Tire Sipe Opening Layout for Dry Braking and Steering Stability
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Solution Overview
Problem
The existing tire design, as described in Patent Document 1, experiences reduced contact pressure around the sipes during braking on dry road surfaces, leading to low braking performance.
Innovation Solution
The tire features a tread portion with circumferential grooves and land portions, including first shoulder and middle land portions with sipes. The sipes have a main portion extending radially and a widened portion at the tread surface, with the first shoulder sipes having a larger opening width than the first middle sipes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If sipes are provided in the middle land portion with narrow opening widths (less than 2 mm) to optimize pattern rigidity and improve steering stability, then steering stability is improved, but braking performance on dry road surfaces deteriorates due to local reduction of contact pressure around the sipes
Solution Approach 1:
The patent applies local quality by differentiating the sipe opening widths between different land portions. The first middle land portion (near shoulder) has sipes with opening widths of 1.5-3.0 mm, while the second middle land portion (central) has sipes with opening widths of 0.5-2.0 mm. This localized differentiation allows the shoulder area to maintain better contact pressure for braking while the central area maintains rigidity for steering stability.
2Ease of operation
If the opening edge of the sipe on the leading-edge side is deformed by shearing force during braking, then the edge can be rolled up by shear force, but contact pressure around the sipe is locally reduced, leading to low braking performance
Solution Approach 1:
The patent changes the geometric parameter of sipe opening width to resolve the contradiction. By setting specific opening width ranges (1.5-3.0 mm for first middle land, 0.5-2.0 mm for second middle land), the patent optimizes the balance between allowing sufficient deformation for braking operation and maintaining adequate contact pressure for braking performance.
Data Source
AI summary
A tire comprises a tread portion comprising circumferential grooves and land portions divided thereby. The land portions include a first shoulder land portion and a first middle land portion adjacent thereto. The first shoulder land portion is provided with first shoulder sipes. The middle land portion is provided with first middle sipes. Each of the first shoulder sipes and the first middle sipes comprises a main portion extending in the tire radial direction, and a widened portion having a width greater than the main portion and opened at the tread surface of the land portion. The opening width of the first shoulder sipe at the tread surface is larger than the opening width of the first middle sipe at the tread surface.