CN207485957U - A kind of cam bawl negative stiffness structure low frequency vibration isolation device - Google Patents
A kind of cam bawl negative stiffness structure low frequency vibration isolation device Download PDFInfo
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Abstract
The utility model is related to a kind of cam bawl negative stiffness structure low frequency vibration isolation devices.The low frequency vibration isolation device applies positive and negative Stiffness principle, and using positive stiffness elements and negative stiffness element in parallel, protection is provided with reference to the damping unit suppression system resonance of installation and for too drastic situation；Positive stiffness and negative stiffness regulating device realizes effective and accurate adjusting of positive stiffness and negative stiffness range, to meet different bearer quality and vibration isolation requirement, efficiently solves the problems such as existing low frequency vibration isolation device installation is inconvenient, complicated, adaptability for working condition is poor.
Description
Technical Field
The utility model relates to a damping vibration isolation technical field, concretely relates to cam roller negative stiffness structure low frequency isolator.
Background
At present, urban rail transit is rapidly developed as one of the most effective ways to relieve urban traffic pressure. However, the environmental vibrations induced by it are becoming increasingly severe: the impact generated by the gravity loading of the rail when the train operates can cause the vibration of the rail structure, and the vibration is transmitted to buildings, instruments and equipment and the like along sleepers, railway beds, foundations and the like, thereby causing serious environmental vibration. Among these environmental vibrations, low-frequency vibration is a difficult point for environmental vibration control.
On the other hand, as the size and weight of power machines increase, the flexibility of parts increases, and the problem of low-frequency vibration caused by flexible bodies becomes more and more serious. The traditional linear rigidity vibration isolation technology is only used in(omega and omega)nExcitation frequency and natural frequency of the system respectively) has a vibration isolation effect; the flexibility of system parts is increased, so that low-frequency vibration resistance is needed, the natural frequency of a large-scale machine under a high-bearing condition is always kept unchanged, the problems of low-frequency vibration resistance and poor low-frequency vibration isolation effect caused by high natural frequency of the system are solved, and even excessive static deformation and instability are caused in severe cases. Therefore, the problem of excessive static deformation of the traditional steel spring vibration isolator can occur when the traditional steel spring vibration isolator isolates low-frequency vibration of a track, and the traditional steel spring vibration isolator faces a great challenge that the stability and the low-frequency vibration isolation capability cannot be considered at the same time.
In order to improve the low-frequency vibration isolation capability, the natural frequency of the system must be reduced, which in turn will result in the reduction of the stiffness of the system, and inevitably will cause the load-bearing capability of the system to be reduced. Therefore, the traditional linear vibration isolator faces the contradiction between low rigidity and large static deformation when isolating low-frequency and ultralow-frequency vibration. In order to reduce the harm of low-frequency vibration in engineering, various vibration damping methods are researched, and various corresponding vibration control devices are produced, and the related documents are as follows:
in the vibration and impact publication 2011, volume 30, No. 1, of 'design of a novel ultralow-frequency nonlinear passive vibration isolation system', the ultralow-frequency passive vibration isolation system with nonlinear rigidity is designed according to a rigidity expression of positive and negative rigidity parallel vibration isolation and a zero rigidity condition at a balance position. However, the hinged connecting rod of the positive and negative stiffness parallel mechanism of the scheme can only isolate excitation in a vertically downward direction, and has the defects of negative stiffness structural design and single and inflexible realization.
Chinese patent publication No. CN 101871505 a discloses a three-translation vibration and impact isolation platform with parallel positive and negative stiffness, which has the characteristics of large bearing capacity, high stability, small volume, low natural frequency, controllable damping, low manufacturing and maintenance costs, and the like. However, the adaptability and flexibility are poor.
Chinese patent publication No. CN 202520846U discloses a low-frequency vibration isolator using four inclined linear springs and a vertical linear spring to provide restoring force, and the stiffness of the system at the static equilibrium position is zero by reasonably designing the stiffness coefficients and geometric parameters of the vertical spring and the inclined spring, so as to achieve the purpose of small dynamic stiffness of the system. However, the existing ultra-low frequency vibration isolation system has complex requirements, complex system composition and variable states, and the low frequency vibration isolation system expanded based on the principle with a single structure is too simple in structure and weak in adaptability, flexibility and expandability.
The Chinese patent document with the publication number of CN 202520848U discloses an ultralow frequency vibration isolator based on parallel connection of positive and negative stiffness springs, which comprises guide posts, a sleeve cover, a slide block, a negative stiffness spring, a lower cover, a guide seat, balls and a main spring, and the vibration isolator can realize the characteristics of high static stiffness and low dynamic stiffness, realize zero-hertz ultralow frequency vibration isolation and has adjustable vibration isolation performance; rolling friction is realized by adopting the balls, so that the friction resistance is reduced; the vibration isolation and vibration damping device can be used as a component, and is suitable for an environment subjected to vibration excitation, particularly an environment subjected to low-frequency vibration excitation, such as vehicle seats, suspensions, precise instruments for vibration isolation, vibration damping and shock resistance and the like. However, the frequency range of the negative stiffness characteristic of the vibration isolator depends on the depth of a mounting hole of a negative stiffness spring arranged at the sleeve cover, the negative stiffness cannot be freely adjusted, the vibration isolator has great limitation, and only low-frequency vibration of specific frequency or frequency band can be isolated.
Chinese patent publication No. CN 203641365U discloses a quasi-zero stiffness vibration isolator, which uses four horizontal springs and a vertical spring to provide restoring force, and uses a roller-cam device to connect a horizontal moving device and a vertical moving device to form a non-linear geometric mechanism; the rigidity of the system at a static balance position is zero by designing the rigidity coefficients of the vertical spring and the horizontal spring and adjusting the compression amount of the horizontal spring, so that low-frequency or ultralow-frequency vibration isolation is realized.
Chinese patent publication No. CN 102678804B discloses a nonlinear ultra-low frequency vibration isolator composed of a negative stiffness sliding elastic beam and a positive stiffness spring, the utility model discloses the whole system has nearly dynamic quasi-zero stiffness characteristic, can realize the vibration isolation of ultra-low frequency and has anti-impact effect at the same time. However, the vibration isolator of the utility model has very strict requirements on the material characteristics and the installation accuracy of the sliding elastic beam in the actual engineering, and is not beneficial to the engineering popularization.
SUMMERY OF THE UTILITY MODEL
The utility model aims to provide a cam roller burden rigidity structure low frequency isolator to current low frequency isolator installation inconvenient, the structure is complicated, operating mode adaptability is poor scheduling problem. The low-frequency vibration isolator applies a positive and negative rigidity parallel principle, uses a positive rigidity element and a negative rigidity element which are connected in parallel, and combines an additionally arranged damping device to inhibit system resonance and provide protection against over-excitation; the positive and negative rigidity adjusting device realizes effective and accurate adjustment of positive and negative rigidity ranges to meet different bearing qualities and vibration isolation requirements.
In order to achieve the above object, the utility model provides a cam roller negative stiffness structure low frequency vibration isolator, the low frequency vibration isolator includes load-bearing device, negative stiffness spring connection cylindrical roller, plummer connection cam, vertical direction positive stiffness spring, positive stiffness spring positioning adjustment device, horizontal direction negative stiffness spring structure, negative stiffness spring positioning device, negative stiffness spring bottom plate fixing device, horizontal direction negative stiffness spring compression amount adjustment device, and bottom plate fixing support device; wherein,
the lower end of the center of the bearing device is connected with a bearing table connecting cam, negative stiffness springs are arranged on two sides of the bearing table connecting cam and connected with cylindrical rollers, a high-pair connection is arranged between the bearing table connecting cam and the negative stiffness spring and connected with the cylindrical rollers, and a vertical positive stiffness spring positioning and adjusting device are connected and installed below the bearing table connecting cam; the horizontal direction negative stiffness spring structure is connected with the negative stiffness spring positioning device and the negative stiffness spring bottom plate fixing device, and a horizontal direction negative stiffness spring compression amount adjusting device is installed outside the horizontal direction negative stiffness spring structure; the negative stiffness spring compression amount adjusting device, the negative stiffness spring bottom plate fixing device and the positive stiffness spring positioning adjusting device are all connected with the bottom plate fixing and supporting device.
Further, the carrying device can be a carrying table for carrying mass and being excited.
Furthermore, the vertical positive stiffness spring can be a vertical spring and can move in the vertical direction under the excitation action of the bearing table.
Furthermore, the positive stiffness spring positioning and adjusting device can be composed of a central shaft fixing and connecting block, a vertical spring central shaft, a vertical spring compression amount adjusting knob, a vertical spring end fixing and pressing plate, a vertical spring bottom fixing block and a vertical spring linear bearing; wherein,
center pin fixed connection piece is connected to plummer below, vertical spring center pin can be connected through the screw thread mode with center pin fixed connection piece, install vertical spring compression volume adjust knob on vertical spring center pin, be connected fixed vertical spring through vertical spring tip fixed pressing plate between vertical spring compression volume adjust knob and the vertical spring bottom fixed block, vertical spring center pin passes vertical spring inside on vertical spring axial direction, vertical spring realizes the direction through vertical spring center pin, pass through bolted connection between vertical spring tip fixed pressing plate and the vertical spring bottom fixed block, pass through bolted connection between vertical spring bottom fixed block and the vertical spring linear bearing. The linear bearing provides vertical orientation for the vertical spring center shaft.
Furthermore, the horizontal direction negative stiffness spring structure can be composed of a horizontal spring, a horizontal spring end connecting block and a horizontal spring end fixing pressing plate; wherein,
and the horizontal spring is connected between the two horizontal spring end connecting blocks, and the horizontal spring is fixedly connected with the horizontal spring end connecting blocks through the horizontal spring end fixing pressing plate.
Furthermore, the negative stiffness spring connecting cylindrical roller can be composed of a horizontal spring connecting cylindrical roller, a cylindrical roller hinge support block and a cylindrical roller hinge support block connecting rod; wherein,
the connecting rod of the cylindrical roller hinge support block is connected to one side, opposite to the connecting cam of the bearing table, of the horizontal spring end connecting block, the tail end of the connecting rod of the cylindrical roller hinge support block is sequentially connected with the cylindrical roller hinge support block and the horizontal spring connecting cylindrical roller, and the horizontal spring connecting cylindrical roller and the cylindrical roller hinge support block are connected and installed in a hinge mode.
The horizontal spring connecting cylindrical roller and the plummer connecting cam in the vertical direction can be pressed tightly through the pressing force generated by the pre-compression amount of the horizontal springs at two sides by high pair contact.
Furthermore, the negative stiffness spring positioning device can be composed of a horizontal spring positioning connecting plate and a horizontal spring linear slide rail; wherein,
and a horizontal spring positioning connecting plate is fixedly connected below the horizontal spring end connecting block, and a horizontal spring linear sliding rail is connected below the horizontal spring positioning connecting plate. The horizontal spring linear slide rail provides horizontal positioning guide for the horizontal spring.
Furthermore, the horizontal direction negative stiffness spring compression amount adjusting device can be composed of a horizontal spring compression amount adjusting knob and a horizontal spring adjusting knob fixing block; wherein,
the horizontal spring compression amount adjusting knob is connected with the horizontal spring adjusting knob fixing block, and the horizontal spring end connecting block adjusts the installation compression amount of the horizontal spring through the horizontal spring compression amount adjusting knob.
Further, the negative stiffness spring bottom plate fixing device can be a horizontal spring bottom plate connecting block. The horizontal spring adjusting knob fixing block and the horizontal spring linear slide rail are fixedly connected to the horizontal spring bottom plate connecting block through bolts.
Further, the bottom plate fixing and supporting device can be composed of a model bottom plate and a model foot pad. The model foot pad is fixed below the model bottom plate, so that the working condition adaptability of the vibration isolator is enhanced; two horizontal spring bottom plate connecting blocks and a vertical spring linear bearing are fixed above the model bottom plate in a bolt mode, and the two horizontal spring bottom plate connecting blocks are located on two sides of the vertical spring linear bearing.
Furthermore, a horizontally placed damper is connected between the two horizontal spring end connecting blocks on the two sides. In one embodiment, the damper is plural.
The utility model discloses a connection and installation of its each component of cam roller negative stiffness structure low frequency isolator with the connection and the installation of each component of cam roller negative stiffness structure low frequency isolator use the center pin place of the positive stiffness spring of vertical direction (vertical spring) and be central plane symmetric distribution with bottom plate fixed stay device vertically plane. The method specifically comprises the following steps:
a model foot pad is fixed below the model bottom plate, so that the working condition adaptability of the vibration isolator is enhanced; and a horizontal spring bottom plate connecting block and a vertical spring linear bearing are fixed above the model bottom plate in a bolt mode. And a horizontal spring linear slide rail is fixedly connected above the horizontal spring bottom plate connecting block through a bolt, and provides positioning guidance in the horizontal direction for the horizontal spring. The horizontal spring positioning connecting plates are connected above the two sliding rails, the horizontal spring end connecting blocks are fixed above the horizontal spring positioning connecting plates, the horizontal springs are connected between the two horizontal spring end connecting blocks, and the horizontal springs are fixedly connected with the horizontal spring end connecting blocks through the horizontal spring end fixing pressing plates. Furthermore, a horizontally disposed damper is connected between the two horizontal spring end connection blocks. The horizontal spring end connecting block adjusts the installation compression amount of the horizontal spring through a horizontal spring compression amount adjusting knob, the horizontal spring compression amount adjusting knob is connected with a horizontal spring adjusting knob fixing block, and the horizontal spring adjusting knob fixing block is fixed on the model base plate through bolt connection. The other side of the horizontal spring end connecting block is connected with a cylindrical roller hinge supporting block connecting rod, the tail end of the connecting rod is connected with a cylindrical roller hinge supporting block and a horizontal spring connection cylindrical roller, and the horizontal spring connection cylindrical roller and the cylindrical roller hinge supporting block are connected and installed in a hinge mode. The horizontal spring is connected with the cylindrical roller and is in high-pair contact with the plummer connecting cam in the vertical direction, and the cylindrical roller and the cam are pressed tightly through pressing force generated by the pre-compression amount of the horizontal spring. The plummer is connected the cam and is connected with the plummer through the bolt mode, center pin fixed connection piece is connected to the plummer below, vertical spring center pin passes through the screw thread mode with center pin fixed connection piece and is connected, install vertical spring compression volume adjust knob on vertical spring center pin, connect fixed vertical spring through vertical spring tip fixed pressing plate between vertical spring compression volume adjust knob and the vertical spring bottom fixed block, vertical spring realizes the direction through vertical spring center pin, pass through bolted connection between vertical spring tip fixed pressing plate and vertical spring bottom fixed block and the vertical spring linear bearing. The linear bearing provides vertical orientation for the vertical spring center shaft.
The utility model discloses cam roller burden rigidity structure low frequency isolator has following advantage:
1. the rigidity of the vibration isolator in the upper and lower ranges of a static balance position can be reduced by adjusting the positive and negative rigidity values, so that the vibration isolator has the characteristics of high static rigidity and low dynamic rigidity and can be applied to vibration isolation of automobile seats, ship decks and the like;
2. the positive stiffness element adjusting device, the vertical spring main body, the negative stiffness element device and the damping device are provided with the positioning devices, so that the whole structure keeps strict limiting motion, and the impact and other influences caused by system unbalance are reduced;
3. the bottom foot pad of the vibration isolator provides more use scenes for products;
4. the adjustment of the compression amount of the horizontal spring of the utility model is controlled by the adjustment knob of the compression amount of the horizontal spring at the end part of the horizontal spring, and the compression amount of the horizontal spring at both ends can be controlled to be consistent by the number of turns of the screw threads screwed in and out in the actual operation;
5. the utility model discloses a horizontal spring arranges the public horizontal slide rail of attenuator with the level, has effectively guaranteed the synchronism of the two motion, and in addition, the horizontal slide rail of this design has reserved certain sliding distance, can be applicable to different specification horizontal springs and attenuators, improves the suitability of global design.
6. The vertical spring of the utility model can select the spring specification meeting the working condition requirements according to different bearing conditions and vibration isolation requirements, and has better economical efficiency;
7. the number of the horizontal springs of the utility model can be adjusted according to different vibration isolation requirements and the relation between positive and negative stiffness;
8. the utility model discloses a attenuator model and quantity can change, can restrain the system resonance condition to protect the overload excitation condition, have the strong advantage of self-protection nature promptly.
Drawings
Fig. 1 is a structural block diagram of a system of the low-frequency vibration isolator with a cam roller negative stiffness structure according to the present invention;
fig. 2 is a schematic structural diagram of a low-frequency vibration isolator with a cam roller negative stiffness structure according to the present invention and embodiment 2;
fig. 3 is a schematic structural diagram of a negative stiffness structure in the low-frequency vibration isolator with a cam roller negative stiffness structure according to the present invention and embodiment 2;
fig. 4 is a schematic structural diagram of a low-frequency vibration isolator with a cam roller negative stiffness structure according to the present invention and embodiment 3;
fig. 5 is a stiffness characteristic curve of the low-frequency vibration isolator with a cam roller negative stiffness structure according to the present invention and in embodiment 3, under different initial horizontal spring compression amounts;
fig. 6 is a schematic structural diagram of a low-frequency vibration isolator with a cam roller negative stiffness structure according to the present invention and embodiment 4;
fig. 7 is a schematic diagram of an effective vibration isolation displacement interval of a low-frequency vibration isolator with a cam roller negative stiffness structure according to the present invention and in embodiment 4, under different initial static equilibrium positions;
fig. 8 is a schematic structural view of the low-frequency vibration isolator with a cam roller negative stiffness structure according to the present invention and embodiment 5;
fig. 9 is a horizontal damping force displacement curve of the low-frequency vibration isolator with the cam roller negative stiffness structure according to the present invention and embodiment 5.
Wherein the reference numerals are:
a is a bearing device, B is a negative stiffness spring connecting cylindrical roller, C is a bearing table connecting cam, D is a vertical positive stiffness spring, E is a positive stiffness spring positioning and adjusting device, F is a horizontal negative stiffness spring structure, G is a negative stiffness spring positioning device, H is a negative stiffness spring bottom plate fixing device, I is a horizontal negative stiffness spring compression amount adjusting device, and J is a bottom plate fixing and supporting device;
1 is the plummer, 2 is center pin fixed connection piece, 3 is plummer connection cam, 4 is horizontal spring connection cylinder roller, 5 is cylinder roller articulated supporting shoe, 6 is cylinder roller articulated supporting shoe connecting rod, 7 is horizontal spring end connection piece, 8 is horizontal spring, 9 is horizontal installation attenuator, 10 is horizontal spring end fixed clamp plate, 11 is horizontal spring compression regulating knob, 12 is horizontal spring regulating knob fixed block, 13 is vertical spring center pin, 14 is vertical spring compression regulating knob, 15 is vertical spring end fixed clamp plate, 16 is vertical spring, 17 is vertical spring bottom fixed block, 18 is vertical spring linear bearing, 19 is horizontal spring location connecting plate, 20 is horizontal spring linear slide rail, 21 is horizontal spring bottom plate connecting block, 22 is the model bottom plate, 23 is the model pad foot.
Detailed Description
The present invention will be described with reference to the accompanying drawings. It should be understood that the following examples are illustrative of the present invention, but are not intended to limit the scope of the present invention.
Example 1
As shown in fig. 1, the invention is a structural block diagram of a system of a low-frequency vibration isolator with a negative stiffness structure of a cam roller. The connection relation of each component module is as follows:
the lower end of the center of the bearing device A is connected with a bearing table connecting cam C, negative stiffness springs are arranged on two sides of the bearing table connecting cam C and connected with cylindrical rollers B, the cam C and the cylindrical rollers B are connected through a high pair, and a vertical positive stiffness spring D and a positive stiffness spring positioning and adjusting device E are connected and installed below the cam C; the negative stiffness spring connecting cylindrical roller B is connected with a horizontal negative stiffness spring structure F, the negative stiffness spring structure F is connected with a negative stiffness spring positioning device G and a negative stiffness spring bottom plate fixing device H, and a horizontal negative stiffness spring compression amount adjusting device I is installed on the outer side of the horizontal negative stiffness spring structure F; the negative stiffness spring compression amount adjusting device I, the negative stiffness spring bottom plate fixing device H and the positive stiffness spring positioning adjusting device E are all connected with a bottom plate fixing and supporting device J, and the bottom plate fixing and supporting device J is fixed on a plane foundation.
Example 2
As shown in fig. 2-5; wherein, fig. 2 is a schematic structural diagram of the low-frequency vibration isolator with the cam roller negative stiffness structure according to the present invention; fig. 3 is a schematic structural diagram of a negative stiffness structure in the low-frequency vibration isolator with a cam roller negative stiffness structure according to the present invention; fig. 4 is a schematic structural diagram of a horizontal spring bottom plate connecting block in the low-frequency vibration isolator with the cam roller negative stiffness structure of the invention; fig. 5 is a schematic structural diagram of a bottom plate of a model in the low-frequency vibration isolator with a cam roller negative stiffness structure according to the present invention.
Referring to fig. 2 and 3, the low-frequency vibration isolator with the cam roller negative stiffness structure provided in the embodiment includes a model base plate 22, and a model foot pad 23 is fixed below the model base plate 22, so that the working condition adaptability of the vibration isolator is enhanced; two horizontal spring bottom plate connecting blocks 21 and a vertical spring linear bearing 18 are fixed above the model bottom plate 22 in a bolt mode, and the two horizontal spring bottom plate connecting blocks 21 are located on two sides of the vertical spring linear bearing 18. Two horizontal spring linear sliding rails 20 are fixedly connected above the horizontal spring bottom plate connecting block 21 on one side through bolts, and the horizontal spring linear sliding rails 20 provide positioning guide in the horizontal direction for the horizontal spring 8. The upper parts of the two linear slide rails 20 are respectively connected with a horizontal spring positioning connecting plate 19, a horizontal spring end connecting block 7 is fixed above the horizontal spring positioning connecting plate 19, a horizontal spring 8 is connected between the two horizontal spring end connecting blocks 7, and the horizontal spring 8 and the horizontal spring end connecting block 7 are fixedly connected through a horizontal spring end fixing pressing plate 10. Furthermore, a horizontally disposed damper 9 is connected between the two horizontal spring end connection blocks 7 on one side. Horizontal spring end connecting block 7 adjusts the installation compression of horizontal spring 8 through horizontal spring compression adjusting knob 11, and horizontal spring compression adjusting knob 11 is connected with horizontal spring adjusting knob fixed block 12, and horizontal spring adjusting knob fixed block 12 passes through bolted connection and fixes to horizontal spring bottom plate connecting block 21. The other side of the horizontal spring end connecting block 7 is connected with a cylindrical roller hinge support block connecting rod 6, the tail end of the connecting rod 6 is connected with a cylindrical roller hinge support block 5 and a horizontal spring connection cylindrical roller 4, and the horizontal spring connection cylindrical roller 4 and the cylindrical roller hinge support block 5 are connected and installed in a hinge mode. The horizontal spring connecting cylindrical roller 4 is in high-pair contact with the plummer connecting cam 3 in the vertical direction, and the cylindrical roller 4 and the cam 3 are pressed tightly by pressing force generated by the pre-compression amount of the horizontal springs 8 at two sides. The plummer is connected cam 3 and is connected with plummer 1 through the bolt mode, center pin fixed connection piece 2 is connected to plummer 1 below, vertical spring center pin 13 is connected through the screw thread mode with center pin fixed connection piece 2, install vertical spring compression volume adjust knob 14 on vertical spring center pin 13, connect fixed vertical spring 16 through vertical spring tip fixed pressing plate 15 between vertical spring compression volume adjust knob 14 and the vertical spring bottom fixed block 17, vertical spring 16 realizes the direction through vertical spring center pin 13, pass through bolted connection between vertical spring tip fixed pressing plate 15 and the vertical spring bottom fixed block 17, pass through bolted connection between vertical spring bottom fixed block 17 and the vertical spring linear bearing 18. The linear bearing 18 provides vertical orientation for the vertical spring center shaft 13.
The working process and the principle of the low-frequency vibration isolator with the cam roller negative stiffness structure in the embodiment are as follows:
under the excitation action of the bearing platform 1, the vertical spring 16 connected to the bearing platform 1 moves, meanwhile, the bearing platform connecting cam 3 and the horizontal spring connecting cylindrical roller 4 move relatively, the horizontal spring 8 and the horizontal damper 9 move and move linearly in the horizontal direction strictly, and therefore the integral positive and negative stiffness parallel device is formed, nonlinear damping is generated, and the vibration isolator generates a low-frequency vibration isolation effect. In the embodiment, the positive and negative stiffness elements are connected in parallel, and the stiffness values of all types of springs and the radiuses of the horizontal spring connecting cylindrical roller 4 and the plummer connecting cam 3 are selected, so that the quasi-zero stiffness of the vibration isolator at the static balance position is realized.
The horizontal spring 8 is connected with the horizontal spring end connecting block 7 through the end fixing pressing plate 10, the horizontal damper 9 is connected with the horizontal spring end connecting block 7 in a bolt connection mode, meanwhile, the bottom of the horizontal spring end connecting block 7 is connected with the horizontal spring linear sliding rail 20 through the horizontal spring positioning connecting plate 19, and the horizontal spring 8 and the horizontal damper 9 are strictly guaranteed to move in the horizontal direction. The vertical spring center shaft 13 provides guidance for the vertical spring 16, and the vertical spring center shaft 13 is positioned in the vertical direction through the vertical spring linear bearing 18, so that the vertical spring 16 moves strictly in the vertical direction.
Example 3
Fig. 4 is a schematic structural diagram of the low-frequency vibration isolator with the cam roller negative stiffness structure according to the embodiment. The difference from embodiment 2 is that the horizontal spring compression amount adjusting knob 11 is adjusted. The adjustment knob for adjusting the compression amount of the horizontal spring can realize the adjustment of the compression amount of the horizontal spring in the initial state, change the negative stiffness value of the vibration isolator and enhance the working condition adaptability of the vibration isolator.
Fig. 5 is the stiffness characteristic curve of the low-frequency vibration isolator with the cam roller negative stiffness structure under the condition of different initial horizontal spring compression amounts. The parameter δ in the graph is the ratio of the horizontal spring compression to the sum of the cam and cylindrical roller radii; x represents the displacement of the initial state; k represents the stiffness of the overall structure. From the curve, the stiffness characteristic curve moves downwards when the compression amount of the horizontal spring is larger, namely, the negative stiffness value of the negative stiffness structure of the vibration isolator is increased along with the increase of the compression amount of the horizontal spring.
Example 4
Fig. 6 is a schematic structural diagram of the low-frequency vibration isolator with the cam roller negative stiffness structure according to the embodiment. Fig. 7 is a schematic diagram showing an effective vibration isolation displacement interval of the low-frequency vibration isolator with the cam roller negative stiffness structure in the example under the condition of different initial static balance positions.
The difference between the embodiment and the embodiment 3 is that the initial position of the vertical spring of the vibration isolator in the initial state is adjusted by adjusting the vertical spring adjusting device, so that the vibration isolation displacement interval of the vibration isolator is changed. As can be seen from fig. 7, when the initial static balance position of the vibration isolator is changed and the centers of the cam at the static balance position and the cylindrical roller are on the same straight line, the vibration isolator has the maximum effective vibration isolation displacement interval, and the mechanical characteristics of the vibration isolator are symmetrical, so that the overall stability of the vibration isolator can be improved.
Example 5
Fig. 8 is a schematic structural diagram of the low-frequency vibration isolator with the cam roller negative stiffness structure in the embodiment. Fig. 9 shows a horizontal damping force displacement curve of the low-frequency vibration isolator with the cam roller negative stiffness structure in the embodiment.
This embodiment is different from embodiment 4 in that the installation of the horizontal damper, which provides a nonlinear damping force to the system, is changed. The horizontal damping force for the vibration isolator is:
wherein c is the damping coefficient of the damper, r1Is the cam radius, r2Is the cylindrical roller radius and x is the vertical displacement.
The corresponding curve is shown in fig. 9. It can be seen from the graph that the larger the damping force is generated correspondingly with the increase of the damping coefficient, and the larger the change rate of the damping force with the displacement is. The damper installation with different damping coefficients can be selected for different working conditions.
Although the invention has been described in detail with respect to the general description and the specific embodiments, it will be apparent to those skilled in the art that modifications and improvements can be made based on the invention. Therefore, such modifications and improvements are intended to be within the scope of the invention as claimed.
Claims (10)
1. The low-frequency vibration isolator is characterized by comprising a bearing device, a negative stiffness spring connecting cylindrical roller, a bearing platform connecting cam, a vertical positive stiffness spring, a positive stiffness spring positioning and adjusting device, a horizontal negative stiffness spring structure, a negative stiffness spring positioning device, a negative stiffness spring bottom plate fixing device, a horizontal negative stiffness spring compression amount adjusting device and a bottom plate fixing and supporting device, wherein the negative stiffness spring connecting cylindrical roller is fixedly connected with the bearing platform; wherein,
the lower end of the center of the bearing device is connected with a bearing table connecting cam, negative stiffness springs are arranged on two sides of the bearing table connecting cam and connected with cylindrical rollers, a high-pair connection is arranged between the bearing table connecting cam and the negative stiffness spring and connected with the cylindrical rollers, and a vertical positive stiffness spring positioning and adjusting device are connected and installed below the bearing table connecting cam; the horizontal direction negative stiffness spring structure is connected with the negative stiffness spring positioning device and the negative stiffness spring bottom plate fixing device, and a horizontal direction negative stiffness spring compression amount adjusting device is installed outside the horizontal direction negative stiffness spring structure; the negative stiffness spring compression amount adjusting device, the negative stiffness spring bottom plate fixing device and the positive stiffness spring positioning adjusting device are all connected with the bottom plate fixing and supporting device.
2. The cam roller negative stiffness structural low frequency vibration isolator of claim 1, wherein the positive stiffness spring positioning adjustment device is composed of a central shaft fixed connection block, a vertical spring central shaft, a vertical spring compression amount adjustment knob, a vertical spring end fixed pressing plate, a vertical spring bottom fixed block and a vertical spring linear bearing; wherein,
center pin fixed connection piece is connected to plummer below, vertical spring center pin passes through the screw thread mode with center pin fixed connection piece and is connected, install vertical spring compression volume adjust knob on vertical spring center pin, connect fixed vertical spring through vertical spring tip fixed pressing plate between vertical spring compression volume adjust knob and the vertical spring bottom fixed block, vertical spring center pin passes vertical spring in vertical spring axial direction inside, pass through bolted connection between vertical spring tip fixed pressing plate and the vertical spring bottom fixed block, pass through bolted connection between vertical spring bottom fixed block and the vertical spring linear bearing.
3. The cam roller negative stiffness structural low frequency vibration isolator of claim 2, wherein the horizontal direction negative stiffness spring structure is composed of a horizontal spring, a horizontal spring end connecting block, and a horizontal spring end fixing pressure plate; wherein,
and the horizontal spring is connected between the two horizontal spring end connecting blocks, and the horizontal spring is fixedly connected with the horizontal spring end connecting blocks through the horizontal spring end fixing pressing plate.
4. The cam roller negative stiffness structure low frequency vibration isolator of claim 3, wherein the negative stiffness spring-connected cylindrical roller is composed of a horizontal spring-connected cylindrical roller, a cylindrical roller hinge support block and a cylindrical roller hinge support block connecting rod; wherein,
the connecting rod of the cylindrical roller hinge support block is connected to one side, opposite to the connecting cam of the bearing table, of the horizontal spring end connecting block, the tail end of the connecting rod of the cylindrical roller hinge support block is sequentially connected with the cylindrical roller hinge support block and the horizontal spring connecting cylindrical roller, and the horizontal spring connecting cylindrical roller and the cylindrical roller hinge support block are connected and installed in a hinge mode.
5. The cam roller negative stiffness structural low frequency vibration isolator of claim 4, wherein the negative stiffness spring positioning device is composed of a horizontal spring positioning connecting plate and a horizontal spring linear slide rail; wherein,
and a horizontal spring positioning connecting plate is fixedly connected below the horizontal spring end connecting block, and a horizontal spring linear sliding rail is connected below the horizontal spring positioning connecting plate.
6. The cam roller negative stiffness structural low frequency vibration isolator of claim 5, wherein the horizontal direction negative stiffness spring compression adjusting device is composed of a horizontal spring compression adjusting knob and a horizontal spring adjusting knob fixed block; wherein,
the horizontal spring compression amount adjusting knob is connected with the horizontal spring adjusting knob fixing block, and the horizontal spring end connecting block adjusts the installation compression amount of the horizontal spring through the horizontal spring compression amount adjusting knob.
7. The cam roller negative stiffness structural low frequency vibration isolator of claim 6, wherein the negative stiffness spring floor fixture is a horizontal spring floor connection block; the horizontal spring adjusting knob fixing block and the horizontal spring linear slide rail are fixedly connected to the horizontal spring bottom plate connecting block through bolts.
8. The cam roller negative stiffness structural low frequency vibration isolator of claim 7 wherein the baseplate fixed support means is comprised of a model baseplate and a model footpad; wherein, a model pad is fixed under the model bottom plate; two horizontal spring bottom plate connecting blocks and a vertical spring linear bearing are fixed above the model bottom plate in a bolt mode, and the two horizontal spring bottom plate connecting blocks are located on two sides of the vertical spring linear bearing.
9. The cam roller negative stiffness structural low frequency vibration isolator of any one of claims 3 to 8, wherein a horizontally placed damper is further connected between the two horizontal spring end connecting blocks on the two sides respectively.
10. The cam roller negative stiffness structure low frequency vibration isolator of claim 1, wherein the connection and installation of the components of the cam roller negative stiffness structure low frequency vibration isolator are distributed symmetrically with respect to a plane which is perpendicular to the bottom plate fixed support device and in which a central axis of the vertical positive stiffness spring is located.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107740843A (en) * | 2017-11-17 | 2018-02-27 | 北京市劳动保护科学研究所 | A kind of cam bawl negative stiffness structure low frequency vibration isolation device |
| CN109751361A (en) * | 2019-01-25 | 2019-05-14 | 哈尔滨工业大学 | A kind of negative stiffness element and negative stiffness characteristic generation method and application with equilbrium position self-regulation ability |
| CN112377549A (en) * | 2020-11-03 | 2021-02-19 | 同济大学 | Multi-direction quasi-zero rigidity vibration isolation platform |
-
2017
- 2017-11-17 CN CN201721543531.0U patent/CN207485957U/en active Active
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107740843A (en) * | 2017-11-17 | 2018-02-27 | 北京市劳动保护科学研究所 | A kind of cam bawl negative stiffness structure low frequency vibration isolation device |
| CN109751361A (en) * | 2019-01-25 | 2019-05-14 | 哈尔滨工业大学 | A kind of negative stiffness element and negative stiffness characteristic generation method and application with equilbrium position self-regulation ability |
| CN112377549A (en) * | 2020-11-03 | 2021-02-19 | 同济大学 | Multi-direction quasi-zero rigidity vibration isolation platform |
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