Tyre Sidewall Sectoring for Aerodynamic Drag Reduction

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Solution Overview

Problem

Conventional tires experience significant aerodynamic drag and increased energy consumption due to markings on the sidewalls, particularly those on the front axle, which contribute to energy losses during vehicle movement.

Innovation Solution

The tire design features sidewalls with specific sectors: the first sectors are devoid of relief markings, while the second sectors have markings in relief, with the first sectors forming angles of at least 20° and summing to 120°, and the second sectors having markings with a height of at least 0.2 mm, reducing aerodynamic drag without compromising legibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If markings in relief are provided on the sidewalls of the tire, then the legibility and identification information are improved, but the aerodynamic drag and energy consumption increase

Engineering Contradiction:
Improvelegibility of markingsVSAvoidaerodynamic drag
Core Design Contradiction:
Loss of informationVSLoss of energy

Solution Approach 1:

The sidewall is divided into multiple sectors with alternating patterns: some sectors have relief markings for legibility while others have smooth surfaces for aerodynamic performance. This segmentation allows the tire to simultaneously achieve both information visibility and reduced drag by distributing different surface characteristics across different angular positions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the sidewall are given different surface qualities - relief markings in specific sectors for identification purposes and smooth surfaces in other sectors for aerodynamic efficiency. This local differentiation allows each sector to fulfill its specific function without compromising the overall performance.

Inventive Principle:
Principle #3Local quality

2Loss of energy

If smooth sidewalls are used on the tire, then the aerodynamic drag is reduced, but the markings and identification information are lost

Engineering Contradiction:
Improveaerodynamic dragVSAvoidmarkings visibility
Core Design Contradiction:
Loss of energyVSLoss of information

Solution Approach 1:

The sidewall circumference is segmented into alternating smooth sectors and marked sectors. The smooth sectors minimize aerodynamic resistance while the marked sectors provide necessary identification information, allowing the tire to achieve low drag without complete loss of markings.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The sidewall features a periodic alternating pattern of smooth and marked sectors around the circumference. This periodic structure ensures that as the tire rotates, both smooth surfaces and marked surfaces are periodically exposed, maintaining aerodynamic efficiency while providing continuous visual information.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP2917048B1Tyre sidewall markings reducing aerodynamic drag
Publication Date: 2016.11.30 MICHELIN & CO (CIE GEN DES ESTAB MICHELIN)
  • EP2917048B1 patent drawingFigure 1
  • EP2917048B1 patent drawingFigure 2

AI summary

A tyre (1) for a passenger vehicle comprising a crown portion (2) provided with a tread, sidewalls (3, 3') and beads (4, 4') intended to be in contact with the rim (J) on which the tyre is mounted, at least one of the sidewalls comprising a plurality of first sectors (311) and seconds sectors (312) formed on the outer wall of a first sidewall portion (31) located between the points (F) axially furthest to the outside and the crown portion (2), the first sectors (311) being completely without raised markings of a height greater than 0.2 mm, whereas the second sectors (312) are provided with raised markings (3120) having a height at least equal to 0.2 mm, and the first sectors (311) each forming an angle ≥ 20°, the sum of the angles of said first sectors being ≥ 120 °.