Pneumatic Tire Tread Arc Geometry for Rollover Resistance
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Solution Overview
Problem
Conventional pneumatic tires face challenges in maintaining driving stability and rollover resistance due to uneven tread wear and varying load conditions, which affect cornering forces and rollover characteristics.
Innovation Solution
A pneumatic tire design featuring a tread surface formed with multiple arcs of different curvature radii, where the center arc, shoulder-side arc, and shoulder arc are optimized in terms of curvature and positioning, along with specific angle and groove configurations, to enhance contact area and friction at varying loads, using a compound with a 300% tensile modulus of 5-10 MPa and anisotropic rubber for improved rollover resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the tread surface is designed with a conventional shape, then the tire structure is simple, but uneven tread wear occurs and driving stability deteriorates under varying load conditions
Solution Approach 1:
The tread surface is segmented into multiple arc portions (center arc, shoulder-side arc, and shoulder arc) with different curvature radii. Each arc portion is independently designed to optimize performance in specific regions, allowing the tire to maintain driving stability while managing the complexity through functional segmentation of the tread surface geometry.
2Reliability
If the tread contact area is increased to improve driving stability, then the maximum cornering force increases, but rollover resistance deteriorates
Solution Approach 1:
Different regions of the tread surface are given different geometric properties through the use of arcs with varying curvature radii. The center arc has a different curvature than the shoulder-side and shoulder arcs, creating local quality variations that optimize the balance between contact area for driving stability and cornering force control for rollover resistance.
3Force
If the tire is designed for high load performance, then the maximum cornering force is sufficient, but the contact area at low load is reduced, deteriorating driving stability
Solution Approach 1:
The tread surface geometry with multiple arcs of different curvature radii creates a dynamic contact characteristic that adapts to varying load conditions. At low loads, the geometric configuration maintains adequate contact area for stability, while at high loads, the same geometry provides sufficient cornering force, achieving dynamic performance across different operating conditions.
Data Source
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AI summary
To provide a pneumatic tire that can improve a rollover resistance while retaining a driving stability, a tread surface 11 is formed from a center arc 31, a shoulder-side arc 32, and a shoulder arc 33. Moreover, the tread surface 11 is formed in such a manner that a value obtained from a relation K1=L1/(TDW×0.5) satisfies 0.6≤K1≤0.8, where K1 is a relation between an outline area L1 that is a width from an equatorial plane 5 to the end of the center arc 31 and a tread development width TDW, and a ratio K2 satisfies 0.9≤K1≤2.0, where K2=TR1/OD, and K2 is a ratio of a curvature radius TR1 of the center arc 31 to a tire outside diameter OD. Furthermore, the tread surface 11 is formed in such a manner that a value obtained from a relation K3=(β×TDW)/(100×SW) satisfies 0.40≤3≤0.48, where k3 is a relation between an aspect ratio β, the tread development width TDW, and a total width SW. As a result, the rollover resistance can be improved while retaining the driving stability.