Pneumatic Tire Tread with Variable Rubber Layer Volumes
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Solution Overview
Problem
Existing pneumatic vehicle tires face a conflict between achieving good wet grip and low rolling resistance, as improvements in one often result in compromises in the other, with prior art tires suffering from increased rolling resistance due to wet grip optimization in shoulder areas.
Innovation Solution
The tire design features a radially outer rubber layer that extends beyond the tread width on the shoulder side, with a volume proportion of 20-30% in these sections and 30-50% in the central section, where a rolling resistance-optimized rubber layer predominates in shoulder areas and balanced wet grip-optimized rubber layers are used in the middle area, with specific thickness and resilience values for each layer to balance properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the tread consists primarily of wet grip-optimized rubber layer in shoulder areas, then wet grip is improved, but rolling resistance increases
Solution Approach 1:
The patent applies local quality by using different rubber layer compositions in different tread zones. The shoulder areas (15-25% width from edges) have outer rubber layer volume of 20-30% optimized for wet grip, while the central area (50-70% width) has outer rubber layer volume of 30-50% balancing wet grip and rolling resistance. This spatial variation in material properties resolves the contradiction by optimizing each zone for its specific functional requirements.
Solution Approach 2:
The patent segments the tread into distinct zones based on width proportions: shoulder-side sections (15-25% of tread width) and middle section (50-70% of tread width). Each segment has different rubber layer volume ratios, with the outer rubber layer occupying 20-30% in shoulders and 30-50% in the center. This segmentation allows independent optimization of wet grip in shoulders and rolling resistance in the center.
2Reliability
If the outer rubber layer thickness increases towards the tire zenith, then wet grip is improved, but the volume proportion in shoulder areas increases rolling resistance
Solution Approach 1:
The patent implements local quality by specifying that the outer rubber layer thickness increases constantly in the direction of the tire zenith, but controls the volume proportion to 20-30% in shoulder sections. This allows the zenith area to benefit from increased thickness for wet grip while limiting shoulder area volume to minimize rolling resistance.
Solution Approach 2:
The patent applies parameter changes by controlling the outer rubber layer volume to specific ranges (20-30% in shoulders, 30-50% in center) while allowing thickness to increase towards the zenith. This parameter optimization resolves the contradiction by adjusting the volume proportion parameter in different zones to balance wet grip and rolling resistance.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design achieves improved wet grip and reduced rolling resistance by optimizing rubber layer volumes and resilience, ensuring better performance in both aspects, especially with new tires.
Implementation Method 1
the outer rubber layer has a lower rebound resilience than the inner rubber layer
Implementation Method 2
the heat build-up of the inner rubber layer is lower than that of the outer rubber layer
Implementation Method 3
about two-thirds of the rolling resistance of a tire's tread is generated in the shoulder areas of the tire and only about one-third in the center of the tire
Data Source
Figure 1
AI summary
Radial pneumatic tire for vehicles with a radial carcass (3), a multi-layer belt structure (2) and a tread (1) which in the profiled area has a tread section (7) which is composed of a radially outer rubber layer (9) whose thickness increases continuously towards the tire zenith and a radially inner rubber layer (10), wherein the outer rubber layer (9) has a lower rebound elasticity than the inner rubber layer (10), which extends beyond the width (B) of the tread (1) on the shoulder side in the ground contact area.The radial outer rubber layer (9) also extends beyond the width (B) of the tread (1) in the ground contact area on the shoulder side, wherein the volume of the outer rubber layer (9) in shoulder-side sections (11), the width (bl) of which is 15% to 25% of the width (B) of the tread (1) in the ground contact area, occupies between 20% and 30% of the volume of the tread portion (7) in these sections (11), and wherein the volume of the radial outer rubber layer (9) in the central section (12) running between the shoulder-side sections (11) occupies 30% to 50% of the volume of the tread portion (7) in this section (12).