Aircraft Structural Joining with Staged Drilling and Chip Cleaning

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Solution Overview

Problem

Conventional methods for joining aircraft structural components, such as fuselage panels and segments, face inefficiencies due to inadequate clamping forces allowing metallic chips to lodge between parts during drilling, increasing assembly time and costs.

Innovation Solution

A process involving temporary clamping with Cleco fasteners, drilling pilot holes, removing temporary fasteners, cleaning, and then using automated systems to drill and install permanent fasteners, ensuring increased structural integrity and reducing burr accumulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If temporary fasteners (Cleco fasteners) are used to clamp parts during drilling, then parts alignment is maintained, but inadequate clamping forces allow metallic chips to lodge between parts

Engineering Contradiction:
Improveparts alignmentVSAvoidmetallic chips lodging
Core Design Contradiction:
Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by first drilling a subset of holes (first plurality of holes) while parts are temporarily clamped, then removing temporary fasteners and cleaning chips, before drilling the remaining holes. This staged approach prevents chip accumulation that would occur if all holes were drilled while clamped, while still maintaining alignment during the critical first drilling phase.

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If all holes are drilled while parts are temporarily clamped, then alignment is maintained throughout, but assembly time increases due to chip removal requirements

Engineering Contradiction:
ImprovealignmentVSAvoidassembly time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The drilling process is segmented into two distinct phases: first, drilling a subset of holes (first plurality of holes) while parts are clamped; second, removing temporary fasteners, cleaning chips, then drilling the remaining holes (second plurality of holes). This segmentation allows chip removal to occur between drilling operations rather than requiring interruption of the entire process, reducing total assembly time while maintaining precision.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary drilling of a subset of holes while parts are clamped, then removes temporary fasteners and cleans chips before completing the remaining holes. This preliminary action approach allows alignment to be established and maintained during the critical first phase, then enables efficient chip removal without requiring re-clamping, thereby reducing overall assembly time.

Inventive Principle:
Principle #10Preliminary action

3Object-generated harmful factors

If temporary fasteners are removed and parts are re-clamped for subsequent drilling, then chip removal is enabled, but alignment precision may be compromised

Engineering Contradiction:
Improvechip removalVSAvoidalignment precision
Core Design Contradiction:
Object-generated harmful factorsVSManufacturing precision

Solution Approach 1:

The patent drills a first plurality of holes while parts are temporarily clamped, then removes temporary fasteners and cleans chips. The key insight is that subsequent drilling of the second plurality of holes is performed without re-clamping, using the already-drilled holes and installed fasteners as reference points. This preliminary action of drilling the first set of holes establishes permanent reference points that maintain alignment precision throughout the remaining operations.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2745955B1Process for joining aircraft structural components
Publication Date: 2024.04.24 EMBRAER SA
  • EP2745955B1 patent drawingFigure 1A~1B
  • EP2745955B1 patent drawingFigure 2

AI summary

A process for joining parts together is provided by positioning and temporarily clamping parts to be joined together. A number (n) of pilot holes may then be drilled through the temporarily clamped parts (e.g., by means of Cleco fasteners), wherein the number (n) of pilot holes is less than a total number (N) of holes required to be drilled to allow the parts to be joined together by permanent fasteners and to receive temporary fasteners therein. A remaining number (η) of holes to achieve the total number (N) of holes required for the parts to be joined together by permanent fasteners may thereafter be drilled so that permanent fasteners may be installed both, by automated system, in the number (n) of pilot holes and the remaining number (η) of holes that have been drilled to thereby permanently join the parts together.