Tyre Tread Land Segmentation for Steering Stability and Noise

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Solution Overview

Problem

Tyres with asymmetric tread patterns for improved steering stability generate noise due to the wide land region on the outer side, necessitating a solution that enhances both steering stability and noise performance.

Innovation Solution

A tyre design with a tread portion featuring an outer tread edge on the outer side, an inner tread edge on the inner side, and specific groove and sipe configurations, including first, second, and third sipes, and inner lateral grooves, to manage ground contact pressure and noise transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If a wide land region is positioned on the outer side of the vehicle to improve steering stability, then steering stability is improved, but impact sound is transmitted toward the outer side of the vehicle resulting in poor noise performance

Engineering Contradiction:
Improvesteering stabilityVSAvoidimpact sound
Core Design Contradiction:
Stability of the object's compositionVSObject-generated harmful factors

Solution Approach 1:

The outer land region is divided into multiple segments by introducing first sipes extending in the tire circumferential direction and second sipes extending in the tire radial direction. This segmentation breaks up the continuous wide land region into smaller contact patches, which reduces the transmission of impact sound to the vehicle interior while preserving the overall wide contact area needed for steering stability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the outer land region are given different properties through the strategic placement of sipes. The first sipes create longitudinal grooves that help dissipate impact energy, while the second sipes create radial grooves that further fragment the contact area. This local modification of the land region structure reduces noise transmission while maintaining the necessary structural integrity for steering stability.

Inventive Principle:
Principle #3Local quality

2Object-generated harmful factors

If sipes are added to the center land region to reduce noise, then noise performance is improved, but steering stability may be compromised

Engineering Contradiction:
Improveimpact soundVSAvoidsteering stability
Core Design Contradiction:
Object-generated harmful factorsVSStability of the object's composition

Solution Approach 1:

The center land region is segmented by first sipes that extend completely across it in the circumferential direction. This segmentation reduces the continuous contact area in the center region, thereby reducing impact sound transmission. The segmentation is designed to be sufficient for noise reduction while maintaining adequate contact area for steering stability.

Inventive Principle:
Principle #1Segmentation

3Stability of the object's composition

If the outer land region width is increased to improve steering stability, then steering stability is improved, but the noise transmission to the vehicle interior increases

Engineering Contradiction:
Improvesteering stabilityVSAvoidnoise transmission
Core Design Contradiction:
Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The outer land region is segmented by both first sipes (circumferential) and second sipes (radial), creating a grid-like pattern of smaller contact elements. This double segmentation approach effectively reduces the transmission of impact sound through the wide outer land region to the vehicle interior, while the overall wide dimension is preserved for steering stability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The outer land region is given locally differentiated properties through the strategic placement of sipes at specific positions and orientations. This creates zones of varying compliance and noise transmission characteristics within the wide outer land region, reducing overall noise transmission while maintaining the structural framework needed for steering stability.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3564047B1tyre
Publication Date: 2020.10.07 SUMITOMO RUBBER INDUSTRIES LTD
  • EP3564047B1 patent drawingFigure 1
  • EP3564047B1 patent drawingFigure 2
  • EP3564047B1 patent drawingFigure 3

AI summary

A tyre whose position when mounted on a vehicle is specified has a tread portion in which an outer tread edge (To) and an inner tread edge (Ti) are defined. The tread portion has a first main groove (3), a second main groove (4) arranged on a side of the inner tread edge (Ti) of the first main groove (3), an outer land region (5) defined between the outer tread edge (To) and the first main groove (3), a center land region (6) defined between the first main groove (3) and the second main groove (4), and an inner land region (7) defined between the second main groove (4) and the inner tread edge (Ti). A width (W1) in a tyre axial direction of the outer land region is larger than a width in the tyre axial direction of each of the center land region (6) and the inner land region (7). The center land region (6) is provided with first sipes (11) each completely crossing the center land region (6).