Series passive-active hybrid vibration isolator for maintaining air gap spacing of electromagnetic shaker

Abstract

The application discloses a series type active-passive hybrid vibration isolator for keeping the air gap spacing of an electromagnetic exciter, comprising a control force output main air bag, an electromagnetic exciter arranged in the control force output main air bag and a height adjustment auxiliary air bag, and the control force output main air bag is connected with the height adjustment auxiliary air bag in series through a movable cover plate. While not affecting the passive vibration isolation performance and the active control force output performance, the adjustable air pressure in the air bag is utilized to design the auxiliary air bag and the pressure regulating scheme connected in series, so that the air gap spacing between the armature and the iron core of the internal exciter is kept, the active-passive hybrid vibration isolator can be applied to the scene where the installation spacing changes greatly in real time during work, the use range is greatly expanded, and technical support is provided for accelerating the engineering practicability of the active vibration control technology.

Description

Technical Field

[0001] This invention belongs to the field of active mechanical vibration control technology, specifically relating to a series active-passive hybrid vibration isolator that maintains the air gap spacing of an electromagnetic exciter. Background Technology

[0002] Active vibration control technology plays an irreplaceable role in the field of precision control of mechanical equipment. Actuators and exciters, as output components of the control system, directly affect the overall performance. Installing exciters and passive vibration isolators in parallel between the vibration source equipment and the controlled structure is a long-standing and widely used configuration. In recent years, hybrid active-passive vibration isolators have been developed, integrating airbag passive vibration isolators with exciters or actuators. Their co-location configuration offers advantages such as small size, low control force requirements, and low difficulty in upgrading from a pure passive vibration isolation system to a hybrid vibration isolation system.

[0003] The active-passive hybrid vibration isolator, which integrates an electromagnetic exciter, also possesses outstanding advantages such as good low-frequency output force characteristics, high output force density, and low heat generation. The electromagnetic exciter consists of components such as a permanent magnet, a coil, an armature, and an iron core. The permanent magnet provides static magnetic flux, while the coil, when energized, provides alternating magnetic flux. The two work together on the highly permeable armature and iron core to form a strong AC / DC coupling attraction force, which is then output outward.

[0004] In existing hybrid active-passive vibration isolators, during normal operation, the armature and core of the electromagnetic exciter are fixedly connected to the upper and lower cover plates of the airbag vibration isolator, respectively. Therefore, the air gap distance of the exciter changes by the same amount as the installation height of the airbag vibration isolator. However, the output force of the electromagnetic exciter is closely related to the air gap distance between its armature and core, which can be represented by an approximate formula (1), where f m Given the electromagnetic output force, A and B are structure-related constants, and ΔB is the change in air gap distance, it can be seen that the exciter output force f is... m It decreases rapidly as the air gap spacing ΔB increases.

[0005]

[0006] During the operation of a vibration control system, if the installation height of the airbag isolator is excessively increased, resulting in an excessively large air gap between the internal exciter, it will severely reduce the output force of the exciter, as shown in equation (1). On the other hand, if the installation height of the airbag isolator is excessively reduced, the armature of the exciter will come into contact with the iron core, significantly increasing the stiffness between the armature and the controlled structure. The magnetic force acting on the iron core and the force directly applied to the iron core by the armature due to contact will be superimposed, causing the external output force of the exciter to approach zero. Both of these situations will lead to the failure of the active vibration control function. Therefore, during the operation of an active vibration control system, existing technologies often require a relatively precise positional relationship between the vibration source equipment and the controlled structure.

[0007] However, in engineering practice, scenarios where the vertical installation spacing of vibration isolators changes over a wide range in real time are constantly emerging, severely limiting the application range of hybrid active and passive vibration isolators that integrate electromagnetic exciters.

[0008] To solve this problem, some engineers have proposed a technical approach of adding an electromechanical lifting mechanism inside the airbag isolator. However, the static attraction between the armature and the iron core is generally around 1000N, and the internal space of the airbag is small, making it difficult for a small-sized electromechanical structure to generate sufficient driving force to maintain the air gap. Furthermore, complex electromechanical structures have high maintenance requirements and low reliability. Summary of the Invention

[0009] The present invention aims to overcome the above-mentioned technical problems by providing a series active-passive hybrid vibration isolator that maintains the air gap spacing of the electromagnetic exciter, thereby solving the technical defect that the internal exciter cannot work properly when the vertical installation spacing of the vibration isolator changes over a wide range.

[0010] To achieve the above objectives, the present invention provides a series-type active-passive hybrid vibration isolator that maintains the air gap spacing of an electromagnetic vibrator, comprising a main control force output airbag, an electromagnetic vibrator placed inside the main control force output airbag, and a height-adjustable auxiliary airbag, wherein the main control force output airbag is connected in series with the height-adjustable auxiliary airbag via a movable cover plate.

[0011] Furthermore, the top opening of the main control force output airbag is fixedly sealed with a main airbag upper cover plate, the bottom opening of the main control force output airbag is connected and sealed to the top opening of the height-adjustable auxiliary airbag through a movable cover plate, and the bottom opening of the height-adjustable auxiliary airbag is fixedly sealed with an auxiliary airbag lower cover plate.

[0012] Furthermore, the electromagnetic vibrator includes a vibrator core with a coil and a vibrator armature arranged opposite to each other; the main airbag cover plate is fixedly connected to the vibrator armature, and the vibrator core with a coil is fixedly connected to the movable cover plate.

[0013] Furthermore, the electromagnetic vibrator includes a vibrator core with a coil and a vibrator armature arranged opposite to each other; the main airbag cover plate is fixedly connected to the vibrator core with a coil, and the vibrator armature is fixedly connected to the movable cover plate.

[0014] Furthermore, the feature is that the exciter core with coil is connected to the power drive device.

[0015] Furthermore, the main control force output airbag and the secondary height adjustment airbag are respectively connected to the high-pressure gas control device through gas pipelines.

[0016] Compared with the prior art, the advantages of the present invention are as follows: While not affecting the passive vibration isolation performance and the active control force output performance, the present invention utilizes the adjustable air pressure inside the airbag to design a series-connected auxiliary airbag and pressure adjustment scheme, thereby maintaining the air gap distance between the armature and the iron core of the internal exciter. This allows the active-passive hybrid vibration isolator described in the present invention to be applied to scenarios where the installation spacing changes significantly in real time during operation, greatly expanding the scope of application and providing technical support for accelerating the engineering application of active vibration control technology.

[0017] By adjusting the dynamic stiffness, the auxiliary airbag can act as a low-pass filter to attenuate the high-frequency output force noise of the exciter, thereby improving the actual performance of the active vibration control technology. Due to the addition of the auxiliary airbag, the mutual influence between different active-passive hybrid vibration isolators in the same system is reduced, facilitating the implementation of in-situ vibration control. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the present invention;

[0019] Figure 2 This is a simplified diagram of the vertical force analysis of the active-passive hybrid vibration isolator of the present invention;

[0020] Figure 3 This is the circuit diagram of the force analysis of this invention after electromechanical analogy;

[0021] Figure 4 The above is a diagram showing the amplitude-frequency response of the output force of the active-passive hybrid vibration isolator relative to the electromagnetic excitation force in an example.

[0022] Figure 5 The above is a cross-point admittance amplitude-frequency response diagram of the output force of the active-passive hybrid vibration isolator relative to the electromagnetic excitation force in the example.

[0023] Figure 6 The output force is shown as the amplitude-frequency response diagram relative to the electromagnetic force in the example. Detailed Implementation

[0024] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0025] like Figure 1The series-type active-passive hybrid vibration isolator shown, which maintains the air gap distance of the electromagnetic exciter, includes a main control force output airbag 1, an electromagnetic exciter placed inside the main control force output airbag 1, and a height-adjustable auxiliary airbag 7. The electromagnetic exciter includes an exciter core 5 with a coil and an exciter armature 4 arranged opposite to each other. The top opening of the main control force output airbag 1 is fixedly sealed with a main airbag upper cover plate 2. The bottom opening of the main control force output airbag 1 is connected and sealed to the top opening of the height-adjustable auxiliary airbag 7 through a movable cover plate 3. The bottom opening of the height-adjustable auxiliary airbag 7 is fixedly sealed with an auxiliary airbag lower cover plate 8. The main airbag upper cover plate 2 is fixedly connected to the exciter armature 4 (or the exciter core 5 with a coil), and the exciter core 5 with a coil (or the exciter armature 4) is fixedly connected to the movable cover plate 3. The exciter core 5 with coil is connected to the power drive device 10. The main control force output airbag 1 and the height adjustment auxiliary airbag 7 are respectively connected to the high-pressure gas control device 9 through gas pipelines. After the internal air pressure of the main control force output airbag 1 and the height adjustment auxiliary airbag 7 is regulated by the high-pressure gas control device 9, the height of the movable cover plate 3 changes accordingly.

[0026] The resultant force formed by the static force of the main airbag's internal air pressure acting on the effective area S1 of the movable cover, and the static force of the auxiliary airbag's internal air pressure acting on the effective area S2 of the movable cover, plus the static magnetic attraction F generated between the armature and the iron core of the electromagnetic vibrator, is combined with the static magnetic attraction F generated between the armature and the iron core of the electromagnetic vibrator. m Balance. The series-type active-passive hybrid vibration isolator adjusts the height of the auxiliary airbag by inflating and deflating the internal gas pressure. The total height is equal to the height of the main airbag for controlling the force output plus the height of the auxiliary airbag for adjusting the height. When the total height changes in real time due to installation conditions, the pressure of the main and auxiliary airbags is adjusted simultaneously to ensure that the resultant force caused by the gas on both sides of the movable cover plate is always balanced with the static magnetic attraction force. Therefore, the height of the main airbag for controlling the force output can be kept constant, thereby maintaining a constant air gap between the armature and the core of the vibrator connected in parallel with the main airbag for controlling the force output.

[0027] Specifically, let the pressure inside the main control airbag be p1 and the pressure inside the height-adjusting auxiliary airbag be p2. Under certain air gap conditions, when a static magnetic field and an alternating magnetic field act on the iron core (or armature, depending on the installation) fixed to the movable cover, the resulting DC component of the attractive force is F. m Clearly, by adjusting the pressure of the main and auxiliary airbags, the resultant force acting on the effective areas S1 and S2 of their respective movable cover plates is equal to F. m Equal in size and opposite in direction, i.e., F mWhen p1S1 = p2S2, the movable cover plate is in static equilibrium, maintaining its spatial position and thus keeping the air gap spacing of the electromagnetic vibrator constant. On the other hand, the active control force requirement is relatively small, so the AC component of the electromagnetic force is smaller than its DC component, and the auxiliary airbag has extremely high dynamic stiffness. Therefore, the movable cover plate hardly moves when the vibrator is working normally, maintaining a state of static equilibrium.

[0028] In actual operation, when the vertical installation spacing of the vibration isolators decreases, the total height of the active and passive vibration isolators decreases, thus the heights of the main and auxiliary airbags connected in series also decrease accordingly. The internal pressures p1 and p2 of the main and auxiliary airbags increase due to the shrinkage of the cavity volume, and the effective areas on both sides of the movable cover plate also change to varying degrees. At this time, the internal pressures of the main and auxiliary airbags can be adjusted as needed (generally, the auxiliary airbag is depressurized) so that the resultant force acting on the effective areas S1′ and S2′ of their respective movable cover plates can provide a static driving force opposite to the rated attractive force inside the vibrator, until the air gap distance returns to its rated value. At this point, the height of the main airbag is the same as before, and the shape of the main airbag, i.e., its effective area, is the same as before. Therefore, the thrust p1S1 of the air pressure inside the main airbag acting on the movable cover plate is the same as before, and the supporting force p2′S2′ of the air pressure inside the auxiliary airbag acting on the movable cover plate is also the same as before (the effective area S2′ increases, while the pressure p2′ is reduced by adjustment). m =p1S1-p2′S2′ is also consistent with the original, so the air gap spacing of the electromagnetic vibrator can be kept constant.

[0029] Conversely, when the vertical installation spacing of the vibration isolators increases, the total height of the active and passive vibration isolators increases, thus the heights of the main and auxiliary airbags connected in series also increase accordingly. The internal pressures p1 and p2 of the main and auxiliary airbags decrease due to the expansion of the cavity volume, and the effective areas on both sides of the movable cover plate also change to varying degrees. At this time, the internal pressures of the main and auxiliary airbags can be adjusted as needed (generally, the auxiliary airbag is pressurized), so that the resultant force acting on the effective areas S1′ and S2′ of their respective movable covers can provide a static driving force opposite to the rated attractive force inside the vibrator, until the air gap distance returns to its rated value. At this point, the height of the main airbag is the same as before, and the shape of the main airbag, i.e., its effective area, is the same as before. Therefore, the thrust p1S1 of the air pressure inside the main airbag acting on the movable cover plate is the same as before, and the supporting force p2′S2′ of the air pressure inside the auxiliary airbag acting on the movable cover plate is also the same as before (the effective area S2′ decreases, while the pressure p2′ is increased under control). m =p1S1-p2′S2′ is also consistent with the original, thus maintaining the constant air gap spacing of the electromagnetic exciter.

[0030] Vibration active control technology focuses on the actuator's origin admittance and cross-point admittance, which characterize the control efficiency and mutual influence of the controlled point, respectively. Considering common engineering scenarios involving vertical forces and double vibration isolators supporting a single mass block and fixed to another mass block, the dynamic model is as follows: Figure 2 As shown. Where M represents the machine equipment and controlled structure carried by the vibration isolator; for simplicity, their masses are assumed to be the same; m is the sum of the masses of the movable cover plate and its fixed exciter assembly; k1 is the dynamic stiffness of the main airbag; k2 is the dynamic stiffness of the auxiliary airbag; K is the stiffness between the controlled structure and the inertial frame; f m This is the AC component of the electromagnetic driving force generated after the exciter is energized. This force acts simultaneously on the armature and the iron core, and is equal in magnitude but opposite in direction.

[0031] If we analogize mass, the reciprocal of stiffness, force, and velocity to capacitance, inductance, current, and voltage, respectively, then for... Figure 2 The "circuit diagram" after electromechanical analogy is as follows: Figure 3 As shown.

[0032] Based on the actual conditions of existing equipment in engineering practice, the main parameters in the embodiment are assumed as follows: the air pressure inside the main airbag is p1 = 2 MPa, the air pressure inside the auxiliary airbag is p2 = 1.9 MPa, and the effective areas of the movable covers of the main and auxiliary airbags are equal and S. e =0.01m 2 The static attraction force between the armature and the core of the vibrator is F. m =1000N, the mass of the movable cover and its fixed parts is m=20kg, the mass of the load-bearing mass and the mass of the controlled structure is M=1.6e4kg, the stiffness of the main airbag is k1=3e6N / m, the stiffness of the auxiliary airbag is k2=6e6N / m, and the stiffness between the controlled structure and the inertial frame is K=1e8N / m.

[0033] Clearly, through the differential pressure control scheme conceived in this invention, the static attraction between the vibrator armature and the iron core can be balanced by the driving force of the auxiliary airbag movable cover plate, i.e., F m =(p1-p2)S e =1000N, thus keeping the air gap distance constant.

[0034] Regarding the active control force output capability, the output force f of the hybrid vibration isolator described in this invention when directly connected to the inertial frame is... s Relative alternating electromagnetic driving force f m The amplitude-frequency response is as follows Figure 4 , 5As shown in the figure. Clearly, the origin admittance exhibits significant attenuation above 1kHz, and the cross-point admittance is much smaller than the origin admittance in the commonly used operating frequency range (20-90Hz), indicating that the active-passive hybrid vibration isolator has low-pass filtering characteristics, and their mutual influence is minimal. The amplitude-frequency response of the force output from the vibration isolator to the controlled structure relative to the electromagnetic force is as follows: Figure 6 As shown, the frequency response is relatively flat within the commonly used operating frequency band (20-90Hz). In fact, the operating frequency band can be extended by adjusting the vibration isolator parameters, but the characteristics shown in this embodiment, such as flat output force response in the operating frequency band, high-frequency filtering capability, and minimal mutual influence between different vibration isolators, will be retained.

[0035] This invention adds a secondary airbag below the main airbag, so the actuator output force is low-pass filtered before being transmitted to the controlled device, which reduces the impact of high-frequency interference from the actuator. Overall, compared with the prior art, this invention has the following advantages:

[0036] Without affecting the passive vibration isolation performance and the active control force output performance, the auxiliary airbags and pressure adjustment scheme connected in series are designed by taking advantage of the adjustable air pressure inside the airbag. This achieves the maintenance of the air gap between the armature and the iron core of the internal exciter, so that the active-passive hybrid vibration isolator described in this invention can be applied to scenarios where the installation spacing changes significantly in real time during operation. This greatly expands the scope of application and provides technical support for accelerating the engineering application of active vibration control technology.

[0037] By adjusting the dynamic stiffness, the auxiliary airbag can act as a low-pass filter to attenuate the high-frequency output force noise of the exciter, thereby improving the actual performance of the active vibration control technology. Due to the addition of the auxiliary airbag, the mutual influence between different active-passive hybrid vibration isolators in the same system is reduced, facilitating the implementation of in-situ vibration control.

Claims

1. A series-type active-passive hybrid vibration isolator that maintains the air gap spacing of an electromagnetic exciter, characterized in that: It includes a main airbag for controlling force output (1), an electromagnetic vibrator placed inside the main airbag for controlling force output (1), and a secondary airbag for height adjustment (7). The main airbag for controlling force output (1) is connected in series with the secondary airbag for height adjustment (7) through a movable cover plate (3). The top opening of the main airbag (1) for controlling force output is fixedly sealed with a main airbag upper cover plate (2), and the bottom opening of the main airbag (1) for controlling force output is connected and sealed to the top opening of the height-adjustable auxiliary airbag (7) through a movable cover plate (3). The bottom opening of the height-adjustable auxiliary airbag (7) is fixedly sealed with an auxiliary airbag lower cover plate (8). The electromagnetic vibrator includes a vibrator core (5) with a coil and a vibrator armature (4) arranged opposite to each other. The main airbag upper cover plate (2) is fixedly connected to the vibrator armature (4), and the vibrator core (5) with a coil is fixedly connected to the movable cover plate (3). The main airbag (1) for controlling force output and the auxiliary airbag (7) for height adjustment are respectively connected to the high-pressure gas control device (9) through gas pipelines.

2. The series-type active-passive hybrid vibration isolator that maintains the air gap spacing of the electromagnetic exciter according to claim 1, characterized in that: The electromagnetic vibrator includes a vibrator core (5) with coils and a vibrator armature (4) arranged opposite to each other; the main airbag cover plate (2) is fixedly connected to the vibrator core with coils, and the vibrator armature (4) is fixedly connected to the movable cover plate (3).

3. The series-type active-passive hybrid vibration isolator that maintains the air gap spacing of the electromagnetic exciter according to claim 1 or 2, characterized in that: The exciter core (5) with coil is connected to the power drive device (10).

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