Air Tyre Softened Carcass Reinforcement
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Solution Overview
Problem
Current heavy-duty vehicle tires face challenges in maintaining endurance and wear performance under various conditions, including high-speed travel and overload, due to stresses and temperature-related issues that lead to cracks and fatigue in the crown reinforcement.
Innovation Solution
A tire design with a radial carcass reinforcement featuring at least two working crown layers crossed at angles between 10° and 45°, covered by a tread, and including additional circumferentially oriented reinforcing elements in the shoulders, with metallic cables of diameters less than 0.85 mm and a specific layer configuration to enhance endurance and wear resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the carcass reinforcement uses thicker cables to increase strength, then the tire can withstand higher loads, but the tire weight increases and flexibility decreases
Solution Approach 1:
The patent changes the physical parameters of the carcass reinforcement cables, specifically using cables with diameter less than 0.85mm (preferably 0.60-0.80mm) and wire diameters less than 0.16mm (preferably 0.10-0.15mm). This parameter optimization achieves the required strength while reducing weight compared to conventional thicker cables.
Solution Approach 2:
The patent employs composite construction where the carcass reinforcement uses cables with multiple wire layers (1-4 inner layer wires surrounded by 5-12 intermediate layer wires, optionally with 8-20 outer layer wires). This composite cable structure provides high strength-to-weight ratio, allowing the tire to meet strength requirements without excessive weight.
2Reliability
If additional circumferential reinforcing elements are added to the shoulders, then the tire resistance to cyclic stresses improves, but the device complexity increases
Solution Approach 1:
The patent applies local quality by placing circumferential reinforcing elements specifically in the shoulder regions where cyclic stresses are most severe. This targeted approach enhances reliability at critical locations without adding complexity throughout the entire tire structure. The circumferential elements are positioned at angles between -2.5° and +2.5° relative to the circumferential direction in the shoulder zones.
3Speed
If the cable diameter is reduced to improve flexibility and reduce weight, then the tire can travel at higher speeds with less wear, but the cable strength decreases
Solution Approach 1:
The patent uses composite cable construction with multiple wire layers to maintain strength while reducing overall cable diameter. The carcass reinforcement cables have diameter less than 0.85mm with a specific multi-layer wire structure that provides high strength-to-diameter ratio, enabling high-speed travel without sacrificing cable strength.
Solution Approach 2:
The patent optimizes cable parameters by specifying diameter less than 0.85mm and wire diameters less than 0.16mm, with controlled numbers of wires per layer. This parameter optimization achieves the right balance between flexibility (for high-speed performance) and strength (for load-bearing capability).
Data Source
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AI summary
The invention relates to an air tyre comprising a crown reinforcement (4) made of at least two crown working layers (41, 43) of reinforcement elements. The air tyre further comprises, in each shoulder, at least one end of a layer (43) of reinforcement elements, which elements are parallel to each other in said layer and oriented circumferentially, said end being axially on the outside of the at least two crown working layers (41, 43), the reinforcement elements of the carcass reinforcement (2) having a diameter smaller than 0.85 mm, and said reinforcement elements of the carcass reinforcement being made of wires with a diameter smaller than 0.16 mm.