Tread Groove Cylindrical Bulges for Stress Reduction

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Solution Overview

Problem

Tread profiles with kinked grooves suffer from noise emission, stress cracks, premature wear, and impaired water and snow traction due to sharp transitions and corner stresses, which affect durability and grip performance.

Innovation Solution

A tread profile design featuring cylinder segment-shaped bulges in the transition areas of the grooves, which round the edges and maintain the groove cross-section open, ensuring reliable support and improved traction while reducing noise and stress concentrations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-generated harmful factors

If kinked transverse grooves are used to limit noise emission, then noise levels are reduced, but stress cracks and premature wear occur due to sharp transitions and corner stresses

Engineering Contradiction:
Improvenoise emissionVSAvoiddurability
Core Design Contradiction:
Object-generated harmful factorsVSReliability

Solution Approach 1:

The patent applies curvature by rounding the kink points of the transverse grooves with cylindrical segments instead of using sharp corners. This curvature eliminates stress concentration points that cause cracks and premature wear, while maintaining the noise-reducing kinked groove configuration. The rounded transitions prevent stress cracks in the transition areas and ensure reliable support when passing through the tire contact area.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Ease of manufacture

If sharp-edged transitions are used in groove flanks, then manufacturing is simpler, but water and snow traction is impaired due to groove closure

Engineering Contradiction:
Improvegroove formationVSAvoidimpaired grip effect
Core Design Contradiction:
Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The cylindrical segment rounding of the groove flanks at the kink points prevents the sharp edges from closing during tire flexing in the contact area. This curvature maintains the groove cross-section open, ensuring continuous water and snow evacuation capability while keeping the manufacturing process relatively simple.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Object-generated harmful factors

If kinked groove design is used to improve noise levels, then sound propagation is hindered, but stress cracks occur in the transition areas

Engineering Contradiction:
Improvenoise emissionVSAvoidresistance to stress cracks
Core Design Contradiction:
Object-generated harmful factorsVSStrength

Solution Approach 1:

The cylindrical segment rounding eliminates the sharp corners at the kink points that act as stress concentration points. The curved transition areas distribute stresses more evenly, preventing stress crack formation while maintaining the noise-reducing kinked groove geometry.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The rounded cylindrical segments at the kink points act as cushioning elements that preemptively reduce stress concentrations before cracks can form. This preventive design protects the transition areas from stress-induced damage while preserving the acoustic benefits of the kinked groove configuration.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentEP2455235B1Run strip profile of a vehicle tyre
Publication Date: 2014.04.30 CONTINENTAL REIFEN DEUTSCHLAND GMBH
  • EP2455235B1 patent drawingFigure 1~2
  • EP2455235B1 patent drawingFigure 3~5
  • EP2455235B1 patent drawingFigure 6~8

AI summary

The tread strip profile comprises transverse grooves (3), which are limited radially inward with a groove base and a groove wall on both sides of the groove base. The groove extends along its extension in the axial direction of the tire with a substantially rectilinear extension area (5), which extends up to a buckling point. A cylinder axis of the cylinder segment mold is extending in the radial direction through a profile element (2).