Heavy-Duty Tyre Tread Oblique Cutouts Wear Resistance
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Solution Overview
Problem
Current heavy-duty tires face issues with wear regularity and rolling resistance, particularly with oblique cutouts on the tread, leading to irregular wear patterns and increased fuel consumption due to inefficient rolling resistance.
Innovation Solution
A tire design with a radial carcass reinforcement featuring a crown reinforcement structure that includes at least two working crown layers with calendered rubber mixtures, a layer of circumferential reinforcing elements, and oblique cutouts with specific depth and width ratios, along with a layer of circumferential reinforcing elements to manage shear stresses and deformations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If oblique cutouts are introduced on the tread to improve rolling resistance, then fuel efficiency is improved, but wear regularity deteriorates
Solution Approach 1:
The patent applies local quality by varying the depth of oblique cutouts across different regions of the tread. The cutouts have different depths in the central portion versus the lateral portions, allowing each region to have optimized characteristics for its specific function while maintaining overall wear regularity and fuel efficiency
Solution Approach 2:
The tread is segmented into different zones (central portion and lateral portions) with distinct cutout depth characteristics. This segmentation allows independent optimization of each zone's wear pattern and rolling resistance properties, preventing the wear irregularities that would occur with uniform cutouts
2Use of energy by moving object
If the depth of oblique cutouts is increased to reduce rolling resistance, then fuel consumption is reduced, but tread structural integrity deteriorates
Solution Approach 1:
Different cutout depths are applied to different tread regions: deeper cutouts in the central portion for optimal rolling resistance, and shallower cutouts in lateral portions to maintain structural integrity and prevent excessive deformation, thus balancing fuel efficiency with tread strength
Solution Approach 2:
The patent changes the depth parameter of cutouts based on location, creating a gradient structure that optimizes the balance between rolling resistance reduction and structural integrity maintenance across the tread surface
3Reliability
If calendering mixtures with high cohesion are used to prevent crack propagation, then tire endurance is improved, but rolling resistance increases
Solution Approach 1:
The patent modifies the cohesion parameter of calendering mixtures to an optimal range (5 to 15 MPa) that balances crack resistance with rolling resistance. This parameter optimization allows the tire to maintain durability while achieving lower rolling resistance compared to conventional high-cohesion mixtures
Solution Approach 2:
The patent uses composite calendering mixtures combining rubber compounds with specific cohesion characteristics and reinforcing fillers. These composite materials provide adequate crack propagation resistance while maintaining flexibility and low rolling resistance, overcoming the trade-off between endurance and energy efficiency
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 design enhances wear regularity and reduces rolling resistance, contributing to improved fuel efficiency and extended tire life by controlling deformations and maintaining cohesion of the rubber mixtures.
Implementation Method 1
The modulus of elasticity under tension at 10% elongation of at least one calendering layer of at least one working top layer is greater than 9 MPa and the maximum value of tan(δ), denoted tan(δ)max, of said at least one calendering layer of at least one working top layer is less than 0.100
Implementation Method 2
the maximum value of tan(δ), denoted tan(δ)max, of said at least one calendering layer of at least one working top layer is less than 0.100
Implementation Method 3
a layer of circumferential reinforcing elements, said crown reinforcement comprising at least one layer of circumferential reinforcing elements
Implementation Method 4
having at least in said central part at least one cutout of oblique orientation, the depth, measured on a new tire in at least said central part, of said at least one cutout of oblique orientation being greater than or equal to 40% of the thickness of the tread
Data Source
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AI summary
The invention relates to a tyre including a crown reinforcement formed of at least two working crown plies (41, 43) of reinforcement elements and at least one ply (42) of circumferential reinforcement elements. According to the invention, the tread has at least one cut-out with oblique orientation (7), the depth of said at least one cut-out with oblique orientation, measured on a new tyre, being no lower than 40% of the thickness of the tread, the ratio of the width of said at least one cut-out with oblique orientation, measured at the bottom, to the width of said at least one cut-out with oblique orientation, measured at the surface of the tread, being greater than 1.2, the modulus of elasticity under tension at 10% elongation of at least one liner layer of at least one working crown ply being greater than 9 MPa, and the maximum value of tan(8), noted as tan(8) max, of said at least one liner layer of at least one working crown ply being lower than 0.100.