A damper

Abstract

The application discloses a damper and relates to the technical field of pipeline vibration control, and aims to solve the technical problem of how to improve the vibration suppression of a pipeline multi-degree-of-freedom space. The damper comprises a first cylinder body, the first cylinder body is provided with a containing cavity, and the containing cavity is used for containing damping medium; a plunger is partially located in the containing cavity, the plunger comprises a first end and a second end which are opposite to each other, the first end is suitable for being connected with a pipeline to be damped, and the second end is located in the containing cavity and is immersed in the damping medium; wherein, there is a movable gap between the outer peripheral wall of the plunger and the inner peripheral wall of the containing cavity and between the second end of the plunger and the bottom wall of the containing cavity.

Description

Technical Field

[0001] This application relates to the field of pipeline vibration control technology, and in particular to a damper. Background Technology

[0002] In industrial pipeline systems, small-diameter pipes with a diameter of less than DN50mm or large-diameter thin-walled pipes are at higher risk of vibration fatigue failure due to their low stiffness and easy coupling with excitation sources.

[0003] In related technologies, dampers used for pipeline vibration reduction often employ a single translational degree of freedom. The damping force acts only on the displacement component in the direction of the damper's axis, failing to effectively constrain other translational degrees of freedom, thus making it impossible to effectively dissipate the total energy of the pipeline's spatial vibration. Summary of the Invention

[0004] The purpose of this application is to provide a damper that addresses the technical problem of how to improve the suppression of vibrations in a multi-degree-of-freedom space of a pipeline.

[0005] To achieve the above objectives, the embodiments of this application adopt the following technical solutions: According to a first aspect of this application, a damper is provided, comprising: A first cylinder body, the first cylinder body having a receiving cavity for accommodating a damping medium; A plunger, the plunger portion being located within the receiving cavity, the plunger including a first end and a second end facing away from each other, the first end being adapted to be connected to the pipe to be damped, and the second end being located within the receiving cavity and immersed in the damping medium; There are movable gaps between the outer peripheral wall of the plunger and the inner peripheral wall of the receiving cavity, and between the second end of the plunger and the bottom wall of the receiving cavity.

[0006] The damper provided in this application embodiment immerses the second end of the plunger in a damping medium, and the first end is adapted to be connected to the pipeline to be damped. Since there are movable gaps between the outer peripheral wall of the plunger and the inner peripheral wall of the receiving cavity, as well as between the second end and the bottom wall of the receiving cavity, the vibration components of the plunger in each of the four degrees of freedom (up, down, left, right, front, and back) can be subjected to the damping force of the damping medium, thereby achieving total energy dissipation of complex spatial vibration and comprehensively suppressing the vibration amplitude of the pipeline.

[0007] In some embodiments, the plunger includes a damping section along the axial direction, the damping section being immersed in the damping medium, and the outer wall of the damping section is provided with a plurality of first inner grooves and / or blind holes.

[0008] In some embodiments, the plunger is provided with a plurality of through holes along the axial direction, the through holes passing through the first end and the second end.

[0009] In some embodiments, the first end of the plunger is further provided with a second inner groove, the through hole communicates with the second inner groove, and the side wall of the plunger is provided with a pressure balance hole that communicates with the second inner groove.

[0010] In some embodiments, a connecting plate is also included, wherein the first end of the plunger is connected to the connecting plate, and the side of the connecting plate opposite to the plunger is adapted to be connected to the pipe to be vibration-damped.

[0011] In some embodiments, a dustproof component is further provided between the connecting plate and the first cylinder body, and the dustproof component is spaced apart around the plunger.

[0012] In some embodiments, the dustproof assembly includes a dust cover with an annular structure, one axial end of the dust cover being connected to the first cylinder body, and the other axial end of the dust cover being connected to the connecting plate.

[0013] In some embodiments, the dustproof assembly further includes a second cylinder and fasteners; The second cylinder is fixed to the connecting plate, the second cylinder is disposed opposite to the first cylinder, and there is a first gap between the second cylinder and the first cylinder; The dust cover is installed around the first cylinder and the second cylinder and covers the first gap; The fasteners are used to fix the two ends of the dust cover axially to the first cylinder and the second cylinder, respectively.

[0014] In some embodiments, the peripheral surfaces of the first cylinder and the second cylinder are provided with fixing portions, and the fasteners are connected to the fixing portions.

[0015] In some embodiments, a base is also included, the base being connected to the first cylinder body and the base being located on the opening side opposite to the receiving cavity; A connecting bracket is detachably provided between the base and the connecting plate, and the connecting bracket is used to fix the relative position of the plunger and the first cylinder.

[0016] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A cross-sectional view of a damper provided in an embodiment of this application; Figure 2 for Figure 1 An axial sectional view of the plunger in the damper shown. Figure 3 for Figure 2 A magnified view of a portion of region A in the middle; Figure 4 for Figure 1 A three-dimensional view of the plunger in the damper shown; Figure 5 for Figure 4 A magnified view of region B in the plunger shown; Figure 6 for Figure 2 The bottom view of the plunger shown; Figure 7 for Figure 1 A schematic diagram of a modified structure of the damper shown. Figure 8 for Figure 7 A schematic diagram of a modified structure of the damper shown. Figure 9 for Figure 8 A schematic diagram of a fixed structure of the damper shown; Figure 10 for Figure 9 The exploded view of the damper fixing structure shown.

[0019] Figure Labels 1. First cylinder block; 11. Damping medium; 2. Plunger; 21. First end; 22. Second end; 23. Damping section; 231. First inner groove; 232. Blind hole; 24. Through hole; 25. Second inner groove; 26. Pressure balance hole; 3. Connecting plate; 4. Dustproof components; 41. Dust cover; 42. Second cylinder block; 43. Fasteners; 5. Base; 6. Connecting bracket. Detailed Implementation

[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] In the description of this application, it should be understood that the terms "upper," "lower," "left," "right," "front," "rear," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or relative positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and for simplification, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Unless otherwise specified, the above-mentioned orientational descriptions can be flexibly set in practical applications, provided that the relative positional relationships shown in the accompanying drawings are satisfied.

[0022] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0023] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "communication" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. They can refer to a direct connection or an indirect connection through an intermediate medium, or a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0024] In embodiments of this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, article, or apparatus that includes that element.

[0025] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0026] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0027] In the field of pipelines, dampers can be used to reduce pipeline vibration. In related technologies, dampers are mostly unidirectional, such as spring dampers, hydraulic dampers, and friction dampers. However, the damping force of such unidirectional dampers only acts in the axial direction of the damper, and cannot effectively constrain other translational degrees of freedom.

[0028] This application provides a damper for improving vibration suppression in multi-degree-of-freedom spaces of pipelines. Please refer to... Figure 1 , Figure 1 This is a cross-sectional view of a damper provided in an embodiment of this application. In the embodiment of this application, the damper includes a first cylinder 1 and a plunger 2.

[0029] The first cylinder body 1 serves as the main load-bearing shell of the damper, and can be cylindrical, square, or a cavity structure with a receiving chamber. The first cylinder body 1 can be made of metals such as carbon steel, stainless steel, or alloy steel. For example, stainless steel can be used as the material for the first cylinder body 1, as it ensures structural strength and improves corrosion resistance.

[0030] The cavity within the first cylinder 1 is used to house the damping medium 11. The damping medium 11 serves to provide damping force; for example, the damping medium 11 can be a viscous fluid, a composite gel, silicone oil, etc. It is understood that the first cylinder 1 can be a single-piece molded part, or it can be formed by connecting, for example, tubular and plate-like structures.

[0031] The plunger 2 is the core moving component that directly bears the vibration load transmitted by the pipeline to be vibration-damped. The plunger 2 is partially located within the receiving cavity and includes a first end 21 and a second end 22 facing away from each other. The first end 21 is adapted to connect to the pipeline to be vibration-damped, and the second end 22 is located within the receiving cavity and immersed in the damping medium 11. In some embodiments, the connection between the plunger 2 and the pipeline to be vibration-damped can be a rigid connection or a connection via a transition plate 3, flange, clamp, or other components to transmit the swaying, impact, and pulsating displacement of the pipeline to the plunger 2. The plunger 2 can be made of stainless steel or other metal materials that balance structural strength and ease of processing.

[0032] The second end 22 of the plunger 2 is immersed in the damping medium 11, allowing the plunger 2 to undergo relative displacement within the damping medium 11 when subjected to external excitation. This displacement is achieved through compression, shearing, and flow around the plunger, causing the damping medium 11 to generate resistance. For example, when the plunger 2 moves downwards, it compresses and shears the damping medium 11, while the damping medium 11 generates a damping force in the opposite direction. When the plunger 2 moves upwards, the damping medium 11 generates a damping force in the opposite direction. This structural configuration causes the plunger 2 to generate internal resistance within the damping medium 11, thereby converting mechanical vibration into heat dissipation.

[0033] There are movable gaps between the outer peripheral wall of the plunger 2 and the inner peripheral wall of the receiving cavity, and between the second end 22 of the plunger 2 and the bottom wall of the receiving cavity. In some embodiments, the range of the movable gap is [5mm, 15mm]. For example, the movable gap can be 5mm, 10mm, or 15mm. Please continue reading. Figure 1 In the embodiments of this application, the plunger 2 is surrounded by a damping medium 11 on both its periphery and bottom. This means that the plunger 2 in this embodiment does not move in a piston-like reciprocating motion along a single axial direction as is common in related technologies; instead, it possesses the ability for multi-dimensional relative displacement. In other words, in the embodiments of this application, the plunger 2 can vibrate in the axial, lateral, vertical, or combined directions. In this case, the damping medium 11 generates damping force through flow compensation and viscous shear in different directions.

[0034] The damper provided in this embodiment immerses the second end 22 of the plunger 2 in the damping medium 11, and the first end 21 is adapted to be connected to the pipeline to be damped. Since there are movable gaps between the outer peripheral wall of the plunger 2 and the inner peripheral wall of the receiving cavity, as well as between the second end 22 and the bottom wall of the receiving cavity, the vibration components of the plunger 2 in each of the four degrees of freedom directions (up, down, left, right, front, back) can be subjected to the damping force of the damping medium 11, thereby achieving total energy dissipation of complex spatial vibration and comprehensively suppressing the vibration amplitude of the pipeline.

[0035] Please see Figure 2 and Figure 3 , Figure 2 for Figure 1 Axial cross-sectional view of plunger 2 in the damper shown; Figure 3 for Figure 2 A partially enlarged view of region A. In some embodiments, the plunger 2 includes a damping section 23 along the axial direction. The damping section 23 is immersed in the damping medium 11, and a plurality of first inner grooves 231 are provided on the outer wall of the damping section 23. In some embodiments, the length of the damping section 23 is less than the length of the plunger 2 extending into the first cylinder 1. Please refer to... Figure 3 The first inner groove 231 can be arranged at intervals to form a shape similar to the crenellations of a Great Wall with high and low teeth. By setting the first inner groove 231 on the outer wall of the damping section 23, the contact area between the damping medium 11 and the plunger 2 can be increased, so that the damping medium 11 generates more significant viscous shear when the plunger 2 moves, thereby improving the damping energy dissipation capacity per unit displacement. Furthermore, the first inner groove 231 can form local eddy current regions, buffer zones, and fluid retention regions, so that the damping medium 11 generates more complex flow paths under multi-directional vibration, improving the directional adaptability and stability of the damping force.

[0036] Please continue to refer to Figure 4 and Figure 5 , Figure 4 for Figure 1 A three-dimensional view of plunger 2 in the damper shown; Figure 5 for Figure 4 A partially enlarged view of region B in plunger 2 is shown. In some embodiments, the first inner groove 231 can be an annular structure. Furthermore, in other embodiments, blind holes 232 can be provided on the damping band. Please continue reading. Figure 4 and Figure 5 In addition to the first inner grooves 231 spaced apart on the damping band, blind holes 232 can also be provided on the damping band. It is understood that the radial cross-sectional shape of the blind hole 232 includes, but is not limited to, circles, regular polygons, stars, etc. The inner cavity of the blind hole 232 can be cylindrical, conical, frustum-shaped, spherical, etc. In some embodiments, the blind hole 232 can also be a threaded hole. In some embodiments, the blind hole 232 is hexagonal honeycomb-shaped, with an inscribed circle diameter of 1.6 mm, a depth of 2 mm, and a wall thickness of 0.1 mm between holes.

[0037] In the above embodiment, the combination of the first groove and the blind hole 232 can further increase the shear contact area and friction area between the damping medium 11 and the plunger 2, thereby increasing the damping force and improving the vibration reduction effect on medium and high frequency micro-amplitude vibrations and multi-dimensional vibrations.

[0038] In some embodiments, please refer to Figure 2 and Figure 6 , Figure 6 for Figure 2 The image shows a bottom view of the plunger 2. The plunger 2 has several through holes 24 along its axial direction, passing through the first end 21 and the second end 22. In some embodiments, the diameter of the through holes 24 ranges from [2mm, 8mm]. For example, the diameter of the through holes 24 can be 2mm, 4mm, 6mm, or 8mm, and the minimum wall thickness between the holes is not less than 2mm. Furthermore, when the through holes 24 are circular, threads can be further machined on the inner wall of the through holes 24. The cross-section of the threads can be trapezoidal, triangular, rectangular, sawtooth, etc.

[0039] By providing the through hole 24, when the plunger 2 moves, the damping medium 11 near the second end 22 forms a local high-pressure zone due to the compression of the plunger 2. The through hole 24 allows the medium in the high-pressure zone to flow to other areas along the through hole 24 inside the plunger 2, thereby reducing the local pressure peak and reducing the phenomenon of fluid rigid impact. In addition, the through hole 24 itself forms a channel for the damping medium 11. When the damping medium 11 flows in the through hole 24, it will generate additional energy dissipation due to viscous friction, thus helping to improve the damping performance.

[0040] Please continue reading. Figure 2 In some embodiments, the first end 21 of the plunger 2 is further provided with a second inner groove 25, and the through hole 24 communicates with the second inner groove 25. The side wall of the plunger 2 is provided with a pressure balancing hole 26 communicating with the second inner groove 25. For example, the pressure balancing hole 26 can be located at a position 10%-20% of the total height below the top surface of the plunger 2. The pressure balancing holes 26 can be evenly arranged along the axial direction, with a quantity of 4 to 8, and a diameter of 3mm-6mm. Through the provision of the second inner groove 25 and the pressure balancing hole 26, the plunger 2 can quickly balance the fluid pressure in the upper, lower, and inner / outer cavities when moving at high speed, effectively avoiding the generation of empty quadrants due to local pressure imbalance or negative pressure, thereby ensuring the long-term operational stability of the damper.

[0041] Please see Figure 7 , Figure 7 for Figure 1 The diagram shows a modified structure of the damper. In some embodiments, to achieve a more stable, reliable, and convenient mechanical connection between the damper and the external pipeline, and to expand the force-bearing area and improve the force concentration problem at the end of the plunger 2, a connecting plate 3 is also included. The first end 21 of the plunger 2 is connected to the connecting plate 3, and the side of the connecting plate 3 facing away from the plunger 2 is adapted to connect to the pipeline to be damped. For example, the connecting plate 3 can be a plate-shaped, flange-shaped, or ear-shaped structure. In addition, the connection between the connecting plate 3 and the first end 21 forms a buffer cavity with the second inner groove 25. In some embodiments, the total area of ​​the pressure balance hole 26 can be smaller than that of the through hole 24. With this structural form, the plunger 2 vibrates and generates a change in air pressure in the buffer cavity. This change in air pressure in the buffer cavity can also play a certain damping function. That is, through the cooperation of the air in the buffer cavity and the damping medium 11, a liquid + gas joint vibration attenuation mode is formed, thereby further improving the damping effect.

[0042] To reduce or avoid contamination of the damping medium 11 by external factors, please refer to [link / reference]. Figure 8 , Figure 8 for Figure 7 The diagram shows a modified structure of the damper. In the embodiment of this application, a dustproof component 4 is further provided between the connecting plate 3 and the first cylinder 1, and the dustproof component 4 is spaced apart around the plunger 2. It should be noted that the function of the dustproof component 4 is to protect the exposed area of ​​the plunger 2 to prevent external contaminants such as dust, water vapor, particulate impurities, and corrosive media from entering the movement space around the plunger 2 or entering the vicinity of the opening of the first cylinder 1, thereby affecting the damper's movement flexibility, sealing condition, and long-term service life.

[0043] The dustproof component 4 can take various structural forms, such as a flexible dust cover 41, a corrugated cover, a sleeve cover, or a telescopic cover, etc. Please continue reading. Figure 8 In some embodiments, the dustproof assembly 4 includes a dust cover 41, which has an annular structure. One axial end of the dust cover 41 is connected to the first cylinder 1, and the other axial end is connected to the connecting plate 3. The dust cover 41 can be made of a flexible material, such as rubber, polyurethane, silicone, or composite elastic material. For example, the dust cover 41 can be configured as a bellows, with one end connected to the first cylinder 1 and the other end connected to the connecting plate 3, and covering the periphery of the plunger 2. This structural configuration allows the bellows' elasticity to further provide a certain degree of damping force, thereby achieving a composite damping effect of damping medium 11 + air + mechanical damping.

[0044] Please continue reading. Figure 8 In some embodiments, the dustproof assembly 4 further includes a second cylinder 42 and fasteners 43. The second cylinder 42 can be welded or integrally formed onto the connecting plate 3. The second cylinder 42 can be configured to have the same inner diameter and wall thickness as the first cylinder 1, and is coaxially arranged opposite to the first cylinder 1, with a first gap between the second cylinder 42 and the first cylinder 1. The first gap is used to reduce or avoid collisions between the first cylinder 1 and the second cylinder 42 when the plunger 2 vibrates up and down. The dust cover 41 covers the periphery of the first cylinder 1 and the second cylinder 42, and covers the first gap. The fasteners 43 are used to fix the two ends of the dust cover 41 axially to the first cylinder 1 and the second cylinder 42, respectively. It should be noted that the fasteners 43 can be screws, rivets, or clamps, etc. To further improve the fixing effect of the dust cover 41, please refer to [further details needed]. Figure 8 In some embodiments, the peripheral surfaces of the first cylinder 1 and the second cylinder 42 are provided with fixing portions, and fasteners 43 are connected to the fixing portions. For example, the fixing portion may be a rectangular groove provided on the outer wall of the opposite port of the first cylinder 1 and the second cylinder 42. The width of the rectangular groove may be 8mm to 14mm, and the depth may be 2mm to 6mm. The fastener 43 may be a clamp with a width adapted to the rectangular groove. During installation, the lip of the dust cover 41 can be embedded into the rectangular groove and locked in place by the clamp, forming a reliable dustproof and moisture-proof sealing structure.

[0045] Please see Figure 9 and Figure 10 , Figure 9 for Figure 8 A schematic diagram of a fixed structure for the damper shown. Figure 10 for Figure 9An exploded view of the damper fixing structure is shown. In some embodiments, to provide a mounting support base for the damper and to limit and fix the relative position between the plunger 2 and the first cylinder 1 during transportation, installation, maintenance, or non-operating states, the damper in this embodiment further includes a base 5. The base 5 is connected to the first cylinder 1 and is located on the side opposite to the opening of the receiving cavity. It should be noted that the base 5 can be integrally formed with the cylinder, or it can be fixedly connected by welding or other methods. A connecting bracket 6 is also detachably provided between the base 5 and the connecting plate 3. The connecting bracket 6 is used to fix the relative position of the plunger 2 and the first cylinder 1. For example, as shown... Figure 9 As shown, the connecting bracket 6 can be at least three rigid bracket structures with both ends connected to the connecting plate 3 and the base 5 respectively. The connecting bracket 6 can be temporarily fixed by means of screwing, snap-fitting, or magnetic connection, thus achieving precise positioning between the first cylinder 1 and the plunger 2. In actual installation, it can be ensured that the coaxiality error between the plunger 2 and the first cylinder 1 is controlled within 0.5mm. After the damper is installed in place, the connecting bracket 6 is removed, allowing the plunger 2 to move freely relative to the first cylinder 1, and the damper enters the working state.

[0046] The above settings improve the stability and safety of the damper during transportation, installation and maintenance, facilitate on-site positioning and assembly, and ensure that the plunger 2 has sufficient relative mobility during operation, thus achieving a balance between structural protection and functional release.

[0047] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A damper, characterized in that, include: A first cylinder body, the first cylinder body having a receiving cavity for accommodating a damping medium; A plunger, the plunger portion being located within the receiving cavity, the plunger including a first end and a second end facing away from each other, the first end being adapted to be connected to the pipe to be damped, and the second end being located within the receiving cavity and immersed in the damping medium; There are movable gaps between the outer peripheral wall of the plunger and the inner peripheral wall of the receiving cavity, and between the second end of the plunger and the bottom wall of the receiving cavity.

2. The damper according to claim 1, characterized in that, The plunger includes a damping section along the axial direction, the damping section being immersed in the damping medium, and the outer wall of the damping section is provided with a plurality of first inner grooves and / or blind holes.

3. The damper according to claim 1, characterized in that, The plunger has several through holes along the axial direction, and the through holes pass through the first end and the second end.

4. The damper according to claim 3, characterized in that, The first end of the plunger is also provided with a second inner groove, the through hole communicates with the second inner groove, and the side wall of the plunger is provided with a pressure balance hole that communicates with the second inner groove.

5. The damper according to any one of claims 1 to 4, characterized in that, It also includes a connecting plate, the first end of the plunger is connected to the connecting plate, and the side of the connecting plate facing away from the plunger is adapted to be connected to the pipe to be vibration-damped.

6. The damper according to claim 5, characterized in that, A dustproof component is also provided between the connecting plate and the first cylinder body, and the dustproof component is spaced apart around the plunger.

7. The damper according to claim 6, characterized in that, The dustproof assembly includes a dust cover with an annular structure. One end of the dust cover along the axial direction is connected to the first cylinder body, and the other end of the dust cover along the axial direction is connected to the connecting plate.

8. The damper according to claim 7, characterized in that, The dustproof assembly also includes a second cylinder and fasteners; The second cylinder is fixed to the connecting plate, the second cylinder is disposed opposite to the first cylinder, and there is a first gap between the second cylinder and the first cylinder; The dust cover is installed around the first cylinder and the second cylinder and covers the first gap; The fasteners are used to fix the two ends of the dust cover axially to the first cylinder and the second cylinder, respectively.

9. The damper according to claim 8, characterized in that, The first cylinder and the second cylinder are provided with fixing parts on their peripheral sides, and the fasteners are connected to the fixing parts.

10. The damper according to claim 5, characterized in that, It also includes a base, which is connected to the first cylinder body and is located on the opening side opposite to the receiving cavity; A connecting bracket is detachably provided between the base and the connecting plate, and the connecting bracket is used to fix the relative position of the plunger and the first cylinder.

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