Tire Tread Sipe Segmentation for High-Speed Cornering

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Solution Overview

Problem

Tires with a middle rib configuration that includes an inner middle sipe extending inwardly and an outer middle sipe extending outwardly from main grooves fail to achieve desired performance, especially in high-speed cornering situations.

Innovation Solution

The tire design features a tread surface with alternating first and second sipes that communicate with circumferential grooves, where the first sipe has a larger width and angle than the second sipe, and both have bent portions to maintain shearing rigidity while reducing compression rigidity, enhancing turning performance at high speeds.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a middle rib includes an inner middle sipe extending inwardly from a shoulder main groove and an outer middle sipe extending outwardly from a crown main groove, then the tire structure is simplified, but the turning performance during high-speed cornering deteriorates

Engineering Contradiction:
Improvetread structure complexityVSAvoidturning performance during high-speed cornering
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The sipe structure is divided into multiple segments: first sipes and second sipes with different orientations, widths, and positions. This segmentation allows each sipe to perform specific functions - first sipes primarily reduce compression rigidity while second sipes maintain shearing rigidity, resolving the contradiction between structural simplicity and high-speed turning performance

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the middle rib are assigned different sipe characteristics. The first sipes are positioned and dimensioned to optimize compression deformation, while second sipes are positioned and dimensioned to maintain shearing resistance. This local differentiation enables the tread to exhibit optimized mechanical properties in different directional loads during high-speed cornering

Inventive Principle:
Principle #3Local quality

2Reliability

If sipes are made wider and more numerous to improve turning performance, then the shearing rigidity decreases, but this may cause excessive deformation and reduce durability

Engineering Contradiction:
Improveturning performanceVSAvoidshearing rigidity
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The sipe system is segmented into two functional groups with different geometric parameters. First sipes with specific widths and angles are optimized for compression deformation, while second sipes with different widths and angles are optimized for maintaining shearing rigidity. This segmentation allows the tire to achieve improved turning performance without excessive overall rigidity loss

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The first and second sipes are designed with asymmetric characteristics - different widths, different angles relative to the tire circumferential direction, and different positional arrangements. This asymmetry enables differential mechanical responses to compression and shearing loads, allowing the tire to deform appropriately under compression while maintaining resistance to shearing forces during high-speed cornering

Inventive Principle:
Principle #4Asymmetry

Data Source

PatentEP3643526B1tire
Publication Date: 2022.11.30 BRIDGESTONE CORP
  • EP3643526B1 patent drawingFigure 1
  • EP3643526B1 patent drawingFigure 2
  • EP3643526B1 patent drawingFigure 3

AI summary

Provided is a tire in which a first intermediate land portion 3b of most vehicle-installed outside includes a sipe extending in a tire width direction, the sipe comprises a first sipe So that communicates with a circumferential groove 2a adjacent to a vehicle-installed outside of the first intermediate land portion 3b, and terminates in the first intermediate land portion 3b, and a second sipe Si that communicates with a circumferential groove 2b adjacent to a vehicle-installed inside of the first intermediate land portion 3b, and terminates in the first intermediate land portion 3b, the first sipes So and the second sipes Si are alternately present in a tire circumferential direction, and a sipe width of the first sipe So is larger than a sipe width of the second sipe Si.