach 1:
The splice angles are pre-drilled with holes before assembly. This preliminary action ensures that the holes are drilled at the correct positions and sizes on the splice angles themselves, eliminating the problem of oversized holes that occurs when drilling through both the pressure bulkhead and splice angles simultaneously using traditional drill jigs.
Solution Approach 2:
The invention uses a digital model of the pressure bulkhead to determine the precise positions for drilling holes in the splice angles. This digital copy or representation allows for accurate hole positioning without requiring physical drill jigs, thereby maintaining manufacturing precision while simplifying the assembly process.
2Measurement precision
If multiple measurement and alignment steps are performed using drill jigs, then the splice angles can be positioned, but production time increases
Solution Approach 1:
The invention replaces the mechanical drill jig system with a digital modeling and calculation system. Instead of using physical fixtures and multiple manual alignment steps, the hole positions on the splice angles are determined through digital calculations based on the pressure bulkhead's digital model, significantly reducing measurement and alignment time while maintaining positioning accuracy.
Solution Approach 2:
By pre-determining the hole positions on the splice angles through digital calculations before assembly begins, the invention eliminates the need for multiple iterative measurement and alignment steps during the actual assembly process, thereby increasing productivity without sacrificing positioning accuracy.
3Ease of manufacture
If the pressure bulkhead and splice angles are repeatedly placed and removed from the jig, then assembly can be completed, but production lag occurs
Solution Approach 1:
The splice angles are pre-drilled with holes at the correct positions before assembly. This preliminary preparation allows the splice angles to be directly attached to the pressure bulkhead without needing to be repeatedly positioned and secured to a drill jig, eliminating production lag while maintaining assembly flexibility.
Solution Approach 2:
The digital model of the pressure bulkhead is used to determine hole positions, replacing the need for physical jig-based positioning. This digital approach allows for quick calculation and positioning without the time-consuming repeated placement and removal operations required by traditional jig-based assembly methods.
4Ease of manufacture
If traditional drilling methods are used with drill jigs, then holes can be drilled through pressure bulkhead and splice angles, but material wastage increases
Solution Approach 1:
The splice angles are pre-drilled with holes at the correct positions and sizes before assembly. This preliminary action ensures that the holes are drilled only where needed and at the correct dimensions, eliminating the material wastage that occurs when drilling oversized holes through both the pressure bulkhead and splice angles simultaneously using traditional methods.
Solution Approach 2:
The digital model of the pressure bulkhead provides precise hole position information, allowing holes to be drilled exactly where needed on the splice angles. This digital guidance eliminates the need for oversized drill bits and excessive material removal, thereby reducing material wastage while maintaining the ability to drill holes effectively.
Data Source
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AI summary
A method (1000) of making a pressure bulkhead assembly (100) of an aircraft includes determining (1024) an optimized position of splice angles such that splice surfaces of the splice angles will form a circumferential splice surface of the pressure bulkhead assembly with an optimized shape. The method further includes performing (1026) a virtual fit between the plurality of splice angles, at the optimized position, and an aft pressure bulkhead. The method also includes determining (1032) splice-angle-hole positions of splice-angle holes to be drilled in each one of the splice angles such that the splice-angle holes will correspond to aft-pressure-bulkhead holes, pre-drilled in the aft pressure bulkhead. The method further includes drilling (1034) the splice-angle holes in each one of the splice angles at the splice-angle-hole positions. The method also includes joining (1038) each one of the splice angles with the aft pressure bulkhead such that the splice surfaces form the circumferential splice surface with the optimized shape.