Semi-active pipe isolator

Abstract

The application discloses a semi-active pipeline isolator, which comprises a nonlinear modulation unit and a passive isolation unit arranged in an upper layer and a lower layer, the nonlinear modulation unit is connected with a coil in an actuator through a switch modulation circuit to form a loop, the pipeline vibration can be nonlinearly modulated and inhibited from being transmitted to a mounting base, and good pipeline isolation effect is achieved; the semi-active pipeline isolator not only breaks through the problem that the isolation effect of an existing isolator on low-frequency vibration is limited, but also has the characteristics of a traditional semi-active isolator, such as low price and low energy consumption, the lower passive isolation unit has the advantages of a traditional passive isolator, such as simple structure, small size and low cost, and thus forms an isolation system which has the advantages of simple structure, small space volume, low energy consumption, low cost, good isolation effect and applicability to various vibration conditions, and can meet the characteristics of complex pipeline system structure, space limitation and high vibration control requirement of existing buildings and ships.

Description

Technical Field

[0001] This invention relates to the field of pipeline vibration isolation technology, and in particular to a semi-active pipeline vibration isolator. Background Technology

[0002] With increasingly stringent requirements for vibration and noise control in pipelines within structures such as buildings and ships, the demand for pipeline vibration isolation technology and related products, as a key control technology, is becoming increasingly urgent. In general pipeline systems, pipelines require support structures such as pedestals, pipe supports, and hangers to provide support. For pipelines with certain vibration isolation requirements, adding springs can achieve a certain vibration isolation effect. However, in special applications such as ships with stringent requirements for pipeline vibration control, pipeline vibration isolators need to be installed to reduce the transmission of pipeline system vibration to the mounting foundation through the support structure.

[0003] Existing pipeline vibration isolators can be broadly classified into three types:

[0004] The first type is a passive vibration isolator composed of an elastic element and a mass block. This type of vibration isolator has a simple structure, few components, and low cost. However, the inherent characteristics of the vibration isolator system cannot be adjusted after installation. It has a good vibration isolation effect for high-frequency vibrations that are much higher than the vibration isolator's natural frequency, but it has a poor vibration isolation effect for low-frequency vibrations that are close to or lower than the vibration isolator's natural frequency, or even cannot play a vibration isolation role.

[0005] The second type is the fully active vibration isolator. Its principle is based on passive vibration isolation, using actuators connected in parallel or replacing components in the system. Taking the vibration information from the primary vibration source as input, and according to a certain control strategy, the actuator acts as a secondary vibration source to apply active control force to the controlled object, causing the vibration response generated at the desired location to cancel out the original excitation's vibration response. This type of isolator can adjust the actuator's output according to the system's vibration input characteristics, thus providing better vibration isolation and adaptability to varying operating conditions. However, fully active vibration isolators have a large number of components, complex structures, and high prices. Furthermore, active vibration isolators, also known as powered vibration isolators, require external power supply, resulting in higher energy consumption.

[0006] The third type is a semi-active vibration isolator, which, based on passive vibration isolation, alters the natural frequency and characteristics of a system by adjusting the stiffness and inertia of certain components in real time. Semi-active vibration isolators adjust the stiffness, inertia, and damping characteristics of certain components in the system in real time according to changes in system input and requirements for system output, thereby enabling the system to achieve excellent dynamic characteristics. However, the working principle of existing semi-active vibration isolators is based on linear vibration isolation, meaning the natural frequency cannot be infinitely small. While they have excellent vibration isolation effects for high-frequency vibrations much higher than the isolator's natural frequency, their isolation effect is poor for low-frequency vibrations close to or below the isolator's natural frequency, and they may even amplify the vibration response.

[0007] In summary, while fully active vibration isolators offer good vibration isolation and adaptability to varying operating conditions, they are structurally complex, expensive, and energy-intensive. Passive and semi-active vibration isolators, on the other hand, are simple in structure, low in cost, and low in energy consumption, but they are based on linear isolation principles, and their isolation effectiveness in the low-frequency region is limited by the natural frequency. Therefore, it is necessary to propose a novel pipeline vibration isolator to address the problems of the existing technologies. Summary of the Invention

[0008] The purpose of this invention is to provide a novel semi-active pipeline vibration isolator, which, by nonlinearly modulating the vibration propagation path from the pipeline to the installation foundation, can disperse vibration energy below the isolator's natural frequency into the isolator's operating frequency range, thereby achieving control of pipeline vibration. This solves the problem that existing pipeline vibration isolators, based on the linear vibration isolation principle, have their vibration isolation effect limited by the natural frequency in the low-frequency region.

[0009] To achieve the above objectives, the present invention provides the following solution:

[0010] This invention provides a semi-active pipeline vibration isolator, comprising:

[0011] The nonlinear modulation unit includes an actuator and a switching modulation circuit. The switching modulation circuit is connected to the coil in the actuator to form a loop. The actuator's mover is used to connect to the vibration-isolated pipeline. When the mover transmits low-frequency vibration from the pipeline, the switching modulation circuit can switch the on / off state of the loop several times within one vibration cycle of the low-frequency vibration to perform nonlinear modulation on the low-frequency vibration and decompose the low-frequency vibration into multiple high-frequency vibrations.

[0012] A passive vibration isolation unit is disposed below the actuator. The passive vibration isolation unit includes a base, an elastic element and a mass block arranged sequentially from bottom to top. The base is used to connect to the mounting foundation, and the mass block is connected to the actuator. The passive vibration isolation unit is used to suppress the high-frequency vibration of the isolated pipeline and the high-frequency vibration formed by the decomposition of the low-frequency vibration.

[0013] Optionally, the actuator is an electric actuator or an electromagnetic actuator.

[0014] Optionally, the actuator is an electromagnetic actuator, which includes:

[0015] The outer casing, the bottom of which is connected to the mass block;

[0016] An electromagnetic component is disposed within the housing. The electromagnetic component includes an inner magnet, an outer magnet, a permanent magnet, and a coil. The inner magnet is fitted inside the outer magnet. The permanent magnet is fitted between the inner magnet and the outer magnet. The coil is movably fitted between the inner magnet and the outer magnet, and the coil is located above the permanent magnet.

[0017] The mover is movably inserted into the inner ring of the inner magnet and connected to the coil. The mover can drive the coil to reciprocate in the magnetic circuit composed of the inner magnet, the outer magnet and the permanent magnet under the action of pipeline vibration, so that the coil cuts the magnetic field lines to generate current. The mover and the outer shell generate an interaction force under the dual action of current and magnetic field.

[0018] Optionally, at least one of the mover and the housing is made of stainless steel; or, at least one of the mover and the housing is made of carbon fiber.

[0019] Optionally, the mover has a through hole through which the wire of the coil passes.

[0020] Optionally, the switching modulation circuit includes an impedance circuit, a field-effect transistor (FET), and a switching signal generation circuit. The impedance circuit, the FET, and the coil are connected to form the loop. The switching signal generation circuit is connected to the FET and can control the FET to switch between an off state and an on state to switch the on / off state of the loop.

[0021] Optionally, the field-effect transistor is a metal-oxide-semiconductor field-effect transistor; the switching signal generation circuit is an oscillator with a 555 timer.

[0022] Optionally, it also includes a clamp for connecting the vibration-isolated pipeline, the clamp being connected to the top end of the mover.

[0023] Optionally, the pipe clamp includes a lower pipe clamp seat, an upper pipe clamp, and a fastening bolt. The upper pipe clamp and the lower pipe clamp seat are connected together, and the fastening bolt passes through the upper pipe clamp and the lower pipe clamp seat in sequence and is threadedly connected to the moving part.

[0024] Optionally, the inner ring of the pipe clamp is also provided with a soft pad.

[0025] Optionally, the padding is a rubber sheet.

[0026] Optionally, the elastic element is a rubber block.

[0027] Optionally, the mass block is provided with two sets of nonlinear modulation units, and the two movers of the two sets of nonlinear modulation units are symmetrically connected to both sides of the pipe clamp.

[0028] The present invention achieves the following technical effects compared to the prior art:

[0029] The semi-active pipeline vibration isolator proposed in this invention includes a nonlinear modulation unit and a passive vibration isolation unit arranged in upper and lower layers. The nonlinear modulation unit includes an actuator and a switching modulation circuit. The switching modulation circuit is connected to the coil in the actuator to form a loop. The actuator's mover is used to connect to the pipeline to be isolated. When the mover transmits low-frequency vibration from the pipeline, the switching modulation circuit can switch the on / off state of the loop several times within one vibration cycle of the low-frequency vibration to perform nonlinear modulation on the low-frequency vibration and decompose the energy of the low-frequency vibration into the energy of multiple high-frequency vibrations. The passive vibration isolation unit is located below the actuator. The passive vibration isolation unit includes a base, an elastic element, and a mass block arranged sequentially from bottom to top. The mass block is connected to the actuator. The passive vibration isolation unit is used to suppress the high-frequency vibration of the pipeline to be isolated and the high-frequency vibration formed by the decomposition of low-frequency vibration. The aforementioned semi-active pipeline vibration isolator does not require energy to be fed into the nonlinear modulation unit. Through the nonlinear control of the switching modulation circuit, a vibration below the natural frequency of the isolator can be modulated into multiple vibrations above the natural frequency of the isolator. By utilizing the vibration isolation characteristics of the passive vibration isolation unit, the transmission of pipeline vibration to the installation foundation is reduced, thereby achieving the purpose of efficient vibration isolation.

[0030] The aforementioned semi-active pipeline vibration isolator achieves excellent pipeline vibration isolation by nonlinearly modulating pipeline vibration and suppressing its transmission to the installation foundation. This semi-active pipeline vibration isolator not only overcomes the problem of limited vibration isolation effect of existing vibration isolators for low-frequency vibrations, but also features a nonlinear modulation unit in the upper layer that is low in price and energy consumption, while a passive vibration isolation unit in the lower layer has the advantages of simple components, small size, and low cost. This forms a vibration isolation system that is simple in structure, small in size, low in energy consumption, low in cost, and has good vibration isolation effect, and is suitable for various vibration conditions. It can meet the characteristics of complex structure, space constraints, and high vibration control requirements of existing pipeline systems in buildings, ships, etc. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the overall structure of the semi-active pipeline vibration isolator disclosed in an embodiment of the present invention;

[0033] Figure 2This is a schematic diagram of the electromagnetic actuator in the semi-active pipeline vibration isolator disclosed in an embodiment of the present invention;

[0034] Figure 3 This is a schematic diagram of the switching modulation circuit in the semi-active pipeline vibration isolator disclosed in an embodiment of the present invention;

[0035] Figure 4 This is a schematic diagram illustrating the working principle of the switching modulation circuit in the semi-active pipeline vibration isolator disclosed in the embodiments of the present invention.

[0036] The attached figures are labeled as follows:

[0037] 100. Semi-active pipeline vibration isolator;

[0038] 1. Passive vibration isolation unit; 11. Base; 12. Elastic element; 13. Mass block; 14. Connecting bolts;

[0039] 2. Nonlinear modulation unit; 21. Actuator; 211. Mover; 212. Inner magnet; 213. Upper elastic ring; 214. Coil; 215. Outer magnet; 216. Permanent magnet; 217. Housing; 218. Bolt; 219. Bottom elastic body; 2110. Threaded hole; 22. Switching modulation circuit; 221. Impedance circuit; 222. Field-effect transistor; 223. Switching signal generation circuit;

[0040] 3. Pipe clamp; 31. Lower pipe clamp seat; 32. Upper pipe clamp; 33. Fastening bolt; 34. Soft washer;

[0041] 4. Vibration-isolated pipelines. Detailed Implementation

[0042] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] One of the objectives of this invention is to provide a novel semi-active pipeline vibration isolator that, by nonlinearly modulating the vibration propagation path from the pipeline to the installation foundation, can disperse vibration energy below the isolator's natural frequency into the isolator's operating frequency range, thereby achieving control over pipeline vibration. This solves the problem that existing pipeline vibration isolators, based on the linear vibration isolation principle, are limited by their natural frequency in the low-frequency region.

[0044] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0045] Example 1

[0046] like Figures 1-4 As shown, this embodiment provides a semi-active pipeline vibration isolator 100, which includes a nonlinear modulation unit 2 and a passive vibration isolation unit 1 arranged in upper and lower layers. The nonlinear modulation unit 2 includes an actuator 21 and a switching modulation circuit 22. The switching modulation circuit 22 is connected to the coil 214 in the actuator 21 to form a loop. The mover 211 of the actuator 21 is used to connect to the pipeline 4 to be isolated. When the mover 211 transmits low-frequency vibration from the pipeline, the switching modulation circuit 22 can switch the on and off state of the loop several times within one vibration cycle of the low-frequency vibration to perform nonlinear modulation on the low-frequency vibration and decompose the energy of the low-frequency vibration into the energy of multiple high-frequency vibrations. The passive vibration isolation unit 1 is disposed below the actuator 21. The passive vibration isolation unit 1 includes a base 11, an elastic element 12 and a mass block 13 arranged sequentially from bottom to top. The base 11 is used to connect to the mounting foundation, and the mass block 13 is connected to the actuator 21. The passive vibration isolation unit 1 is used to suppress the high-frequency vibration of the pipeline 4 to be isolated and the high-frequency vibration formed by the decomposition of the low-frequency vibration. The aforementioned "low-frequency vibration energy" refers to vibration energy below or close to the natural frequency of the passive vibration isolation unit 1, while "high-frequency vibration energy" refers to vibration energy above the natural frequency of the passive vibration isolation unit 1. The energy of high-frequency vibration is within the operating frequency range of the passive vibration isolation unit 1. The essence of the aforementioned semi-active pipeline vibration isolator 100 is to achieve nonlinear modulation by controlling the on / off state of the actuator coil and its shunt circuit. That is, through the nonlinear control of the switching modulation circuit 22, a vibration below the natural frequency of the isolator can be modulated into multiple vibrations above the natural frequency of the isolator. By utilizing the vibration isolation characteristics of the passive vibration isolation unit 1 (passive vibration isolator), the transmission of pipeline vibration to the installation foundation is reduced, thereby achieving the purpose of efficient vibration isolation.

[0047] In this embodiment, the actuator 21 is generally selected as an electric actuator or an electromagnetic actuator. This embodiment preferably uses an electromagnetic actuator, such as... Figure 2As shown, it includes a housing 217, an electromagnetic assembly, and the aforementioned mover 211. The housing 217 is located on top of the mass block 13, and its bottom is connected to the mass block 13. The electromagnetic assembly is disposed inside the housing 217 and includes an inner magnet 212, an outer magnet 215, a permanent magnet 216, and the aforementioned coil 214 (also called a "voice coil"). The inner magnet 212 is fitted inside the outer magnet 215, the permanent magnet 216 is fitted between the inner magnet 212 and the outer magnet 215, and the coil 214 is movably fitted inside the outer magnet 215. Between the inner magnet 212 and the outer magnet 215, and above the permanent magnet 216, the moving element 211 is movably inserted into the inner ring of the inner magnet 212 and fixedly connected to the coil 214. Under the action of pipeline vibration, the moving element 211 can drive the coil 214 to reciprocate up and down in the magnetic circuit composed of the inner magnet 212, the outer magnet 215 and the permanent magnet 216, so that the coil 214 cuts the magnetic field lines to generate current. The moving element 211 and the outer shell 217 generate an interaction force under the dual action of current and magnetic field. Since the moving element 211 and the outer shell 217 are respectively connected to the vibration-isolated pipeline 4 and the mass block 13, when the moving element 211 and the outer shell 217 generate an interaction force, the vibration energy of the vibration-isolated pipeline 4 can be transferred to the passive vibration isolation unit 1 in sequence through the moving element 211 and the outer shell 217. Compared to existing vibration isolators, pipeline vibrations below or close to the system's natural frequency can be isolated through nonlinear dispersion. At the same time, compared to fully active vibration isolators and traditional semi-active vibration isolators, the vibration isolation effect is no longer limited by the operating conditions, and the system structure is simple, with a smaller installation volume and weight, lower price, and lower energy consumption.

[0048] In this embodiment, at least one of the mover 211 and the outer shell 217 is made of stainless steel; or, at least one of the mover 211 and the outer shell 217 is made of carbon fiber.

[0049] In this embodiment, the actuator 211 has a through hole for the wire of the coil 214 to pass through, so that the wire of the coil 214 can pass out of the through hole to the outside of the actuator and connect with the switch modulation circuit 22 to form a loop.

[0050] In this embodiment, the actuator 211 includes a top rod, a bottom rod, and a cover plate connecting the top rod and the bottom rod. The cover plate is adapted to fit the top opening of the housing 217. When the actuator 21 is not in operation, the cover plate can precisely cover the top opening of the housing 217 to prevent external dust and other impurities from entering the interior of the housing 217. The top rod and the bottom rod are arranged coaxially. The bottom rod is movably inserted into the inner ring of the inner magnet 212. The coil 214 is wrapped around the outer circumference of the bottom rod and connected to the bottom surface of the cover plate. The top rod is located at the top of the cover plate, and a threaded hole 2110 is opened at the top end of the top rod. The threaded hole 2110 is generally arranged coaxially with the top rod. The aforementioned through hole for the wire of the coil 214 to pass through is opened on the cover plate of the actuator 211.

[0051] Furthermore, considering that the mover 211 moves up and down relative to the outer casing 217 and its internal electromagnetic components during operation, in order to avoid collision damage between the mover 211 and the outer casing 217 and its internal electromagnetic components, this embodiment also provides a bottom elastic body 219 between the bottom end of the bottom rod of the mover 211 and the outer casing 217 to buffer the impact of the bottom rod of the mover 211 on the outer casing 217, such as... Figure 2 As shown, the bottom elastic body 219 can be a rubber block or a spring, which is fixed to the bottom end of the base rod of the housing 217 or the mover 211.

[0052] Similarly, such as Figure 2 As shown, in this embodiment, an upper elastic ring 213 is also provided between the cover plate of the mover 211 and the outer magnet 215. The upper elastic ring 213 can be a rubber ring or a spring, which is fixed to the outer magnet 215 or the cover plate of the mover 211.

[0053] In this embodiment, as Figure 3 As shown, the switching modulation circuit 22 includes an impedance circuit 221, a field-effect transistor 222, and a switching signal generation circuit 223. The impedance circuit 221, the field-effect transistor 222, and the coil 214 are connected to form a loop. The switching signal generation circuit 223 is electrically connected to the field-effect transistor 222. The switching signal generation circuit 223 can control the field-effect transistor 222 to switch between the open and closed states, so as to switch the on and off states of the loop and achieve the purpose of decomposing the low-frequency vibration energy of the pipeline into multiple high-frequency vibration energies.

[0054] In this embodiment, the impedance circuit 221 is a conventional circuit form, which can be composed of resistors, capacitors, and inductors connected in series and parallel, and will not be described in detail here. The field-effect transistor 222 mentioned above can be a metal-oxide-semiconductor field-effect transistor 222; the switching signal generation circuit 223 can be an oscillator with a 555 timer, and the switching signal controls the on / off state of the impedance circuit 221 through the field-effect transistor 222.

[0055] In this embodiment, the semi-active pipeline vibration isolator 100 may also be specially equipped with a pipe clamp 3 for connecting the vibration-isolated pipeline 4, and the pipe clamp 3 is connected to the top end of the aforementioned mover 211.

[0056] In this embodiment, as Figure 1 As shown, the pipe clamp 3 includes a lower pipe clamp seat 31, an upper pipe clamp 32, and a fastening bolt 33. The upper pipe clamp 32 and the lower pipe clamp seat 31 are arranged vertically and connected together, with the vibration-isolated pipe 4 clamped between the upper pipe clamp 32 and the lower pipe clamp seat 31. After the vibration-isolated pipe 4 is clamped between the upper pipe clamp 32 and the lower pipe clamp seat 31, the fastening bolt 33 can be threaded through the side connecting lugs of the upper pipe clamp 32 and the lower pipe clamp seat 31 and then threadedly connected to the threaded hole 2110 at the top of the mover 211.

[0057] In this embodiment, to prevent damage from the vibration isolation pipe 4, a soft gasket 34 is also provided on the inner ring of the pipe clamp 3. The soft gasket 34 can be made of viscoelastic material, and is generally preferably a rubber gasket. Rubber gaskets are provided on the inner rings of both the upper pipe clamp 32 and the lower pipe clamp seat 31. The rubber gaskets are generally fixed to the upper pipe clamp 32 and the lower pipe clamp seat 31 by vulcanization.

[0058] In this embodiment, the elastic element 12 can be a viscoelastic material, such as a rubber block, which can be fixed to the base 11 and the mass block 13 by vulcanization.

[0059] In this embodiment, preferably, side connecting lugs are symmetrically arranged on both sides of the upper clamp 32 and the lower clamp seat 31. Correspondingly, two sets of nonlinear modulation units 2 can be arranged on the mass block 13, and the two movers 211 of the two sets of nonlinear modulation units 2 are symmetrically connected to both sides of the clamp 3, such as... Figure 1 As shown.

[0060] The working principle of the semi-active pipeline vibration isolator 100 described in this embodiment will be explained in detail below.

[0061] First, the pipe clamp 3 is clamped to the vibration isolation pipe 4. The base 11 is fixed to the installation foundation by the connecting bolt 14. The mass block 13 in the middle is connected to the base 11 by the elastic element 12. The mover 211 of the electromagnetic actuator is connected to the pipe clamp 3 by the fastening bolt 33. The outer shell 217 of the electromagnetic actuator is connected to the mass block 13 by the bolt 218.

[0062] During operation, the pipeline system generates vibrations of a certain intensity. This vibration energy is transmitted through the isolated pipe 4, pipe clamp 3, and fastening bolts 33 to the actuator 211 of the electromagnetic actuator. After attenuation and modulation by the electromagnetic actuator and the switching modulation circuit 22, the vibration energy is finally transmitted to the mounting foundation via the mass block 13, elastic element 12, base 11, and connecting bolts 14. The elasticity of the electromagnetic actuator and elastic element 12 enables the isolator to support the pipeline. Simultaneously, the combined effect of the elasticity of the electromagnetic actuator and elastic element 12, along with the inertia of the isolated pipe 4, pipe clamp 3, and intermediate mass block 13, attenuates vibration energy above its natural frequency. The electromagnetic actuator and switching modulation circuit 22 perform nonlinear modulation, converting the low-frequency vibration energy of the pipeline into high-frequency vibration energy, which is then transmitted to the mass block 13. Finally, the mass block 13 and elastic element 12 attenuate this energy, suppressing the transmission of pipeline vibration to the mounting foundation.

[0063] The modulation effect of the electromagnetic actuator and the switching modulation circuit 22 is as follows: Figure 3 , Figure 4As shown, under the action of vibration, the coil 214, which is fixedly connected to the mover 211, will reciprocate in the magnetic circuit composed of the inner magnet 212, the outer magnet 215, and the permanent magnet 216, cutting the magnetic field lines to generate current. The interaction between the current and the magnetic field will generate an interaction force between the mover 211 and the outer shell 217. The coil 214 forms a loop with the field-effect transistor 222 of the switching modulation circuit 22 and the impedance circuit 221. According to the switching signal generated by the switching signal generation circuit 223, the state of the field-effect transistor 222 will repeatedly switch between open and closed, modulating the current in the above loop, thereby modulating the interaction force between the mover 211 and the outer shell 217. For the low-frequency vibration transmitted from the mover 211, the switching modulation circuit 22 will switch the on and off state of the loop several times within one vibration cycle, thereby decomposing the energy of the low-frequency vibration into the energy of multiple high-frequency vibrations, so that the vibration transmitted from the bolt 218 to the mass block 13 has a high-frequency component. Then, the high-frequency vibration can be isolated by the passive vibration isolation unit 1. Figure 4 The topmost diagram represents the low-frequency vibration excitation transmitted from the pipeline to the actuator 21. In this case, the vibration isolation effect of the double-layer vibration isolator is limited. The state switching of the actuator 21 between the pipeline and the mass block 13 is as follows: Figure 4 The intermediate diagram shows that the system can switch between two states (e.g., between high stiffness and low stiffness, or between high damping and low damping) through the control of the switching modulation circuit 22. Through modulation by the actuator 21 (multiple switching), the single low-frequency vibration excitation transmitted by the actuator 21 to the mass block 13 is dispersed into multiple frequency components, thereby reducing the transmission of high-frequency components in the downstream vibration excitation. The downstream vibration variation is as follows... Figure 4 The bottom image is shown in the diagram.

[0064] Therefore, the semi-active pipeline vibration isolator 100 proposed in this technical solution is essentially a semi-active double-layer vibration isolator for pipeline vibration modulation. The upper nonlinear modulation unit 2 is a semi-active vibration isolation element. Its electromagnetic actuator rapidly switches the stiffness, damping, and other transmission characteristics of the electromagnetic actuator through the switching modulation circuit 22 to nonlinearly modulate the vibration propagation path from the isolated pipeline 4 to the mounting foundation, especially for low-frequency vibrations. This disperses the vibration energy below the isolator's natural frequency into the isolator's operating frequency range, thereby controlling the pipeline vibration. Finally, the lower passive vibration isolation unit 1 suppresses the transmission of the modulated vibration. By nonlinearly modulating the vibration energy, the problem of linear vibration isolators being limited by their inherent characteristics is avoided, achieving better low-frequency vibration isolation. Since it only controls the on / off state of the actuator coil and shunt circuit, without inputting energy to the actuator, the above-mentioned double-layer vibration isolator based on nonlinear modulation in this technical solution is more energy-efficient than traditional active vibration isolators.

[0065] In summary, the semi-active pipeline vibration isolator 100 of this technical solution achieves excellent pipeline vibration isolation by nonlinearly modulating pipeline vibration and suppressing the transmission of pipeline vibration to the installation foundation. This semi-active pipeline vibration isolator 100 not only overcomes the problem of limited vibration isolation effect of existing vibration isolators for low-frequency vibration, but also features a nonlinear modulation unit in the upper layer that has the advantages of low price and low energy consumption of traditional semi-active vibration isolators, while the passive vibration isolation unit in the lower layer has the advantages of simple components, small size and low cost of traditional passive vibration isolators. Thus, a vibration isolation system with simple structure, small size, low energy consumption, low cost, good vibration isolation effect and applicability to various vibration conditions is formed, which can meet the characteristics of complex structure, space constraints and high vibration control requirements of existing pipeline systems in buildings, ships and other applications.

[0066] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A semi-active pipeline vibration isolator, characterized in that, include: The nonlinear modulation unit includes an actuator and a switching modulation circuit. The switching modulation circuit is connected to the coil in the actuator to form a loop. The actuator's mover is used to connect to the vibration-isolated pipeline. When the mover transmits low-frequency vibration from the pipeline, the switching modulation circuit can switch the on / off state of the loop several times within one vibration cycle of the low-frequency vibration to perform nonlinear modulation on the low-frequency vibration and decompose the low-frequency vibration into multiple high-frequency vibrations. A passive vibration isolation unit is disposed below the actuator. The passive vibration isolation unit includes a base, an elastic element and a mass block arranged sequentially from bottom to top. The base is used to connect to the mounting foundation, and the mass block is connected to the actuator. The passive vibration isolation unit is used to suppress the high-frequency vibration of the isolated pipeline and the high-frequency vibration formed by the decomposition of the low-frequency vibration.

2. The semi-active pipeline vibration isolator according to claim 1, characterized in that, The actuator is an electric actuator or an electromagnetic actuator.

3. The semi-active pipeline vibration isolator according to claim 2, characterized in that, The actuator is an electromagnetic actuator, which includes: The outer casing, the bottom of which is connected to the mass block; An electromagnetic component is disposed within the housing. The electromagnetic component includes an inner magnet, an outer magnet, a permanent magnet, and a coil. The inner magnet is fitted inside the outer magnet. The permanent magnet is fitted between the inner magnet and the outer magnet. The coil is movably fitted between the inner magnet and the outer magnet, and the coil is located above the permanent magnet. The mover is movably inserted into the inner ring of the inner magnet and connected to the coil. The mover can drive the coil to reciprocate in the magnetic circuit composed of the inner magnet, the outer magnet and the permanent magnet under the action of pipeline vibration, so that the coil cuts the magnetic field lines to generate current. The mover and the outer shell generate an interaction force under the dual action of current and magnetic field.

4. The semi-active pipeline vibration isolator according to claim 3, characterized in that, The moving part and the outer casing are made of stainless steel; or, the moving part and the outer casing are made of carbon fiber.

5. The semi-active pipeline vibration isolator according to claim 3, characterized in that, The moving part has a through hole through which the wire of the coil passes.

6. The semi-active pipeline vibration isolator according to any one of claims 1 to 5, characterized in that, The switching modulation circuit includes an impedance circuit, a field-effect transistor (FET), and a switching signal generation circuit. The impedance circuit, the FET, and the coil are connected to form the loop. The switching signal generation circuit is connected to the FET and can control the FET to switch between an off state and an on state to switch the on / off state of the loop.

7. The semi-active pipeline vibration isolator according to claim 6, characterized in that, The field-effect transistor is a metal-oxide-semiconductor field-effect transistor; the switching signal generation circuit is an oscillator with a 555 timer.

8. The semi-active pipeline vibration isolator according to any one of claims 1 to 5, characterized in that, It also includes a clamp for connecting the vibration-isolated pipeline, the clamp being connected to the top of the mover.

9. The semi-active pipeline vibration isolator according to claim 8, characterized in that, The pipe clamp includes a lower pipe clamp seat, an upper pipe clamp, and a fastening bolt. The upper pipe clamp and the lower pipe clamp seat are connected together, and the fastening bolt passes through the upper pipe clamp and the lower pipe clamp seat in sequence and is threadedly connected to the moving part.

10. The semi-active pipeline vibration isolator according to claim 8, characterized in that, The mass block is provided with two sets of nonlinear modulation units, and the two movers of the two sets of nonlinear modulation units are symmetrically connected to both sides of the pipe clamp.

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