Hybrid Carcass Tire Structure for Conformability and Drift Rigidity
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Solution Overview
Problem
Tires for agricultural vehicles face challenges in raw conformability and drift rigidity due to the use of PET and multiple carcass layers, making them difficult to manufacture and inefficient in reducing soil compaction.
Innovation Solution
A tire design featuring a carcass reinforcement comprising hybrid elements with aromatic and aliphatic polyamide strands, wound helically to achieve a specific modulus ratio, enhancing conformability and drift rigidity while maintaining resistance to bursting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If PET and multiple carcass layers are used, then burst resistance is improved, but raw conformability deteriorates and manufacturing difficulty increases
Solution Approach 1:
The patent uses a composite carcass reinforcement element combining aromatic polyamide (high strength, low elongation) and aliphatic polyamide (higher elongation, good conformability) in a hybrid structure. This composite approach allows the tire to achieve both good raw conformability for easy manufacturing and sufficient burst resistance through the high-strength aromatic component.
Solution Approach 2:
The patent changes the material parameters by selecting specific polyamide types with different mechanical properties. The aromatic polyamide provides high tensile strength for burst resistance, while the aliphatic polyamide contributes to elongation and conformability, enabling the tire to be manufactured with fewer layers while maintaining performance.
2Strength
If PET and multiple carcass layers are used, then burst resistance is improved, but raw conformability deteriorates
Solution Approach 1:
The hybrid carcass reinforcement element combines aromatic polyamide fibers (providing strength for burst resistance) with aliphatic polyamide fibers (providing elongation and conformability). This composite structure enables the raw tire to conform properly to the mold during manufacturing while maintaining the strength needed for burst resistance in the finished product.
Solution Approach 2:
The patent applies different material properties within the same carcass layer by using a hybrid of two polyamide types. The aromatic polyamide components provide localized strength where needed for burst resistance, while the aliphatic polyamide components provide localized flexibility and conformability in the green state, allowing the tire to be shaped properly during manufacturing.
3Strength
If PET is used, then structural strength is improved, but drift rigidity deteriorates
Solution Approach 1:
The hybrid carcass reinforcement element combines aromatic polyamide (high modulus, provides drift rigidity) with aliphatic polyamide (good strength, maintains structural integrity). This composite approach allows the tire to achieve both structural strength and improved drift rigidity, with the aromatic polyamide specifically contributing to resistance against drift under weak inflation conditions.
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 tire exhibits improved raw conformation and drift rigidity, maintaining equivalent resistance to bursting pressure compared to existing tires, with a bi-modulus curve that allows for better tire performance under varying deformations.
Implementation Method 1
The carcass reinforcement must allow, thanks to green properties, radial expansion and therefore circumferential elongation of the tire so as not to prevent the radial and circumferential deformations imposed on the tire during its manufacturing process
Implementation Method 2
the ratio of the tangent modulus at the equivalent force developed by the raw ply at 7% elongation to the secant modulus at the equivalent force developed by the raw ply at 1% elongation is greater than or equal to 2.00
Implementation Method 3
the adhered carcass reinforcement element(s) are embedded in a polymer composition to form each raw carcass ply
Implementation Method 4
each carcass reinforcement element comprises: an assembly consisting of two multifilament strands of aromatic polyamide or aromatic copolyamide, and a single multifilament strand of aliphatic polyamide, the strands being wound together in a helix to form a layer
Implementation Method 5
maintaining equivalent resistance to bursting pressure compared to existing tires
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
The invention relates to a tyre (10) for an agricultural vehicle, comprising at least one carcass ply (28) which comprises one or more hybrid carcass reinforcing elements (36). The tyre (10) is produced using a method comprising a step of manufacturing each carcass ply (28) in which the one or more adhered carcass reinforcing elements (36) are immersed in a polymer composition in order to form each green carcass ply (27), the ratio of the modulus tangent to the equivalent force generated by the green ply at 7% elongation to the modulus secant to the equivalent force generated by the green ply at 1% elongation being greater than or equal to 2.00. The density of carcass reinforcing elements (36) in the green carcass ply (27) ranges from 50 to 150 carcass reinforcing elements (36) per decimetre of green carcass ply (27) and each carcass reinforcing element (36) creates an angle greater than or equal to 85° with the circumferential direction Z of the tyre (10).