Pneumatic Tire Sipes with Variable Depth for Wet Traction and Wear
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Pneumatic tires face a trade-off between wet traction and wear resistance, where increased sipes for improved wet traction lead to decreased stiffness and wear resistance on dry roads, and vice versa, with existing solutions failing to maintain effective wet traction as tires wear.
Innovation Solution
A pneumatic tire design featuring multiple land portions with dent parts on both side walls, where sipes traverse in the tire width direction with greater depth at the ends than in the center, and a two-stepped cross-sectional shape to enhance stiffness and drainage, maintaining excellent wet traction and wear resistance from early to advanced stages of wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an increased number of sipes or deeper sipes are formed in tread land portions, then wet traction is improved, but the stiffness of the land portions decreases and wear resistance on dry roads decreases
Solution Approach 1:
The sipes are designed with non-uniform depth characteristics: deeper at the end portions (opening to grooves) and shallower at the center portion. This local variation allows the end portions to provide effective drainage for wet traction while the shallower center portion maintains land stiffness and wear resistance.
Solution Approach 2:
The sipe structure is segmented into different depth zones (deeper end portions and shallower center portion), allowing each segment to serve different functions: end portions for drainage and wet traction, center portion for maintaining stiffness and wear resistance.
2Strength
If the depth of sipes formed in the tread land portions is decreased, then wear resistance is improved, but wet traction sharply decreases when wear reaches an advanced stage
Solution Approach 1:
The sipes are pre-designed with greater depth at the end portions that open to grooves, ensuring that drainage capability is maintained even as the tire wears. The deeper end portions are positioned to remain effective throughout the tire's service life, providing preliminary assurance of wet traction performance.
Solution Approach 2:
Different portions of the sipe structure have different depth characteristics tailored to their specific functions: the end portions (critical for drainage) are deeper, while the center portion is shallower. This local differentiation ensures wet traction is maintained throughout the wear cycle.
3Strength
If a sipe is formed to have shallow end parts on the opening sides, then the stiffness of the block is ensured, but wet traction sharply decreases when wear reaches an advanced stage due to disappearance of sipes on opening sides
Solution Approach 1:
Instead of making the end portions shallow (as in conventional designs), the invention inverts the approach by making the end portions deeper and the center portion shallower. This inversion ensures that the portions critical for drainage (end portions opening to grooves) maintain greater depth and effectiveness throughout the tire's service life.
Solution Approach 2:
The sipe structure implements local quality differentiation with deeper end portions for drainage and shallower center portions for stiffness, reversing the conventional shallow-end design to optimize both wet traction and durability.
Data Source
Figure 1~3
Figure 4~5
Figure 6~7
AI summary
Provided is a pneumatic tire which achieves both of excellent wet traction and wear resistance from an early stage to an advanced stage of wear. Multiple dent parts (5) are formed, at certain intervals in a tire circumferential direction, in both side walls of each of at least two land portions (12) of multiple land portions being formed in a tread surface and extending in the tire circumferential direction. Each of the dent parts has a smaller depth than main grooves (2,3) that define the land portion where this dent part is formed. Multiple sipes (6) are formed to traverse the land portion in a tire width direction between the right and left dent parts opposed to each other. Each of the sipes has a greater depth in both end regions opening to the dent parts than in a center region thereof.