Active vibration isolation system with servo valve

Abstract

The invention belongs to the technical field of damping devices, and provides an active vibration isolation system with a servo valve. The device comprises a working platform and a mounting platform below the working platform, an air bag cavity is formed between the mounting platform and the working platform, the air bag cavity is connected with the working platform and the mounting platform, a first electromagnetic actuator is arranged in the air bag cavity, a triggering device is arranged at the stroke tail end of the first electromagnetic actuator, and the air bag cavity is provided with an air inlet hole and an exhaust hole; the trigger device is connected with the air inlet and the exhaust hole. The electromagnetic actuator is adopted to generate reverse anti-vibration force, signals sent by the system are matched with the air bag unit to carry out active compensation, and dynamic loads are adapted through gas-electricity hybrid; an air bag-spring mixed positive and negative stiffness mechanism is adopted for parallel coupling to form a near-zero stiffness area for a load with large dynamic fluctuation; the pneumatic-electric hybrid mechanism expands the application range of the same stroke of the electromagnetic actuator and covers a higher vibration isolation bandwidth.

Description

Technical Field

[0001] The present invention relates to the technical field of shock absorbing devices, and in particular to an active vibration isolation system with a servo valve. Background Art

[0002] Traditional airbag isolators mostly rely on mechanical leveling valves or passive damping structures, such as the combination of a leveling valve and an airbag. They have problems such as slow response speed, response delay >100ms, low adjustment accuracy, and adjustment error of up to ±5%FS, making it difficult to meet submicron vibration isolation requirements. Most airbag stiffness isolators are designed for a single vibration isolation object. Once the isolator is manufactured, the structural parameters cannot be changed. When the isolation quality changes, such as overload or underload, the isolator no longer has the quasi-zero stiffness characteristic, and the vibration isolation performance decreases. Prior art CN119778420A provides a three-degree-of-freedom quasi-zero stiffness isolator, including a table, a base, a baffle, and a vertical isolator. The baffle is vertically welded around the top of the base, the middle of the bottom of the table is vertically connected to the vertical isolator, and horizontal isolators are vertically connected between the middle of the side surfaces of the table and the baffle. Existing technologies can achieve quasi-zero stiffness in all three degrees of freedom (DOF) in the vertical and horizontal directions, enabling vibration control from 0.1Hz to 300Hz. However, the pressure regulating valve is susceptible to air pressure fluctuations under loads with large dynamic fluctuations, resulting in reduced vibration isolation performance. Furthermore, traditional airbag isolators also suffer from poor adaptability to loads with large dynamic fluctuations and limited isolation bandwidth. The inventors believe that there is significant room for improvement in this existing technology. Summary of the Invention

[0003] The present invention aims to provide an active vibration isolation system that uses an electromagnetic actuator to generate a reverse anti-vibration force. This system then uses signals from the system to coordinate with the airbag unit for active compensation, adapting to dynamic loads through a pneumatic-electric hybrid system. Furthermore, a parallel coupling of positive and negative stiffness mechanisms, combining an airbag and spring, creates a near-zero stiffness zone for loads with large dynamic fluctuations. The pneumatic-electric hybrid mechanism expands the electromagnetic actuator's adaptability within the same stroke range, covering a wider vibration isolation bandwidth.

[0004] An active vibration isolation system with a servo valve includes a working platform and a mounting platform below the working platform. An airbag cavity is provided between the mounting platform and the working platform, the airbag cavity connects the working platform and the mounting platform, a first electromagnetic actuator is provided inside the airbag cavity, a trigger device is provided at the end of the stroke of the first electromagnetic actuator, the airbag cavity is provided with an air inlet and an exhaust hole, and the trigger device is connected to the air inlet and the exhaust hole. When the load exceeds the reverse anti-vibration force range that the first electromagnetic actuator and the initial airbag cavity can provide, the first electromagnetic actuator reaches the end of its stroke, the detection end and the trigger end of the first electromagnetic actuator come into contact, and the trigger device sends a signal to control the air intake of the airbag cavity to increase the stiffness of the airbag cavity, so that the first electromagnetic actuator and the airbag cavity can provide greater reverse anti-vibration force and increase the load range that can be adapted. When the dynamic load decreases, the detection end and the trigger end of the first electromagnetic actuator stop contacting, and the trigger device stops sending a signal, controlling the air discharge of the airbag cavity, reducing the stiffness of the airbag cavity, reducing the reverse anti-vibration force of the first electromagnetic actuator and the airbag cavity, and increasing the range of vibration suppression bandwidth that can be adapted. The gas-electric hybrid mechanism expands the adaptability range of the electromagnetic actuator within the same stroke, covering a higher vibration isolation bandwidth. A sensor is provided inside the trigger device, which can be a pressure sensor or a proximity switch.

[0005] Preferably, a second electromagnetic actuator is provided outside the airbag cavity, and the second electromagnetic actuator includes a fixed end and a movable end. The movable end of the second electromagnetic actuator is connected to the bottom of the working platform, and the fixed end of the second electromagnetic actuator is connected to the installation platform.

[0006] Preferably, at least two second electromagnetic actuators are positioned outside the airbag cavity, evenly distributed around the circumference. These second electromagnetic actuators provide the fundamental vibration-resistance and vibration-suppression bandwidth of this application. This even distribution ensures that vibrations at every point on the work platform are effectively absorbed, ensuring consistent vibration-resistance across all locations on the work platform.

[0007] Preferably, the first electromagnetic actuator includes a trigger end and a detection end. The detection end of the first electromagnetic actuator is provided on the top surface of the mounting platform, and the trigger end of the first electromagnetic actuator is provided on the bottom surface of the working platform. A trigger device is provided on the side of the detection end of the first electromagnetic actuator near the trigger end. The distance between the mounting platform and the working platform varies for different loads. When the load exceeds the tolerance range of the initial state of this application, the distance between the mounting platform and the working platform is minimized. The trigger end of the first electromagnetic actuator on the bottom surface of the working platform contacts the trigger device of the detection end of the first electromagnetic actuator on the top surface of the mounting platform. The trigger device sends a signal, which appropriately increases the stiffness of the airbag cavity, enabling the first electromagnetic actuator and the airbag cavity to withstand higher loads and increase the vibration suppression bandwidth that can be adapted.

[0008] Preferably, the airbag cavity includes a first and second annular enclosure. The first enclosure extends longitudinally from the bottom of the working platform to the mounting platform, while the second enclosure extends vertically from the top of the mounting platform to the working platform. The first and second enclosures are arranged alternately. The first and second enclosures separate the interior space of the airbag cavity, complicating the gas flow path within the cavity, improving internal damping, broadening the vibration suppression bandwidth, and enhancing vibration isolation effectiveness.

[0009] Preferably, the height of the trigger device matches the distance from the end of the first panel to the mounting platform. As the load or vibration amplitude increases, the narrower the width of the new gas flow path formed by the first and second panels, the greater the damping of the gas flow. If the gas flow path formed by the first and second panels is too narrow, the stiffness of the airbag cavity will increase, raising the natural frequency of the vibration isolation system and causing low-frequency vibrations to fall into the resonance zone. Therefore, the height of the trigger device needs to be greater than the distance from the end of the first panel to the mounting platform to limit the increase in stiffness of the airbag cavity.

[0010] Preferably, the second enclosure is located outside the first enclosure. An elastic member is provided on the outer wall of the outer ring of the first enclosure, connecting the first and second enclosures. The elastic member between the airbag cavity and the enclosure forms a parallel mechanism of positive and negative stiffness, creating a near-zero stiffness zone and enhancing the isolation effect against subtle, low-frequency vibrations.

[0011] Preferably, the elastomer is conical, with the small end of the cone connected to the first enclosure, and the large end of the cone connected to the second enclosure. Multiple elastomers connect the first enclosure and the second enclosure to form a seal for the airbag cavity, ensuring the gas sealing effect of the airbag cavity, and the airbag cavity has a shock-absorbing effect. The stacking of conical elastomers can form a disc spring. During the relative movement of the first enclosure and the second enclosure, the ratio of the height to the thickness of the elastomer is maintained at >3, and the conical elastomer is in a negative stiffness state. The elastomer between the airbag cavity and the enclosure forms a positive stiffness and negative stiffness parallel mechanism to synthesize a near-zero stiffness zone, thereby improving the vibration isolation effect for slight low-frequency vibrations. When the descending distance of the first enclosure is small, the greater the ratio of the height to the thickness of the elastomer, the smaller the negative stiffness can be provided, making the synthetic stiffness closer to zero stiffness, reducing the natural frequency of the vibration isolation system, making the range of the resonance zone smaller, and improving the vibration isolation effect.

[0012] Preferably, a servo valve is provided on the outer wall of the second enclosure, which also includes an exhaust hole and an air inlet hole. The trigger device is connected to the exhaust hole and the air inlet hole via the servo valve. The trigger device signal is converted by the servo valve into a signal that controls whether to allow air to enter and exit the airbag cavity and the gas circulation rate, thereby controlling the opening of the exhaust hole and the air inlet hole to achieve millisecond-level vibration suppression.

[0013] Preferably, the trigger device is a platform, with the large end of the platform connected to the detection end of the first electromagnetic actuator, and the small end of the platform located at the end of the travel of the trigger end of the first electromagnetic actuator. When the load on the work platform fluctuates significantly, especially when the load suddenly increases, the trigger end of the first electromagnetic actuator may rapidly approach the detection end and potentially impact the trigger device. The trigger device being a platform can evenly distribute the impact stress, preventing damage to the trigger device and / or the detection end.

[0014] The present invention solves the problems that the airbag is prone to produce air pressure fluctuations under loads with large dynamic fluctuations, resulting in a decrease in vibration isolation performance; the problem that the load adaptability to large dynamic fluctuations is poor and the vibration isolation bandwidth is limited, and has the following beneficial effects: complicating the gas flow channel inside the airbag cavity, improving the internal damping of the airbag cavity, increasing the range of the vibration suppression bandwidth that can be adapted, and improving the vibration isolation effect; the elastic body between the airbag cavity and the enclosure forms a positive stiffness and negative stiffness parallel mechanism to synthesize a near-zero stiffness zone, thereby improving the vibration isolation effect on micro-amplitude low-frequency vibrations and achieving high-precision vibration suppression; the signal of the trigger device at the end of the stroke of the first electromagnetic actuator is used to control whether the airbag cavity performs air intake, exhaust and gas circulation rate signals through the servo valve, thereby achieving millisecond-level vibration suppression. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely exemplary, and those skilled in the art can, without inventive effort, derive other implementation drawings based on the provided drawings.

[0016] Figure 1 It is a structural diagram of an active vibration isolation system with a servo valve; Figure 2 It is a front view of an active vibration isolation system with a servo valve; Figure 3 AA cross-sectional view of an active vibration isolation system with a servo valve; Figure 4 This is a BB cross-sectional view of an active vibration isolation system with a servo valve; Figure 5 The CC cross-sectional view of an active vibration isolation system with a servo valve; Figure 6 This is a DD cross-sectional view of an active vibration isolation system with a servo valve; Figure 7 This is a partial enlarged view between the first enclosure and the second enclosure.

[0017] Legend: 1 working platform; 2 mounting platform; 3 second electromagnetic actuator; 31 moving end; 32 fixed end; 4 first electromagnetic actuator; 41 trigger end; 42 detection end; 43 trigger device; 5 airbag cavity; 51 first enclosure; 52 second enclosure; 6 air inlet; 7 exhaust hole; 8 elastomer; 9 servo valve. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0019] Example 1 Combine Figure 1 and Figure 2 As shown, an active vibration isolation system with a servo valve 9 includes a work platform 1 and a mounting platform 2 below the work platform 1. An airbag cavity 5 is provided between the mounting platform 2 and the work platform 1. The airbag cavity 5 connects the work platform 1 and the mounting platform 2. A second electromagnetic actuator 3 is provided outside the airbag cavity 5. The second electromagnetic actuator 3 includes a fixed end 32 and a movable end 31. The movable end 31 of the second electromagnetic actuator 3 is connected to the bottom of the work platform 1, and the fixed end 32 of the second electromagnetic actuator 3 is connected to the mounting platform 2. The outer wall of the second enclosure 52 is provided with a servo valve 9. The second outer wall is also provided with an exhaust hole 7 and an air inlet hole 6. A trigger device 43 is connected to the exhaust hole 7 and the air inlet hole 6 through the servo valve 9. The signal from the trigger device 43 is converted by the servo valve 9 into a signal that controls whether the airbag cavity 5 is to be inhaled, exhausted, and the gas circulation rate, thereby controlling the opening of the exhaust hole 7 and the air inlet hole 6 to achieve millisecond-level vibration suppression.

[0020] Two second electromagnetic actuators 3 are installed outside the airbag cavity 5, evenly distributed around the circumference. These second electromagnetic actuators 3 provide the fundamental vibration damping force and vibration suppression bandwidth required by this application. This even distribution ensures that vibrations at all points on the work platform 1 are effectively absorbed, ensuring consistent vibration damping across all locations on the work platform 1. In this embodiment, both the first electromagnetic actuator 4 and the second electromagnetic actuator 3 are voice coil motors.

[0021] like Figure 5 and Figure 6As shown, a first electromagnetic actuator 4 is provided inside the airbag cavity 5, a trigger device 43 is provided at the end of the stroke of the first electromagnetic actuator 4, the airbag cavity 5 is provided with an air inlet 6 and an exhaust hole 7, and the trigger device 43 is connected to the air inlet 6 and the exhaust hole 7. When the load exceeds the reverse anti-vibration force range that can be provided by the first electromagnetic actuator 4 and the initial airbag cavity 5, the first electromagnetic actuator 4 reaches the end of its stroke, the detection end 42 of the first electromagnetic actuator 4 contacts the trigger end 41, and the trigger device 43 sends a signal to control the airbag cavity 5 to increase the stiffness of the airbag cavity 5, so that the first electromagnetic actuator 4 and the airbag cavity 5 can provide greater reverse anti-vibration force and increase the load range that can be adapted. In this embodiment, the load fluctuation is increased by ±20%; when the dynamic load decreases, the detection end 42 of the first electromagnetic actuator 4 stops contacting the trigger end 41, and the trigger device 43 stops sending a signal, controlling the airbag cavity 5 to release air, reducing the stiffness of the airbag cavity 5, reducing the reverse anti-vibration force of the first electromagnetic actuator 4 and the airbag cavity 5, and increasing the vibration suppression bandwidth that can be adapted. In this embodiment, full frequency band coverage of 0.1 to 2000 Hz is achieved, with a low-frequency band (<10 Hz) transmission rate of ≤5% and a high-frequency band (100 Hz) amplitude attenuation of ≥90%. In this embodiment, a sensor is provided inside the trigger device 43 , and the sensor is a pressure sensor.

[0022] like Figure 6 As shown, the first electromagnetic actuator 4 includes a trigger end 41 and a detection end 42. The detection end 42 of the first electromagnetic actuator 4 is provided on the top surface of the mounting platform 2, and the trigger end 41 of the first electromagnetic actuator 4 is provided on the bottom surface of the working platform 1. A trigger device 43 is provided on the side of the detection end 42 of the first electromagnetic actuator 4 close to the trigger end 41. For different loads, the distance between the mounting platform and the working platform 1 is different. When the load exceeds the tolerance range of the initial state of this application, the distance between the mounting platform 2 and the working platform 1 is the smallest. The trigger end 41 of the first electromagnetic actuator 4 on the bottom surface of the working platform 1 contacts the trigger device 43 of the detection end 42 of the first electromagnetic actuator 4 on the top surface of the mounting platform 2. The trigger device 43 sends a signal, which appropriately increases the stiffness of the airbag cavity 5, so that the first electromagnetic actuator 4 and the airbag cavity 5 can provide a range of higher loads and increase the vibration suppression bandwidth that can be adapted.

[0023] like Figure 3 and Figure 4As shown, the airbag cavity 5 includes a first and second annular panels 51, 52. The first panel 51 extends longitudinally from the bottom of the work platform 1 to the mounting platform 2, while the second panel 52 extends vertically from the top of the mounting platform 2 to the work platform 1. The first and second panels 51, 52 are arranged in an alternating pattern. The use of the first and second panels 51, 52 to separate the interior space of the airbag cavity 5 complicates the gas flow path within the cavity 5, improves internal damping, expands the vibration suppression bandwidth, and enhances the vibration isolation effect.

[0024] like Figure 6 As shown, the trigger device 43 is a platform. The large end of the platform is connected to the detection end 42 of the first electromagnetic actuator 4, and the small end of the platform is located at the end of the travel of the trigger end 41 of the first electromagnetic actuator 4. When the load on the work platform 1 fluctuates significantly, especially when the load suddenly increases, the trigger end 41 of the first electromagnetic actuator 4 quickly approaches the detection end 42, potentially striking the trigger device 43. The trigger device 43 is a platform that evenly distributes the impact stress, preventing damage to the trigger device 43 and / or the detection end 42. The height of the trigger device 43 matches the distance from the end of the first enclosure 51 to the mounting platform 2. When the load increases or the vibration amplitude increases, the smaller the width of the new gas flow channel formed by the first enclosure 51 and the second enclosure 52, the greater the damping of the gas flow; if the gas flow channel formed by the first enclosure 51 and the second enclosure 52 is too small, the gas flow is blocked or even cannot flow, and the internal pressure of the airbag cavity 5 increases, thereby increasing the stiffness of the airbag cavity 5 and the natural frequency of the vibration isolation system, so that the low-frequency vibration falls into the resonance zone. Therefore, the height of the trigger device 43 needs to be greater than the distance from the end of the first enclosure 51 to the mounting platform 2 to limit the increase in the stiffness of the airbag cavity 5.

[0025] Combine Figures 3 to 7 As shown, the active vibration isolation system includes two first panels 51 and three second panels 52. The second panels 52 are located outside the first panels 51, and the first and second panels 51, 52 are arranged alternately. The outer walls of the outer ring of first panels 51 are provided with elastic bodies 8, which connect the first and second panels 51, 52. The elastic bodies 8 between the airbag cavity 5 and the panels form a parallel mechanism of positive and negative stiffness, synthesizing a near-zero stiffness zone, improving the isolation effect against small, low-frequency vibrations and achieving vibration suppression at the 0.1μm level.

[0026] like Figure 7As shown, the elastic body 8 is conical, with the small end of the cone connected to the first enclosure 51 and the large end of the cone connected to the second enclosure 52. The elastic body 8 connects the first enclosure 51 and the second enclosure 52 to form a seal for the airbag cavity 5. The stacked conical elastic bodies 8 can form a disc spring. During the relative movement of the first enclosure 51 and the second enclosure 52, the ratio of the height to the thickness of the elastic body 8 is maintained at >3, and the elastic body 8 is in a negative stiffness state. The elastic body 8 between the airbag cavity 5 and the enclosure forms a parallel mechanism of positive and negative stiffness to synthesize a near-zero stiffness zone, thereby improving the vibration isolation effect against slight low-frequency vibrations. When the descending distance of the first enclosure 51 is small, the ratio of the height to the thickness of the elastic body 8 increases within a certain range, which can provide a smaller negative stiffness, making the synthetic stiffness closer to zero stiffness, reducing the natural frequency of the vibration isolation system, making the range of the resonance zone smaller, and improving the vibration isolation effect.

[0027] The present invention solves the problems that the airbag is prone to produce air pressure fluctuations under loads with large dynamic fluctuations, resulting in a decrease in vibration isolation performance; the problem that the load adaptability to large dynamic fluctuations is poor and the vibration isolation bandwidth is limited, and has the following beneficial effects: complicating the gas flow channel inside the airbag cavity 5, improving the internal damping of the airbag cavity 5, increasing the range of the vibration suppression bandwidth that can be adapted, and improving the vibration isolation effect; the elastomer 8 between the airbag cavity 5 and the enclosure forms a positive stiffness and negative stiffness parallel mechanism to synthesize a near-zero stiffness zone, thereby improving the vibration isolation effect on micro-amplitude low-frequency vibrations and achieving high-precision vibration suppression; the signal of the trigger device 43 at the end of the stroke of the first electromagnetic actuator 4 is used to control whether the airbag cavity 5 performs air intake, exhaust and gas circulation rate signals through the servo valve 9, thereby achieving millisecond-level vibration suppression.

[0028] The above embodiments are only used to illustrate the preferred embodiments for implementing the technology of the present invention, and are not intended to limit the embodiments of the technology of the present invention in any form. Any person skilled in the art may make slight changes to other equivalent embodiments without departing from the scope of the technical means disclosed in the content of the present invention, but they should still be regarded as technologies or embodiments that are essentially the same as the present invention.

Claims

1. An active vibration isolation system with a servo valve, comprising a working platform (1) and a mounting platform (2) below the working platform (1), characterized in that: An airbag cavity (5) is provided between the mounting platform (2) and the working platform (1), the airbag cavity (5) connecting the working platform (1) and the mounting platform (2), a first electromagnetic actuator (4) is provided inside the airbag cavity (5), a trigger device (43) is provided at the end of the stroke of the first electromagnetic actuator (4), the airbag cavity (5) is provided with an air inlet (6) and an air outlet (7), and the trigger device (43) is connected to the air inlet (6) and the air outlet (7).

2. The active vibration isolation system with a servo valve according to claim 1, characterized in that: A second electromagnetic actuator (3) is provided outside the airbag cavity (5), and the second electromagnetic actuator (3) includes a fixed end (32) and a movable end (31). The movable end (31) of the second electromagnetic actuator (3) is connected to the bottom of the working platform (1), and the fixed end (32) of the second electromagnetic actuator (3) is connected to the mounting platform (2).

3. The active vibration isolation system with a servo valve according to claim 2, characterized in that: At least two second electromagnetic actuators (3) are provided outside the airbag cavity (5), and the second electromagnetic actuators (3) are evenly distributed around the circumference.

4. The active vibration isolation system with a servo valve according to claim 1, characterized in that: The first electromagnetic actuator (4) comprises a trigger end (41) and a detection end (42); the detection end (42) of the first electromagnetic actuator (4) is provided on the top surface of the mounting platform (2); the trigger end (41) of the first electromagnetic actuator (4) is provided on the bottom surface of the working platform (1); and a trigger device (43) is provided on the side of the detection end (42) of the first electromagnetic actuator (4) close to the trigger end (41).

5. The active vibration isolation system with a servo valve according to claim 4, characterized in that: The airbag cavity (5) comprises a first enclosure (51) and a second enclosure (52), both of which are annular. The length direction of the first enclosure (51) extends from the bottom surface of the working platform (1) to the mounting platform (2), and the height direction of the second enclosure (52) extends from the top surface of the mounting platform (2) to the working platform (1). The first enclosure (51) and the second enclosure (52) are staggered.

6. The active vibration isolation system with a servo valve according to claim 5, characterized in that: The height of the trigger device (43) matches the distance from the end of the first enclosure (51) to the installation platform (2).

7. The active vibration isolation system with a servo valve according to claim 5, characterized in that: The second enclosure (52) is located outside the first enclosure (51), and an elastic body (8) is provided on the outer wall of the outer ring of the first enclosure (51), and the elastic body (8) connects the first enclosure (51) and the second enclosure (52).

8. The active vibration isolation system with a servo valve according to claim 7, characterized in that: The elastic body (8) is conical, the small end of the cone is connected to the first enclosure (51), and the large end of the cone is connected to the second enclosure (52).

9. The active vibration isolation system with a servo valve according to claim 5, characterized in that: The outer wall of the second enclosure (52) is provided with a servo valve (9), and the outer wall of the second enclosure (52) is also provided with an exhaust hole (7) and an air inlet hole (6), and the trigger device (43) is connected to the exhaust hole (7) and the air inlet hole (6) through the servo valve (9).

10. The active vibration isolation system with a servo valve according to claim 4, characterized in that: The trigger device (43) is a platform, the large end of the platform is connected to the detection end (42) of the first electromagnetic actuator (4), and the small end of the platform is located at the end of the stroke of the trigger end (41) of the first electromagnetic actuator (4).

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