Pneumatic Tyre Groove Chamfers Stone Ejection

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Solution Overview

Problem

Pneumatic vehicle tires with stone ejector projections face challenges in water drainage due to reduced groove volume, which affects their performance on wet surfaces and increases the likelihood of stones getting stuck.

Innovation Solution

Chamfering the groove edges around free-standing projections to increase the groove volume, enhance water absorption, and improve traction, while maintaining the stone-ejecting effectiveness by ensuring the chamfers project beyond the projections in opposite directions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If free-standing projections are formed at the groove bottom to eject stones, then stone ejection effectiveness is improved, but groove volume is reduced which worsens water drainage properties

Engineering Contradiction:
Improvestone ejection effectivenessVSAvoidgroove volume
Core Design Contradiction:
ReliabilityVSVolume of stationary object

Solution Approach 1:

The groove is segmented into multiple functional zones: the groove base with free-standing projections for stone ejection, and chamfered groove edges for water drainage. This segmentation allows each zone to perform its specific function optimally without compromising the other.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention adds chamfers to the groove edges, introducing a new dimensional element (the chamfered surface) that provides additional water drainage capacity without interfering with the vertical projections at the groove base. This dimensional addition resolves the volume conflict.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If free-standing projections are formed at the groove bottom to eject stones, then stone ejection effectiveness is improved, but likelihood of stones getting stuck increases due to reduced groove cross-section

Engineering Contradiction:
Improvestone ejection effectivenessVSAvoidlikelihood of stones getting stuck
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The groove structure is divided into distinct functional areas: the groove base with projections for active stone ejection, and the chamfered edges that provide smooth transition zones preventing stone entrapment. This segmentation eliminates the harmful effect of stones getting stuck while preserving ejection effectiveness.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The chamfered groove edges act as intermediary elements between the stone and the groove base projections. They provide a gradual transition that prevents stones from getting abruptly trapped, mediating the interaction between stones and the groove structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Volume of stationary object

If groove volume is increased to improve water drainage, then water drainage properties are improved, but stone ejection effectiveness is reduced due to smaller projection size

Engineering Contradiction:
Improvegroove volumeVSAvoidstone ejection effectiveness
Core Design Contradiction:
Volume of stationary objectVSReliability

Solution Approach 1:

The groove is segmented into volume-providing chamfered edges for water drainage and compact projection structures for stone ejection. This segmentation allows the groove to have sufficient overall volume for drainage while maintaining small, effective projections for stone ejection.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different parts of the groove have different qualities: the groove edges are chamfered to provide water drainage volume, while the groove base maintains compact projections for effective stone ejection. Each local area is optimized for its specific function.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3620311B1Pneumatic tyre
Publication Date: 2021.06.16 CONTINENTAL REIFEN DEUTSCHLAND GMBH
  • EP3620311B1 patent drawingFigure 1
  • EP3620311B1 patent drawingFigure 2
  • EP3620311B1 patent drawingFigure 3~5

AI summary

The invention relates to a vehicle pneumatic tire with a tread featuring profile positives, such as profile bands or profile block rows, which are arranged around the tread circumference according to a pitch sequence of at least two pitches (L, M, K) with different circumferential lengths (lL, lM, lK), and with at least one circumferential groove (2) designed to a tread depth (T1) with a groove base (2a), groove flanks (2b) and groove edges (2c), wherein a plurality of spaced-apart, freestanding projections (6) are formed on the groove base (2a), which have a height (hi) of 10% to 30% of the tread depth (T1), a width (b1) of 25% to 40% of the width (B1) of the circumferential groove (2) and an extension length (l1) of 15% to 40% of the circumferential length (lL, lM, lK) of the respective pitch (L, M, K).Laterally, on each freestanding projection (6), both groove edges (2c) of the circumferential groove (2) are chamfered in such a way that the groove flanks (2b) have chamfers (2'b) which each project beyond the freestanding projection (6) in the circumferential direction at least on one side.