Crown Sipe Layout for Snow Traction and Dry Steering Stability
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Solution Overview
Problem
There is a demand for tyres that can maintain steering stability on dry roads while enhancing on-snow performance, a challenge that existing tyre designs have not fully addressed.
Innovation Solution
A tyre design featuring a tread portion with a crown land portion that includes multiple types of crown sipes (first, second, third, and fourth) with specific orientations, opening widths, and lengths, which open at the ground contact surface via chamfer portions to improve traction and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the crown land portion is provided with multiple types of crown sipes (first, second, third, and fourth) with specific orientations and varying opening widths, then on-snow performance is improved, but steering stability on dry roads may deteriorate
Solution Approach 1:
The patent applies local quality by creating different sipe configurations in specific regions of the crown land portion. First and second crown sipes with constant opening widths are positioned to maintain steering stability, while third crown sipes with continuously decreasing opening widths are positioned to enhance on-snow performance. This spatial differentiation of sipe characteristics allows each region to fulfill its specific functional requirement.
Solution Approach 2:
The crown land portion is segmented into multiple sipe systems (first, second, third, and fourth crown sipes) with distinct characteristics. Each sipe type has specific orientation angles, opening width variations, and positional arrangements that work together to simultaneously achieve dry road stability and on-snow traction without compromising either performance aspect.
2Reliability
If crown sipes have larger opening widths to improve traction on snow, then on-snow performance is enhanced, but ground contact area decreases affecting steering stability
Solution Approach 1:
The patent utilizes parameter changes by varying the opening width of different sipe types. Third crown sipes feature continuously decreasing opening widths from the first longitudinal edge toward the closed end, creating an optimized gradient that maximizes snow penetration capability while preserving sufficient ground contact area. This controlled parameter variation allows the sipes to adapt their effective opening width based on local requirements.
Data Source
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AI summary
A tread portion includes a crown land portion including first and second longitudinal edges extending in the tyre circumferential direction. The crown land portion is provided with first, second and third crown sipes. The first, second and third crown sipes open at the ground contact surface via respective chamfer portions. The first and third crown sipes extend from the first longitudinal edge and have closed ends in the ground contact surface. The second crown sipes extend from the second longitudinal edge and have closed ends in the ground contact surface. Each first crown sipe has a constant opening width in a longitudinal direction of the sipe. Each second crown sipe has a constant opening width in a longitudinal direction of the sipe. Each third crown sipe has an opening width which decreases continuously from the first longitudinal edge toward the closed end thereof.