Conductive Surface Cord Layout for Low-Resistance Pneumatic Tires

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Solution Overview

Problem

Low conductive rubber used in low rolling resistance tires deteriorates the conductivity of the tire, limiting the effectiveness of static electricity discharge to the ground.

Innovation Solution

Incorporating a surface cord with a conductive coating on the carcass of the tire, disposed from one bead to the other via the tread, to form a conductive path between the vehicle and the ground, enhancing the tire's overall conductivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If low conductive rubber is used to reduce rolling resistance, then fuel efficiency is improved, but tire conductivity deteriorates

Engineering Contradiction:
Improverolling resistanceVSAvoidtire conductivity
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The conductive function is segmented from the rubber material itself and assigned to a separate conductive cord component. The carcass is divided into inner and outer layers with conductive cords embedded in specific positions, allowing the rubber to focus on low rolling resistance while dedicated conductive elements handle electricity discharge.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The tire combines low conductive rubber material with embedded conductive cords to create a composite structure. This allows the bulk rubber to maintain low rolling resistance properties while the conductive cord additives provide the necessary electrical conductivity pathway.

Inventive Principle:
Principle #40Composite materials

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

This configuration ensures effective discharge of static electricity to the ground, maintaining low rolling resistance while improving tire conductivity, preventing issues like radio noise and passenger safety during vehicle entry and exit.

Implementation Method 1

a surface cord 80 having conductivity is disposed on an outer surface 40a of the carcass 40

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP3785948B1tire
Publication Date: 2023.11.08 BRIDGESTONE CORP
  • EP3785948B1 patent drawingFigure 1
  • EP3785948B1 patent drawingFigure 2
  • EP3785948B1 patent drawingFigure 3~4

AI summary

A pneumatic tire 10 includes a surface cord 80 disposed on at least one of an outer surface 40a , which is a surface of a carcass 40 at a tire outer side, and an inner surface 40b, which is a surface of the carcass 40 at a tire inner side. The surface cord 80 has conductivity and is disposed along a tire width direction from at least a region adjoining a bead 60 to a tread 20. A plurality of the surface cords 80 is disposed with a predetermined interval in a tire circumferential direction.