A bionic claw-type variable stiffness vibration isolation device for track vibration reduction and a vibration reduction track system

Abstract

The present invention discloses a bionic claw-type variable stiffness vibration isolation device for track vibration reduction and a vibration-reducing track system. The vibration isolation device includes a truncated conical scroll spring that simulates a claw pad, a toe-like linkage mechanism, a base, an inner sleeve, a top cover, a guide column, and the like. The truncated conical scroll spring and a plurality of toe-like linkage mechanisms are arranged in parallel between the top cover and the base, and provide nonlinear positive stiffness and nonlinear negative stiffness within the effective vibration isolation range, respectively. Each toe-like linkage mechanism is composed of two rods of different lengths and a telescopic spring, respectively simulating two phalanges and the muscles around the phalangeal joints. In a vibration-reducing track system using this vibration isolation device, the hardened stiffness of the truncated conical scroll spring can compensate for the negative stiffness of the toe-like linkage mechanism, enabling the vibration isolation device to achieve quasi-zero stiffness within a large load range, reducing the characteristic frequency of the vibration-reducing track, and extending the vibration-reduction frequency band. While improving the low-frequency vibration and noise reduction performance of the track system below 20 Hz, it maintains high load-bearing capacity and stability.

Description

Technical Field

[0001] The present application belongs to the technical field of vibration and noise reduction in rail transit, and relates to a nonlinear vibration reduction track structure based on a bionic concept, and specifically to a bionic claw-type variable stiffness vibration isolation device and a vibration reduction track system for track vibration reduction, so as to realize low-frequency vibration reduction of the track system. Background Art

[0002] With the rapid expansion of the rail transit network and the increase in train traffic and operating speed, the environmental vibration and noise problems caused by running are becoming more and more prominent. The low-frequency vibration components stimulated by rail transit are numerous, decay slowly, and propagate over a wide range. In addition, precision instruments and the human body are very sensitive to low-frequency vibrations below 20Hz. Currently, the commonly used high-level vibration reduction method is floating plate track, but in actual applications, it has also been found that its low-frequency vibration reduction effect is not good. Based on linear vibration theory, floating plate track can only be used for vibrations above 20Hz. It is difficult to effectively control vibrations at times its natural frequency, and at the same time requires a certain support stiffness to ensure driving safety and comfort. As a result, its natural frequency is high, and it is difficult to effectively control low-frequency vibrations below 20Hz, and it may even amplify vibrations around 10Hz.

[0003] One solution to optimizing the low-frequency vibration reduction performance of floating slab tracks in the existing technology is to add a dynamic vibration absorber to the surface of the floating slab. The mass block in the dynamic vibration absorber can be formed by casting a concrete block, and an elastic element (such as a rubber pad) is added between it and the floating slab to form a mass-spring system. By resonating with the floating slab, it absorbs some of the low-frequency vibration energy. At the same time, an inertia mechanism can also be introduced into the dynamic vibration absorber, and its inertia amplification characteristics can be used to achieve mass gain benefits, that is, changing the structural inertia while basically not changing the physical mass. However, it has also been found that this type of technology does not change the inherent parameters and natural frequency of the system, and can only partially alleviate the amplification effect near the natural frequency of the track structure, and still cannot solve the problem of low-frequency vibration control.

[0004] Another mainstream technical solution attempts to perform nonlinear optimization design on the vibration isolators under the track plate: In view of the limitations of the optimization design of traditional linear vibration isolators, nonlinear vibration isolators based on quasi-zero stiffness theory have been developed in large quantities. The positive and negative stiffness elements are matched in parallel, and the negative stiffness design is used to reduce the dynamic natural frequency, so as to achieve load-bearing capacity and dynamic stiffness close to zero at the equilibrium position, thereby ensuring the static load-bearing capacity and widening the low-frequency vibration isolation range. At present, this technology has also begun to be tried in floating plate track vibration reduction measures, including the introduction of horizontal coil springs, disc springs, cam rollers and other mechanisms as negative stiffness elements in parallel with linear springs to achieve quasi-zero stiffness, so as to balance the weight of the floating plate and the train load, and have lower dynamic stiffness at the equilibrium position under the train load, thereby reducing the natural frequency of the system and suppressing the low-frequency vibration components in the floating plate. However, there are also some problems to be solved. The nonlinear characteristics of quasi-zero stiffness isolators are usually strong, and the quasi-zero stiffness range and bearing capacity are limited. Reasonable parameter design is needed to control the nonlinear level and stability. However, this type of structure has fewer adjustable parameters, weak controllability, and only guarantees the bearing capacity. Summary of the Invention

[0005] To address the above issues, and inspired by the excellent vibration suppression and impact resistance capabilities of biological structures in complex dynamic environments, the present invention aims to develop a bionic claw-type variable-stiffness vibration isolation device and vibration-damping track system for track vibration reduction, inspired by the structure of feline toes. The toe structure is simulated by two rods of different lengths (simulating phalanges) and a linear telescopic spring (simulating muscle), while the foot pad tissue is simulated by a truncated conical scroll spring with hardened stiffness. The overall stiffness of the vibration isolation device is achieved by compensating the nonlinear negative stiffness of the toe-like linkage mechanism and the hardened stiffness of the truncated conical scroll spring. Therefore, the bionic claw-type variable-stiffness vibration isolation device of the present invention can achieve quasi-zero stiffness over a wide load range, reduce the characteristic frequency of the vibration-damping track, and extend the vibration-damping frequency band. This improves the track structure's low-frequency vibration and noise reduction performance below 20 Hz while maintaining high load capacity and stability.

[0006] To achieve the above object, the present invention is implemented through the following technical solutions:

[0007] Technical solution 1:

[0008] A bionic claw-type variable stiffness vibration isolation device for rail vibration reduction comprises: a base 3-12, an inner sleeve 3-5, a top cover 3-7, a guide post 3-3, an annular limit stop 3-8, a truncated cone scroll spring 3-1, a toe-like connecting rod mechanism 3-2, an adjustment pad 3-4, a damping piston, a damping seal 3-10, and a damping fluid 3-11; the truncated cone scroll spring 3-1 and the toe-like connecting rod mechanism 3-2 are combined and arranged in parallel between the top cover 3-7 and the base 3-12, and respectively provide nonlinear positive stiffness and nonlinear negative stiffness within an effective vibration isolation range; wherein:

[0009] The bottom of the inner sleeve 3-5 is fixed to the center of the base 3-12;

[0010] The top cover 3-7 is located above the inner sleeve 3-5, with a guide post 3-3 connected to the center of the bottom of the top cover, and an annular limit stop 3-8 provided on the bottom edge of the top cover; the guide post 3-3 extends into the inner sleeve 3-5, and the annular limit stop 3-8 is located outside the top of the inner sleeve 3-5, leaving a movable space between the top of the inner sleeve 3-5 and the bottom of the top cover 3-7;

[0011] The truncated cone vortex spring 3-1 provides nonlinear positive stiffness and is vertically arranged in the inner sleeve 3-5. An adjusting pad 3-4 is provided between the bottom of the truncated cone vortex spring 3-1 and the bottom of the inner sleeve 3-5. The upper end of the truncated cone vortex spring 3-1 is in elastic contact with the bottom of the guide column 3-3. The truncated cone vortex spring 3-1 has a nonlinear segmented stiffness characteristic: it exhibits linear stiffness at small displacements and hardened stiffness at large displacements. The appropriate pre-compression amount can be adjusted by adjusting the pad 3-4. The truncated cone scroll spring 3-1 can achieve progressive hardening of stiffness, making it close to the biomechanical properties of the paw fat pad and maintaining high load-bearing capacity;

[0012] The toe-like linkage mechanism 3-2 provides nonlinear negative stiffness. Several toe-like linkage mechanisms 3-2 are evenly arranged in a ring around the outer side of the inner sleeve 3-5 between the top cover 3-7 and the base 3-12, providing greater load-bearing capacity and stiffness adjustment function.

[0013] The damping piston includes a damping connecting rod 3-9-1 and a damping plate 3-9-2 connected to the bottom of the damping connecting rod 3-9-1, and a plurality of damping channels are distributed on the damping plate 3-9-2; the upper end of the damping connecting rod 3-9-1 is connected to the bottom of the guide column 3-3, and the lower end extends into the inner cavity of the truncated cone scroll spring 3-1, and the lower end of the damping connecting rod 3-9-1 and the damping plate 3-9-2 are immersed in the damping fluid 3-11 together to provide a damping effect for the vibration isolation device; the damping fluid 3-11 is loaded in the inner sleeve 3-5 and is sealed by installing a damping seal 3-10 between the inner sleeve 3-5 and the guide column 3-3.

[0014] Furthermore, the toe-like linkage mechanism 3-2 is composed of two rods of different lengths and a high-strength telescopic spring 3-2-2, which respectively simulate two phalanges and the muscles around the phalangeal joints, and have a stiffness adjustment function; the two rods of different lengths are the first rod 3-2-1 and the second rod 3-2-3, one end of the first rod 3-2-1 is hinged to the slider 3-14 on the outside of the inner sleeve 3-5, the slider 3-14 is connected to the annular limit stop 3-8 at the bottom edge of the top cover 3-7, the other end of the first rod 3-2-1 is connected to one end of the telescopic spring 3-2-2, and the other end of the telescopic spring 3-2-2 is connected to the second rod 3-2-3; one end of the second rod 3-2-3 is hinged to the first rod 3-2-1, and the other end is installed on the base 3-12 through a hinge support.

[0015] Furthermore, both ends of the telescopic spring 3-2-2 are fixed between the first rod 3-2-1 and the second rod 3-2-3 by means of hooks.

[0016] Furthermore, it also includes a plurality of directional guide rails 3-6, which are vertically arranged on the outside of the inner sleeve 3-5 and adapted to the position of the toe-like linkage mechanism 3-2, and are used to orient the slider hinged at the end of the first rod 3-2-1 of the toe-like linkage mechanism 3-2 so that the toe-like linkage mechanism 3-2 moves in the vertical direction.

[0017] Furthermore, the inner sleeve 3-5 installed on the upper part of the base 3-12 divides the base 3-12 into an outer ring part and an inner circle part occupied by the inner sleeve 3-5. The outer ring part of the base is provided with a plurality of equidistant mounting holes 3-13 along the radial direction. The hinge support connected to the end of the second rod 3-2-3 of the toe-like linkage mechanism 3-2 is installed on the base 3-12 through the mounting hole 3-13 to adjust the movement posture of the toe-like linkage mechanism 3-2.

[0018] Technical solution 2:

[0019] A vibration-damping track system using the bionic claw-type variable stiffness vibration isolation device for track vibration reduction comprises a base track bed 1, a track plate 2, rails 8, fasteners 9, and a plurality of vibration isolation components arranged inside the track plate 2;

[0020] The rail 8 is arranged on the track plate 2 through the fastener 9;

[0021] The vibration isolation assembly includes an outer sleeve 4 cast in the track plate 2 and the bionic claw-type variable stiffness vibration isolation device 3 installed in the outer sleeve 4; the vibration isolation assembly is symmetrically arranged on both sides of the track plate 2 along the center line in the transverse direction of the track plate 2 and is evenly spaced along the length direction of the track plate 2 (the direction of train travel);

[0022] The vibration isolation assembly lifts the track plate 2 and floats it on the basic roadbed 1.

[0023] Specifically, the top cover 3-7 of the bionic claw-type variable stiffness vibration isolation device lifts the track plate 2 through the internal support structure of the outer sleeve 4 and floats it on the basic roadbed 1. A gasket 5 for adjusting the height of the track plate is installed between the internal support structure of the outer sleeve 4 and the top cover 3-7. A moving range is left between the top cover and the top end of the inner sleeve, and the moving range is ensured to be less than the lifting distance of the track plate, so as to limit the maximum safe displacement of the vibration-damping track.

[0024] A buckle 6 is welded on the outer wall of the outer sleeve 4 for being cast into the track plate 2 for fixing;

[0025] The base 3 - 12 of the bionic claw type variable stiffness vibration isolation device is fixed on the surface of the basic roadbed 1 below the corresponding outer sleeve 4 .

[0026] Furthermore, the vibration isolation assembly also includes an insulating cover plate 7 , which is arranged above the outer sleeve 4 .

[0027] Furthermore, the bionic claw-type variable stiffness vibration isolation device is used to reduce the vibration response of the vibration-damping track system in the low-frequency band and maintain a high load-bearing capacity.

[0028] By adopting the above technical solution, the present invention has the following beneficial effects:

[0029] 1. Based on the quasi-zero stiffness vibration isolation principle, a bionic claw-type variable stiffness vibration isolation device for track vibration reduction is introduced, which includes a mutual compensation mechanism between nonlinear negative stiffness and nonlinear positive stiffness. This increases the number and controllability of controllable parameters, and can achieve a wider range of quasi-zero stiffness range for the track plate at the vibration equilibrium position, so that the vibration-damping track system has a lower starting vibration isolation frequency and a wider vibration isolation frequency band.

[0030] 2. The vibration-damping track system using the bionic claw-type variable stiffness vibration isolation device proposed by the present invention, at the load balance position, the internal toe-shaped connecting rod mechanism and truncated cone scroll spring will jointly provide a positive restoring force, which has a greater load-bearing capacity.

[0031] 3. The bionic claw-type variable stiffness vibration isolation device proposed in the present invention has nonlinear hardening stiffness when far away from the equilibrium position. The rapidly increasing restoring force reacts on the track plate to ensure that it does not undergo excessive displacement, without affecting the safety and stability of the vibration-damping track system.

[0032] 4. The vibration reduction track system using the bionic claw-type variable stiffness vibration isolation device proposed in the present invention has a vibration reduction performance that is insensitive to the excitation amplitude and has a higher sensitivity to damping, and has good engineering application potential. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1This is an assembly diagram showing the connection relationship of components of the bionic claw-type variable stiffness vibration isolation device for track vibration reduction according to the present invention;

[0034] Figure 2 This is a schematic diagram of the internal component structure of the inner sleeve of the bionic claw-type variable stiffness vibration isolation device for track vibration reduction of the present invention;

[0035] Figure 3 This is a schematic diagram of the inner sleeve structure of the bionic claw-type variable stiffness vibration isolation device for track vibration reduction of the present invention;

[0036] Figure 4 It is a schematic diagram of the mechanical model of the working mechanism of the bionic claw type variable stiffness vibration isolation device for track vibration reduction of the present invention;

[0037] Figure 5 This is a dimensionless restoring force-displacement curve of the bionic claw-type variable stiffness vibration isolation device for track vibration reduction under a monotonic load;

[0038] Figure 6 2. It is a cross-sectional schematic diagram of a vibration reduction track system using a bionic claw-type variable stiffness vibration isolation device according to the present invention;

[0039] Figure 7 This is a schematic diagram of the structure of the bionic claw type variable stiffness vibration isolation device for track vibration reduction of the present invention installed in the track plate;

[0040] Figure 8 It is a dynamic calculation model of the vehicle-bionic structure vibration reduction track coupling system;

[0041] Figure 9 The amplitude-frequency curve of the track plate vibration response before and after the application of the bionic claw type variable stiffness vibration isolation device;

[0042] Figure 10 This is a one-third octave band diagram of the acceleration level of the foundation roadbed before and after the application of the bionic claw-type variable stiffness vibration isolation device;

[0043] Figure 11 It is the time history curve of the vertical displacement of the track plate before and after the application of the bionic claw type variable stiffness vibration isolation device.

[0044] Reference numerals:

[0045] 1 Basic roadbed; 2 Track slab;

[0046] 3 Bionic claw-type variable stiffness vibration isolation device; 3-1 truncated cone scroll spring; 3-2 Toe-shaped linkage mechanism; 3-2-1 First rod; 3-2-2 Telescopic spring; 3-2-3 Second rod; 3-3 Guide column; 3-4 Adjustment pad; 3-5 Inner sleeve; 3-6 Directional guide rail; 3-7 Top cover; 3-8 Annular limit stop; 3-9-1 Damping connecting rod; 3-9-2 Damping disc; 3-10 Damping seal; 3-11 Damping fluid; 3-12 Base; 3-13 Mounting hole; 3-14 Slider;

[0047] 4 outer sleeve; 5 gasket; 6 snap fastener; 7 insulating cover; rail 8; fastener 9. DETAILED DESCRIPTION

[0048] The technical solution provided by this application will be further described below in conjunction with specific embodiments and accompanying drawings. The advantages and features of this application will become more apparent with reference to the following description.

[0049] Example 1

[0050] This embodiment provides a bionic claw-type variable stiffness vibration isolation device for track vibration reduction.

[0051] like Figure 1 、 Figure 2 、 Figure 3 As shown, the bionic claw-type variable stiffness vibration isolation device 3 includes: a base 3-12, an inner sleeve 3-5, a top cover 3-7, a guide column 3-3, an annular limit stop 3-8, a truncated cone scroll spring 3-1, a toe-like connecting rod mechanism 3-2, an adjustment pad 3-4, a damping piston, a damping seal 3-10, and a damping fluid 3-11; the truncated cone scroll spring 3-1 and the toe-like connecting rod mechanism 3-2 are combined and arranged in parallel between the top cover 3-7 and the base 3-12, and respectively provide nonlinear positive stiffness and nonlinear negative stiffness within the effective vibration isolation range; wherein:

[0052] The bottom of the inner sleeve 3-5 is fixed to the center of the base 3-12;

[0053] The top cover 3-7 is located above the inner sleeve 3-5, with a guide post 3-3 connected to the center of the bottom of the top cover, and an annular limit stop 3-8 provided on the bottom edge of the top cover; the guide post 3-3 extends into the inner sleeve 3-5, and the annular limit stop 3-8 is located outside the top of the inner sleeve 3-5, leaving a movable space between the top of the inner sleeve 3-5 and the bottom of the top cover 3-7;

[0054] The truncated cone vortex spring 3-1 provides nonlinear positive stiffness and is vertically arranged in the inner sleeve 3-5. An adjusting pad 3-4 is provided between the bottom of the truncated cone vortex spring 3-1 and the bottom of the inner sleeve 3-5. The upper end of the truncated cone vortex spring 3-1 is in elastic contact with the bottom of the guide column 3-3. The truncated cone vortex spring 3-1 has a nonlinear segmented stiffness characteristic: it exhibits linear stiffness at small displacements and hardened stiffness at large displacements. The appropriate pre-compression amount can be adjusted by adjusting the pad 3-4. The truncated cone scroll spring 3-1 can achieve progressive hardening of stiffness, making it close to the biomechanical properties of the paw fat pad and maintaining high load-bearing capacity;

[0055] The toe-like linkage mechanism 3-2 provides nonlinear negative stiffness. Several toe-like linkage mechanisms 3-2 are evenly arranged in a ring around the outer side of the inner sleeve 3-5 between the top cover 3-7 and the base 3-12, providing greater load-bearing capacity and stiffness adjustment function.

[0056] The damping piston includes a damping connecting rod 3-9-1 and a damping plate 3-9-2 connected to the bottom of the damping connecting rod 3-9-1, and a plurality of damping channels are distributed on the damping plate 3-9-2; the upper end of the damping connecting rod 3-9-1 is connected to the bottom of the guide column 3-3, and the lower end extends into the inner cavity of the truncated cone scroll spring 3-1; the lower end of the damping connecting rod 3-9-1 and the damping plate 3-9-2 are immersed in the damping fluid 3-11 together to provide a damping effect for the vibration isolation device; the damping fluid 3-11 is loaded in the inner sleeve 3-5, and is sealed by installing a damping seal 3-10 between the inner sleeve 3-5 and the guide column 3-3 to prevent the damping fluid from overflowing.

[0057] Furthermore, the toe-like linkage mechanism 3-2 is composed of two rods of different lengths and a high-strength telescopic spring 3-2-2, which respectively simulate two phalanges and the muscles around the phalangeal joints, and have a stiffness adjustment function; the two rods of different lengths are the first rod 3-2-1 and the second rod 3-2-3, one end of the first rod 3-2-1 is hinged to the slider 3-14 on the outside of the inner sleeve 3-5, and the slider is connected to the annular limit stop 3-8 at the bottom edge of the top cover 3-7, the other end of the first rod 3-2-1 is connected to one end of the telescopic spring 3-2-2, and the other end of the telescopic spring 3-2-2 is connected to the second rod 3-2-3; one end of the second rod 3-2-3 is hinged to the first rod 3-2-1, and the other end is installed on the base 3-12 through a hinge support.

[0058] Furthermore, the hinged connection between the first rod 3-2-1, the second rod 3-2-3, the base 3-12 and the inner sleeve 3-5 can rotate, and both ends of the telescopic spring 3-2-2 are fixed between the two rods by a hook.

[0059] Furthermore, it also includes a plurality of directional guide rails 3-6, which are vertically arranged on the outside of the inner sleeve 3-5 and adapted to the position of the toe-like linkage mechanism 3-2, and are used to orient the slider hinged at the end of the first rod 3-2-1 of the toe-like linkage mechanism 3-2 so that the toe-like linkage mechanism 3-2 moves in the vertical direction.

[0060] Furthermore, the inner sleeve 3-5 installed on the upper part of the base 3-12 divides the base 3-12 into an outer ring part and an inner circle part occupied by the inner sleeve 3-5. The outer ring part of the base is provided with a plurality of equidistant mounting holes 3-13 along the radial direction. The hinge support connected to the end of the second rod 3-2-3 of the toe-like linkage mechanism 3-2 is installed on the base 3-12 through the mounting hole 3-13 to adjust the movement posture of the toe-like linkage mechanism 3-2.

[0061] In this embodiment, a bionic claw-type variable stiffness vibration isolation device assembly form for track vibration reduction is provided: four directional guide rails 3-6 are evenly installed on the outside of the inner sleeve 3-5, and the annular limit stop 3-8 on the bottom edge of the top cover 3-7 is connected to four sliders, and the four sliders are installed on the four directional guide rails 3-6. Four toe-shaped connecting rod mechanisms 3-2 are evenly distributed in a ring shape at 90° and are respectively hinged to the four sliders.

[0062] The truncated cone scroll spring 3-1 and the toe-shaped connecting rod mechanism 3-2 are combined in parallel and provide nonlinear positive stiffness and nonlinear negative stiffness respectively within the effective vibration isolation range. They are two key components for realizing the quasi-zero stiffness (QZS) characteristics of the bionic claw-type variable stiffness vibration isolation device; the nonlinearities after the two components are matched will weaken each other, so that the overall stiffness of the bionic claw-type variable stiffness vibration isolation device 3 tends to zero within the effective vibration isolation range, forming a wider quasi-zero stiffness (QZS) range, and having excellent low-frequency vibration reduction performance, including a lower starting vibration isolation frequency and a wider vibration isolation frequency band.

[0063] In the quasi-zero stiffness (QZS) position, the truncated cone scroll spring 3 - 1 and the toe-shaped connecting rod mechanism 3 - 2 jointly provide a positive restoring force and have a high load-bearing capacity.

[0064] Specifically, the truncated cone scroll spring is a mature device in the industry, and the inner and outer radii are r i and r o , the effective number of coils is n , the rotation angle relative to the outer radius The cross-sectional length and width are b and c , the shear modulus is G , the helix angle is α ; Initial bottoming load of truncated cone scroll spring P1 and the corresponding compression deformation u 1 has the following expressions:

[0065] (1)

[0066] in When the deformation is less than the initial bottoming deformation u At 1, the inner spring has not bottomed out, so synchronous motion occurs and the overall stiffness is linear. P 1 / u 1; When the deformation reaches u 1, after completing the maximum compression u 2. Before, the inner spring began to touch the bottom from the outside to the inside, and the stiffness gradually increased. The overall performance was nonlinear hardening stiffness, with nonlinear restoring force. F 1 is as follows:

[0067] (2)

[0068] Use pre-compression As an adjustment parameter, the equivalent hardening positive stiffness of the truncated cone scroll spring can be continuously adjusted by adjusting the pad 3-4, and the nonlinear negative stiffness provided by the toe-like linkage mechanism 3-2 can be balanced near the quasi-zero stiffness (QZS) position.

[0069] Specifically, if Figure 4 As shown, when the toe-like linkage mechanism moves vertically along the directional guide rail 3-6, there is relative rotation between the two rods, resulting in linear deformation of the telescopic spring. Due to the geometric nonlinearity of the structure, an asymmetric nonlinear restoring force is provided in the vertical direction.

[0070] Further, such as Figure 4 As shown, the first rod 3-2-1 and the second rod 3-2-3 are hinged at point O. The length of the first rod 3-2-1 is ( l 1+ l 2), the length of the second rod 3-2-3 is ( l 3+ l 4), among which, l 1 is the distance from the connection point between the first rod 3-2-1 and the telescopic spring 3-2-2 to point O, l 2 is the distance from the other end point of the first rod 3-2-1 to point O, l 3 is the distance from the connection point between the telescopic spring 3-2-2 and the second rod 3-2-3 to point O, l 4 is the distance from the connection point of the telescopic spring 3-2-2 and the second rod 3-2-3 to the other end of the second rod 3-2-3; the length of the telescopic spring 3-2-2 x 0, the initial installation angle and the initial angle of the rod are α 0 and β0, the installation span is d ; F(t) The time-varying load borne by the bionic claw type variable stiffness vibration isolation device; the load-bearing object m Displacement occurs y When the truncated cone scroll spring is compressed, the height is h 0 becomes h The relative rotation between the two rods in the toe-like linkage mechanism causes the linear telescopic spring 3-2-2 to deform. The length of the telescopic spring 3-2-2 after deformation is x , the installation angle and the rod angle are α and β Although the telescopic spring 3-2-2 undergoes linear deformation, due to the geometric nonlinearity of the structure, the toe-like linkage mechanism ultimately provides a dimensionless nonlinear restoring force in the vertical direction. F 2 is as follows:

[0071] (3)

[0072] The nonlinear stiffness characteristics of the toe-like linkage mechanism can be flexibly designed and adjusted through structural parameters, including: rod length ratio λ = l 2 / ( l 3+ l 4) Relative span p = d / ( l 3+ l 4) Initial installation angle β 0, spring constraint position, etc., the spring constraint position is through two connection length ratios s 1. s 2 means, s 1= l 1 / ( l 3+ l 4), s 2= l 3 / ( l 3+ l 4). Vertical dimensionless displacement Y Related to the above parameters, it is expressed as

[0073] Figure 5 Provided is a dimensionless restoring force of a bionic claw type variable stiffness vibration isolation device for track vibration reduction F With displacement Y The change process includes the following three stages:

[0074] Phase 1: The toe-like linkage first deforms to provide the main restoring force F 2. As the deformation increases, the restoring force of the toe-like linkage mechanismF 2 increases rapidly. At this stage, the inner ring of the truncated cone scroll spring has not yet bottomed out and provides a very weak restoring force. F 1. The bearing capacity of the vibration isolation device is mainly provided by the toe-shaped linkage mechanism.

[0075] Phase 2: With further compression and deformation, the inner ring of the truncated cone scroll spring gradually hardens after bottoming out to provide stronger support force. F 1. At this time, the toe-like linkage mechanism enters the negative stiffness range, thereby performing stiffness compensation and effectively maintaining the load-bearing capacity of the system. The wide effective vibration isolation range ∆ x Low dynamic stiffness of the vibration isolation device is achieved within.

[0076] Phase 3: Compression deformation continues, and the toe-like linkage mechanism provides restoring force F 2 becomes smaller, and the truncated cone scroll spring provides a stronger restoring force due to stiffness hardening F 1. The bionic claw type variable stiffness vibration isolation device shows stiffness hardening characteristics as a whole, and the nonlinear restoring force ( F 1+ F 2) The deformation increases rapidly with compression.

[0077] In a preferred embodiment,

[0078] The truncated cone scroll spring 3-1 adopts the form of equal helix angle, the material is 60sA2M, and the inner and outer radii are r i = 18mm and r o = 50mm, the length and width of the cross section are b = 38mm and c = 4mm, number of coils n =5;

[0079] The length of the rods in the toe-like linkage mechanism 3-2 is: the length of the first rod is l 1+ l 2. The length of the second rod is l 3+ l 4, among which l 1= 40mm, l 2= ​​144mm, l 3= 42mm, l 4 = 40mm; the stiffness of the telescopic spring 3-2-2 is 1.08kN / mm, and the installation span is set to d = 120mm, initial angle of the member β 0 is approximately 2 π / 3; at this point, the initial motion posture of the toe-like linkage mechanism can be determined;

[0080] Viscous silicone oil damping fluid is used, and the damping disc 3-9-2 extends into the inner cavity of the truncated cone scroll spring and is immersed in the damping fluid. The damping channel of the damping disc adopts an "S-shaped structure flow channel", and the equivalent damping is approximately , to ensure the working performance of the truncated cone scroll spring in the damping fluid;

[0081] The top cover 3-7 is made of 430 type ferritic stainless steel, which is corrosion-resistant and has good ductility. Its diameter is 240mm and thickness is 5mm.

[0082] Example 2

[0083] This embodiment provides a vibration reduction track system and a vibration reduction method using the bionic claw-type variable stiffness vibration isolation device for track vibration reduction of the above-mentioned embodiment 1.

[0084] like Figure 6 As shown, a vibration reduction track system using a bionic claw-type variable stiffness vibration isolation device, hereinafter referred to as a bionic structure vibration reduction track for ease of description, comprises a basic roadbed 1, a track plate 2, rails 8, fasteners 9, and a plurality of vibration isolation components arranged inside the track plate 2;

[0085] The rail 8 is arranged on the track plate 2 through the fastener 9;

[0086] The vibration isolation assembly includes an outer sleeve 4 cast in the track plate 2 and the bionic claw-type variable stiffness vibration isolation device 3 installed in the outer sleeve. The bionic claw-type variable stiffness vibration isolation device 3 reduces the vibration response of the vibration-damping track system in the low-frequency band and maintains a high load-bearing capacity. The vibration isolation assemblies are arranged symmetrically on both sides of the track plate 2 along the midline in the transverse direction of the track plate 2 and are evenly spaced along the length direction of the track plate 2 (the direction of train travel). The adjacent spacing is set to 1.2-1.5m. In the embodiment, the adjacent spacing is set to 1.25m.

[0087] The vibration isolation assembly lifts the track plate 2 and floats it on the basic roadbed 1.

[0088] Specifically, such as Figure 7 As shown, the top cover 3-7 of the bionic claw-type variable stiffness vibration isolation device is used to support the deadweight of the track structure and transfer the load. The track plate 2 is lifted and floated on the basic roadbed 1 by the internal support structure of the outer sleeve 4. A gasket 5 for adjusting the height of the track plate is installed between the internal support structure of the outer sleeve 4 and the top cover 3-7. A movable range is left between the top cover and the top end of the inner sleeve, and the movable range is ensured to be less than the lifting distance of the track plate to limit the maximum safe displacement of the vibration-damping track.

[0089] A buckle 6 is welded on the outer wall of the outer sleeve 4 for being cast into the track plate 2 for fixing;

[0090] The base 3 - 12 of the bionic claw type variable stiffness vibration isolation device is fixed on the surface of the basic roadbed 1 below the corresponding outer sleeve 4 .

[0091] Furthermore, the vibration isolation assembly also includes an insulating cover plate 7 , which is arranged above the outer sleeve 4 .

[0092] Furthermore, this embodiment also provides a vibration reduction method for the vibration reduction track system (i.e., bionic structure vibration reduction track) using the bionic claw-type variable stiffness vibration isolation device.

[0093] In order to describe the vertical vibration response of the bionic structure vibration damping track under the action of train load, a dynamic calculation model of the vehicle-bionic structure vibration damping track coupling system is established, which is referred to as the bionic structure vibration damping track dynamic model. Figure 8 As shown, it includes a vehicle subsystem and a track subsystem, wherein the train in the vehicle subsystem moves at a speed of v Driving, wheelbase, car spacing and adjacent car wheelbase are w a 、 w b and w c In the track subsystem, several bionic claw-type variable stiffness vibration isolation devices with nonlinear restoring force are set between each track plate and the basic roadbed. The two subsystems are coupled and connected through the wheel-rail interaction. The transfer characteristics of the dynamic interaction between the wheel and rail in the vertical direction when the train passes through the track can be calculated. Figure 8 middle, P represents the wheel-rail force.

[0094] For a steel spring floating plate track, a steel spring vibration isolator is installed between each track plate and the basic roadbed. The corresponding dynamic calculation model of the vehicle-track coupling system is the steel spring floating plate track dynamic model.

[0095] In order to illustrate the calculation method of the nonlinear restoring force of the bionic claw-type variable stiffness vibration isolation device, the modeling process of the rail and the subgrade is not described in detail. Here, the track plate is taken as an example. The track plate is modeled as a finite-length Euler beam with a free end. Its vertical vibration differential equation is:

[0096] (4)

[0097] in is the track slab bending stiffness, and denote the mass and length of the track plate respectively, It represents the vertical vibration displacement of the track plate, and the fastener force is recorded as The restoring force provided by the bionic claw type variable stiffness vibration isolation device is recorded as the support reaction force , Along the track length l The total number of fasteners, the fastener positions are determined by express, and The number and position coordinates of bionic claw-type variable stiffness vibration isolation devices under each track plate.

[0098] In order to calculate the bionic structural vibration reduction track dynamic model that introduces the nonlinear restoring force of the bionic claw type variable stiffness vibration isolation device, the nonlinear restoring force of the bionic claw type variable stiffness vibration isolation device can be separated into a nonlinear component related to the high-order displacement and velocity. According to the dynamic equilibrium conditions of the track subsystem at the start and end of any integration period, the matrix expression of the incremental equilibrium form of the track subsystem vibration differential equation is established:

[0099] (5)

[0100] Where, 、 、 are the increases of displacement, velocity and acceleration vectors of all degrees of freedom of the track subsystem in the nth time period respectively; and are the nonlinear increments of stiffness and damping matrix during the period respectively; is the external excitation vector of the track subsystem; M t is the mass matrix of the track subsystem; is the component in the stiffness matrix that is independent of the higher-order displacement; is the component in the damping matrix that is independent of the high-order velocity; 、 are the displacement and velocity vectors of all degrees of freedom respectively.

[0101] The wheel-rail interaction can be determined using Hertz's nonlinear elastic contact theory, expressed as

[0102] (6)

[0103] in: G Indicates the wheel-rail contact coefficient, in m / N 2 / 3 . Indicates the i Carriage No. j The elastic compression between the wheel and rail at each wheel position, including static wheel compression. express t Moment i Carriage No. j The wheel-rail force at each wheel position.

[0104] The subway vehicle adopts the common subway type A vehicle parameters, with an operating speed of 80km / h, a four-car marshaling, and a total vehicle length of 24.4m. The track irregularity adopts the American level 6 spectrum with a wavelength of 1 to 30m, and superimposed short-wave irregularity with a wavelength of 0.05 to 1m. The structural parameters of the bionic structure vibration reduction track refer to the structural parameters of the floating plate track, and the rail adopts the bending stiffness E r I r for , unit mass m r is 60.64kg / m, and the fastener stiffness and damping are 40kN / mm and The fastener spacing is 0.625m, and the track plate adopts bending stiffness E s I s for Length × width × height: 25 × 3.2 × 0.5m, density: 2500kg / m 3 The spacing between bionic claw-type variable stiffness vibration isolation devices is 1.25m, and the basic roadbed is simplified to a beam-slab structure, using bending stiffness E b I b 2.8×10 7 Length × width × height: 25 × 3.2 × 0.2m, density: 2500kg / m 3 , distributed stiffness and damping is 4200

[0105] Taking the traditional linear steel spring floating plate track as a comparison, the steel spring stiffness is 10 kN / mm, and Matlab software is used to perform numerical programming calculations on the bionic structure vibration reduction track dynamic model and the steel spring floating plate track dynamic model. Figure 9 The distribution of the vibration acceleration response of the track plate in the frequency domain is shown in FIG. 1 , and it can be seen that the characteristic frequency of the vibration-damping track system using the bionic claw-type variable stiffness vibration isolation device of the present invention is reduced from 10 Hz to 8.2 Hz, which has a lower starting vibration isolation frequency. Figure 10 It can be seen that the vibration amplification effect of the original floating plate track characteristic frequency of 10Hz is effectively alleviated by the vibration damping track system using the bionic claw-type variable stiffness vibration isolation device, and the total energy in this frequency band is reduced by an average of about 9.6dB. In addition, the acceleration vibration level in multiple frequency bands such as 4-6.3Hz and 12.5-20Hz is significantly reduced. The low-frequency vibration reduction performance of the vibration damping track system below 20Hz is improved, and the vibration reduction frequency band is extended. Figure 11 The maximum displacement of the middle track plate increased slightly from 2.56mm to 2.73mm, but did not exceed the "Floating Plate Track Technical Specifications" The maximum vertical vibration displacement limit of the floating plate is 3mm as specified in the specification. This is because the high static and low dynamic stiffness and hardened stiffness characteristics of the bionic claw-type variable stiffness vibration isolation device ensure that the track plate will not deviate from the equilibrium position and cause excessive static and dynamic displacements, which will not affect the bearing performance and safety of the vibration-damping track system.

[0106] In summary, the vibration reduction track system using the bionic claw type variable stiffness vibration isolation device has excellent low-frequency vibration reduction performance. Since the track structure is subjected to different loads under different working conditions such as different lines and different train models, the stiffness variation range, installation quantity and adjacent spacing of the bionic claw type variable stiffness vibration isolation device 3 can be designed according to specific conditions (such as the weight of the track plate and the train axle weight, etc.); the vibration equilibrium position of the bionic claw type variable stiffness vibration isolation device is designed to be Figure 5 At the dot marked QZS in the middle, the nonlinear positive stiffness and nonlinear negative stiffness provided by the combination of the truncated cone scroll spring and the toe-shaped connecting rod mechanism weaken each other and tend to zero at the vibration equilibrium position, achieving low-frequency vibration reduction of the vibration-damping track system to meet different usage environments and requirements.

[0107] Preferably, regardless of how the toe-like linkage 3-2 is adjusted, by adjusting the pad 3-4 to set an appropriate initial compression, the truncated conical scroll spring 3-1 can always provide appropriate positive stiffness for nonlinear compensation. For designs with a quasi-zero stiffness range and rated load, it is recommended to first adjust the toe-like linkage 3-2, and then adjust the truncated conical scroll spring 3-1 to implement nonlinear compensation. This allows the bionic claw-type variable stiffness vibration isolation device to achieve a wide range of quasi-zero stiffness with minimal static deformation, thereby improving the load-bearing capacity of the vibration-damping track system and making it particularly suitable for low-frequency vibration reduction under heavy loads.

[0108] The above description is only a description of the preferred embodiments of the present application and does not limit the scope of the present application. Any changes or modifications made by any person skilled in the art based on the above disclosed technical content should be regarded as equivalent valid embodiments and fall within the scope of protection of the technical solution of the present application.

Claims

1. A bionic claw-type variable stiffness vibration isolation device for track vibration reduction, characterized in that: include: A base (3-12), an inner sleeve (3-5), a top cover (3-7), a guide column (3-3), an annular limit stop (3-8), a truncated cone scroll spring (3-1), a toe-like connecting rod mechanism (3-2), an adjustment pad (3-4), a damping piston, a damping seal (3-10), and a damping fluid (3-11); the truncated cone scroll spring (3-1) and the toe-like connecting rod mechanism (3-2) are arranged in parallel between the top cover (3-7) and the base (3-12), and respectively provide nonlinear positive stiffness and nonlinear negative stiffness within an effective vibration isolation range; wherein: The bottom of the inner sleeve (3-5) is fixed to the center of the base (3-12); The top cover (3-7) is located above the inner sleeve (3-5), a guide column (3-3) is connected to the center of the bottom of the top cover, and an annular limit stop (3-8) is provided on the bottom edge of the top cover; the guide column (3-3) extends into the inner sleeve (3-5), the annular limit stop (3-8) is located outside the top of the inner sleeve (3-5), and a movable range is left between the top of the inner sleeve (3-5) and the bottom of the top cover (3-7); The truncated cone vortex spring (3-1) provides nonlinear positive stiffness and is vertically arranged in the inner sleeve (3-5). An adjustment pad (3-4) is arranged between the bottom of the truncated cone vortex spring (3-1) and the bottom of the inner sleeve (3-5). The upper end of the truncated cone vortex spring (3-1) is in elastic contact with the lower side of the guide column (3-3). The toe-like connecting rod mechanism (3-2) provides nonlinear negative stiffness, and a plurality of the toe-like connecting rod mechanisms (3-2) are evenly arranged in a ring around the outside of the inner sleeve (3-5) between the top cover (3-7) and the base (3-12), providing greater load-bearing capacity and stiffness adjustment function; The damping piston comprises a damping connecting rod (3-9-1) and a damping disc (3-9-2) connected to the bottom of the damping connecting rod (3-9-1), and a plurality of damping channels are distributed on the damping disc (3-9-2); the upper end of the damping connecting rod (3-9-1) is connected to the bottom of the guide column (3-3), and the lower end extends into the inner cavity of the truncated cone scroll spring (3-1); the lower end of the damping connecting rod (3-9-1) and the damping disc (3-9-2) are immersed in the damping fluid (3-11) together, providing a damping effect of the vibration isolation device; the damping fluid (3-11) is loaded in the inner sleeve (3-5) and is sealed by installing a damping seal (3-10) between the inner sleeve (3-5) and the guide column (3-3).

2. A bionic claw type variable stiffness vibration isolation device for track vibration reduction according to claim 1, characterized in that: The toe-like linkage mechanism (3-2) is composed of two rods of different lengths and a high-strength telescopic spring (3-2-2), which respectively simulate two phalanges and muscles around the phalangeal joints and have a stiffness adjustment function; the two rods of different lengths are a first rod (3-2-1) and a second rod (3-2-3); one end of the first rod (3-2-1) is hinged to a slider (3-14) outside the inner sleeve (3-5); the slider (3-14) is connected to an annular limit stop (3-8) at the bottom edge of the top cover (3-7); the other end of the first rod (3-2-1) is connected to one end of the telescopic spring (3-2-2); the other end of the telescopic spring (3-2-2) is connected to the second rod (3-2-3); one end of the second rod (3-2-3) is hinged to the first rod (3-2-1), and the other end is mounted on the base (3-12) via a hinge support.

3. A bionic claw type variable stiffness vibration isolation device for track vibration reduction according to claim 2, characterized in that: Both ends of the telescopic spring (3-2-2) are fixed between the first rod (3-2-1) and the second rod (3-2-3) via draw hooks.

4. A bionic claw type variable stiffness vibration isolation device for track vibration reduction according to claim 2, characterized in that: It also includes a plurality of directional guide rails (3-6) vertically arranged outside the inner sleeve (3-5), adapted to the position of the toe-like linkage mechanism (3-2), and used to orient a slider (3-14) hinged at the end of a first rod (3-2-1) of the toe-like linkage mechanism (3-2), so that the toe-like linkage mechanism (3-2) moves in a vertical direction.

5. The bionic claw type variable stiffness vibration isolation device for track vibration reduction according to claim 2, characterized in that: An inner sleeve (3-5) mounted on the upper portion of the base (3-12) divides the base (3-12) into an outer ring portion and an inner circle portion occupied by the inner sleeve (3-5). The outer ring portion of the base is provided with a plurality of equidistant mounting holes (3-13) along a radial direction. A hinge support connected to the end of the second rod (3-2-3) of the toe-like linkage mechanism (3-2) is mounted on the base (3-12) via the mounting holes (3-13) to adjust the movement posture of the toe-like linkage mechanism (3-2).

6. A vibration reduction track system using the bionic claw-type variable stiffness vibration isolation device for track vibration reduction according to any one of claims 1 to 5, characterized in that: It comprises a basic roadbed (1), a track plate (2), rails (8), fasteners (9), and a plurality of vibration isolation components arranged inside the track plate (2); The steel rail (8) is arranged on the track plate (2) via a fastener (9); The vibration isolation assembly comprises an outer sleeve (4) cast in the track plate (2) and a bionic claw-type variable stiffness vibration isolation device (3) installed in the outer sleeve (4); the vibration isolation assembly is symmetrically arranged on both sides of the track plate (2) along the center line in the transverse direction of the track plate (2) and is evenly spaced along the length direction of the track plate (2); The vibration isolation assembly lifts the track plate (2) and floats it on the basic roadbed (1).

7. The vibration-damping track system according to claim 6, wherein: The top cover (3-7) of the bionic claw-type variable stiffness vibration isolation device lifts the track plate (2) through the internal support structure of the outer sleeve (4) and floats it on the basic roadbed (1); a gasket (5) for adjusting the height of the track plate is installed between the internal support structure of the outer sleeve (4) and the top cover (3-7); a moving range is left between the top cover and the top end of the inner sleeve, and the moving range is ensured to be smaller than the lifting distance of the track plate, so as to limit the maximum safe displacement of the vibration-damping track; A buckle (6) is welded on the outer wall of the outer sleeve (4) for being cast into the track plate (2) for fixation; The base (3-12) of the bionic claw-type variable stiffness vibration isolation device is fixed to the surface of the foundation roadbed (1) below the outer sleeve (4).

8. The vibration-damping track system according to claim 6, wherein: The vibration isolation assembly further comprises an insulating cover plate (7) which is arranged above the outer sleeve (4).

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