Tire Buttress Groove-Ridge Layout for Snow Grip and Steering Stability

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Solution Overview

Problem

Existing tires face challenges in achieving improved on-snow performance and steering stability, particularly due to stiffness differences between the buttress and sidewall portions, which affect traction and handling on both snowy and dry road surfaces.

Innovation Solution

The tire features a buttress surface with alternately arranged line grooves recessed inward and ridges protruding outward, which reduces stiffness differences and enhances traction on snow while maintaining steering stability on dry roads by optimizing the arrangement and dimensions of these features.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If rubber volume is increased by protrusions on the buttress portion, then on-snow performance is improved, but steering stability on dry road surface deteriorates due to large stiffness difference

Engineering Contradiction:
Improveon-snow performanceVSAvoidsteering stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The invention applies local quality by creating alternating protrusions and recesses on the buttress portion surface. This pattern provides localized rubber volume increases for snow traction while maintaining overall stiffness balance. The recesses strategically placed between protrusions reduce the total rubber volume compared to uniform protrusion coverage, thereby reducing stiffness difference with sidewall portion and improving steering stability on dry roads.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The buttress portion surface is segmented into alternating protrusions and recesses rather than using a uniform structure. This segmentation allows different zones to serve different functions: protrusions provide snow grip while recesses reduce overall stiffness. The segmented pattern optimizes the balance between on-snow performance and steering stability by distributing rubber volume non-uniformly across the buttress portion.

Inventive Principle:
Principle #1Segmentation

2Force

If protrusions are formed on the buttress surface to enhance stiffness, then on-snow traction is improved, but local strain increases leading to reduced steering stability

Engineering Contradiction:
Improvetraction force on snowVSAvoidlocal strain
Core Design Contradiction:
ForceVSStress or pressure

Solution Approach 1:

Local quality is applied by creating alternating protrusions and recesses on the buttress portion. The protrusions provide localized stiffness enhancement for snow traction, while the recesses between them reduce cumulative rubber volume and associated local strain. This alternating pattern optimizes the distribution of stress and strain across the buttress portion during steering operations.

Inventive Principle:
Principle #3Local quality

3Reliability

If the stiffness difference between buttress portion and sidewall portion is large, then on-snow performance is enhanced, but steering stability deteriorates

Engineering Contradiction:
Improveon-snow performanceVSAvoidsteering stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

Parameter changes are applied by modifying the surface geometry of the buttress portion with alternating protrusions and recesses. This changes the effective rubber volume and stiffness characteristics. The recesses reduce the total rubber volume compared to a fully protruded surface, thereby reducing the stiffness difference between buttress portion and sidewall portion while maintaining sufficient protrusions for snow traction.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4205997B1tire
Publication Date: 2024.07.24 SUMITOMO RUBBER INDUSTRIES LTD
  • EP4205997B1 patent drawingFigure 1
  • EP4205997B1 patent drawingFigure 2
  • EP4205997B1 patent drawingFigure 3

AI summary

Provided is a tire capable of improving steering stability on a dry road surface and on-snow performance. A tire 1 includes a buttress surface 13 extending inward in a tire radial direction from a tread ground-contact end Te. The tire 1 has a plurality of line grooves 15 recessed inward from the buttress surface 13 and extending on the buttress surface 13 and a plurality of ridges 16 protruding outward from the buttress surface 13 and extending on the buttress surface 13. The line grooves 15 and the ridges 16 are alternately arranged.