Pneumatic Tire Tread Groove Width Ratio for Wet Wear Balance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Pneumatic tires face a challenge in balancing wet performance and wear resistance, as increasing groove volume to improve wet performance can lead to reduced actual ground contact area and rubber volume, resulting in deteriorated wear resistance and potential uneven wear due to insufficient block rigidity and inadequate water drainage.
Innovation Solution
The tire features a specific groove width ratio and pattern with center, middle, and shoulder lateral grooves, where the groove width of shoulder lateral grooves is 1.6 to 2.0 times that of center lateral grooves, and center lateral grooves are inclined to facilitate water discharge, combined with a directional tread pattern and zigzag main grooves to enhance drainage and rigidity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the groove volume is increased by decreasing the land ratio of the tread portion, then the drainage in the tread portion is increased and wet performance is improved, but the actual ground contact area and rubber volume are reduced, leading to deteriorated wear resistance
Solution Approach 1:
The patent applies local quality by differentiating the groove width across different regions of the tread. The shoulder lateral grooves have a width WC that is 1.6 to 2.0 times the width WA of the center lateral grooves. This local differentiation allows enhanced drainage at the shoulders where water accumulation is most problematic, while preserving sufficient rubber volume and ground contact area in the center region to maintain wear resistance.
2Reliability
If the land ratio of the tread portion is decreased to improve drainage, then wet performance is improved, but the tread portion has reduced actual ground contact area and reduced rubber volume, causing deteriorated wear resistance
Solution Approach 1:
The patent implements local quality by concentrating the groove width increase specifically at the shoulder lateral grooves rather than uniformly across the entire tread. The shoulder lateral groove width WC is set to 1.6 to 2.0 times the center lateral groove width WA, allowing effective water evacuation at the shoulders while preserving rubber volume in the center ground contact area.
3Device complexity
If the axial length of the prior-contacting-side edge of one center block is made shorter than the other, then the tread pattern is simplified, but the block rigidity becomes insufficient and local slippage occurs, leading to uneven wear
Solution Approach 1:
The patent applies asymmetry by making the axial lengths of the prior-contacting-side edges of the center blocks different, with one being longer than the other. This asymmetric configuration creates varying contact sequences that improve water evacuation efficiency while the overall symmetric arrangement of the tread pattern maintains structural balance and prevents excessive complexity.
Solution Approach 2:
The patent changes the parameter of block edge length to optimize performance. By adjusting the axial length of the prior-contacting-side edges of the center blocks to be different, the patent achieves improved water drainage and reduced slippage while maintaining acceptable wear characteristics through careful parameter selection.
4Device complexity
If the angle between the middle main groove and the center lateral groove is acute, then the tread pattern is compact, but water in the center lateral grooves is hard to be discharged to the middle main groove, reducing wet performance
Solution Approach 1:
The patent addresses the drainage issue by utilizing the width dimension of the lateral grooves. By significantly increasing the width WC of the shoulder lateral grooves to 1.6 to 2.0 times the center lateral groove width WA, the patent creates additional cross-sectional area for water flow, enabling effective water discharge even when the grooves intersect at acute angles.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A pneumatic tire 1 is provided in a tread portion 2 with center blocks 22 divided by a center main groove 10, middle main grooves 11, and center lateral grooves 21; middle blocks 32 divided by the middle main grooves 11, shoulder main grooves 12, and middle lateral grooves 31; and shoulder blocks 42 divided by the shoulder main grooves 12, tread edges Te, and shoulder lateral grooves 41. The groove width WA of the center lateral grooves 21 is equal to the groove width WB of the middle lateral grooves 31. The ratio WC/WA of the groove width WC of the shoulder lateral grooves 41 and the groove width WA of the center lateral grooves 21 is 1.3 to 2.3.