Nonlinear simple shock absorber

Abstract

The invention provides a nonlinear simple shock absorber, which belongs to the technical field of vibration control and energy dissipation, and comprises a shell, a mass block, a plurality of layers of bulge structures and a viscoelastic material block, the shell is used for being fixed to a vibration source component, the interior of the shell is slidably connected with the mass block in the vibration direction of the vibration source component, and buffer spaces are formed between the mass block and the inner walls of the two opposite sides of the shell. The multiple layers of protruding structures are arranged on one of the mass block and the shell, and the protruding areas are reduced layer by layer; the viscoelastic material block is arranged on the other one of the mass block and the shell and corresponds to the multiple layers of protruding structures in position. According to the non-linear simple shock absorber, non-linear change of the contact area is achieved through graded contact between the multiple layers of protruding structures and the viscoelastic material blocks so that a non-linear curve and damping response can be obtained, and therefore broadband vibration suppression can be achieved, the complex multi-parameter coupling debugging process is avoided, and the damping effect is improved. And the structure is simple, the environmental adaptability is high, and the long-term stability is good.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of vibration control and energy dissipation, and particularly relates to a simple nonlinear damper. BACKGROUND

[0002] Vibration control and energy dissipation technology is a key link in the design of modern mechanical systems, civil structures and precision equipment, and its core goal is to reduce the vibration response amplitude caused by external excitation through energy dissipation or structural optimization. In traditional design, the common vibration control device is mainly a linear damping system, such as a linear spring-damping system. When the external excitation frequency is close to the natural frequency of the system, the linear damping system will have a significant resonance amplification effect, resulting in a sharp decline in damping performance. Moreover, since the equivalent stiffness and damping coefficient of the linear system are fixed constants, they cannot be automatically adjusted according to the changes in excitation amplitude and frequency, so it is difficult to achieve wideband or adaptive damping effect. Therefore, nonlinear damping technology has gradually become a research hotspot.

[0003] Nonlinear damping technology introduces geometric nonlinearity or material nonlinearity to make the system exhibit variable stiffness characteristics under different amplitude or frequency conditions, thereby achieving better energy dissipation and vibration isolation performance. Existing nonlinear damping schemes include: using a multi-stage spring combination structure to obtain a nonlinear restoring force; using a trajectory constraint mechanism (such as an arc track or cam structure) to generate a nonlinear geometric coupling; and using a magnetorheological fluid or an electrorheological material to achieve controllable damping.

[0004] At present, the above existing nonlinear damping schemes still have the following problems: the multi-stage spring combination structure and the trajectory constraint mechanism have a complex structure and require high assembly precision, so the application cost is too high; the magnetorheological fluid and the electrorheological material are greatly affected by temperature, humidity and aging, and their performance decays significantly, so they have poor long-term stability; and the nonlinear dynamic response under multi-parameter coupling is difficult to accurately predict, so the design and control are extremely difficult. SUMMARY

[0005] The embodiments of the present application provide a simple nonlinear damper, which aims to solve the problems of the existing nonlinear damping schemes mentioned in the background technology, simplify the structure of the nonlinear damping scheme, reduce the control difficulty, and improve the damping frequency bandwidth and long-term use stability.

[0006] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is to provide a simple nonlinear damper, which comprises: a shell for being fixed to a vibration source component; a mass block slidingly connected to the shell along the vibration direction of the vibration source component, and forming a buffer space between the inner walls of the shell on both sides in the sliding direction of the mass block; Two pairs of viscoelastic energy dissipation components are arranged in the two buffer spaces respectively, and each viscoelastic energy dissipation component comprises a pressing part formed on the inner wall of the shell and a viscoelastic part formed on the mass block, and the pressing part and the viscoelastic part are in corresponding contact. The contact area between the pressing part and the viscoelastic part changes nonlinearly with the vibration energy transmitted to the shell by the vibration source member.

[0007] In a possible implementation, the shell comprises: a bottom shell for fixedly connecting the vibration source member, and the inner bottom wall of the bottom shell and the mass block have a buffer space therebetween; a top cover covering the bottom shell and having a buffer space between the mass block and the top cover; The opposite surfaces of the bottom shell and the top cover are both provided with a plurality of protruding structures as the pressing parts.

[0008] In some embodiments, the protruding area of the plurality of protruding structures decreases layer by layer, and the mass block is provided with viscoelastic material blocks as the viscoelastic parts at the center positions of the two sides thereof; and at least one protruding structure of the plurality of protruding structures is in contact with a corresponding viscoelastic material block based on the vibration energy.

[0009] For example, the center of the viscoelastic material block is provided with a stepped hole, and the stepped hole is adapted to be embedded with the plurality of protruding structures layer by layer and to be in contact with the corresponding stepped surface.

[0010] For example, the inner bottom wall of the bottom shell is symmetrically provided with two guide rods as the center of the plurality of protruding structures; and the two guide rods are both slid through the mass block and connected to the top cover.

[0011] In a possible implementation, the two guide rods are respectively sleeved with wear-resistant sleeves along the respective axial directions, and the two wear-resistant sleeves are embedded in the mass block.

[0012] In some embodiments, the inner bottom wall of the bottom shell is provided with first insertion holes adapted to insert the guide rods, and the surface of the top cover facing the inside of the bottom shell is provided with second insertion holes adapted to insert the guide rods.

[0013] For example, the first insertion hole and the second insertion hole are both provided with first adjusting pads, and the second adjusting pad is arranged between the top cover and the bottom shell.

[0014] For example, the two opposite outer walls of the bottom shell are provided with connecting ears for connecting the vibration source member.

[0015] In some embodiments, the top cover is provided with a support adapted to conform to the mounting surface of the vibration source member.

[0016] The non-linear simple damper has the advantages that, compared with the prior art, the shell is fixed on the vibration source component, so that the vibration can be directly transmitted to the shell, the mass block connected to the shell in the vibration direction is caused to reciprocate, the vibration energy is converted into the kinetic energy of the mass block, the viscoelastic part of the mass block repeatedly bears the pressure of the pressure part formed on the inner wall of the shell when the mass block reciprocates, the viscoelastic part is caused to be coupled and deformed by shearing and compression, the kinetic energy of the mass block is converted into the heat energy of the viscoelastic part and dissipated, and thus the vibration damping effect on the vibration source component is achieved.

[0017] The pressure contact area of the pressure part on the viscoelastic part can change nonlinearly with the change of the vibration energy, and the nonlinear change of the pressure contact area can cause the stiffness of the viscoelastic part to appear a nonlinear damping response, so that the wideband vibration of the vibration source component can be inhibited, the structure is simple, good long-term stability is achieved, and the controllable nonlinear mechanical response characteristics can be obtained without relying on a complex structure, so that the problems of difficult prediction of nonlinear dynamics response and complex debugging process under multi-parameter coupling are avoided. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The figure is a perspective structural schematic view of the non-linear simple damper provided by the embodiment of the present application. Figure 2 The figure is a sectional structural schematic view of the non-linear simple damper provided by the embodiment of the present application. Figure 3 The figure is an exploded structural schematic view of the non-linear simple damper provided by the embodiment of the present application. Figure 4 The figure is a schematic view of the mounting structure of the non-linear simple damper provided by the embodiment of the present application on the pipeline body.

[0019] In the figure: 10, shell; 11, bottom shell; 111, connecting lug; 12, top cover; 121, support; 13, first adjusting pad; 14, second adjusting pad; 20, guide rod; 21, wear-resistant sleeve; 30, mass block; 300, buffer space; 31, notch; 40, pressure part; 50, viscoelastic part; 501, stepped hole; 502, stepped surface; 60, pipeline body; 70, screw rod; 71, nut; 80, arc-shaped clamping plate. DETAILED DESCRIPTION

[0020] In order to make the technical problems, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0021] It should be noted that when an element is referred to as being "set on" or "connected to" another element, it can be directly on or indirectly on the other element. It should be understood that the terms "upper," "lower," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" or "several" means two or more, unless otherwise explicitly specified.

[0022] Please refer to the following: Figures 1 to 4 The nonlinear simple vibration damper provided by the present invention will now be described. The nonlinear simple vibration damper includes a housing 10, a mass block 30, and two pairs of viscoelastic energy dissipation components; the housing 10 is used to fix the vibration source component; the mass block 30 is slidably connected to the housing 10 along the vibration direction of the vibration source component, and a buffer space 300 is formed between the mass block 30 and the inner walls of the opposite sides of the housing 10 in the sliding direction; the two pairs of viscoelastic energy dissipation components are respectively disposed in the two buffer spaces 300, and the viscoelastic energy dissipation components include a pressing part 40 formed on the inner wall of the housing 10 and a viscoelastic part 50 formed on the mass block 30, with the pressing part 40 and the viscoelastic part 50 in corresponding contact; wherein, the pressing contact area between the pressing part 40 and the viscoelastic part 50 changes nonlinearly with the change of vibration energy transmitted from the vibration source component to the housing 10.

[0023] Compared with the prior art, the nonlinear simple vibration damper provided in this embodiment allows the vibration to be directly transmitted to the housing 10 by fixing the housing 10 to the vibration source component. This causes the mass block 30, which is slidably connected inside the housing 10 along the vibration direction, to reciprocate. At this time, the vibration energy is converted into the kinetic energy of the mass block 30. When the mass block 30 reciprocates, its viscoelastic part 50 is repeatedly subjected to the pressure of the pressure part 40 formed on the inner wall of the housing 10, causing the viscoelastic part 50 to undergo coupled deformation of shear and compression. This causes the kinetic energy of the mass block 30 to be converted into the heat energy of the viscoelastic part 50 and dissipated, thereby achieving the vibration reduction effect on the vibration source component.

[0024] Since the contact area between the pressure-absorbing part 40 and the viscoelastic part 50 can change nonlinearly with the change of vibration energy, and the nonlinear change of the contact area can cause the stiffness of the viscoelastic part 50 to have a nonlinear damping response, it is possible to achieve broadband vibration suppression of the vibration source component. It not only has a simple structure and good long-term stability, but also can obtain controllable nonlinear mechanical response characteristics without relying on complex structures, thereby avoiding the problems of difficult prediction of nonlinear dynamic response and complex debugging process under multi-parameter coupling.

[0025] In some embodiments, see Figure 2 The housing 10 includes a bottom shell 11 and a top cover 12; the bottom shell 11 is used to fix and connect the vibration source component, and there is a buffer space 300 between the inner bottom wall of the bottom shell 11 and the mass block 30; the top cover 12 covers the bottom shell 11 and has a buffer space 300 between it and the mass block 30; wherein, the center of the opposite surfaces of the bottom shell 11 and the top cover 12 are provided with a multi-layer protrusion structure as a pressing part 40.

[0026] The housing 10 adopts a detachable structure of bottom shell 11 and top cover 12, which not only facilitates processing and manufacturing but also facilitates the assembly of mass block 30 and viscoelastic material block. The bottom shell 11 and top cover 12 can be connected by several screws passing through the top cover 12 and screwing it to the side wall of the bottom shell 11, or by a snap-fit ​​connection based on corresponding buckles and holes on both, without specific limitations.

[0027] The housing 10 has multi-layered protrusions on both inner walls opposite each other along the axial direction of the guide rod 20, and the mass block 30 has viscoelastic portions 50 on both sides facing the two buffer spaces 300. Considering the bidirectional nature of vibration, the vibration energy transmitted from the vibration source component to the housing 10 causes the mass block 30 to reciprocate. Although a viscoelastic energy dissipation system with multi-layered protrusions and viscoelastic portions 50 on only one side can also dissipate vibration energy, the combined effect of having multi-layered protrusions and viscoelastic portions 50 on both sides along the vibration direction is better.

[0028] It should be noted that in this embodiment, the mass block 30 forms a viscoelastic energy dissipation system based on the squeezing action of the multi-layer protrusion structure on the viscoelastic part 50. The basic principle of energy dissipation is that the multi-layer protrusion structure squeezes the viscoelastic part 50, causing it to deform. The deformation of the viscoelastic part 50 causes the friction between its internal molecules to generate heat energy, which dissipates the energy. Thus, the vibration energy is converted into heat energy for energy dissipation.

[0029] For example, in this embodiment, the mass block 30 can be made of a high-density metal material, which serves to adjust the inertial parameters of the viscoelastic energy dissipation system to ensure that the main vibration mode frequency of the system is lower than the natural frequency of the structure. The viscoelastic part 50 is a representative material that can provide nonlinear restoring force, such as rubber materials (natural rubber, butyl rubber, isoprene rubber, ethylene propylene rubber), and polymer materials (dampening plastics with polyurethane, polystyrene, polyvinyl chloride, and epoxy resin as the matrix).

[0030] Specifically, such as Figure 2 As shown, the protrusion area of ​​the multi-layer protrusion structure decreases layer by layer; viscoelastic material blocks serving as viscoelastic parts 50 are provided at the center positions on both sides of the mass block 30; wherein, at least one layer of the multi-layer protrusion structure presses against the corresponding viscoelastic material block based on vibration energy.

[0031] Specifically, the aforementioned mass block 30 has a notch 31 at the center of each sidewall facing the two buffer spaces 300, and the viscoelastic material block is embedded in the notch 31. The function of the notch 31 is twofold: firstly, to improve the installation reliability of the viscoelastic material block and prevent it from falling off the mass block 30 after frequent stress; secondly, to provide radial constraint on the viscoelastic material block using the notch 31, thereby concentrating the deformation of the viscoelastic material block caused by the compression of the multi-layered protrusion structure in the vibration direction, which is beneficial to improving the efficiency of vibration energy dissipation.

[0032] The protrusion area of ​​the multi-layer protrusion structure decreases layer by layer. When the amplitude of the vibration source component is small, the motion amplitude of the mass block 30 is also relatively small. Only the topmost protrusion of the multi-layer protrusion structure compresses the viscoelastic material block, so the viscoelastic material block exhibits low stiffness characteristics. As the amplitude of the vibration source component increases, the motion amplitude of the mass block 30 also increases, and the number of layers of the multi-layer protrusion structure compressing the viscoelastic material block gradually increases. At this time, the stiffness of the viscoelastic material block exhibits a nonlinear increase. Thus, the nonlinear change of the contact area is achieved by utilizing the graded contact between the multi-layer protrusion structure and the viscoelastic material block to obtain the nonlinear curve and damping response.

[0033] In this embodiment, the multi-layered protrusion structure can be a multi-layered structure with different shapes and thicknesses, such as... Figure 2 As shown, taking a three-layer protrusion structure as an example, the first layer protrusion has the largest area and the smallest surface curvature, or it can directly adopt a gentle slope structure. The second layer protrudes from the surface of the first layer and has a smaller area. The surface curvature of the second layer protrusion is larger than that of the first layer. The third layer protrudes from the surface of the second layer and its area is further reduced and its curvature is further increased, forming a protrusion that is close to a hemispherical shape.

[0034] Based on the aforementioned three-layer protrusion structure, when the periodic or transient excitation of the vibration source component is transmitted to the shell 10, the mass block 30 undergoes vibrational displacement relative to the shell 10, while the viscoelastic material block deforms under the dual stresses of compression and shear from the three-layer protrusion structure. Specifically, in the low-amplitude vibration stage, only the third layer of protrusions compresses the viscoelastic material block, resulting in a low equivalent stiffness and a flexible response. As the amplitude increases, the second and first layers of protrusions gradually participate in compressing the viscoelastic material block, and the system stiffness exhibits a non-linear increase during this process. Through the geometric design of the multi-layer protrusion structure (including but not limited to curvature variations and protrusion height differences), different contact stiffness ranges can be introduced at different vibration energy levels, forming a staged stiffness modulation mechanism without the need for complex spring-damping systems and magnetorheological coupling control.

[0035] It should be noted that, as Figure 2 As shown, in this embodiment, the viscoelastic material block has a stepped hole 501 at its center. The stepped hole 501 is suitable for the multi-layered protrusion structure to be embedded layer by layer to press against the corresponding stepped surface 502. The purpose of setting the stepped hole 501 is to allow the multi-layered protrusion structure to be embedded layer by layer into each hole segment to compress the corresponding stepped surface 502, thereby avoiding mutual interference between the compression effects of adjacent protrusions on the viscoelastic material block, thus enabling the viscoelastic material block to obtain the expected nonlinear stiffness change curve. In addition, the timing of each layer of protrusions pressing against the corresponding stepped surface 502 can be adjusted by changing the height difference between adjacent stepped surfaces 502, thereby adjusting the equivalent resonant frequency and energy dissipation rate of the system. Thus, by replacing different viscoelastic material blocks, the parameter adjustability of the viscoelastic energy dissipation system can be achieved, thereby adapting to different excitation frequencies and vibration conditions.

[0036] For one specific connection method of the aforementioned mass block 30 within the housing 10, please refer to [link / reference]. Figures 1 to 4 The inner bottom wall of the bottom shell 11 is symmetrically equipped with two guide rods 20 around a multi-layered protruding structure. Both guide rods 20 slide through the mass block 30 and connect to the top cover 12. By using the two guide rods 20 symmetrically arranged on both sides of the multi-layered protruding structure to slide and interlock with the mass block 30, the stability of the mass block 30 under vibration can be improved, and assembly and processing can be facilitated.

[0037] To ensure smooth sliding of the mass block 30 on the guide rod 20, and to avoid wear caused by frequent sliding friction between the two, such as... Figure 2 As shown, in this embodiment, each of the two guide rods 20 is slidably fitted with a wear-resistant sleeve 21 along its respective axial direction, and both wear-resistant sleeves 21 are embedded in the mass block 30. The wear-resistant sleeve 21 can be a copper sleeve or a polytetrafluoroethylene sleeve. Furthermore, lubricating grease can be applied between the wear-resistant sleeve 21 and the guide rod 20 to reduce frictional resistance and help improve service life.

[0038] For some possible implementations, please refer to [link / reference].Figure 2 The bottom wall of the bottom shell 11 is provided with a first insertion hole suitable for inserting the guide rod 20, and the surface of the top cover 12 facing the inside of the bottom shell 11 is provided with a second insertion hole suitable for inserting the guide rod 20. Both the first insertion hole and the second insertion hole are blind holes. Using the first insertion hole and the second insertion hole as the connection base for the guide rod 20, the structure is simple and easy to assemble.

[0039] Optionally, please see Figure 2 In this embodiment, a first adjusting pad 13 is provided in both the first and second sockets, and a second adjusting pad 14 is sandwiched between the top cover 12 and the bottom shell 11.

[0040] By changing the thickness of the first adjusting component or increasing or decreasing the thickness of the first adjusting pad 13, and simultaneously changing the thickness or increasing or decreasing the number of the second adjusting pad 14, the internal dimensions of the housing 10 in the axial direction of the guide rod 20 can be adjusted, thereby adjusting the size of the buffer space 300. This, in turn, changes the initial gap or pre-tightening state between the viscoelastic material block and the multi-layer protrusion structure, thereby achieving the adjustment of the resonant frequency and energy dissipation rate, thus adapting to different excitation frequencies and vibration conditions.

[0041] It should be noted that, in combination Figure 1 and Figure 4 It is understood that the bottom shell 11 has connecting lugs 111 on its two opposite outer walls for connecting the vibration source component. By providing connecting lugs 111, the ease and reliability of installing the bottom shell 11 on the vibration source component can be improved.

[0042] For example, see Figure 1 and Figure 4 The top cover 12 is provided with a support 121 adapted to conform to the mounting surface of the vibration source component. The support 121 can form a fitting surface adapted to the mounting surface of the vibration source component. This improves the installation stability of the housing 10 on the vibration source component through the tight contact between the support 121 and the mounting surface, thereby ensuring that the vibration energy can be completely transferred to the housing 10. This is beneficial to improving the efficiency of the viscoelastic energy dissipation system composed of viscoelastic material blocks and multi-layer protrusion structures inside the housing 10.

[0043] It should be noted that the nonlinear simple vibration damper provided in this application is applicable to vibration suppression scenarios in mechanical systems, civil structures, and precision equipment. Therefore, the vibration source component can be understood as the component prone to vibration in the above scenarios. Taking pipe vibration suppression in civil structures as an example, the vibration source component is the pipe body 60, and the connection method between the shell 10 and the pipe body 60 is as follows: Figure 4 As shown: The support 121 has an arc surface that fits against the peripheral wall of the pipe body 60. The two connecting ears 111 are respectively hinged to the screws 70 by pins. The housing 10 is provided with an arc-shaped clamp 80 that fits against the pipe body 60. After the two screws 70 are passed through the arc-shaped clamp 80, the nuts 71 are screwed on, so that the arc-shaped clamp 80 fits with the pipe body 60 to clamp it. The installation is simple and stable and reliable.

[0044] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. Nonlinear simple shock absorber, characterized by, include: Housing, used to fix it to the vibration source component; The mass block is slidably connected to the housing along the vibration direction of the vibration source component, and forms a buffer space between itself and the inner walls of the opposite sides of the housing in the sliding direction; Two pairs of viscoelastic energy dissipation components are respectively disposed in the two buffer spaces. Each viscoelastic energy dissipation component includes a pressing part formed on the inner wall of the shell and a viscoelastic part formed on the mass block. The pressing part and the viscoelastic part are in corresponding contact. The contact area between the pressing part and the viscoelastic part varies nonlinearly with the change in vibration energy transmitted from the vibration source component to the shell.

2. The non-linear simple shock absorber according to claim 1, wherein The housing includes: A bottom shell is used to fix the vibration source component, and the buffer space is provided between the inner bottom wall of the bottom shell and the mass block; A top cover, which encloses the bottom shell and has the buffer space between it and the mass block; The bottom shell and the top cover each have a multi-layered protruding structure at the center of their opposite surfaces, which serves as the pressure-retaining part.

3. The non-linear simple shock absorber according to claim 2, wherein The protrusion area of ​​the multi-layer protrusion structure decreases layer by layer; viscoelastic material blocks serving as viscoelastic parts are provided at the center positions on both sides of the mass block; wherein, at least one layer of the multi-layer protrusion structure presses against the corresponding viscoelastic material block based on the vibration energy.

4. The non-linear simple shock absorber according to claim 3, wherein The viscoelastic material block has a stepped hole at its center, which is suitable for the multi-layered protrusion structure to be embedded layer by layer to press against the corresponding stepped surface.

5. The non-linear simple shock absorber according to claim 2, wherein The inner bottom wall of the bottom shell is symmetrically provided with two guide rods around the multi-layer protrusion structure; both guide rods slide through the mass block and are connected to the top cover.

6. The non-linear simple shock absorber according to claim 5, wherein Each of the two guide rods is slidably fitted with a wear-resistant sleeve along its respective axis, and both wear-resistant sleeves are embedded in the mass block.

7. The non-linear simple shock absorber according to claim 5, wherein The inner bottom wall of the bottom shell is provided with a first insertion hole suitable for inserting the guide rod, and the surface of the top cover facing the inside of the bottom shell is provided with a second insertion hole suitable for inserting the guide rod.

8. The non-linear simple shock absorber according to claim 7, wherein Both the first and second sockets are provided with a first adjusting pad, and a second adjusting pad is sandwiched between the top cover and the bottom shell.

9. The non-linear simple shock absorber according to claim 5, wherein The bottom shell has connecting lugs on its two opposite outer walls for connecting the vibration source component.

10. The non-linear simple shock absorber according to claim 5, wherein The top cover is provided with a support suitable for conforming to the mounting surface of the vibration source component.

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