Air spring shock absorber fastener

Abstract

The application belongs to the technical field of rail transit damping fasteners, and particularly relates to an air spring damping fastener, which comprises an upper iron pad, an air spring isolator, a lower iron pad, an anchoring system and a spring strip pressing system, wherein the air spring isolator is arranged between the upper iron pad and the lower iron pad and forms a sealed air cavity in the air spring isolator, the air spring isolator provides elastic support and damping effect for the steel rail through compression of the air cavity, the air cavity is communicated with the outside through a valve to realize air pressure adjustment, so as to change the elastic properties of the fastener, and the fastener has adaptive supporting and damping capacity under different load conditions. By introducing the air spring isolator as a core elastic element, the fastener can automatically match the reasonable rigidity under different load conditions, and the damping performance and structural safety are considered at the same time, so that the fastener has good damping effect, load adaptive capacity and engineering application value.

Description

Technical Field

[0001] This invention belongs to the field of rail transit track structure technology, and particularly relates to a track vibration damping fastener for rail transit such as subways and light rails. Background Technology

[0002] With the continuous increase in the scale of urban rail transit construction and operational density, the vibration and noise generated by the interaction between wheels and rails during the operation of subway, light rail and other rail trains are transmitted to the surrounding environment through the track structure, which has an adverse impact on the structural safety of buildings along the line, the operation of precision equipment and the living environment of residents. Track vibration reduction and noise reduction has become one of the important technical issues of common concern in urban rail transit engineering.

[0003] In existing technologies, to reduce the transmission of wheel-rail vibration to the substructure and surrounding environment, vibration damping fasteners are usually installed between the rail and the sleeper or track bed. These fasteners perform basic functions such as positioning the rail, maintaining the track gauge, and limiting longitudinal and lateral displacement. At the same time, they absorb and attenuate the vibration energy generated by the wheel-rail interaction through the deformation of their internal elastic elements. Due to their relatively compact structure and ease of construction and maintenance, they have been widely used in urban rail transit lines such as subways.

[0004] Currently, most mainstream track vibration damping fasteners use solid rubber as the core elastic element. They are usually placed between the iron pads under the rails or integrated inside the fastener body. They utilize the compression or shear deformation of the rubber material under the dynamic load of the train to buffer and dissipate vibration impact through the viscoelastic properties of the material itself, thereby achieving the basic vibration isolation function.

[0005] However, long-term engineering practice has revealed that this type of vibration damping fastener based on solid rubber has certain limitations in terms of vibration damping mechanism, adaptability and durability. Its vibration damping performance is mainly limited by the physical properties of the rubber material itself. Its isolation effect on the low and medium frequency vibrations and impacts that are common in urban rail transit is relatively limited. Its vibration damping frequency band is narrow, and it is difficult to achieve ideal control effect in areas with high vibration damping requirements.

[0006] Meanwhile, the stiffness of solid rubber elastic elements is basically fixed after production and molding, making it difficult to adjust according to changes in load conditions during train operation. Under light or no-load conditions, the fastener system may exhibit excessive overall stiffness, affecting the vibration reduction effect. Under heavy-load conditions, insufficient stiffness may adversely affect the track geometry and stability, thus restricting the fastener's adaptability to complex operating conditions.

[0007] In addition, solid rubber is prone to aging, creep and fatigue damage under long-term alternating loads and environmental factors such as ozone and temperature changes. Its elastic properties and stiffness gradually decrease with the service time, resulting in unstable vibration reduction performance, high maintenance and replacement frequency, which is not conducive to reducing the total life cycle cost of the track structure.

[0008] Therefore, under the existing track vibration damping fastener technology system, how to break through the inherent limitations of traditional solid rubber elastic elements in terms of vibration damping performance, stiffness adaptability and durability, and construct a vibration damping fastener structure that better meets the high standard operation requirements of urban rail transit has become an urgent technical problem to be solved in this field. Summary of the Invention

[0009] This invention aims to solve at least one of the problems of existing track vibration damping fasteners, which mainly rely on solid rubber as the elastic medium, have fixed stiffness, and are difficult to balance light-load vibration damping and heavy-load support. This application provides a vibration damping fastener structure that can automatically adjust its elastic response according to load changes and has post-adjustment capability. It discloses an air spring vibration damping fastener with an air spring isolator as the core elastic support unit, connected in parallel with a limiting pad. By utilizing the compression characteristics of the air cavity to participate in load bearing and vibration damping, a more reasonable stiffness matching relationship is formed under different load conditions. Simultaneously, safety redundancy and a multi-stage buffer structure are introduced, thereby effectively improving vibration damping effect and operational safety while ensuring track structure stability.

[0010] In view of this, the present invention provides an air spring vibration damping fastener, comprising: The upper iron pad, air spring vibration isolator, and lower iron pad are arranged sequentially from top to bottom; Anchoring systems used to secure the entire fastener to the sleeper or track bed; And the spring clip fastening system used for fastening rails; The air spring isolator has an adjustable air pressure sealed air cavity inside, which is connected to a valve on the air spring isolator so as to adjust the elastic characteristics of the air spring isolator by adjusting the air pressure in the air cavity.

[0011] In some examples of this application, the air spring vibration isolator further includes an upper support plate and a lower support plate, with a rubber connecting plate disposed between the upper support plate and the lower support plate, and the valve disposed on the rubber connecting plate.

[0012] In some examples of this application, the rubber connecting plate includes a rubber body with a reinforcing layer embedded on the inner side of the rubber body.

[0013] In some examples of this application, the reinforcing layer is a multilayer polyester fabric or nylon canvas arranged circumferentially along the air cavity and bonded to the rubber body by vulcanization.

[0014] In some examples of this application, the valve is located on the upper side of the rubber body.

[0015] In some examples of this application, a first groove is provided on the lower iron pad, and the air spring vibration isolator is placed in the first groove.

[0016] In some examples of this application, a limiting pad is provided between the upper iron pad and the lower iron pad.

[0017] In some examples of this application, the limiting pad is a solid rubber limiting pad, the lower surface of which is fixed to the upper surface of the lower iron pad, and a vertical gap of a preset height is formed between the upper surface of the limiting pad and the lower surface of the upper iron pad.

[0018] In some examples of this application, the air spring vibration damping fastener further includes a condition monitoring mechanism. The condition monitoring mechanism includes a mating groove disposed on the upper surface of the limiting pad and communicating with the vertical gap, and an alarm block movably disposed within the mating groove. Under normal operating conditions, the alarm block extends at least partially out of the mating groove and is located in the vertical gap. When the air spring vibration isolator malfunctions and causes the upper iron pad to move downward, the upper iron pad can press against the alarm block and cause it to fall into the mating groove, so as to indicate the usage status of the vibration damping fastener through the change in the position of the alarm block.

[0019] In some examples of this application, the limiting pads are provided in multiple ways, and the multiple limiting pads are arranged symmetrically on opposite sides of the air spring vibration isolator, and the vertical gap is 5-15 mm.

[0020] In some examples of this application, a rail pad and an insulating buffer pad are also included, wherein the rail pad is disposed between the rail and the upper rail pad, and the insulating buffer pad is disposed between the lower rail pad and the sleeper or track bed.

[0021] Compared with the prior art, the air spring vibration damping fastener of the present invention has the following advantages: 1. Excellent vibration reduction performance: Utilizing compressed air as an elastic medium, its damping characteristics are superior to pure rubber, which can more effectively absorb and isolate low- and medium-frequency vibrations and noise, resulting in a significant improvement in vibration reduction effect.

[0022] 2. Stiffness Adaptive Load: Air springs possess a unique nonlinear characteristic where stiffness increases with increasing load. When the train load increases, the internal pressure of the air cavity rises, and the spring stiffness automatically increases, thus providing a soft damping effect under no-load conditions and sufficient support stiffness under heavy load conditions, perfectly adapting to changing operating conditions.

[0023] 3. Stiffness can be actively adjusted: The air cavity can be inflated or deflated through the inflation valve, so that the static stiffness and vibration reduction characteristics of the entire fastener system can be actively and conveniently adjusted according to actual needs (such as changes in line conditions or adjustments to vibration reduction targets) after installation or during operation, which is extremely flexible.

[0024] 4. Safety Redundancy Design: The limiting pad assembly is connected in parallel with the air spring vibration isolator. Under normal circumstances, the air spring independently bears the load and reduces vibration. In emergency situations such as extreme overload or air spring failure, the upper rail pad sinks and contacts the solid rubber limiting pad, forming a second line of defense for load bearing and buffering, preventing excessive deterioration of track geometry and ensuring train operation safety.

[0025] 5. Long service life: The rubber body structure with internal reinforcement layer is sturdy, and the rubber of the air spring mainly bears the surface pressure during operation. The stress state is better than that of solid rubber under shear or compression, resulting in better fatigue resistance and durability.

[0026] 6. Intuitive and reliable status monitoring: By setting a matching groove and configuring an alarm block on the limit pad, the height change of the air spring vibration isolator can be directly converted into the position change of the alarm block. The working status that was originally located inside the fastener and difficult to observe is made visible as an identifiable structural status. Inspection personnel can judge whether the fastener is abnormal by visual inspection or simple detection without disassembly or with the help of complex equipment, which significantly improves inspection efficiency and reduces the risk of misjudgment.

[0027] 7. Simple and reliable monitoring structure: The condition monitoring mechanism uses the relative displacement between the upper iron pad and the limit pad to achieve pure mechanical linkage. It does not rely on electrical components, sensors or external power. The structure is simple, the failure probability is low, and it can adapt to complex track environments such as vibration, dust and temperature changes for a long time. It has low maintenance requirements and high reliability.

[0028] 8. Does not affect the original vibration reduction performance: The warning block does not participate in the load under normal working conditions. Its action is only triggered when the air spring vibration isolator is abnormal. It does not change the original force path and vibration reduction mechanism of the fastener, does not interfere with the compression and rebound process of the air spring, and does not weaken the vibration reduction performance and safety limit function of the fastener.

[0029] 9. Compact structure and easy to implement: The condition monitoring mechanism can achieve functional expansion by mainly improving the local structure of the limit pad. It does not require major adjustments to the main structure of the fastener. The processing and assembly process is simple, the increase in manufacturing cost is limited, and it is easy to promote and apply in existing fastener structures.

[0030] 10. Improved safety and maintainability: The change in the position of the warning block can promptly reflect the abnormal state of the air spring vibration isolator, enabling potential faults to be detected and dealt with in the early stages. This avoids long-term operation with defects due to air spring vibration isolator failure, thereby improving the overall operational safety, maintainability, and engineering application value of the vibration damping fastener. Attached Figure Description

[0031] Figure 1 This is a side view of the air spring vibration damping fastener described in an embodiment of the present invention; Figure 2 This is an exploded structural diagram of the air spring vibration damping fastener described in an embodiment of the present invention; Figure 3 This is a schematic diagram of the main assembly of the air spring vibration damping fastener described in an embodiment of the present invention; Figure 4 This is a side view of the air spring vibration isolator described in an embodiment of the present invention; Figure 5 This is a cross-sectional view of the air spring vibration isolator described in an embodiment of the present invention; Figure 6 This is a partial structural schematic diagram of the rubber connecting plate described in an embodiment of the present invention; Figure 7 This is a side view of the limiting pad described in an embodiment of the present invention; Figure 8 This is a partial structural diagram of the vertical gap between the limiting pad and the upper iron pad described in an embodiment of the present invention; Figure 9 This is a side view of the air spring vibration damping fastener described in an embodiment of the present invention; Figure 10 This is a schematic diagram of the assembly structure of the warning block set on the limiting pad according to an embodiment of the present invention; Figure 11 This is a cross-sectional structural diagram of a warning block provided on a limiting pad as described in an embodiment of the present invention; Figure 12 This is a schematic diagram of the assembly structure of the warning block provided on the limiting pad in the third embodiment of the present invention; Figure 13 yes Figure 12 A schematic diagram of the structure of the warning block shown in the figure; Figure 14 yes Figure 12 Schematic diagram of the explosion structure of the limiting pad and warning block described above; Figure 15 It is a setting Figure 12 An exploded structural diagram of an air spring damping fastener with a warning block limiting pad. The markings in the diagram are as follows: 1. Rail; 2. Rail pad; 3. Upper rail pad; 4. Limiting pad; 401. Fitting groove; 4011. Limiting part; 4012. First receiving groove; 4013. Second receiving groove; 5. Air spring vibration isolator; 501. Upper bearing plate; 502. Lower bearing plate; 503. Rubber connecting plate; 5031. Rubber body; 5032. Reinforcing layer; 504. Air cavity; 505. Valve; 6. Locking cover plate; 7. Base plate connecting sleeve; 8. Lower rail pad; 801. First groove; 802. First through hole; 9. Vertical gap; 10. Anchoring system; 11. Elastic clip clamping system; 12. Insulating buffer pad; 13. Warning block; 131. Stop part; 132. Guide part; 133. Indicator part. Detailed Implementation

[0032] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0033] It should be noted that all directional and positional terms used in this invention, such as "up," "down," "left," "right," "front," "back," "vertical," "horizontal," "inner," "outer," "top," "lower," "lateral," "longitudinal," and "center," are only used to explain the relative positional relationships and connections between components in a specific state (as shown in the accompanying drawings). They are merely for the convenience of describing the invention and do not require the invention to be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on the invention. Furthermore, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated.

[0034] In the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" 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 mechanical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0035] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Example 1

[0036] like Figures 1-9 As shown, this application discloses an air spring vibration damping fastener, comprising: Upper iron pad 3 is used to bear and transfer the wheel-rail load from the rail 1; Air spring vibration isolator 5 is disposed below the upper iron pad 3 to provide elastic vibration isolation support; The lower iron pad 8 is set at the lower part of the air spring vibration isolator 5 and is used to bear and distribute the load; Anchoring system 10 is used to fix the entire fastener, including the upper iron pad 3, the air spring vibration isolator 5 and the lower iron pad 8, to the sleeper or track bed. The elastic clip clamping system 11 is installed on the upper iron pad 3 and is used to elastically clamp and fix the rail 1. The air spring isolator 5 has a sealed air cavity 504 inside and a valve 505 communicating with the air cavity 504. The elastic characteristics of the air spring isolator 5 can be adjusted by adjusting the air pressure inside the air cavity 504, thereby forming an adjustable elastic support structure with the air spring as the core in the rail load transmission path.

[0037] The air spring vibration damping fastener disclosed in this application highly integrates rail bearing, elastic vibration isolation, and fixed anchoring functions, enabling the rail wheel-rail load to be transmitted sequentially and effectively controlled along a clear and continuous path. The upper rail pad 3, as a key component directly bearing the rail load, not only ensures the stable positioning of the rail in the longitudinal and transverse directions but also initially disperses the wheel-rail load through its structural stiffness and contact area, thereby avoiding the adverse effects of localized stress concentration on the lower elastic system. The air spring vibration isolator 5 is arranged between the upper rail pad 3 and the lower rail pad 8, placing it at the core of the entire fastener system's stress distribution. Through the compressibility of its internal sealed air cavity 504, it bears the main elastic deformation during load transmission. Compared to traditional structures using solid rubber as the elastic medium, this structure, which performs both shape and energy buffering tasks, no longer relies solely on the inherent elasticity of the material itself during load-bearing. Instead, it participates in the stress response through changes in the gas state, broadening the possibilities for elastic adjustment at the structural level. During train operation, when a load is applied to the air spring isolator 5, its internal sealed air cavity 504 is compressed, and the air pressure inside the cavity increases accordingly. Utilizing the compressibility of air, an elastic reaction force is generated, thereby buffering and attenuating the wheel-rail load. As the magnitude of the train load changes, the air pressure state within the air cavity 504 changes accordingly, causing the air spring isolator 5 to exhibit different elastic response characteristics under different load conditions. Under light load or no-load conditions… The air cavity 504 has a relatively low degree of compression, resulting in a softer support state for the overall elastic system, which is beneficial for vibration absorption and isolation. Under heavy load conditions, the air cavity 504 is further compressed, significantly increasing the internal air pressure, thereby improving the support capacity of the elastic system and ensuring the stability of the rail and track structure. Simultaneously, the air cavity 504 can be actively inflated or deflated via the air valve 505. The initial state of the air spring can be preset during installation, and the air pressure can be adjusted according to changes in track conditions or vibration reduction requirements during operation, thus altering the response characteristics of the elastic system. The lower iron pad 8 provides a stable and reliable installation and load-bearing foundation for the air spring vibration isolator 5, its function not only being to support and restrict the spatial position of the air spring vibration isolator 5. Furthermore, in conjunction with the anchoring system 10, the load from the superstructure is evenly transferred to the sleepers or track bed, thereby ensuring the stability of the overall track structure. The anchoring system 10, through the overall locking of each component, ensures that the fasteners maintain structural integrity in a long-term vibration environment, preventing loosening or displacement due to repeated loads. The elastic clip fastening system 11 is directly integrated into the upper rail pad 3, achieving reliable fastening of the rail 1, ensuring that the rail 1 does not undergo adverse displacement while maintaining necessary elastic constraints. Overall, a composite track vibration damping fastener structure is formed, with an air spring as the elastic core, metal components as the force transmission skeleton, and the anchoring system 10 as the stable foundation. Due to the characteristics of the air spring, the greater the load, the higher the internal pressure, and the greater the stiffness.This achieves adaptive behavior, providing a solid foundation for higher levels of vibration control and load adaptability at the structural level.

[0038] Through the above-described configuration, the air spring vibration damping fastener described in this application effectively reduces the transmission intensity of wheel-rail vibration to the substructure and surrounding environment while ensuring stable rail fixation and reliable track geometry. Its core advantage lies in the fact that the elastic system no longer relies on solid materials with fixed stiffness, but instead participates in load-bearing and vibration damping through pressure changes in the air cavity. This allows the fastener to maintain a reasonable elastic matching relationship under different load conditions, thus avoiding the problem of traditional fasteners being too stiff under light loads and too soft under heavy loads. Simultaneously, the air pressure adjustment achieved through valve 505 allows the fastener to retain a certain performance adjustability after installation, adapting to changes in different line conditions and operational needs, thus contributing to improved flexibility and sustainability of line vibration damping solutions. Furthermore, from a system perspective, this structure, through the coordinated operation of the upper rail pad 3, air spring vibration isolator 5, lower rail pad 8, and anchoring system 10, achieves a comprehensive improvement in vibration damping performance, load adaptability, and structural safety without significantly increasing structural complexity, demonstrating good engineering application value.

[0039] As a preferred example of this application, the air spring vibration isolator 5 further includes an upper bearing plate 501 and a lower bearing plate 502, with a rubber connecting plate 503 disposed between the upper bearing plate 501 and the lower bearing plate 502, and the valve 505 disposed on the rubber connecting plate 503. This application designs the air spring vibration isolator 5 as a combined structure comprising an upper bearing plate 501, a lower bearing plate 502, and a rubber connecting plate 503. The two rubber connecting plates 503, together with the upper bearing plate 501 and the lower bearing plate 502, form a sealed air cavity 504. The upper bearing plate 501 and the lower bearing plate 502, as rigid boundary members, form stable and reliable mounting interfaces with the upper iron pad 3 and the lower iron pad 8, respectively, effectively avoiding the performance degradation problem caused by the flexible components bearing concentrated loads alone. The rubber connecting plate 503 located between the upper bearing plate 501 and the lower bearing plate 502 utilizes its flexibility and tightness... The sealing characteristics form a variable-volume air cavity between the two, enabling the air spring isolator 5 to maintain overall structural stability while possessing the necessary elastic deformation capacity, making its working state more reasonable. The valve 505 is directly set on the rubber connecting plate 503, making the air pressure regulation of the air cavity 504 more direct and efficient, reducing potential leakage points and improving the convenience of on-site operation. This allows the fastener to still have high performance adjustment flexibility after installation. This structural arrangement not only improves the sealing stability of the air cavity 504, but also makes the inflation and deflation operations more intuitive and convenient, thus optimizing the structural rationality and user-friendliness of the air spring isolator 5 as a whole.

[0040] As a preferred example of this application, the rubber connecting plate 503 includes a rubber body 5031, with a reinforcing layer 5032 embedded inside the rubber body 5031. In some examples of this application, the reinforcing layer 5032 is a multi-layer polyester fabric or nylon canvas, arranged circumferentially along the air cavity 504, and fixed inside the rubber body 5031 by vulcanization bonding, thereby improving its structural strength and durability while maintaining the overall elasticity and sealing performance of the rubber connecting plate 503.

[0041] Through the above settings, the structural strength and fatigue resistance of the rubber connecting plate 503 are improved without sacrificing the original elasticity and sealing performance of the rubber, enabling it to reliably cope with the long-term repeated compression and tensile loads during train operation. The reinforcing layer 5032 effectively disperses the stress distribution inside the rubber body and reduces local stress concentration. At the same time, this internal reinforcement structure helps to maintain the controllability of the shape and volume changes of the air cavity 504, which is beneficial to slow down material aging and performance degradation, thereby extending the service life of the fastener and reducing the frequency of maintenance and replacement.

[0042] As a preferred example of this application, the valve 505 is positioned above the rubber body 5031. This arrangement avoids the main stress area of ​​the air spring isolator 5, preventing the valve 505 from being directly squeezed or impacted during vertical loads and repeated vibrations. This improves the reliability of the valve 505 and its connection to the rubber body from a structural safety perspective. Furthermore, this arrangement fully considers the spatial conditions of the track fasteners in actual installation, exposing the valve interface to the outside or top of the operable area, preventing it from being obstructed by the upper iron pad 3, spring clips, or other adjacent components. Maintenance personnel can complete air pressure testing and adjustment operations without disassembling the fastener body or adjusting other structures during installation, commissioning, or routine maintenance, thereby improving on-site operational convenience.

[0043] As a preferred example of this application, a first groove 801 is provided on the lower iron pad 8, and the air spring vibration isolator 5 is placed in the first groove 801. In some examples of this application, the outer dimensions of the lower bearing plate 502 of the air spring vibration isolator 5 match the first groove 801, and it is fixed in the first groove 801 by interference fit, bonding or bolt connection.

[0044] This application transforms the traditional planar placement of the air spring vibration isolator 5 into an embedded installation structure by setting a first groove 801 on the lower iron pad 8 that matches the lower bearing plate 502 of the air spring vibration isolator 5. This provides a clear and stable installation boundary for the air spring vibration isolator 5, allowing it to be accurately positioned during installation and avoiding misalignment or uneven stress caused by installation errors. At the same time, the sidewall of the first groove 801 forms a circumferential constraint on the air spring vibration isolator 5, effectively suppressing its lateral displacement, swaying, or rotational tendency under the vibration of train operation, thus ensuring that the vibration isolator is always in the ideal working position. Through the combination of the groove and the fixing method, the air spring vibration isolator 5 and the lower iron pad 8 form a stable integrated structure, which not only improves structural stability but also creates favorable conditions for maintaining vibration isolation performance in the long term.

[0045] As a preferred example of this application, a limiting pad 4 is provided between the upper iron pad 3 and the lower iron pad 8. The limiting pad 4 and the air spring vibration isolator 5 are arranged in parallel in the vertical direction, and a vertical gap 9 of a preset height is formed between the limiting pad 4 and the upper iron pad 3. This application, by adding a limiting pad 4 between the upper iron pad 3 and the lower iron pad 8, and making it parallel to the air spring vibration isolator 5 in the vertical direction, allows the fastening system to maintain the independent operation of the air spring as the main vibration damping unit while introducing a backup limiting structure that does not participate in daily stress. This structure maintains a preset vertical gap 9 with the upper iron pad 3 under normal working conditions, without affecting the compression and rebound stroke of the air spring vibration isolator 5, thereby ensuring that the air spring can fully utilize its adjustable stiffness and efficient vibration damping advantages. The limiting pad 4 is made of an elastic material with good elasticity and buffering capacity, which can... Under extreme loads or abnormal operating conditions, it can quickly intervene and limit the excessive sinking of the upper iron pad 3 through flexible contact, avoiding rigid collisions between metal components and reducing the probability of damage to the upper iron pad 3, lower iron pad 8 and related connecting parts. At the same time, the parallel structure makes the two elastic elements functionally independent, avoiding the problem of mutual interference in performance in traditional series structures. In the long-term standby state, the limiting pad 4 does not participate in cyclic force, which helps to extend its service life. Overall, it improves the adaptability of the fastening system to uncertain loads and sudden operating conditions, and enhances the safety, reliability and long-term service stability of the track structure.

[0046] As a preferred example of this application, the limiting pad 4 is a solid rubber limiting pad, the lower surface of which is fixed to the upper surface of the lower iron pad 8, and a vertical gap 9 of a preset height is formed between the upper surface of the limiting pad 4 and the lower surface of the upper iron pad 3. Through the above setting, the solid rubber material itself has good elastic recovery ability and energy absorption characteristics, and can still maintain stable performance even when it does not participate in the load for a long time. Combined with the reserved vertical gap 9 between its upper surface and the lower surface of the upper iron pad 3, the limiting pad 4 does not enter the load-bearing state at all under normal operating conditions, thereby avoiding any interference with the normal compression stroke and vibration reduction characteristics of the air spring vibration isolator 5. This makes the limiting pad form a passive protection unit with stable position but delayed function in the overall fastener system, which will not produce relative displacement due to vibration, nor will it age prematurely due to long-term pressure. In the example of this application, the solid rubber limiting pad refers to the limiting pad 4 being made entirely of solid rubber material, and the limiting pad 4 is provided with a clearance structure at the positions of other connecting parts such as the anchoring system 10 and the elastic clip clamping system 11.

[0047] As a preferred example of this application, multiple limiting pads 4 are provided, and the multiple limiting pads 4 are symmetrically arranged on opposite sides of the air spring isolator 5. The height of the vertical gap 9 is determined according to the maximum allowable compressive displacement of the air spring isolator 5 under the design load conditions, preferably 5-15 mm. By setting multiple limiting pads 4 (e.g., two or four) and symmetrically distributing them about the air spring isolator 5, this application makes the limiting structure form a balanced and reasonable protective layout in space. When the limiting function is triggered, the upper iron pad 3 can simultaneously obtain symmetrical support from both sides of the air spring isolator 5, thereby effectively avoiding tilting, off-center loading, or additional torque problems caused by unilateral force, making the track stress state more stable and reliable. At the same time, multiple limiting pads 4 share the impact load under extreme working conditions, reduce the compressive stress borne by a single limiting pad 4, improve the overall structure's durability and safety redundancy level, and reduce the vertical gap 9. The height of the straight gap is clearly limited to the range of 5-15 mm, which gives the limiting system a clear and controllable triggering condition. This gap range fully covers the entire normal compression stroke of the air spring isolator 5 under the design load, ensuring that the limiting pad does not participate in the stress and does not affect the vibration reduction performance of the air spring under normal operating conditions. At the same time, it can quickly intervene when the air spring isolator 5 reaches or exceeds its maximum allowable compression displacement, thus forming a clear boundary between performance release and safety control. This makes the fastening system have good versatility and adaptability under different line and load conditions, and can achieve a stable and reliable safety protection effect without complicated adjustments.

[0048] As a preferred example of this application, the elastic clip fastening system 11 includes an elastic clip, a gauge block, and fastening components. The elastic clip is fixed to the upper surface of the upper rail pad 3 by the fastening components and applies a continuous fastening force to the rail 1. The gauge block is disposed between the rail 1 and the upper rail pad 3 and is used to laterally limit the rail to prevent longitudinal movement and lateral displacement of the rail during train operation. The above design is a conventional technology for track vibration damping fasteners and will not be described in detail here.

[0049] In the example of this application, a first through hole 802 is provided on the lower iron pad 8, and correspondingly, an avoidance hole is provided on the limiting pad 4 corresponding to the first through hole 802, which is used to avoid the fastening components in the spring clip clamping system 11.

[0050] As a preferred example of this application, the anchoring system 10 includes anchor bolts, embedded sleeves, a base plate connecting sleeve 7, a locking cover plate 6, and flat washers or spring washers. The embedded sleeves are pre-embedded in the sleepers or track bed. The base plate connecting sleeve 7 is fitted onto the mounting boss of the lower rail pad 8. The locking cover plate 6 is located at the upper end of the base plate connecting sleeve 7. The anchor bolts pass sequentially through the corresponding through holes on the locking cover plate 6, the upper rail pad 3, and the lower rail pad 8, and are screwed into the embedded sleeves. The flat washers or spring washers are placed between the anchor bolts and the upper rail pad 3, thereby reliably anchoring the entire air spring vibration damping fastener to the sleepers or track bed. The above design is a conventional technology for track vibration damping fasteners and will not be described in detail here.

[0051] As a preferred example of this application, the air spring vibration damping fastener further includes a rail pad 2 and an insulating buffer pad 12. The rail pad 2 is disposed between the rail 1 and the upper rail pad 3 to form an elastic buffer interface between the rail 1 and the upper rail pad 3. The insulating buffer pad 12 is disposed between the lower rail pad 8 and the sleeper or track bed to form a transition layer with buffering and insulation functions between the lower rail pad 8 and the sleeper or track bed, thereby constructing a multi-layer buffering and isolation structure in the air spring vibration damping fastener. This application introduces a rail pad 2 and an insulating buffer pad 12 to create flexible transition interfaces between the rail 1 and the upper rail pad 3, as well as between the lower rail pad 8 and the sleeper or track bed. This achieves a step-by-step vibration attenuation effect at the structural level. The rail pad 2 effectively reduces the intensity of rail vibration directly acting on the upper rail pad 3, making the contact between the rail 1 and the fasteners smoother, thereby reducing wear and extending the service life of key components. The insulating buffer pad 12 weakens the transmission of vibration to the sleeper or track bed while significantly improving the electrical isolation performance of the fastener system and reducing the risk of stray current corrosion to the track structure and surrounding metal facilities. In addition, the combined effect of both allows vibration to gradually attenuate at multiple interfaces, avoiding excessive energy load on a single component and ensuring that the air spring vibration isolator is always in a more reasonable working state. This improves the overall smoothness and environmental friendliness of the track structure operation while reducing maintenance frequency.

[0052] The air spring vibration damping fastener disclosed in this application achieves systematic optimization of the load-bearing path, elastic source, and performance adjustment method at the overall structural level by replacing the traditional solid rubber pad with an air spring vibration isolator 5 as the core elastic support unit. Its technical concept is no longer limited to relying on the inherent elasticity of materials for vibration damping, but introduces compressible air as the elastic medium participating in load bearing and vibration damping. This allows the fastener system to form a more reasonable elastic response relationship under different load conditions, maintaining soft vibration isolation under light loads and providing sufficient support under heavy loads. This effectively alleviates the problem of traditional fasteners struggling to balance vibration damping performance and load-bearing capacity under changing working conditions. Furthermore, by setting a limiting pad 4 in parallel with the air spring vibration isolator 5 and reserving a reasonable vertical gap 9, it achieves this without interfering with the air spring vibration isolator 5. Under the premise that the gas spring is working normally, a reliable safety redundancy structure is constructed so that the fasteners can still limit excessive track settlement under abnormal conditions such as extreme overload (such as heavy construction machinery accidentally entering) or air spring failure (accidental damage), ensuring track geometry and operational safety. In addition, through the coordinated arrangement of the upper iron pad 3, air spring vibration isolator 5, lower iron pad 8 and anchoring system 10, the wheel-rail load forms a clear, continuous and controlled transmission path in the structure. Combined with the multi-layer buffer and isolation structure formed by the rail pad 2 and the insulating buffer pad 12, the vibration is gradually attenuated during transmission. At the same time, the electrical isolation and foundation protection requirements are taken into account. Without significantly increasing the system complexity, the comprehensive improvement of vibration reduction performance, load adaptability, electrical safety and structural durability is achieved. Example 2

[0053] like Figures 1-15 As shown, this embodiment adds a condition monitoring mechanism to the air spring vibration damping fastener described in Embodiment 1 above, including: The mating groove 401 is provided on the upper surface of the limiting pad 4 and communicates with the vertical gap 9; Warning block 13 is movably disposed within the mating groove 401; Under normal operating conditions, the warning block 13 extends at least partially out of the mating groove 401 and is located in the vertical gap 9; When the air spring vibration isolator 5 is in an abnormal state, the upper iron pad 3 moves down and presses against the warning block 13, causing it to fall into the mating groove 401, so as to indicate the usage status of the vibration damping fastener through the position change of the warning block 13.

[0054] This application forms a status monitoring mechanism by setting a mating groove 401 on the limiting pad 4 that communicates with the vertical gap 9, combined with the warning block 13. This mechanism uses the mating groove 401 to provide a stable installation space for the warning block 13, and the warning block 13 is naturally located in the stress change path of the structure. The connection relationship ensures that the height position of the warning block 13 can truly reflect the change in the gap between the upper iron pad 3 and the limiting pad 4, so that the status monitoring does not rely on an additional sensing structure but is directly related to the displacement state of the internal components of the fastener body, thereby realizing the status recognition function without changing the main structure and stress mode of the fastener. When the fastener is in normal working condition, the air spring isolator 5 maintains the designed support height, and a stable vertical gap 9 is formed between the upper iron pad 3 and the limiting pad 4. The warning block 13 stably extends partly out of the mating groove 401 and is located in the vertical gap 9 by its own structure. At this time, the warning block 13 does not contact the upper iron pad 9 and does not participate in the load-bearing. The vibration reduction and load-bearing process of the entire fastener system is still completed by the air spring isolator 5 and related structures. When the support height of the air spring isolator 5 decreases due to air leakage, damage or other reasons, the upper iron pad 3 gradually moves downward under the action of wheel-rail load. As the displacement increases, the lower surface of the upper iron pad 3 contacts the warning block 13 and applies pressure to it. Under continuous load, the warning block 13 overcomes the mating resistance between itself and the mating groove 401 and moves downward in the predetermined direction, accompanied by light pressure if necessary. The device undergoes slight deformation and eventually fully or almost completely enters the mating groove 401. At this point, the top height of the warning block 13 is significantly lower than the normal state. This change from convex to concave has a clear visual difference, allowing inspectors to quickly and accurately determine whether the fastener is abnormal. If necessary, it can be used in conjunction with a mechanical probe or height recognition device to further improve the accuracy of monitoring. At the same time, this action is directly driven by the height change of the air spring vibration isolator 5, without relying on external power or control system. It is a purely mechanical linkage process. Its action depends on the displacement relationship of the fastener body and does not require power supply, wiring or signal processing devices. Therefore, it has the characteristics of simple structure, high reliability and low maintenance requirements. It can adapt to long-term vibration, dust and temperature changes in the track environment, thus maintaining a stable and reliable indication effect under complex vibration conditions.

[0055] This application, by setting up the aforementioned condition monitoring mechanism, enables the working status of the air spring vibration isolator 5, a key component that was originally located inside and not easily observed directly, to be intuitively reflected through the positional changes of the warning block 13. This achieves the externalization of the health status of the vibration damping fastener, improves inspection efficiency, and reduces the risk of misjudgment. The overall structure is compact, mainly relying on the local structure of the limiting pad 4 for improvement. It does not change the main installation method and force path of the fastener, and has no adverse impact on the original vibration damping performance and safety limiting function. It adds fault warning and condition self-inspection capabilities to the fastener, enabling the product to maintain structural reliability while having higher maintenance convenience and engineering application value.

[0056] As a preferred example of this application, the warning block 13 is an aluminum pad or an elastic pad, which allows it to be positioned above the opening of the mating groove 401 and at least partially extend into the mating groove 401 when not under pressure, and to displace and fall into the mating groove 401 when subjected to pressure from the upper iron pad 3. This application uses materials with moderate strength and a certain degree of deformation capacity, such as aluminum pads or elastic pads, to prepare the warning block 13, giving it both stable support and smooth response in terms of structural performance. Under normal operating conditions, the material itself has moderate strength and rigidity, enabling it to be stably positioned at the opening of the mating groove 401. It maintains a stable posture even under the effects of periodic vibrations and environmental disturbances generated by train operation, preventing malfunctions or slippage, thus ensuring the reliability of the monitoring status. Under abnormal operating conditions, when the upper iron pad 3 moves downward and exerts pressure on the warning block 13, this type of material exhibits moderate deformation or displacement capacity, allowing the warning block 13 to smoothly enter the mating groove 401. Within the groove 401, the material's hardness will prevent jamming or damage to the surrounding structure, thus ensuring stable and consistent monitoring actions. Furthermore, the aluminum or elastic material is easy to process, forming the required shape through conventional stamping or molding processes, resulting in low manufacturing costs, good dimensional consistency, and easy application in fasteners of different specifications. The material itself is lightweight, not increasing the structural burden of the fastener system, nor affecting the compression and rebound process of the air spring isolator 5 or the safety support function of the limiting pad 4. This allows the monitoring mechanism to expand its functions without altering the original structural force path, thereby improving the overall maintainability and engineering applicability of the fastener system.

[0057] As a preferred example of this application, the warning block 13 includes a stop portion 131 and a guide portion 132, and the mating groove 401 includes a limiting portion 4011 and a first receiving groove 4012. The cross-sectional area of ​​the stop portion 131 is larger than the opening area of ​​the limiting portion 4011, so that the stop portion 131 can be positioned outside the groove of the limiting portion 4011. The guide portion 132 extends into the first receiving groove 4012 and guides it to limit the position of the warning block 13 and guide the warning block 13 to move into the mating groove 401 when pressed. This application utilizes the dimensional fit between the stop portion 131 and the limiting portion 4011 to ensure the warning block 13 has high stability under normal operating conditions. This effectively resists vibrations and environmental disturbances generated by train operation, preventing false alarms and improving the reliability of condition monitoring results. Simultaneously, the fit between the guide portion 132 and the first receiving groove 4012 allows the warning block 13 to move along a predetermined path under pressure, significantly reducing the risk of jamming or incomplete action, thereby improving the success rate and consistency of monitoring actions. Furthermore, the functional separation of the stop portion 131 and the guide portion 132 allows the warning block 13 to both provide stable support and achieve smooth guidance, ensuring reliability while maintaining low processing difficulty and assembly complexity, which is beneficial for mass production and engineering application. In some examples of this application, the guide portion 132 is arranged with a gradually increasing cross-sectional area from the side closer to the stop portion 131 to the side farther away from the stop portion 131, ensuring that the warning block 13 can reliably fall into the fitting groove 401 under pressure. Furthermore, the distance between the upper surface of the stop part 131 and the lower surface of the upper iron pad 3 is sufficient to satisfy the compression and rebound motion trajectory of the air spring vibration isolator 5 under normal pressure conditions, so that the upper iron pad 3 does not contact the stop part 131 under normal working conditions, and contacts the stop part 131 when the air spring vibration isolator 5 abnormally causes the compression to exceed the normal motion range to trigger the alarm block action.

[0058] As a preferred example of this application, the warning block 13 is provided with a prompting part 133, and the limiting pad 4 is provided with a second receiving groove 4013 that cooperates with the prompting part 133. One end of the second receiving groove 4013 is connected to the limiting part 4011, and the other end extends to the edge of the limiting pad 4, so that the prompting part 133 can enter or exit the second receiving groove 4013 when the warning block 13 is displaced, thereby forming an identifiable status indication through the positional change of the prompting part 133 relative to the limiting pad 4. This application provides an integrally formed indicator section 133 on one side of the stop section 131, which enhances the status indication features of the warning block 13 while maintaining its original structural function. This allows inspection personnel to determine the working status without disassembling the structure, improving the efficiency and intuitiveness of on-site inspections. At the same time, a second receiving groove 4013 that cooperates with the indicator section 133 is provided on the limiting pad 4, so that the indicator section 133 has a clear movement path and receiving space when it is displaced, avoiding interference between the indicator section 133 and the surrounding structure during movement, thereby ensuring smooth and stable operation. In some examples of this application, one end of the second receiving groove 4013 is connected to the limiting part 4011, and the other end extends to the edge of the limiting pad 4. The cross-sectional area of ​​the prompting part 133 is smaller than the cross-sectional area of ​​the second receiving groove 4013, so that the prompting part 133 can fall into the second receiving groove 4013 as the warning block 13 moves down. This allows the inspection personnel to determine whether the device is in normal condition by observing the position of the prompting part 133 at the edge of the limiting pad 4. There is no need to add electrical components or complex sensing devices. It can be compatible with multiple identification methods such as manual observation, mechanical probe detection or electronic identification device detection while ensuring a simple structure. The working status of the air spring vibration isolator 5 can be determined by detecting the position of the prompting part 133, so that the system has good adaptability and scalability.

[0059] In some examples of this application, the length of the prompting part 133 is adapted to the length of the second receiving groove 4013, so that the prompting part 133 can partially extend or be completely retracted into the second receiving groove 4013 after falling into it, so as to facilitate visual identification by personnel or detection by identification devices. In some embodiments, the length of the prompting part 133 may be slightly greater than, equal to or slightly less than the length of the second receiving groove 4013 to meet the needs of different identification methods.

[0060] This application, by setting a mating groove 401 communicating with the vertical gap 9 on a partial structure of the limiting pad 4 and configuring an alarm block 13 that can move when the upper iron pad 4 moves too much, allows the working status of the air spring vibration isolator 5, a key component originally located inside the fastener and difficult to observe directly, to be intuitively reflected by the positional change of the alarm block 13. This achieves externalization of the operating status of the vibration damping fastener, improves inspection efficiency, and reduces the risk of misjudgment. Simultaneously, through the dimensional matching relationship between the stop part 131 and the limiting part 4011, the alarm block 13 remains stable and without triggering under normal vibration conditions, while reliably triggering when the support capacity of the air spring vibration isolator 5 decreases, thus ensuring the accuracy and consistency of monitoring results. Through the cooperation of the guide part 132 and the first receiving groove 4012, the alarm block 13 moves along a predetermined path when compressed, reducing jamming and incomplete movement, improving the reliability and repeatability of the mechanism. Through reasonable design... The distance between the stop part 131 and the upper iron pad 3 ensures that the condition monitoring mechanism only participates in the force when the air spring vibration isolator 5 is abnormally displaced. This avoids interference with the normal vibration reduction process and ensures that the alarm triggering time is consistent with the actual abnormal state. At the same time, by setting the prompt part 133 and the second receiving groove 4013 that cooperates with it, the state change can form obvious identifiable features on the edge of the limiting pad 4. This allows for compatibility with multiple identification methods such as manual visual inspection, mechanical probe detection, and electronic identification device detection. Reliable monitoring can be achieved without adding complex sensors or electrical systems. The overall structure is mainly based on the local improvement of the limiting pad 4. It does not change the main structure of the fastener or the main force path, and has no adverse effect on the original vibration reduction performance and safety limiting function. Thus, while maintaining a simple structure, high reliability, and low manufacturing cost, the vibration damping fastener has fault warning and condition self-inspection capabilities, which significantly improves the engineering application value and maintenance convenience of the product.

[0061] This invention is applicable not only to newly built subway lines, but also to the vibration reduction and upgrading of existing lines, and has broad engineering application prospects.

[0062] The embodiments of this application have been described above with reference to the accompanying drawings. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. This application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. An air spring vibration damping fastener, characterized in that, include: The upper iron pad (3), the air spring vibration isolator (5), and the lower iron pad (8) are arranged sequentially from top to bottom. An anchoring system (10) used to secure the entire fastener to the sleeper or track bed. And a spring clip fastening system (11) for fastening the rail (1). The air spring isolator (5) has an adjustable air pressure sealed air cavity (504) inside. The air cavity (504) is connected to a valve (505) provided on the air spring isolator (5) so as to adjust the elastic characteristics of the air spring isolator (5) by adjusting the air pressure in the air cavity (504).

2. The air spring vibration damping fastener according to claim 1, characterized in that, The air spring vibration isolator (5) further includes an upper support plate (501) and a lower support plate (502), and a rubber connecting plate (503) is provided between the upper support plate (501) and the lower support plate (502), and the valve (505) is provided on the rubber connecting plate (503).

3. The air spring vibration damping fastener according to claim 2, characterized in that, The rubber connecting plate (503) includes a rubber body (5031) and a reinforcing layer (5032) is embedded on the inner side of the rubber body (5031).

4. The air spring vibration damping fastener according to claim 3, characterized in that, The valve (505) is located on the upper side of the rubber body (5031).

5. An air spring vibration damping fastener according to any one of claims 1 to 4, characterized in that, A first groove (801) is provided on the lower iron pad (8), and the air spring vibration isolator (5) is placed in the first groove (801).

6. The air spring vibration damping fastener according to claim 5, characterized in that, A limiting pad (4) is provided between the upper iron pad (3) and the lower iron pad (8).

7. An air spring vibration damping fastener according to claim 6, characterized in that, The limiting pad (4) is a solid rubber limiting pad, the lower surface of which is fixed to the upper surface of the lower iron pad (8), and a vertical gap (9) of a preset height is formed between the upper surface of which and the lower surface of the upper iron pad (3).

8. An air spring vibration damping fastener according to claim 6 or 7, characterized in that, It also includes a status monitoring mechanism, which includes a mating groove (401) disposed on the upper surface of the limiting pad (4) and communicating with the vertical gap (9), and an alarm block (13) that can be movably disposed in the mating groove (401). Under normal working conditions, the alarm block (13) extends at least partially out of the mating groove (401) and is located in the vertical gap (9). When the air spring vibration isolator (5) is in an abnormal state, causing the upper iron pad (3) to move down, the upper iron pad (3) can press the alarm block (13) and make it fall into the mating groove (401) so as to indicate the usage status of the vibration damping fastener through the position change of the alarm block (13).

9. An air spring vibration damping fastener according to claim 8, characterized in that, The limiting pads (4) are configured in multiple ways, and the multiple limiting pads (4) are arranged symmetrically on opposite sides of the air spring vibration isolator (5). The vertical gap (9) is 5-15 mm.

10. An air spring vibration damping fastener according to claim 1, characterized in that, It also includes a rail pad (2) and an insulating buffer pad (12). The rail pad (2) is disposed between the rail (1) and the upper rail pad (3), and the insulating buffer pad (12) is disposed between the lower rail pad (8) and the sleeper or track bed.

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