Tread Groove Pitch Layout for Tire Noise and Steering Stability

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Solution Overview

Problem

Existing tire designs that increase the number of axial grooves to improve noise performance often compromise steering stability due to reduced block rigidity.

Innovation Solution

A tire design featuring alternating arrangements of first and second axial grooves with specific pitch intervals and orientations that maintain steering stability while enhancing noise performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-generated harmful factors

If the number of axial grooves is increased to improve noise performance, then pitch noise is reduced, but the rigidity of blocks in the tread portion is reduced which impairs steering stability

Engineering Contradiction:
Improvepitch noiseVSAvoidblock rigidity
Core Design Contradiction:
Object-generated harmful factorsVSStrength

Solution Approach 1:

The patent applies local quality by differentiating the groove configurations between first and second land regions. The first land region has axial grooves with a first pitch arrangement optimized for one purpose, while the second land region has axial grooves with a second pitch arrangement optimized for another purpose. This allows different parts of the tread to have locally optimized properties - some areas prioritize noise reduction while others maintain steering stability.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent segments the tread portion into multiple land regions (first land region and second land region) separated by circumferential grooves. Each land region is further segmented into multiple blocks by axial grooves. This segmentation allows independent optimization of groove patterns in different regions, enabling the tire to achieve both noise reduction and steering stability through differentiated local configurations.

Inventive Principle:
Principle #1Segmentation

2Object-generated harmful factors

If the number of types of pitch intervals is increased to improve noise performance, then pitch noise variation is increased, but the complexity of the groove arrangement increases

Engineering Contradiction:
Improvepitch noise variationVSAvoidgroove arrangement complexity
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The patent implements local quality by assigning different pitch interval characteristics to different land regions. The first land region uses a first arrangement with a specific number of pitch types, while the second land region uses a second arrangement with a different number of pitch types. This localized differentiation allows the tire to achieve comprehensive noise reduction across various frequencies without requiring complex arrangements throughout the entire tread.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent segments the groove arrangement complexity across different regions. Rather than implementing a uniformly complex pattern throughout, the tread is divided into land regions where each can have appropriately complex or simple patterns based on its specific function. This segmentation manages overall complexity while achieving the desired noise performance.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4520548B1tire
Publication Date: 2026.03.25 SUMITOMO RUBBER INDUSTRIES LTD
  • EP4520548B1 patent drawingFigure 1
  • EP4520548B1 patent drawingFigure 2
  • EP4520548B1 patent drawingFigure 3

AI summary

A tire includes a tread portion having a first land region provided with first axial grooves and a second land region provided with second axial grooves. The first axial grooves are arranged at intervals in a first arrangement over the entire tire circumference. In the first arrangement, in a pair of adjacent first axial grooves, a first end of one first axial groove is located at the same position in the tire circumferential direction as the second end of the other first axial groove. The second axial grooves are arranged at intervals in a second arrangement. The number of types of a second pitch of the second axial grooves in the second arrangement is greater than the number of types of a first pitch of the first axial grooves in the first arrangement.