Tire Tread and Belt Structure for Better Cornering Grip

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing pneumatic tires struggle to maintain optimal grip performance during both straight running and cornering.

Innovation Solution

A tire design comprising a tread part with a cap rubber layer made of a rubber composition containing liquid rubber and terpene-based resin, combined with a belt layer of 1 to 4 filament steel cords with a reduced outer diameter, and specific acetone extraction amounts to enhance flexibility and followability on the road surface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional rubber composition and steel cord structure are used, then straight running grip is maintained, but cornering grip performance is insufficient

Engineering Contradiction:
Improvecornering grip performanceVSAvoidtire structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies local quality by creating a cap rubber layer with specific composition (liquid rubber and terpene-based resin) only in the tread surface region that contacts the road during cornering. This localized modification allows the tire to achieve superior cornering grip without redesigning the entire tire structure, thereby improving cornering performance while maintaining acceptable straight running characteristics.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes physical parameters of the steel cord by reducing the outer diameter to 0.45 mm or less and controlling the filament count to 1-4 filaments. These parameter changes reduce the rigidity of the belt layer, enabling better deformation followability during cornering maneuvers, thus improving cornering grip performance without excessive structural complexity.

Inventive Principle:
Principle #35Parameter changes

2Strength

If steel cord rigidity is increased for structural strength, then tire durability improves, but followability on road surface decreases

Engineering Contradiction:
Improvetire structural strengthVSAvoidroad surface followability
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The patent optimizes steel cord parameters by reducing outer diameter to 0.45 mm or less and limiting filaments to 1-4 per cord. This parameter optimization achieves a balance where the steel cord maintains sufficient tensile strength for structural integrity while having reduced rigidity that allows the belt layer to deform and follow road surface contours during cornering, thereby improving followability without sacrificing essential structural strength.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite material strategy by combining the steel cord with a specifically formulated cap rubber layer containing liquid rubber and terpene-based resin. This composite structure allows the steel cord to provide structural strength while the rubber composition provides flexibility and followability, resolving the contradiction between strength and ease of operation.

Inventive Principle:
Principle #40Composite materials

3Reliability

If liquid rubber and terpene-based resin are added to rubber composition, then flexibility and heat generation improve, but manufacturing complexity increases

Engineering Contradiction:
Improvegrip performanceVSAvoidrubber composition processing
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent applies local quality by incorporating liquid rubber and terpene-based resin specifically in the cap rubber layer at the tread surface, rather than throughout the entire rubber composition. This localized application provides the desired flexibility and heat generation for improved grip performance while minimizing the impact on manufacturing complexity, as only a portion of the rubber structure requires these additional components.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses composite material approach by combining liquid rubber, terpene-based resin, and conventional rubber components in the cap rubber layer. This composite formulation achieves enhanced flexibility and heat generation for better grip performance while using established composite material processing techniques that do not significantly increase manufacturing complexity.

Inventive Principle:
Principle #40Composite materials

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

Improves grip performance during cornering by synergistic effects of molecular chain terminal heat generation, uniform dispersion of liquid rubber, reduced steel cord rigidity, and enhanced tread rubber flexibility, resulting in improved followability and heat generation.

Implementation Method 1

molecular chain terminal heat generation

Methodology Applied
Scientific EffectMolecular chain terminal heat generation:

Implementation Method 2

A represents an acetone extraction amount, in % by mass, of the rubber composition

Methodology Applied
Scientific EffectAcetone extraction:

Data Source

PatentEP4703148A1tire
Publication Date: 2026.03.04 SUMITOMO RUBBER INDUSTRIES LTD
  • EP4703148A1 patent drawingFigure 1
  • EP4703148A1 patent drawingFigure 2
  • EP4703148A1 patent drawingFigure 3

AI summary

Provided is a tire comprising a tread part (12) and a belt layer (17), the tread part having at least one rubber layer, wherein a cap rubber layer constituting a tread surface of the tread part is composed of a rubber composition comprising a rubber component, a liquid rubber, and a terpene-based resin, wherein the belt layer has a steel cord consisting of 1 to 4 filaments, wherein an outer diameter D of the filament is 0.45 mm or less, and wherein Y is 0.50 or more and Y/D is 1.6 or more, when Y=A/P is defined, where A represents an acetone extraction amount, in % by mass, of the rubber composition and P represents a polymer amount, in % by mass, in the rubber composition.