Three-Layer Tread Rubber Structure for Wet and Snow Grip
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Solution Overview
Problem
Tires face challenges in maintaining steering stability on wet roads and grip performance on snow after abrasion, with existing technologies not providing a balanced solution.
Innovation Solution
A tire design featuring three rubber layers with specific complex elastic modulus and loss tangent properties, where the second rubber layer has a lower complex elastic modulus and higher loss tangent than the first and third layers, and the tread has land parts and circumferential grooves designed to enhance deformation and grip.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a two-layer cap/base structure is used with small loss tangent rubber in the base layer, then fuel efficiency is improved, but steering stability on wet road and grip performance on snow after abrasion deteriorates
Solution Approach 1:
The tread is divided into three distinct rubber layers (first, second, and third layers) with different material properties. The second layer specifically has high loss tangent (0.35 or more) to improve wet road steering stability, while the first and third layers have low loss tangent to maintain fuel efficiency. This segmentation allows simultaneous optimization of conflicting performance characteristics.
Solution Approach 2:
Different regions of the tread are assigned different rubber compositions tailored to their specific functions. The second layer uses rubber with high loss tangent and specific complex elastic modulus (7 MPa or more) to enhance grip and steering stability where needed, while other layers use low loss tangent rubber for fuel efficiency. This local differentiation resolves the contradiction between energy efficiency and reliability.
2Use of energy by moving object
If a two-layer cap/base structure is used with small loss tangent rubber in the base layer, then fuel efficiency is improved, but grip performance on snow after abrasion deteriorates
Solution Approach 1:
The tread is divided into three distinct rubber layers (first, second, and third layers) with different material properties. The second layer specifically has high loss tangent (0.35 or more) to improve wet road steering stability, while the first and third layers have low loss tangent to maintain fuel efficiency. This segmentation allows simultaneous optimization of conflicting performance characteristics.
Solution Approach 2:
Different regions of the tread are assigned different rubber compositions tailored to their specific functions. The second layer uses rubber with high loss tangent and specific complex elastic modulus (7 MPa or more) to enhance grip and steering stability where needed, while other layers use low loss tangent rubber for fuel efficiency. This local differentiation resolves the contradiction between energy efficiency and reliability.
3Reliability
If the tread rubber is made soft to improve deformation and grip, then grip performance is improved, but steering stability deteriorates due to lack of groove support
Solution Approach 1:
The tread is divided into three distinct rubber layers (first, second, and third layers) with different material properties. The second layer specifically has high loss tangent (0.35 or more) to improve wet road steering stability, while the first and third layers have low loss tangent to maintain fuel efficiency. This segmentation allows simultaneous optimization of conflicting performance characteristics.
Solution Approach 2:
Different regions of the tread are assigned different rubber compositions tailored to their specific functions. The second layer uses rubber with high loss tangent and specific complex elastic modulus (7 MPa or more) to enhance grip and steering stability where needed, while other layers use low loss tangent rubber for fuel efficiency. This local differentiation resolves the contradiction between energy efficiency and reliability.
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 improved steering stability on wet roads and grip performance on snow after abrasion with a good balance, by allowing easy deformation of the tread surface and maintaining firm groove support through the layered rubber composition.
Implementation Method 1
a complex elastic modulus of the second rubber layer at 30°C is lower than a complex elastic modulus of the first rubber layer at 30°C and a complex elastic modulus of the third rubber layer at 30°C
Implementation Method 2
a tan δ of the second rubber layer at 30°C is higher than a tan δ of the first rubber layer at 30°C and a tan δ of the third rubber layer at 30°C
Data Source
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AI summary
In order to provide a tire having improved steering stability on a wet road and grip performance on snow after abrasion with a good balance there is the provision of a tread comprising three or more rubber layers and a complex elastic modulus E* and a loss tangent tan δ of each of the rubber layers have predetermined relationship, wherein an intermediate rubber layer (7) has a complex elastic modulus at 30° C lower than the cap rubber layer (6) and lower than the base rubber layer (8); other tread rubber layer (8); and the intermediate rubber layer (7) has a loss tangent tan δ at 30° C higher than the cap rubber layer (6) and higher than the base rubber layer (8)