Variable Tread Pattern for Wet Grip Maintenance

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Solution Overview

Problem

Tire tread patterns compromise between stiffness and wet driving performance, leading to reduced water flow through grooves as the tire wears, resulting in decreased aquaplaning resistance and slippage issues during water traversal.

Innovation Solution

A pneumatic tire with a variable tread pattern that changes with wear, featuring inclined lateral grooves and groove voids that transform into unobstructed circumferential grooves as the tire wears, enhancing water flow and maintaining wet performance characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the tread pattern is designed with grooves for water evacuation, then wet driving performance is improved, but as the tire wears the groove depth decreases and water flow capability is reduced

Engineering Contradiction:
Improvewet driving performanceVSAvoidservice life
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The tread pattern is designed to dynamically change its configuration as the tire wears. The groove voids are positioned at specific depths below the tread surface, and as the tread wears down, these voids become exposed and transform into active water evacuation grooves. This dynamic transformation ensures that the tread pattern adapts to the wear state, maintaining water flow capability throughout the tire's service life.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The groove voids are pre-positioned within the tread structure at designated locations before the tire is put into service. These voids are initially hidden beneath the tread surface but are strategically placed so that as the tread wears to a certain extent, the voids become exposed and immediately begin functioning as water evacuation channels. This preliminary positioning ensures that water flow capability is restored as the tire wears.

Inventive Principle:
Principle #10Preliminary action

2Strength

If the tread elements are made stiffer to improve handling, then handling performance is improved, but water flow through the grooves is reduced

Engineering Contradiction:
Improvetread element stiffnessVSAvoidwater evacuation capability
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The tread structure incorporates groove voids at specific locations within the tread elements, creating local variations in the tread's physical properties. These voids are positioned to provide water flow channels without compromising the overall structural integrity and stiffness of the tread elements. The local modification allows the tread to maintain both stiffness for handling and water evacuation capability for wet performance.

Inventive Principle:
Principle #3Local quality

3Reliability

If the initial tread depth is increased to improve wet performance, then aquaplaning resistance is improved, but the tire weight and rolling resistance increase

Engineering Contradiction:
Improveaquaplaning resistanceVSAvoidtire weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The water evacuation function is segmented into two parts: the initial tread grooves visible on the new tire surface, and the groove voids hidden within the tread structure. As the tire wears, the groove voids become exposed and take over the water evacuation function. This segmentation allows the tire to maintain effective water channels without requiring excessive initial tread depth, thereby reducing tire weight and rolling resistance while preserving aquaplaning resistance throughout the service life.

Inventive Principle:
Principle #1Segmentation

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 variable tread pattern maintains consistent wet performance by increasing water flow through the tire, reducing slippage and aquaplaning resistance throughout the tire's life, even as the tread wears down.

Implementation Method 1

water flow through the grooves, carrying the water through the footprint

Methodology Applied
Scientific EffectWater flow through grooves:

Implementation Method 2

The grooves provide means for water evacuation and form the biting edges of the tread elements

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP1935671B1Pneumatic tire
Publication Date: 2011.05.25 THE GOODYEAR TIRE & RUBBER CO
  • EP1935671B1 patent drawingFigure 1
  • EP1935671B1 patent drawingFigure 1A~2A
  • EP1935671B1 patent drawingFigure 2

AI summary

A pneumatic tire (10) has a tread (12) having a plurality of grooves (16) creating an initial tread configuration. The grooves and the tread elements formed thereby result in a tread have a net-to-gross ratio in the range of greater than 60%. Due to variations in the depths and variations in the heights and formations of the tread elements, after the tread has been worn, the tread has a net-to-gross ratio in the range of less than 60%.