Tire Carcass Ply and Apex Structure for Cornering Stability
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Solution Overview
Problem
Two-wheeled automotive vehicle tires face challenges in achieving improved cornering stability while maintaining ride comfort, as existing radial tires often compromise on one aspect for the other.
Innovation Solution
A pneumatic tire design featuring a carcass with a first and second carcass ply, where the first carcass ply is turned up around the beads with a tilt angle greater than 60 degrees and the second carcass ply is layered over it, combined with a band having a cord helically wound in the tire circumferential direction, enhances stiffness and cornering force while restraining torsion and maintaining ride comfort through specific apex and bead structure configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the tire uses conventional radial tire structure, then ride comfort is maintained, but cornering stability deteriorates
Solution Approach 1:
The carcass is divided into multiple plies (first carcass ply, second carcass ply, third carcass ply) with different cord arrangements and orientations. The first carcass ply has cords extending in the tire circumferential direction, the second carcass ply has cords extending radially, and the third carcass ply has cords at specific angles, creating segmented functional zones that simultaneously provide cornering stability and ride comfort
Solution Approach 2:
The tire employs composite cord materials including steel cords, organic fiber cords, and aramid cords in different plies and configurations. The band layer uses steel cords for high stiffness, while the carcass plies use organic fibers and aramid for flexibility and comfort, creating a composite structure that balances opposing performance requirements
2Strength
If the tire increases stiffness for cornering performance, then cornering stability improves, but ride comfort deteriorates
Solution Approach 1:
Different regions of the tire are given different structural properties: the band layer provides high stiffness locally under the tread for cornering stability, while the carcass plies with radial and circumferential cord arrangements provide localized flexibility in sidewall regions for ride comfort. The apex structure at the bead region provides localized reinforcement without compromising overall comfort
Data Source
AI summary
A band 12 of a tire 2 includes a topping rubber, and a cord that is helically wound in a circumferential direction of the tire 2. A carcass 10 includes a first carcass ply 22, and a second carcass ply 24 that is layered over the first carcass ply 22, so as to be located outwardly of the first carcass ply 22 in the radial direction. The first carcass ply 22 is turned up around beads 8. The turnup ends 36 are located inwardly of the second carcass ply 24 in an axial direction. A tip of an apex is located inwardly, in the radial direction, of the end of the tread, and outwardly, in the radial direction, of a position that is distant from the end of the tread in the radially inward direction by one-third of a length of the straight line LH.