Pneumatic Tire Asymmetric Sipe Density Tread Stability

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Solution Overview

Problem

Pneumatic tires face challenges in achieving both good steering stability on snow and dry road surfaces, particularly during high-load cornering conditions, due to varying sipe densities affecting rigidity and traction.

Innovation Solution

A pneumatic tire design with mediate land portions having different sipe densities and projecting amounts in the vehicle width direction, where the inner mediate land portion has a higher sipe density and projects more radially than the outer mediate land portion, optimizing sipe distribution and ground contact for enhanced stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If sipe density is large, then steering stability on snow is improved, but rigidity of ribs or blocks is decreased and steering stability on dry road surface at high-load cornering deteriorates

Engineering Contradiction:

Improvesteering stability on snowVSAvoidrigidity of ribs or blocks

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The patent applies local quality by creating different sipe densities in different regions of the tread. Specifically, the inner mediate land portion has a first sipe density optimized for snow traction, while the outer mediate land portion has a second sipe density that maintains rigidity for dry road cornering. This regional differentiation allows each area to perform optimally for its specific function without compromising the other.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The tread is segmented into multiple land portions (inner mediate land portion and outer mediate land portion) with distinct sipe characteristics. This segmentation allows independent optimization of sipe density in each region, enabling the tire to simultaneously achieve good snow performance in the inner region and maintain structural rigidity in the outer region for dry road handling.

Inventive Principle:

Principle #1Segmentation

2Strength

If sipe density is small, then steering stability on dry road surface at high-load cornering is improved, but steering stability on snow deteriorates

Engineering Contradiction:

Improverigidity of ribs or blocksVSAvoidsteering stability on snow

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The patent implements local quality by assigning different sipe densities to different tread regions. The outer mediate land portion uses a lower sipe density (second sipe density) to maintain high rigidity for effective dry road cornering, while the inner mediate land portion uses a higher sipe density (first sipe density) to ensure adequate snow traction. This localized optimization resolves the contradiction between rigidity and snow performance.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The tread structure is divided into functionally distinct segments where the outer mediate land portion is optimized for dry road performance with lower sipe density, while the inner mediate land portion is optimized for snow performance with higher sipe density. This segmentation enables the tire to achieve both dry road cornering stability and snow steering stability simultaneously.

Inventive Principle:

Principle #1Segmentation

3Area of stationary object

If mediate land portion projects more outwardly, then ground contact area is increased improving snow traction, but structural balance deteriorates

Engineering Contradiction:

Improveground contact areaVSAvoidstructural balance

Core Design Contradiction:

Area of stationary objectVSStability of the object's composition

Solution Approach 1:

The patent applies asymmetry by making the inner mediate land portion project more outwardly than the outer mediate land portion. This asymmetric configuration increases the ground contact area on the inner side to improve snow traction, while the outer side maintains a smaller projection to preserve structural balance and handling characteristics during cornering. The asymmetric design allows optimization of snow performance without compromising overall structural stability.

Inventive Principle:

Principle #4Asymmetry

Data Source

PatentUS10427467B2Pneumatic tire

Publication Date: 2019.10.01 TOYO TIRE CORP

AI summary

Provided is a pneumatic tire 1 on which mediate land portions 23a, 23a are formed. Sipes 24 are formed in the mediate land portions 23a, 23b respectively. The mediate land portion 23a disposed inside in a vehicle width direction in a state where the pneumatic tire 1 is mounted on a vehicle has larger sipe density and projects more outwardly in a tire radial direction than the mediate land portion 23b disposed outside in the vehicle width direction in a state where the pneumatic tire 1 is mounted on the vehicle.