Pneumatic Tire Sidewall Thickness Ratios for Weight Reduction
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Solution Overview
Problem
The challenge is to reduce the weight of pneumatic tires while preventing the occurrence of bareness, which can result from excessively thin sidewall rubber, leading to air entrapment or rubber flow issues during the vulcanizing process.
Innovation Solution
A pneumatic tire design that decreases the thickness of the sidewall rubber while maintaining adequate thickness to prevent bareness, utilizing a specific tread and sidewall structure with crosslinked rubbers of varying properties to ensure durability and resistance, and optimizing the rubber thickness ratios to balance weight reduction with performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If the thickness of the rubber of each sidewall portion is decreased to reduce tire weight, then the tire weight is reduced, but air may be entrapped or rubber flow may be deteriorated in the vulcanizing process causing bareness
Solution Approach 1:
The patent specifies precise parameter ranges for sidewall rubber thickness (0.8mm to 1.5mm) and establishes mathematical relationships between sidewall thickness and other components (tread thickness ratio: 0.15-0.35, sidewall to belt thickness ratio: 0.40-0.65). By optimizing these parameters, the invention achieves weight reduction while preventing air entrapment and rubber flow deterioration during vulcanizing.
Solution Approach 2:
The patent employs composite rubber formulations with specific compound compositions for different tire components. The sidewall rubber has a distinct compound formulation optimized for thin-section vulcanizing, while the tread and other parts use different formulations. This material differentiation enables successful vulcanizing of thin sidewalls without bareness while maintaining overall tire performance.
2Weight of moving object
If the thickness of the rubber of each sidewall portion is excessively decreased, then the tire weight is reduced, but bareness occurs which impairs the appearance of the tire
Solution Approach 1:
The patent defines a minimum sidewall thickness of 0.8mm and establishes upper limits (1.5mm) to prevent bareness. It also sets specific thickness ratios between sidewall, tread, and belt components to ensure uniform rubber flow and prevent appearance defects. These parameter controls enable weight reduction while maintaining manufacturing precision and appearance quality.
Solution Approach 2:
The patent performs preliminary optimization of the mold design and vulcanizing parameters before production, accounting for the thin sidewall characteristics. By pre-adjusting the vulcanizing conditions and mold geometry to suit thin sidewalls, the invention prevents bareness and appearance defects before they occur during actual manufacturing.
3Weight of moving object
If the thickness of the rubber of each sidewall portion is decreased, then the tire weight is reduced, but the handling performance and ride comfort may be affected
Solution Approach 1:
The patent maintains sidewall thickness within 0.8mm to 1.5mm to achieve weight reduction while preserving handling performance. It establishes specific thickness ratios between sidewall, tread, and belt components to ensure the thin sidewall does not compromise structural integrity or handling characteristics. This parameter optimization allows weight reduction without significant performance degradation.
Solution Approach 2:
The patent uses specialized rubber compound formulations for the thin sidewall that maintain elasticity and damping properties despite reduced thickness. The compound composition is optimized to compensate for the thinner section, ensuring handling performance and ride comfort are preserved even with weight reduction.
Data Source
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AI summary
In a pneumatic tire 2, a ratio Te/Ta of a thickness Te of a rubber of each sidewall 8 at a position where a width of the tire is at its maximum to a thickness Ta of a rubber of a tread 4 at a center thereof is not less than 0.12 and not greater than 0.28. A ratio Te/Tf of the thickness Te to a thickness Tf of a rubber of each clinch 10 is not less than 0.35 and not greater than 0.65. Preferably, a ratio Te/Ti of the thickness Te to a thickness Ti of rubbers at each buttress portion is not less than 0.17 and not greater than 0.37. A ratio Ti/Til of the thickness Ti to a thickness Ti1 of the crosslinked rubber of each sidewall 8 at the thickness Ti is not less than 2.8 and not greater than 5.2. A ratio Ti/Tf of the thickness Ti to the thickness Tf is not less than 1.35 and not greater than 2.35.