Tire Rolling Resistance Prediction via Load Drum Phase Difference

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Solution Overview

Problem

Current methods for measuring tire rolling resistance are inefficient and costly, particularly in high-volume manufacturing settings, where long testing times and high rotational resistance in existing machines make it difficult to accurately inspect all tires for abnormalities in rolling resistance.

Innovation Solution

A tire rolling resistance prediction method using a device with a load measurement sensor and displacement sensor to calculate the phase difference between load drum position and applied load variations, allowing for quick identification of tires with abnormal rolling resistance by alternately moving the load drum and applying a temperature correction function.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a dedicated rolling resistance testing machine is used to measure rolling resistance with high accuracy, then measurement precision is improved, but device complexity and cost increase

Engineering Contradiction:
Improverolling resistance measurement precisionVSAvoidtesting machine complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent adapts an existing tire uniformity testing machine to perform both uniformity testing and rolling resistance measurement functions. By adding a load measurement sensor to the existing displacement measurement system, the machine achieves multi-functionality without requiring a completely separate dedicated rolling resistance testing machine, thus reducing device complexity while maintaining measurement capability

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

Solution Approach 2:

The patent changes the measurement parameters by introducing load measurement (force in tangential direction) in addition to the existing displacement measurement. This parameter addition allows the existing machine to measure rolling resistance by calculating the relationship between applied load and displacement, transforming a single-function machine into a multi-functional measurement system

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If conventional rolling resistance measurement methods are used, then measurement accuracy is maintained, but testing time increases significantly

Engineering Contradiction:
Improverolling resistance measurement accuracyVSAvoidtesting time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent enables continuous measurement by having the load drum rotate continuously while applying alternating load. This continuous rotation and measurement approach eliminates the need for repeated static measurements, allowing rolling resistance to be measured during continuous tire rotation, thus significantly reducing testing time while maintaining accuracy

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The patent applies periodic alternating load to the rotating tire through the load drum. By periodically varying the load in the tangential direction during continuous rotation, the system can extract rolling resistance information from the periodic response, enabling fast measurement without requiring multiple measurement cycles

Inventive Principle:
Principle #19Periodic action

3Device complexity

If existing tire uniformity machines are used for rolling resistance measurement, then device complexity is reduced, but measurement precision deteriorates due to high rotational resistance

Engineering Contradiction:
Improvetesting machine simplicityVSAvoidrolling resistance measurement accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent extracts and separately measures the load component in the tangential direction using a dedicated load measurement sensor. By isolating this specific force component from the complex multi-axis forces in the testing machine, the system can accurately measure rolling resistance despite the presence of high rotational resistance in the existing machine structure

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a load measurement sensor as an intermediary element between the load drum and the measurement system. This sensor acts as a mediator that specifically detects the tangential force component related to rolling resistance, filtering out the effects of rotational resistance and other interfering forces present in the existing machine structure

Inventive Principle:
Principle #24Intermediary (Mediator)

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 rapid sorting of tires with abnormal rolling resistance, reducing testing time and costs by using existing tire uniformity machines to measure rolling resistance with improved accuracy and efficiency.

Implementation Method 1

when a load drum simulating a travel road surface is brought into compressive contact with a tread surface of the tire

Methodology Applied
Scientific EffectCompressive contact: Compression

Implementation Method 2

a displacement sensor configured to measure a position of the load drum in a load direction

Methodology Applied
Scientific EffectDisplacement measurement: Displacement

Implementation Method 3

calculating a phase difference between a variation of the position of the load drum and a variation of the applied load

Methodology Applied
Scientific EffectViscoelasticity: Viscoelasticity

Data Source

PatentEP3144660B1Method for predicting rolling resistance of tire and device for predicting rolling resistance of tire
Publication Date: 2019.07.10 KOBE STEEL LTD
  • EP3144660B1 patent drawingFigure 1
  • EP3144660B1 patent drawingFigure 2
  • EP3144660B1 patent drawingFigure 3

AI summary

An applied load acting on a tire is varied by alternately moving a load drum in a direction of approaching and leaving the tire. A phase difference between a variation of a position of the load drum and a variation of the applied load is calculated. A tire having an abnormality in rolling resistance is sorted out based on the calculated phase difference.