Removable Run-Flat Load Support Body for Pneumatic Tires

Solution Overview

Problem

Pneumatic tires with side reinforcing layers for run-flat capabilities suffer from increased rolling resistance and reduced riding comfort, especially in high aspect ratio tires, and are not reusable after damage, leading to unnecessary tire replacement.

Innovation Solution

A pneumatic tire design featuring a load support body extending along the tire circumferential direction on the inner sidewall portion, removably mounted via a mechanical engagement device such as surface fasteners, which minimizes contact area and allows for stable run-flat travel while enabling tire reusability by exchanging the load support body.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a side reinforcing layer constituted by rubber composition is integrally formed on the inner side of the sidewall portion, then run-flat traveling is enabled, but rolling resistance and riding comfort deteriorate significantly

Engineering Contradiction:

Improverun-flat capabilityVSAvoidrolling resistance

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The load support function is segmented into a separate removable load support body that can be independently attached to the sidewall inner surface. This separates the run-flat capability from the tire's integral structure, allowing the tire to maintain its original soft sidewall characteristics for low rolling resistance while adding rigid support only when needed for run-flat operation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The load support body is designed to be removably mounted rather than permanently fixed, allowing dynamic adjustment of the tire's mechanical properties. During normal operation, the load support body can be removed to maintain low rolling resistance, while during puncture events, it can be attached to enable run-flat capability.

Inventive Principle:

Principle #15Dynamics

2Reliability

If a side reinforcing layer is integrally formed on the inner side of the sidewall portion, then run-flat traveling is enabled, but the tire cannot be reused after the layer is damaged

Engineering Contradiction:

Improverun-flat capabilityVSAvoidreusability after damage

Core Design Contradiction:

ReliabilityVSEase of repair

Solution Approach 1:

The load support function is segmented into a separate removable load support body that can be independently attached to the sidewall inner surface. This separates the run-flat capability from the tire's integral structure, allowing the tire to maintain its original soft sidewall characteristics for low rolling resistance while adding rigid support only when needed for run-flat operation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The load support body is designed as a disposable component that can be discarded after damage during run-flat traveling, while the expensive tire casing is recovered and reused. The removable mounting allows the intact tire to be retained and the only replacement needed is the relatively inexpensive load support body.

Inventive Principle:

Principle #34Discarding and recovering

3Reliability

If the volume of the side reinforcing layer is increased to enable run-flat traveling in high aspect ratio tires, then run-flat capability is improved, but deterioration of rolling resistance and riding comfort becomes significant

Engineering Contradiction:

Improverun-flat capability in high aspect ratio tiresVSAvoidriding comfort

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The load support function is segmented into a separate removable load support body that can be independently attached to the sidewall inner surface. This separates the run-flat capability from the tire's integral structure, allowing the tire to maintain its original soft sidewall characteristics for low rolling resistance while adding rigid support only when needed for run-flat operation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The load support body provides localized rigid support only at the sidewall inner surface where needed for run-flat operation, while the rest of the tire structure remains unchanged. This localized reinforcement enables run-flat capability in high aspect ratio tires without requiring global structural changes that would compromise riding comfort.

Inventive Principle:

Principle #3Local quality

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 solution effectively suppresses rolling resistance and maintains riding comfort during normal travel while enabling stable run-flat travel and reusability of the tire, even in high aspect ratio tires, by using a removable load support body with a mechanical engagement device.

Implementation Method 1

the load support body is removably mounted to an inner surface of the sidewall portion via a mechanical engagement device

Methodology Applied

Scientific EffectMechanical Fastener: Mechanical Fastener

Data Source

PatentUS11554616B2Pneumatic tire with removably mounted run-flat load support bodies

Publication Date: 2023.01.17 THE YOKOHAMA RUBBER CO LTD

AI summary

In a pneumatic tire including an annular tread portion extending in a tire circumferential direction, a pair of sidewall portions disposed on both sides of the tread portion, and a pair of bead portions disposed on an inner side of the sidewall portions in a tire radial direction, a load support body is disposed extending along the tire circumferential direction on an inner side of each of the sidewall portions, and the load support body is removably mounted to an inner surface of the sidewall portion via a mechanical engagement device.