Tyre Tread Chamfer Layout for Dry Grip and Low Rolling Noise

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Solution Overview

Problem

There is a constant need to improve the performance of 'four-season' tires in terms of grip compromise between dry ground, snow-covered ground, and wet ground, while also reducing rolling noise, without degrading other performance aspects.

Innovation Solution

The tire features chamfered trailing edges of tread patterns with specific correlations between tread pitches and chamfer widths, along with a surface notch rate between 0.35 and 0.60, to enhance grip on dry ground and maintain performance on snowy and wet surfaces, while minimizing rolling noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the tread pattern uses aggressive notching and grooves to enhance grip, then grip performance on slippery surfaces improves, but rolling noise increases due to irregular contact

Engineering Contradiction:
Improvegrip on slippery groundVSAvoidrolling noise
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent implements different groove configurations and notch rates in different zones to locally optimize for grip while controlling noise. Specific areas have higher notching for grip, while other areas maintain smoother profiles for noise reduction. The varying groove depths create a gradient that balances these competing requirements.

Inventive Principle:
Principle #3Local quality

2Object-generated harmful factors

If the tread pattern uses irregular groove distribution to reduce rolling noise, then rolling noise is reduced, but grip performance on various surfaces becomes compromised

Engineering Contradiction:
Improverolling noiseVSAvoidgrip on various surfaces
Core Design Contradiction:
Object-generated harmful factorsVSReliability

Solution Approach 1:

The groove distribution is optimized locally in different zones rather than uniformly across the tread. This allows noise reduction in areas where grip requirements are lower, while maintaining aggressive groove patterns in areas critical for grip. The first and second patterns have different groove distributions tailored to their specific functions.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4126565B1Tyre having a tread optimized in terms of grip on dry ground
Publication Date: 2023.10.18 MICHELIN & CO (CIE GEN DES ESTAB MICHELIN)
  • EP4126565B1 patent drawingFigure 1
  • EP4126565B1 patent drawingFigure 2~3
  • EP4126565B1 patent drawingFigure 4

AI summary

The invention relates to a tyre having a tread comprising at least two tread pattern elements (MA, MB) distributed periodically in the circumferential direction at spacings (PA, PB). Each tread pattern element is formed of three portions (Z1, Z2, Z3) that each define a volumetric element, the trailing edge corner of which is the one that is common to the tread surface and is the last to leave the contact patch of the tyre running on the ground. Each trailing edge corner is chamfered in the portions Z1 and/or Z2 and/or Z3, the widths of the chamfers of the trailing edge corners (LCAi, LCBi, i ranging from 1 to 3) of the tread pattern elements (MA, MB) of respective spacings (PA, PB) satisfy the following inequalities: a) 0.8*PA/PB≤LCA1/LCB1≤PA/PB*1.2 for the portion Z1, b) 0.8*PA/PB≤LCA2/LCB2≤PA/PB*1.2 for the portion Z2, c) 0.8*PA/PB≤LCA3/LCB3≤PA/PB*1.2 for the portion Z3. Furthermore, the surface void ratio TES is at least 0.35 and at most equal to 0.60.