Pneumatic Tire Sponge Member Recess Corner Radius
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Solution Overview
Problem
Pneumatic tires face challenges in reducing cavity resonance noise and heat dissipation, with existing solutions either inadequately addressing sound absorption or compromising durability and assembly workability.
Innovation Solution
A sponge member with protrusions and recesses is integrated into the tire's inner peripheral surface, featuring enlarged corner R portions, semicircular arc shapes, and hollow portions to enhance sound absorption and heat dissipation, while maintaining flexibility and avoiding interference with the rim during assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If a sponge member is attached to the inner peripheral surface of the tread portion to reduce cavity resonance, then sound absorption is improved, but heat dissipation is compromised and temperature inside the tire rises
Solution Approach 1:
The sponge member is segmented into multiple protrusions and recesses rather than being a continuous solid structure. This segmentation increases the surface area for heat dissipation while maintaining sound absorption capabilities through the distributed porous structure.
Solution Approach 2:
The recesses are designed with curved bottom surfaces and rounded corners instead of sharp angles. This curvature increases the surface area for heat transfer and improves the structural flexibility of the sponge member.
2Temperature
If rectangular radiation grooves are formed in the sponge member to promote heat dissipation, then heat dissipation is improved, but sound absorption capability is not optimized
Solution Approach 1:
Instead of rectangular grooves with sharp corners, the invention uses recesses with curved bottom surfaces and rounded corners. This curvature increases the effective surface area for both heat dissipation and sound wave interaction, improving sound absorption while maintaining heat dissipation benefits.
Solution Approach 2:
The invention optimizes the curvature radius of the corner portions to be larger than 25% of the recess width, creating a specific geometric parameter range that simultaneously enhances heat transfer surface area and sound absorption effectiveness.
3Ease of manufacture
If the recess is formed in a rectangular shape, then manufacturing is simple, but the surface area at the bottom is reduced and sound absorption is limited
Solution Approach 1:
The recess bottom surface is designed with a curved shape instead of a flat rectangular bottom. This curvature naturally increases the surface area without requiring complex multi-step manufacturing processes, as the curved shape can be achieved through standard molding techniques with appropriately designed molds.
Solution Approach 2:
By specifying that the corner curvature radius is larger than 25% of the recess width, the invention defines a parameter range that ensures increased surface area while maintaining manufacturability through conventional molding processes.
4Object-generated harmful factors
If the sponge member is made rigid to improve sound absorption structure, then sound absorption is improved, but flexibility and bending durability are reduced
Solution Approach 1:
The curved bottom surfaces and rounded corners in the recesses eliminate stress concentration points that would occur at sharp angles. This curvature distribution allows the sponge member to flex and deform more easily during tire operation, improving bending durability while maintaining the structural integrity needed for sound absorption.
Solution Approach 2:
The sponge member is designed as a flexible porous structure rather than a rigid solid. The combination of protrusions and recesses with curved surfaces creates a flexible architecture that can adapt to tire deformation while maintaining its sound absorption function.
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 design effectively reduces cavity resonance noise and improves heat dissipation, enhancing sound absorption and durability while maintaining ease of assembly, by increasing the surface area for resonance absorption and heat transfer.
Implementation Method 1
a cavity resonance propagating radially in the tire inner cavity is easily received and absorbed by the protrusions and the recesses of the sponge member
Implementation Method 2
since heat transfer from the tread portion is efficiently dissipated by the recesses having an enlarged area, heat dissipation in the recesses improves
Data Source
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AI summary
A pneumatic tire (10) includes: a tread portion (11); and a sponge member (20) extending in a tire circumferential direction and attached to a tire inner peripheral surface of the tread portion over an entire circumference thereof. The sponge member (20) includes: a base portion (21) attached to the tire inner peripheral surface of the tread portion (11); a plurality of protrusions (22) protruding inward in a tire radial direction from the base portion (21) and extending in a tire width direction, the protrusions (22) being formed at intervals in the tire circumferential direction; and a plurality of recesses (23) formed between the plurality of protrusions (22). Corner R portions (23a) are formed in bottom corners of the recesses (23). A curvature radius (R1) of the corner R portions (23a) is larger than 25% of a width (L2) of the recesses (23) in the tire circumferential direction.