Tread Sipe and Narrow Groove Layout for Ice Braking Tires

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Solution Overview

Problem

Tires with sipes in the same block disposed separated in the tire width direction face challenges in improving braking performance on ice and running performance on snow.

Innovation Solution

A tire design featuring circumferential main grooves, lug grooves, and land portions with sipes and narrow grooves that intersect these grooves, where the sipes and narrow grooves have specific angles and depths, and are arranged to optimize contact pressure distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If sipes are disposed separated in the tire width direction to prevent clogging of snow or ice, then braking performance on ice is improved, but ground contact pressure locally increases and load durability performance degrades

Engineering Contradiction:
Improvebraking performance on iceVSAvoidload durability performance
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent applies local quality by providing circumferential grooves specifically in portions where sipes are separated in the tire width direction, rather than uniformly across the entire tread. This localized groove configuration addresses the specific problem of ground contact pressure concentration at sipe separation points without compromising the overall load durability of the tire structure.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent segments the tread surface by dividing it into multiple land portions with separated sipes in the width direction, and further segments these land portions by introducing circumferential grooves. This segmentation creates smaller, more manageable contact areas that distribute ground contact pressure more evenly, preventing local pressure buildup while maintaining the sipe separation configuration needed for ice braking performance.

Inventive Principle:
Principle #1Segmentation

2Reliability

If sipes are disposed separated in the tire width direction to improve braking performance on ice, then running performance on snow is improved, but ground contact pressure distribution becomes uneven

Engineering Contradiction:
Improverunning performance on snowVSAvoidground contact pressure distribution
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent introduces circumferential grooves specifically in the regions where sipes are separated in the tire width direction. This local modification addresses the pressure distribution issue at critical locations without changing the overall sipe separation configuration that provides good snow running performance.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent adds circumferential grooves that extend in the tire circumferential direction, creating a new dimensional feature perpendicular to the sipe separation direction. This additional dimensional element helps distribute ground contact pressure more uniformly across the tread surface while preserving the beneficial sipe separation arrangement for snow performance.

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

Data Source

PatentEP4212361B1tire
Publication Date: 2025.11.19 THE YOKOHAMA RUBBER CO LTD
  • EP4212361B1 patent drawingFigure 1
  • EP4212361B1 patent drawingFigure 2
  • EP4212361B1 patent drawingFigure 3

AI summary

Provided is a tire that can provide improved braking performance on ice and running performance on snow. Provided in a tread portion are a plurality of circumferential main grooves, a plurality of lug grooves extending in a direction intersecting the circumferential main grooves, and a plurality of land portions defined by the circumferential main grooves and arranged in the direction intersecting the circumferential main grooves. A specific land portion that is at least one of the land portions includes, in a ground contact surface, a plurality of sipes extending in the direction intersecting the circumferential main grooves and a plurality of narrow grooves extending in the direction intersecting the circumferential main grooves and having a groove depth of 1.50 mm or less. In a central region in the tire width direction, the sipes and the narrow grooves have different directions extending in the tire circumferential direction when extending from one side toward another side in a width direction. In both edge regions on an outer side from the central region in the tire width direction, the sipes and the narrow grooves have the same direction extending in the tire circumferential direction when extending from the one side toward the other side in the width direction. The specific land portion includes a land portion including at least one land portion on an outer side in the tire width direction.