Overlarge-deformation-resistant aircraft tire bead buffer structure and preparation method thereof

Abstract

The invention discloses an aircraft tire bead buffering structure resistant to super-large deformation and a preparation method of the aircraft tire bead buffering structure. The tire bead buffering structure comprises a steel wire ring, apex, tire bead core wrapping cloth and buffering rubber. The apex comprises a top end, a bottom, a first side wall and a second side wall, wherein the first side wall and the second side wall extend between the top end and the bottom. The bead core wrapping cloth surrounds the apex and the steel wire ring to form an integral structure, and the bead core wrapping cloth comprises a top area corresponding to the top end of the apex, a first area corresponding to the first side wall and a second area corresponding to the second side wall; the buffer rubber is arranged on the outer side of the bead core wrapping cloth and covers the top area, at least part of the first area and at least part of the second area. According to the characteristics and performance requirements of the aircraft tire bead structure, the position, the size structure, the material performance and the like of the buffer rubber are optimized, and the anti-shearing capacity and the overall durability of the tire bead structure and the aircraft tire under the condition of oversized deformation are comprehensively improved.

Description

Technical Field

[0001] The 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 an aircraft tire. Background Art

[0002] The main function of aircraft tires is to support aircraft, bear the loads of aircraft parking, taxiing, takeoff, landing, and landing, and absorb the impact energy between the aircraft and the runway. Under heavy landing or ground conditions, the huge impact load borne by the tire can reach more than 10 times that of ordinary tires, and the compressive stress and strain energy density on both sides above the wire ring can reach more than 8 times that of ordinary conditions. During this period, the aircraft tire undergoes extremely large deformation. The extremely high deformation amplitude and the deformation frequency generated by high speed are superimposed on each other, causing the tire to generate a large amount of heat in the stress and strain concentration area in a very short time, resulting in a rapid decline in material properties, interface delamination, and tire explosion. Therefore, in extreme and special circumstances, aircraft tires need to have the ability to withstand extremely large deformations to improve reliability and durability.

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

[0004] Invention CN110978591A focuses on the improvement of the structure and performance of aircraft tires, and specifically discloses a bias aircraft tire for coping with short-term impact loads and its preparation method, wherein the tire structure includes tire beads, reverse-layer cords, bead core films, wire rings, positive cord layers, bead core films, hard films, center lines, and apex rubbers. The arrangement of the cord ends is optimized, bead core films are introduced to replace bead core films, and the design of hard films is increased. Although the invention reduces the number of ends through the bead core films and partially alleviates the stress concentration between the cords, the shear force distribution between the carcass cords and the bead structure is not optimized in the buffer structure. The hard films are set more to enhance wear resistance, but insufficient attention is paid to the interface delamination and material fatigue problems in dynamic large deformation.

[0005] Invention CN110722935A discloses a radial aircraft tire bead structure that is resistant to high-speed fatigue, including steel wire rings arranged in the bead on both sides, steel wire ring cord strips sequentially wrapped on the steel wire rings from the inside to the outside, bead core wrapping cloth, bead core rubber film, carcass cord layer and airtight rubber layer filled in the tire cavity, and a bead wrapping cloth layer is also arranged at the lower part of the bead to wrap the bead. The invention arranges a buffer film, a bead film and a bead reinforcement film between each cord layer to disperse the stress in the bead area and prevent the delamination and bulging between the cord layers, the end of the cord layer, and the cord layer and the sidewall rubber from occurring in the bead area. The invention sandwiches the aforementioned buffer film and other functional films between the cord layers on the outer side of the apex rubber, which is beneficial to improve the stability of the bead and the high-speed fatigue resistance of the tire, but the above-mentioned significantly offset buffering method is difficult to stably meet the long-term ultra-large deformation of the aircraft tire due to the short-term huge impact load during take-off and landing.

[0006] Therefore, how to optimize the position, size structure and 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 interface delamination and heat concentration are issues that need to be urgently resolved by technical personnel in this field. Summary of the invention

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

[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, a apex rubber, a bead core cloth 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 core wrap surrounds the apex rubber and the wire ring into an integral structure, and the bead core wrap includes a top area corresponding to the top of the apex rubber, a first area corresponding to the first side wall, and a second area corresponding to the second side wall;

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

[0012] During use, especially during takeoff and landing, the impact load and corresponding deformation of aircraft tires are much greater than those of automobile tires. The sinking rate of automobile tires is usually around 10% to 20%, while the sinking rate of aircraft tires under normal loads is 28% to 35%. When the sinking rate exceeds 35%, it is an unreasonable sinking rate, and aircraft tires can withstand large deformations. Under special and extreme working conditions, when the sinking rate of aircraft tires reaches 40% to 80%, they will deform significantly, which is extremely destructive to aircraft tires and can easily lead to safety risks for 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 area and the second area 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 the deformation of the tire, resulting in a large shear force acting on this area. The role of the buffer rubber in this area is to relieve the shear stress, reduce the material damage caused thereby, and enhance the 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 after being subjected to impact loads for many times, the buffer rubber can still maintain a firm bonding state and buffering capacity. According to the overall structure including 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. Different from the existing situation that 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 tire rubber, 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 bead core wrap, the apex rubber and the wire ring to effectively reduce the destructive force of super-large deformation on the aircraft tire.

[0015] Preferably, 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;

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

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

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

[0019] 2) The elongation at a fixed load of 66.6N is 8.0-10.0;

[0020] 3) The elongation at a fixed load of 100N is 8.6-11.0;

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

[0022] The invention can effectively resist external impact force and tensile stress and reduce the risk of breakage by limiting the high breaking strength of the cord (≥210N / root); the reasonable fixed load elongation range (66.6N load elongation is 8.0-10.0, 100N load elongation is 8.6-11.0) ensures the flexibility and dynamic adaptability of the cord during deformation; the limitation of bonding strength (≥150N / cm) further improves the interfacial bonding performance between the cord and the rubber, and prevents interface 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 ring wrap, improves the stability and reliability of the bead buffer structure under extreme working conditions, and ensures the long-term performance of the aircraft tire under super large deformation and high impact load.

[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 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;

[0026] 3) The height of the apex rubber h4 and the height of the wire ring h3 satisfy: h4 / h3=1.0-1.4.

[0027] The ratio between the bottom width w1 of the apex and the top width w2 of the wire ring affects the bonding strength and stress distribution performance of the tire bead structure. This ratio determines the contact area and force transmission path between the apex and the wire ring. If the ratio of w1 to w2 is too small, the bottom of the apex is too narrow, the contact area is insufficient, and the bonding interface is easily affected by local high stress, which may lead to interface failure or delamination. If the ratio of w1 to w2 is too large, the bottom of the apex is too wide, which may lead to uneven stress transmission path of the bonding material, and excessive load dispersion, reducing bonding efficiency. The present invention ensures that there is sufficient contact area between the apex and the wire ring by limiting the ratio of w1 to w2 to between 0.9 and 1.1, which can not only provide good bonding strength, but also avoid interface delamination or bonding failure caused by insufficient contact area. At the same time, the above-mentioned ratio range can also optimize the distribution of stress at the contact interface, prevent stress concentration problems caused by imbalanced ratios, and ensure the stability and durability of the tire bead structure under high load and dynamic deformation.

[0028] The ratio of the height of the apex bead h4 to the height of the bead bead h3 affects the support performance and stress transfer effect of the tire bead structure. If h2 is too small relative to h3, the height of the apex bead is insufficient and cannot fully cover the bead bead, resulting in a decrease in the bonding strength between the bead bead and other parts of the tire bead, affecting the stability of the overall structure; at the same time, the elastic support of the apex bead is weakened and the load borne by the bead bead cannot be effectively dispersed. If h2 is too large relative to h3, the height of the apex bead will increase the rigidity, making the load transfer path too long, which may cause local stress concentration and increase the weight of the overall tire structure, affecting the dynamic performance.

[0029] The present invention controls h4 / h3 within the range of 1.0-1.4 to ensure that the apex rubber covers the wire ring appropriately, which can not only provide sufficient support and bonding strength, but also optimize the load transfer path, reduce stress concentration problems, and improve the durability and stability of the tire bead structure under high load conditions. This design achieves a balance between covering performance and structural rigidity, allowing the tire bead to maintain good mechanical properties under dynamic and static conditions.

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

[0031] 1) The Shore A hardness of the buffer rubber is 60°-70°, the 200-300% 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 tire bead core cloth is (1-5):(2-3);

[0033] 3) The inner side of the buffer rubber is connected to the tire bead 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 proportional relationship between the thickness of the cushion rubber and the thickness of the tire core cloth affects the cushioning effect and overall mechanical properties of the tire structure. If the cushion rubber is too thin, the cushioning capacity of the cushion rubber is insufficient, and it is difficult to effectively absorb and disperse the impact load, causing the tire core cloth to directly bear greater compressive stress and shear stress, thereby accelerating material fatigue and the risk of interface delamination. If the cushion rubber is too thick, although the cushion rubber can absorb more impact energy, it may cause the tire core cloth to have a relatively insufficient load-bearing capacity, and the force transfer path becomes uneven, thereby increasing the risk of local stress concentration. In addition, excessively thick cushion rubber may lead to insufficient structural rigidity, affecting the overall stability and dynamic performance of the tire.

[0035] The present invention can achieve a balance between cushioning performance and load-bearing capacity by controlling the thickness ratio of the cushioning rubber to the thickness of the bead core cloth within the range of (1-5): (2-3). The cushioning rubber of moderate thickness provides good impact energy absorption and stress dispersion effects, while the bead core cloth provides sufficient structural support. The synergistic effect of the two ensures the stability, durability and performance reliability of the bead structure under high impact loads and large deformation conditions.

[0036] The present invention limits the ratio of the vertical height h2 of the highest point of the inner side surface of the buffer rubber to the lower end of the buffer rubber to the vertical height h1 of the highest point of the inner side surface to the top of the wire ring to a range greater than or equal to 0.4 and less than 1.0, so as to further limit the range of the buffer rubber covering the first area and the second area. To give full play to the buffer effect of the buffer rubber, the buffer rubber not only needs to cover the outer side of the bead core wrapping cloth in one piece, but also the covering area cannot be too small. When the above ratio is less than 0.4, the distance between the vertex of the inner side surface of the buffer rubber and the lowest end point is too small, and a large number of apex rubber side walls and their corresponding bead core wrapping cloths do not have the lateral buffering effect of the buffer rubber. When the bead undergoes a super large deformation, the probability of irreversible deformation of the lateral area lacking the buffering effect doubles, and the risk of bead damage increases. When the ratio is greater than or equal to 1, the buffer rubber begins to overlap with the side surface of the wire ring and its corresponding bead core wrapping cloth, which has very little effect on the overall buffering effect of the bead, but increases the amount of buffer rubber and the weight of the bead. Therefore, the above-mentioned optimal ratio range was determined after a large number of experiments on the basis of giving full play to the cushioning effect of the cushion rubber, reducing the tire bead weight and production cost.

[0037] Preferably, the overall structure surrounded by the 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 it is symmetrically or asymmetrically distributed along the center line.

[0039] Preferably, the thickness of the cushion rubber gradually decreases from the top area of ​​the bead core cloth toward the first area; and / or

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

[0041] The buffer rubber can be of uniform thickness, preferably with a thickness that gradually decreases from the center line to both ends, which can effectively reduce the weight of the buffer rubber, and can also make the transition of the bonding edge between the buffer rubber and the bead core cloth smoother, reduce the stress concentration area, and improve the integrity of the bead structure. In addition, according to the specific setting position of the bead buffer structure in the bead and the fit with the outer film, different thickness gradients on both sides can be used to form an asymmetric distribution of the buffer rubber along the center line, which is more conducive to the subsequent stress dispersion when the bead is over-deformed.

[0042] Preferably, the buffer rubber comprises a plurality of stacked buffer rubber layers, and the hardness and / or modulus of the plurality of buffer rubber layers gradually decrease from the inner side to the outer side of the buffer rubber. A hardness / modulus gradient is formed in the direction from the inner side to the outer side of the buffer rubber, further improving the buffer gradient from the wire ring and the apex rubber to the carcass cord direction, which is beneficial to improving the ability of the aircraft tire to resist large deformation.

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

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

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

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

[0047] The offset structure is also a manifestation of the asymmetric distribution of the cushion rubber along the centerline. Among them, the design of different thicknesses or different thickness gradients enables the cushion rubber to be finely adjusted according to the stress distribution on the left and right sides of the tire bead structure. For example, under asymmetric loads or special working conditions (such as eccentric loads, lateral forces), cushion rubbers of different thicknesses can provide differentiated cushioning capabilities to adapt to the different loads on each side.

[0048] Differentiated design of buffer rubber hardness or hardness gradient can adjust the rigidity and flexibility of different areas. For example, a higher hardness buffer rubber on one side can provide stronger support to resist high compressive stress; a lower hardness on the other side can provide better deformation adaptability to absorb impact. Differentiated design of modulus or modulus gradient can form a gradient buffer effect, so that stress gradually decays during the transmission process, avoiding stress concentration or excessive rigidity caused by a single modulus design.

[0049] The present invention forms an offset buffer structure through differentiated design of the thickness, hardness or modulus of the first part and the second part, which can accurately adapt to the stress distribution under different working conditions; optimize the load-bearing capacity of the left and right sides of the tire bead; and improve the overall anti-deformation performance and dynamic adaptability of the tire bead structure. The offset structural design enables the tire to show higher reliability and durability under high impact loads, large deformations and complex stress conditions, while improving the overall performance of the structure.

[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 core to surround the apex and the wire ring into an integral structure, wherein the bead core includes a top area corresponding to the top of the apex, a first area corresponding to the first side wall, and a second area corresponding to the second side wall;

[0053] S3: placing a buffer rubber on the outside of the bead core cloth 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 according to the number of wire rings, and is generally at least 2. For example, when a single wire ring is used, 2 bead buffer structures are symmetrically arranged on the left and right, and are further arranged according to the number of wire rings and requirements.

[0056] Through the above-mentioned design, the aircraft tire of the present invention can not only stably tolerate the deformation corresponding to the sinking rate of 28% to 35% for a long time, but also can release force and buffer when the sinking rate exceeds 35% or even reaches 40% to 80% and a large deformation occurs, 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) Based on the fact that the entire piece of buffer rubber continuously covers the first area, the top area and the second area of ​​the tire core wrap, the present invention further performs a gradient design and / or an offset structure setting on the buffer rubber, which can provide a buffering effect that can withstand extremely large deformations for the overall structure of the tire core wrap, the apex rubber and the wire ring, as well as the tire bead and the aircraft tire including the overall structure, 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 the cushion glue on one side or laminating the cushion glue on both sides, the laminating process is simplified, the production efficiency and material utilization rate are improved, and the economic efficiency and consistency requirements of large-scale production of aircraft tires are met. 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 drawings: 1-wire ring, 2-wire ring wrapping cloth, 3-tire 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 combination 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 work are within the scope of protection of the present invention.

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

[0067] It should also be noted that the term "includes", "comprising" or any other variation thereof is intended to cover non-exclusive inclusion, so that a commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprising a ..." do not exclude the existence of other identical elements in the commodity or device including the elements.

[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 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 according to the number of wire rings, generally at least 2. For example, when a single wire ring is used, two bead buffer structures are symmetrically arranged. Figure 3 An example of three side-by-side bead buffer structures on one side of the bead structure is shown, and the specific number of bead buffer structures can be further set according to the number of wire rings and requirements.

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

[0071] (1) Bead ring 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 arranged 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 wire ring 1 satisfy: w1 / w2=0.9-1.1;

[0075] 3) The height of the apex rubber h4 and the height of the wire ring h3 satisfy: h4 / h3=1.0-1.4.

[0076] (3) a core wrap 3, which surrounds the apex 4 and the wire ring 1 into an integral structure, including 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;

[0077] The overall structure surrounded by the bead 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 bead flipper 3 to the first area; and / or the thickness of the buffer rubber 5 gradually decreases from the top area of ​​the bead flipper 3 to the second area.

[0079] (4) Buffer rubber 5, arranged on the outside of the tire core wrap 3, covering the top area of ​​the tire 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 tire 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 layer rubber meet the following conditions: 0.4≤h2 / h1<1.0.

[0080] There are multiple design methods for the specific structure of the buffer glue 5, and the buffer glue 5 is symmetrically distributed or asymmetrically distributed along the center line. The judgment index of the symmetrical distribution and the asymmetrical distribution includes at least one of the indexes such as thickness, shape, hardness, modulus, etc., that is, the first part and the second part are considered to be symmetrically distributed if the various indexes are the same, otherwise they are considered to be asymmetrically distributed. Examples are as follows:

[0081] (1) The buffer rubber 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 tire core wrap 3 is (1-5): (2-3);

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

[0084] 1.1.2, the buffer glue 5 includes a plurality of stacked buffer glue 5 layers, and the hardness and / or modulus of the plurality of buffer glue 5 layers gradually decrease from the inner side surface to the outer side surface of the buffer glue 5, but the hardness and modulus gradients of the first part and the second part are consistent;

[0085] (1.2) The thickness of the buffer rubber 5 is uneven. The thickness of the buffer rubber 5 gradually decreases from the top area of ​​the bead core cloth 3 to the first area and the second area, respectively. However, the thickness of the first part and the second part of the buffer rubber 5 decreases in the same gradient.

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

[0087] 1.2.2. The buffer glue 5 may include a plurality of stacked buffer glue 5 layers, and the hardness and / or modulus of the plurality of buffer glue 5 layers gradually decrease from the inner side to the outer side of the buffer glue 5, 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 overall 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, and 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 buffer rubber 5 is uniform, and the ratio of the thickness of the buffer rubber 5 to the thickness of the tire core cloth 3 is (1-5): (2-3);

[0091] The first part and the second part 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 buffer rubber 5 is uneven. The thickness of the buffer rubber 5 gradually decreases from the top area of ​​the bead core cloth 3 to the first area and the second area, respectively. However, the thickness of the first part and the second part of the buffer rubber 5 decreases in the same gradient.

[0093] The first part and the second part 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 part and the second part form a bias structure, and the bias structure satisfies at least one of the following conditions:

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

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

[0097] 3) The first part and the second part 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 wrap 2 is arranged around the bead 1, and the thickness of the bead 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 wrap 2 corresponding to the top of the bead 1; preferably, the cords in the bead core wrap 3 and / or the bead wrap 2 meet at least one of the following conditions:

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

[0101] 2) The elongation at a fixed load of 66.6N is 8.0-10.0;

[0102] 3) The elongation at a fixed load of 100N 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 a single component 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 belt, and then rolled into a coil by a steel bead ring 1 to form a whole steel bead ring 1;

[0106] Step 2: the cord is cut after calendering, or a single cord is made into a steel wire ring wrapped cloth 2 with a thickness of 0.8-1.2 mm after coating with glue by a steel wire / tube strip extrusion process;

[0107] Step 3: The cord is cut after calendering to prepare a bead core cloth 3 with a thickness of 0.8-1.2 mm after coating with rubber;

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

[0109] Step 5: Press out and prepare the buffer glue 5.

[0110] The overall molding process includes:

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

[0112] S2: The bead core wrap 3 is used to surround the apex rubber 4, the wire ring 1, and the wire ring wrap 2 into an integral structure to ensure that the components are not loose; and the bead core wrap 3 includes a top area corresponding to the top of the apex rubber 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 area and the second area are symmetrically distributed along the central line;

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

[0114] Example 1

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

[0116] (1) Wire traveler;

[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 bottom width w1 of the apex to the top width w2 of the wire ring is about 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 to form an integral structure, including a top area corresponding to the top of the apex, a first area corresponding to the first side wall, and a second area corresponding to the second side wall;

[0122] The integral structure surrounded 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) Buffer rubber, arranged on the outside of the tire core wrap, covering the top area, the first area and the second area of ​​the tire core wrap, wherein the first area is covered by the first part of the buffer rubber, and the second area is covered by the second part of the buffer rubber. The Shore A hardness of the buffer rubber is about 65°, the 300% tensile stress is about 13MPa, the tensile strength is ≥22MPa, and the elongation at break is ≥420%. The inner side of the buffer rubber is connected to the tire 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 layer rubber meet the following conditions: h2 / h1 is about 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 buffer rubber is uniform, and the ratio of the thickness of the buffer rubber to the thickness of the tire bead core cloth is 3:2, that is, the thickness of the buffer rubber is about 1.5 mm; and the hardness and modulus of the first part and the second part are the same and uniform;

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

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

[0128] 2) The elongation at a fixed load of 66.6N is about 9.2;

[0129] 3) The elongation at a fixed load of 100N is about 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 a single component and an overall molding step, wherein the molding preparation step specifically includes:

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

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

[0134] Step 3: The cord is cut after calendering to prepare a bead core cloth with a thickness of about 1.0 mm after coating with rubber;

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

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

[0137] The overall molding process includes:

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

[0139] S2: The apex rubber, the wire ring and the wire ring wrap are surrounded by a bead core cloth to form an integral structure, so as to ensure that the components are not loose; and the bead core cloth comprises a top area corresponding to the top of the apex rubber, 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 cloth has a central axis passing through the top area, and the first area and the second area are symmetrically distributed along the central line;

[0140] S3: Based on the center line, the buffer 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, so as to obtain the aircraft tire bead buffer 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 height h4 of the apex rubber and the height h3 of the wire ring are 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 tire bead core cloth is 4:2, the thickness of the tire 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 tire bead core cloth is 1:2, the thickness of the tire 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 core cloth, but is not an integrated structure and does not cover the top area of ​​the bead core cloth.

[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 buffer glue of this embodiment is symmetrically distributed along the center line, but the difference from Example 1 is that the buffer glue of this embodiment is designed in layers from the inner side to the outer side and has a hardness gradient and a modulus gradient. The specific difference is:

[0158] The buffer rubber is symmetrically distributed along the center line, and the overall thickness of the buffer rubber is uniform. From the inner side of the buffer rubber to the outer side, it includes three stacked buffer rubber layers P1, P2, and P3. The ratio of the total thickness of the buffer rubber to the thickness of the tire bead core cloth is 3:2, that is, the total thickness of the buffer rubber is about 1.5 mm, and the thickness of the three stacked buffer 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 Embodiment 1 is that the buffer glue of this embodiment has a thickness gradient design. The specific difference is:

[0163] The overall thickness of the buffer rubber is uneven, and the thickness of the buffer rubber gradually decreases from the top area of ​​the bead core wrap to the first area and the second area: the thickness of the buffer rubber at the center line is about 1.5mm, and the ratio of the thickness of the bead core wrap is 3:2; the thickness of the buffer rubber at both ends is reduced to about 0.5mm, and the ratio of the thickness of the bead core wrap is 1:2. However, the gradient of the thickness reduction of the first part and the second part of the buffer rubber is consistent, and the hardness and modulus of the first part and the second part are the same.

[0164] Example 8

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

[0166] The buffer rubber is symmetrically distributed along the center line, and includes three stacked buffer rubber layers P1, P2, and P3 from the inner side to the outer side. The thickness of the three stacked buffer rubber layers is about 0.5 mm, but the width of the three buffer rubber layers decreases successively, so the overall thickness of the buffer rubber is uneven. From the top area of ​​the tire bead core cloth to the first area and the second area respectively, the thickness of the buffer rubber decreases step by step. The total thickness of the buffer rubber at the center line is about 1.5 mm, and the thickness of the two ends of the buffer rubber (only the P1 layer is left) 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 cushion rubber is asymmetrically distributed along the center line, the first part and the second part are an integral structure, and the hardness and modulus are the same. The total thickness of the cushion rubber at the center line is about 1.5 mm, and the thickness of the second part is 1.5 mm. However, from the center line to the first area, the thickness of the first part gradually decreases, and the thickness of the end portion is reduced to about 0.5 mm. In the tire bead structure of the aircraft tire, the first area faces the tire cavity, and the second area 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 seen 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 show that the tire samples corresponding to each embodiment can complete the dynamic simulation test under the test conditions of bearing the rated load and suddenly increasing the impact load of 164kN within 2s, and the sinking rate reaches 67.3%. The tires were not damaged during the test. The above test was repeated. The load limit of the tire with the buffer structure was increased by more than 10 times, among which, embodiments 1 and 4 were increased by more than 12 times, and embodiments 6 and 8 were increased by more than 13 times. However, the tire samples corresponding to comparative example 1 were increased only 2 times, and the tire samples corresponding to comparative example 2 were increased only 4 times, after which they showed deformation or damage to varying degrees and could not withstand further testing. Therefore, the aviation 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 aviation tires.

[0177] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they are aware of the basic creative concepts. Therefore, the present invention is intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention. Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention.

Claims

1. An aviation tire bead buffer structure resistant to ultra-large deformation, characterized in that: The tire bead buffer structure comprises a wire ring, a 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 core wrap surrounds the apex rubber and the wire ring into an integral structure, and the bead core wrap includes a top area corresponding to the top of the apex rubber, a first area corresponding to the first side wall, and a second area corresponding to the second side wall; The buffer rubber is arranged on the outer side of the bead core cloth, covering the top area, at least a part of the first area and at least a part of the second area.

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 being wrapped with cloth and coated with glue is 0.8-1.2mm.

3. The aircraft tire bead buffer structure according to claim 1, characterized in that: The apex meets at least one of the following conditions: 1) The Shore A hardness of the apex is 74°-84°, the tensile strength is ≥12MPa, and the elongation at break is ≥180%; 2) 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; 3) The height of the apex rubber h4 and the height of the wire ring h3 satisfy: h4 / h3=1.0-1.

4.

4. The aircraft tire bead buffer structure according to any one of claims 1 to 3, characterized in that: The buffer rubber meets at least one of the following conditions: 1) The Shore A hardness of the buffer rubber is 60°-70°, the 200-300% tensile stress is ≥11MPa, the tensile strength is ≥22MPa, and the elongation at break is ≥420%; 2) The ratio of the thickness of the cushion rubber to the thickness of the tire bead core cloth is (1-5):(2-3); 3) The inner side of the buffer rubber is connected to the tire bead 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.

5. The aircraft tire bead buffer structure according to claim 4, characterized in that: The overall structure surrounded by the 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; The thickness of the buffer glue is 0.5-2.0 mm, and it is symmetrically or asymmetrically distributed along the center line.

6. The aircraft tire bead buffer structure according to claim 5, characterized in that: The thickness of the cushion rubber gradually decreases from the top area of ​​the bead flipper toward the first area; and / or The thickness of the buffer rubber decreases gradually from the top area of ​​the bead flipper toward the second area.

7. The aircraft tire bead buffer structure according to claim 5, characterized in that: The buffer glue comprises a plurality of stacked buffer glue layers, and the hardness and / or modulus of the plurality of buffer glue layers gradually decrease from the inner side surface to the outer side surface of the buffer glue.

8. The aircraft tire bead buffer structure according to any one of claims 5 to 7, characterized in that: The buffer glue includes a first part covering the first area and a second part covering the second area, wherein the first part and the second part form an offset structure, and the offset structure satisfies at least one of the following conditions: 1) The first part and the second part have different thicknesses or different thickness gradients; 2) The first part and the second part have different hardness or different hardness gradients; 3) The first part and the second part have different moduli or different modulus gradients.

9. A method for preparing the aircraft tire bead buffer structure according to any one of claims 1 to 8, characterized in that: The steps include: S1: Set the bottom of the apex on the top of the wire ring; S2: using a bead core to surround the apex and the wire ring into an integral structure, wherein the bead core includes a top area corresponding to the top of the apex, a first area corresponding to the first side wall, and a second area corresponding to the second side wall; S3: placing a buffer rubber on the outside of the bead core cloth 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.

10. 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 8, or the aircraft tire bead buffer structure obtained by the preparation method of the aircraft tire bead buffer structure according to claim 9.

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