Pneumatic Tire Sealing with Closed-Cell Foam Barrier
Solution Overview
Problem
The existing pneumatic vehicle tire designs face challenges in achieving a reliable seal after punctures due to the adverse effect of the foam ring on the sealant's flow behavior, leading to delayed or incomplete sealing, especially when foreign bodies penetrate and exit, leaving behind air ducts.
Innovation Solution
A closed-cell foam ring with a radial thickness of 20 mm to 50 mm is placed between the sound-absorbing open-cell foam ring and the sealant, providing an airtight seal and ensuring that at least 90% of penetrating foreign bodies remain inside, while the sealant's flow behavior is supported by adhesive bonding and strategic layer thickness optimization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a sound-absorbing open-cell foam ring is attached directly to the sealant, then noise level in the vehicle is reduced, but the sealing effect is delayed or compromised due to adverse effect on sealant flow behavior
Solution Approach 1:
A closed-cell foam ring is introduced as an intermediary layer between the sound-absorbing open-cell foam ring and the sealant. This intermediate layer prevents the open-cell foam from adversely affecting the sealant's flow behavior while still allowing the sealant to achieve reliable sealing. The closed-cell foam ring serves as a barrier that maintains both the sealing function and the noise reduction function simultaneously.
Solution Approach 2:
The foam structure is segmented into two distinct types: an outer open-cell foam ring for sound absorption and an inner closed-cell foam ring for maintaining sealant flow properties. This segmentation allows each layer to perform its specific function without interfering with the other, resolving the contradiction between noise reduction and sealing reliability.
2Reliability
If the sealant layer thickness is increased to improve sealing, then sealing reliability improves, but the foam ring cannot be properly attached and material efficiency decreases
Solution Approach 1:
The foam structure is divided into two layers with different cell structures. The closed-cell inner layer provides a suitable surface for sealant attachment with optimized thickness, while the open-cell outer layer provides sound absorption. This segmentation allows the sealant to attach properly to the closed-cell foam without needing excessive thickness, while still achieving reliable sealing.
Solution Approach 2:
Different regions of the foam structure have different qualities: the inner closed-cell foam has a density and porosity suitable for sealant attachment, while the outer open-cell foam has a structure optimized for sound absorption. This local differentiation of material properties allows both functions to be optimized simultaneously without compromising either sealing or manufacturability.
3Reliability
If a closed-cell foam ring with large radial thickness is used to ensure airtightness, then puncture sealing improves, but the overall tire weight increases
Solution Approach 1:
The radial thickness of the closed-cell foam ring is optimized to a specific range (20-50 mm) that provides sufficient airtight sealing for punctures while minimizing weight increase. This parameter optimization ensures that the foam ring is thick enough to contain penetrating foreign bodies (at least 90% containment) but not excessively thick to cause unnecessary weight gain.
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 ensures a reliable airtight seal in the event of punctures, maintaining tire integrity and noise absorption performance, with reduced production costs and improved material efficiency.
Implementation Method 1
a closed-cell foam ring with an airtight effect is arranged between the sound-absorbing foam ring and the sealant
Implementation Method 2
The foam ring reduces the air vibrations in the tire and leads to an improvement in the noise level in the vehicle
Implementation Method 3
the foam ring adhering to a previously applied, automatically sealing sealant which, at least immediately after its application, has the tack required for the foam ring to adhere
Data Source
Figure 1
Figure 2~4
AI summary
A pneumatic vehicle tire is provided. The tire includes a tread, an inner surface lying opposite the tread, a self-sealing sealant and a sound-absorbing open-cell foam ring arranged inside the pneumatic vehicle tire. The foam ring is adhesively attached to the inner surface and adheres to the self-sealing sealant which is applied before the sound-absorbing open-cell foam ring is attached to the inner surface. The self-sealing sealant has, at least immediately after being applied, a tackiness required for an adhesive attachment of the sound-absorbing open-cell foam ring. A closed-cell material ring is arranged between the sound-absorbing foam ring and the self-sealing sealant to prevent a diffusion of the sealant into the open-cell foam ring. The closed-cell material ring effects an airtight condition.