Tire Tread Sipe Depth Layout at Sector Boundaries
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing pneumatic tires with numerous sipes in the tread portion face issues of poor appearance due to mold and tread rubber bonding, which compromises braking performance on wet and snow-covered surfaces.
Innovation Solution
A pneumatic tire design featuring shallow bottom sipes in the boundary region between sectors, with specific depth and orientation, to enhance braking performance without altering the tire's appearance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a large number of sipes are disposed in the tread portion to enhance braking performance on wet and snow-covered surfaces, then braking performance is improved, but bonding between the tire mold and tread rubber occurs causing poor appearance
Solution Approach 1:
The patent applies local quality by differentiating sipe depth based on location. Sipes in the boundary region (within 15mm of sector dividing positions) have reduced depth (30%-80% of regular sipe depth), while sipes in other regions maintain full depth. This localized modification prevents mold bonding in critical areas while preserving braking performance in functional areas.
Solution Approach 2:
The patent segments the tread portion into distinct regions: boundary regions near sector dividing positions and non-boundary regions. By applying different sipe depth characteristics to different segments, the solution resolves the contradiction between appearance (affected by mold bonding in boundary regions) and braking performance (dependent on overall sipe density).
2Shape
If the number of sipes is reduced or sipe length is shortened to prevent mold bonding, then appearance is improved, but braking performance on wet and snow-covered surfaces deteriorates
Solution Approach 1:
Instead of uniformly reducing sipes across the entire tread, the patent applies local quality by maintaining full sipe depth in non-boundary regions where braking performance is critical, while only modifying sipe depth in boundary regions where appearance issues occur during molding.
Solution Approach 2:
The patent applies partial action by modifying sipe characteristics only in specific boundary regions rather than across the entire tread. This partial modification is sufficient to prevent mold bonding and improve appearance while leaving the majority of sipes intact to maintain braking performance.
3Shape
If shallow bottom sipes are provided in the boundary region, then mold bonding is suppressed and appearance is improved, but the complexity of sipe depth control increases
Solution Approach 1:
The patent applies parameter changes by modifying the depth parameter of sipes based on their location. The sipe depth parameter is changed from full depth to reduced depth (30%-80%) specifically in boundary regions, while remaining unchanged in other regions. This parameter-based differentiation resolves the contradiction without requiring complex structural modifications.
Data Source
AI summary
A pneumatic tire includes a tread portion molded by sectors divided in a tire circumferential direction. The pneumatic tire includes circumferential grooves, rows of land portions, and sipes. The circumferential grooves extend in the tire circumferential direction in the tread portion. The rows of land portions are defined by the circumferential grooves. The sipes extend in a tire width direction in at least one row of the rows of land portions. The sipes include at least one shallow bottom sipe and regular sipes. The at least one shallow bottom sipe is disposed in a boundary region including a dividing position of each of the sectors. The regular sipes are disposed at positions more separated from the dividing position of each of the sectors than the at least one shallow bottom sipe. The at least one shallow bottom sipe is shallower than the regular sipes.