Pneumatic Tire Bonding Stiffness Gradient and Peristaltic Air Maintenance
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Solution Overview
Problem
Tire pressure naturally decreases over time, leading to reduced fuel economy, tire life, and vehicle handling performance, and existing Tire Pressure Monitoring Systems require driver intervention for re-inflation.
Innovation Solution
A pneumatic tire assembly with a rigid structure bonded to the tire using a layered thermoplastic material and a peristaltic pump assembly that reroutes pressurized air through a tube-like cavity, maintaining air pressure by segmentally compressing and expanding the air passageway within the tire footprint.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a rigid structure is bonded to the tire, then structural support and air maintenance capability are improved, but bonding reliability deteriorates due to stiffness mismatch between rigid and flexible components
Solution Approach 1:
The bonding system uses a layered thermoplastic material with varying properties: an inner layer with higher melt flow index for strong adhesion to the rigid structure, and an outer layer with lower melt flow index for compatibility with the flexible tire rubber. This local differentiation of material properties resolves the bonding reliability issue while maintaining structural support.
Solution Approach 2:
The invention employs a composite bonding material consisting of multiple thermoplastic layers with different characteristics. The inner layer (e.g., polyethylene with higher MFI) provides strong bonding to the rigid structure, while the outer layer (e.g., polyisoprene with lower MFI) ensures compatibility with the flexible tire, thereby achieving both structural support and bonding reliability.
2Extent of automation
If a bonded rigid structure is used for air maintenance, then driver intervention is eliminated, but the bonding interface may fail under dynamic tire conditions
Solution Approach 1:
The invention changes the material parameters of the bonding layers, specifically the melt flow index, to accommodate dynamic tire conditions. The inner layer has a higher melt flow index (2-10 times that of the outer layer) to provide flexibility and stress absorption, while the outer layer has a lower melt flow index for stable bonding to the tire rubber, ensuring bonding durability under automated operation.
Solution Approach 2:
The bonding system is designed to be dynamic rather than static. The layered thermoplastic material allows for controlled deformation and stress distribution during tire operation, with the inner layer accommodating movements and the outer layer maintaining bonding integrity, thereby ensuring reliability in automated air maintenance systems.
3Ease of manufacture
If a single-layer bonding material is used, then manufacturing is simpler, but bonding performance is insufficient due to incompatible material properties
Solution Approach 1:
The invention uses a composite bonding material with multiple thermoplastic layers, each having different properties optimized for specific bonding functions. The inner layer bonds to the rigid structure while the outer layer bonds to the flexible tire, achieving superior bonding performance through material compatibility.
Solution Approach 2:
Different regions of the bonding material have different properties: the inner layer has higher melt flow index for rigid structure adhesion, while the outer layer has lower melt flow index for flexible tire adhesion. This local quality differentiation ensures optimal bonding performance at each interface.
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 maintains tire pressure without driver intervention, enhancing fuel efficiency, tire longevity, and vehicle handling by continuously re-inflating the tire through a built-in air maintenance system.
Implementation Method 1
the rigid structure being bonded to the tire by a layered thermoplastic material such that a stiffness gradient is created between the structure and the tire
Implementation Method 2
the sidewall groove deforming segment by segment between a non-deformed state and a deformed, constricted state in response to bending of the bending region of the first sidewall while radially within the rolling tire footprint
Data Source
AI summary
A pneumatic tire assembly includes: a tire having a pneumatic cavity; a rigid structure for facilitating operation of the tire assembly, the rigid structure being bonded to the tire by a layered thermoplastic material such that a stiffness gradient is created between the structure and the tire; first and second sidewalls extending respectively from first and second tire bead regions to a tire tread region, the first sidewall having at least one bending region operatively bending when radially within a rolling tire footprint; and a sidewall groove defined by groove walls positioned within the bending region of the first tire sidewall, the sidewall groove deforming segment by segment between a non-deformed state and a deformed, constricted state in response to bending of the bending region of the first sidewall while radially within the rolling tire footprint.