Rubber shock absorber for aviation inertial navigation system as well as rubber composition and preparation method of rubber shock absorber

Abstract

The invention belongs to the technical field of aviation vibration and noise reduction, and particularly relates to a rubber shock absorber for an aviation inertial navigation system and a rubber composition and a preparation method thereof, and the rubber composition for the shock absorber comprises the following raw materials by weight: 90-110 parts of phenyl silicone rubber, 50-70 parts of a reinforcing filler, 10-15 parts of a structure control agent, 5-10 parts of a functional auxiliary agent, and 0.6-1 part of a vulcanizing agent. The rubber composition for the shock absorber provided by the invention adopts the phenyl silicone rubber as a main body material, and is combined with the functional additive, the reinforcing filler, the structure control agent and the vulcanizing agent, so that the effective damping temperature range of a traditional shock absorber is expanded, the dynamic fatigue resistant life of the rubber material is prolonged, and the rubber composition is suitable for wide-temperature-range and long-life rubber shock absorbers, and has wide application prospects. And the reasonable availability of various properties of the shock absorber under the wide temperature range condition is ensured.

Description

Technical Field

[0001] This invention belongs to the field of aviation vibration reduction and noise reduction technology, and specifically relates to a rubber vibration damper for aviation inertial navigation systems, its rubber composition, and its preparation method. Background Technology

[0002] Inertial navigation systems (INS) are core precision devices in aircraft, and their accuracy is easily affected by external vibrations and shocks. Broadband random vibrations (commonly ranging from 5 Hz to 2000 Hz) and high-magnitude shocks generated during takeoff, turbulence, and maneuvers can induce resonance in the equipment, leading to component fatigue failure, signal drift, or structural damage, severely impacting navigation accuracy and reliability. Traditional rigid mounting cannot isolate high-frequency vibrations, requiring the use of elastic damping elements to dissipate energy. Currently, vibration dampers for aircraft inertial navigation systems mainly use materials such as silicone rubber and natural rubber, but these have significant shortcomings in terms of temperature adaptability, triaxial stiffness design, and long service life. Narrow temperature range: Traditional materials undergo glass transition and lose elasticity below -50℃; above 150℃, thermo-oxidative aging accelerates, leading to hardening and cracking. The applicable temperature range of mainstream damping materials in China is close to -40℃ to +70℃, and the temperature range where the damping factor (tanδ) exceeds 0.2 is less than 40℃, which is difficult to cover the working temperature range of inertial navigation systems (-55℃ to +85℃).

[0003] Three-dimensional stiffness imbalance: Inertial navigation system equipment is subjected to multi-directional vibration loads. Rubber vibration dampers used in inertial navigation systems need to have multi-directional damping capabilities. However, ordinary rubber vibration dampers have stiffness differences of more than 30% in the X, Y, and Z directions due to structural anisotropy, causing coupled vibrations. Although there are three-dimensional equal stiffness designs (such as metal-rubber laminates), the damping of metal-rubber drops sharply at low temperatures, and its fatigue life is insufficient.

[0004] Insufficient lifespan: High-damping rubber can improve the vibration reduction efficiency of rubber vibration dampers (e.g., by adding phenyl silicone oil), but increased cross-linking density sacrifices toughness, making it prone to permanent deformation, creasing in the rubber layer, and accelerated creasing propagation into cracks under continuous vibration loads. Data shows that the lifespan of existing rubber vibration dampers used in aviation inertial navigation systems is generally less than 5 years, requiring frequent replacement.

[0005] To overcome these limitations, the industry has tried various solutions, but all have shortcomings: for example, improving damping performance with additives leads to a decrease in mechanical properties; metal-rubber composite vibration damping design can expand the temperature range, but the vibration damper weight increases by 35%, making it unsuitable for lightweight inertial navigation system platforms; metal-rubber vibration dampers expand the temperature range to -70℃ to 500℃, but the weight increases significantly, making it difficult to achieve triaxial equal stiffness, and the manufacturing cost is high; finite element analysis is used to design the vibration damper structure, but the thermal accumulation effect during fatigue process is not considered, resulting in a life prediction error of more than 50%.

[0006] Therefore, the existing shock absorbers and their rubber materials used in inertial navigation systems still need improvement. Summary of the Invention

[0007] The purpose of this invention is to provide a rubber vibration damper for an aerospace inertial navigation system, its rubber composition, and its preparation method. The rubber composition for the vibration damper provided by this invention uses phenyl silicone rubber as the main material, and combines it with functional additives, reinforcing fillers, structural control agents, and vulcanizing agents. This helps to expand the effective damping temperature range of traditional vibration dampers, improve the dynamic fatigue life of rubber materials, and is suitable for wide-temperature-range, long-life rubber vibration dampers, ensuring the reasonable usability of various performance characteristics of the vibration damper under wide-temperature-range conditions.

[0008] The first aspect of the present invention provides a rubber composition for a shock absorber, comprising the following raw materials in parts by weight: 90-110 parts of phenyl silicone rubber, 50-70 parts of reinforcing filler, 10-15 parts of structure control agent, 5-10 parts of functional additive, and 0.6-1 parts of vulcanizing agent.

[0009] In some embodiments, the molecular weight of the phenyl silicone rubber is 500,000 to 800,000, and the phenyl content of the phenyl silicone rubber is 10% to 20%.

[0010] In some embodiments, the elastic modulus of the phenyl silicone rubber is 8 MPa to 15 MPa.

[0011] In some embodiments, under damping temperature ranges of -55°C to 150°C, the loss factor of the phenyl silicone rubber is ≥0.25.

[0012] In some embodiments, the reinforcing filler comprises fumed silica with a specific surface area of ​​150 m². 2 / g~300 m 2 / g.

[0013] In some embodiments, the structure control agent comprises hydroxyl silicone oil, wherein the hydroxyl content of the hydroxyl silicone oil is 5% to 10%.

[0014] In some embodiments, the viscosity of the hydroxyl silicone oil is 50 mPa·s to 100 mPa·s.

[0015] In some embodiments, the hydroxyl silicone oil is a dihydroxyl-terminated silicone oil.

[0016] In some embodiments, the functional additive includes polyvinyl silicone oil, wherein the vinyl content of the polyvinyl silicone oil is 5% to 10%.

[0017] In some embodiments, the viscosity of the polyvinyl silicone oil is 1000 mPa·s to 5000 mPa·s.

[0018] In some embodiments, the vulcanizing agent comprises 2,4-di-tert-butylperoxide cumene.

[0019] In some embodiments, the rubber composition for the shock absorber further includes 0.5 to 1 part of pigment.

[0020] In some embodiments, the pigment comprises chromium trioxide.

[0021] A second aspect of the present invention provides a rubber vibration damper for an aerospace inertial navigation system, comprising a metal core having a first boss, a metal base having a second boss, and a rubber connector disposed between the metal core and the metal base, wherein the second boss of the metal base and at least the first boss portion of the metal core are embedded inside the rubber connector; wherein the raw material of the rubber connector is the rubber composition for vibration dampers described in the first aspect, and the rubber connector is co-vulcanized with the metal core and the metal base to form the vibration damper; the vibration damper operates in an environment with a vibration level RMS of 19 g to 21 g, and operates for a time of not less than 10 h per axial direction; and / or, the operating temperature of the vibration damper is -55°C to 85°C.

[0022] In some embodiments, the rubber connector has an internal receiving cavity, and a first port and a second port communicating with the receiving cavity are opened on opposite sides of the rubber connector. At least a first boss portion of the metal core is embedded in the receiving cavity through the first port, and a first annular rubber groove is opened in the receiving cavity to be inserted and connected to the first boss.

[0023] In some embodiments, the metal core has a columnar core body, and the first boss is annular and sleeved on the outside of the columnar core body.

[0024] In some embodiments, the metal core has a through threaded hole inside, and the extension direction of the threaded hole is the same as the through direction of the receiving cavity.

[0025] In some embodiments, the first protrusion is disposed at the middle position of the columnar core, the bottom of the columnar core and the first protrusion are embedded in the receiving cavity, and the bottom edge of the columnar core is inclined outward and extends downward to form a third protrusion. A third annular rubber groove is provided in the receiving cavity to be inserted and connected to the third protrusion.

[0026] In some embodiments, the total height of the damper is 15.5 mm.

[0027] In some embodiments, the weight of a single shock absorber does not exceed 18 g.

[0028] In some embodiments, the second boss is a hollow cylinder and is disposed on the side of the metal base near the rubber connector, preferably near the second port side of the receiving cavity; a second annular rubber groove is formed on the side wall of the rubber connector, and the second boss is inserted into the second annular rubber groove.

[0029] In some embodiments, the metal base has a through hole extending through its thickness direction, the second boss is connected to the through hole, and the through hole is connected to the receiving cavity.

[0030] In some embodiments, the height of the second boss is 3 mm to 5 mm.

[0031] In some embodiments, the thickness of the metal base is 2 mm to 3 mm.

[0032] In some embodiments, the metal base is provided with mounting holes, the metal base is connected to the outer casing through the mounting holes, and the metal core is connected to the IMU system; or, the metal base is connected to the IMU system through the mounting holes, and the metal core is connected to the outer casing.

[0033] In some embodiments, two mounting holes are provided, and the two mounting holes are symmetrically arranged on both sides of the second boss, with a distance of 45 mm to 50 mm between the centers of the two mounting holes.

[0034] In some embodiments, the diameter of the mounting hole is 3.5 mm.

[0035] A third aspect of the present invention provides a method for preparing a rubber shock absorber for an aerospace inertial navigation system as described in the second aspect, comprising the following steps: mixing the rubber composition for shock absorbers described in the first aspect, and thinning it into a sheet to obtain a mixed rubber; rolling the mixed rubber into a sheet and cutting it into a rubber blank; providing a metal core and a metal base, coating the metal core and the metal base with an adhesive, and drying them; preheating the mold for forming the shock absorber; placing the metal core, the metal base, and the rubber blank coated with adhesive into the preheated mold for vulcanization molding; and after vulcanization molding, demolding to obtain the shock absorber.

[0036] In some embodiments, the preheating temperature of the mold is 170℃±3℃, the pressure is 10 MPa±2 MPa, and the preheating time is not less than 30 min.

[0037] In some embodiments, the vulcanization molding includes: after closing the mold, performing compression vulcanization, venting 3 to 5 times, then pressurizing to a vulcanization pressure of 10 MPa ± 2 MPa and starting timing, with a vulcanization time of 15 min ± 2 min.

[0038] In some embodiments, the drying temperature of the metal core and the metal base after being coated with adhesive is 105℃±5℃, and the drying time is 10 min±1 min.

[0039] The rubber composition for vibration dampers provided by this invention uses phenyl silicone rubber as the main material, and combines it with functional additives, reinforcing fillers, structural control agents and vulcanizing agents. This helps to expand the effective damping temperature range of traditional vibration dampers, improve the dynamic fatigue life of rubber materials, and is suitable for wide-temperature-range, long-life rubber vibration dampers, ensuring the reasonable usability of various performance characteristics of vibration dampers under wide-temperature-range conditions.

[0040] The rubber vibration damper provided by this invention can reduce the impact of airframe vibration on inertial navigation in high vibration levels (RMS reaches 10 g) during flight. By reducing the stress level of the rubber through the vibration damper structural design, the vibration damper achieves equal stiffness and long service life in the vertical, yaw and lateral directions.

[0041] The rubber vibration damper provided by this invention exhibits minimal change in resonant frequency and a reasonable amplitude amplification factor at the resonant point within a temperature range of -55℃ to 85℃, thus having a relatively small impact on vibration damping performance.

[0042] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0043] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0044] Figure 1 This is a schematic diagram of the structure of a rubber vibration damper for an aviation inertial navigation system in an embodiment of the present invention; Figure 2 for Figure 1 Top view of a rubber vibration damper used in China's aviation inertial navigation system; Figure 3 for Figure 2 Cross-sectional view along the AA direction; Figure 4 This is a flowchart illustrating the manufacturing process of the rubber vibration damper for an aerospace inertial navigation system in an embodiment of the present invention.

[0045] Explanation of reference numerals in the attached figures: 100 - Rubber vibration dampers, or dampers, for aircraft inertial navigation systems; 10-Metal core; 11-First boss; 12-Third boss; 13-Threaded hole; 20 - Metal base; 21 - Second boss; 22 - Mounting hole; 30 - Rubber connector; 31 - First annular rubber groove; 32 - Second annular rubber groove; 33 - Third annular rubber groove. Detailed Implementation

[0046] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.

[0047] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0048] In the description of the embodiments of this invention, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this invention, "multiple" means two or more, unless otherwise explicitly defined.

[0049] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0050] In the description of the embodiments of this invention, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0051] In the description of the embodiments of the present invention, the term "multiple" refers to two or more (including two), similarly, "multiple groups" refers to two or more (including two groups), and "multiple pieces" refers to two or more (including two pieces).

[0052] In the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention according to the specific circumstances.

[0053] Inertial navigation systems (INS) are one of the core technologies in aviation navigation. They calculate an aircraft's position, velocity, and attitude in real time using gyroscopes and speedometers, without relying on external signals. During flight, and due to the diversity of the aircraft's heading and attitude, INS inevitably endures complex and varied vibration loads generated by the aircraft. Therefore, vibration dampers must be installed for INS to reduce the vibration loads on vibration-sensitive components such as gyroscopes and speedometers, ensuring the accuracy, stability, and lifespan of the INS.

[0054] Inertial navigation systems are subjected to multidirectional vibration loads, often characterized by wide frequency bands and randomness. Military aircraft, in particular, experience significant vibration loads during rapid maneuvers and acceleration / deceleration. Therefore, the ideal state for vibration dampers in inertial navigation systems is isotropic stiffness, fatigue resistance, and long service life. However, in reality, because the compressive modulus of rubber is much higher than its shear modulus, it is difficult for rubber vibration dampers to achieve isotropic stiffness. Furthermore, the reciprocating deformation of the rubber caused by high-magnitude vibration loads can easily damage the rubber body of the damper, thus failing to meet the requirements for fatigue resistance and long service life.

[0055] Inertial navigation systems operate in environments ranging from -55℃ to +85℃. The rubber materials used in vibration dampers for these systems are temperature-sensitive, exhibiting significant changes in resonant frequency, amplification, and damping efficiency within this temperature range. Particularly at -55℃, the resonant frequency of the damper increases sharply, while the damping efficiency decreases drastically, leading to decreased accuracy and even reduced lifespan of the inertial navigation system in low-temperature environments.

[0056] As the demands on aircraft to fly higher, farther, and faster become increasingly stringent, the magnitude of airframe vibrations is increasing, requiring longer lifespans for vibration dampers. The performance stability within the -55℃ to +85℃ temperature range is also facing increasingly stringent requirements, demanding that the resonant frequency of the vibration damper at -55℃ be as low as possible compared to room temperature. Existing rubber vibration dampers exhibit resonant frequencies and vibration transmissibility at low temperatures, and resonant frequencies and resonance point amplification factors at high temperatures, all exceeding the technical requirements of inertial navigation systems. Therefore, there is an urgent need to develop wide-temperature-range, long-life rubber vibration dampers to ensure the accuracy and service life of inertial navigation systems at operating temperatures.

[0057] The first aspect of the present invention provides a rubber composition for vibration dampers, which can be applied to the preparation of rubber vibration dampers for aerospace inertial navigation systems, thereby realizing the preparation of rubber vibration dampers with a wide temperature range and long service life.

[0058] The rubber composition for shock absorbers in this invention comprises the following raw materials in parts by weight: 90-110 parts of phenyl silicone rubber, 50-70 parts of reinforcing filler, 10-15 parts of structure control agent, 5-10 parts of functional additives, and 0.6-1 parts of vulcanizing agent.

[0059] In this embodiment of the invention, phenyl silicone rubber is used as the main material, combined with functional additives, reinforcing fillers, structural control agents and vulcanizing agents, which helps to expand the effective damping temperature range of traditional vibration dampers, improve the dynamic fatigue life of rubber materials, and is suitable for wide temperature range and long life rubber vibration dampers, ensuring the reasonable usability of various performance characteristics of vibration dampers under wide temperature range conditions.

[0060] In some embodiments, the weight parts of phenyl silicone rubber may be one of 90 parts, 91 parts, 92 parts, 93 parts, 94 parts, 95 parts, 96 parts, 97 parts, 98 parts, 99 parts, 100 parts, 101 parts, 102 parts, 103 parts, 104 parts, 105 parts, 106 parts, 107 parts, 108 parts, 109 parts, or 110 parts, or any value that satisfies the above range.

[0061] In some embodiments, the phenyl silicone rubber is a phenyl silicone rubber material with a molecular weight of 500,000 to 800,000.

[0062] In some embodiments, the phenyl content of the phenyl silicone rubber is 10% to 20%. Exemplarily, the phenyl content of the phenyl silicone rubber can be one of 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, or any value that satisfies the above range.

[0063] In some embodiments, the elastic modulus of the phenyl silicone rubber is 8 MPa to 15 MPa. Exemplarily, the elastic modulus of the phenyl silicone rubber can be one of 8 MPa, 9 MPa, 10 MPa, 11 MPa, 12 MPa, 13 MPa, 14 MPa, and 15 MPa, or any value satisfying the above range.

[0064] In some embodiments, under damping temperature ranges of -55°C to 150°C, the loss factor of phenyl silicone rubber is ≥0.25.

[0065] By using the above-mentioned phenyl silicone rubber as the main material, it helps to expand the effective damping temperature range of traditional vibration dampers, improve the dynamic fatigue life of rubber materials, and make it suitable for wide-temperature-range, long-life rubber vibration dampers, ensuring the reasonable availability of various performance characteristics of vibration dampers under wide-temperature-range conditions.

[0066] In some embodiments, the weight percentage of the reinforcing filler may be one of 50 parts, 51 parts, 52 parts, 53 parts, 54 parts, 55 parts, 56 parts, 57 parts, 58 parts, 59 parts, 60 parts, 61 parts, 62 parts, 63 parts, 64 parts, 65 parts, 66 parts, 67 parts, 68 parts, 69 parts, or 70 parts, or any value that satisfies the above range.

[0067] In some embodiments, the reinforcing filler includes fumed silica, for example, fumed silica.

[0068] In some embodiments, the specific surface area of ​​fumed silica is 150 m². 2 / g~300 m 2 / g. For example, the specific surface area of ​​fumed silica is 150 m² / g. 2 / g、160 m 2 / g、170 m 2 / g、180 m 2 / g、190 m 2 / g、200 m 2 / g、210m 2 / g、220 m 2 / g、230 m 2 / g、240 m 2 / g、250 m 2 / g、260 m 2 / g、270 m 2 / g、280 m 2 / g、290 m 2 / g、300m 2 / g or any value that satisfies the above range.

[0069] By setting the above reinforcing fillers and their weight proportions, the strength and wear resistance of phenyl silicone rubber can be improved.

[0070] In some embodiments, the weight fraction of the structure control agent may be one of 10, 11, 12, 13, 14, or 15 parts, or any value within the range described above.

[0071] In some embodiments, the structure control agent includes hydroxyl silicone oil, for example, hydroxyl silicone oil.

[0072] In some embodiments, the hydroxyl content of the hydroxyl silicone oil is 5% to 10%. Exemplarily, the hydroxyl content of the hydroxyl silicone oil can be one of 5%, 6%, 7%, 8%, 9%, 10%, or any value that meets the above range.

[0073] In some embodiments, the viscosity of the hydroxyl silicone oil is 50 mPa·s to 100 mPa·s. Exemplarily, the viscosity of the hydroxyl silicone oil can be one of 50 mPa·s, 60 mPa·s, 70 mPa·s, 80 mPa·s, 90 mPa·s, 100 mPa·s, or any value satisfying the above range.

[0074] In some embodiments, the hydroxyl silicone oil is a dihydroxyl-terminated silicone oil.

[0075] By setting the structure control agent and its weight percentage, it is helpful to regulate the dispersion state of reinforcing fillers in the rubber compound, prevent the reinforcing fillers from agglomerating, and ensure the fluidity and stability of the rubber compound.

[0076] In some embodiments, the weight parts of the functional additive may be one of 5, 6, 7, 8, 9, or 10 parts, or any value that meets the above range.

[0077] In some embodiments, the functional additives include polyvinyl silicone oils, for example, polyvinyl silicone oils.

[0078] In some embodiments, the vinyl content of the polyvinyl silicone oil is 5% to 10%. Exemplarily, the vinyl content of the polyvinyl silicone oil can be one of 5%, 6%, 7%, 8%, 9%, 10%, or any value that meets the above range.

[0079] In some embodiments, the viscosity of the polyvinyl silicone oil is 1000 mPa·s to 5000 mPa·s. Exemplarily, the viscosity of the polyvinyl silicone oil can be one of 1000 mPa·s, 2000 mPa·s, 3000 mPa·s, 4000 mPa·s, 5000 mPa·s, or any value satisfying the above range.

[0080] By setting the above functional additives and their weight proportions, it is helpful to expand the effective damping temperature range of traditional vibration dampers, improve the dynamic fatigue life of rubber materials, and make them suitable for wide-temperature-range, long-life rubber vibration dampers, ensuring the reasonable usability of various performance characteristics of vibration dampers under wide-temperature-range conditions.

[0081] In some embodiments, the weight parts of the vulcanizing agent may be one of 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1 part, or any value that meets the above range.

[0082] In some embodiments, the vulcanizing agent includes 2,4-di-tert-butyl peroxide (BIPB), for example, 2,4-di-tert-butyl peroxide.

[0083] By setting the above vulcanizing agents and their weight proportions, it is helpful to initiate the cross-linking reaction of rubber molecules, so that the linear raw rubber molecules form a three-dimensional network structure.

[0084] In some embodiments, the rubber composition for shock absorbers further includes 0.5 to 1 part of pigment. Exemplarily, the weight parts of pigment may be one of 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, or 1 part, or any value satisfying the above range.

[0085] In some embodiments, the pigment comprises chromium trioxide, for example, chromium trioxide.

[0086] The addition of these pigments helps to adjust the color of the adhesive, meeting the needs of practical applications.

[0087] In some embodiments, the rubber composition for shock absorbers comprises the following raw materials in parts by weight: 90-110 parts of phenyl silicone rubber, 50-70 parts of reinforcing filler, 10-15 parts of structural control agent, 5-10 parts of functional additive, 0.6-1 part of vulcanizing agent, and 0.5-1 part of pigment.

[0088] In some embodiments, the rubber composition for shock absorbers comprises the following raw materials in parts by weight: 100 parts of phenyl silicone rubber, 60 parts of reinforcing filler, 12 parts of structural control agent, 8 parts of functional additive, 0.8 parts of vulcanizing agent, and 0.5 parts of pigment.

[0089] Vibration dampers for aircraft inertial navigation systems (INS) need to avoid the resonant frequency of the INS. They must possess multi-directional load-bearing and vibration-damping capabilities, as well as triaxial equal stiffness, and their dynamic performance must remain relatively stable over a wide temperature range. However, existing rubber vibration dampers often cannot simultaneously meet the technical requirements of vibration damping, load bearing, and triaxial equal stiffness. Furthermore, in wide temperature range environments (especially low temperatures), the resonant frequency is high, and the transmissibility at the resonance point frequently exceeds the acceptable technical specifications of the aircraft's inertial navigation system, failing to meet the vibration damping requirements under harsh conditions in a wide temperature range.

[0090] It is worth mentioning that "three directions" refers to the three-dimensional orthogonal directions in space, namely the three axes (X-axis, Y-axis, and Z-axis) of the Cartesian coordinate system commonly used in the industrial field, which correspond to the "front and back (X-axis), left and right (Y-axis), and up and down (Z-axis)" in actual physical space, covering all spatial motion dimensions.

[0091] Specifically, X-axis: usually refers to the "axial direction" of the vibration damper (such as the front-to-back direction after the inertial navigation system is installed, or the direction of the main axis of the vibration damper). Y-axis: lateral (the horizontal direction perpendicular to the X-axis, such as the left-to-right direction). Z-axis: vertical (the vertical direction perpendicular to both the X and Y directions, such as the up-down direction). These three directions are perpendicular to each other, together covering all possible vibration and load directions in space without omission.

[0092] "Each axis" refers to a three-dimensional spatial direction (X, Y, Z axes, i.e., front and back, left and right, up and down), rather than a single direction.

[0093] The second aspect of the present invention provides a rubber vibration damper for an aircraft inertial navigation system. The key feature is that the vibration damper contains a rubber connector formed by vulcanization of the rubber composition for vibration dampers described in the first aspect, and the rubber connector, metal core, and metal base are co-vulcanized to form the vibration damper.

[0094] See Figures 1 to 3 As shown, the rubber vibration damper 100 for an aerospace inertial navigation system of the present invention includes a metal core 10 having a first boss 11, a metal base 20 having a second boss 21, and a rubber connector 30 disposed between the metal core 10 and the metal base 20. The second boss 21 of the metal base 20 and at least the first boss portion of the metal core 10 are embedded inside the rubber connector 30. The rubber connector 30 is formed by vulcanization using the vibration damper rubber composition described in the first aspect as raw material, and the rubber connector 30 is co-vulcanized with the metal core 10 and the metal base 20 to form the vibration damper 100. The vibration level RMS of the working environment of the vibration damper 100 is 19 g to 21 g, and the working time is not less than 10 h per axial direction. And / or, the working temperature of the vibration damper 100 is -55℃ to 85℃.

[0095] In this embodiment of the invention, phenyl silicone rubber (especially medium phenyl silicone rubber) is used as the main material, combined with functional additives, reinforcing fillers, structural control agents and vulcanizing agents, thereby expanding the effective damping temperature range of traditional vibration dampers, improving the dynamic fatigue life of rubber materials, and making it suitable for wide temperature range and long life rubber vibration dampers, ensuring the reasonable usability of various performance characteristics of vibration dampers under wide temperature range conditions.

[0096] RMS, or Root Mean Square, is a core indicator for measuring the intensity of random vibration. It objectively reflects the actual energy of the vibration, rather than its instantaneous peak value. 19 g to 21 g indicates that the RMS value of the vibration acceleration falls within this range, representing a high-intensity vibration environment. This directly determines the design strength of the vibration damper. The vibration damper in this invention possesses sufficient damping capacity and structural stiffness. Furthermore, the vibration damper can operate continuously for at least 10 hours in each axial high-intensity vibration environment, meeting the durability requirements for long-term stable operation.

[0097] The vibration damper 100 of this invention has an operating temperature of -55℃ to 85℃, meaning that the vibration damper 100 can withstand a minimum ambient temperature of -55℃ and a maximum ambient temperature of 85℃. This meets the technical requirements for a wide temperature range of rubber vibration dampers 100 used in aerospace inertial navigation systems and overcomes the shortcomings of low-temperature environments, especially at -55℃, where the peel strength of the metal-rubber interface decreases significantly and the rubber stiffness decreases significantly after vibration cycles (durability fatigue).

[0098] In some embodiments, the weight of a single shock absorber 100 does not exceed 18 g, that is, the maximum weight of a single shock absorber 100 (including all components) is 18 g, which must meet the requirements of lightweight assembly, and is especially suitable for weight-sensitive scenarios, such as aerospace and precision instruments, to avoid affecting the load capacity, endurance or accuracy of the equipment due to excessive weight of the shock absorber.

[0099] In some embodiments, the total height of the vibration damper 100 is 15.5 mm, that is, the overall vertical height of the vibration damper 100 (including all components) is 15.5 mm. It is a low-profile design that can adapt to compact installation space, while balancing the damping stroke and structural stability, meeting the miniaturization requirements of precision equipment such as aerospace inertial navigation.

[0100] In some embodiments, a first annular rubber groove 31 is provided on the side of the rubber connector 30 away from the metal base 20, and the first boss 11 is inserted into the first annular rubber groove 31 to achieve a tight connection between the rubber connector 30 and the metal core 10.

[0101] See Figure 3As shown, the rubber connector 30 has an internal cavity, and a first port and a second port communicating with the cavity are opened on opposite sides of the rubber connector 30. The metal core 10 is located near the first port of the cavity, and at least the first boss 11 of the metal core 10 is embedded in the cavity through the first port. A first annular rubber groove 31 is opened in the cavity to be inserted and connected to the first boss 11, thus achieving a tight connection between the rubber connector 30 and the metal core 10.

[0102] In some embodiments, the first boss 11 is annular and is disposed circumferentially on the outer surface of the metal core 10.

[0103] Specifically, the metal core 10 has a columnar core body, and an annular first protrusion 11 is radially sleeved on the outside of the columnar core body.

[0104] See also Figure 3 As shown, the first protrusion 11 is located at the middle position of the columnar core. It can be understood that at least the bottom of the columnar core and the first protrusion 11 are embedded in the receiving cavity, and the bottom edge of the columnar core is inclined outward and extends downward to form a third protrusion 12. A third annular rubber groove 33 is provided in the receiving cavity to be inserted and connected to the third protrusion 12.

[0105] In some embodiments, the metal core 10 has a through threaded hole 13 inside, and the extension direction of the threaded hole 13 is the same as the through direction of the receiving cavity.

[0106] Specifically, the threaded hole 13 is opened in the height direction or axial direction of the cylindrical core.

[0107] In some embodiments, the threaded hole 13 can be machined or adapted to threads of M3 to M6 specifications, such as threads of M3, M4, M5, and M6.

[0108] See also Figure 3 As shown, the second protrusion 21 is a hollow cylinder and is located on the side of the metal base 20 near the rubber connector 30. Specifically, the hollow cylindrical second protrusion 21 is located near the second port of the receiving cavity. A second annular rubber groove 32 is provided on the side wall of the rubber connector 30. The second protrusion 21 is inserted into the second annular rubber groove 32, thus achieving a tight connection between the rubber connector 30 and the metal base 20.

[0109] In some embodiments, the metal base 20 has a through hole extending through its thickness direction, the second boss 21 is connected to the through hole, and the through hole is connected to the receiving cavity.

[0110] In some embodiments, the height of the second boss is 3 mm to 5 mm. Exemplarily, the height of the second boss can be one of 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, or any value that satisfies the above range.

[0111] In some embodiments, the thickness of the metal base is 2 mm to 3 mm. Exemplarily, the thickness of the metal base can be one of 2 mm, 2.2 mm, 2.5 mm, 2.8 mm, 3 mm, or any value within the above range.

[0112] In some embodiments, the metal base 20 is provided with mounting holes 22, through which the metal base 20 is connected to the outer casing, and the metal core is connected to the inertial measurement unit (IMU) system; or, the metal base 20 is connected to the IMU system through the mounting holes 22, and the metal core 10 is connected to the outer casing. Both mounting methods are acceptable.

[0113] See Figure 2 As shown, there are two mounting holes 22, which are symmetrically arranged on both sides of the second boss 21. The distance between the centers of the two mounting holes 22 is 45 mm to 50 mm. For example, the distance between the centers of the two mounting holes 22 can be one of 45 mm, 46 mm, 47 mm, 48 mm, 49 mm, or 50 mm, or any value that satisfies the above range.

[0114] In some embodiments, the diameter of each mounting hole 22 is 3.5 mm.

[0115] The third aspect of this invention provides a method for preparing a rubber vibration damper for an aerospace inertial navigation system as described in the second aspect. The key to this method is that the rubber composition for the vibration damper described in the first aspect is first mixed and then sheeted to obtain a mixed rubber compound; the mixed rubber compound is rolled into a sheet and cut into a rubber blank; a metal core and a metal base are provided, an adhesive is coated onto the metal core and the metal base, and the sheets are dried; the mold for forming the vibration damper is preheated; the adhesive-coated metal core, the metal base, and the rubber blank are placed in the preheated mold for vulcanization molding; after vulcanization molding is completed, the mold is removed to obtain the vibration damper.

[0116] See Figure 4 As shown, the preparation method of the rubber vibration damper for the aviation inertial navigation system provided by the present invention is carried out in accordance with the following steps.

[0117] S1: Weigh the phenyl silicone rubber according to the required weight parts, and plasticize the phenyl silicone rubber in a two-roll mill until a uniformly plasticized rubber compound is obtained.

[0118] S2: Add the required weight proportions of reinforcing filler, structure control agent, and functional additives to the rubber compound in multiple batches. After the compound has been fully absorbed, add the vulcanizing agent and pigment. Continue until the surface of the rubber compound is smooth, then pass through the vulcanizing agent 3 to 5 times to ensure that all components are mixed more evenly at the molecular level, thus ensuring that the product performance such as hardness, strength, and damping characteristics are consistent after subsequent vulcanization.

[0119] S3: Adjusting the roller gap and blanking: Press the mixed rubber compound into a sheet of uniform thickness, remove the sheet from the rubber mixing mill (sheeting), and cut it into a shape suitable for the mold cavity (blanking) to ensure that the blank can fill the mold smoothly and avoid defects such as insufficient rubber and air bubbles after vulcanization.

[0120] In some embodiments, the film thickness is 3 mm to 8 mm. Exemplarily, the film thickness can be one of 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, or any value within the above range.

[0121] In some embodiments, the weight of the blank or rubber blank is 10 g, for later use. By accurately weighing and controlling the weight of the blank, the amount of rubber in each blank is ensured to be consistent.

[0122] S4: Clean the metal core 10 and the metal base 20, let them dry, and then apply thermosetting silicone rubber adhesive along the surface of the metal core 10 and the metal base 20 to make the adhesive evenly applied to the surface of the metal core 10 and the metal base 20, and then perform drying treatment.

[0123] In some embodiments, the drying process can be carried out in an oven at a temperature of 105°C ± 5°C for a time of 10 min ± 1 min.

[0124] In some embodiments, the drying temperature may be one of 100°C, 105°C, or 110°C, or any value within the range described above. The drying time may be one of 9 min, 10 min, or 11 min, or any value within the range described above.

[0125] S5: Place the mold used to form the shock absorber on the plate of the flat vulcanizing machine, turn on the flat vulcanizing machine, set the temperature of the flat vulcanizing machine to 170℃±3℃, and the pressure to 10 MPa±2 MPa, close the mold and preheat the mold, and the preheating time shall not be less than 30 minutes.

[0126] In some embodiments, the preheating temperature of the mold can be one of 167°C, 170°C, 173°C, or any value within the above range. The pressure can be one of 8 MPa, 9 MPa, 10 MPa, 11 MPa, 12 MPa, or any value within the above range. The preheating time can be 30 min, 35 min, 40 min, etc.

[0127] S6: Place the metal core 10 and metal base 20 in the corresponding positions in the preheated mold, put the weighed rubber blank into the preheated mold cavity, close the mold and place it on a flat vulcanizing machine for molding vulcanization, vent the air 3 to 5 times, and then pressurize to the required vulcanization pressure and start timing. The vulcanization pressure is 10 MPa ± 2 MPa and the vulcanization time is 15 min ± 2 min.

[0128] In some embodiments, the number of times the exhaust is 3, 4, or 5.

[0129] In some embodiments, the vulcanization pressure may be one of 8 MPa, 9 MPa, 10 MPa, 11 MPa, 12 MPa or any value that satisfies the above range.

[0130] In some embodiments, the vulcanization time may be one of 13 min, 14 min, 15 min, 16 min, or 17 min, or any value that satisfies the above range.

[0131] S7: After the vulcanization time is reached, remove the mold from the flat vulcanizing machine, open the mold, and take out the product, i.e., the shock absorber 100.

[0132] S8: Use a utility knife to remove excess adhesive from the surface and holes of the metal core 10 and metal base 20 of the shock absorber 100, while avoiding scratching the rubber with the knife blade.

[0133] Unless otherwise defined, the technical terms used in the following embodiments have the same meaning as commonly understood by those skilled in the art. Unless otherwise specified, the experimental reagents used in the following embodiments are all conventional biochemical reagents; the raw materials, instruments, and equipment used in the following embodiments can all be obtained commercially or by existing methods; unless otherwise specified, the amounts of experimental reagents used are the amounts used in conventional experimental operations; unless otherwise specified, the experimental methods are conventional methods. It should be further noted that the following description is merely exemplary and not a specific limitation of the present invention.

[0134] Example 1 The rubber composition for vibration dampers comprises the following raw materials in parts by weight: 100 parts of phenyl silicone rubber, 60 parts of fumed silica, 12 parts of dihydroxyl-terminated silicone oil, 8 parts of polyvinyl silicone oil, 0.8 parts of BIPB, and 0.5 parts of chromium trioxide. The phenyl silicone rubber has a molecular weight of 500,000 to 800,000, a phenyl content of 10% to 20%, an elastic modulus of 8 MPa to 15 MPa, and a loss factor ≥0.25 under a damping temperature range of -55℃ to 150℃. The fumed silica has a specific surface area of ​​150 m². 2 / g~300 m 2 / g; the hydroxyl content of the dihydroxyl-terminated silicone oil is 5%~10%, and the viscosity is 50 mPa·s~100 mPa·s; the vinyl content of the polyvinyl silicone oil is 5%~10%, and the viscosity is 1000 mPa·s~5000 mPa·s.

[0135] See Figures 1 to 3 As shown, the rubber vibration damper 100 for an aircraft inertial navigation system includes a metal core 10 with a first boss 11, a metal base 20 with a second boss 21, and a rubber connector 30 disposed between the metal core 10 and the metal base 20. The second boss 21 of the metal base 20 and the first boss 11 and third boss 12 of the metal core 10 are embedded inside the rubber connector 30 and respectively plugged into and connected with the second annular rubber groove 32, the first annular rubber groove 31, and the third annular rubber groove 33. The raw material of the rubber connector 30 is the aforementioned rubber composition for vibration dampers, and the rubber connector 30 is co-vulcanized with the metal core 10 and the metal base 20 to form the vibration damper 100.

[0136] The total height of the damper 100 is 15.5 mm, the thickness of the metal base 20 is 2.5 mm, the diameter of the mounting hole 22 on the metal base 20 is 3.5 mm, the distance between the centers of the two mounting holes 22 is 48 mm, and the threaded hole 13 of the metal core 10 can be machined or adapted to M3~M6 thread specifications.

[0137] See Figure 4 As shown, the manufacturing method of a rubber vibration damper for an aircraft inertial navigation system includes the following steps: (1) Plasticizing: Weigh the phenyl silicone rubber with an electronic scale or electronic balance, and plasticize the phenyl silicone rubber with a two-roll mill for 10 min to remove the structure of the silicone rubber itself.

[0138] (2) Mixing: Weigh each material according to the formula using an electronic scale or electronic balance, turn on the cooling water of the open mill, adjust the roller gap of the two-roll rubber mixing mill so that the rubber material wraps around the rollers and keeps a small amount of residual rubber between the two rollers. Add fumed silica, dihydroxy end-capped silicone oil and polyvinyl silicone oil in multiple batches. After the material is fully absorbed, add BIPB and chromium trioxide. When the surface of the rubber material is smooth, tighten the roller gap. After passing through the thin sheet 5 times, it is sheeted out.

[0139] (3) Blank making: Adjust the roller gap, visually measure the thickness of the rubber material to be 4 mm, then cut the rubber sheet to obtain the blank, and weigh the blank to reach 10 g for later use.

[0140] (4) Apply adhesive: Clean the metal core 10 and the metal base 20, and after drying, use a No. 4 brush to apply the thermosetting silicone rubber adhesive along the surface of the metal core 10 and the metal base 20. After applying evenly, put them in an explosion-proof oven to dry. Treat at 105℃ for 10 min, and then take out the metal core 10 and the metal base 20.

[0141] (5) Mold preheating: Place the mold of the pressing damper on the plate of the flat vulcanizing machine, set the temperature of the flat vulcanizing machine to 170℃ and the pressure to 10 MPa, close the mold and preheat the mold for 40 min.

[0142] (6) Vulcanization: Open the flat vulcanizing machine, take out the preheated mold, fix the metal core 10 and the metal base 20 in the mold, put the billet into the preheated mold cavity, press it with tweezers, close the mold, place the mold on the flat vulcanizing machine for molding, vent the air 3 times before molding, then press it to 10 MPa, start the vulcanization time, and the vulcanization time is 15 min.

[0143] (7) Demolding: After vulcanization, remove the mold from the flat vulcanizing machine, use a pry bar to shake the mold up and down at the groove part, open the mold, and remove the damper 100.

[0144] (8) Trimming: Use a utility knife to remove excess adhesive from the surface and holes of the metal core 10 and metal base 20 of the shock absorber 100, while avoiding scratching the rubber with the knife blade.

[0145] Performance testing According to the technical requirements, the performance of the rubber vibration damper 100 for the aerospace inertial navigation system prepared in Example 1 was tested. The test items included resonant frequency, resonant point amplitude amplification factor, functional vibration, and durability vibration test.

[0146] (i) According to the technical requirements, a functional vibration test was conducted on the vibration damper 100 in Example 1. Each axial vibration lasted for 1 hour. After the vibration was completed, the vibration damper 100 was required to be free from defects such as cracking and delamination, and the X, Y, and Z resonant frequencies of the vibration damper 100 at room temperature should meet 70 Hz ± 5 Hz; the X, Y, and Z amplification factors at room temperature should meet 3 to 7. The functional vibration test spectrum is shown in Table 1 below.

[0147] Table 1 Functional vibration test spectrum

[0148] (ii) According to the technical requirements, a durability vibration test was conducted on the vibration damper 100 in Example 1, with each axial vibration lasting 10 hours. After the vibration was completed, the vibration damper 100 was required to be free from defects such as cracking and delamination. The durability vibration test spectrum is shown in Table 2 below.

[0149] Table 2 Durability vibration test spectrum

[0150] (III) The resonant frequency of the vibration damper 100 in Example 1 was tested. The test items included: 1) Resonant frequencies in the X, Y, and Z directions at room temperature; 2) Resonant frequencies in the X, Y, and Z directions throughout the entire temperature range (-55℃ to +85℃). The test results are shown in Table 3.

[0151] Table 3. Test results of the resonant frequency of the rubber vibration damper used in the aerospace inertial navigation system in Example 1.

[0152] Note: The test frequency is 20 Hz to 2000 Hz, the vibration magnitude is 2 g, and the single-pass scan is 10 min.

[0153] As can be seen from the results in Table 3, the vibration damper 100 of the present invention has a resonant frequency of 70 Hz ± 5 Hz in the X, Y, and Z directions at a normal temperature of 25℃; a resonant frequency of 60 Hz to 120 Hz in the X, Y, and Z directions at a full temperature range of -55℃ to +85℃; and a maximum difference of ≤ 8 Hz in the resonant frequency range of the X, Y, and Z directions at a full temperature range of -55℃ to +85℃.

[0154] (iv) According to the technical requirements, the amplitude amplification factor at the resonant point of the vibration damper 100 in Example 1 was tested. The test items were: full temperature (-55℃~+85℃), amplification factor in the X, Y, and Z directions. The test results are shown in Table 4 below.

[0155] Table 4. Test results of the amplitude amplification factor at the resonant point of the vibration damper in Example 1.

[0156] Note: The test frequency is 20 Hz to 2000 Hz, the vibration magnitude is 2 g, and the single-pass scan is 10 min.

[0157] As can be seen from the test results in Table 4, the vibration damper of this invention has an amplification factor of 3 to 7 in the X, Y, and Z directions at a full temperature range of -55℃ to +85℃.

[0158] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A rubber composition for a vibration damper, characterized in that, Including the following raw materials by weight: 90-110 parts of phenyl silicone rubber, 50-70 parts of reinforcing filler, 10-15 parts of structure control agent, 5-10 parts of functional additives, and 0.6-1 part of vulcanizing agent.

2. The rubber composition for vibration dampers as described in claim 1, characterized in that, The phenyl silicone rubber has a molecular weight of 500,000 to 800,000, and the phenyl content of the phenyl silicone rubber is 10% to 20%; and / or, The elastic modulus of the phenyl silicone rubber is 8 MPa to 15 MPa; and / or, Under damping temperature range of -55℃ to 150℃, the loss factor of the phenyl silicone rubber is ≥0.

25.

3. The rubber composition for vibration dampers as described in claim 1, characterized in that, The reinforcing filler includes fumed silica, which has a specific surface area of ​​150 m². 2 / g~300 m 2 / g; Preferably, the structure control agent comprises hydroxyl silicone oil, wherein the hydroxyl content of the hydroxyl silicone oil is 5% to 10%, and / or the viscosity of the hydroxyl silicone oil is 50 mPa·s to 100 mPa·s; Preferably, the hydroxyl silicone oil is a dihydroxyl-terminated silicone oil.

4. The rubber composition for a shock absorber as described in claim 1, characterized in that, The functional additives include polyvinyl silicone oil, wherein the vinyl content of the polyvinyl silicone oil is 5% to 10%, and / or the viscosity of the polyvinyl silicone oil is 1000 mPa·s to 5000 mPa·s; Preferably, the vulcanizing agent comprises 2,4-di-tert-butylperoxide cumene.

5. The rubber composition for a shock absorber as described in claim 1, characterized in that, The rubber composition for the shock absorber further includes: 0.5 to 1 part of pigment; Preferably, the pigment comprises chromium trioxide.

6. A rubber vibration damper for an aircraft inertial navigation system, characterized in that, It includes a metal core having a first protrusion, a metal base having a second protrusion, and a rubber connector disposed between the metal core and the metal base, wherein the second protrusion of the metal base and at least the first protrusion of the metal core are embedded inside the rubber connector. Wherein, the raw material of the rubber connector is the rubber composition for shock absorbers according to any one of claims 1 to 5, and the rubber connector is co-vulcanized with the metal core and the metal base to form the shock absorber; The vibration damper operates in an environment with an RMS vibration level of 19 g to 21 g and an operating time of not less than 10 h per axial direction; and / or, the vibration damper operates at a temperature of -55℃ to 85℃.

7. The rubber vibration damper for an aerospace inertial navigation system as described in claim 6, characterized in that, The rubber connector has an internal cavity, and a first port and a second port communicating with the cavity are provided on opposite sides of the rubber connector. At least a first boss portion of the metal core is embedded in the cavity through the first port. A first annular rubber groove is provided in the cavity to be inserted and connected to the first boss. Preferably, the metal core has a columnar core body, and the first boss is annular and sleeved on the outside of the columnar core body; Preferably, the metal core has a through threaded hole inside, and the extension direction of the threaded hole is the same as the through direction of the receiving cavity; Preferably, the first protrusion is located at the middle position of the columnar core, the bottom of the columnar core and the first protrusion are embedded in the receiving cavity, and the bottom edge of the columnar core is inclined outward and extends downward to form a third protrusion. A third annular rubber groove is provided in the receiving cavity to be inserted and connected to the third protrusion. Preferably, the total height of the shock absorber is 15.5 mm; Preferably, the weight of a single shock absorber does not exceed 18 g.

8. The rubber vibration damper for an aerospace inertial navigation system as described in claim 7, characterized in that, The second boss is in the shape of a hollow cylinder and is disposed on the side of the metal base near the rubber connector, preferably near the second port side of the receiving cavity; a second annular rubber groove is formed on the side wall of the rubber connector, and the second boss is inserted into the second annular rubber groove. Preferably, the metal base has a through hole extending through its thickness direction, the second boss is connected to the through hole, and the through hole is connected to the receiving cavity; Preferably, the height of the second boss is 3 mm to 5 mm, and / or the thickness of the metal base is 2 mm to 3 mm; Preferably, the metal base is provided with mounting holes, the metal base is connected to the outer casing through the mounting holes, and the metal core is connected to the IMU system; or, the metal base is connected to the IMU system through the mounting holes, and the metal core is connected to the outer casing. Preferably, there are two mounting holes, which are symmetrically arranged on both sides of the second boss, and the distance between the centers of the two mounting holes is 45 mm to 50 mm. Preferably, the diameter of the mounting hole is 3.5 mm.

9. A method for manufacturing a rubber vibration damper for an aircraft inertial navigation system according to any one of claims 6 to 8, characterized in that, Includes the following steps: The shock absorber according to any one of claims 1 to 5 is mixed with the rubber composition and sheeted out to obtain the mixed rubber; The compounded rubber is rolled into a sheet and cut into a rubber blank; A metal core and a metal base are provided, an adhesive is applied to the metal core and the metal base, and then the materials are dried. Preheat the mold used to form the vibration damper; The metal core, the metal base, and the rubber blank coated with adhesive are placed in a preheated mold for vulcanization molding; After vulcanization molding is completed, the mold is removed to obtain the shock absorber.

10. The preparation method according to claim 9, characterized in that, The preheating temperature of the mold is 170℃±3℃, the pressure is 10 MPa±2 MPa, and the preheating time is not less than 30 min. Preferably, the vulcanization molding includes: after the mold is closed, compression vulcanization is performed, venting is performed 3 to 5 times, and then the pressure is increased to the vulcanization pressure of 10 MPa ± 2 MPa before timing is started, and the vulcanization time is 15 min ± 2 min. Preferably, the drying temperature of the metal core and the metal base after coating with adhesive is 105℃±5℃, and the drying time is 10 min±1 min.

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