Tire Side Part Turbulent Flow Ridges Heat Management

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Solution Overview

Problem

Conventional tires face challenges in reducing temperature in the tire side portion, particularly in run-flat tires, which affects durability and rolling resistance, with existing solutions either increasing weight, deteriorating normal-running performance, or failing to efficiently manage heat radiation due to the use of rubber compositions with low thermal conductivity.

Innovation Solution

The implementation of turbulent flow-creating ridges on the tire surface and a rubber composition containing a modified conjugated diene-based polymer that interacts well with carbon black, enhancing heat radiation and reducing rolling resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a reinforcing member is provided to reduce tire distortion and prevent temperature increase, then durability is improved, but tire weight increases and normal-running performance deteriorates

Engineering Contradiction:
ImprovedurabilityVSAvoidtire weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The invention extracts the heat-generating function from the reinforcing member by removing the metal mesh and using only the rubber layer with heat radiation-promoting structures. This eliminates the weight penalty of metal components while maintaining the heat management function through external turbulent flow creation.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention introduces air flow as an intermediary medium to transfer heat from the tire surface to the environment. The turbulent flow-creating structures mediate between the heat source (tire) and the cooling medium (air), enabling efficient heat dissipation without adding heavy reinforcing materials.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Temperature

If the surface area of the tire is increased to accelerate heat radiation, then heat dissipation is improved, but rolling resistance increases due to rubber material with low thermal conductivity

Engineering Contradiction:
Improveheat radiation efficiencyVSAvoidrolling resistance
Core Design Contradiction:
TemperatureVSLoss of energy

Solution Approach 1:

The invention uses turbulent flow (a form of chaotic fluid motion) to enhance heat transfer from the tire surface. The turbulent eddies and mixing in the air flow create efficient thermal convection, dramatically improving heat radiation without requiring increased tire surface area or changes to the rubber composition.

Inventive Principle:
Principle #18Mechanical vibration

3Reliability

If rubber composition is modified to increase elastic modulus and suppress reduction at high temperatures, then run-flat durability is improved, but rolling resistance at normal running remarkably deteriorates

Engineering Contradiction:
Improverun-flat durabilityVSAvoidrolling resistance
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The invention separates the heat management function from the structural reinforcement function. The rubber layer maintains its original composition for normal running performance, while heat dissipation is achieved through externally applied turbulent flow-creating structures on the tire surface.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention changes the flow regime parameter of the air surrounding the tire from laminar to turbulent flow. This parameter change dramatically enhances heat transfer coefficients, allowing efficient heat dissipation without modifying the rubber composition or increasing tire temperature resistance.

Inventive Principle:
Principle #35Parameter changes

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 approach effectively reduces tire temperature, improves durability during run-flat conditions, and maintains low rolling resistance during normal running by combining efficient heat radiation with a rubber composition that suppresses heat generation.

Implementation Method 1

providing turbulent flow-creating ridges which extend from an inner circumference side to an outer circumference side, at intervals in a circumferential direction of a tire

Methodology Applied
Scientific EffectTurbulent flow: Turbulence

Implementation Method 2

a technology for accelerating the heat radiation of the above-mentioned pneumatic tire

Methodology Applied
Scientific EffectHeat radiation: Thermal Radiation

Implementation Method 3

a rubber composition obtained by compounding 100 parts by mass of rubber components containing 10 mass% or more of a modified conjugated diene-based polymer, which is obtained by introducing a primary amino group or a precursor capable of producing a primary amino group through hydrolysis to a terminal of a conjugated diene-based polymer through a modification reaction between the terminal and an alkoxysilane compound having the primary amino group or the precursor capable of producing a primary amino group through hydrolysis

Methodology Applied
Scientific EffectAdsorption: Adsorption

Data Source

PatentEP2425990B1tire
Publication Date: 2014.12.24 BRIDGESTONE CORP
  • EP2425990B1 patent drawingFigure 1
  • EP2425990B1 patent drawingFigure 2
  • EP2425990B1 patent drawingFigure 3~4

AI summary

Disclosed is a pneumatic tire, in which turbulent flow-creating ridges extending from the inner circumference side to the outer circumference side are formed at intervals in the tire circumference direction on the tire surface of a tire side part, wherein: said turbulent flow-creating ridges have edge parts, as viewed in the sectional shape cut in the radial direction; the front wall angle, which is made between the front wall faces of the turbulent flow creating ridges to be hit by an air flow and the tire surface, ranges from 70o to 110o; and, as a side-reinforcing rubber constituting said tire side part, a rubber composition prepared by blending 100 parts by mass of a rubber component containing 10 mass% or more of a modified conjugated diene polymer, which is obtained by conducting a modification reaction between a terminus of a conjugated diene polymer and an alkoxysilane compound having a primary amino group or a precursor capable of forming a primary amino group through hydrolysis to thereby introduce the primary amino group or the precursor capable of forming a primary amino group through hydrolysis to said terminus, and further adding a fusion accelerator to the modification reaction system in the course of the modification reaction or after the completion thereof, with 10 to 100 parts by mass of carbon black having a nitrogen adsorption specific surface area of 20 to 90 m2/g. Thus, it is possible to provide a durability-improvable tire, in which the temperature inside the tire side part can be lowered due to efficient heat radiation, and the durability during run-flat traveling and the rolling resistance during normal traveling, as the rubber composition, can be simultaneously improved.