Tire Tread Segmentation for Winter and Normal Road Performance
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Solution Overview
Problem
Current tire treads fail to maintain simultaneous high performance on both winter and normal roads until close to the end of their wear life, as increased tread stiffness for winter conditions negatively impacts normal road performance.
Innovation Solution
A tread design featuring two rubber layers laminated in radial orientation, with solid particles in the base rubber layer and none in the cap layer, which maintains incision density and stiffness, creating micro-roughness for improved snow and ice traction while preventing premature wear and maintaining normal road performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the number of incisions, closed cell foam or hollow particles in the tread bottom portion is increased to maintain wintry road performance, then snow performance is improved, but normal road performance deteriorates due to excessive softness
Solution Approach 1:
The tread is divided into multiple blocks, and each block is further segmented into a cap rubber layer and a base rubber layer. The incisions are selectively applied only to the base rubber layer blocks, while cap rubber layer blocks remain intact. This segmentation allows different parts of the tread to serve different functions: incised blocks provide snow performance while intact blocks maintain normal road performance and stiffness.
Solution Approach 2:
Different regions of the tread are given different properties: the base rubber layer blocks receive incisions to create micro-roughness for snow traction, while cap rubber layer blocks remain smooth and intact to provide stiffness for normal road performance. This local differentiation resolves the contradiction by applying the incision treatment only where needed for wintry performance without compromising overall tread stiffness.
2Reliability
If double-branched incisions are applied to increase incision density, then wintry road performance is improved, but tread stiffness decreases impacting normal road performance
Solution Approach 1:
The tread surface is segmented into alternating incised blocks and intact blocks. The incised blocks provide snow performance through double-branched incisions, while the intact cap rubber layer blocks maintain overall tread stiffness. This segmentation allows high incision density in specific locations without compromising global structural rigidity.
Solution Approach 2:
The double-branched incisions are applied locally to specific base rubber layer blocks rather than uniformly across the entire tread. This localized application provides snow performance where needed while leaving other areas with full stiffness, resolving the contradiction between incision density and overall tread strength.
3Reliability
If spherical shaped closed cell foam or hollow particles are added to the tread composition, then wintry road performance is improved through micro-roughness, but normal road performance deteriorates due to reduced stiffness from the beginning of tire life
Solution Approach 1:
Instead of using durable but stiff materials throughout the tread, the invention uses hollow particles that are strategically placed only in the base rubber layer blocks that will be incised. These particles provide temporary micro-roughness for snow performance during their service life, while the overall tread structure maintains stiffness through the intact cap rubber layer blocks.
Solution Approach 2:
The tread uses a composite structure combining cap rubber layer and base rubber layer with hollow particles. The cap rubber layer provides stiffness and structural integrity, while the base rubber layer with hollow particles provides snow performance through micro-roughness. This composite approach resolves the contradiction by combining materials with complementary properties in specific locations.
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
Present invention provides a tread (1) for a tire provided with a plurality of grooves (3) and a plurality of contact elements (4), each the contact elements having an incision density DLN when the tread being new and an incision density DLL) when the tread being worn to a predetermined remaining tread depth, the incision density DLN being greater than or equal to the incision density DLL) at the predetermined remaining tread depth, and the incision density DLN being greater than the incision density DLL) at a level of a tread wear indicator (8), the tread comprising at least two rubber layers laminated in radial orientation, the rubber layers comprising a cap rubber layer (6) and a base rubber layer (7) provided radially inward of the cap rubber layer, a rubber composition constituting the base rubber layer comprises solid particles, and the cap rubber layer is devoid of said solid particles.