Resin Tire Frame Weather Resistance via Covering Layer

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Solution Overview

Problem

Tire frame members formed from resin materials face challenges in enhancing weather resistance while maintaining design flexibility, as existing configurations require material changes to improve weather resistance, limiting design freedom.

Innovation Solution

A tire design featuring a resin material frame member with a bead portion, tread member, tire frame step portion, and a covering layer that spans from the bead portion to the tire frame step portion, ensuring the frame member's surface is not exposed and enhancing weather resistance without reducing design flexibility, using a resin or rubber covering layer to protect the outer face and prevent material flow during molding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the tire frame member is formed from a resin material, then weight reduction and ease of recycling are achieved, but weather resistance is insufficient when the frame member is exposed

Engineering Contradiction:

Improveweather resistanceVSAvoidexposure to weather

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A covering layer is introduced as an intermediary element between the resin material tire frame member and the external environment. This covering layer protects the frame member from weather exposure while allowing the resin material to maintain its weight reduction and recyclability advantages. The covering layer can be formed from rubber or resin material and spans from the bead portion to the tire frame step portion.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If the tire frame member surface is covered to improve weather resistance, then design freedom is reduced

Engineering Contradiction:

Improveweather resistanceVSAvoiddesign freedom

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The covering layer is applied selectively to specific regions of the tire frame member - spanning from the bead portion to the tire frame step portion - rather than covering the entire structure. This localized application provides weather protection where needed while leaving other areas of the frame member exposed, thereby maintaining design freedom and flexibility for the overall tire structure.

Inventive Principle:

Principle #3Local quality

3Manufacturing precision

If the covering layer material flows during molding, then the end portions of the covering layer cannot be appropriately formed

Engineering Contradiction:

Improveforming precision of covering layer end portionsVSAvoidmaterial flow and protrusion

Core Design Contradiction:

Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The tire frame step portion is formed in advance on the tire frame member before the covering layer is applied. This pre-formed step portion serves as a barrier that prevents the covering layer material from flowing beyond the desired position during molding. By preparing this structural feature beforehand, the patent ensures that the covering layer end portions are appropriately formed without material protrusion.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS9937757B2Tire

Publication Date: 2018.04.10 BRIDGESTONE CORP

AI summary

Tire frame step portions 18 are formed to a tire frame member 17. The tire frame step portions 18 are formed further toward the tire equatorial plane side than tire axial direction end portions 30A of a tread member 30. Covering layers 24 are formed at the outside of the tire frame member 17 so as to span from bead portions to the tire frame step portions 18.