Tire Tread Narrowed Grooves for Air Column Resonance Reduction

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Solution Overview

Problem

Existing tire designs that incorporate side branch or Helmholtz-type resonators to reduce air column resonance sound compromise tread design freedom and lead to uneven wear due to the need for large or complex grooves in the tread land portion.

Innovation Solution

A tire design featuring narrowed grooves in the width direction that communicate with circumferential grooves, providing a damping effect to reduce air column resonance sound without compromising tread design freedom or uniform rigidity, achieved by maintaining a specific cross-sectional area ratio and geometry that converts kinetic energy into thermal energy through viscosity friction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If side branch type resonator or Helmholtz-type resonator is provided in the land portion, then air column resonance sound is reduced, but the degree of freedom in design of the tread is limited and rigidity distribution becomes non-uniform

Engineering Contradiction:
Improveair column resonance soundVSAvoiddegree of freedom in design of the tread
Core Design Contradiction:
Object-affected harmful factorsVSAdaptability or versatility

Solution Approach 1:

The invention divides the continuous circumferential groove into multiple segments by providing groove portions that extend in the width direction, creating a segmented structure that disrupts the air column resonance path while preserving tread design flexibility

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention introduces width direction extension of grooves into the tread design, adding a dimensional element that breaks the circumferential continuity without requiring complex vertical or lateral groove structures in the land portion

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Object-affected harmful factors

If side branch type resonator or Helmholtz-type resonator is provided in the land portion, then air column resonance sound is reduced, but rigidity distribution of the land portion becomes non-uniform causing uneven wear

Engineering Contradiction:
Improveair column resonance soundVSAvoidrigidity distribution of the land portion
Core Design Contradiction:
Object-affected harmful factorsVSStability of the object's composition

Solution Approach 1:

The circumferential groove is segmented into multiple portions separated by land portions, creating a discontinuous structure that interrupts air column resonance while maintaining uniform rigidity distribution across the tread

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The groove portions are strategically positioned to extend only in specific regions (shoulder land portions and/or center land portion) rather than uniformly across all land portions, locally disrupting resonance paths while preserving overall rigidity uniformity

Inventive Principle:
Principle #3Local quality

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

The tire effectively reduces air column resonance sound while maintaining tread design flexibility and preventing uneven wear by using narrowed grooves that absorb sound waves via viscosity friction, without the need for complex resonators in the tread surface.

Implementation Method 1

providing a damping effect to reduce air column resonance sound without compromising tread design freedom or uniform rigidity, achieved by maintaining a specific cross-sectional area ratio and geometry that converts kinetic energy into thermal energy through viscosity friction

Methodology Applied
Scientific EffectViscosity friction: Viscous Heating

Implementation Method 2

The tire effectively reduces air column resonance sound while maintaining tread design flexibility and preventing uneven wear by using narrowed grooves that absorb sound waves via viscosity friction

Methodology Applied
Scientific EffectViscosity friction: Viscous Heating

Data Source

PatentEP3590733B1tire
Publication Date: 2020.10.28 BRIDGESTONE CORP
  • EP3590733B1 patent drawingFigure 1~2
  • EP3590733B1 patent drawingFigure 3A~3B
  • EP3590733B1 patent drawingFigure 4~5

AI summary

There is provided a tire that is capable of maintaining a degree of freedom in design of a tread and inhibiting uneven wear in the tread while reducing air column resonance sound. The tire has, in a tread surface, at least one circumferential groove continuously extending in a tire circumferential direction, and a shoulder land portion partitioned with the circumferential groove and a tread ground contact edge, the shoulder land portion has a width direction groove that extends in a tire width direction and via which the circumferential groove communicates with the tread ground contact edge, the width direction groove has, in the width direction groove, a narrowed groove that communicates with the width direction groove and that has a smaller cross-sectional area than the width direction groove, and the cross-sectional area of the narrowed groove and a cross-sectional area of the width direction groove satisfy a relational expression of "0.08 ≤ the cross-sectional area of the narrowed groove/the cross-sectional area of the width direction groove ≤ 0.80".