Bead Core Non-Linear Interface Resilience

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Solution Overview

Problem

The durability of bead cores with a strip member coated with a resin is compromised when subjected to large lateral forces, as the interface between adjacent resin coatings can peel off, leading to reduced durability.

Innovation Solution

A bead core design featuring an annular body with a non-linear interface between stacked strip members, where the strip members are wound and coated with a resin, enhancing the joining force and cross-sectional secondary moment, and can be manufactured using hot plate welding or adhesives.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a strip member comprising one or more bead wires coated with a coating resin is wound and stacked to form an annular body, then productivity is improved and weight is reduced, but the interface between adjacent stacks peels off under large lateral forces, reducing durability

Engineering Contradiction:

ImproveproductivityVSAvoiddurability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The interface between adjacent stacks is designed to be non-linear (curved) rather than straight, increasing the contact area and interlocking between stacks. This curvature prevents peeling under lateral forces while maintaining the stacked construction method for improved productivity.

Inventive Principle:

Principle #14Spheroidality (Curvature)

2Ease of manufacture

If the interface between adjacent stacks is linear, then manufacturing is simpler, but the joining force between stacks is insufficient and peeling occurs under lateral forces

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidjoining force

Core Design Contradiction:

Ease of manufactureVSStrength

Solution Approach 1:

Inventive Principle:

Principle #14Spheroidality (Curvature)

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 non-linear interface increases the joined area and joining force between stacks, improving durability and resistance to deformation under lateral forces, while also stabilizing manufacturing accuracy and quality.

Implementation Method 1

adjacent stacks of coating resins can be joined to each other, for example, by welding or bonding

Methodology Applied

Scientific EffectHeating: Heating

Implementation Method 2

a strip member comprising one or more bead wires coated with a coating resin is wound and stacked

Methodology Applied

Scientific EffectMelting: Melting

Data Source

PatentEP3643530B1Bead core, production method therefor, and pneumatic tire

Publication Date: 2023.03.08 BRIDGESTONE CORP

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AI summary

A bead core of the present disclosure is a bead core comprising an annular body in which a strip member comprising one or more bead wires coated with a coating resin is wound and stacked, and in an axial cross section of the annular body, an interface between stacks adjacent to each other is non-linear. A manufacturing method of a bead core of the present disclosure comprises an annular body forming step of winding and stacking a strip member comprising one or more bead wires coated with a coating resin to form an annular body, and the strip member has a side that comes in contact with an adjacent stack in the annular body forming step and that is non-linear in a cross section orthogonal to an extending direction of the strip member.