Ultra-deformation-resistant aviation tire bead cushion structure and preparation method thereof

Abstract

The application discloses an aviation tire bead buffer structure with super-large deformation resistance and a preparation method thereof. The bead buffer structure comprises a bead wire, a bead apex, a bead core wrap and a buffer rubber. The bead apex comprises a top end, a bottom and first and second side walls extending between the top end and the bottom. The bottom of the bead apex is arranged on the top of the bead wire. The bead core wrap surrounds the bead apex and the bead wire into an integral structure. The bead core wrap comprises a top region corresponding to the top end of the bead apex, a first region corresponding to the first side wall and a second region corresponding to the second side wall. The buffer rubber is arranged on the outside of the bead core wrap and covers at least part of the top region, the first region and the second region. According to the characteristics and performance requirements of the aviation tire bead structure, the position, size structure and material performance of the buffer rubber are optimized, and the shear resistance and overall durability of the bead structure and the aviation tire under the condition of super-large deformation are comprehensively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft tires, and in particular to an aircraft tire bead buffer structure resistant to ultra-large deformation, a preparation method thereof, and the aircraft tire. Background Art

[0002] The primary function of an aircraft tire is to support the aircraft, withstand the loads of parking, taxiing, takeoff, landing, and landing, and absorb the impact energy between the aircraft and the runway. During a hard landing or grounding operation, the tire withstands enormous impact loads that can reach over 10 times that of a conventional tire, and the compressive stress and strain energy density on both sides of the bead ring can reach over 8 times that of normal conditions. During this period, the aircraft tire undergoes significant deformation. The combination of this extremely high deformation amplitude and the deformation frequency generated by high speeds causes significant heat generation in areas of concentrated stress and strain within a very short period of time, leading to a rapid degradation of material properties, interfacial delamination, and tire explosion. Therefore, under extreme and special circumstances, aircraft tires must be able to withstand significant deformation to enhance reliability and durability.

[0003] In the prior art of tire structures, a buffer rubber layer has been used as an important improvement measure to improve the bonding strength and stress distribution of the bead area. For example, invention CN110329010B discloses a tire with a apex rubber buffer sheet. The tire structure includes a first cord layer, a second cord layer, a bead, an apex rubber, and a sidewall wear-resistant rubber. The distal end of the apex rubber is bonded with a buffer rubber sheet. The buffer rubber sheet extends upward from the upper end point of the apex rubber sheet along the tire sidewall profile, and its height is limited to between 45% and 60% of the vertical distance from the widest point of the sidewall tire to the bead heel. Although this solution has a certain effect in improving the bonding strength and durability of the tire bead by optimizing the position and size of the buffer rubber sheet, the overall design size and deformation tolerance range of the buffer structure are mainly designed for the normal operating conditions of automobile tires and cannot meet the stringent requirements of the extremely large loads and extremely large deformations on both sides above the wire ring during takeoff and landing of aviation tires.

[0004] Invention CN110978591A focuses on improving the structure and performance of aircraft tires, and specifically discloses a bias-ply aircraft tire that can cope with short-term impact loads and its preparation method. The tire structure includes tire beads, a reverse-wrapped cord layer, a bead core film, a wire ring, a positive cord layer, a bead core film, a hard film, a centerline, and an apex rubber. By optimizing the arrangement of the cord ends, introducing a bead core film to replace the bead core film, and adding a hard film design. Although this invention reduces the number of ends by using the bead core film, partially alleviating the stress concentration between the cords, it does not optimize the shear force distribution between the carcass cord and the bead structure in the buffer structure. The setting of the hard film is more used to enhance wear resistance, but insufficient attention is paid to the interface delamination and material fatigue problems during dynamic large deformation.

[0005] Invention CN110722935A discloses a radial aircraft tire bead structure designed to withstand high-speed fatigue. The structure comprises steel wire rings positioned within each bead, steel wire ring cord strips sequentially wrapped around the wire rings from the inside out, bead core fabric, bead core rubber, carcass plies, and an airtight rubber layer filling the tire cavity. A bead core fabric layer is also positioned beneath the bead to encase the bead. This invention incorporates cushioning films, bead rubber, and bead reinforcement films between the plies to distribute stress within the bead area and prevent delamination and bulging between the plies, at the ply turn-up ends, and between the plies and the sidewall rubber. While this invention interposes the aforementioned cushioning films and other functional films between the plies on the outer side of the apex rubber, while beneficial for improving bead stability and the tire's high-speed fatigue resistance, this significantly offset cushioning approach is unlikely to provide long-term stability against the significant deformation experienced by aircraft tires during takeoff and landing due to the short, intense impact loads.

[0006] Therefore, how to optimize the position, size structure and component material properties of the buffer rubber layer in the design of the aircraft tire bead structure, comprehensively improve the shear resistance and overall durability of the bead structure and its aircraft tire under conditions of ultra-large deformation, and reduce problems such as interface delamination and heat concentration, is an urgent problem to be solved by technical personnel in this field. Summary of the Invention

[0007] In response to the defects existing in the above-mentioned prior art, the present invention provides an aviation tire bead buffer structure that is resistant to ultra-large deformation, a preparation method thereof, and an aviation tire. By improving the size, performance and bonding method of the buffer rubber layer, better stress dispersion and material matching are achieved, effectively improving the shear resistance and durability under ultra-large deformation conditions, and reducing interface delamination and heat concentration problems.

[0008] In a first aspect, the present invention provides an aircraft tire bead buffer structure resistant to ultra-large deformation, the bead buffer structure comprising a wire ring, an apex rubber, a bead core fabric, and a buffer rubber;

[0009] The apex includes a top, a bottom, and a first side wall and a second side wall extending between the top and the bottom, and the bottom of the apex is arranged on the top of the wire ring;

[0010] The bead flipper surrounds the apex and the bead ring into an integral structure, and the bead flipper includes a top area corresponding to the top of the apex, a first area corresponding to the first sidewall, and a second area corresponding to the second sidewall;

[0011] The buffer rubber is arranged on the outer side of the flipper, covering the top area, at least a portion of the first area and at least a portion of the second area.

[0012] During use, especially during takeoff and landing, aircraft tires are subject to far greater impact loads and corresponding deformation than automobile tires. While the sink rate of automobile tires is typically around 10% to 20%, the sink rate of aircraft tires under normal loads is 28% to 35%. A sink rate exceeding 35% is considered unreasonable, and aircraft tires are tolerant to significant deformation. Under exceptional and extreme loads, aircraft tires can experience significant deformation when the sink rate reaches 40% to 80%, which can be extremely destructive to the tire and pose a potential safety risk to the aircraft.

[0013] The present invention forms an integral structure by surrounding the apex rubber and the wire ring with the bead core wrap, and the top area thereof is mainly subjected to the compressive stress from the outside. This is because when the tire contacts the ground, especially under high-impact conditions such as takeoff or landing, the external load first acts on this part, resulting in a large concentration of compressive force. The buffer rubber in this area needs to effectively absorb and disperse these impact loads to avoid damage to the wire ring and the apex rubber. The first and second areas are mainly subjected to shear stress. Since this area connects the bead and the carcass, relative movement will occur between the bead and the carcass during tire deformation, resulting in a large shear force acting on this area. The role of the buffer rubber in this area is to relieve shear stress, reduce the resulting material damage, and enhance shear resistance.

[0014] Therefore, in addition to the structure and composition of the buffer rubber itself, its pasting position and coverage area also need to be carefully considered so that the buffer rubber can still maintain a firm bonding state and buffering capacity after being subjected to impact loads multiple times. According to the overall structure comprising the wire ring and the apex rubber, the present invention covers the top area and the first and second areas with a whole piece of buffer rubber, and adapts the specific size, structure and performance of the buffer rubber. Unlike the existing situation where the buffer rubber is only set on one side of the apex rubber or on both sides of the apex rubber, the tire bead buffer structure of the present invention has good integrity, can achieve better stress dispersion, and improve the shear resistance and durability under super-large deformation conditions. Although the mechanical properties of the rubber used in aircraft tires are generally higher than those of automobile tires, in order to improve the ability of aircraft tires to withstand super-large deformations and improve tire durability and safety, it is also very necessary to set a whole piece of buffer rubber covering a specific area on the periphery of the overall structure formed by the tire bead core cloth, the apex rubber and the wire ring to effectively reduce the destructive force of super-large deformation on the aircraft tire.

[0015] Preferably, it further comprises a wire ring wrapping cloth arranged around the wire ring, and the bottom of the apex rubber is installed on the outer side of the wire ring wrapping cloth corresponding to the top of the wire ring;

[0016] The thickness of the wire ring after wrapping with cloth and coating with glue is 0.8-1.2mm.

[0017] Preferably, the cords in the flipper and / or bead wrap meet at least one of the following conditions:

[0018] 1) Breaking strength ≥210N / piece;

[0019] 2) Elongation at a constant load of 66.6N is 8.0-10.0;

[0020] 3) Elongation at 100N load is 8.6-11.0;

[0021] 4) Adhesion strength ≥150N / cm.

[0022] By limiting the cord's high breaking strength (≥210N / strand), the present invention effectively resists external impact and tensile stress, reducing the risk of breakage. A reasonable range of elongation under constant load (8.0-10.0 at a load of 66.6N, and 8.6-11.0 at a load of 100N) ensures the cord's flexibility and dynamic adaptability during deformation. The limited adhesive strength (≥150N / cm) further enhances the interfacial bonding between the cord and the rubber, preventing interfacial separation or delamination under high-frequency deformation and stress. This design significantly enhances the tensile strength and durability of the bead core wrap and wire bead wrap, improving the stability and reliability of the bead cushion structure under extreme operating conditions and ensuring the long-term performance of aircraft tires under extreme deformation and high impact loads.

[0023] Preferably, the apex meets at least one of the following conditions:

[0024] 1) The Shore A hardness of the apex is 74°-84°, the tensile strength is ≥12MPa, and the elongation at break is ≥180%;

[0025] 2) The width w1 of the bottom of the apex and the width w2 of the top of the wire ring meet the following conditions: w1 / w2 = 0.9-1.1;

[0026] 3) The height of the apex bead h4 and the height of the wire ring h3 meet the following conditions: h4 / h3=1.0-1.4.

[0027] The ratio between the apex base width w1 and the bead ring top width w2 affects the bonding strength and stress distribution properties of the tire bead structure. This ratio determines the contact area and force transfer path between the apex and the bead ring. If the ratio of w1 to w2 is too small, the apex base is too narrow, the contact area is insufficient, and the bonding interface is susceptible to localized high stresses, potentially leading to interface failure or delamination. If the ratio of w1 to w2 is too large, the apex base is too wide, which can lead to an uneven stress transfer path for the bonding material and excessive load dispersion, reducing bonding efficiency. By limiting the ratio of w1 to w2 to between 0.9 and 1.1, the present invention ensures sufficient contact area between the apex and the bead ring, providing good bonding strength while avoiding interface delamination or bonding failure caused by insufficient contact area. Furthermore, this ratio range optimizes the distribution of stress at the contact interface, preventing stress concentration caused by an imbalance in the ratio and ensuring the stability and durability of the tire bead structure under high loads and dynamic deformation.

[0028] The ratio of the apex height h4 to the bead height h3 influences the tire bead's support and stress transfer properties. If h2 is too small relative to h3, the apex height is insufficient to adequately cover the bead, reducing the bond strength between the bead and other bead components and impacting overall structural stability. Simultaneously, the apex's elastic support is weakened, making it unable to effectively distribute the load borne by the bead. If h2 is too large relative to h3, the apex height increases, leading to increased rigidity and a prolonged load transfer path. This can cause localized stress concentration, increase the weight of the tire's overall structure, and impact dynamic performance.

[0029] By controlling the h4 / h3 ratio within the range of 1.0-1.4, this invention ensures proper coverage of the bead ring by the apex, providing sufficient support and bonding strength while optimizing the load transfer path, reducing stress concentration, and improving the durability and stability of the bead structure under high loads. This design achieves a balance between coverage and structural rigidity, ensuring that the bead maintains excellent mechanical properties under both dynamic and static conditions.

[0030] Preferably, the cushioning rubber of the aircraft tire bead cushioning structure satisfies at least one of the following conditions:

[0031] 1) The Shore A hardness of the cushioning rubber is 60°-70°, the 200-300% modulus of tensile stress is ≥11MPa, the tensile strength is ≥22MPa, and the elongation at break is ≥420%;

[0032] 2) The ratio of the thickness of the cushion rubber to the thickness of the bead core fabric is (1-5):(2-3);

[0033] 3) The inner side of the buffer rubber is connected to the tire core wrap, and the vertical height h1 between the highest point of the inner side and the top of the wire ring and the vertical height h2 between the highest point of the inner side and the lower end of the buffer rubber satisfy: 0.4≤h2 / h1<1.0.

[0034] The ratio of the rubber cushion thickness to the core thickness affects the bead structure's cushioning effectiveness and overall mechanical properties. If the rubber cushion is too thin, its cushioning capacity is insufficient, making it difficult to effectively absorb and disperse impact loads. This causes the core to directly bear significant compressive and shear stresses, accelerating material fatigue and the risk of interfacial delamination. If the rubber cushion is too thick, while it can absorb more impact energy, it may result in a relatively insufficient load-bearing capacity for the core, leading to an uneven force transfer path and an increased risk of localized stress concentration. Furthermore, excessively thick rubber cushions can lead to insufficient structural rigidity, impacting the tire's overall stability and dynamic performance.

[0035] By controlling the thickness ratio of the rubber cushion to the bead filler within a range of (1-5):(2-3), this invention achieves a balance between cushioning performance and load-bearing capacity. The moderately thick rubber cushion provides excellent impact energy absorption and stress dispersion, while the bead filler provides sufficient structural support. The synergistic effect of these two ensures the stability, durability, and performance reliability of the bead structure under high impact loads and extreme deformations.

[0036] The present invention limits the ratio of the vertical height h2 between the highest point of the inner side of the rubber buffer and its lower end to the vertical height h1 between the highest point of the inner side and the top of the bead ring to a range greater than or equal to 0.4 and less than 1.0, further limiting the extent to which the rubber buffer covers the first and second areas. To fully utilize the rubber buffer's cushioning effect, the rubber buffer must not only fully cover the outer side of the bead core, but also ensure that its coverage area is not too small. When this ratio is less than 0.4, the distance between the inner side vertex of the rubber buffer and its lowest point is too small, and a large portion of the apex sidewalls and their corresponding bead cores lack the lateral cushioning effect of the rubber buffer. When the bead undergoes significant deformation, the probability of irreversible deformation in the lateral areas lacking cushioning increases, increasing the risk of bead damage. When this ratio is greater than or equal to 1, the rubber buffer begins to overlap with the side of the bead ring and its corresponding bead core, significantly reducing the overall cushioning effect of the bead and increasing the amount of rubber buffer used and the weight of the bead. Therefore, on the basis of giving full play to the cushioning effect of the cushion rubber and reducing the tire bead weight and production cost, the above-mentioned optimal ratio range was determined after a large number of experiments.

[0037] Preferably, the overall structure formed by the loop core wrapping cloth has a center line passing through the top area, and the first area and the second area are symmetrically distributed along the center line;

[0038] The thickness of the buffer glue is 0.5-2.0 mm, and is symmetrically or asymmetrically distributed along the center line.

[0039] Preferably, the thickness of the cushioning rubber gradually decreases from the top area of ​​the flipper toward the first area; and / or

[0040] The thickness of the cushion rubber gradually decreases from the top area of ​​the flipper toward the second area.

[0041] The cushioning rubber can be of uniform thickness, preferably tapering from the centerline toward the ends. This effectively reduces the added weight of the cushioning rubber and allows for a smoother transition at the bonding edge between the cushioning rubber and the bead core wrap, reducing areas of stress concentration and improving the integrity of the bead structure. Furthermore, depending on the specific placement of the bead cushioning structure within the bead and its alignment with the outer rubber sheet, a different thickness gradient can be employed on either side, creating an asymmetric distribution of the cushioning rubber along the centerline. This further facilitates stress dispersion during subsequent significant bead deformation.

[0042] Preferably, the cushion rubber comprises multiple stacked cushion rubber layers, with the hardness and / or modulus of the multiple cushion rubber layers gradually decreasing from the inner side to the outer side of the cushion rubber. This creates a hardness / modulus gradient along the cushion rubber from the inner side to the outer side, further improving the cushion gradient from the bead ring and apex rubber to the carcass cord, thereby enhancing the aircraft tire's ability to withstand extreme deformations.

[0043] Preferably, the buffer glue includes a first portion covering the first area and a second portion covering the second area, the first portion and the second portion forming an offset structure, and the offset structure satisfies at least one of the following conditions:

[0044] 1) The first portion and the second portion have different thicknesses or different thickness gradients;

[0045] 2) The first portion and the second portion have different hardness or different hardness gradients;

[0046] 3) The first portion and the second portion have different moduli or different modulus gradients.

[0047] The offset structure also demonstrates an asymmetric distribution of the rubber cushion along the centerline. The design of varying thicknesses or thickness gradients allows the rubber cushion to fine-tune the stress distribution on the left and right sides of the tire bead structure. For example, under asymmetric loads or special operating conditions (such as eccentric loads or lateral forces), different rubber cushion thicknesses can provide differentiated cushioning capacity to accommodate the varying loads on each side.

[0048] Differentiated cushioning rubber hardness or hardness gradients can adjust the rigidity and flexibility of different areas. For example, a higher hardness cushioning rubber on one side provides stronger support to resist high compressive stress, while a lower hardness cushioning rubber on the other side provides better deformation adaptability to absorb impact. Differentiated modulus or modulus gradients can create a gradient cushioning effect, gradually attenuating stress during transmission, avoiding stress concentration or excessive rigidity caused by a single modulus design.

[0049] By differentiating the thickness, hardness, or modulus of the first and second parts, this invention creates an offset cushioning structure that precisely adapts to stress distribution under varying operating conditions, optimizes the load-bearing capacity of the left and right sides of the tire bead, and enhances the overall deformation resistance and dynamic adaptability of the tire bead structure. This offset structural design enhances tire reliability and durability under high impact loads, extreme deformations, and complex stress conditions, while also improving overall structural performance.

[0050] In a second aspect, the present invention further provides a method for preparing the aircraft tire bead buffer structure, comprising the following steps:

[0051] S1: Set the bottom of the apex on the top of the wire ring;

[0052] S2: Using a bead flipper to surround the apex and the bead ring into an integral structure, the bead flipper comprising a top region corresponding to the top of the apex, a first region corresponding to the first sidewall, and a second region corresponding to the second sidewall;

[0053] S3: placing a buffer rubber on the outside of the bead flipper to cover the top area, at least a portion of the first area, and at least a portion of the second area to obtain the aircraft tire bead buffer structure.

[0054] In a third aspect, the present invention further provides an aircraft tire resistant to ultra-large deformation, comprising the aircraft tire bead buffer structure, or comprising the aircraft tire bead buffer structure obtained by the preparation method.

[0055] Specifically, in an aircraft tire, the number of the bead buffer structures is determined by the number of wire rings, and is generally at least 2. For example, when a single wire ring is used, a total of 2 bead buffer structures are symmetrically arranged on the left and right, and further arrangements are made based on the number of wire rings and needs.

[0056] Through the aforementioned design, the aircraft tire of the present invention can not only stably withstand deformation corresponding to a sink rate of 28% to 35% for a long period of time, but can also release force and buffer when the sink rate exceeds 35%, or even reaches 40% to 80% and causes extremely large deformation, thereby ensuring the safe operation of the aircraft tire.

[0057] The present invention has at least the following beneficial effects:

[0058] (1) The present invention optimizes the size, hardness, modulus and bonding position of the buffer rubber, and combines the performance of the overall structure of the wire ring, apex rubber and bead core cloth to achieve stress dispersion, efficient load transfer and enhanced interface bonding performance of the above-mentioned overall structure, thereby effectively improving the shear resistance and durability of the aircraft tire bead structure under ultra-large deformation conditions, reducing problems such as material fatigue, interface delamination and heat concentration, and significantly improving the reliability and service life of the aircraft tire under extreme working conditions.

[0059] (2) The present invention further implements a gradient design and / or offset structure setting for the buffer rubber on the basis of continuously covering the first area, the top area and the second area of ​​the bead core wrap with a whole piece of buffer rubber. This can provide a buffering effect that can withstand extremely large deformations for the overall structure of the bead core wrap, the apex rubber and the wire ring, as well as the bead and the aircraft tire including the overall structure. This can better adapt to the stress requirements of complex working conditions (such as eccentric load, lateral force or asymmetric impact), and optimize the load-bearing capacity and dynamic adaptability of the left and right sides of the tire.

[0060] (3) The manufacturing process of the present invention is simple. Compared with the existing method of laminating cushion glue on one side or on both sides, it simplifies the laminating process, improves production efficiency and material utilization, and meets the economic and consistency requirements of large-scale production of aircraft tires. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 It is a structural schematic diagram of the tire bead buffer structure of the present invention;

[0062] Figure 2 It is a schematic diagram of the dimensions of the tire bead buffer structure of the present invention;

[0063] Figure 3 The figure is a schematic diagram of the bead structure of an aircraft tire having the bead buffer structure of the present invention.

[0064] Explanation of the accompanying symbols: 1-wire ring, 2-wire ring wrapping cloth, 3-bead core wrapping cloth, 4-apex rubber, 5-buffer rubber, h1-vertical height between the highest point of the inner side surface of the buffer rubber and the top of the wire ring, h2-vertical height between the highest point of the inner side surface of the buffer rubber and the lower end of the buffer rubber, h3-wire ring height, h4-apex rubber height, w1-apex rubber bottom width, w2-wire ring top width. DETAILED DESCRIPTION

[0065] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the specification and specific implementation methods. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0066] The terms used in the embodiments of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The singular forms "a," "an," "the," and "the" used in the embodiments of the present invention and the appended claims are also intended to include plural forms, and unless the context clearly indicates otherwise, "a plurality" generally includes at least two.

[0067] It should also be noted that the terms "include," "comprises," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a product or device comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such product or device. In the absence of further limitations, an element defined by the phrase "comprises a..." does not exclude the presence of other identical elements in the product or device comprising the element.

[0068] The following will be combined with the attached Figure 1-3 The bead buffer structure of an aircraft tire resistant to ultra-large deformation and the aircraft tire resistant to ultra-large deformation provided by the present invention are further explained in detail.

[0069] The present invention provides an aircraft tire resistant to large deformation, including an aircraft tire bead buffer structure resistant to large deformation. The number of bead buffer structures is determined by the number of steel rings, generally at least two. For example, when a single steel ring is used, two bead buffer structures are symmetrically provided on the left and right. Figure 3 An example of three side-by-side bead buffer structures on one side of the bead structure is shown. The specific number of bead buffer structures can be further set according to the number of wire rings and needs.

[0070] like Figure 1 As shown, the aircraft tire bead buffer structure resistant to ultra-large deformation of the present invention specifically includes:

[0071] (1) Traveller 1;

[0072] (2) An apex 4, comprising a top, a bottom, and a first side wall and a second side wall extending between the top and the bottom, wherein the bottom of the apex 4 is disposed on the top of the wire ring 1, wherein:

[0073] 1) The Shore A hardness of apex 4 is 74°-84°, the tensile strength is ≥12MPa, and the elongation at break is ≥180%;

[0074] 2) The bottom width w1 of the apex 4 and the top width w2 of the bead ring 1 satisfy: w1 / w2=0.9-1.1;

[0075] 3) The height of the apex bead h4 and the height of the wire ring h3 meet the following conditions: h4 / h3=1.0-1.4.

[0076] (3) a core wrap 3, which surrounds the apex 4 and the bead ring 1 into an integral structure, including a top region corresponding to the top of the apex 4, a first region corresponding to the first side wall, and a second region corresponding to the second side wall;

[0077] The overall structure formed by the flipper 3 has a center line passing through the top area. Preferably, the first area and the second area are symmetrically distributed along the center line.

[0078] The thickness of the buffer rubber 5 gradually decreases from the top area of ​​the flipper 3 to the first area; and / or the thickness of the buffer rubber 5 gradually decreases from the top area of ​​the flipper 3 to the second area.

[0079] (4) Buffer rubber 5, arranged on the outside of the bead core wrap 3, covering the top area of ​​the bead core wrap 3, at least part of the first area, and at least part of the second area, wherein the first area is covered by the first part of the buffer rubber 5, and the second area is covered by the second part of the buffer rubber 5. The Shore A hardness of the buffer rubber 5 is 60°-70°, the 200-300% tensile stress is ≥11MPa, the tensile strength is ≥22MPa, and the elongation at break is ≥420%. The inner side of the buffer rubber 5 is connected to the bead core wrap 3, and the vertical height h1 between the highest point of the inner side and the top of the wire ring and the vertical height h2 between the highest point of the inner side and the lower end of the buffer rubber satisfy the following: 0.4≤h2 / h1<1.0.

[0080] There are multiple design options for the specific structure of the cushioning rubber 5. The cushioning rubber 5 can be symmetrically or asymmetrically distributed along the center line. The criteria for judging symmetrical and asymmetrical distributions include at least one of thickness, shape, hardness, modulus, etc., that is, if the first and second parts have the same indicators, the distribution is considered symmetrical; otherwise, the distribution is considered asymmetrical. Examples are as follows:

[0081] (1) The buffer glue 5 is symmetrically distributed along the center line:

[0082] (1.1) The overall thickness of the cushion rubber 5 is uniform, and the ratio of the thickness of the cushion rubber 5 to the thickness of the bead core fabric 3 is (1-5):(2-3);

[0083] 1.1.1. The hardness and modulus of the first and second parts are the same;

[0084] 1.1.2. The buffer rubber 5 comprises a plurality of stacked buffer rubber layers 5 , wherein the hardness and / or modulus of the plurality of buffer rubber layers 5 gradually decrease from the inner side to the outer side of the buffer rubber 5 , but the hardness and modulus gradients of the first portion and the second portion are consistent;

[0085] (1.2) The thickness of the cushion rubber 5 is uneven. The thickness of the cushion rubber 5 gradually decreases from the top area of ​​the bead core fabric 3 toward the first area and the second area, respectively. However, the gradient of the thickness decrease of the first part and the second part of the cushion rubber 5 is consistent.

[0086] 1.2.1. The hardness and modulus of the first and second parts are the same;

[0087] 1.2.2. The buffer glue 5 may include multiple stacked buffer glue layers 5. From the inner side to the outer side of the buffer glue 5, the hardness and / or modulus of the multiple buffer glue layers 5 gradually decrease, but the hardness and modulus gradients of the first part and the second part are consistent.

[0088] In order to obtain a buffer rubber 5 that is symmetrical along the center line, a design with uniform thickness, hardness and modulus can be adopted, or a design with gradient distribution of the above indicators but overall symmetry can be adopted. The above are only some design examples for thickness, hardness and modulus parameters. The specific design method and adjustable parameters of the present invention are not limited to the above examples.

[0089] (2) The buffer glue 5 is asymmetrically distributed along the center line, including but not limited to:

[0090] (2.1) The overall thickness of the cushion rubber 5 is uniform, and the ratio of the thickness of the cushion rubber 5 to the thickness of the bead core fabric 3 is (1-5):(2-3);

[0091] The first and second parts of the buffer rubber 5 have different hardness or different hardness gradients; and / or different moduli or different modulus gradients;

[0092] (2.2) The thickness of the cushion rubber 5 is uneven. The thickness of the cushion rubber 5 gradually decreases from the top area of ​​the bead core fabric 3 toward the first area and the second area, respectively. However, the gradient of the thickness decrease of the first part and the second part of the cushion rubber 5 is consistent.

[0093] The first and second parts of the buffer rubber 5 have different hardness or different hardness gradients; and / or different moduli or different modulus gradients;

[0094] (2.3) The first portion and the second portion form an offset structure, and the offset structure satisfies at least one of the following conditions:

[0095] 1) The first portion and the second portion have different thicknesses or different thickness gradients;

[0096] 2) The first portion and the second portion have different hardness or different hardness gradients;

[0097] 3) The first portion and the second portion have different moduli or different modulus gradients.

[0098] In addition to the above-mentioned exemplary single or combined methods, there are more design methods to obtain a buffer rubber 5 that is asymmetric along the center line. The specific design method is designed and adjusted according to the configuration quantity and arrangement of the bead buffer structure in the aircraft tire bead structure.

[0099] (5) The bead ring wrap 2 is arranged around the bead ring 1. The thickness of the bead ring wrap 2 after being coated with glue is 0.8-1.2 mm. The bottom of the apex rubber 4 is installed on the outer side of the bead ring wrap 2 corresponding to the top of the bead ring 1. Preferably, the cords in the bead core wrap 3 and / or the bead ring wrap 2 meet at least one of the following conditions:

[0100] 1) Breaking strength ≥210N / piece;

[0101] 2) Elongation at a constant load of 66.6N is 8.0-10.0;

[0102] 3) Elongation at 100N load is 8.6-11.0;

[0103] 4) Adhesion strength ≥150N / cm.

[0104] A method for preparing the bead buffer structure of the aircraft tire includes a molding preparation step of individual components and an overall molding step, wherein the molding preparation step specifically includes:

[0105] Step 1: A single-layer steel belt is made by extruding a steel wire / tube, and then rolled into a coil by a steel bead ring 1 to form a complete steel bead ring 1;

[0106] Step 2: The cord is cut after calendering, or a single cord is extruded through a steel wire / tube strip process to form a steel wire ring wrapped with a rubber coating having a thickness of 0.8-1.2 mm 2;

[0107] Step 3: The cord is calendered and then cut to prepare a bead core fabric 3 having a thickness of 0.8-1.2 mm after being coated with rubber;

[0108] Step 4: Extrusion to prepare apex plastic 4;

[0109] Step 5: Extruding to prepare the buffer glue 5.

[0110] The overall molding process includes:

[0111] S1: Wrap the bead ring wrap 2 around the outside of the bead ring 1, and set the bottom of the apex rubber 4 on the top of the bead ring 1 and outside the bead ring wrap 2;

[0112] S2: Use the bead core wrap 3 to surround the apex 4, the bead ring 1, and the bead ring wrap 2 into an integral structure to ensure that the components are not loose; the bead core wrap 3 includes a top area corresponding to the top of the apex 4, a first area corresponding to the first side wall, and a second area corresponding to the second side wall; the integral structure surrounded by the bead core wrap has a central axis passing through the top area, and the first and second areas are symmetrically distributed along the central axis;

[0113] S3: Based on the center line, a cushioning rubber 5 is arranged on the outside of the bead flipper 3 to cover the top area, at least part of the first area, and at least part of the second area, thereby obtaining the aircraft tire bead cushioning structure.

[0114] Example 1

[0115] An aircraft tire bead buffer structure resistant to ultra-large deformation, specifically comprising:

[0116] (1) Wire ring;

[0117] (2) An apex, comprising a top, a bottom, and a first side wall and a second side wall extending between the top and the bottom, wherein the bottom of the apex is disposed on the top of the wire ring, wherein:

[0118] 4) The Shore A hardness of the apex is about 80°, the tensile strength is ≥12MPa, and the elongation at break is ≥180%;

[0119] 5) The ratio of the apex bottom width w1 to the wire ring top width w2 is approximately 1.0;

[0120] 6) The ratio of the apex height h4 to the wire ring height h3 is approximately 1.2.

[0121] (3) a core wrap, which surrounds the apex and the wire ring into an integral structure, including a top region corresponding to the top of the apex, a first region corresponding to the first sidewall, and a second region corresponding to the second sidewall;

[0122] The integral structure formed by the flipper has a center line passing through the top region, and the first region and the second region are symmetrically distributed along the center line.

[0123] (4) a buffer rubber, arranged on the outside of the bead core wrap, covering the top area, the first area, and the second area of ​​the bead core wrap, wherein the area covering the first area is the first portion of the buffer rubber, and the area covering the second area is the second portion of the buffer rubber. The buffer rubber has a Shore A hardness of approximately 65°, a 300% modulus of elongation of approximately 13 MPa, a tensile strength of ≥22 MPa, and an elongation at break of ≥420%. The inner side of the buffer rubber is connected to the bead core wrap 3, and the vertical height h1 between the highest point of the inner side and the top of the wire ring and the vertical height h2 between the highest point of the inner side and the lower end of the buffer rubber satisfy the following ratio: h2 / h1 is approximately 0.8.

[0124] The buffer rubber is symmetrically distributed along the center line, and is specifically designed as follows:

[0125] The overall thickness of the cushion rubber is uniform, with the ratio of the cushion rubber thickness to the bead core fabric thickness being 3:2, i.e. the cushion rubber thickness is approximately 1.5mm; and the hardness and modulus of the first and second parts are the same and uniform;

[0126] (5) The bead ring wrap is arranged around the bead ring. The thickness of the bead ring wrap after being coated with glue is about 1.0 mm. The bottom of the apex rubber is installed on the outer side of the bead ring wrap corresponding to the top of the bead ring. The cords in the bead core wrap and the bead ring wrap meet the following conditions:

[0127] 1) Breaking strength ≥210N / piece;

[0128] 2) The elongation at a constant load of 66.6N is approximately 9.2%;

[0129] 3) The elongation at a constant load of 100N is approximately 10.0;

[0130] 4) Adhesion strength ≥150N / cm.

[0131] A method for preparing the bead buffer structure of the aircraft tire includes a molding preparation step of individual components and an overall molding step, wherein the molding preparation step specifically includes:

[0132] Step 1: A single-layer steel wire belt is made by extruding the steel wire / tube, and then rolled into a coil through a steel wire ring to make a complete steel wire ring;

[0133] Step 2: The cord is cut after calendering, or a single cord is made into a steel wire ring with a thickness of about 1.0 after being coated with glue through a steel wire / tube extrusion process;

[0134] Step 3: The cord is calendered and then cut to prepare a bead core cloth with a thickness of about 1.0 mm after being coated with rubber;

[0135] Step 4: Extrusion to prepare apex plastic;

[0136] Step 5: Press out and prepare the buffer glue.

[0137] The overall molding process includes:

[0138] S1: Wrap the bead ring cloth around the outside of the bead ring, and set the bottom of the apex rubber on the top of the bead ring 1 and outside the bead ring cloth;

[0139] S2: Use a core wrap to surround the apex, bead ring, and bead ring wrap into an integral structure to ensure that the components are not loose; the core wrap includes a top area corresponding to the top of the apex, a first area corresponding to the first sidewall, and a second area corresponding to the second sidewall; the integral structure surrounded by the core wrap has a central axis passing through the top area, and the first area and the second area are symmetrically distributed along the central axis;

[0140] S3: Based on the center line, cushion rubber is symmetrically arranged on the outside of the bead core cloth to cover the top area, at least part of the first area, and at least part of the second area, thereby obtaining the aircraft tire bead cushion structure.

[0141] Example 2

[0142] The difference between Example 2 and Example 1 is that the height h4 of the apex rubber and the height h3 of the wire ring are approximately 1.0.

[0143] Example 3

[0144] The difference between Example 3 and Example 1 is that the ratio of the apex height h4 to the wire ring height h3 is approximately 1.4.

[0145] Example 4

[0146] The difference between Example 4 and Example 1 is that the ratio of the thickness of the buffer rubber to the thickness of the bead core cloth is 4:2, the thickness of the bead core cloth after being coated with rubber is about 1.0 mm, and the thickness of the buffer rubber is about 2.0 mm.

[0147] Example 5

[0148] The difference between Example 5 and Example 1 is that the ratio of the thickness of the buffer rubber to the thickness of the bead core cloth is 1:2, the thickness of the bead core cloth after being coated with rubber is about 1.0 mm, and the thickness of the buffer rubber is about 0.5 mm.

[0149] Comparative Example 1

[0150] The difference between Comparative Example 1 and Example 1 is that the buffer rubber is arranged in the first area and the second area outside the bead flipper, but is not an integrated structure and does not cover the top area of ​​the bead flipper.

[0151] Comparative Example 2

[0152] The difference between Comparative Example 2 and Example 1 is that the buffer rubber is arranged in the top area, the first area and the second area on the outside of the tire bead core wrap, but it is not an integrated structure, that is, two pieces of buffer rubber are arranged to cover the first area and the second area respectively, and the extended parts of the two pieces of buffer rubber overlap along the center line to cover the top area.

[0153] The main data of the buffer structure in Examples 1-5 are shown in Table 1:

[0154] Table 1

[0155]

[0156] Example 6

[0157] The cushioning rubber of this embodiment is symmetrically distributed along the center line. However, the difference from Example 1 is that the cushioning rubber of this embodiment is layered from the inner side to the outer side and has a hardness gradient and a modulus gradient. The specific difference is:

[0158] The cushion rubber is symmetrically distributed along the center line, and the overall thickness of the cushion rubber is uniform. From the inner side to the outer side of the cushion rubber, it includes three stacked cushion rubber layers P1, P2, and P3. The ratio of the total thickness of the cushion rubber to the thickness of the bead core cloth is 3:2, that is, the total thickness of the cushion rubber is about 1.5 mm, and the thickness of the three stacked cushion rubber layers is about 0.5 mm.

[0159] From the inner side to the outer side of the buffer rubber, the hardness of the multiple buffer rubber layers gradually decreases, and the Shore A hardness is 70°, 65°, and 60° respectively; the modulus gradually decreases, and the 300% elongation stress is approximately 14MPa, 13MPa, and 11.5MPa, but the hardness and modulus gradients of the first part and the second part are consistent.

[0160] In the preparation process, each buffer rubber layer is first prepared by calendering, and then stacked and installed on the top of the apex rubber in sequence.

[0161] Example 7

[0162] The buffer glue of this embodiment is symmetrically distributed along the center line. The difference from Example 1 is that the buffer glue of this embodiment has a thickness gradient design. The specific difference is:

[0163] The overall thickness of the cushion rubber is uneven, decreasing gradually from the top area of ​​the bead core wrap toward the first and second areas. At the centerline, the cushion rubber is approximately 1.5mm thick, with a 3:2 ratio to the bead core wrap thickness. The thickness decreases to approximately 0.5mm at the ends, with a 1:2 ratio to the bead core wrap thickness. However, the gradient of the thickness decreases in the first and second sections of the cushion rubber, resulting in the same hardness and modulus.

[0164] Example 8

[0165] The cushioning rubber of this embodiment is symmetrically distributed along the center line. The difference from Example 1 is that the cushioning rubber of this embodiment has a thickness gradient and a hardness modulus gradient design. The specific difference is:

[0166] The cushion rubber is symmetrically distributed along the center line, and includes three stacked cushion rubber layers P1, P2, and P3 from the inner side to the outer side. The thickness of the three stacked cushion rubber layers is about 0.5 mm, but the width of the three cushion rubber layers decreases successively, so the overall thickness of the cushion rubber is uneven. The thickness of the cushion rubber decreases step by step from the top area of ​​the bead core cloth to the first area and the second area respectively. The total thickness of the cushion rubber at the center line is about 1.5 mm, and the thickness of the cushion rubber at both ends (only the P1 layer remains) is reduced to about 0.5 mm.

[0167] From the inner side to the outer side of the buffer rubber, the hardness of the three buffer rubber layers gradually decreases, and the Shore A hardness is 70°, 65°, and 60° respectively; the modulus gradually decreases, and the 300% elongation stress is approximately 14MPa, 13MPa, and 11.5MPa, but the hardness and modulus gradients of the first part and the second part are consistent.

[0168] Example 9

[0169] The rubber cushion is asymmetrically distributed along the centerline. The first and second sections form an integral structure with the same hardness and modulus. The total thickness of the rubber cushion at the centerline is approximately 1.5 mm, while the thickness of the second section is 1.5 mm. However, the thickness of the first section gradually decreases from the centerline toward the first section, decreasing to approximately 0.5 mm at the end. In the aircraft tire bead structure, the first section faces the tire cavity, and the second section faces the sidewall.

[0170] The specific data of the buffer rubber setting in Examples 1 and 6-9 are shown in Table 2:

[0171] Table 2

[0172]

[0173] Test methods and results

[0174] Deformation resistance test:

[0175] Our institute prepared 620×180 tires (the tire bead structure can be found in the attached figure) according to the buffer structures and preparation schemes in Examples 1-9 and Comparative Examples 1-2. Figure 3 ).

[0176] The tires were subjected to dynamic simulation tests under corresponding working conditions. The test results showed that the tire samples corresponding to each embodiment were able to complete the dynamic simulation test under the test conditions of bearing the rated load and suddenly increasing the impact load of 164kN within 2s, with a sinking rate of 67.3%. The tires did not suffer any damage during the test. The above test was repeated, and the load limit of the tires with the buffer structure was increased by more than 10 times, among which Examples 1 and 4 increased by more than 12 times, and Examples 6 and 8 increased by more than 13 times. However, the tire samples corresponding to Example 1 were increased only 2 times, and the tire samples corresponding to Example 2 were increased only 4 times, after which they showed varying degrees of deformation or damage and could not withstand further testing. Therefore, the aircraft tires prepared using the buffer structure of the present invention have significantly improved resistance to large impacts and large deformations, and are suitable for promotion and use in aircraft tires.

[0177] Although preferred embodiments of the present invention have been described, further changes and modifications may be made to these embodiments by those skilled in the art once the basic inventive concepts are understood. Therefore, the present invention is intended to include the preferred embodiments as well as all changes and modifications that fall within the scope of the present invention. Obviously, various changes and modifications may be made to the present invention by those skilled in the art without departing from the spirit and scope of the present invention.

Claims

1. An aircraft tire bead buffer structure resistant to ultra-large deformation, characterized in that: The tire bead buffer structure includes a wire ring, an apex rubber, a tire bead core cloth and a buffer rubber; The apex includes a top, a bottom, and a first side wall and a second side wall extending between the top and the bottom, and the bottom of the apex is arranged on the top of the wire ring; The bead flipper surrounds the apex and the bead ring into an integral structure, and the bead flipper includes a top area corresponding to the top of the apex, a first area corresponding to the first sidewall, and a second area corresponding to the second sidewall; The overall structure formed by the loop core wrapping cloth has a center line passing through the top area, and the first area and the second area are symmetrically distributed along the center line; A cushioning rubber is arranged on the outside of the bead flipper, covering the top area, at least a portion of the first area, and at least a portion of the second area, and the cushioning rubber is symmetrically or asymmetrically distributed along the center line; The buffer rubber comprises a plurality of stacked buffer rubber layers, and the hardness and modulus of the plurality of buffer rubber layers gradually decrease from the inner side to the outer side of the buffer rubber; The thickness of the cushion rubber gradually decreases from the top area of ​​the flipper toward the first area; and / or the thickness of the cushion rubber gradually decreases from the top area of ​​the flipper toward the second area; The buffer rubber meets at least one of the following conditions: 1) The Shore A hardness of the cushioning rubber is 60°-70°, the 200-300% modulus of elongation is ≥11MPa, the tensile strength is ≥22MPa, and the elongation at break is ≥420%; 2) The inner side of the cushion rubber is connected to the bead core cloth, and the vertical height h1 between the highest point of the inner side and the top of the wire ring and the vertical height h2 between the highest point of the inner side and the lower end of the cushion rubber satisfy: 0.4≤h2 / h1<1.

0.

2. The aircraft tire bead buffer structure according to claim 1, characterized in that: It also includes a wire ring wrapping cloth arranged around the wire ring, and the bottom of the apex rubber is installed on the outer side of the wire ring wrapping cloth corresponding to the top of the wire ring; The thickness of the wire ring after wrapping with cloth and coating with glue is 0.8-1.2mm.

3. The aircraft tire bead buffer structure according to claim 2, wherein: The cords in the flipper and / or bead wrap meet at least one of the following conditions: 1) Breaking strength ≥210N / piece; 2) Elongation at a constant load of 66.6N is 8.0-10.0; 3) Elongation at 100N load is 8.6-11.0; 4) Adhesion strength ≥150N / cm.

4. The aircraft tire bead buffer structure according to claim 1, wherein: The Shore A hardness of the apex rubber is 74°-84°, the tensile strength is ≥12MPa, and the elongation at break is ≥180%.

5. The aircraft tire bead buffer structure according to claim 1, wherein: The bottom width w1 of the apex and the top width w2 of the wire ring meet the following conditions: w1 / w2=0.9-1.

1.

6. The aircraft tire bead buffer structure according to claim 1, wherein: The height h4 of the apex rubber and the height h3 of the wire ring meet the following conditions: h4 / h3=1.0-1.

4.

7. The aircraft tire bead buffer structure according to any one of claims 1 to 6, characterized in that: The buffer glue includes a first portion covering the first area and a second portion covering the second area, wherein the first portion and the second portion form an offset structure, and the offset structure satisfies at least one of the following conditions: 1) The first portion and the second portion have different thicknesses or different thickness gradients; 2) The first portion and the second portion have different hardness or different hardness gradients; 3) The first part and the second part have different moduli or different modulus gradients.

8. A method for preparing the aircraft tire bead buffer structure according to any one of claims 1 to 7, characterized in that: The steps include: S1: Set the bottom of the apex on the top of the wire ring; S2: Using a bead flipper to surround the apex and the bead ring into an integral structure, the bead flipper comprising a top region corresponding to the top of the apex, a first region corresponding to the first sidewall, and a second region corresponding to the second sidewall; S3: placing a buffer rubber on the outside of the bead flipper to cover the top area, at least a portion of the first area, and at least a portion of the second area to obtain the aircraft tire bead buffer structure.

9. An aircraft tire resistant to ultra-large deformation, characterized in that: The invention comprises the aircraft tire bead buffer structure according to any one of claims 1 to 7, or the aircraft tire bead buffer structure obtained by the preparation method of the aircraft tire bead buffer structure according to claim 8.

Images