Tire Tread Block Geometry for Wet Steering Stability

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing tires lack improved wet steering stability performance on wet road surfaces, with existing technologies not adequately addressing this issue.

Innovation Solution

A tire design featuring a tread portion with specific block arrangements, including a leading-side corner portion with distinct angles and groove widths, and a belt layer configuration to enhance ground contact pressure uniformity and water drainage, thereby improving hydroplaning resistance and steering stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stress or pressure

If chamfered blocks are used to uniformize contact pressure, then contact pressure uniformity is improved, but wet steering stability performance is not sufficiently improved

Engineering Contradiction:
Improvecontact pressure uniformityVSAvoidwet steering stability performance
Core Design Contradiction:
Stress or pressureVSReliability

Solution Approach 1:

The block corner is divided into a first corner portion and a second corner portion with different angles. The first corner portion has a first angle that is smaller than a second angle of the second corner portion, creating localized geometric variations that improve wet steering stability while maintaining overall contact pressure uniformity

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The block corner is designed with asymmetric geometry where the first corner portion and second corner portion have different angles relative to the block tread surface. This asymmetric design creates optimal water drainage paths while maintaining ground contact pressure distribution

Inventive Principle:
Principle #4Asymmetry

2Object-affected harmful factors

If lateral grooves are made wider to improve water drainage, then hydroplaning resistance is improved, but ground contact pressure uniformity deteriorates

Engineering Contradiction:
Improvewater drainage efficiencyVSAvoidground contact pressure uniformity
Core Design Contradiction:
Object-affected harmful factorsVSStress or pressure

Solution Approach 1:

The lateral groove width is varied along its length, with the groove being wider at the first corner portion side and narrower at the second corner portion side. This localized variation optimizes water drainage at critical areas while maintaining ground contact pressure uniformity in other areas

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The groove width parameter is changed along the length of the lateral groove, creating a gradient from wider at the first corner portion to narrower at the second corner portion. This parameter variation allows simultaneous optimization of water drainage and contact pressure distribution

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3904120B1tyre
Publication Date: 2023.11.15 SUMITOMO RUBBER INDUSTRIES LTD
  • EP3904120B1 patent drawingFigure 1
  • EP3904120B1 patent drawingFigure 2
  • EP3904120B1 patent drawingFigure 3

AI summary

A tyre includes a tread portion including a row of blocks arranged in a tyre circumferential direction divided by lateral grooves (4); each block (5) includes a block tread surface, a first block sidewall surface (7) located on a leading side in a rotation direction of the block, and a leading-side corner portion (10) between the block tread surface and the first block sidewall surface; the leading-side corner portion (10) includes a first portion (11) and a second portion (12) extending in a tyre axial direction; the first portion (11) is formed sharper than the second portion (12); in a plan view of each block, an angle θ1 of the first portion (11) to the tyre circumferential direction is larger than an angle θ2 of the second portion (12) to the tyre circumferential direction; each lateral groove has a groove width (A) at the first portion (11) that is larger than a groove width (B) at the second portion (12).