Synchronizer Ring Adhesive Strength Testing for Reproducible QA

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Solution Overview

Problem

Current methods for determining the strength of the adhesive connection between a synchronizer ring and a friction lining are not reproducible and depend on manual skill, making them unreliable for quality assurance in motor vehicle transmissions.

Innovation Solution

A method using a tension/compression testing machine with a holding device and a connecting body to apply a second adhesive connection, allowing for the measurement of the force at which the connection between the synchronizer ring and the friction lining breaks, providing a reproducible and automated test.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a manual knife detachment test is used to check adhesive connection strength, then the test can be performed with simple equipment, but the test results depend on manual skill and are not reproducible

Engineering Contradiction:
Improvesimplicity of test equipmentVSAvoidreproducibility of test results
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent replaces the manual mechanical knife detachment test with an automated tensile/compression testing machine that applies controlled forces to measure adhesive connection strength. This substitution eliminates manual skill dependencies while providing quantifiable, reproducible test results through standardized mechanical testing procedures.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent transforms the qualitative manual detachment test into a quantitative measurement by introducing controlled test parameters such as application force, separation speed, and force measurement. These parameter changes enable precise, reproducible assessment of adhesive strength that is independent of operator skill.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If a manual knife detachment test is used, then the test procedure is simple to perform, but the test results lack precision and cannot provide exact strength values

Engineering Contradiction:
Improvesimplicity of test procedureVSAvoidprecision of strength measurement
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent replaces the imprecise manual knife test with a mechanical testing system equipped with force sensors and controlled displacement mechanisms. This system provides precise measurement of adhesive strength through standardized tensile or compression testing, eliminating the subjectivity and imprecision of manual methods.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent incorporates force measurement and data recording systems that provide real-time feedback during the testing process. This feedback mechanism enables precise determination of adhesive strength by continuously monitoring the force required to detach the friction lining, with results recorded for quantitative analysis.

Inventive Principle:
Principle #23Feedback

3Measurement precision

If automated testing equipment is used to improve measurement precision, then reproducible test results are achieved, but the device complexity increases

Engineering Contradiction:
Improveprecision of strength measurementVSAvoidcomplexity of testing equipment
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent employs a universal tensile/compression testing machine that can perform multiple types of adhesive strength tests (tensile, compression, shear) using the same basic equipment. This multi-functionality reduces overall device complexity compared to requiring separate specialized equipment for each test type, while maintaining high measurement precision.

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

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables a precise and reproducible assessment of the adhesive connection strength, independent of manual skill, and allows for the identification of the weakest link in the connection, improving quality assurance in motor vehicle transmissions.

Implementation Method 1

measuring the force at which the connection between the connecting body and the synchronizer ring breaks

Methodology Applied
Scientific EffectAdhesive bond failure: Adhesive

Data Source

PatentEP3754219B1Method for determining the strength of an adhesive connection between a synchronizing ring and a friction lining
Publication Date: 2022.08.03 DIEHL METAL STIFTUNG & CO KG
  • EP3754219B1 patent drawingFigure 1
  • EP3754219B1 patent drawingFigure 2
  • EP3754219B1 patent drawingFigure 3a~3c

AI summary

The invention relates to a method for determining the strength of a first adhesive bond (K1) made from a first adhesive between a synchronizer ring (4) and a friction lining (7) and/or the strength of the friction lining (7) bonded to the synchronizer ring (4) comprising the following steps: providing a tensile/compression testing machine with a holding or support device (1, 2, 11) for holding the synchronizer ring (4) and a connecting body (6) attached to a movable crossbeam of the tensile/compression testing machine, which has a counter surface (10) designed to correspond to the free surface (9) of the friction lining (7), applying a second adhesive to the surface (9) and/or the counter surface (10) and producing a second adhesive bond (K2) between the connecting body (6) and the friction lining (7) under predetermined conditions, so that a bond is formed between the connecting body and the synchronizer ring.Moving the crossbeam relative to the holding or support device (1, 2, 11) so that an increasing force (FZ) is exerted on the connection, and measuring the force (FZ) at which the connection between the connecting body (6) and the synchronizing ring (4) breaks.