Tire Tread Groove Depth Variation for Wet Grip
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional tires with increased groove negative rates for improved drainage performance on wet roads compromise handling and stability due to reduced effective ground contact area and degraded block rigidity.
Innovation Solution
A tire design featuring a circumferential direction main groove with shallow and deep grooved portions, paired with central land portions and supplemental grooves, and sipes that extend to the main groove, enhancing drainage while maintaining stability through restricted movement of central land portions during rotation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the groove negative rate is increased to secure drainage performance, then drainage performance is improved, but the effective ground contact area is decreased and handling-and-stability degrades
Solution Approach 1:
The patent introduces depth as an additional dimension by forming deep grooved portions within the circumferential direction main groove, rather than simply increasing the groove negative rate on the surface. This allows drainage performance to be improved through the depth dimension while maintaining adequate surface contact area for handling and stability.
Solution Approach 2:
The patent applies different groove depths at different locations within the circumferential direction main groove. The deep grooved portions are strategically positioned to provide enhanced drainage in specific areas, while other areas maintain shallower grooves to preserve ground contact area and block rigidity.
2Reliability
If the groove negative rate is increased to secure drainage performance, then drainage performance is improved, but block rigidity degrades and handling-and-stability cannot be secured sufficiently
Solution Approach 1:
Instead of increasing groove negative rate (surface area), the patent utilizes the depth dimension by forming deep grooved portions that extend deeper into the tread. This provides effective drainage pathways without compromising the surface area and rigidity of the tread blocks.
Solution Approach 2:
The circumferential direction main groove is segmented into multiple deep grooved portions positioned at different locations. This segmentation allows drainage functionality to be distributed throughout the groove structure, providing effective water evacuation while maintaining overall block integrity and rigidity.
3Reliability
If sipes are extended to divide blocks into small pieces to improve drainage, then drainage performance is improved, but block rigidity degrades
Solution Approach 1:
The patent shifts the drainage enhancement approach from dividing blocks with sipes (surface level) to creating deep grooved portions within the circumferential direction main groove (depth level). This provides effective drainage pathways without fragmenting the tread blocks and compromising their rigidity.
Data Source
AI summary
A tire includes a circumferential direction main groove on a tread surface, first and second circumferential supplemental grooves located on both sides of the circumferential direction main groove, and first and second central land portions formed between the circumferential direction main groove and the first and second circumferential direction supplemental grooves. The first and second central land portions have plural width direction sipes, respectively, and each of the width direction sipes extends to the circumferential main groove, the circumferential main groove has shallow grooved portions and deep grooved portions. The deep grooved portions are deeper than the shallow grooved portions, and the shallow grooved portions are shallower than the circumferential supplemental grooves.