Shim Gap Profiling for Precision Structural Assembly

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Solution Overview

Problem

Existing methods for producing shims to fill gaps between components in structures, such as aircraft or spacecraft parts, are inadequate as they can only measure gaps at end portions, failing to account for larger gaps elsewhere, leading to potential residual gaps and the need for remakes.

Innovation Solution

A method involving precise profiling and deformation analysis of component surfaces before and after positioning, allowing for the calculation of the entire gap size and production of a shim that fits the calculated shape, eliminating the need for gap gauge measurements at edges.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If gap measurement is performed using a clearance gauge at end portions of components, then the measurement process is simple and quick, but the measurement precision is insufficient because gaps in non-end portions cannot be detected

Engineering Contradiction:
Improvegap measurement precisionVSAvoidmeasurement process complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent transitions from one-dimensional point measurement (clearance gauge at end portions) to two-dimensional surface profiling (measuring profiles at multiple positions including end portions and non-end portions). This dimensional expansion enables comprehensive gap detection across the entire component surface, resolving the limitation of traditional measurement methods.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The measurement process is divided into multiple discrete profile measurements at different positions (end portions and non-end portions) rather than a single comprehensive measurement. Each profile measurement captures gap information at specific locations, and the combination of these segmented measurements provides complete gap coverage.

Inventive Principle:
Principle #1Segmentation

2Manufacturing precision

If shim production is based on limited end portion measurements, then the production process is quick and simple, but the manufacturing precision deteriorates because shims do not fit gaps in non-end portions

Engineering Contradiction:
Improveshim fit precisionVSAvoidshim production efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent performs comprehensive profile measurements and calculates the complete gap shape before shim production begins. By determining the full gap geometry in advance through multiple profile measurements, the shim can be manufactured with precise fit from the first attempt, eliminating the need for remaking and improving both precision and efficiency.

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If comprehensive profile measurements are performed at multiple positions before and after positioning, then the gap size calculation precision is improved, but the measurement time and process complexity increase

Engineering Contradiction:
Improvegap size calculation precisionVSAvoidmeasurement time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent implements continuous profile measurements at multiple positions both before and after positioning operations. This continuous measurement approach ensures that gap information is captured at all critical stages, enabling accurate gap size calculation while maintaining efficient production flow by integrating measurements into the positioning process sequence.

Inventive Principle:
Principle #20Continuity of useful action

Data Source

PatentEP4417524B1Method of producing structure
Publication Date: 2026.04.29 SUBARU CORP
  • EP4417524B1 patent drawingFigure 1
  • EP4417524B1 patent drawingFigure 2(A)~2(D)
  • EP4417524B1 patent drawingFigure 3~4

AI summary

A method of producing a structure by coupling a first component to a second component and inserting a shim into a gap formed between the first component and the second component includes: measuring first and second profiles of first and second surfaces of the first and second components before completing positioning of the first and second components to coupling positions; measuring third and fourth profiles of third and fourth surfaces of the first and second components before completing the positioning; performing the positioning by butting the first surface against the second surface; measuring fifth and sixth profiles of the third and fourth surfaces after completing the positioning; calculating a size of the gap based on the first to sixth profiles; producing the shim based on the size of the gap; and coupling the second component to the first component with the shim inserted and the positioning completed.