Tire Summit Flat Equilibrium Curve Design

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Solution Overview

Problem

Conventional tire designs with three-ply membrane models result in significant curvature at the summit, leading to 'droop' in summit belts, which limits tire width, causes uneven wear, and affects contact pressure distribution, making it difficult to achieve wider tires with improved performance.

Innovation Solution

A tire design featuring circumferentially-oriented reinforcement belts with a flat equilibrium curve throughout the summit, reducing belt tension and eliminating droop, allowing for wider tire construction with improved tread wear and contact pressure distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If conventional three-ply membrane model equilibrium curves are used with significant summit curvature, then the carcass and belts naturally follow the curved shape, but this causes droop in summit belts which limits tire width and causes uneven wear

Engineering Contradiction:

Improvesummit curvatureVSAvoidtire width

Core Design Contradiction:

ShapeVSEase of operation

Solution Approach 1:

The patent inverts the conventional approach by using a flat equilibrium curve instead of a curved one in the summit region. This inversion eliminates the droop effect that occurs with curved equilibrium curves, allowing belts to maintain a straighter profile and enabling wider tire construction without the limitations imposed by belt droop.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent changes the geometric parameter of the equilibrium curve from curved to flat in the summit region. This parameter change fundamentally alters the stress distribution and belt behavior, reducing droop and enabling wider tire designs while maintaining structural integrity.

Inventive Principle:

Principle #35Parameter changes

2Stability of the object's composition

If conventional curved equilibrium curves are used, then the tire structure follows natural curvature, but this results in different roiling radii across the tread width causing uneven wear rates

Engineering Contradiction:

Improvestructural integrityVSAvoidtread wear uniformity

Core Design Contradiction:

Stability of the object's compositionVSReliability

Solution Approach 1:

The patent inverts the conventional curved equilibrium curve approach by implementing a flat equilibrium curve in the summit region. This inversion equalizes the roiling radii across the tread width, ensuring more uniform contact pressure distribution and consistent wear rates from center to shoulder regions.

Inventive Principle:

Principle #13The other way round (Inversion)

3Ease of manufacture

If summit belts are designed to follow curved equilibrium curves, then the belt structure is naturally formed, but this creates high belt tension that limits the overall tire width

Engineering Contradiction:

Improvebelt constructionVSAvoidtire width

Core Design Contradiction:

Ease of manufactureVSLength of stationary object

Solution Approach 1:

The patent inverts the conventional approach by using a flat equilibrium curve instead of a curved one, which reduces the tension experienced by summit belts. This tension reduction allows for wider tire construction while maintaining belt structural integrity and ease of manufacture.

Inventive Principle:

Principle #13The other way round (Inversion)

Data Source

PatentEP2804769B1Tire construction with flattened summit and circumferential reinforcement

Publication Date: 2020.04.08 MICHELIN & CO (CIE GEN DES ESTAB MICHELIN)

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Figure 3A~3B

AI summary

A tire constructed with a plurality of reinforcement belts is provided. At least one of the reinforcement belts extends along the axial width of the tire summit and is constructed according to an equilibrium curve that is flat throughout the summit. The reinforcement belts include cable reinforcements that are substantially parallel to the equatorial plane. Substantial reductions in the tension experienced by the cables can be achieved to provide, as a result, improvements in e.g., tread wear.