Passenger Tyre Tread Reinforcement for Grip and Wear
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Solution Overview
Problem
Current passenger tires face challenges in achieving improved longitudinal and transverse grip on wet and dry surfaces while maintaining performance at low transverse acceleration and wear levels, while also reducing mass and rolling resistance.
Innovation Solution
The tire design incorporates a tread with a specific elastomeric mixture, a hooping reinforcement with aromatic polyamide textile reinforcements, and working layers with steel monofilaments at optimized angles and densities, along with an intermediate elastomeric layer to enhance grip, wear resistance, and reduce mass.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the tread volume notch rate is increased to improve grip, then longitudinal and transverse grip on wet and dry surfaces is improved, but the tread height must be reduced to maintain wear performance
Solution Approach 1:
The patent changes the volumetric notch rate parameter from conventional values (30-32%) to a specific range (20-29%), and adjusts the tread height parameter to (6.0-7.6mm). These parameter changes optimize the balance between grip performance and wear resistance without sacrificing either property.
Solution Approach 2:
The patent uses a specific elastomeric mixture composition with controlled glass transition temperature (-18°C to -6°C), Shore A hardness (60-75), and loss at 60°C (24%-35%). This composite material formulation enables the tread to achieve both improved grip and reduced wear simultaneously.
2Reliability
If aromatic polyamide textile reinforcements are used in the hooping layer to improve grip and reduce mass, then longitudinal and transverse grip is improved and tire mass is reduced, but manufacturing complexity increases
Solution Approach 1:
The patent specifies precise parameters for the aromatic polyamide textile reinforcements including orientation angles (α1, α2) within (20°-40°), density (100-200 wires/dm), and layer thickness (D+0.1mm to D+0.6mm). These controlled parameters ensure optimal grip performance while maintaining manufacturability through standardized specifications.
3Reliability
If steel monofilament reinforcements with optimized density and orientation are used in working layers, then grip and behavior at low transverse acceleration are improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent defines specific parameter ranges for steel monofilament reinforcements including orientation angles (25°-40°), density (100-200 wires/dm), and layer thickness (D+0.1mm to D+0.6mm). These ranges provide sufficient design freedom for manufacturing while ensuring optimal grip and low-speed cornering behavior.
4Use of energy by moving object
If tire mass is reduced through optimized reinforcement structure to improve fuel efficiency, then rolling resistance and fuel consumption are improved, but strength and durability must be maintained
Solution Approach 1:
The patent employs a composite reinforcement structure combining aromatic polyamide textile reinforcements in the hooping layer with steel monofilament reinforcements in the working layers. This composite approach reduces overall tire mass and rolling resistance while maintaining structural strength and durability through the complementary properties of different materials.
Solution Approach 2:
The patent applies different reinforcement types and densities in different tire regions - aromatic polyamide in the hooping layer for circumferential strength and steel monofilaments in working layers at specific angles for lateral stability. This localized optimization reduces mass where possible while maintaining strength where required.
Data Source
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AI summary
The invention aims to improve the grip of a passenger tyre (1), without degrading the behaviour, wear and endurance thereof and while decreasing the weight. According to the invention, the tread (2) has a volumetric void ratio VVR at least equal to 20% and at most equal to 29% and a ¾ radial height at least equal to 6.0 mm and at most equal to 7.6 mm, and comprises an elastomeric mixture having a glass transition temperature Tg at least equal to -18°C and at most equal to -6°C, a Shore A hardness at least equal to 60 and at most equal to 75 and a loss at 60°C at least equal to 24%> and at most equal to 35%>. Finally, the metal reinforcers of the working layers (41, 42) are steel monofilaments having a section S with the smallest dimension Dmin thereof at least equal to 0.20 mm and at most equal to 0.50 mm, distributed according to a density di at least equal to 100 threads/dm and at most equal to 200 threads/dm, each working layer (41, 42) having a mean radial thickness ET at least equal to D+0.1 mm and at most equal to D+0.6 mm, with D the diameter of the circle delimited by the section S of the reinforcer.