Tire Sidewall Conductive Path for Static Charge Dissipation

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Solution Overview

Problem

Conventional tires with high silica content accumulate static charge, leading to undesirable static electricity issues during vehicle operation, and existing solutions either compromise on wear resistance or conductivity.

Innovation Solution

A tire design featuring a conductive path in the sidewall region, including a body ply, circumferential belt, cap ply, tread, undertread, and sidewall antennas with specific resistivity values, allowing for efficient charge dissipation through a continuous conductive path from the beads to the ground.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If high silica content is used in tire rubber, then rolling resistance is reduced and fuel efficiency is improved, but static charge accumulates leading to electrical conductivity deterioration

Engineering Contradiction:
Improvefuel efficiencyVSAvoidelectrical conductivity
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The tire is divided into multiple rubber layers with different silica contents. The inner sidewall layer uses high silica content (5-50 phr) for fuel efficiency, while the outer sidewall layer uses low silica content (0-20 phr) to maintain electrical conductivity. This segmentation allows each layer to optimize its properties independently, resolving the contradiction between fuel efficiency and conductivity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the tire are assigned different material compositions tailored to their specific functional requirements. The inner sidewall layer is designed with high silica for energy efficiency where conductivity is less critical, while the outer sidewall layer is designed with low silica where maintaining conductivity is paramount. This local differentiation resolves the global contradiction by optimizing each location's properties.

Inventive Principle:
Principle #3Local quality

2Use of energy by moving object

If silica content is increased to reduce rolling resistance, then fuel efficiency improves, but wear resistance deteriorates

Engineering Contradiction:
Improvefuel efficiencyVSAvoidwear resistance
Core Design Contradiction:
Use of energy by moving objectVSStrength

Solution Approach 1:

The tire structure is segmented into inner and outer sidewall layers with different silica contents. The inner layer uses high silica (5-50 phr) for fuel efficiency, while the outer layer uses low silica (0-20 phr) for wear resistance. This segmentation allows simultaneous optimization of both fuel efficiency and wear resistance in different locations.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The outer sidewall layer is specifically designed with low silica content to maintain wear resistance where the tire contacts the environment, while the inner layer uses high silica for fuel efficiency. This local quality differentiation resolves the contradiction between fuel efficiency and wear resistance.

Inventive Principle:
Principle #3Local quality

3Reliability

If a conductive path is added to the sidewall, then static charge dissipation is improved, but device complexity increases

Engineering Contradiction:
Improvestatic charge dissipationVSAvoidtire structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The conductive path function is merged into the outer sidewall layer itself by using low silica rubber composition that inherently provides conductivity. Rather than adding a separate conductive component, the sidewall layer is designed to perform both structural and conductive functions, reducing overall device complexity while maintaining charge dissipation capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The outer sidewall layer serves multiple functions: it provides structural integrity, environmental protection, and electrical conductivity for charge dissipation. This multi-functionality eliminates the need for separate dedicated conductive components, thereby reducing device complexity while achieving reliable static charge dissipation.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 dissipates static charge without compromising wear resistance or conductivity, ensuring safe and efficient vehicle operation by providing a continuous conductive path for electric charge dissipation.

Implementation Method 1

a conductive path in the sidewall region, including a body ply, circumferential belt, cap ply, tread, undertread, and sidewall antennas with specific resistivity values, allowing for efficient charge dissipation through a continuous conductive path from the beads to the ground

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP3860866B1Tire having a conductive path in a sidewall
Publication Date: 2024.05.15 BRIDGESTONE AMERICAS TIRE OPERATIONS LLC
  • EP3860866B1 patent drawingFigure 1
  • EP3860866B1 patent drawingFigure 2
  • EP3860866B1 patent drawingFigure 3

AI summary

A tire includes a circumferential tread disposed in a crown region of the tire and an undertread disposed below the circumferential tread. The tire also has a pair of bead regions, including a first bead region and a second bead region, and a body ply extending from the first bead region to the second bead region. The tire further has a pair of sidewalls, including a first sidewall extending between the first bead region and the circumferential tread and a second sidewall extending between the second bead region and the circumferential tread. The tire also has a sidewall antenna adjacent to the first sidewall. The sidewall antenna has a first end contacting the undertread and a second end contacting the body ply.