Tyre Bead Outer Band Reduces Rolling Resistance
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Solution Overview
Problem
Existing passenger vehicle tires do not adequately reduce rolling resistance, which impacts fuel consumption and is insufficient given current ecological and economic concerns.
Innovation Solution
The tire design incorporates an outer band and bead filler made of a rubber compound with specific elastic and viscous moduli, along with optimized geometry, to significantly reduce rolling resistance while maintaining a firm bead.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional bead structures are used, then the tyre maintains structural integrity, but rolling resistance remains high
Solution Approach 1:
The patent applies parameter changes by modifying the bead filler geometry with specific radial and axial extent ratios, and by changing the rubber compound formulation to achieve optimal rolling resistance while maintaining bead firmness
Solution Approach 2:
The patent uses composite materials by combining specific rubber compounds with optimized bead filler structures, creating a composite bead assembly that reduces rolling resistance while maintaining structural integrity
2Loss of energy
If bead filler extends further radially, then rolling resistance decreases, but tyre mass increases
Solution Approach 1:
The patent optimizes the bead filler radial extent to be between 0.15H and 0.35H (where H is tyre section height), finding the optimal balance between rolling resistance reduction and mass increase through parameter optimization
3Loss of energy
If outer band extends further radially, then rolling resistance decreases, but device complexity increases
Solution Approach 1:
The patent defines the outer band radial extent as between 0.20H and 0.40H from the radially innermost point of the annular reinforcing structure, using parameter optimization to achieve rolling resistance reduction without excessive complexity
Solution Approach 2:
The patent applies local quality by placing the outer band specifically in the radial region between 0.20H and 0.40H, concentrating the rolling resistance reduction effect in the most critical zone without modifying the entire tyre structure
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 achieves a substantial reduction in rolling resistance, improving fuel efficiency and ecological performance without compromising the tire's structural integrity.
Implementation Method 1
an outer band made of a rubber compound having an elastic modulus G' less than or equal to 15 MPa and a viscous modulus G"
Implementation Method 2
a rubber compound having an elastic modulus G' less than or equal to 15 MPa and a viscous modulus G" such that: the elastic and viscous moduli being measured at 23°C
Data Source
Figure 1~2
Figure 3~5
Figure 6~8
AI summary
Tyre comprising two beads (20), two sidewalls (30) joining in a crown, and at least one carcass reinforcement (60) extending from the beads through the sidewalls to the crown, the carcass reinforcement being anchored in the two beads by a turn-up around an annular reinforcing structure (70) in such a way as to form in each bead an incoming portion (61 ) and a wrapped-around portion (62), wherein each bead comprises a bead filler (1 10) and an outer band (120), the latter being placed axially outside of both the carcass reinforcement and the bead filler, wherein the outer band (120) is made of a rubber compound having an elastic modulus G' less than or equal to 15 MPa and a viscous modulus G" such that: G" [MPa] = 0.2G' [MPa] - 0.2 MPa, the elastic and viscous moduli being measured at 23°C.