Tread Sipe Geometry for Wet Grip Retention During Tire Wear
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Solution Overview
Problem
Tires with tread land sipes experience a deterioration in wet gripping performance as the tread surface wears, due to increased compressive stiffness reducing contact area with the road surface.
Innovation Solution
Incorporating sipes with widened portions that have a larger cross-sectional area on the inside than the outside in the tire radial direction, which helps maintain wet gripping performance by preventing an increase in compressive stiffness as the tread wears.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If sipes are provided in the tread land portion to improve wet gripping performance, then wet gripping performance is improved in the initial state, but compressive stiffness of the tread land portion increases as wear progresses, causing contact area to decrease and wet gripping performance to deteriorate
Solution Approach 1:
The sipe is designed with non-uniform width along its radial direction, creating local quality variations. The widened portion at the inner side provides different mechanical properties compared to the outer side, allowing the sipe to maintain flexibility and contact area while reducing overall compressive stiffness increase during wear progression
Solution Approach 2:
The sipe geometry is changed by creating a widened portion with larger cross-sectional area at the inner side. This parameter change in the sipe structure allows it to better accommodate wear progression while maintaining wet gripping performance, as the varied cross-section modifies stress distribution and prevents excessive stiffness increase
Data Source
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AI summary
A tire according to the present disclosure is a tire including, in a tread surface, a tread land portion partitioned by a partitioning groove or by the partitioning groove and a tread edge. The tread land portion includes a sipe extending from a surface of the tread land portion inwardly in a tire radial direction. The sipe includes a widened portion with a larger sipe width than a position adjacent in a sipe longitudinal direction. The cross-sectional area of the widened portion in cross section perpendicular to the tire radial direction is larger on inside than on outside in the tire radial direction.