Tire Bead Fillers Segmentation for Durability

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Solution Overview

Problem

Cyclical loading and repeated stresses at the junction between the tire body ply and the bead filler lead to durability concerns in tires, particularly due to friction and component shifting.

Innovation Solution

The tire design incorporates first and second bead portions with main and auxiliary bead fillers, where the carcass ply wraps around the bead portions, and the auxiliary bead fillers are positioned to sandwich the turn-up portions of the carcass ply, providing additional support and durability by contacting both the sidewalls and the main bead fillers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a single bead filler is used in conventional tire design, then the structure is simple and easy to manufacture, but the junction between the body ply and bead filler suffers from durability issues due to cyclical loading and repeated stresses

Engineering Contradiction:

Improvedurability at bead filler junctionVSAvoidbead filler structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The bead filler is divided into two separate components: a main bead filler and an auxiliary bead filler. The main bead filler is positioned within the bead portion, while the auxiliary bead filler is positioned axially outside the main bead filler and body ply end. This segmentation allows each filler to serve specific functions, with the auxiliary filler providing additional support at the critical junction area where the body ply meets the bead filler, thereby improving durability without requiring a completely new structural approach

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The auxiliary bead filler acts as an intermediary element between the main bead filler and the body ply turn-up portions. It is positioned to contact both the main bead filler and the turn-up portions, creating a transitional zone that distributes stresses and reduces friction at the junction. This intermediary structure mitigates the harmful effects of cyclical loading and repeated stresses that would otherwise concentrate at the single bead filler junction

Inventive Principle:

Principle #24Intermediary (Mediator)

2Strength

If the carcass ply is wrapped tightly around the bead filler to improve structural integrity, then strength is improved, but friction and component shifting increase under cyclical loading

Engineering Contradiction:

Improvestructural integrity of bead regionVSAvoidfriction and component shifting

Core Design Contradiction:

StrengthVSObject-generated harmful factors

Solution Approach 1:

The bead filler system is segmented into main and auxiliary fillers, allowing the carcass ply to wrap around the main bead filler while the auxiliary bead filler provides additional support at the junction area. This segmentation enables the ply to maintain structural integrity through tight wrapping while the auxiliary filler reduces friction and prevents shifting by providing a stable interface at the critical junction zone

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The auxiliary bead filler serves as an intermediary that reduces friction between the carcass ply turn-up portions and the main bead filler. By positioning the auxiliary filler to contact both elements, it creates a low-friction interface that prevents component shifting under cyclical loading while maintaining the structural integrity provided by the tight wrapping of the carcass ply

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If the auxiliary bead filler is positioned to sandwich the turn-up portions, then durability is improved through stress distribution, but manufacturing precision requirements increase

Engineering Contradiction:

Improvedurability under cyclical loadingVSAvoidpositioning of auxiliary bead filler

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The auxiliary bead filler is positioned specifically at the critical junction area where the body ply turn-up portions meet the main bead filler, rather than uniformly distributing material throughout the bead region. This local quality approach concentrates the durability enhancement exactly where the stresses and friction are most problematic, improving reliability without requiring complex manufacturing processes across the entire bead structure

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The invention changes the positional parameters of the bead filler system by introducing an auxiliary filler at a specific axial location outside the main bead filler. This parameter change creates a sandwich configuration that distributes stresses effectively, while the clear definition of positional relationships (axially outside, radially positioned) provides manufacturing guidance that reduces precision requirements

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS10583696B2Tire with bead regions having multiple bead fillers

Publication Date: 2020.03.10 BRIDGESTONE AMERICAS TIRE OPERATIONS LLC

AI summary

A tire includes a bead portion with a bead core having a main bead filler and an auxiliary bead filler, and a carcass ply wrapped around a portion of the main bead filler. An end of the carcass ply is located axially outside the main bead filler and radially below an apex of the main bead filler. The auxiliary bead filler is located axially outside the carcass ply end, with an apex of the auxiliary bead filler being located above an apex of the main bead filler.