Multi-Layer Tire Tread Density Layout for Vibration Noise
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Solution Overview
Problem
Conventional methods for reducing tire vibration noise during running, such as increasing tread density, can lead to rubber chipping and reduced noise suppression effectiveness as the tire wears, compromising running durability.
Innovation Solution
A tire design featuring a tread part composed of two or more rubber layers, where the inner rubber layer has a higher density than the tread surface layer, utilizing an isoprene-based rubber composition with a specific density ratio and incorporating a low-density member on the inner circumferential surface to enhance vibration cancellation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the density of the tread part is increased to suppress vibration noise, then the vibration noise is suppressed, but the energy when the tire rolls is increased, causing cracks and rubber chipping
Solution Approach 1:
The tread part is divided into multiple rubber layers with different densities. The first rubber layer (tread surface) has lower density to maintain durability, while the second rubber layer (inner layer) has higher density to suppress vibration noise. This segmentation allows each layer to perform its specific function without compromising the other.
Solution Approach 2:
Different regions of the tire structure are assigned different density characteristics. The inner rubber layer near the band layer is made denser to target vibration suppression at the source, while the outer tread surface maintains lower density for durability. This local differentiation optimizes the overall performance.
2Object-affected harmful factors
If the density of the tread part is increased to suppress vibration noise, then the vibration noise is suppressed, but the effect is reduced as the tire is worn away, causing noise to gradually increase
Solution Approach 1:
The tread part is divided into multiple rubber layers with different densities. The first rubber layer (tread surface) has lower density to maintain durability, while the second rubber layer (inner layer) has higher density to suppress vibration noise. This segmentation allows each layer to perform its specific function without compromising the other.
Solution Approach 2:
The higher density second rubber layer is positioned internally to provide ongoing vibration suppression as the tire wears. This internal cushioning layer maintains its noise suppression effectiveness even as the outer tread wears away, providing long-term protection against vibration noise.
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
This design effectively suppresses vibration noise while maintaining running durability by distributing energy absorption across multiple rubber layers and reducing wear, thereby maintaining noise reduction over the tire's lifespan.
Implementation Method 1
making density of a rubber layer constituting a tread surface (Dc) smaller than density of an inner rubber layer (Db) than the rubber layer constituting the tread surface in the tire radial direction... the rubber layer having the maximum density is composed of a rubber composition comprising a rubber component comprising an isoprene-based rubber
Data Source
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AI summary
It is an object of the present invention to provide a tire capable of suppressing a vibration noise of a tire during running while securing running durability. The tire comprises a tread part composed of two or more rubber layers (11, 12) is provided, wherein, of the two or more rubber layers, a density Dc of a rubber layer (11) constituting a tread surface and a density Db of an inner rubber layer (12) other than the rubber layer constituting the tread surface in the tire radial direction, the density Db being the maximum density of all layers, satisfy the following inequality, Db/Dc > 1.00, and wherein the rubber layer (12) having the maximum density is composed of a rubber composition comprising a rubber component comprising an isoprene-based rubber.