Tyre Carcass Cables with Low Permeability Coating
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Solution Overview
Problem
Heavy-duty tires face challenges in endurance due to fatigue-fretting-corrosion phenomena, leading to reduced lifespan, especially under severe conditions and underinflated modes, while existing solutions increase manufacturing costs.
Innovation Solution
A tire with a radial carcass reinforcement featuring uncoated cables with a permeability test flow rate less than 20 cm³/min and a reduced rubber thickness between the carcass reinforcement and the tire cavity, utilizing a crosslinkable rubber sheath based on diene elastomers, which enhances impermeability and reduces buckling risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the thickness of the rubber layer between the carcass reinforcement and the tire cavity is increased to reduce permeability and prevent corrosion, then the endurance and reliability of the tire is improved, but the manufacturing cost increases due to higher material usage
Solution Approach 1:
The patent changes the permeability parameter of the cable by applying a coating with specific permeability characteristics (less than 20 cm³/min in the permeability test), rather than changing the rubber layer thickness. This allows maintaining low permeability while using less rubber material.
Solution Approach 2:
The patent uses a coating on the cable that replicates the protective function of a thick rubber layer by providing a barrier against moisture and oxygen, thereby achieving the same corrosion prevention effect with minimal rubber thickness.
2Stability of the object's composition
If the thickness of the rubber layer between the carcass reinforcement and the tire cavity is increased to prevent buckling of the cables, then the structural stability is improved, but the manufacturing cost increases due to higher material usage
Solution Approach 1:
The patent changes the mechanical properties parameter of the cable by applying a coating that enhances its resistance to buckling, allowing the cable to maintain structural stability with reduced rubber layer thickness.
Solution Approach 2:
The patent creates a composite structure by coating the cable with a material that combines the high tensile strength of metal with the protective and stabilizing properties of rubber, achieving both corrosion resistance and buckling prevention in a single integrated component.
3Ease of manufacture
If conventional coated cables are used in the carcass reinforcement, then the manufacturing process is simpler, but the permeability is higher leading to increased corrosion and reduced endurance
Solution Approach 1:
The patent changes the permeability parameter of the cable coating to be less than 20 cm³/min, creating a barrier that prevents corrosion while maintaining the simplicity of the manufacturing process. The coating is applied using conventional extrusion methods.
Solution Approach 2:
The patent uses a composite coating structure consisting of multiple layers with different properties, combining the ease of conventional manufacturing with enhanced corrosion protection. The coating includes a rubber base layer and a protective outer layer.
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 improves endurance and reduces manufacturing costs by minimizing corrosion and buckling risks, maintaining performance under various driving conditions and extending tire lifespan while reducing material usage.
Implementation Method 1
utilizing a crosslinkable rubber sheath based on diene elastomers, which enhances impermeability and reduces buckling risks
Implementation Method 2
uncoated cables presenting in the so-called permeability test a flow rate less than 20 cm³/min
Data Source
Figure 1a
Figure 1b
Figure 2~4
AI summary
The invention relates to a tyre with a radial carcass reinforcement, consisting of at least one layer of metal reinforcing elements, said tyre comprising a crown reinforcement surmounted radially by a tread, said tread being connected to two beads via two sidewalls. According to the invention, the metal reinforcing elements of at least one carcass reinforcing layer are non-hooped cables which in the so-called permeability test exhibit a flowrate of less than 20 cm3/min and the thickness of rubber compound between the inside surface of the tyre cavity and the point of a metal reinforcing element of the carcass reinforcement closest to said inside surface of the cavity is less than 4 mm.