Two-Wheel Vehicle Tire With Segmented Tread Rubber

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Tires for two-wheel vehicles face a challenge in achieving high levels of both wet grip performance and abrasion resistance simultaneously, as existing designs compromise on one aspect to improve the other.

Innovation Solution

A tire design with a divided tread section into a center section and two shoulder sections, where the peak temperature of the loss tangent tan δ of the tread rubber in the center section is lower than that of the shoulder sections, utilizing a rubber composition with styrene-butadiene-based rubber and modified conjugated diene-based polymers, and a high silica content to enhance abrasion resistance and wet grip performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the tread is divided into three sections with different rubber compositions, then wet grip performance and abrasion resistance can be improved, but the device complexity increases

Engineering Contradiction:
Improvewet grip performanceVSAvoidtread structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The tread section is divided into three distinct regions: a center section and two shoulder sections. Each section is assigned a specific rubber composition optimized for its functional requirements. The center section uses a first rubber composition optimized for abrasion resistance, while the shoulder sections use a second rubber composition optimized for wet grip performance. This segmentation allows each region to independently perform its specialized function without compromising the other sections.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different rubber compositions are applied to different regions of the tread based on their specific functional requirements. The center section, which experiences high abrasion during straight-line travel, is given a rubber composition with superior abrasion resistance properties. The shoulder sections, which contact the road during cornering and require high grip, are given a rubber composition with superior wet grip properties. This local differentiation of material properties optimizes overall tire performance.

Inventive Principle:
Principle #3Local quality

2Duration of action of stationary object

If the center section uses rubber optimized for abrasion resistance, then tread durability improves, but wet grip performance may deteriorate

Engineering Contradiction:
Improvetread durabilityVSAvoidwet grip performance
Core Design Contradiction:
Duration of action of stationary objectVSReliability

Solution Approach 1:

The tread is segmented into functional zones with different rubber compositions. The center section uses a first rubber composition specifically optimized for abrasion resistance and durability, while the shoulder sections use a second rubber composition optimized for wet grip performance. This segmentation ensures that each section's rubber properties are tailored to its specific functional requirements, preventing the compromise that would occur with a uniform composition.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The rubber composition is differentiated by location within the tread. The center section employs a rubber formulation with properties optimized for resisting abrasion during straight-line travel, while the shoulder sections employ a different formulation optimized for providing high grip during cornering. This local quality differentiation resolves the contradiction by ensuring that durability and wet grip are both optimized in their respective locations.

Inventive Principle:
Principle #3Local quality

3Reliability

If the shoulder sections use rubber optimized for wet grip, then braking performance on wet surface improves, but abrasion resistance may deteriorate

Engineering Contradiction:
Improvebraking performance on wet surfaceVSAvoidabrasion resistance
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The tread is divided into functional segments where the shoulder sections use a second rubber composition optimized for wet grip performance, while the center section uses a first rubber composition optimized for abrasion resistance. This segmentation allows the shoulder sections to provide superior braking performance on wet surfaces without compromising the overall tread durability, as the center section maintains high abrasion resistance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The rubber composition is locally optimized for each tread region's specific demands. The shoulder sections use a rubber formulation with properties that maximize wet grip and braking performance, while the center section uses a formulation that maximizes abrasion resistance. This local quality approach ensures that wet grip performance is improved in the shoulder regions without sacrificing overall tread durability.

Inventive Principle:
Principle #3Local quality

4Ease of manufacture

If a single rubber composition is used for the entire tread, then manufacturing simplicity is maintained, but both wet grip performance and abrasion resistance cannot be optimized simultaneously

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidoverall performance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The tread is segmented into three sections with different rubber compositions to optimize overall performance. While this increases manufacturing complexity compared to a single composition, it enables simultaneous optimization of wet grip performance in the shoulder sections and abrasion resistance in the center section, achieving a level of overall performance that cannot be obtained with a uniform composition.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different rubber compositions are applied to different regions of the tread to match local performance requirements. This local differentiation of material properties allows the tire to achieve superior overall performance by having each region optimized for its specific function, outweighing the additional manufacturing complexity involved in implementing multiple compositions.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3620310B1Two-wheel vehicle tire
Publication Date: 2023.03.08 BRIDGESTONE CORP
  • EP3620310B1 patent drawingFigure 1
  • EP3620310B1 patent drawingFigure 2~3
  • EP3620310B1 patent drawingFigure 4

AI summary

An object of the present invention is to provide a tire for two-wheel vehicle in which both the wet grip performance and the abrasion resistance of the tread are made compatible with each other. The tire for two-wheel vehicle of the present invention includes a pair of bead sections, a pair of side wall sections, and a tread section continuing to the both sidewall sections, the tread section being divided into three by a center section including a tire equatorial plane and a pair of shoulder sections including a tread end in the tire width direction, wherein a tread rubber of the center section and a tread rubber of the shoulder sections each contain a rubber component and satisfy the following formula (1): Peaktemperatureoflosstangenttanδoftreadrubberofthecentersection<Peaktemperatureoflosstangenttanδoftreadrubberoftheshouldersections