Pneumatic Tire Belt Structure Balancing Durability and Weight
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Solution Overview
Problem
The use of steel cords with large filament diameters in tire belt plies increases tire weight and bending rigidity, reducing ground contact area and driving stability.
Innovation Solution
A pneumatic tire design incorporating a belt layer with steel cords arranged at an angle to the tire circumferential direction and a belt reinforcing layer with organic fiber cords, where the filament diameter of the steel cords is between 0.10 mm and 0.25 mm, and specific relationships between bending load, load at 2% elongation, and load at 5% elongation are satisfied.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If steel cords with large filament diameter are used in the belt ply, then high-speed durability is improved, but tire weight increases and bending rigidity increases, reducing ground contact area and driving stability
Solution Approach 1:
The patent optimizes the filament diameter parameter of steel cords to a specific range (0.15mm to 0.25mm) to achieve the best balance between high-speed durability and driving stability. This parameter optimization prevents excessive weight increase while maintaining the necessary strength for high-speed performance.
Solution Approach 2:
The patent uses a composite structure combining steel cords with organic fiber cords in the belt ply. This composite material approach allows the steel cords to provide high-speed durability while the organic fibers help reduce overall weight and maintain flexibility, preventing excessive bending rigidity increase.
2Reliability
If steel cords with large filament diameter are used in the belt ply, then high-speed durability is improved, but bending rigidity increases, reducing ground contact area and driving stability
Solution Approach 1:
The patent optimizes the filament diameter parameter of steel cords to a specific range (0.15mm to 0.25mm) to achieve the best balance between high-speed durability and driving stability. This parameter optimization prevents excessive bending rigidity increase while maintaining the necessary strength for high-speed performance.
Solution Approach 2:
The patent uses a composite structure combining steel cords with organic fiber cords in the belt ply. This composite material approach allows the steel cords to provide high-speed durability while the organic fibers help reduce overall weight and maintain flexibility, preventing excessive bending rigidity increase.
3Reliability
If the number of steel cords in the belt ply is increased, then high-speed durability is improved, but tire weight increases
Solution Approach 1:
The patent optimizes the filament diameter parameter of steel cords to a specific range (0.15mm to 0.25mm) to achieve the best balance between high-speed durability and driving stability. This parameter optimization prevents excessive weight increase while maintaining the necessary strength for high-speed performance.
Solution Approach 2:
The patent uses a composite structure combining steel cords with organic fiber cords in the belt ply. This composite material approach allows the steel cords to provide high-speed durability while the organic fibers help reduce overall weight and maintain flexibility, preventing excessive bending rigidity increase.
Data Source
Figure 1
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AI summary
A pneumatic tire (1) including: a belt layer (20); and a belt reinforcing layer (30), in which: a filament diameter of each of steel cords of belt ply (21) is more than 0.10 mm and less than 0.25 mm; and A, B, and C satisfy relationships represented by the following Expression (I) and Expression (II), B/A<400 600<C/A<2000 where: A [N/inch] is a bending load per unit width of a sheet of the belt ply (21); B [N/inch] is a product of a load at 2% elongation of each of organic fiber cords of belt reinforcing ply (31) [N/cord] and the number of the organic fiber cords [cord/inch]; and C [N/inch] is a product of a load at 5% elongation of each of the organic fiber cords [N/cord] and the number of the organic fiber cords [cord/inch].