Airframe Component Assembly Using Over-Press Tool Alignment

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The production of aircraft airframe components faces challenges in achieving precise assembly due to difficulties in producing separate sections within tight tolerance bounds, often requiring lengthy and expensive shimming processes and dedicated assembly tools.

Innovation Solution

The use of a frame machining fixture with precision-ground blocks and locator pins, along with a CNC milling machine, to accurately machine longeron landings and attach components to a jig with packer material applied to achieve precise alignment and tolerance, reducing the need for shims and dedicated tools.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If separate airframe sections are produced using traditional dedicated assembly tools, then assembly operations can be carried out, but the production precision and tolerance bounds are insufficient, requiring lengthy and expensive shimming processes

Engineering Contradiction:
Improveassembly precisionVSAvoidshimming process time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent applies preliminary action by pre-machining longeron landings on frames with high precision before assembly, and by preparing packer material in advance to compensate for dimensional variations. This preliminary preparation eliminates the need for time-consuming shimming operations during the actual assembly process, as components are already positioned and sized correctly.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the dimensional parameters of components by providing adjustable-length longerons and packer material of varying thicknesses. This allows precise compensation for manufacturing tolerances and dimensional variations in frames and longerons, enabling tight tolerance assembly without requiring extensive shimming operations.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If separate airframe sections are produced using traditional dedicated assembly tools, then assembly operations can be carried out, but the process requires lengthy and expensive shimming processes to fill gaps

Engineering Contradiction:
Improveassembly precisionVSAvoidassembly complexity
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent applies universality by using a single, versatile jig structure that can accommodate multiple frames and longerons of different configurations. The jig includes adjustable pick-up devices and positioning mechanisms that can adapt to various component arrangements, eliminating the need for multiple dedicated assembly tools for different assembly operations.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent introduces packer material as an intermediary element between frames and longerons to compensate for dimensional variations and positioning errors. This packer material acts as a mediator that absorbs tolerance accumulations and enables precise positioning without requiring complex adjustment procedures or multiple specialized tools.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If conventional rigid metal jigs are used for assembly, then components can be supported, but the device complexity and cost increase

Engineering Contradiction:
Improvecomponent support capabilityVSAvoidassembly tool complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent applies dynamics by using adjustable and movable components in the jig structure, including adjustable pick-up devices that can be repositioned along the jig structure, and components that can be easily assembled and disassembled. This dynamic design allows the same jig to accommodate different component configurations without requiring complex, dedicated fixtures for each assembly type.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent segments the assembly jig into modular components including a main jig structure, separate pick-up devices, and independent positioning mechanisms. This segmentation allows each component to be optimized independently, simplifies manufacturing and maintenance, and enables flexible reconfiguration for different assembly operations without requiring an entirely complex monolithic structure.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3134786B1Production of airframe components
Publication Date: 2021.10.13 BAE SYSTEMS PLC
  • EP3134786B1 patent drawingFigure 1~2
  • EP3134786B1 patent drawingFigure 3
  • EP3134786B1 patent drawingFigure 4

AI summary

Disclosed is a method of producing an airframe component (8, 10, 12). The method comprises: providing an initial component having a first surface; providing an over press tool (96) having a second surface complementary to the first surface; applying, to the first surface, an adhesive (94), one or more layers of a material (90); at least for some time during curing of the adhesive (94), positioning the over press tool (96) such that the second surface is in contact with an outer surface of the material (90) and the material (90) is between the first and second surfaces, and forcing the over press tool (96) against the first surface such a normal force is exerted on the first surface; and, thereafter removing the over press tool (96) from the one or more layers of material (90), thereby providing the airframe component (8, 10, 12).