Pneumatic Tire Shoulder Concave Contour Radius
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Solution Overview
Problem
Existing pneumatic vehicle tires face challenges in reducing rolling resistance while maintaining other performance properties such as cornering stability and load handling.
Innovation Solution
The tire design features a concave contour section in the tire shoulder that extends from the tread's outer contour to the sidewall, formed by a circular arc with a radius of 8-25 mm, which transitions into a convex contour, optimizing the ground contact area and pressure distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the outer contour of the tire shoulder is convex (prior art design), then the tire structure is simple and manufacturing is easy, but the real contact area with the ground is limited and rolling resistance is high
Solution Approach 1:
The patent applies curvature by introducing a concave contour section with a specific radius (8-25 mm) in the tire shoulder area. This concave curvature creates a wider ground contact area by allowing the tread outer contour to extend to points P_TW, thereby reducing rolling resistance through improved pressure distribution while maintaining manufacturability through a defined geometric form.
2Loss of energy
If the tread width is increased to improve ground contact area, then rolling resistance decreases, but the tire volume and material requirements increase
Solution Approach 1:
The patent applies local quality by introducing a concave contour section specifically in the tire shoulder area rather than uniformly increasing the entire tire volume. This localized geometric modification allows the tread outer contour to extend to points P_TW, creating a wider ground contact area where needed while maintaining the original tire volume and material requirements elsewhere.
3Area of stationary object
If the outer contour of the tread extends beyond the conventional convex shoulder contour, then the real contact area increases and pressure distribution improves, but the tire sidewall structure becomes more complex
Solution Approach 1:
The patent resolves the shape complexity issue by defining a specific concave contour section with a radius of 8-25 mm. This mathematically defined curvature creates a smooth transition that allows the tread outer contour to extend to points P_TW, increasing the ground contact area while maintaining a manufacturable and structurally sound shoulder contour shape.
Data Source
Figure 1~2
AI summary
The invention relates to a radial-type pneumatic tire (1) for passenger cars, comprising a tread (2) and a tire shoulder (3) arranged at the transition to the tire sidewall (4), wherein the tread (2) and the tire shoulder (3) have an outer contour to be measured on the mounted and inflated tire (1) and have a width of the tread (2) which is called TW45 and which extends between two points PTW, each of which points PTW is the intersection of a tangent (t) running at 45° to the radial on the outer side of the shoulder with a curve (k) extending in extension of the outer contour of the tread (2).The curve (k) extending from the outer contour of the tread (2) forms the outer contour of the tire shoulder (3) and extends to point PTW and from there transitions towards the tire sidewall (4) into a concave contour section, which is formed by a circular arc section with a radius (R1) in a range of 5-40 mm and which then connects tangentially to the convex outer contour of the tire shoulder (3).