Studless Tire Tread Groove Layout for Pressure and Drainage Balance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Studless tires with sipes separated in the tire width direction face issues with increased local ground contact pressure, degrading load durability and drainage performance.
Innovation Solution
Incorporating circumferential main grooves, lug grooves, and blocks defined by these grooves, with sipes on both sides of the circumferential narrow grooves, and varying groove depths and shapes to distribute ground contact pressure and enhance block rigidity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If sipes in the same block are disposed separated in the tire width direction, then block rigidity is ensured and snow or ice clogging in the sipe is prevented, but ground contact pressure increases locally degrading load durability performance
Solution Approach 1:
The groove depth is varied locally within the circumferential groove: a shallow bottom portion is provided at both end portions of the groove, and a deep bottom portion is provided in a central portion of the block in the tire circumferential direction. This local variation in groove depth allows the central portion to reduce ground contact pressure and improve load durability, while the end portions maintain sufficient contact pressure for block rigidity.
2Strength
If sipes in the same block are disposed separated in the tire width direction, then block rigidity is ensured, but drainage performance deteriorates
Solution Approach 1:
The circumferential groove is designed with different groove depths at different locations: the deep bottom portion in the central portion of the block provides enhanced drainage capability, while the shallow bottom portions at the end portions maintain block rigidity. This local differentiation resolves the contradiction between rigidity and drainage performance.
Data Source
AI summary
A tire including, in a tread surface (12), a plurality of shoulder main grooves extending in a tire circumferential direction, a plurality of lug grooves (351) extending in a direction intersecting the shoulder main groove, and a plurality of blocks B defined by the shoulder main grooves and the lug grooves (351). The tread surface (12) of the block B includes circumferential narrow grooves (352) each extending in the tire circumferential direction and a plurality of sipes that are provided on both sides of the circumferential narrow grooves in a tire width direction so as to be separated from the circumferential narrow grooves (352) and are disposed side by side in the tire circumferential direction and extend in the tire width direction. The circumferential narrow groove (352) includes a shallow bottom portion (3521) and a deep bottom portion (3522) having different depths from the tread surface (12). The deep bottom portion (3522) has a depth from the tread surface (12) deeper than a depth of the shallow bottom portion (3521) and is provided in a central portion of the block B in the tire circumferential direction.