Pneumatic Tire Bead Area Hardness Gradient
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Pneumatic vehicle tires are prone to mechanical and thermal failure under overload conditions due to uneven stiffness in the bead area, which is exacerbated by additional reinforcing layers that increase rolling resistance.
Innovation Solution
Optimizing the Shore A hardness of existing rubber mixtures in the bead area components to ensure that adjacent components differ by no more than 5 Shore A hardness points, with a gradual increase or decrease from the bead core apex to the sidewall, eliminating the need for additional reinforcement layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If additional reinforcing layers are introduced into the bead area to prevent mechanical failure under overload conditions, then the strength and durability of the bead area is improved, but the rolling resistance of the tire increases
Solution Approach 1:
The invention changes the physical parameter of rubber mixture hardness (Shore A hardness) in the bead area components. By optimizing the hardness values and ensuring they differ by no more than 5 Shore A points, the invention achieves improved strength without adding reinforcing layers, thus avoiding increased rolling resistance.
Solution Approach 2:
The invention applies local quality by giving specific hardness characteristics to different components in the bead area (bead core apex, bead strips, cushion strips, bead reinforcers) while maintaining overall uniformity. Each component has an optimized hardness value tailored to its specific function and position, creating a locally optimized structure that prevents failure without requiring additional reinforcement.
2Duration of action of stationary object
If additional reinforcing layers are introduced into the bead area to prevent mechanical failure, then the durability of the tire is improved, but the risk of thermal-related tire failure increases
Solution Approach 1:
The invention changes the hardness parameter of existing rubber mixtures in the bead area components to achieve better durability. By optimizing the Shore A hardness values and ensuring uniform distribution (differing by no more than 5 points), the invention improves durability while avoiding the thermal risks associated with additional reinforcing layers.
3Reliability
If the Shore A hardness of components in the bead area is optimized to differ by no more than 5 Shore A points, then the stiffness jumps are reduced and load distribution is improved, but the complexity of manufacturing precision increases
Solution Approach 1:
The invention specifies a quantitative parameter range (Shore A hardness difference of no more than 5 points) that balances manufacturing feasibility with performance optimization. This parameter control ensures reliable load distribution while remaining practical for manufacturing processes.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Vehicle pneumatic tire for a passenger car, van or light truck with a radial carcass (3, 3a, 14) and with two bead areas (11), each comprising at least one bead core (4), a bead core rider (5) seated on the bead core (4) and a bead strip (13) limiting the bead area (11) axially outwards, wherein the radial carcass (3, 14) is guided from axially inside to axially outside around the bead cores (4) and terminates in a carcass high point (3a) and wherein the components arranged in the bead area (11) bead core rider (5), radial carcass (3, 3a, 14) and bead strip (13) have certain Shore A hardnesses. To improve the durability of the bead area, the Shore A hardness of components (3, 3a, 14, 12, 13, 14, 15) arranged axially adjacent in the bead area (11) does not deviate from each other by more than 5 Shore A hardness points.