Multi-Layer Bead Filler Structure for Lower Rolling Resistance Tires

Solution Overview

Problem

Existing pneumatic tires face issues with insufficient durability and increased weight and rolling resistance due to inadequate deformation control in the bead area, which is addressed by developing a tire with a bead filler composed of multiple rubber layers to reduce weight and improve rolling resistance.

Innovation Solution

The tire features a second bead filler with multiple rubber layers of varying hardness and modulus, strategically positioned between the turned-up carcass and the rim, to control deformation and reduce weight and rolling resistance, while the first bead filler surrounds the carcass to attenuate external shocks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a double bead structure is used to reinforce the bead, then durability is improved, but weight and rolling resistance increase

Engineering Contradiction:

Improvebead durabilityVSAvoidtire weight

Core Design Contradiction:

ReliabilityVSWeight of moving object

Solution Approach 1:

The bead filler is divided into multiple rubber layers with different hardness values. The first bead filler layer has a first hardness value, the second bead filler layer has a second hardness value different from the first, creating a segmented structure that provides reinforcement while controlling weight and rolling resistance through optimized layer distribution

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the bead filler are assigned different rubber layer configurations and hardness values based on local deformation requirements. The multiple layers are positioned at specific locations within the bead region to provide targeted reinforcement where needed while minimizing weight in less critical areas

Inventive Principle:

Principle #3Local quality

2Reliability

If a double bead structure is used to reinforce the bead, then durability is improved, but rolling resistance increases

Engineering Contradiction:

Improvebead durabilityVSAvoidrolling resistance

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The bead filler is divided into multiple rubber layers with different hardness values. The first bead filler layer has a first hardness value, the second bead filler layer has a second hardness value different from the first, creating a segmented structure that provides reinforcement while controlling weight and rolling resistance through optimized layer distribution

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The hardness parameter of rubber layers is varied across different bead filler layers. By changing the hardness parameter (creating layers with different hardness values), the invention optimizes the balance between durability and rolling resistance, allowing softer layers to reduce energy loss while harder layers provide structural support

Inventive Principle:

Principle #35Parameter changes

3Weight of moving object

If the bead filler is formed with multiple rubber layers, then weight is reduced and rolling resistance is improved, but deformation control at respective positions becomes complex

Engineering Contradiction:

Improvetire weightVSAvoidbead filler structure complexity

Core Design Contradiction:

Weight of moving objectVSDevice complexity

Solution Approach 1:

The bead filler is divided into multiple rubber layers with different hardness values. The first bead filler layer has a first hardness value, the second bead filler layer has a second hardness value different from the first, creating a segmented structure that provides reinforcement while controlling weight and rolling resistance through optimized layer distribution

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the bead filler are assigned different rubber layer configurations and hardness values based on local deformation requirements. The multiple layers are positioned at specific locations within the bead region to provide targeted reinforcement where needed while minimizing weight in less critical areas

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

This configuration effectively reduces weight, improves rolling resistance, and minimizes compressive and shear deformation of the bead part by optimizing the placement and properties of the rubber layers, enhancing the tire's durability and performance.

Implementation Method 1

a second bead filler disposed between an outer side of the turned-up carcass, a side wall, and the rim, wherein the second bead filler comprises multiple rubber layers composed of different kinds of rubber material layers

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentEP3725565B1Pneumatic tire with bead filler applied with multiple rubber layer

Publication Date: 2023.10.18 HANKOOK TIRE & TECHNOLOGY CO LTD

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AI summary

The present invention relates to a pneumatic tire with a bead filler applied with multiple rubber layers, in more detail, a pneumatic tire having a side wall curved at both sides of a tread that is a thick rubber layer that comes in direct contact with a road surface, a bead core seated on a rim of a vehicle, and a bead part having a difference of rubber hardness. The pneumatic tire includes a carcass that is an internal frame of the tire and is provided to be turned up around the bead core of the bead part, in which the bead part includes: a first bead filler that is surrounded by the carcass and a turned-up carcass inside the tire; and a second bead filler that is disposed between the outer side of the turned-up carcass, the side wall, and the rim, and is applied with multiple rubber layers composed of different kinds of rubber layers to reduce weight and improve rolling resistance.