Special tire bead assembly for preventing ring burst and design method

Abstract

The invention belongs to the technical field of tire structures, and discloses a special tire bead assembly for preventing ring burst, which comprises a tire body steel wire layer and a steel wire ring arranged along the outer side of the tire body steel wire layer, and an independently formed bin separation layer is fixedly arranged between the tire body steel wire layer and the steel wire ring. The tire bead failure mode is fundamentally changed by taking directional constraint of a broken steel wire and active dissipation of breaking energy as a core design concept and constructing a composite system of a bin-divided isolation structure and a sacrificial buffer layer, and the bin-divided isolation structure is used for isolating the failure mode of the tire bead through the longitudinal isolation ribs which are periodically distributed in a honeycomb shape and the independent closed isolation bins, so that the failure mode of the tire bead is effectively improved. The steel wire ring is divided into a plurality of controllable fracture units, so that the transverse expansion of cracks is effectively blocked; and the sacrificial buffer layer actively absorbs impact energy generated by steel wire breakage by utilizing the deformability of low-hardness flexible rubber, so that the risk of chain breakage is reduced, and the traditional passive defense thought of'reinforcement and breakage resistance 'is thoroughly abandoned.

Description

Technical Field

[0001] This invention belongs to the field of tire structure technology, specifically a special bead assembly and design method for preventing tire punctures. Background Technology

[0002] With changes in market trends and customer needs, all-steel engineering radial tires are developing towards complex working conditions, high speed, and high load capacity. As speed and load capacity continue to increase, the impact force and torsional force that the tire bead bears during cornering are enormous, greatly increasing the risk of bead burst. Ordinary tire bead structure designs and commonly used "reinforcement against fracture" methods can no longer meet the usage requirements of this type of tire.

[0003] The bead of a standard all-steel radial engineering tire mainly consists of a hexagonal steel wire ring formed by multiple steel wires wound together, a steel wire reinforcement layer, tire carcass cord, and a triangular rubber core. While the standard bead structure of an all-steel radial engineering tire is suitable for use under normal working conditions and meets customer requirements, at relatively high speeds and under high loads, the bead area undergoes repeated torsional deformation. This causes friction and heat generation between materials, leading to rubber aging and a decline in physical properties. This makes it prone to early and mid-stage bead wire punctures and bursts, seriously affecting driving safety and increasing transportation costs. Therefore, improvements are needed. Summary of the Invention

[0004] The purpose of this invention is to provide a special tire bead assembly and design method for preventing tire punctures, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a special tire bead assembly for preventing tire punctures, comprising a tire carcass steel wire layer and a steel wire ring disposed along the outer side of the tire carcass steel wire layer, wherein an independently formed compartmentalized isolation layer is fixedly disposed between the tire carcass steel wire layer and the steel wire ring, and the compartmentalized isolation layer is not integrally vulcanized with the tire carcass steel wire layer or the steel wire ring.

[0006] As a preferred embodiment of the present invention, the carcass steel wire layer is made of high-modulus galvanized steel wire cord with a cord density of 33-45 cords / 10cm.

[0007] As a preferred embodiment of the present invention, the compartmentalized isolation layer is entirely covered on the outside of the tire carcass steel wire layer, with a thickness of 1.3-1.8mm (preferably 1.5mm), and the material is a blend of ethylene propylene diene monomer (EPDM) and natural rubber (NR) (mass ratio 6:4-7:3), with a Shore hardness controlled at 80±5 Shore A.

[0008] As a preferred embodiment of the present invention, the wire ring is formed by winding multiple high-carbon steel wires with a diameter of 1.8-2.0 mm in parallel, with a winding spacing of 0.1-0.2 mm.

[0009] As a preferred embodiment of the present invention, the compartmentalized isolation layer is composed of longitudinal isolation ribs and isolation compartments distributed at equal intervals along the circumference of the tire bead, and the longitudinal isolation ribs and isolation compartments together form a honeycomb structure.

[0010] As a preferred embodiment of the present invention, the width of the longitudinal isolation rib is 2.2-2.8 mm, the spacing is 3.5-4.5 mm, and the cross-section is trapezoidal (upper base is 1.5-2 mm, lower base is 2.2-2.8 mm). The height h of the longitudinal isolation rib and the diameter d of the steel wire in the steel wire ring satisfy: 1.1d≤h≤1.3d (preferably 1.1d≤1.3d). The Shore hardness of the rubber of the longitudinal isolation rib is 15-20 A higher than that of the tire sidewall base rubber (Shore A hardness 60-65), and the elongation at break of the rubber of the longitudinal isolation rib is ≥400%.

[0011] As a preferred embodiment of the present invention, each of the isolation chambers is an independent closed space with a width of 5.5-7.5 mm, and the flexible rubber filled in the isolation chamber has a Shore A hardness of 65-70 and an elongation at break of ≥450%.

[0012] As a preferred embodiment of the present invention, the compartment isolation layer also functions as a tire bead airtight layer.

[0013] To achieve the aforementioned other objective, the present invention also provides the following technical solution: a design method for a special bead assembly for preventing tire punctures, which is applicable to the aforementioned special bead assembly for preventing tire punctures, and the specific steps are as follows: Step 1: Design of the carcass steel wire layer The tire carcass base structure is constructed using high-modulus galvanized steel cord, with a cord density of 33-45 cords / 10cm, ensuring that the bead base strength is compatible with existing conventional material systems without requiring production line modifications. Step 2: Preparation and Parameter Control of Compartmentalized Isolation Layers Material selection: EPDM and natural rubber (NR) blend (mass ratio 6:4-7:3) are selected, with Shore A hardness controlled at 80±5, taking into account both structural support and flexible cushioning performance; Structural design: The entire structure covers the outer side of the carcass steel wire layer, with a thickness of 1.3-1.8mm (preferably 1.5mm); longitudinal isolation ribs (width 2.2-2.8mm, spacing 3.5-4.5mm) and isolation compartments (width 5.5-7.5mm) are evenly distributed along the circumference of the bead, forming a honeycomb structure; Key parameters: The longitudinal isolation rib has a trapezoidal cross-section (upper base 1.5-2mm, lower base 2.2-2.8mm), and the height h and the wire diameter d satisfy 1.1d≤h≤1.3d; the isolation chamber is filled with flexible rubber with a Shore A hardness of 65-70 and an elongation at break ≥450%. Step 3: Optimization of the wire ring structure Multiple high-carbon steel wires with a diameter of 1.8-2.0mm are wound in parallel to form the steel wire loops, with the winding spacing controlled at 0.1-0.2mm to maintain the compactness and deformation resistance of the wire loops, while avoiding coating or structural modification of the steel wire body. Step 4: Implementation of component assembly and failure control mechanisms The compartmentalized isolation layer is molded independently and does not form an integral vulcanized connection with the tire carcass steel wire layer or steel wire ring. It acts as a "sacrificial layer" to directionally induce the broken steel wires to bend and wrap around (curvature radius ≤ 5d) to avoid puncturing the tire carcass. When the steel wire breaks, the isolation chamber restricts the lateral displacement of the broken end, and the longitudinal isolation rib dissipates 30%-40% of the kinetic energy through deformation, thus preventing the crack from spreading. Step 5: Integrating airtightness with manufacturing processes The compartment isolation layer also functions as a tire bead airtight layer, with a gas permeability of 3×10⁻⁶ at 25℃ and 1MPa pressure. -9 cm 3 / (cm・s・Pa); During manufacturing, a low-temperature pressing process (40-60℃, 0.3-0.5MPa) is used to pre-fit the compartment isolation layer, followed by steel wire ring winding, tire body reverse wrapping, and vulcanization molding.

[0014] The beneficial effects of this invention are as follows: This invention, based on the core design concept of "directional constraint of broken steel wires + active dissipation of fracture energy," achieves a fundamental transformation in tire bead failure modes by constructing a composite system of "compartmental isolation structure + sacrificial buffer layer." The compartmental isolation structure, through periodically distributed longitudinal isolation ribs and independently enclosed isolation compartments, divides the steel wire bead into multiple controllable fracture units, effectively preventing the lateral propagation of cracks. The sacrificial buffer layer utilizes the deformation capability of low-hardness flexible rubber to actively absorb the impact energy generated by the breakage of the steel wires, reducing the risk of cascading fractures. This completely abandons the traditional passive defense approach of "reinforcing to resist fracture" and shifts to the active failure control logic of "isolation and diffusion control," thereby significantly improving the safety and reliability of tires under complex operating conditions. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the bead structure of the ordinary all-steel engineering radial tire of the present invention; Figure 2 This is a schematic diagram of the layered structure of the bead assembly of the present invention; Figure 3 This is a schematic diagram of the key structure of the compartmentalized isolation layer of the present invention; Figure 4 This is a schematic diagram of the key structural parameters of the compartmentalized isolation layer of the present invention.

[0016] In the diagram: 1. Tire carcass steel wire layer; 2. Compartment isolation layer; 21. Longitudinal isolation rib; 22. Isolation compartment; 3. Steel wire ring. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] like Figures 1 to 4 As shown, this embodiment of the invention provides a special tire bead assembly for preventing tire punctures, including a tire carcass steel wire layer 1 and a steel wire ring 3 arranged along the outer side of the tire carcass steel wire layer. An independently formed compartmentalized isolation layer 2 is fixedly arranged between the tire carcass steel wire layer 1 and the steel wire ring 3. The compartmentalized isolation layer 2 is not integrally vulcanized with the tire carcass steel wire layer 1 or the steel wire ring 3.

[0019] The compartment isolation layer 2, acting as a "sacrificial layer," will directionally induce the broken steel wires to bend and entangle (bending radius ≤ 5d), thereby preventing the broken ends from puncturing the tire body or triggering a chain of fractures, and thus fundamentally controlling the risk of tire burst.

[0020] Among them, the carcass steel wire layer 1 uses high-modulus galvanized steel wire cord with a cord density of 33-45 cords / 10cm.

[0021] This design ensures the strength of the bead base structure while remaining compatible with existing conventional carcass steel wire layer selections, thus eliminating the need to modify the base material system.

[0022] The compartment isolation layer 2 is completely covered on the outside of the carcass steel wire layer 1, with a thickness of 1.3-1.8mm (preferably 1.5mm). The material is a blend of ethylene propylene diene monomer (EPDM) rubber and natural rubber (NR) (mass ratio 6:4-7:3), and the Shore hardness is controlled at 80±5 Shore A.

[0023] A blend of ethylene propylene diene monomer (EPDM) and natural rubber (NR) with a mass ratio of 6:4-7:3 is selected as the compartment isolation layer 2, and the Shore hardness is controlled at 80±5 Shore A. This design has both a certain structural support and can achieve flexible cushioning.

[0024] Among them, the steel wire ring 3 is formed by multiple high carbon steel wires with a diameter of 1.8-2.0mm wound in parallel, with a winding spacing of 0.1-0.2mm.

[0025] By using high-carbon steel wires to be wound in parallel, the compactness and deformation resistance of the wire coil 3 can be maintained, and no coating or structural modification is made to the wire body.

[0026] The compartmentalized isolation layer 2 is composed of longitudinal isolation ribs 21 and isolation compartments 22 that are evenly distributed along the circumference of the tire bead. The longitudinal isolation ribs 21 and isolation compartments 22 together form a honeycomb structure.

[0027] When a steel wire in the steel wire ring 3 breaks due to fatigue or overload, its broken end will be confined within the independent isolation chamber 22 and will not spread to adjacent steel wires. At the same time, the longitudinal isolation rib 21 dissipates 30%-40% of the kinetic energy generated by the steel wire breakage through its own deformation, thus blocking the propagation path of the crack to the surrounding structure.

[0028] The longitudinal isolation ribs 21 have a width of 2.2-2.8 mm, a spacing of 3.5-4.5 mm, and a trapezoidal cross-section (upper base 1.5-2 mm, lower base 2.2-2.8 mm). The height h of the longitudinal isolation ribs 21 and the diameter d of the steel wire in the steel wire ring 3 satisfy: 1.1d≤h≤1.3d (preferably 1.1d≤1.3d). The Shore hardness of the rubber of the longitudinal isolation ribs 21 is 15-20A higher than that of the tire sidewall base rubber (Shore A hardness 60-65), and the elongation at break of the rubber of the longitudinal isolation ribs 21 is ≥400%.

[0029] The longitudinal isolation ribs 21 are set with a width of 2.2-2.8mm and a spacing of 3.5-4.5mm to form a stable periodic honeycomb structure. The matching design of its trapezoidal cross section (upper base 1.5-2mm, lower base 2.2-2.8mm) and height h (1.1d≤h≤1.3d) ensures mechanical obstruction of broken steel wires. At the same time, the rubber's Shore hardness is 15-20A higher than that of the tire sidewall base rubber and its elongation at break is ≥400%, which allows the isolation ribs to maintain structural integrity when the steel wires break, completely blocking lateral displacement.

[0030] Each isolation chamber 22 is an independent and enclosed space with a width of 5.5-7.5 mm. The flexible rubber filled in the isolation chamber 22 has a Shore A hardness of 65-70 and an elongation at break of ≥450%.

[0031] When the steel wire breaks, the flexible rubber generates a buffering effect through high elastic deformation (elongation at break ≥450%), converting the impact kinetic energy generated by the steel wire breakage into the stretching and slipping energy of the rubber molecular chains, effectively reducing energy transfer efficiency.

[0032] Among them, the compartment isolation layer 2 also functions as a tire bead airtight layer.

[0033] Under standard test conditions (25℃ constant temperature, 1MPa pressure), the compartmentalized isolation layer 2 achieved excellent airtight performance, with its gas permeability strictly controlled to ≤3×10⁻⁶. -9 cm 3 Within the range of / (cm・s・Pa), this index indicates that the isolation layer can effectively block gas penetration and ensure the sealing stability of the tire under high pressure conditions.

[0034] This invention also provides a design method for a special bead assembly for preventing tire tread rolls. This design method is applicable to the aforementioned special bead assembly for preventing tire tread rolls, and the specific steps are as follows: Step 1: Design of the carcass steel wire layer The tire carcass base structure is constructed using high-modulus galvanized steel cord, with a cord density of 33-45 cords / 10cm, ensuring that the bead base strength is compatible with existing conventional material systems without requiring production line modifications. Step 2: Preparation and Parameter Control of Compartmentalized Isolation Layers Material selection: EPDM and natural rubber (NR) blend (mass ratio 6:4-7:3) are selected, with Shore A hardness controlled at 80±5, taking into account both structural support and flexible cushioning performance; Structural design: The entire structure covers the outer side of the carcass steel wire layer, with a thickness of 1.3-1.8mm (preferably 1.5mm); longitudinal isolation ribs (width 2.2-2.8mm, spacing 3.5-4.5mm) and isolation compartments (width 5.5-7.5mm) are evenly distributed along the circumference of the bead, forming a honeycomb structure; Key parameters: The longitudinal isolation rib has a trapezoidal cross-section (upper base 1.5-2mm, lower base 2.2-2.8mm), and the height h and the wire diameter d satisfy 1.1d≤h≤1.3d; the isolation chamber is filled with flexible rubber with a Shore A hardness of 65-70 and an elongation at break ≥450%. Step 3: Optimization of the wire ring structure Multiple high-carbon steel wires with a diameter of 1.8-2.0mm are wound in parallel to form the steel wire loops, with the winding spacing controlled at 0.1-0.2mm to maintain the compactness and deformation resistance of the wire loops, while avoiding coating or structural modification of the steel wire body. Step 4: Implementation of component assembly and failure control mechanisms The compartmentalized isolation layer is molded independently and does not form an integral vulcanized connection with the tire carcass steel wire layer or steel wire ring. It acts as a "sacrificial layer" to directionally induce the broken steel wires to bend and wrap around (curvature radius ≤ 5d) to avoid puncturing the tire carcass. When the steel wire breaks, the isolation chamber restricts the lateral displacement of the broken end, and the longitudinal isolation rib dissipates 30%-40% of the kinetic energy through deformation, thus preventing the crack from spreading. Step 5: Integrating airtightness with manufacturing processes The compartment isolation layer also functions as a tire bead airtight layer, with a gas permeability of 3×10⁻⁶ at 25℃ and 1MPa pressure. -9 cm 3 / (cm・s・Pa); During manufacturing, a low-temperature pressing process (40-60℃, 0.3-0.5MPa) is used to pre-fit the compartment isolation layer, followed by steel wire ring winding, tire body reverse wrapping, and vulcanization molding.

[0035] In step one, the selection of high-modulus galvanized steel cord not only ensures the basic strength of the tire bead but also reduces production modification costs and improves the feasibility of technology implementation through compatibility with existing material systems. In step two, the material selection and structural design of the compartmentalized isolation layer create a synergistic effect: the EPDM / NR blend, through precise control of Shore hardness and elongation at break, ensures both the isolation layer's active absorption capacity for steel wire fracture energy and the physical blocking of fracture propagation paths through its honeycomb structure. Furthermore, the trapezoidal cross-section and height parameters of the longitudinal isolation ribs ensure their mechanical constraint effect on the lateral displacement of the steel wire. The high elastic deformation of the flexible rubber inside the isolation compartment further reduces energy transfer efficiency; Step 3, the steel wire ring optimization, through the parallel winding process of high carbon steel wire, maintains structural compactness while avoiding the process complexity brought about by coating treatment, thus improving production efficiency; Step 4, the failure control mechanism, through the design of the "sacrificial layer" and the planning of kinetic energy dissipation paths, realizes the transformation from passive defense to active control, significantly reducing the risk of tire bursts; Step 5, the airtightness integration, not only gives the compartment isolation layer a dual function, but also ensures the interface bonding strength between components through the low-temperature pressing process, providing a guarantee for the long-term stability of the tire under high-pressure conditions.

[0036] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0037] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A special bead assembly for preventing tire blowouts, comprising a carcass steel wire layer (1) and a steel wire ring (3) disposed along the outer side of the carcass steel wire layer, characterized in that: An independently formed compartmentalized isolation layer (2) is fixedly provided between the carcass steel wire layer (1) and the steel wire ring (3). The compartmentalized isolation layer (2) does not form an integral vulcanization connection with the carcass steel wire layer (1) or the steel wire ring (3).

2. The anti-burst tire bead assembly according to claim 1, characterized in that: The carcass steel wire layer (1) is made of high-modulus galvanized steel wire cord with a cord density of 33-45 cords / 10cm.

3. The anti-burst tire bead assembly according to claim 1, characterized in that: The compartment isolation layer (2) is completely covered on the outside of the carcass steel wire layer (1), with a thickness of 1.3-1.8mm (preferably 1.5mm). The material is a blend of ethylene propylene diene monomer (EPDM) and natural rubber (NR) (mass ratio 6:4-7:3), and the Shore hardness is controlled at 80±5 Shore A.

4. The anti-burst tire bead assembly according to claim 1, characterized in that: The wire ring (3) is formed by winding multiple high carbon steel wires with a diameter of 1.8-2.0 mm in parallel, with a winding spacing of 0.1-0.2 mm.

5. A tire bead assembly for preventing tire blowouts according to claim 1, characterized in that: The compartment isolation layer (2) is composed of longitudinal isolation ribs (21) and isolation compartments (22) that are evenly distributed along the circumference of the tire bead. The longitudinal isolation ribs (21) and isolation compartments (22) together form a honeycomb structure.

6. A tire bead assembly for preventing tire blowouts according to claim 5, characterized in that: The longitudinal isolation rib (21) has a width of 2.2-2.8 mm, a spacing of 3.5-4.5 mm, and a trapezoidal cross-section (upper base of 1.5-2 mm, lower base of 2.2-2.8 mm). The height h of the longitudinal isolation rib (21) and the diameter d of the steel wire in the steel wire ring (3) satisfy: 1.1d≤h≤1.3d (preferably 1.1d≤1.3d). The rubber Shore hardness of the longitudinal isolation rib (21) is 15-20A higher than that of the tire sidewall base rubber (Shore hardness 60-65 Shore A), and the elongation at break of the rubber of the longitudinal isolation rib (21) is ≥400%.

7. A tire bead assembly for preventing tire blowouts according to claim 5, characterized in that: Each of the isolation chambers (22) is an independent closed space with a width of 5.5-7.5 mm. The flexible rubber filled in the isolation chamber (22) has a Shore A hardness of 65-70 and an elongation at break of ≥450%.

8. A tire bead assembly for preventing tire blowouts according to claim 1, characterized in that: The compartment isolation layer (2) also functions as a tire bead airtight layer.

9. A design method for a special bead assembly for preventing tire punctures, the design method being applicable to the special bead assembly for preventing tire punctures as described in any one of claims 1-8, characterized in that, The specific steps are as follows: Step 1: Design of the carcass steel wire layer The tire carcass base structure is constructed using high-modulus galvanized steel cord, with a cord density of 33-45 cords / 10cm, ensuring that the bead base strength is compatible with existing conventional material systems without requiring production line modifications. Step 2: Preparation and Parameter Control of Compartmentalized Isolation Layers Material selection: EPDM and natural rubber (NR) blend (mass ratio 6:4-7:3) are selected, with Shore A hardness controlled at 80±5, taking into account both structural support and flexible cushioning performance; Structural design: The entire structure covers the outer side of the carcass steel wire layer, with a thickness of 1.3-1.8mm (preferably 1.5mm); longitudinal isolation ribs (width 2.2-2.8mm, spacing 3.5-4.5mm) and isolation compartments (width 5.5-7.5mm) are evenly distributed along the circumference of the bead, forming a honeycomb structure; Key parameters: The longitudinal isolation rib has a trapezoidal cross-section (upper base 1.5-2mm, lower base 2.2-2.8mm), and the height h and the wire diameter d satisfy 1.1d≤h≤1.3d; the isolation chamber is filled with flexible rubber with a Shore A hardness of 65-70 and an elongation at break ≥450%. Step 3: Optimization of the wire ring structure Multiple high-carbon steel wires with a diameter of 1.8-2.0mm are wound in parallel to form the steel wire loops, with the winding spacing controlled at 0.1-0.2mm to maintain the compactness and deformation resistance of the wire loops, while avoiding coating or structural modification of the steel wire body. Step 4: Implementation of component assembly and failure control mechanisms The compartmentalized isolation layer is formed independently and does not form an integral vulcanized connection with the tire carcass steel wire layer or steel wire ring. It acts as a "sacrificial layer" to directionally induce the broken steel wires to bend and wrap (curvature radius ≤ 5d) to avoid puncturing the tire carcass. When the steel wire breaks, the isolation chamber restricts the lateral displacement of the broken end, and the longitudinal isolation rib dissipates 30%-40% of the kinetic energy through deformation, thus preventing the crack from spreading. Step 5: Integrating airtightness with manufacturing processes The compartment isolation layer also functions as a tire bead airtight layer, with a gas permeability of 3×10⁻⁶ at 25℃ and 1MPa pressure. -9 cm 3 / (cm・s・Pa); During manufacturing, a low-temperature pressing process (40-60℃, 0.3-0.5MPa) is used to pre-fit the compartment isolation layer, followed by steel wire ring winding, tire body reverse wrapping, and vulcanization molding.

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