Tyre Hooping Reinforcement for Low Rolling Resistance
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Solution Overview
Problem
Tires with a single working layer face challenges in rolling resistance due to inadequate elongation modules, either being too dissipative or too rigid, which affects their flattening and energy efficiency.
Innovation Solution
The tire design incorporates a carcass reinforcement with a single working layer and a hooping reinforcement made of three multifilament strands of aromatic polyamide or polyester, wound helically to provide a moderate elongation module and improved circumferential tension management, reducing rolling resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single working layer is used in the crown reinforcement, then the tire structure is simplified and weight is reduced, but the rolling resistance increases due to inadequate elongation module
Solution Approach 1:
The patent uses composite material construction for the hooping reinforcement, combining aromatic polyamide (providing strength and stiffness) with polyester or aliphatic polyamide (providing elasticity and energy absorption). This composite approach allows the single-layer design to achieve both structural simplicity and optimized rolling resistance through material property complementarity
Solution Approach 2:
The patent optimizes the elongation module parameter of the hooping reinforcement to a specific range (200-650 daN/mm at 1.3% extension) to balance the conflicting requirements of structural simplicity and energy efficiency. This parameter control ensures the single working layer provides adequate flexibility without excessive dissipative losses
2Loss of energy
If the elongation module of the working layer is increased to reduce rolling resistance, then energy dissipation is reduced, but the tire flattening capability deteriorates
Solution Approach 1:
The patent precisely controls the elongation module parameter within the range of 200-650 daN/mm at 1.3% extension, avoiding both excessive stiffness (which would prevent flattening) and excessive flexibility (which would increase energy dissipation). This optimized parameter range simultaneously achieves reduced rolling resistance and maintained flattening capability
Solution Approach 2:
The hooping reinforcement with specific elongation properties is positioned radially outside the working layer to provide localized energy management, while the working layer itself maintains optimized stiffness for contact patch formation. This spatial differentiation of mechanical properties resolves the contradiction between energy dissipation and flattening
3Ease of operation
If the elongation module of the working layer is decreased to improve flattening, then contact patch formation is enhanced, but rolling resistance increases due to excessive dissipative losses
Solution Approach 1:
The patent sets the elongation module of the hooping reinforcement to a minimum of 200 daN/mm at 1.3% extension, ensuring it provides sufficient stiffness to limit dissipative losses during rolling. This parameter threshold prevents excessive energy dissipation while maintaining adequate flattening through the coordinated design of the single working layer
4Ease of manufacture
If conventional wire hooping reinforcement is used, then manufacturing is simplified, but the elongation module is either too low (increasing dissipation) or too high (preventing flattening)
Solution Approach 1:
The patent replaces conventional single-material wire construction with a composite multifilar structure combining aromatic polyamide and polyester or aliphatic polyamide. This composite approach maintains manufacturing simplicity through standardized production processes while achieving the optimized elongation module range that reduces rolling resistance
Solution Approach 2:
The multifilar hooping reinforcement structure serves multiple functions simultaneously: it provides the required hoop strength, delivers the optimized elongation module for reduced energy dissipation, and maintains compatibility with conventional manufacturing processes. This multi-functionality resolves the contradiction between ease of manufacture and energy efficiency
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 achieves lower rolling resistance, efficient flattening, and reduced energy dissipation, while simplifying the manufacturing process and enhancing the tire's guiding and drift rigidity.
Implementation Method 1
the freight reinforcement has a 1.3% lengthening module ranging from 200 to 650 dan/mm
Data Source
Figure 1
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AI summary
A tyre comprising a crown reinforcement, having: - a working reinforcement comprising a single working layer, - a hooping reinforcement arranged radially on the outside of the working layer and comprising at least one hooping wire reinforcement element (170) wound circumferentially in a helical manner so as to extend axially from one axial edge to the other axial edge of the hooping reinforcement. The or each hooping wire reinforcement element (170) consists of: - two multi-filament strands (1701, 1702) of aromatic polyamide or aromatic copolyamide and one multi-filament strand (1703) of aliphatic polyamide or polyester, or - three multi-filament strands of polyester, each multi-filament strand (1701, 1702, 1703) being helically wound about a main axis (W) common to the three multi-filament strands (1701, 1702, 1703). The hooping reinforcement has a tangent modulus at 1.3% elongation ranging from 200 to 650 daN/mm.