Tread Rubber Composition for High-Speed Tire Noise Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional pneumatic tire noise reduction technologies are insufficient for high-speed running, especially at speeds of 80 km/h or higher, particularly in electric vehicles where tire noise becomes a dominant issue.
Innovation Solution
A pneumatic tire design featuring a tread portion with an outermost layer made of a rubber composition containing vulcanized rubber powder, with specific loss tangent and area ratio characteristics, and a thickness that enhances energy absorption and noise reduction, potentially combined with silica and multiple rubber layers for improved noise performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional tread designs are used, then manufacturing simplicity is maintained, but noise performance during high-speed running is insufficient
Solution Approach 1:
The tread portion is designed with an outermost layer that has different properties from the inner layers. This outermost layer contains vulcanized rubber powder and has a loss tangent of 0.30 or more, which is specifically engineered to reduce noise during high-speed running. The localized application of this special rubber composition at the tread surface allows noise reduction without complicating the overall tire structure.
Solution Approach 2:
The outermost layer of the tread portion uses a composite rubber composition that includes vulcanized rubber powder mixed with uncured rubber. This composite material structure provides both the noise reduction properties (through the vulcanized rubber powder with specific loss tangent) and the structural integrity needed for tire performance. The combination of different material states (vulcanized and uncured rubber) creates a functional composite that addresses noise issues without excessive structural complexity.
2Object-affected harmful factors
If the outermost layer thickness is increased to improve noise absorption, then noise performance improves, but the tire weight increases
Solution Approach 1:
The invention specifies that the loss tangent of the rubber composition in the outermost layer should be 0.30 or more. This parameter change in the rubber material properties enables effective noise absorption at the specified thickness (5-15 mm). By optimizing the rubber composition parameters (particularly the loss tangent through inclusion of vulcanized rubber powder), the design achieves adequate noise absorption without requiring excessive thickness that would increase weight.
3Object-affected harmful factors
If vulcanized rubber powder content is increased to enhance noise reduction, then noise performance improves, but manufacturing precision requirements increase
Solution Approach 1:
The invention specifies that the area ratio of vulcanized rubber powder should be 5% to 50% of the total cross-sectional area of the outermost layer. This range provides sufficient noise reduction effect without requiring extremely precise control of the powder distribution. The upper limit of 50% ensures that even with variation in manufacturing, the noise reduction performance remains adequate, while the lower limit of 5% ensures minimum effectiveness. This partial action approach balances noise reduction with manufacturing feasibility.
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 tire achieves significant noise performance improvement during high-speed running by effectively absorbing energy and reducing sound generation, maintaining durability and noise reduction at speeds of 80 km/h or higher.
Implementation Method 1
a loss tangent (0°C tanδ) of greater than 0.30 as measured under conditions of 0°C, a frequency of 10 Hz, an initial strain of 5%, and a dynamic strain rate of 1% with deformation mode: tension
Data Source
AI summary
A pneumatic tire includes a tread portion, an outermost layer of the tread portion is formed by using a rubber composition, which contains vulcanized rubber powder and has a loss tangent (0°C tanδ) of greater than 0.30 as measured under conditions of 0°C, a frequency of 10 Hz, an initial strain of 5%, and a dynamic strain rate of 1% with deformation mode: tension, such that a thickness G (mm) at a crown portion of the outermost layer is greater than 5 mm, an area ratio Sr (%) of the vulcanized rubber powder in a cross-section of the outermost layer of the tread portion is not less than 5% and not greater than 50%, and a ratio (Sr/G) of the area ratio Sr (%) of the vulcanized rubber powder to the thickness G (mm) at the crown portion of the outermost layer of the tread portion is greater than 0.3.