Run-Flat Tire Sidewall Reinforcement for Durability and Fuel Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing run flat tires face challenges in achieving a balance between improved run flat durability and fuel efficiency, particularly when transitioning from conventional tire designs with narrow widths and large diameters, as strain concentration and increased rolling resistance affect sidewall performance.
Innovation Solution
A run flat tire design with a side reinforcing layer featuring a rubber composition that satisfies specific viscoelasticity conditions, including a complex elastic modulus and loss tangent ranges, and tire cross-sectional and outer diameter ratios, to enhance durability and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the outer diameter of the tire is increased while maintaining a narrow width, then fuel efficiency is improved, but the sidewall height becomes low causing strain concentration and reduced run flat durability
Solution Approach 1:
The patent applies local quality by providing a side reinforcing layer specifically in the sidewall part of the tire, rather than uniformly reinforcing the entire tire structure. This localized reinforcement targets the specific area experiencing strain concentration during run flat conditions, allowing the tire to maintain low overall weight and good fuel efficiency while providing enhanced durability where needed most.
Solution Approach 2:
The patent uses composite materials by combining a rubber composition with specific viscoelasticity characteristics (complex elastic modulus of 5.0 to 17.0 MPa at 100°C and loss tangent of 0.020 to 0.100 at 60°C) with the side reinforcing layer. This composite structure provides optimized mechanical properties that balance flexibility for comfort with strength for run flat durability, resolving the contradiction between fuel efficiency and reliability.
2Reliability
If the cross-sectional width of the tire is increased, then run flat durability is improved, but the volume of the side part increases causing increased rolling resistance and deteriorated fuel efficiency
Solution Approach 1:
The patent applies local quality by concentrating the reinforcing structure specifically in the sidewall region where it is most needed for run flat performance, rather than increasing the overall cross-sectional width of the tire. This allows the tire to maintain a narrow profile for low rolling resistance while providing localized reinforcement for enhanced durability.
Solution Approach 2:
The patent changes the viscoelasticity parameters of the rubber composition in the side reinforcing layer to achieve optimal balance between durability and fuel efficiency. By controlling the complex elastic modulus (5.0 to 17.0 MPa at 100°C) and loss tangent (0.020 to 0.100 at 60°C), the material provides sufficient strength for run flat conditions while maintaining flexibility to reduce rolling resistance.
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 design improves run flat durability and fuel efficiency by alleviating sidewall strain and reducing heat generation, maintaining a good balance between these performance metrics.
Implementation Method 1
subjecting viscoelasticity of a side reinforcing layer provided in a sidewall part under a specific condition
Data Source
AI summary
Provided is a run flat tire comprising a side reinforcing layer on a sidewall part, wherein a rubber composition of the side reinforcing layer has a complex elastic modulus at 100° C. (E*100) of 5.0 to 17 MPa and a loss tangent at 60° C. (60° C. tan δ) of 0.020 to 0.100 MPa, and wherein, where a tire cross-sectional width is defined as Wt (mm) and a tire outer diameter is defined as Dt (mm), Wt and Dt satisfy any of the following inequality (1), (2), and (3):Wt<225 and Dt≥59.078×Wt{circumflex over ( )}0.460 (1)225≤Wt<235 and Dt≥59.078×Wt{circumflex over ( )}0.620−967.673 (2)235≤Wt and Dt≥Wt{circumflex over ( )}0.6+750 (3)