Tyre Bead Sipe Structure for Heavy-Load Wear Resistance
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Solution Overview
Problem
Heavy-duty tires face challenges in wear resistance and design complexity due to the presence of reinforcing elements like stiffeners, which complicate the tire design and lead to premature wear and deformation, especially during heavy load carrying.
Innovation Solution
The introduction of radially oriented notches on the tire bead, which extend from the radially inner to the outer limit, providing a curvilinear length that optimizes wear resistance by reducing the need for additional stiffeners and simplifying the tire design, while maintaining endurance performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If layers of reinforcing elements (stiffeners) are added to the bead area, then wear resistance and protection against deformation are improved, but device complexity and design complexity increase
Solution Approach 1:
The patent extracts the reinforcing function from complex multi-layer stiffener structures and concentrates it into a single axially outermost reinforcement layer. This layer is positioned to extend from the bead core through the protective layer, providing the necessary mechanical reinforcement while eliminating the complexity of multiple separate reinforcing layers and their interconnections.
Solution Approach 2:
The axially outermost reinforcement layer serves multiple functions simultaneously: it reinforces the bead structure, protects against wear, prevents permanent deformation during dynamic creep, and eliminates the need for separate stiffener layers. This multi-functional design simplifies the overall bead construction while maintaining all necessary protective functions.
2Reliability
If multiple layers of reinforcing elements are used, then protection against premature wear and permanent deformation is improved, but the tire design becomes more complex requiring rubbery mixtures to separate layer ends
Solution Approach 1:
The patent removes the complex multi-layer arrangement and replaces it with a single axially outermost reinforcement layer that extends continuously through the protective layer. This eliminates the need for rubbery mixtures to separate layer ends and simplifies the manufacturing process while maintaining protective functionality.
Solution Approach 2:
The patent merges the functions of multiple reinforcing layers into a single continuous reinforcement layer that extends from the bead core through the protective layer. This consolidation eliminates the need for separate layers and the complex arrangements required to position and connect multiple reinforcing elements.
3Reliability
If the bead structure is reinforced with multiple layers, then endurance performance is improved, but the tire weight increases
Solution Approach 1:
The patent extracts the essential reinforcing function and concentrates it in a single axially outermost reinforcement layer, eliminating the excess weight of multiple redundant reinforcing layers while maintaining the necessary mechanical strength and endurance performance.
Solution Approach 2:
The patent optimizes the parameters of the single reinforcement layer, including its position (axially outermost), extent (through the protective layer), and configuration, to achieve the necessary mechanical performance with minimum material usage, thereby reducing weight while maintaining endurance.
Data Source
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AI summary
The invention relates to a tyre (1) in which each bead (3) has notches (5) of thickness "T" arranged at a circumferential pitch "P", said notches (5) extending substantially perpendicularly to the contact surface (30) to a depth "D" greater than 3 mm, said notches extending radially from a radially inner limit (51) and a radially outer limit (52), the curvilinear length between the radially inner limit (51) and the radially outer limit (52) being "H", an intermediate point (50) being, in a meridian section of the tyre mounted on a rim, inflated to nominal pressure and loaded at twice its nominal load-bearing capacity, situated at half the curvilinear distance between the long contact point (50a) with the rim at a first azimuth corresponding to the centre of the contact patch (20) of the tyre (1) with the ground and the short contact point (50b) with the rim at a second azimuth situated 180° from the first azimuth (A1), the curvilinear length between the long contact point (50a) and the short contact point (50b) being "HB", said radially inner limit (51) being situated radially towards the inside with respect to said intermediate point (50) by a value "H1" with H1=HB/2+B, where B is between 125% of the pitch P and 250% of the pitch P, as far as a radially outer limit (52) situated radially above the intermediate point (50) by a value "H2" with H2=HB/2+B, the pitch P being between 0.8*H and 2.5*H and H=H1+H2.