A quasi-zero stiffness semi-active vibration isolator with excitation and load adaptation

Abstract

The application discloses a kind of quasi-zero stiffness semi-active vibration isolator of excitation and load adaptation, it is related to vibration control technical field, it solves the problem that semi-active vibration isolation technology exists high energy consumption, large heat and control dependency.The base is provided with guide rod, and the both ends of negative stiffness bearing plate and a part of guide rod are slidably connected, and bearing plate and another part of guide rod are slidably connected;Spring is arranged on the guide rod connected with bearing plate;Negative stiffness bearing plate and bearing plate are connected by clutch structure;Negative stiffness bearing plate and base are connected by negative stiffness mechanism;Negative stiffness adjustment module is connected with negative stiffness bearing plate by clutch structure;Load is placed on bearing plate.The application uses quasi-zero stiffness structure itself to bear main vibration isolation effect, reduces the dependence on continuous energy consumption, simultaneously improves the adaptability of vibration isolation system to different excitation frequency, load state and operating condition by semi-active control, and gives consideration to low energy consumption, wide frequency adaptability and operating stability.

Description

Technical Field

[0001] This invention relates to the field of vibration control technology, specifically to a quasi-zero stiffness semi-active vibration isolator that adapts to excitation and load. Background Technology

[0002] In fields such as industrial production, scientific research, and precision manufacturing, many critical pieces of equipment are highly sensitive to vibration, and adverse vibrations can affect their working accuracy and operational stability. Therefore, efficient, reliable, and low-energy-consumption vibration isolation technology is an important means to ensure the stable operation of high-end equipment.

[0003] Quasi-zero stiffness isolators, through a combination of positive and negative stiffness mechanisms, can reduce the equivalent dynamic stiffness of the system while ensuring static load-bearing capacity, thereby achieving a low initial isolation frequency and good high-frequency isolation performance. Since their isolation effect primarily stems from the low dynamic stiffness characteristics of the structure itself, rather than continuous external energy input, they offer the advantage of low energy consumption. However, passive quasi-zero stiffness isolators have fixed structural parameters, making them prone to resonance amplification in the low-frequency region, exhibiting significant resonance peaks. This, in turn, exacerbates the vibration response of the isolated object, limiting their application in precision equipment and broadband vibration isolation scenarios. Furthermore, when the load mass changes, they often deviate from the designed operating range, leading to a deterioration in isolation performance.

[0004] To improve the adaptability of vibration isolation systems, semi-active vibration isolation technology has been developed. Most existing semi-active vibration isolators use variable damping or variable stiffness elements, combined with corresponding control strategies, to adjust the system's dynamic characteristics in real time to improve vibration isolation performance. However, most current semi-active vibration isolation technologies rely on continuous energy consumption to achieve vibration control, which leads to problems such as high energy consumption, large heat generation, and strong control dependence in long-term operation scenarios.

[0005] Therefore, it is necessary to combine the low energy consumption advantage of quasi-zero stiffness vibration isolation with the parameter adjustment advantage of semi-active vibration control to form a semi-active quasi-zero stiffness vibration isolation technology. Summary of the Invention

[0006] To address the problems of high energy consumption, high heat generation, and strong control dependence in existing semi-active vibration isolation technologies, this invention proposes a quasi-zero stiffness semi-active vibration isolator with excitation and load self-adaptation. This invention utilizes the quasi-zero stiffness structure itself to undertake the main vibration isolation function, reducing dependence on continuous energy consumption. Simultaneously, it improves the adaptability of the vibration isolation system to different excitation frequencies, load states, and operating conditions through semi-active control, thus achieving a balance of low energy consumption, wide bandwidth adaptability, and operational stability.

[0007] This invention proposes a quasi-zero stiffness semi-active vibration isolator with excitation and load self-adaptation, specifically comprising a base, a negative stiffness bearing plate, several guide rods, a bearing plate, a negative stiffness adjustment module, a negative stiffness mechanism, and two clutch mechanisms. Several guide rods are arranged on the base; the negative stiffness bearing plate is slidably connected to both ends and a portion of the guide rods, and the bearing plate is slidably connected to another portion of the guide rods; springs are arranged on the guide rods connected to the bearing plate; the negative stiffness bearing plate and the bearing plate are connected via clutch mechanisms; the negative stiffness bearing plate and the base are connected via the negative stiffness mechanism; the negative stiffness adjustment module is connected to the negative stiffness bearing plate via the clutch mechanisms; and a load is placed on the bearing plate.

[0008] Furthermore, the clutch structure includes a motor, a stiffness switching module, and a rack. The output shaft of the motor is connected to the stiffness switching module via a threaded rod, and the stiffness switching module is connected to the rack.

[0009] Furthermore, the stiffness switching module includes a rack connector, a flexible buffer, a connector, and a fixing member. The rack connector and the connector are slidably mounted on the fixing member. A flexible buffer is provided between the rack connector and the connector. The rack connector and the rack mesh. The connector and the threaded rod are threadedly connected. The rack passes through a through hole on the fixing member and meshes with the rack connector.

[0010] Furthermore, the stiffness switching module also includes several connecting rods; one end of the connecting rod is fixedly connected to the rack connector, and the other end is slidably connected to the connector.

[0011] Furthermore, the negative stiffness mechanism includes two symmetrically arranged negative stiffness modules, which are connected by two springs.

[0012] Furthermore, the negative stiffness module includes a fixed plate, two support arms, and two connecting arms; the two support arms are symmetrically arranged on the fixed plate; one end of the support arm is rotatably connected to the fixed plate, and the other end is rotatably connected to the connecting arm; one connecting arm is connected to the base, and the other connecting arm is connected to the negative stiffness bearing plate.

[0013] Furthermore, the fixed plate, support arm, and connecting arm are rotatably connected by bearings.

[0014] Furthermore, the negative stiffness adjustment module includes a lifting platform, a drive motor, a lead screw, and a lifting bracket. The lifting bracket is mounted on a base, and a drive motor is mounted on the upper end of the lifting bracket. The lifting platform is slidably mounted on the lifting bracket. The output shaft of the drive motor is connected to the lead screw, and the lead screw is threadedly connected to the lifting platform. A clutch structure is provided on the lifting platform.

[0015] Furthermore, the negative stiffness bearing plate and the bearing plate are provided with a plurality of linear bearings, and the linear bearings and the guide rod are slidably connected.

[0016] Furthermore, a support is provided at the lower end of the guide rod, and the support is connected to the base.

[0017] The beneficial effects of the excitation and load adaptive quasi-zero stiffness semi-active vibration isolator described in this invention are as follows: (1) The excitation and load adaptive quasi-zero stiffness semi-active vibration isolator described in this invention can adaptively switch between different stiffness modes according to the external excitation frequency to maintain good performance over a wide frequency range. It can determine whether the load has changed through the real-time response of the load, and adjust the equilibrium position of the system when the load changes, so that the vibration isolator can adapt to different loads. It combines the advantages of semi-active control and low power consumption, and is suitable for vibration control fields with requirements for wide frequency isolation and energy consumption and where the load may change. Attached Figure Description

[0018] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0019] In the attached diagram: Figure 1 This is a structural schematic diagram of a quasi-zero stiffness semi-active vibration isolator with excitation and load self-adaptation as described in this invention. Figure 2 This is a schematic diagram of the negative stiffness mechanism of a quasi-zero stiffness semi-active vibration isolator with excitation and load self-adaptation as described in this invention. Figure 3 This is a structural schematic diagram of the stiffness switching module of a quasi-zero stiffness semi-active vibration isolator with excitation and load self-adaptation as described in this invention. Figure 4 This is a schematic diagram of the restoring force-displacement curve of a semi-active vibration isolator with excitation and load self-adaptation as described in this invention in quasi-zero stiffness mode. Figure 5 This is a schematic diagram of the stiffness-displacement curve of a semi-active vibration isolator with excitation and load self-adaptation as described in this invention in quasi-zero stiffness mode. Figure 6 This is a flowchart of the excitation adaptive control strategy for a quasi-zero stiffness semi-active vibration isolator with excitation and load self-adaptation as described in this invention. Figure 7 This is a flowchart of the load adaptive control strategy for a quasi-zero stiffness semi-active vibration isolator with excitation and load self-adaptation as described in this invention. Wherein: 1-base, 2-support, 3-spring one, 4-negative stiffness bearing plate, 5-linear bearing, 6-guide rod, 7-load, 8-rack one, 9-stiffness switching module one, 10-bearing plate, 11-negative stiffness adjustment module, 12-motor two, 13-stiffness switching module two, 14-negative stiffness mechanism, 15-bearing, 16-support arm, 17-fixed plate, 18-spring two, 19-spring fixing module, 20-rack connector, 21-flexible buffer, 22-connector, 23-fixer, 24-connecting arm, 25-motor one, 26-rack two. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the present invention can be combined with each other. The described embodiments are merely some embodiments of the present invention, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0021] Specific implementation method one: See Figures 1-7 This embodiment is described in detail. The quasi-zero stiffness semi-active vibration isolator with excitation and load self-adaptation described in this embodiment specifically includes a base 1, a negative stiffness bearing plate 4, several guide rods 6, a bearing plate 10, a negative stiffness adjustment module 11, a negative stiffness mechanism 14, and two clutch mechanisms. Several guide rods 6 are provided on the base 1, and supports 2 are provided at the lower ends of the guide rods 6, with the supports 2 fixedly mounted on the base 1. Each guide rod 6 includes two guide rod 1s and two guide rod 2s, with the length of the guide rod 2s being greater than that of the guide rod 1s. A linear bearing 5 is provided at both ends of the negative stiffness bearing plate 4, and the linear bearing 5 is sleeved on the guide rod 1s. The negative stiffness bearing plate 4 is connected to the guide rod 1s via the linear bearings 5. Sliding connection; a linear bearing 5 is provided at both ends of the bearing plate 10, and the bearing plate 10 is slidably connected to the guide rod 2 through the linear bearing 5; the bearing plate 10 is set above the negative stiffness bearing plate 4; a spring base and a spring 3 are provided on the guide rod 2, the lower end of the spring 3 contacts the spring base, and the upper end contacts the linear bearing 5 of the bearing plate 10; the negative stiffness bearing plate 4 and the bearing plate 10 are connected by a clutch structure 1; the negative stiffness bearing plate 4 and the base 1 are connected by a negative stiffness mechanism 14; the negative stiffness adjustment module 11 is connected to the negative stiffness bearing plate 4 through the clutch structure 2; a load 7 is placed on the bearing plate 10.

[0022] The first clutch structure includes a motor 25, a stiffness switching module 9, and a rack 8. Motor 25 and stiffness switching module 9 are mounted on the negative stiffness bearing plate 4. The output shaft of motor 25 is connected to stiffness switching module 9 via a threaded rod. Stiffness switching module 9 is connected to rack 8, and the upper end of rack 8 is connected to bearing plate 10. The second clutch structure includes a motor 12, a stiffness switching module 13, and rack 26. Motor 12 and stiffness switching module 13 are mounted on the negative stiffness adjustment module 11. The output shaft of motor 12 is connected to stiffness switching module 13 via a threaded rod. Stiffness switching module 13 is connected to rack 26, and the upper end of rack 26 is connected to negative stiffness bearing plate 4.

[0023] The stiffness switching module 1 (9) and stiffness switching module 2 (13) have the same structure, both including a rack connector 20, a flexible buffer 21, a connector 22, a fixing member 23, and several connecting rods. The rack connector 20 and the connector 22 are slidably mounted on the fixing member 23. One end of the connecting rod is fixedly connected to the rack connector 20, and the other end is slidably connected to the connector 22. The rack connector 20 and the connector 22 can slide relative to the connecting rod, and the outer wall of the fixing member 23 is provided with corresponding grooves to constrain the rack connector. The displacement direction of the connecting member 20 and the connecting member 22; the rack passes through the through hole on the fixing member 23 and meshes with the rack connecting member 20; a flexible buffer 21 is provided between the rack connecting member 20 and the connecting member 22. The rack connecting member 20 meshes with the rack, and the connecting member 22 is threadedly connected to the threaded rod. The threaded rod is driven to rotate by a motor, so that the connecting member 22 drives the rack connecting member 20 to move relative to the fixing member 23 in the horizontal direction, realizing the purpose of meshing and disengaging the rack connecting member 20 and the rack. Since the rack may have tooth tip contact during the switching between meshing and disengaging with the rack connecting member 20, the flexible buffer 21 is provided so that when the tooth tips of the two are in contact, the rack connecting member 20 can slide and adjust to mesh with the rack 8.

[0024] The negative stiffness mechanism 14 includes two symmetrically arranged negative stiffness modules connected by two springs 18. Each negative stiffness module includes a fixed plate 17, two support arms 16, and two connecting arms 24. The two support arms 16 are symmetrically arranged on the fixed plate 17; one end of each support arm 16 is rotatably connected to the fixed plate 17, and the other end is rotatably connected to the connecting arm 24. One connecting arm 24 is connected to the base 1, and the other connecting arm 24 is connected to the negative stiffness bearing plate 4. A spring fixing module 19 is provided on the fixed plate 17, and the spring fixing module 19 is connected to the springs 18. The fixed plate 17 and the support arms 16 are rotatably connected by bearings 15, and the support arms 16 and the connecting arms 24 are rotatably connected by bearings 15.

[0025] The negative stiffness adjustment module 11 includes a lifting platform, a drive motor, a lead screw, and a lifting bracket. The lifting bracket is mounted on the base 1, and the drive motor is mounted on the upper end of the lifting bracket. The lifting platform is slidably mounted on the lifting bracket. The output shaft of the drive motor is connected to the lead screw, and the lead screw is threadedly connected to the lifting platform. A second clutch structure is provided on the lifting platform. The drive motor drives the lead screw to rotate, and the lead screw drives the lifting platform to perform lifting and lowering movements.

[0026] When rack connector 20 and rack 8 in stiffness switching module 19 mesh with each other, and rack connector 20 and rack 26 in stiffness switching module 23 disengage from each other, negative stiffness and positive stiffness are connected in parallel, forming quasi-zero stiffness, and its static characteristics are as follows: Figures 4-5 As shown. In stiffness switching module 19, rack connector 20 and rack 8 are disengaged, and the vibration isolator operates in linear stiffness mode. When rack connector 20 and rack 8 are engaged in stiffness switching module 19, and rack connector 20 and rack 26 are engaged in stiffness switching module 23, the vibration isolator operates in rigid mode, meaning the bearing plate 10 cannot move relative to the base 1, and the transmissivity is always 1. This achieves the switching between the three stiffness modes.

[0027] The stiffness mode adapts to the frequency of the external excitation, and its process is as follows: Figure 6 As shown. The switching frequency is based on the frequency corresponding to a transmissibility of 1 in quasi-zero stiffness mode. Below this frequency, rigid mode is used, where the transmissibility of the vibration isolator is equal to 1. When the external excitation frequency is above this frequency, quasi-zero stiffness mode is used. Displacement signals between the bearing plate 4 and the negative stiffness bearing plate 10 are detected in real time using sensors.

[0028] The process of load adaptive regulation is as follows Figure 7 As shown. When the system load changes, the process of readjusting the system's equilibrium position is as follows: A load response threshold is set in advance. When the response signal exceeds this threshold, it is determined that the load has changed. At this time, the system uses the motor controller to disengage rack 8 from stiffness switching module 9. The load is then subjected to linear stiffness. Since linear stiffness itself does not have a designed equilibrium position, it will vibrate around the new equilibrium position. Simultaneously, the negative stiffness adjustment module 11 and clutch structure 2 return the negative stiffness mechanism 14 to its initial position. When the load response is detected to have entered a new stable state and the negative stiffness mechanism 14 has returned to its initial position, the stiffness switching module 9 is re-engaged with rack 8, causing the system to re-enter the quasi-zero stiffness mode. At this point, after adjustment, the system's dynamic equilibrium position has returned to its designed position; thus, matching the changing load is achieved.

[0029] In summary, the quasi-zero stiffness semi-active vibration isolator with excitation and load self-adaptation described in this invention can adaptively switch between different stiffness modes according to the external excitation frequency, maintaining good performance over a wide frequency range. It can determine whether the load has changed through real-time load response, and adjust the system's equilibrium position when the load changes, allowing the isolator to adapt to different loads. It combines the advantages of semi-active control and low power consumption, making it suitable for vibration control applications requiring wide-frequency isolation and low energy consumption, as well as those where the load changes.

[0030] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the invention. They can also be reasonable combinations of the features described in the above embodiments. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A quasi-zero stiffness semi-active vibration isolator with excitation and load self-adaptation, characterized in that: The system includes a base (1), a negative stiffness bearing plate (4), several guide rods (6), a bearing plate (10), a negative stiffness adjustment module (11), a negative stiffness mechanism (14), and two clutch mechanisms. Several guide rods (6) are provided on the base (1). The two ends of the negative stiffness bearing plate (4) and a part of the guide rods (6) are slidably connected. The bearing plate (10) and another part of the guide rods (6) are slidably connected. A spring is provided on the guide rods (6) connected to the bearing plate (10). The negative stiffness bearing plate (4) and the bearing plate (10) are connected by a clutch structure. The negative stiffness bearing plate (4) and the base (1) are connected by the negative stiffness mechanism (14). The negative stiffness adjustment module (11) is connected to the negative stiffness bearing plate (4) through the clutch structure. A load (7) is placed on the bearing plate (10).

2. The quasi-zero stiffness semi-active vibration isolator with excitation and load self-adaptation according to claim 1, characterized in that: The clutch structure includes a motor, a stiffness switching module, and a rack. The output shaft of the motor is connected to the stiffness switching module via a threaded rod, and the stiffness switching module is connected to the rack.

3. The quasi-zero stiffness semi-active vibration isolator with excitation and load self-adaptation according to claim 2, characterized in that: The stiffness switching module includes a rack connector (20), a flexible buffer (21), a connector (22), and a fixing member (23). The rack connector (20) and the connector (22) are slidably disposed on the fixing member (23). A flexible buffer (21) is disposed between the rack connector (20) and the connector (22). The rack connector (20) meshes with the rack, and the connector (22) is threadedly connected to the threaded rod. The rack passes through the through hole on the fixing member (23) and meshes with the rack connector (20).

4. The quasi-zero stiffness semi-active vibration isolator with excitation and load self-adaptation according to claim 3, characterized in that: The stiffness switching module also includes several connecting rods; one end of the connecting rod is fixedly connected to the rack connector (20), and the other end is slidably connected to the connector (22).

5. The quasi-zero stiffness semi-active vibration isolator with excitation and load self-adaptation according to claim 1, characterized in that: The negative stiffness mechanism (14) includes two symmetrically arranged negative stiffness modules, which are connected by two springs.

6. The quasi-zero stiffness semi-active vibration isolator with excitation and load self-adaptation according to claim 5, characterized in that: The negative stiffness module includes a fixed plate (17), two support arms (16) and two connecting arms (24); the two support arms (16) are symmetrically arranged on the fixed plate (17); one end of the support arm (16) is rotatably connected to the fixed plate (17), and the other end is rotatably connected to the connecting arm (24); one connecting arm (24) is connected to the base (1), and the other connecting arm (24) is connected to the negative stiffness bearing plate (4).

7. The quasi-zero stiffness semi-active vibration isolator with excitation and load self-adaptation according to claim 6, characterized in that: The fixed plate (17), the support arm (16) and the connecting arm (24) are rotatably connected by a bearing (15).

8. The quasi-zero stiffness semi-active vibration isolator with excitation and load self-adaptation according to claim 1, characterized in that: The negative stiffness adjustment module (11) includes a lifting platform, a drive motor, a lead screw and a lifting bracket. The lifting bracket is set on the base (1). The upper end of the lifting bracket is equipped with a drive motor. The lifting platform is slidably set on the lifting bracket. The output shaft of the drive motor is connected to the lead screw. The lead screw and the lifting platform are threadedly connected. A clutch structure is set on the lifting platform.

9. The quasi-zero stiffness semi-active vibration isolator with excitation and load self-adaptation according to claim 1, characterized in that: Several linear bearings (5) are provided on the negative stiffness bearing plate (4) and the bearing plate (10), and the linear bearings (5) and the guide rod (6) are slidably connected.

10. The quasi-zero stiffness semi-active vibration isolator with excitation and load self-adaptation according to claim 1, characterized in that: The lower end of the guide rod (6) is provided with a support (2), which is connected to the base (1).

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