Three-Layer Tire Crown Reinforcement Against Tread Separation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Radial tires for heavy-duty construction vehicles face premature tread separation when encountering sharp stones, due to the protective reinforcement almost entirely blocking crack spread, leading to potential separation between the tread and the protective reinforcement.
Innovation Solution
A radial tire design with a crown reinforcement comprising three protective layers, where the radially innermost and outermost layers have specific angle relationships and elastic metal reinforcers with varying diameters and spacings, and an intermediate layer with identical reinforcers to the outermost layer, to reduce tread separation risk and enhance cracking resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the protective reinforcement blocks crack spread completely, then crack propagation is prevented, but tread separation occurs due to stress concentration at the tread-protective reinforcement interface
Solution Approach 1:
The protective reinforcement is segmented into multiple layers (first protective layer at 33°, second protective layer at -33°, and intermediate protective layer at -45°) with different orientations. This segmentation allows each layer to handle cracks in different directions while the intermediate layer at steeper angle provides a transition zone that redistributes stress, preventing complete blockage that would cause tread separation.
Solution Approach 2:
The intermediate protective layer is positioned specifically between the first and second protective layers with a distinct orientation angle of -45° (steeper than the outer layers). This local differentiation creates a gradient structure where the intermediate layer provides localized stress redistribution at the critical interface zone, allowing crack resistance while maintaining tread attachment reliability.
2Strength
If the protective reinforcement uses steep angle layers to resist cracking, then cracking resistance improves, but the tire loses flexibility to deform and absorb obstacles
Solution Approach 1:
The protective reinforcement uses a dynamic multi-angle configuration where the intermediate layer at -45° works in conjunction with the outer layers at ±33°. This dynamic angular distribution allows the structure to adapt its resistance characteristics based on crack direction and magnitude, providing cracking resistance while maintaining the flexibility needed to deform over obstacles through coordinated layer interaction.
Solution Approach 2:
The protective reinforcement functions as a composite structure with three layers having different orientation angles (33°, -33°, and -45°). This composite arrangement combines the cracking resistance of steep-angle layers with the flexibility of the overall multi-layer system, where each layer contributes differently to the mechanical response, achieving both protection and adaptability.
3Adaptability or versatility
If the protective reinforcement uses shallow angle layers to maintain flexibility, then obstacle absorption improves, but cracking resistance decreases
Solution Approach 1:
The protective reinforcement segments the crack resistance function across three layers with different angles. The intermediate layer at -45° specifically addresses crack resistance in directions that the shallower outer layers (±33°) cannot effectively handle, while all layers collectively maintain flexibility for obstacle absorption through their coordinated geometric arrangement.
Solution Approach 2:
The intermediate protective layer provides localized enhancement of crack resistance at the specific orientation of -45°, complementing the obstacle-absorption capability of the outer layers. This local quality differentiation allows the system to achieve both cracking resistance and flexibility simultaneously, with each layer optimized for specific functional requirements.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The additional intermediate protective layer and optimized angle relationships between the layers improve the tire's resistance to tread separation and cracking, allowing deformation to absorb obstacles while maintaining sufficient stiffness, as demonstrated by improved indentation stiffness and finite-element calculations.
Implementation Method 1
comprising elastic metal reinforcers having a tensile elastic modulus at most equal to 150 GPa
Data Source
AI summary
A radial tire (1) for a heavy-duty vehicle of construction plant type, and to reduce the risk of tire tread separation when running over sharp stones, while at the same time ensuring that the crown reinforcement exhibits good resistance to cracking. The tire (1) has a protective reinforcement (50) having three protective layers (51, 52, 53), comprising metal reinforcers that respectively have a diameter (D1, D2, D3) and are distributed at an axial spacing (P1, P2, P3). According to the invention, with Alpha1, Alpha2 and Alpha3 being the angles of the reinforcers of the respective layers (51, 52, 53) with the circumferential direction, the following relationships are satisfied:15°≤|Alpha1|≤40°15°≤|Alpha2|≤40°Alpha1*Alpha2≤035°≤|Alpha3|≤75°As regards the differences between the angles of the reinforcers of the protective layers, the following relationship in terms of absolute values applies:|(Alpha1−Alpha3)|≥10°|(Alpha2−Alpha3)|≥10°.