Monofilament Belt Layer Layout for High-Speed Tire Durability
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Solution Overview
Problem
Conventional pneumatic tires lack sufficient durability during high-speed running, particularly on expressways where long-distance high-speed travel is common.
Innovation Solution
A pneumatic tire design featuring a belt layer with monofilament cords as reinforcing cords, arranged at specific densities and angles, and a sidewall rubber composition with controlled rigidity, to enhance durability by balancing tread rigidity and impact absorption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional rubber composition technology is used to reduce rolling resistance, then fuel efficiency is improved, but durability during high-speed running deteriorates
Solution Approach 1:
The patent applies parameter changes by precisely controlling the cord arrangement density (ends per 5cm) within specific ranges (40-60 for narrow tires, 60-80 for wide tires) and cord outer diameter (0.15-0.35mm) to optimize the balance between rolling resistance and high-speed durability. This quantitative parameter optimization allows the tire to achieve both low energy loss and high reliability simultaneously
Solution Approach 2:
The patent uses composite materials by combining monofilament cords with specific rubber compositions in the belt layer. The belt layer comprises a carrier cord and monofilament cords arranged in a composite structure, where the monofilament cords provide tensile strength and dimensional stability while the rubber matrix provides flexibility and shock absorption, achieving both fuel efficiency and durability
2Reliability
If the number of monofilament cords is increased to improve tread rigidity, then durability during high-speed running is improved, but rolling resistance increases
Solution Approach 1:
The patent resolves this contradiction through parameter changes by establishing optimal ranges for cord density (ends per 5cm) and cord diameter. Instead of simply increasing cord number, the patent optimizes the combination of cord density and diameter, along with cord angle (15-30 degrees), to achieve the right balance between tread rigidity for durability and flexibility for low rolling resistance
3Reliability
If monofilament cords are densely arranged to enhance tread integrity, then durability is improved, but impact absorption capability deteriorates
Solution Approach 1:
The patent applies local quality by creating different cord arrangement patterns in different regions of the belt layer. The monofilament cords are arranged with specific density ranges that provide sufficient tread integrity while maintaining spaces that allow the rubber matrix to deform and absorb impacts. The cord angle of 15-30 degrees also contributes to local quality optimization for impact absorption
Data Source
AI summary
A pneumatic tire having a side portion and a belt layer, monofilament cords are used as reinforcing cords in the belt layer, and in a tire-radial-direction cross-section of the belt layer, an arrangement number e of monofilament cords per 5 cm in a tire width direction (cords/5 cm) and a tire cross-sectional width Wt (mm) when the tire is installed to a standardized rim and an inner pressure is set to 250 kPa satisfies the following (formula 1) and (formula 2):e/(139.5−0.3Wt)>1 (formula 1)e/(191.5−0.3Wt)<1 (formula 2),