Tire Tread Segmentation for Wet Grip via Tan Delta Variation

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Solution Overview

Problem

Current tires designed for sporty road driving face challenges in maintaining optimal grip on both dry and wet surfaces, with existing solutions not fully optimizing grip performance on wet surfaces.

Innovation Solution

A tire design featuring a tread with specific axial zones, where the traditionally wet-grip area is made of a rubber composition suitable for dry ground and vice versa, utilizing a carbon black-based elastomer composition with varying tan δ values to enhance grip on both surfaces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the tire uses a single rubber composition for the tread, then manufacturing complexity is reduced, but grip performance on variable surfaces deteriorates

Engineering Contradiction:
Improvetread manufacturingVSAvoidgrip performance on variable surfaces
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The tread is segmented into multiple axial zones with different rubber compositions. This segmentation enables the tire to deliver optimized grip performance for both wet and dry surfaces by having specialized compositions in different zones, while still maintaining relatively simple manufacturing processes through standardized production methods for each zone type.

Inventive Principle:
Principle #1Segmentation

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

This design achieves a significant improvement in wet grip while maintaining excellent dry grip performance, addressing the limitations of previous tire designs by distributing rubber compositions strategically across the tread.

Implementation Method 1

a first portion made from a rubber composition comprising at least one elastomer and at least one reinforcing filler comprising a carbon black... and a second portion made from a rubber composition comprising at least one elastomer and at least one reinforcing filler... The rubber compositions forming the second portion of the first lateral rib and the second portion of the central rib all have a tan δ0 value which is less than the tan δ0 value of the rubber compositions forming the first portion

Methodology Applied
Scientific EffectViscoelasticity: Viscoelasticity

Implementation Method 2

at least one reinforcing filler comprising a carbon black, the carbon black representing a percentage greater than or equal to 50% and less than or equal to 100% of the weight of the entire reinforcing filler

Methodology Applied
Scientific EffectAdsorption: Adsorption

Data Source

PatentEP3041691B1Tyre comprising an improved tread
Publication Date: 2019.06.26 MICHELIN & CO (CIE GEN DES ESTAB MICHELIN)
  • EP3041691B1 patent drawingFigure 1~2
  • EP3041691B1 patent drawingFigure 3~7
  • EP3041691B1 patent drawingFigure 8~10

AI summary

The invention relates to a tyre comprising a tread that comprises at least one central rib (411-413) and two side ribs (421-422) separated by circumferential grooves (141-144), wherein a first side rib (421), adjacent to the outer axial edge of the tread and at least one (and preferably each) of the central ribs comprise a first portion (4211, 4111, 4121, 4131) of which the axial width exceeds 20% of the axial width of the rib in question made from a rubber composition comprising an elastomer and a reinforcing filler, the majority of which consists of carbon black, and a second, axially adjacent portion (4212, 4112, 4122, 4132), made from a rubber composition comprising an elastomer and a reinforcing filler, the minority of which consists of carbon black, wherein the rubber compositions making up the second portion of the first side rib and the second portion of the central rib all have a value tan 00 that is lower than the value tan 00 of the rubber compositions forming the first portion of the first side rib and the first portion of the central rib, the values tan 00 being measured at a temperature of 0°C and under a stress of 0.7 MPa, wherein the first portion of the central rib extends axially from the outer border of the central rib, the axial width LPC of that portion being, over the entire radial depth of the central rib, greater than or equal to 20% of the axial width LC of the central rib, and wherein the second portion of the central rib is axially adjacent to the first portion of the central rib.