Pneumatic Tire Band Layer Modulus for Durability and Ride Comfort
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Solution Overview
Problem
Conventional pneumatic tires face challenges in achieving both high-speed durability and ride comfort simultaneously.
Innovation Solution
The pneumatic tire design includes a band layer with band cords arranged in the tire circumferential direction, having a 2% modulus of 4500 to 9000 N/mm², and sidewall and bead portions with specific elastic moduli, incorporating aramid fibers to enhance durability and comfort by controlling tread expansion and flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the band layer uses conventional band cords, then the tire structure is simple and easy to manufacture, but the high-speed durability and ride comfort cannot be achieved simultaneously
Solution Approach 1:
The patent applies parameter changes by specifying a precise modulus range (4500-9000 N/mm²) for the band cord to simultaneously achieve high-speed durability and ride comfort. This quantitative parameter control transforms the band layer's mechanical properties to resolve the contradiction between reliability and performance balance.
Solution Approach 2:
The patent employs composite materials by combining the band layer with specific modulus characteristics with other tire components (carcass layer, sidewall rubber with complex elastic modulus 3.0-4.5 MPa, bead apex rubber with complex elastic modulus 20-80 MPa). This multi-layer composite structure enables simultaneous achievement of high-speed durability and ride comfort through synergistic material properties.
2Reliability
If the band cord modulus is increased to improve high-speed durability, then the tread expansion is reduced, but the ride comfort may be compromised
Solution Approach 1:
The patent resolves this contradiction by optimizing the band cord modulus within a specific range (4500-9000 N/mm²). This parameter optimization ensures that the tread expansion is sufficiently controlled for high-speed durability while maintaining flexibility for ride comfort, avoiding the trade-off that would result from using excessively high or low modulus values.
Solution Approach 2:
The patent applies local quality by differentiating the mechanical properties of various tire layers: the band layer has high modulus (4500-9000 N/mm²) for durability, while the sidewall rubber has lower complex elastic modulus (3.0-4.5 MPa) for comfort. This spatial differentiation of material properties allows each region to perform its specific function optimally.
3Ease of operation
If the band cord modulus is decreased to improve ride comfort, then the tread expansion increases, but the high-speed durability is reduced
Solution Approach 1:
The patent resolves this contradiction by establishing a minimum modulus threshold (4500 N/mm²) for the band cord. This parameter setting ensures that even when optimizing for ride comfort, the tread expansion remains controlled enough to maintain high-speed durability, preventing the deterioration that would occur with lower modulus values.
4Stability of the object's composition
If the sidewall rubber complex elastic modulus is increased to improve steering stability, then the ride comfort is improved, but the flexibility is reduced
Solution Approach 1:
The patent applies parameter changes by specifying an optimal range for the sidewall rubber's complex elastic modulus (3.0-4.5 MPa). This parameter optimization balances steering stability and flexibility, ensuring that the sidewall is stiff enough for stable steering response but flexible enough to absorb road irregularities for comfort.
Solution Approach 2:
The patent differentiates the mechanical properties of the sidewall rubber from other tire components. The sidewall rubber's complex elastic modulus (3.0-4.5 MPa) is specifically optimized for its dual function of providing steering stability while maintaining flexibility, distinguishing it from the band layer's higher modulus requirement for durability.
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 design effectively improves high-speed durability and ride comfort by inhibiting tread expansion while maintaining flexibility, achieving a well-balanced performance in both aspects.
Implementation Method 1
A 2% modulus of the band cord is 4500 to 9000 N/mm²... in which the band layer contains the band cord arranged in the tire circumferential direction... effectively improves high-speed durability and ride comfort by inhibiting tread expansion
Implementation Method 2
each sidewall portion has a sidewall rubber disposed outward of the carcass layer in a tire axial direction, and a complex elastic modulus E*1 of the sidewall rubber is 3.0 to 4.5 MPa
Implementation Method 3
the pair of bead portions have bead apex rubbers each disposed outward of the corresponding bead core in the tire radial direction, and a complex elastic modulus E*2 of each bead apex rubber is 20 to 80 MPa
Data Source
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AI summary
Provided is a pneumatic tire in which achievement of both high-speed durability and ride comfort can be easily realized. A pneumatic tire 1 includes: a tread portion 2; a pair of sidewall portions 3; a pair of bead portions 4 in each of which a bead core 5 is embedded; a carcass layer 6 extending between the pair of bead portions 4 so as to straddle each bead core 5; a belt layer 7 disposed outward of the carcass layer 6 in a tire radial direction; and a band layer 9 disposed outward of the belt layer 7 in the tire radial direction. The band layer 9 includes a band cord arranged in a tire circumferential direction. A 2% modulus of the band cord is 4500 to 9000 N/mm2.