Vehicle Tire Tread Cap Base Wear Detection

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Solution Overview

Problem

Existing vehicle tires with cap-base tread structures face challenges in detecting uneven wear, particularly in the shoulder area, leading to potential safety issues due to the similarity in appearance between the tread cap and base when both contain soot-containing rubber mixtures, making it difficult to notice wear until it's severe.

Innovation Solution

A pneumatic vehicle tire design featuring a tread cap with a filler system comprising more than 80% silica and carbon black, and a tread base made from a soot-free, non-black rubber mixture with high natural rubber content, ensuring the base is visibly distinct when the cap wears down, thereby improving safety and driving behavior.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If both cap and base contain soot-containing rubber mixtures, then abrasion resistance is improved, but wear detection capability deteriorates

Engineering Contradiction:
Improveabrasion resistanceVSAvoidwear detection capability
Core Design Contradiction:
StrengthVSDifficulty of detecting and measuring

Solution Approach 1:

The patent applies color differentiation by making the cap black (containing soot) and the base non-black (free of soot). This visual contrast enables easy detection of wear patterns and base exposure without compromising the abrasion resistance of the cap, which maintains its soot-containing compound for durability.

Inventive Principle:
Principle #32Color changes

2Loss of energy

If cap is made thin for better contact, then rolling resistance is reduced, but wear detection is delayed

Engineering Contradiction:
Improverolling resistanceVSAvoidwear detection timing
Core Design Contradiction:
Loss of energyVSDifficulty of detecting and measuring

Solution Approach 1:

The non-black base provides immediate visual indication when the thin cap becomes worn through, allowing drivers to detect wear at the optimal moment. This resolves the contradiction by enabling wear detection despite the reduced cap thickness needed for low rolling resistance.

Inventive Principle:
Principle #32Color changes

3Loss of energy

If silica content in cap is increased for rolling resistance, then fuel efficiency is improved, but abrasion resistance may deteriorate

Engineering Contradiction:
Improvefuel efficiencyVSAvoidabrasion resistance
Core Design Contradiction:
Loss of energyVSStrength

Solution Approach 1:

The patent applies different filler compositions to different parts: the cap contains soot and silica optimized for abrasion resistance, while the base uses high silica content (≥50 phr) optimized for low rolling resistance and fuel efficiency. This local differentiation allows each part to have optimal properties for its specific function.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The tread structure uses composite material strategies by combining different filler systems (soot-silica in cap, silica-dominant in base) to achieve both high abrasion resistance in the contact area and low rolling resistance in the base layer, resolving the fuel efficiency vs. abrasion resistance contradiction.

Inventive Principle:
Principle #40Composite materials

Data Source

PatentEP3524639B1Vehicle tyres
Publication Date: 2020.10.07 CONTINENTAL REIFEN DEUTSCHLAND GMBH

AI summary

The invention relates to a vehicle tire. The vehicle tire according to the invention comprises a tread, wherein the tread comprises a tread cap and a tread base, wherein the tread cap completely covers the tread base radially outwards, wherein the tread cap comprises at least a first rubber compound A, which contains a filler system comprising at least carbon black and more than 80 wt.%, preferably more than 90 wt.%, at least one silica, based on the total amount of fillers; and wherein the tread base comprises at least a second rubber compound B, which is free of carbon black and which is not black and which contains at least 50 phr natural rubber (NR).