Two-Wheeled Vehicle Tire Side Surface Geometry for Stability and Absorbability

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Solution Overview

Problem

Existing pneumatic tires for two-wheeled vehicles face challenges in achieving both stability and absorbability, as high rigidity leads to reduced absorbability and low rigidity results in compromised stability.

Innovation Solution

The tire design features a tread with side surfaces extending inward in a radial direction, beads with a core and apex, and a carcass structure that includes a band with organic fibers, where the side surfaces and apex are positioned to form specific angles and ratios to enhance stability and absorbability, allowing the tire to flex while maintaining rigidity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the rigidity of the side part is increased to achieve good stability, then stability is improved, but absorbability deteriorates

Engineering Contradiction:
ImprovestabilityVSAvoidabsorbability
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The side part is divided into multiple regions with different rigidity characteristics. The upper side part (from the equator to the maximum width position) has different structural properties than the lower side part, allowing each region to contribute differently to stability and absorbability. This local differentiation enables the tire to exhibit appropriate rigidity in different zones simultaneously.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The side part structure is designed to dynamically adapt to different operational conditions. The specific geometric configuration (with the reference line at 45-75 degrees to the bead base line and the apex height ratio of 0.5 or more) allows the side part to flex appropriately under load while maintaining structural integrity, achieving both stability and absorbability through dynamic response rather than static rigidity.

Inventive Principle:
Principle #15Dynamics

2Reliability

If the rigidity of the side part is decreased to improve absorbability, then absorbability is improved, but stability deteriorates

Engineering Contradiction:
ImproveabsorbabilityVSAvoidstability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

Different regions of the side part are assigned different structural characteristics. The upper region provides flexibility for absorbability while the lower region maintains structural support for stability. This local quality differentiation resolves the contradiction by allowing each region to optimize for its primary function.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The side part structure dynamically responds to applied loads by flexing in controlled manner. The geometric parameters (reference line angle of 45-75 degrees, apex height ratio ≥0.5) enable the structure to transition between rigid and flexible states as needed, achieving both stability at rest and absorbability under load.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3078510B1Pneumatic tire for two-wheeled vehicle
Publication Date: 2017.11.22 SUMITOMO RUBBER INDUSTRIES LTD
  • EP3078510B1 patent drawingFigure 1
  • EP3078510B1 patent drawingFigure 2
  • EP3078510B1 patent drawingFigure 3

AI summary

A pneumatic tire for a two-wheeled vehicle includes a tread, side walls, and beads. When the tire is on normal rim and filled to normal internal pressure, each side surface (52) has reference position (PR) corresponding to radial direction outer edge of each side surface in contact with the rim, and reference line (L1) passing through the reference position (PR) and edge (PT) of the tread surface such that the reference line (L1) is in contact with the rim at the reference position and each side surface (52) extends along the reference line (L1) between the reference position (PR) and edge (PT) of the tread surface, absolute value of angle formed by the reference line (L1) and bead base line (BBL) is from 45 to 75 degrees, and ratio of radial direction height (HA) from the reference position to outer edge (44) of the apex (40), to radial direction height (HS) from the reference position to the edge (PT) of the tread surface, is 0.5 or more.