Polyurethane Foam Tire Heat Insulation

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Solution Overview

Problem

Existing methods for improving the heat-insulating properties of pneumatic vehicle tires to reduce rolling resistance often require additional adhesive layers, which can increase rolling resistance and lead to component failures due to stiffness differences.

Innovation Solution

Applying a thixotropic or liquid polyurethane system directly to the outside of the tire, which foams and hardens to form thermal insulation layers on the tire rim and tread areas without the need for an additional adhesive layer, effectively dissipating heat through the tire's outer surface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an adhesive layer is used to bond foam material to the tire surface, then the foam material can be securely attached, but rolling resistance increases and component failure risk increases due to stiffness differences

Engineering Contradiction:
Improveattachment reliabilityVSAvoidrolling resistance
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The adhesive layer and foam insulation layer are merged into a single integrated component. The polyurethane system serves dual functions: as the bonding agent and as the thermal insulation material, eliminating the interface between adhesive and foam that causes stiffness mismatches and energy loss.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The adhesive layer is extracted as a separate function and integrated into the foam material itself. The polyurethane system provides both adhesion and insulation properties, removing the need for a distinct adhesive layer that would otherwise contribute to rolling resistance and potential failure points.

Inventive Principle:
Principle #2Taking out (Extraction)

2Strength

If a separate adhesive layer is applied between the foam and tire surface, then bonding is achieved, but the structure becomes more complex and prone to cracking

Engineering Contradiction:
Improvebonding strengthVSAvoidlayer structure complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The adhesive function and insulation function are combined into a single polyurethane layer, reducing the multi-layer structure to a unified component that is less prone to interfacial cracking and structural complexity.

Inventive Principle:
Principle #5Merging (Combining)

3Temperature

If foam material is applied to the tire exterior, then heat dissipation to the environment is reduced, but the application process becomes more complex

Engineering Contradiction:
Improveheat dissipationVSAvoidapplication simplicity
Core Design Contradiction:
TemperatureVSEase of manufacture

Solution Approach 1:

The polyurethane system's physical state is changed from requiring pre-formed foam blocks to a liquid or thixotropic state that can be directly applied. This parameter change enables simple application methods while maintaining the thermal insulation function, as the material can be sprayed, brushed, or rolled onto the tire surface.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The polyurethane material undergoes phase transition from liquid/thixotropic state during application to solid foam after curing. This allows the material to be applied in a fluid state for ease of manufacture, then transforms into the desired solid insulation structure, simplifying the application process while maintaining thermal performance.

Inventive Principle:
Principle #36Phase transitions

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 method reduces tire rolling resistance by dissipating heat energy to the environment, eliminating the drawbacks of additional adhesive layers and enhancing the tire's heat-insulating properties without component failure risks.

Implementation Method 1

a thixotropic or liquid, one- or two-component polyurethane system is applied directly to the outside of the vehicle pneumatic tire, foaming up immediately upon application or with a time delay

Methodology Applied
Scientific EffectFoaming: Foam

Implementation Method 2

forming at least one heat insulation layer... dissipating heat through the tire's outer surface

Methodology Applied
Scientific EffectThermal Insulation: Thermal Insulation

Implementation Method 3

Due to the airflow across the tire's exterior, a significant amount of heat energy is dissipated to the environment via the tire's surface

Methodology Applied
Scientific EffectHeat dissipation: Convection

Data Source

PatentEP3272556B1Pneumatic vehicle tyre with polyurethane foam as a heat isolation layer and method for producing at least one heat isolation layer made of polyurethane foam
Publication Date: 2019.05.22 CONTINENTAL REIFEN DEUTSCHLAND GMBH
  • EP3272556B1 patent drawingFigure 1

AI summary

Vehicle pneumatic tire which can be mounted on a tire rim (2) and which has a profiled tread (3) with grooves (4), sidewalls (9) and bead areas (7) as well as polyurethane foam as thermal insulation on its surface. The polyurethane foam is applied to the outside of the vehicle pneumatic tire (1), with the outer surfaces of the bead areas (7) and the driving surface of the tread (3) that come into contact with the tire rim (2) being left out.