Run-flat Tire Sidewall Protrusions for Heat Dissipation
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Solution Overview
Problem
Run-flat tires with protrusions on the sidewall face issues of uneven rigidity, leading to reduced riding comfort and durability due to heat generation and periodic vibrations.
Innovation Solution
The design features protrusions on the sidewall that extend in an arc shape with increasing angles relative to the tire radial direction, positioned to overlap in the circumferential direction, enhancing airflow and heat dissipation while maintaining balanced mass and rigidity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If protrusions are added to the sidewall to increase external surface area and generate airflow for heat dissipation, then run-flat durability is improved, but the sidewall rigidity becomes uneven causing periodic vibrations and reduced riding comfort
Solution Approach 1:
The patent applies local quality by making the protrusions have different characteristics at different locations. Specifically, the protrusions are arranged with varying circumferential spacing - closer spacing in regions where additional rigidity is needed and wider spacing where heat dissipation is prioritized. This localized variation in protrusion distribution allows different regions of the sidewall to have optimized properties, resolving the contradiction between run-flat durability and riding comfort.
2Duration of action of stationary object
If protrusions are made larger or more numerous to enhance heat dissipation, then run-flat continuous driving distance is increased, but the tire mass increases excessively
Solution Approach 1:
The patent applies partial action by providing protrusions at selected locations on the sidewall rather than covering the entire surface. The protrusions are strategically positioned to generate sufficient airflow for heat dissipation during run-flat operation, while their number and size are optimized to achieve the necessary cooling effect without adding excessive mass. This partial coverage approach balances heat dissipation requirements with weight constraints.
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 configuration increases the external surface area, effectively dissipates heat, and ensures even rigidity, thereby enhancing run-flat durability and riding comfort while preventing excessive tire mass increase.
Implementation Method 1
Such protrusions generate airflow around the sidewall while the tire is running. The airflow takes heat from the surface of the sidewall, thereby suppressing an increase in temperature in the side-reinforcing rubber layer.
Data Source
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AI summary
[Solution(s)] A run-flat tire 1 is provided with a side-reinforcing rubber layer 10 with an approximately crescent-shaped cross section. On the external surface 3s of at least either sidewall 3, multiple protrusions 14 raised in a tire axially outward direction are arranged in a tire circumferential direction. In a front view of the sidewall 3, the protrusions 14 each extend to incline relative to a tire radial direction. Protrusions 14, 14 adjacent to each other in a tire circumferential direction are positioned to overlap each other in a tire circumferential direction.