Shear-type railway turnout vibration-damping fastener with adjustable stiffness and method for eliminating track corrugation

Abstract

The present invention relates to a shear-type railway turnout vibration-damping fastener with adjustable stiffness and a method for eliminating track corrugation. The fastener comprises a "top plate + coupling bottom plate" with a vulcanized rubber layer bonded therebetween, forming a double-layer "coupling pad" capable of controlling and maintaining stable stiffness in three aspects. Furthermore, to address the problem of unstable node stiffness in conventional iron turnout pads due to excessive torque or loosening of the turnout tie bolts, an adjustable cover plate is provided at the turnout tie bolt connection. The adjustable cover plate is provided with a sleeve that can extend into the pad bolt mounting hole on the side facing the pad, and bosses of varying heights are evenly distributed on the end surface of the sleeve. Correspondingly, the coupling bottom plate is also provided with a corresponding sleeve at the turnout tie bolt hole, and the upward-facing end surface of the sleeve is recessed with grooves of varying depths corresponding to the adjustable cover plate. After the adjustable cover plate is installed, the bosses and grooves ensure the overall height of the pad plate is aligned, thus resolving the problem of excessive torque on the turnout tie bolts affecting the pad plate node stiffness. Furthermore, the adjustable cover plate can be rotatably installed to achieve stable overall stiffness maintenance and multi-level adjustment of the fastener system.

Description

Technical Field

[0001] The present invention relates to a shear type railway turnout vibration reduction fastener with adjustable stiffness and a method for eliminating rail corrugation, which can effectively solve the problem of rail corrugation occurring after the application of an existing vibration reduction fastener system, and belongs to the technical field of railway tracks. Background Art

[0002] During train operation, the forces between the wheels and rails constantly change, generating vibration (primary noise). This vibration is transmitted through the track to the track fasteners and trackbed, then to the soil. Through the soil, it propagates in all directions, affecting nearby underground structures or surface buildings, generating vibrations (secondary noise). Factors affecting train vibration primarily include the train, track, tunnels, buildings, and geological conditions.

[0003] 2. During the operation of tracks or switches in the urban rail transit industry, due to the influence of multiple factors such as excessive or insufficient torque control of the pad bolts in the initial laying stage, unstable vertical and vertical stiffness of the pads, and long-wave or short-wave wear of the tracks caused by the coupling of wheel-rail contact wear, the noise and vibration of rail driving will appear to a certain extent due to the vibration generated by the wheel-rail action, thereby causing periodic long-wave or short-wave driving unevenness, as well as corresponding noise and vibration, and forming track corrugation.

[0004] To mitigate track vibration and noise during operation, existing domestic railways generally use integral vulcanized shock absorbers, which utilize the shear deformation of the vulcanized rubber ring between the rail support plate and the base to achieve elasticity. However, this fastener type can provide elasticity in three directions: vertical, horizontal, and longitudinal. When the vertical load increases, the rail support plate enters the matching base plate frame, thereby achieving better dynamic stability. However, the problem is that due to the fixed rigidity of the fastener structure, it is still impossible to eliminate the impact of track corrugation in principle. The only way to eliminate the impact of track corrugation is through regular track grinding, and it is impossible to eliminate the track corrugation caused by the coupling of wheel-rail forces by adjusting the fastener rigidity.

[0005] 3. CN207244356U, named “A dual-rigidity bonding type vibration-damping fastener”, the vibration-damping fastener includes a bonding component, elastic bars, insulating gauge blocks and anchor bolts, the bonding component includes a lower iron plate, an elastic support block and an upper iron plate, the bonding component connects the lower iron plate and the upper iron plate into one body through the bonding action of the elastic support block, the lower iron plate floats the upper iron plate through the elastic support block, so that a cavity is formed between the upper iron plate and the lower iron plate. This patent can provide a better vibration-damping effect during normal driving, and can also ensure driving safety when the load increases sharply when an overloaded vehicle is driving or encountering an emergency. Its shortcomings are: this type of structure connects the lower iron pad and the upper iron pad through the elastic support block to form an assembly, that is, after the assembly, its overall stiffness is certain, that is, the fastener structure stiffness is fixed. After a period of operation, the track's condition can be affected by external factors. For example, if the track's "parametrically excited vibration" couples with the wheel-rail interaction, this can gradually cause periodic, uneven wear at the wheel-rail interface, known as corrugation. This type of structure, due to the fixed stiffness of the fastener system, cannot adjust for track corrugation. Summary of the Invention

[0006] Design purpose: To avoid the shortcomings of the background technology, a method is designed to obtain different overall stiffness of the fastener system by adjusting the axial force of the pad bolt, so as to destroy the "wheel-rail force coupling" cycle that causes rail corrugation, and ultimately achieve a method of eradicating periodic wear by designing a shear-type railway turnout vibration-damping fastener with adjustable stiffness and eliminating rail corrugation.

[0007] Design solution: To achieve the above-mentioned design objectives. Unlike the background technology, the present invention can adjust the stiffness by adjusting the connection between the "adjustable cover plate" and the coupling base plate to different degrees of compression of the elastic cushion layer. The change in stiffness then disrupts the periodic coupling between the track's "parametrically excited vibration" and the wheel-rail force, thereby achieving the purpose of eliminating corrugation. In other words, the present invention is designed and developed to solve the problem of track corrugation caused by the application of existing vibration-damping fastener systems. By adjusting the stiffness, the "wheel-rail force coupling" cycle that causes track corrugation is disrupted, ultimately achieving the purpose of eradicating periodic wear.

[0008] In the development of urban rail transit, there is an urgent need for vibration reduction on railway lines, particularly within the turnout area, where lines pass through residential areas, hospitals, scientific research institutions, and other vibration- and noise-sensitive areas. Existing subway lines commonly employ a vulcanized rubber ring between the track plate and the base, similar to a Cologne egg structure, which achieves good vibration reduction. However, after long-term use, railway line fastening systems are susceptible to long and short rail surface wear, as well as noise and vibration, due to various factors such as wheel-rail coupling. Furthermore, during installation and maintenance of the fastening system, the installation torque of the turnout tie bolts is difficult to control, which to some extent affects the overall stiffness of the fastening system.

[0009] (1) The principle of rail corrugation: According to the theory of mechanical vibration and tribology, when the geometric unevenness of the initial wheel or rail surface reaches a certain amplitude, the alternating positive pressure between the wheel and rail will occur, triggering the excitation of the internal parameters of the wheel-rail system (including the normal pressure between the wheel and rail, the relationship between the creep force and the creep rate, the stiffness and damping under the rail, etc.), which is the so-called "parametric excitation vibration". When this "parametric excitation vibration" is coupled with the tangential wear behavior of the wheel-rail contact surface, cyclic wear may occur. Therefore, any cyclic wear between the wheel and rail can be expressed as the coupling of "parametric excitation vibration" and "tangential wear". The coupling here is not necessarily the same frequency coupling, but an internal "interaction". When this "interaction" can intensify the low-point wear more than the high-point wear in phase, cyclic wear will form and expand; otherwise, cyclic wear will not form and expand. Therefore, the corrugation of the inner rail of the curve is mainly caused by the coupling of "parametrically excited vibration" and "stick-slip self-excited vibration wear"; the corrugation of the inner side of the outer rail of the curve is mainly caused by the coupling of "parametrically excited vibration" and "wheel-rail torsional vibration wear"; the corrugation on the straight line is mainly caused by the coupling of "parametrically excited vibration" and "longitudinal traction and braking tangential wear"; the wheel's non-roundness or polygonal wear is also caused by "parametrically excited vibration" and "longitudinal traction and braking longitudinal wear alternation". It can be inferred from this that all periodic wear can be adjusted by the vibration reduction system to change the phase of the "interaction", so that the wear of the raised points is greater than the wear of the lower concave points, and the periodic wear can be eradicated eventually. Therefore, in view of the formation mechanism of corrugation and in combination with the problems existing in the existing vibration reduction fastener system, the present invention designs a structure and design method by matching an adjustable cover plate with a double-layer coupling pad to achieve the design and manufacture of vibration reduction fasteners with adjustable stiffness.

[0010] (2) Principle of maintaining the rigidity of the fastener system: In existing conventional fastener systems, a rubber pad under the plate is provided between the pad and the upper surface of the switch sleeper. The overall rigidity is achieved by the fixed rigidity value of the pad under the plate, wherein the rubber pad under the rail acts as a buffer for the contact between the rail and the pad to avoid the rigid impact affecting the service life. During the actual laying process of this structure, since the switch sleeper bolts are generally tightened on site using an electric wrench or manually, the torque coefficient is relatively discrete, resulting in a large difference in the axial tension of the bolts. To solve this problem, the present invention designs a double-layer coupling pad structure, which isolates the influence of the vulcanized rubber layer through the split connection of the adjustable cover plate and the bottom plate, so that the axial force of the switch sleeper bolt is directly transmitted to the bottom surface of the pad, thereby avoiding the overall rigidity of the fastener system from being affected by the torque of the switch sleeper bolt, and ensuring the stable maintenance of the overall rigidity.

[0011] (3) The coordination between the adjustable cover plate and the coupling base plate is provided with bosses of different heights. By adjusting the coordination between the two and tightening the bolts of the switch tie, the compression degree of the vulcanized layer of the coupling pad can be achieved, thereby achieving adjustable stiffness.

[0012] (4) Principle of eliminating track corrugation: By adjusting the stiffness and changing the "interaction" between the wheel and rail, the period and frequency of the "parametric excitation vibration" can be adjusted, thereby completely solving the periodic corrugation problem.

[0013] In terms of structural design, a double-layer "coupling pad" is formed by the "top plate + coupling bottom plate" through the vulcanized rubber layer between the two, which can control the three aspects of stiffness to be stable. At the same time, in order to address the problem that the node stiffness of the iron pads used for turnouts in the past was unstable due to excessive torque or loosening of the switch tie bolts, an adjustable cover plate is set at the switch tie bolt connection. The adjustable cover plate is provided with a sleeve that can be inserted into the pad bolt mounting hole on the side facing the pad, and the end surface of the sleeve is evenly distributed with bosses of different heights; correspondingly, the coupling bottom plate is also provided with a corresponding sleeve at the switch tie bolt hole, and the upward end surface of the sleeve is concave with grooves of different depths corresponding to the adjustable cover plate. After the adjustable cover plate is installed, the boss and the groove achieve the total height coordination of the pad installation, which solves the problem of the pad node stiffness being affected by excessive torque of the switch tie bolts. At the same time, the adjustable cover plate can be installed by rotation to achieve stable maintenance of the overall stiffness of the fastener system and multi-level adjustment.

[0014] Technical Solution 1: A shear-type railway turnout vibration-damping fastener with adjustable stiffness, including a gauge block, spring bars or other fasteners for clamping rails, flat washers, and nuts. A double-layer coupling pad is provided between the back of the railway turnout and the switch sleeper. Holes for screwing to the switch sleeper are opened on both sides of the double-layer coupling pad. The pad bolts pass through the spring washers and the center hole of the adjustable cover plate to fix the adjustable cover plate and the double-layer coupling pad to the bolt holes in the switch sleeper.

[0015] Technical Solution 2: A method for eliminating rail corrugation, which adjusts the stiffness of railway turnout vibration-damping fasteners, changes the "interaction" between the wheel and rail, and adjusts the period and frequency of the "parametric excitation vibration", thus completely solving the periodic corrugation problem. The specific methods are as follows: (1) using a shear-type coupling pad to achieve vibration reduction of the fastener system; (2) using an adjustable cover plate and a coupling base plate through the installation of a preset sleeve and its bosses and grooves to directly transmit the preload force of the turnout tie bolts to the base plate, and to achieve stable vertical stiffness maintenance of the pad by isolating the coupling elastic pad layer; (3) through the concave-convex matching structure of the sleeve on the top plate and the sleeve on the coupling base plate, the thickness and stiffness of the overall vulcanized rubber layer between the top plate and the coupling base plate are adjusted, and the lateral stiffness of the coupling pad is stable.

[0016] Compared with the background technology, the present invention has the following advantages: first, the fastener node stiffness is kept stable; second, the fastener vertical stiffness is realized, and in the fastener application process, the fastener node vertical stiffness can be quickly adjusted according to the stiffness or application requirements; third, the stiffness is controlled in three directions: on the one hand, by Figure 9 The performance adjustment of the elastic element in the A position can also be done by Figure 1The out-of-plane inclination of the M shown and the matching surfaces of its related parts are set with slopes to control the vertical, lateral and longitudinal stiffness. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the assembly of a shear-type railway turnout vibration-damping fastener system with adjustable stiffness.

[0018] Figure 2 yes Figure 1 Schematic diagram of the top view of the double-layer coupling pad.

[0019] Figure 3 yes Figure 2 Schematic diagram of the cross-sectional structure along the AA axis.

[0020] Figure 4 Schematic diagram of the cross-section of the coupling base plate.

[0021] Figure 5 yes Figure 4 Schematic diagram of the enlarged structure of the middle M part.

[0022] Figure 6 2 is a top view of the adjustable cover.

[0023] Figure 7 yes Figure 6 Schematic diagram of the cross-section structure.

[0024] Figure 8 yes Figure 7 Enlarged schematic diagram of the center boss reference surface.

[0025] Figure 9 Schematic diagram of eliminating rail top corrugation by destroying the wheel-rail coupling. DETAILED DESCRIPTION

[0026] (1) Use shear-type coupling pads to achieve vibration reduction of the fastener system;

[0027] (2) The adjustable cover plate and the coupling base plate are installed through a preset sleeve and its bosses and grooves to directly transmit the preload force of the switch tie bolts to the base plate, and the vertical stiffness of the base plate is stably maintained by isolating the coupling elastic pad;

[0028] (3) The "boot-style" design of the top plate and the coupling bottom plate is achieved by adjusting the thickness and stiffness of the rubber layer between the top plate and the coupling bottom plate and vulcanizing the entire plate to maintain the lateral stiffness of the coupling pad. The "boot-style" design described in the present invention refers to the concave-convex matching structure of the sleeve on the top plate and the sleeve on the coupling bottom plate.

[0029] That is: a shear-type railway turnout vibration damping fastener with adjustable stiffness, including a gauge block 4, spring bars or other fasteners 6 for clamping rails, flat washers 7, and nuts 8. A double-layer coupling plate 1 is provided between the back of the railway turnout and the switch sleeper. Holes for screwing to the switch sleepers are opened on both sides of the double-layer coupling plate 1. The switch sleeper bolts 9 pass through the spring washers 5 and the center holes of the adjustable cover plate to fix the adjustable cover plate 3 and the double-layer coupling plate 1 to the bolt holes in the switch sleeper.

[0030] The double-layer coupling pad consists of a top plate, a bonding rubber layer, and a coupling bottom plate. The structural diagram is shown in the figure. Figure 2 and Figure 3 As shown, the double-layer coupling pad 1 consists of a top plate 11, an adhesive rubber layer 12, and a coupling bottom plate 13. The adhesive rubber layer 12 is located between the top plate 11 and the coupling bottom plate 13. The top plate 11 and the coupling bottom plate 13 are integrally formed by a vulcanized adhesive elastic rubber layer 12. A raised sleeve 14 is provided on the coupling bottom plate 13, and the circumferential end surface of the raised sleeve has a concave-convex structure.

[0031] Adjustable cover ( Figure 6-8 ) cooperates with the raised sleeve provided on the coupling base plate, and fully presses and adjusts the direction of the adjustable cover plate through the pad bolts, so as to achieve adjustable stiffness of the double-layer coupling pad. The adjustable cover plate 3 is composed of a center hole cover plate and a sleeve. The upper end hole of the sleeve and the hole in the center hole cover plate form an integral structure. The circumferential end surface of the sleeve is a convex-concave structural surface, and the convex-concave structural surface is in a concave-convex plug-in fit with the concave-convex structural surface of the raised sleeve on the coupling base plate. The adjustable cover plate 3 and the coupling base plate 13 are installed through their respective preset sleeves and the bosses and grooves on the circumferential end surfaces of the sleeves, so that the preload force of the switch tie bolts 9 is directly transferred to the coupling base plate 13, and the vertical stiffness of the pad 2 is kept stable by isolating the coupling elastic pad. The adjustable cover plate 3 cooperates with the raised sleeve provided on the coupling base plate 13, and fully presses and adjusts the direction of the adjustable cover plate 3 through the switch tie bolts 9, so that the stiffness of the double-layer coupling pad 1 is adjustable.

[0032] The measures implemented by the present invention are as follows: (1) The double-layer coupling pad is a vulcanized elastic rubber material bonded between the top plate and the coupling bottom plate to form an integral body. The thickness and stiffness of the elastic element of the fastener system in the three directions A, B, and C are preset through testing and calculation to ensure the stiffness requirements of the fastener system in the three directions. (2) The matching relationship between the compression of the elastic element in the C position (between the top plate and the coupling bottom plate) and the adjustment amount of the adjustable cover plate is controlled and calculated to ensure that the fastener stiffness can be quickly adjusted and stably maintained through the adjustable cover plate during the application of the fastener system.

[0033] Refer to the attached Figure 1 . Figure 1 The three parts involved in the vertical surface indicated by the boxed text can also be designed to cooperate with each other at an angle greater than 90 degrees. This can form two components of the lateral force, one vertical and one lateral, to achieve the purpose of controlling the vertical and lateral stiffness.

[0034] It should be understood that although the above embodiments provide a relatively detailed textual description of the design ideas of the present invention, these textual descriptions are only simple textual descriptions of the design ideas of the present invention, rather than limitations on the design ideas of the present invention. Any combination, addition or modification that does not exceed the design ideas of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A method for eliminating rail corrugation, comprising a gauge block (4), a spring bar (6), a flat washer (7), and a nut (8); a double-layer coupling pad (1) is provided between the back of a railway turnout and a switch sleeper; holes for screwing to the switch sleeper are provided on both sides of the double-layer coupling pad (1); a switch sleeper bolt (9) passes through the spring washer (5) and the center hole of the adjustable cover plate to fix the adjustable cover plate (3) and the double-layer coupling pad (1) to the bolt thread hole in the switch sleeper; the double-layer coupling pad (1) is composed of a top plate (11), a bonding rubber layer (12), and a plurality of other components. 2) is composed of a coupling bottom plate (13), a bonding rubber layer (12) is located between the top plate (11) and the coupling bottom plate (13); a raised sleeve (14) is provided on the coupling bottom plate (13) and the circumferential end surface of the raised sleeve is a concave-convex structure surface; the adjustable cover plate (3) is composed of a central hole cover plate and a sleeve, the upper end surface of the sleeve is opposite to the hole in the central hole cover plate to form an integral structure, the circumferential end surface of the sleeve lower end is a convex-concave structure surface and the convex-concave structure surface is in a concave-convex plug-in fit with the concave-convex structure surface of the raised sleeve on the coupling bottom plate, and its characteristics are: By adjusting the stiffness of the railway turnout vibration damping fasteners and changing the interaction between the wheel and rail, the period and frequency of the parametric excitation vibration can be adjusted to completely solve the periodic corrugation problem. The specific approach is: (1) Use shear-type coupling pads to achieve vibration reduction of the fastener system; (2) The adjustable cover plate and the coupling base plate are installed through a preset sleeve and its bosses and grooves to directly transmit the preload force of the switch tie bolts to the base plate, and the vertical stiffness of the base plate is stably maintained by isolating the coupling elastic pad; (3) Through the concave-convex matching structure of the sleeve on the top plate and the sleeve on the coupling bottom plate, the thickness and stiffness of the overall vulcanized rubber layer between the top plate and the coupling bottom plate are adjusted, so that the lateral stiffness of the coupling pad is stably maintained.

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