Pneumatic Tire Bead Core Wire Winding for Weight Uniformity
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Solution Overview
Problem
Conventional pneumatic tire manufacturing methods using wire wound bead cores result in uneven weight distribution due to the varying radius of curvature of the bead wire, leading to poor uniformity.
Innovation Solution
A pneumatic tire design featuring a wire wound bead core where the bead wire is spirally wound in a continuous manner around the tire rotational axis, forming multiple layers with a first part having a constant radius and a second part with a gradually increasing radius, ensuring the gravity center aligns closer to the winding center, thereby improving weight uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the bead wire is wound with gradually increasing radius of curvature, then the wire wound body can be formed, but the gravity center deviates from the winding center causing poor weight uniformity
Solution Approach 1:
The wire wound body is divided into two distinct parts: a first part with constant radius of curvature and a second part with gradually increasing radius of curvature. This segmentation allows the first part to provide a balanced gravity center aligned with the winding center, while the second part adapts to the tire bead shape, thereby resolving the contradiction between weight uniformity and shape formation.
Solution Approach 2:
Different regions of the wire wound body are given different geometric properties. The first part has constant radius for optimal weight distribution, while the second part has variable radius for proper bead positioning. This local differentiation of geometric quality enables both weight uniformity and correct bead core formation simultaneously.
2Stability of the object's composition
If the bead wire is spirally wound continuously, then the wire wound body structure is formed, but the gravity center position becomes difficult to control
Solution Approach 1:
The continuous spiral winding is segmented into two parts with different geometric characteristics. The first part maintains constant radius to ensure gravity center alignment, while the second part varies the radius. This segmentation of the continuous structure allows both structural integrity and precise gravity center control.
3Shape
If the wire wound body has varying radius, then it can accommodate the bead shape, but the weight distribution becomes uneven
Solution Approach 1:
The wire wound body exhibits local quality variation where the first part has constant radius for weight balance and the second part has variable radius for bead shape accommodation. This localized differentiation of geometric properties allows each region to fulfill its specific function without compromising the other.
Solution Approach 2:
By dividing the wire wound body into two segments with different radius characteristics, the patent enables the first segment to provide weight balance while the second segment provides shape adaptation, resolving the contradiction between these two requirements.
Data Source
Figure 1
Figure 2(a)~2(b)
Figure 3
AI summary
The present invention has an object of providing a pneumatic tire that exhibits better uniformity by improving the wire wound body for constituting the bead core. The pneumatic tire 1 comprises a bead core 5 comprising a wire wound body 10 in which one bead wire 10a is spirally wound in a continuous around a tire rotational axis CL so that a plurality of layers of the bead wire are formed in a radial direction of the tire. The wire wound body 10 comprises a first part 13 and a second part 14. The first part 13 comprises a plurality of layers of the bead wire 10a each circumferentially extending with a constant radius from the tire rotational axis CL. The second part comprises a plurality of layers of the bead wire 10a each circumferentially extending while changing its radius from the tire rotational axis CL.