Tread Block Sipe End Wall Inclination for Grip Stability
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Solution Overview
Problem
Pneumatic tire sipes deform excessively under transversal loading during curved driving, leading to reduced grip and handling issues, as they are not optimized for centrifugal forces that cause asymmetrical contact patch distribution between inner and outer tires.
Innovation Solution
Inclining the first end wall of sipes closer to the outer side of the tire and maintaining a radially oriented second end wall to enhance rigidity and grip, while allowing suitable softness in the circumferential direction, thereby improving tire handling and grip, especially at high speeds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If sipes are provided in the tread to increase friction and soften the tread, then grip during breaking and accelerating is improved, but the tread becomes too soft for stable handling during curved driving
Solution Approach 1:
The patent applies different geometric configurations to different parts of the sipe structure. The first end wall is inclined to provide support and rigidity where needed, while the second end wall is substantially radial to maintain softness and flexibility in other areas. This local differentiation allows the sipe to simultaneously provide grip enhancement and structural stability.
Solution Approach 2:
The sipe structure is made asymmetric by having the first end wall inclined at a specific angle while the second end wall remains substantially radial. This asymmetric configuration creates different mechanical properties at each end of the sipe, allowing it to perform differently under various loading conditions - providing rigidity support during curved driving while maintaining softness for grip during breaking and accelerating.
2Strength
If sipes are configured for optimal grip during breaking and accelerating, then friction in forward and backward directions is improved, but the sipe configuration is not optimized for curved loading conditions
Solution Approach 1:
The sipe structure is designed to perform multiple functions by incorporating both an inclined first end wall for rigidity support during curved driving and a substantially radial second end wall for maintaining softness during breaking and accelerating. This multi-functional design allows the same sipe configuration to adapt to different loading conditions, providing both grip optimization and curved driving stability.
Data Source
Figure 1a~1b
Figure 2a~2b
Figure 2c~2d
AI summary
The invention relates to a tread block arrangement (160) of a tread band (150) or a tire (160). The tread block arrangement forms a tread (170) that is meant for a rolling contact against a ground surface (900), wherein the tread (170) is provided with at least one longitudinal groove (180, 182). The tread block arrangement (160) limits a first number (NT) of sipes, of which a second number (NTT) are transversal sipes (200, 210, Si, Sj), of which a third number (N) of sipes (Si, Sj) form a group (G1). For each sipe (Si) of the group (G1), the tread block arrangement (160) forms a bottom (221), a first sidewall (222), a second sidewall (224), and a first end wall (228, 228Si). The end first end wall (228Si) of each sipe (Si) of the group (G1) is configured such that a distance (d1,Si) between the first end wall (228Si) of the sipe (Si) in question and an outer side (172, 174) of the pneumatic tire (100) or the tread band (150) is less than a distance (d2,Si) between the other end (227Si) of the sipe (Si) in question and the outer side (172, 174). Moreover, at least a part of the first end wall (228Si) of the sipe (Si) in question has a first surface normal (N1si) of the sipe (Si) in question, and the first surface normal (N1si) of the sipe in question (Si) forms a first angle (βSi) of the sipe in question (Si) of at least 20 degrees with the tread (170). Furthermore, the ratio (NTT/NT) of the second number (NTT) to the first number (N) is at least 75 % and the ratio (N/NTT) of the third number (N) to the second number (NTT) is at least 20 %.