Small-Diameter Non-Pneumatic Tire Resin Modulus for Comfort and Durability

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Solution Overview

Problem

Existing non-pneumatic tires face challenges in achieving both ride comfort and durability, particularly in small diameter sizes.

Innovation Solution

A non-pneumatic tire design using a resin composition for the skeletal member with specific bending modulus ranges at different temperatures to maintain optimal flexibility and strength, ensuring ride comfort and durability across varying temperatures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If pneumatic tires are used, then rolling resistance is reduced and fuel economy is improved, but safety is compromised due to inability to provide sufficient friction force when deflated

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

Solution Approach 1:

The patent changes the fundamental parameter of tire structure from pneumatic (air-filled) to non-pneumatic (solid foam structure), enabling the tire to maintain safety functionality even when completely deflated or damaged, while preserving acceptable rolling resistance through optimized foam density and tread design

Inventive Principle:
Principle #35Parameter changes

2Reliability

If tire pressure monitoring systems are installed to detect underinflation, then safety is improved, but device complexity and cost increase

Engineering Contradiction:
ImprovesafetyVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The non-pneumatic tire structure inherently provides safety functionality without requiring external monitoring systems. The solid foam construction automatically maintains structural integrity and provides friction force even when damaged, making the tire self-sufficient and eliminating the need for complex pressure monitoring equipment

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent removes the vulnerable pneumatic element from the tire system, eliminating the need for pressure monitoring. By extracting the air chamber and replacing it with a solid foam structure, the system eliminates the entire class of pressure-related safety issues and monitoring requirements

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of manufacture

If pneumatic tires are used, then manufacturing cost is reduced, but environmental harm increases due to run-flat capabilities and material usage

Engineering Contradiction:
Improvemanufacturing costVSAvoidenvironmental harm
Core Design Contradiction:
Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The patent changes the material parameter from traditional rubber compounds to foam-based materials, which reduces overall material consumption while maintaining structural functionality. This parameter change enables run-flat capabilities without requiring additional reinforcement materials, thereby reducing environmental harm

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

The tire achieves balanced ride comfort and durability over a wide temperature range, even in small diameters, by utilizing a resin composition with controlled bending modulus values.

Implementation Method 1

the foam material is sufficiently resilient to enable the non-pneumatic tire to deform and thereby provide sufficient friction force between the non-pneumatic tire and a road surface

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

the foam material has sufficient damping characteristics

Methodology Applied
Scientific EffectHysteresis: Hysteresis

Data Source

PatentEP4338981B1Non-pneumatic tire
Publication Date: 2026.04.08 BRIDGESTONE CORP
  • EP4338981B1 patent drawingFigure 1

AI summary

The problem of this disclosure is to provide a non-pneumatic tire that achieves both ride comfort and durability, even in a small diameter size. The solution is a non-pneumatic tire (1) using a resin composition as a skeletal member, wherein the resin composition has a bending modulus of elasticity of 247 MPa or less at -20°C in accordance with ISO 178 and a bending modulus of elasticity of 32 MPa or more at 60°C in accordance with ISO 178, and a tire diameter D in the tire radial direction is 35 cm or less.