A vibration isolation track based on multiple negative stiffness mechanisms

Abstract

The present invention relates to the field of track vibration reduction technology, and in particular to a vibration isolation track based on multiple negative stiffness mechanisms, comprising a floating plate ballast and a railway track arranged on the top surface of the ballast; two symmetrical vertical stiffness variable vibration isolation supports are arranged at the bottom of the floating plate ballast; the vertical stiffness variable vibration isolation supports include an outer sleeve, an inner sleeve with a clamp, a butterfly spring, a steel spring and an axle rod; a mobile negative stiffness hinge mechanism is arranged at the center of the bottom of the ballast; the mobile negative stiffness hinge mechanism is composed of multiple connecting rods hinged to each other through multiple hinge points; elastic buffer components are symmetrically arranged on the sides of the ballast; the elastic buffer components are arranged between the ballast and the inner wall of the tunnel; the elastic buffer components include an inclined pre-bent steel plate, an inclined pre-tensioned steel spring and a horizontal pre-stressed steel spring, so that the ballast as a whole will have a larger negative stiffness effect, and then the overall natural frequency of the system is reduced, thereby providing a very obvious vibration isolation effect.

Description

Technical Field

[0001] The invention relates to the technical field of track vibration reduction, in particular to a vibration isolation track based on multiple negative stiffness mechanisms. Background Art

[0002] TOD mode (Transit-Oriented Development, referring to a development mode oriented towards public transportation) has gradually become the core direction of urban construction and development. The characteristics of this development mode are highly dense buildings, highly complex functions and highly three-dimensional transportation. One of the key points of the development of TOD mode is the development of subway transportation. As the scale of the development of TOD mode gradually increases, the vibration generated by the subway has brought about a negative impact on people's work and life that cannot be ignored. At present, the scheme adopted for subway vibration is mostly the steel spring floating plate roadbed vibration isolation scheme, which has a certain degree of effect on reducing subway vibration. In order for the steel spring to produce a more ideal vibration isolation effect, its own vertical stiffness design value needs to be smaller, which will lead to a larger vertical deformation range of the steel spring when bearing. However, due to the height limit of the subway tunnel, the height of the floating plate should not be too high, so the vertical deformation design value of the steel spring should not be too large, resulting in the design value of the vertical stiffness of the steel spring itself should not be too small, which will greatly limit the vibration isolation effect of the steel spring, and the energy dissipation capacity of the steel spring itself is relatively weak, so the above-mentioned vibration isolation scheme has obvious limitations in reducing subway vibration.

[0003] In summary, in the existing subway vibration isolation schemes, there is an obvious contradiction between the demand for bearing capacity and the demand for effective vibration isolation and energy dissipation, which greatly restricts the development of subway vibration isolation technology, and further restricts the further development of subway transportation and even the TOD model. Summary of the invention

[0004] The purpose of the present application is to provide a vibration isolation track based on multiple negative stiffness mechanisms, aiming to solve the problems in the prior art.

[0005] The embodiment of the present application provides a vibration isolation track based on multiple negative stiffness mechanisms, including a floating plate ballast and a railway track arranged on the top surface of the ballast; two symmetrical vertical stiffness variable vibration isolation supports are arranged at the bottom of the floating plate ballast; the vertical stiffness variable vibration isolation support includes an outer sleeve, an inner sleeve with a clamp, a butterfly spring, a steel spring and an axle rod; a mobile negative stiffness hinge mechanism is arranged at the center of the bottom of the ballast; the mobile negative stiffness hinge mechanism includes a hinge point, a connecting rod, a horizontal slide rail and a horizontal spring; the mobile negative stiffness hinge mechanism is composed of multiple connecting rods hinged to each other through multiple hinge points; the two ends of the horizontal spring are fixedly connected to the connecting rod or the hinge point; elastic buffer components are symmetrically arranged on the side of the ballast; the elastic buffer components are arranged between the ballast and the inner wall of the tunnel; the elastic buffer components include an inclined pre-bent steel plate, an inclined pre-tensioned steel spring and a horizontal pre-compressed steel spring.

[0006] Furthermore, the steel spring is installed in an inner sleeve, the outer surface of the inner sleeve has an external thread, and the outer surface of the inner sleeve is provided with a nut matching the external thread; the butterfly spring is installed between the inner sleeve, the nut and the inner surface of the outer sleeve.

[0007] Furthermore, a cover plate and a bottom plate are provided on the upper and lower sides of the vertically variable stiffness vibration isolation support, respectively; the cover plate and the bottom plate are fixedly connected to the floating plate ballast and the foundation by bolts.

[0008] Furthermore, the mobile negative stiffness hinge mechanism is triangular in shape as a whole; the topmost hinge point of the mobile negative stiffness hinge mechanism is installed on the floating plate track bed; and the connecting rod can rotate around the hinge point.

[0009] Furthermore, the two outermost hinge points at the bottom of the motorized negative stiffness hinge mechanism are slidably mounted on a horizontal slide rail; the horizontal slide rail is fixedly connected to the foundation; and the hinge point on the inner side of the bottom of the motorized negative stiffness hinge mechanism is connected to the foundation.

[0010] Furthermore, two ends of the inclined pre-bent steel plate, the inclined pre-tensioned steel spring and the horizontal pre-stressed steel spring are respectively fixedly connected to the floating slab roadbed and the inner wall of the tunnel by embedding.

[0011] Furthermore, the butterfly spring, steel spring, horizontal spring, oblique pre-bent steel plate, oblique pre-tensioned steel spring and horizontal pre-stressed steel spring are all made of steel or other shape memory alloy materials.

[0012] The beneficial effects of the present invention are as follows: the butterfly spring in the vertical stiffness variable vibration isolation support adopted by the present invention will produce a rollover deformation and thus generate negative stiffness, the mobile negative stiffness hinge mechanism will also produce a negative stiffness effect in the vertical compression deformation, and at the same time, the inclined pre-bent steel plate, the inclined pre-tensioned steel spring and the horizontal pre-stressed steel spring will also produce negative stiffness effects respectively as the floating plate track bed descends. At this time, the track bed as a whole will have a large negative stiffness effect, and then the overall natural frequency of the system will be reduced, thereby providing a very obvious vibration isolation effect. At the same time, the butterfly spring can also provide a certain degree of energy dissipation effect in the process of deformation under load.

[0013] In addition, the shaft rod in the vertical stiffness variable vibration isolation support, the mobile negative stiffness hinge mechanism, the inclined pre-bent steel plate, the inclined pre-tensioned steel spring and the horizontal pre-stressed steel spring all have certain horizontal bearing and limiting capabilities. Therefore, when the subway train passes through a curve, the floating slab roadbed has good horizontal stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0015] Figure 2 It is a structural schematic diagram of a vertical stiffness variable vibration isolation support.

[0016] Figure 3 Schematic diagram of the structure of the mobile negative stiffness hinge mechanism.

[0017] Figure 4 Schematic diagram of the buffer component structure.

[0018] Figure 5 It is a working schematic diagram of the present invention when it is subjected to vertical pressure.

[0019] Figure 6 This is a schematic diagram of the working state of the variable vertical stiffness vibration isolation bearing when it is subjected to vertical compression.

[0020] Figure 7 This is a schematic diagram of the working state of the mobile negative stiffness hinge mechanism when it is subjected to vertical pressure.

[0021] Figure 8 This is a schematic diagram of the working state of the elastic buffer component when it is subjected to vertical pressure.

[0022] In the figure:

[0023] 1. Floating slab ballast; 2. Railway track; 3. Inner wall of tunnel; 4. Mobile negative stiffness hinge mechanism; 41. Hinge point; 42. Connecting rod; 43. Horizontal slide rail; 44. Horizontal spring; 5. Oblique pre-bent steel plate; 6. Foundation; 7. Horizontal pre-stressed steel spring; 8. Oblique pre-tensioned steel spring; 9. Vertical stiffness variable vibration isolation bearing; 91. Cover plate; 92. Bottom plate; 93. Outer sleeve; 94. Inner sleeve with clamp; 95. Nut; 96. Butterfly spring; 97. Steel spring; 98. Shaft rod. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] like Figure 1-4 The vibration isolation track based on multiple negative stiffness mechanisms shown in the figure comprises a floating plate ballast bed 1 and a railway track 2 arranged on the top surface of the ballast bed; two symmetrical vertical stiffness variable vibration isolation supports 9 are arranged at the bottom of the floating plate ballast bed 1; the vertical stiffness variable vibration isolation supports 9 comprise an outer sleeve 93, an inner sleeve 94 with a clamping mouth, a butterfly spring 96, a steel spring 97 and a shaft 98; a mobile negative stiffness hinge mechanism 4 is arranged at the center of the bottom of the ballast bed; the mobile negative stiffness hinge mechanism 4 comprises a hinge point 4 1. Connecting rods 42, horizontal slide rails 43 and horizontal springs 44; the motorized negative stiffness hinge mechanism 4 is composed of multiple connecting rods 42 hinged to each other through multiple hinge points 41; both ends of the horizontal spring 44 are fixedly connected to the connecting rods 42 or the hinge points 41; elastic buffer components are symmetrically arranged on the sides of the ballast 1; the elastic buffer components are arranged between the ballast 1 and the inner wall 3 of the tunnel; the elastic buffer components include an inclined pre-bent steel plate 5, an inclined pre-tensioned steel spring 8 and a horizontal pre-stressed steel spring 7.

[0026] like Figure 2As shown, the steel spring 97 is installed in the inner sleeve 94, and the center of the steel spring 97 is provided with a shaft 98. The outer sleeve 93 is two sleeves that are slidably connected. The outer surface of the inner sleeve 94 has an external thread, and the outer surface of the inner sleeve 94 is provided with a nut 95 that matches the external thread; the butterfly spring 96 is installed between the inner sleeve 94, the nut 95 and the inner surface of the outer sleeve 93; nuts 95 are provided on the upper and lower sides of the butterfly spring 96, and the outer side and inner side of the butterfly spring 96 are connected with the inner surface of the outer sleeve and the outer surface of the inner sleeve. When the support is subjected to downward pressure, the outer sleeve 93 slides and the butterfly spring 96 flips and deforms. When the vertical stiffness variable vibration isolation support 9 only bears the deadweight load of the floating plate track bed 1, the butterfly spring 96 and the steel spring 97 in the vertical stiffness variable vibration isolation support 9 can provide a certain bearing capacity.

[0027] The vertically variable stiffness vibration isolation support 9 is provided with a cover plate 91 and a bottom plate 92 on the upper and lower sides respectively; the cover plate 91 and the bottom plate 92 are fixedly connected to the floating plate ballast 1 and the foundation 6 by bolts.

[0028] The mobile negative stiffness hinge mechanism 4 is triangular in shape as a whole; the topmost hinge point 41 of the mobile negative stiffness hinge mechanism 4 is installed on the floating slab track bed 1; and the connecting rod 42 can rotate around the hinge point 41.

[0029] The two outermost hinge points 41 at the bottom of the mobile negative stiffness hinge mechanism 4 are slidably mounted on the horizontal slide rail 43; the horizontal slide rail 43 is fixedly connected to the foundation 6; the hinge point 41 at the inner side of the bottom of the mobile negative stiffness hinge mechanism 4 is connected to the foundation 6. When the mobile negative stiffness hinge mechanism 4 only bears the deadweight load of the floating slab track bed 1, the mobile negative stiffness hinge mechanism 4 provides a certain bearing capacity through the coordinated action of the hinge point 41, the connecting rod 42 and the horizontal spring 44.

[0030] The two ends of the oblique pre-bent steel plate 5, the oblique pre-tensioned steel spring 8 and the horizontal pre-stressed steel spring 7 are respectively connected to the floating plate ballast 1 and the tunnel inner wall 3 by embedding and fixing. Figure 4 It is the initial state of each structure of the elastic component when there is no downward pressure.

[0031] The butterfly spring 96, steel spring 97, horizontal spring 44, oblique pre-bent steel plate 5, oblique pre-tensioned steel spring 8 and horizontal pre-stressed steel spring 7 are all made of steel or other shape memory alloy materials.

[0032] like Figure 5 As shown, when the floating slab roadbed 1 is subjected to the load of the subway, the floating slab roadbed 1 will move downward as a whole.

[0033] like Figure 6As shown, at this time, the butterfly spring 96 in the vertical stiffness variable vibration isolation support 9 will produce a flip deformation, providing a certain negative stiffness effect, thereby reducing the natural frequency of the system and improving the vibration isolation effect of the system. At the same time, the internal mutual friction of the butterfly spring 96 during the deformation process will produce a certain energy consumption effect, and the steel spring 97 can also provide a certain vibration isolation effect.

[0034] The structure of the mobile negative stiffness hinge mechanism 4 changes as follows Figure 7 As shown, the top hinge point 41 of the motorized negative stiffness hinge mechanism 4 moves downward, driving the connecting rods 42 on both sides to move axially while rotating and driving the two middle hinge points 41 to move axially, and the two middle hinge points 41 will drive the outermost connecting rods 42 connected below to move axially while rotating. At this time, the bottom end of the outermost connecting rod 42 will move horizontally outward along the horizontal slide rail 43 along the hinge point 41 at the bottom. At this time, the entire motorized negative stiffness hinge mechanism 4 is in a compressed state vertically and in an outward stretched state horizontally. During this process, all horizontal springs 44 are in a tensile state. Therefore, the motorized negative stiffness hinge mechanism 4 will produce a negative stiffness effect, thereby reducing the natural frequency of the system and improving the vibration isolation effect of the system.

[0035] At this time, the structural changes of the elastic buffer components are as follows Figure 8 As shown, the inclined pre-bent steel plate 5 will rotate to the horizontal direction and will be further bent at the same time, the horizontal pre-stressed steel spring 7 will rotate to tilt downward and will be stretched to a certain extent (the horizontal pre-stressed steel spring 7 is still in a compressed state at this time), and the inclined pre-tensioned steel spring 8 will rotate to the horizontal direction and will be compressed to a certain extent (the inclined pre-tensioned steel spring 8 is still in a tensile state). All three of the above will produce a negative stiffness effect, thereby reducing the natural frequency of the system and improving the vibration isolation effect of the system.

[0036] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A vibration isolation track based on multiple negative stiffness mechanisms, characterized in that: It comprises a floating plate ballast and a railway track arranged on the top surface of the ballast; two symmetrical vertical stiffness variable vibration isolation supports are arranged at the bottom of the floating plate ballast; the vertical stiffness variable vibration isolation supports comprise an outer sleeve, an inner sleeve with a clamping mouth, a butterfly spring, a steel spring and an axle rod; a mobile negative stiffness hinge mechanism is arranged at the center of the bottom of the floating plate ballast; the mobile negative stiffness hinge mechanism comprises a hinge point, a connecting rod, a horizontal slide rail and a horizontal spring; the mobile negative stiffness hinge mechanism is composed of a plurality of connecting rods hinged to each other through a plurality of hinge points; the mobile negative stiffness hinge mechanism is triangular in shape as a whole; the mobile negative stiffness hinge mechanism The top hinge point of the chain mechanism is installed on the floating plate ballast; the connecting rod can rotate around the hinge point; the two outermost hinge points at the bottom of the mobile negative stiffness hinge mechanism are slidably installed on the horizontal slide rail; the horizontal slide rail is fixedly connected to the foundation; the hinge point on the inner side of the bottom of the mobile negative stiffness hinge mechanism is connected to the foundation; the two ends of the horizontal spring are fixedly connected to the connecting rod or the hinge point; the side of the floating plate ballast is symmetrically provided with elastic buffer components; the elastic buffer components are arranged between the ballast and the inner wall of the tunnel; the elastic buffer components include an inclined pre-bent steel plate, an inclined pre-tensioned steel spring and a horizontal pre-stressed steel spring.

2. The vibration isolation track based on multiple negative stiffness mechanisms according to claim 1, characterized in that: The steel spring is installed in the inner sleeve, the outer surface of the inner sleeve has an external thread, and the outer surface of the inner sleeve is provided with a nut matching the external thread; the butterfly spring is installed between the inner sleeve, the nut and the inner surface of the outer sleeve.

3. The vibration isolation track based on multiple negative stiffness mechanisms according to claim 2, characterized in that: The upper and lower sides of the vertically variable stiffness vibration isolation support are respectively provided with a cover plate and a bottom plate; the cover plate and the bottom plate are fixedly connected to the floating plate ballast and the foundation by bolts.

4. The vibration isolation track based on multiple negative stiffness mechanisms according to claim 1, characterized in that: The two ends of the inclined pre-bent steel plate, the inclined pre-tensioned steel spring and the horizontal pre-stressed steel spring are respectively connected to the floating plate ballast and the inner wall of the tunnel by being embedded and fixed.

5. The vibration isolation track based on multiple negative stiffness mechanisms according to any one of claims 1 to 4, characterized in that: The butterfly spring, steel spring, horizontal spring, oblique pre-bent steel plate, oblique pre-tensioned steel spring and horizontal pre-stressed steel spring are all made of steel or other shape memory alloy materials.

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