Tyre Sidewall and Crown Reinforcement for Shock-Resistant Endurance
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Solution Overview
Problem
Heavy-duty tires face challenges in maintaining endurance and resistance to shocks and curbs, particularly when driving on stony ground, due to increased mass and manufacturing costs associated with additional reinforcing layers, which can lead to premature wear and reduced performance.
Innovation Solution
A tire design featuring a radial carcass reinforcement with a single layer of reinforcing elements, including two working crown layers with angles greater than 8° relative to the circumferential direction, and at least one layer of circumferential reinforcing elements, optimized for a 15° drop center rim, with a specific profile that reduces the number of layers while enhancing angular stability and deformation homogeneity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If additional reinforcing layers are added to improve endurance and resistance to shocks, then the tire's strength and reliability improve, but the tire's mass and manufacturing costs increase
Solution Approach 1:
The patent changes the angular parameters of the reinforcing elements. The first working crown layer has elements at angles between 10°-20° with the circumferential direction, while the second working crown layer has elements at angles between 20°-30°. This angular differentiation optimizes the distribution of mechanical stresses without requiring additional layers, thereby maintaining reliability while controlling weight.
Solution Approach 2:
The patent employs a composite reinforcement structure with two distinct working crown layers using metallic cables or wires with different angular orientations. This composite arrangement creates a synergistic effect where the crossed layers together resist both radial and tangential stresses more effectively than a single layer could, achieving enhanced durability without proportional weight increase.
2Strength
If the number of reinforcing layers is increased to resist shocks and curbs, then the tire's strength improves, but the manufacturing complexity and costs increase
Solution Approach 1:
The patent segments the crown reinforcement into two distinct working layers with different angular orientations. The first layer (10°-20°) primarily resists circumferential stresses, while the second layer (20°-30°) provides additional support against radial impacts. This segmentation allows each layer to be optimized for specific stress types, achieving comprehensive shock resistance through a manageable two-layer structure rather than a complex multi-layer system.
3Duration of action of moving object
If the tire construction is optimized for heavy loads and high speeds, then the endurance improves, but the tire becomes more susceptible to damage from curbs and stony ground
Solution Approach 1:
The patent applies local quality by creating heterogeneous reinforcement layers with different angular characteristics. The first working crown layer (10°-20°) is optimized for circumferential stress resistance during high-speed operation, while the second working crown layer (20°-30°) provides enhanced protection against radial impacts from curbs and stones. This local differentiation of reinforcement properties allows the tire to simultaneously withstand both operational stresses and external impacts.
Data Source
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AI summary
The invention relates to a tyre having a radial carcass reinforcement made up of a single layer of reinforcing elements anchored in each of the beads by being turned up around a bead wire, reinforced by a stiffener. According to the invention, the two working crown layers are only present so as to form the crown reinforcement over at least 75% of the width of the tread, the absolute value of the difference between the absolute values of the angles α2 and α1 being greater than 7°, α2 being larger than α1 in terms of absolute value, the mean angle α satisfying the relationship 13+131*exp(- L/100) < α < 28+110*exp(-L/100), the reinforcing elements of the carcass reinforcement being cords having, in the test known as the permeability test, a flow rate of less than 20 cm3/min, a rubber compound being present within the cords and, in the sidewall of the tyre, the profile of the outer surface of the tyre is at a constant distance from the carcass reinforcement layer between the points F and A, and meets the outer surface of the bead at the point C, forming two successive circular arcs.