Tire Tread Sipe Design for Wet Grip and Steering Stability
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Solution Overview
Problem
Existing tire tread designs face a trade-off between improving wet performance and maintaining steering stability, as increasing sipes for better wet grip can reduce the rigidity of the tread and deteriorate steering stability.
Innovation Solution
A tire tread pattern featuring main grooves and sipes strategically designed to maintain rigidity while enhancing wet performance, with inclined sipes and corner slopes that direct water flow effectively, ensuring improved traction without compromising steering stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the number of sipes is increased to improve wet performance, then wet grip performance is improved, but steering stability is deteriorated due to reduced rigidity of ground contacting land regions
Solution Approach 1:
The patent applies local quality by making the sipes asymmetric in design - the first sipes have different configurations than the second sipes. Specifically, the first sipes extend from the tread edge toward the center with certain depth and spacing, while the second sipes have different depth, spacing, or extension patterns. This local differentiation allows specific regions to provide wet grip enhancement while other regions maintain structural rigidity for steering stability.
Solution Approach 2:
The tread portion is segmented into different functional zones with distinct sipe configurations. The ground contacting land regions are divided into areas with first sipes and areas with second sipes, creating specialized zones that perform different functions - one zone optimized for water evacuation and grip, another zone optimized for maintaining rigidity and steering control.
2Reliability
If sipes are added to the tread portion to generate frictional force and edge effect on wet road surfaces, then wet performance is improved, but the rigidity of ground contacting land regions is reduced
Solution Approach 1:
Different regions of the tread portion are assigned different sipe characteristics to locally optimize for either wet performance or rigidity. The first sipes are configured to provide edge effect and friction on wet surfaces, while the second sipes are configured to maintain land region rigidity, creating a localized functional differentiation that resolves the strength-performance trade-off.
Solution Approach 2:
Instead of uniformly distributing sipes across all ground contacting regions (which would reduce rigidity everywhere), the patent inverts the approach by strategically placing different types of sipes in different locations. Some regions have aggressive siping for wet grip, while other regions have minimal or different siping to maintain rigidity, effectively using the absence or modification of sipes as the solution.
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
The tire achieves enhanced wet performance and balanced steering stability through a tread pattern that maintains rigidity and effectively directs water flow, as demonstrated by experimental results.
Implementation Method 1
the edges of the sipes can generate frictional force and exert an edge effect during running on wet road surfaces
Data Source
AI summary
A tire 1 comprises a tread portion 2 provided with an outboard shoulder land region 8 with outboard shoulder sipes 26. The outboard shoulder sipe 26 comprises a deep bottom part 27 and a shallow bottom part 28. The shallow bottom part 28 comprises an axially outer part 30 extending axially inwardly from the axially inner end 27i of the deep bottom part 27, an axially inner part 31 extending axially outwardly from the outboard shoulder main groove 4, and a middle part 32 connecting therebetween. The axially outer part 30, axially inner part 31 and middle part 32 have different angles with respect to the tire axial direction.