Resin Tire Frame Thickness Layout for Ride and Handling Balance

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Solution Overview

Problem

Conventional tire designs that increase wall thickness for improved handling performance also increase vertical stiffness and resin material usage, leading to higher costs and potential ride quality issues.

Innovation Solution

The tire frame member's thickness decreases from T1 to T2 on the tire radial direction outer side of the rim flanges, enhancing lateral stiffness while maintaining low vertical stiffness, thus optimizing resin material usage and improving ride and handling performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the wall thickness of the tire frame member at the bead portions is increased to obtain sufficient handling performance, then lateral stiffness is improved, but vertical stiffness increases and the mass of the tire increases

Engineering Contradiction:
Improvelateral stiffnessVSAvoidmass of the tire
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The patent applies local quality by varying the wall thickness of the tire frame member in different regions. Specifically, the thick-walled portions are positioned at the bead portions to enhance lateral stiffness for handling performance, while the wall thickness decreases toward the side portions to reduce vertical stiffness and overall mass. This localized thickness variation allows each region to have the appropriate structural properties for its functional requirements.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent utilizes the radial dimension to create a gradient in wall thickness from the bead portions to the side portions. By positioning the thick-walled portions at specific radial locations (at the bead portions and decreasing toward the side portions), the design exploits the radial dimension to achieve differential stiffness characteristics without uniformly increasing mass throughout the entire tire frame member.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Strength

If the wall thickness of the tire frame member at the bead portions is increased to obtain sufficient handling performance, then lateral stiffness is improved, but the amount of resin material used increases

Engineering Contradiction:
Improvelateral stiffnessVSAvoidamount of resin material
Core Design Contradiction:
StrengthVSQuantity of substance

Solution Approach 1:

The patent applies local quality by varying the wall thickness of the tire frame member in different regions. Specifically, the thick-walled portions are positioned at the bead portions to enhance lateral stiffness for handling performance, while the wall thickness decreases toward the side portions to reduce vertical stiffness and overall mass. This localized thickness variation allows each region to have the appropriate structural properties for its functional requirements.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent applies partial action by increasing the wall thickness only where it is most needed for handling performance (at the bead portions) rather than uniformly throughout the entire frame member. The thick-walled portions are strategically located to provide the necessary lateral stiffness, while other regions use thinner walls to minimize resin material consumption.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP3805014B1tire
Publication Date: 2023.12.20 BRIDGESTONE CORP
  • EP3805014B1 patent drawingFigure 1
  • EP3805014B1 patent drawingFigure 2
  • EP3805014B1 patent drawingFigure 3

AI summary

A tire includes a tire frame member that has bead portions in which bead cores are embedded in a resin material and side portions that comprise the resin material and are continuous with tire radial direction outer sides of the bead portions, wherein assuming that T1 is a thickness of thick-walled portions of the tire frame member that are adjacent to the tire radial direction outer sides of the bead cores and that T2 is a thickness of the side portions, T1 > T2, a thickness of the tire frame member decreases from T1 to T2 between the thick-walled portions and the side portions, and a position at which the thickness of the tire frame member starts to decrease from T1 to T2 is on a tire radial direction outer side of tire radial direction outer ends of rim flanges of a rim on which the bead portions are mounted.