Continuous Curvature Tire Tread Profile Using Spline Control Points
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Solution Overview
Problem
Conventional tire tread profile designs using arcs lead to uneven pressure distributions, particularly high pressures on shoulder ribs, causing fatigue and potential failure, due to varying curvatures at arc intersections.
Innovation Solution
A tire tread profile with a continuous curvature is achieved using a plurality of splines extending between control points, where the curvatures of adjacent splines are equal at each control point, reducing pressure concentrations on the shoulder ribs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If arcs are used to define and model the tread profile, then the tread profile can be designed with multiple segments, but the curvature varies at arc intersections causing uneven pressure distributions
Solution Approach 1:
The patent applies continuous curvature modeling using splines instead of discrete arcs to eliminate curvature discontinuities at intersection points. This ensures smooth transitions and uniform pressure distribution across the tread profile, particularly at shoulder rib regions where arc intersections previously caused stress concentrations.
Solution Approach 2:
The patent changes the mathematical representation from piecewise arc definitions to spline-based continuous curvature functions. This parameter transformation allows for controlled curvature variation throughout the tread profile, eliminating the abrupt curvature changes that occurred at arc intersections and resulting in more uniform pressure distributions.
2Ease of manufacture
If conventional arc-based tread profiles are used, then manufacturing is straightforward, but shoulder ribs experience high contact pressures leading to faster fatigue
Solution Approach 1:
By implementing continuous curvature through spline functions, the patent eliminates the sharp transitions at arc intersections that caused stress concentrations in shoulder ribs. This smooth curvature distribution reduces contact pressures on exterior shoulder rib portions, thereby improving fatigue resistance and overall reliability while maintaining manufacturability through standardized molding processes.
3Shape
If arcs with different curvatures are used at intersections, then the tread profile can accommodate complex geometries, but pressure control at intersection points becomes difficult
Solution Approach 1:
The patent transforms the geometric representation from discrete arcs with fixed curvatures to continuous spline functions where curvature is a controllable parameter. This allows for precise control of pressure distributions at what were previously problematic intersection points, while still accommodating complex tread geometries through the flexibility of spline modeling.
Data Source
AI summary
A tire and a method for forming a tire tread are disclosed. The tire includes a tread defining an inferior tread profile and a superior tread profile, the superior tread profile having a generally continuous curvature between an edge of contact and a top center point. The superior tread profile includes a plurality of control points and a plurality of splines. Each of the plurality of splines extends between at least two of the plurality of control points. Curvatures of adjacent splines are generally equal at each of the plurality of control points.