Tire Shoulder Wear Suppression via Zigzag Sipe Segmentation
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Solution Overview
Problem
Tires with high vehicle height, especially small vehicles and minivans, experience significant shoulder uneven wear due to the high center of gravity, leading to increased load on the shoulder land portion during turning, which conventional techniques fail to effectively address.
Innovation Solution
A tire design featuring width direction sipes with zigzag portions in a zigzag shape in the tire circumferential direction, longer in the center and inner shoulder regions than the intermediate region, and a straight portion from the tread surface to a predetermined depth, with a specific ratio of straight to zigzag portions and bent portions, to enhance block rigidity and reduce ground contact pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the vehicle height is increased to improve comfortability and cargo capacity, then the vehicle can accommodate more cargo and provide better comfort, but the center of gravity becomes higher causing increased load on the shoulder land portion and shoulder uneven wear
Solution Approach 1:
The shoulder land portion is segmented into multiple regions (center region, intermediate region, shoulder region) with different zigzag portion configurations. This segmentation allows each region to be optimized independently for its specific functional requirements, addressing the uneven wear problem caused by high vehicle height and cargo capacity demands.
Solution Approach 2:
Different regions of the shoulder land portion are given different local qualities through varying zigzag portion lengths and bent portion numbers. The center and shoulder regions have longer zigzag portions for enhanced stability, while the intermediate region has shorter zigzag portions, creating localized property variations that address the specific wear patterns caused by high center of gravity.
2Object-affected harmful factors
If conventional techniques such as lateral grooves are used to suppress shoulder uneven wear, then partitioning the shoulder land portion can reduce wear, but deformation of the shoulder land portion cannot be suppressed and heel and toe wear still occurs
Solution Approach 1:
Instead of using straight lateral grooves that partition the shoulder land portion, the invention uses zigzag-shaped portions that curve back and forth. This curvature allows the sipes to suppress wear while maintaining the structural integrity and stability of the shoulder land portion, preventing both uneven wear and deformation.
Solution Approach 2:
The width direction sipe combines different structural elements (straight portion and zigzag portion) with different functions into a composite structure. The straight portion provides depth control while the zigzag portion provides wear suppression, creating a composite solution that addresses multiple problems simultaneously without causing deformation.
3Strength
If the zigzag portion length is increased in all regions to improve block rigidity, then shoulder uneven wear can be suppressed, but the intermediate region may become overly rigid affecting tire flexibility and comfort
Solution Approach 1:
The invention applies different zigzag portion lengths to different regions based on their specific requirements. The center and shoulder regions have longer zigzag portions for enhanced block rigidity and wear suppression, while the intermediate region has shorter zigzag portions to maintain flexibility and comfort, avoiding excessive rigidity in any single area.
Data Source
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AI summary
To provide a tire capable of suppressing shoulder uneven wear effectively when the tire is mounted to a vehicle having high vehicle height. In a tire according to the present invention, a width direction sipe (100) is formed. The width direction sipe (100) is provided with a zigzag portion (112) formed in a zigzag shape in a tire circumferential direction toward an inner side of a tire radial direction, a center region Wctr, an inner shoulder region Win, and an intermediate region Wmid. The zigzag portion (112) in the center region Wctr and the zigzag portion (112) in the inner shoulder region Win are longer than the zigzag portion (112) in the intermediate region Wmid in the tire radial direction.