Multi-Layer Tire Tread Layout for Fuel Efficiency and Steering Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Tires face a challenge in achieving both improved fuel efficiency and steering stability, as existing methods that reduce heat generation in the base tread often compromise on steering stability due to reduced rubber hardness and tire tread rigidity.
Innovation Solution
A tire design with a tread part composed of two or more layers, where the tread inner layer extends into the sidewall and has a specific ratio of center land parts to total land parts, and a rubber composition with a lower loss tangent than the sidewall, optimizing the area ratios and land part configurations to enhance both fuel efficiency and steering stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If carbon black and silica are used in combination for base tread rubber composition to reduce heat generation, then fuel efficiency is improved, but steering stability is lowered due to reduced rubber hardness and tread rigidity
Solution Approach 1:
The patent applies local quality by creating distinct rubber compositions for different tread regions. The center land portion uses a composition optimized for fuel efficiency (lower tan δ, higher silica content), while the shoulder land portion uses a composition optimized for steering stability (higher tan δ, higher carbon black content). This allows each region to have properties tailored to its functional requirements without compromising overall performance
Solution Approach 2:
The tread is segmented into functionally distinct regions with different rubber compositions. The center land and shoulder land portions are separated by circumferential grooves and have different material properties. This segmentation enables the center portion to minimize rolling resistance while the shoulder portions maintain rigidity for steering response
2Reliability
If the tread is designed with optimized land part area ratios to improve steering stability, then steering stability is improved, but fuel efficiency may be compromised due to increased rubber material and heat generation
Solution Approach 1:
The patent utilizes parameter changes by precisely controlling the area ratio of center land parts to total land parts within 0.35-0.65, and adjusting rubber composition parameters (tan δ, silica content, carbon black content) to achieve optimal balance. These parameter optimizations ensure that steering stability requirements are met while minimizing energy loss through reduced hysteresis in the center land region
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 solution results in a tire with improved overall performance in fuel efficiency and steering stability, maintaining compatibility between these two factors, thereby enhancing the tire's overall performance.
Implementation Method 1
where a loss tangent at 30°C of the rubber composition of the tread inner layer is defined as 30°C tan δ BT and a loss tangent at 30°C of the rubber composition of the sidewall in the sidewall part is defined as 30°C tan δ SW
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
It is an object of the present disclosure to provide a tire having improved overall performance of fuel efficiency and steering stability. Provided is a tire comprising a tread part composed of two or more layers and a sidewall part, wherein the tread part composed of two or more layers comprises at least a tread first layer on the outermost side in a tire radial direction and a tread inner layer inside in the tire radial direction, wherein the end of the tread inner layer extends to the sidewall part, the tread inner layer being arranged inside in a tire width direction with respect to a sidewall in the sidewall part, wherein a grounding surface of the tread first layer has two or more circumferential grooves extending continuously in a tire circumferential direction, land parts partitioned by the circumferential grooves, the land parts including a pair of shoulder land parts partitioned by two circumferential grooves located at both ends in the tire width direction and center land parts located between the pair of shoulder land parts, and width direction grooves or width direction grooves and sipes, wherein, where a total area of the land parts is defined as Sr and a total area of the center land parts is defined as Sce, Sr and See satisfy the following inequality (1), and wherein, where a loss tangent at 30°C of the rubber composition of the tread inner layer is defined as 30°C tan δBT and a loss tangent at 30°C of the rubber composition of the sidewall in the sidewall part is defined as 30°C tan δSW, 30°C tan δBT and 30°C tan δSW satisfy the following inequality (2). 0.35≤Sce/Sr≤0.80,and 30°CtanδBT/30°CtanδSW<1