Magnetostriction vibration isolation device based on hydraulic amplification

Abstract

According to the magnetostriction vibration isolation device based on hydraulic amplification, the hydraulic amplification mechanism is adopted to amplify magnetostriction output displacement, meanwhile, vibration energy consumption can be conducted, and active and passive double vibration isolation performance is achieved. According to the device, a magnetostrictive material is used as an actuator, pre-compression is applied by compressing a disc spring, a bias magnetic field is provided by a permanent magnet, and a hydraulic amplification mechanism is driven by a driving magnetic field generated by a solenoid. Damping holes are distributed in a closed containing cavity of the hydraulic amplification mechanism, output of an actuator enables a large flexible diaphragm of the hydraulic amplification mechanism to deform and extrude hydraulic oil, the hydraulic oil can pass through the damping holes in a liquid containing cavity after being extruded, vibration energy is consumed, and meanwhile a small flexible diaphragm is made to deform to achieve the displacement amplification effect. Therefore, the device not only can amplify the magnetostrictive displacement and widen the active vibration isolation amplitude value, but also can consume the vibration energy through the damping holes to further improve the vibration isolation performance.

Description

Technical Field

[0001] The invention relates to utilizing hydraulic amplification to amplify the displacement of a magnetostrictive actuator and then applying the amplification to the field of vibration isolation. Background Art

[0002] The magnetostrictive actuated vibration isolation device refers to a device that uses magnetostrictive material actuators to deform under a magnetic field, actively isolates vibrations by controlling the magnetic field output displacement, and reduces the interference of external vibrations on the load. The hydraulic displacement amplifier uses the hydraulic principle to drive the large piston in the closed cavity to squeeze the hydraulic oil, thereby driving the small piston to move, amplifying the output displacement, and setting a damping hole in the cavity to consume vibration energy to play a passive vibration isolation role. In this way, the vibration energy can be consumed through passive vibration isolation, and the active vibration isolation output displacement can be enhanced through the amplifier. At present, vibration isolation devices generally have small load output displacement, limited vibration isolation amplitude, and poor attenuation performance of vibration energy. Therefore, the development of a high-precision, strong load capacity, and both passive and active vibration isolation device is the key to achieving vibration isolation in large load, large displacement, and high frequency bandwidth. This will greatly improve the stability and reliability of optical instruments and further improve the static stability of the working environment. Summary of the invention

[0003] In view of the above problems, the purpose of the present invention is to provide a magnetostrictive vibration isolation device based on hydraulic amplification. The device is based on an actuator made of a magnetostrictive rod. The magnetostrictive rod with pre-pressure is placed in a composite magnetic field composed of a permanent magnet and a solenoid. The size of the magnetic field is changed by controlling the current of the solenoid, so that the magnetostrictive rod obtains different elongations to follow the vibration amplitude, realizing the active vibration isolation function. The output end of the magnetostrictive actuator is connected to the input end of the hydraulic displacement amplifier through a push rod to realize the displacement amplification function and broaden the active vibration isolation amplitude. This not only overcomes the shortcomings of the current micro-vibration isolator, such as the small vibration isolation amplitude range and weak load capacity, but also adds a damping device to the hydraulic amplification mechanism, further attenuating the vibration amplitude through passive vibration isolation, further broadening the applicable working conditions of the device, and greatly improving the vibration isolation and displacement amplification performance and expanding its application field. Due to the characteristics of the magnetostrictive material itself, its output displacement is sensitive to the pre-pressure. Adjusting the pre-pressure to a suitable range can also greatly enhance its displacement output capacity. At the same time, magnetostrictive materials have the frequency doubling characteristics and can only expand but not contract. They are also sensitive to the uniformity of the magnetic field and need to enhance the bias magnetic field to improve their bidirectional output capability.

[0004] To achieve the above purpose, the present invention is a magnetostrictive vibration isolation device based on hydraulic amplification. The device includes: a bottom plate, a lower permanent magnet, a yoke, a housing, a solenoid, a magnetostrictive rod, a connecting rod, an upper permanent magnet, a force sensor, a disc spring, a pre-tightening nut, a push rod, a hydraulic amplifier, an end cover, a linear bearing, an output rod, and a load. The vibration isolation device is based on a magnetostrictive actuator as a driving component. The pre-tightening nut and the disc spring provide pre-pressure for the magnetostrictive rod, and an initial elongation is generated under the bias magnetic field provided by the permanent magnet. By adjusting the current of the solenoid to control the driving magnetic field, the magnetostrictive rod can achieve bidirectional displacement output, and the vibration displacement is followed and isolated, thereby realizing the vibration isolation function. The input end of the hydraulic displacement amplifier, i.e., the large flexible diaphragm end, is connected to the output end of the actuator through a push rod. Under the action of the magnetic field, the output of the actuator causes the large flexible diaphragm to deform and squeeze the hydraulic oil in the closed cavity of the amplifier, thereby squeezing the small flexible diaphragm to deform, achieving displacement amplification and increasing the output displacement amplitude. At the same time, the hydraulic oil flows through the damping hole in the closed cavity, consuming vibration energy to further reduce the vibration amplitude, thereby achieving a two-way enhancement effect of active and passive vibration isolation. The small flexible diaphragm is connected to the load through the output rod to reduce the interference of external vibration on the load. In order to enhance the load-bearing and anti-interference capabilities of the output rod, a linear bearing is also used for guidance.

[0005] The working process of a magnetostrictive vibration isolation device based on hydraulic amplification is as follows: the pre-tightening nut is adjusted to compress the disc spring to apply pressure to the magnetostrictive rod, and the appropriate pre-pressure is monitored and controlled by the force sensor to improve the telescopic performance of the magnetostrictive rod; the magnetostrictive rod generates an initial elongation under the bias magnetic field of the permanent magnet, and the electromagnetic field generated by the solenoid after power-on forms a composite magnetic field with the bias magnetic field of the permanent magnet and serves as the driving magnetic field of the actuator, realizing the bidirectional displacement output of the magnetostrictive rod. When the intensity of the driving magnetic field is zero, the actuator outputs the lower limit, and when the intensity of the driving magnetic field is the maximum, the actuator outputs the upper limit. The large flexible diaphragm of the hydraulic displacement amplifier is connected to the output end of the magnetostrictive actuator, and the liquid chamber is a closed chamber, which is distributed with damping holes and filled with incompressible viscous hydraulic oil. When the actuator is working, the output of the push rod causes the large flexible diaphragm to deform and squeeze the hydraulic oil in the cavity. After being squeezed, the hydraulic oil will pass through the damping hole in the cavity and exert pressure on the small flexible diaphragm, causing the small flexible diaphragm to deform and output a larger displacement to achieve the effect of displacement amplification. The displacement amplification factor is the ratio of the area of ​​the large flexible diaphragm to the area of ​​the small flexible diaphragm, and the reciprocating flow of the hydraulic oil in the damping hole further consumes the vibration energy and enhances the passive vibration isolation capability. The output rod is connected to the small flexible diaphragm of the amplifier, and the small flexible diaphragm is connected to the load through the output rod to isolate the load from vibration.

[0006] Preferably, the actuator uses a round rod-shaped workpiece made of magnetostrictive material, which has a higher energy density, lower energy consumption and greater load capacity;

[0007] Preferably, two permanent magnets, one above the other, are used to provide a bias magnetic field, which can provide a uniform and stable magnetic field environment;

[0008] Preferably, the shell of the solenoid is made of a highly thermally conductive magnetic isolation material, and heat dissipation fins are evenly distributed on the surface, which can reduce magnetic leakage and increase the heat dissipation capacity of the solenoid during operation;

[0009] Preferably, a disc spring is used to apply pre-pressure to the magnetostrictive rod, which has the advantages of high rigidity and strong buffering and vibration absorption ability, can withstand large loads with small deformation, and can reduce the volume of the device;

[0010] Preferably, the hydraulic amplifier uses a flexible diaphragm as input and output ends to enhance deformation and displacement output capabilities;

[0011] Preferably, the hydraulic chamber is distributed with damping holes and is filled with incompressible viscous fluid, which can increase damping and consume vibration energy while amplifying displacement, thereby enhancing vibration isolation capability;

[0012] Preferably, the output rod is guided by a linear bearing to improve the load-bearing capacity and anti-interference characteristics.

[0013] The present invention is a magnetostrictive vibration isolation device based on hydraulic amplification. The device is based on a magnetostrictive actuator and a hydraulic amplifier. A compression disc spring applies pre-pressure to a magnetostrictive rod. A pair of permanent magnets are used to provide a bias magnetic field of the actuator to improve the bidirectional displacement output capacity. The electromagnetic field generated by the solenoid drives the magnetostrictive rod to expand and contract. The output end of the actuator is connected to a large flexible diaphragm as the input of the hydraulic displacement amplifier. Damping holes are distributed in the liquid cavity. The deformation of the large flexible diaphragm will squeeze the hydraulic oil. After being squeezed, the hydraulic oil will pass through the damping holes in the cavity, consuming the vibration energy while applying pressure to the small flexible diaphragm to cause the small flexible diaphragm to deform and amplify the displacement. The magnetostrictive actuator and the hydraulic amplifier work together to perform active and passive vibration isolation on the load. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention is described below in conjunction with the accompanying drawings.

[0015] Figure 1 is a schematic structural diagram of a magnetostrictive vibration isolation device based on hydraulic amplification according to one embodiment of the present invention;

[0016] Figure 2 is a schematic structural diagram of a hydraulic amplifier according to an embodiment of the present invention;

[0017] Figure 3 is a schematic diagram of a flexible membrane structure according to an embodiment of the present invention; DETAILED DESCRIPTION

[0018] The specific implementation of the present invention will be described in detail below in conjunction with the accompanying drawings. It should be understood that the implementation described below is only exemplary and not restrictive.

[0019] like Figure 1 As shown, a magnetostrictive vibration isolation device based on hydraulic amplification includes: a base plate 1, a lower permanent magnet 2, a yoke 3, a shell 4, a solenoid 5, a magnetostrictive rod 6, a connecting rod 7, an upper permanent magnet 8, a force sensor 9, an end cover 10, a disc spring 11, a pre-tightening nut 12, a push rod 13, a hydraulic amplifier 14, a bearing seat 15, a linear bearing 16, an output rod 17, and a load 18. The center of the shell 4 has a cylindrical installation space and is fixed to the base plate 1 with bolts. The lower permanent magnet 2 is placed at the bottom center of the shell 4 and is pressed by the yoke 3. The wire of the solenoid 5 is evenly wound around the outside of the yoke 3 through the opening of the shell 4. The magnetostrictive rod 6 is located at the center of the yoke 3 and is connected to the internal thread end of the force sensor 9 through the connecting rod 7 above. The upper permanent magnet 8 passes through the connecting rod 7 through the circular hole in the center and is installed above the yoke 3 to form a bias magnetic field with the lower permanent magnet 2, thereby improving Uniformity of magnetic field and bidirectional output displacement capacity of magnetostrictive rod; the external thread end of force sensor 9 is connected with push rod 13 as a whole, end cover 10 is fixed to housing 4 by bolts and presses permanent magnet 8, and the inner part of end cover 10 is tapped with thread, disc spring 11 and pre-tightening nut 12 are sleeved on push rod 13, the external thread of pre-tightening nut 12 is matched with the internal thread of end cover 10, and the disc spring 11 is compressed by the rotation of pre-tightening nut 12 to apply pre-pressure to magnetostrictive rod 6, so as to improve the displacement output capacity of magnetostrictive rod 6; hydraulic amplifier 14 is fixed on end cover 10, and push rod 13 is connected with the input end of hydraulic amplifier 14, linear bearing 16 is installed on bearing seat 15 and fixed with hydraulic amplifier 14, output rod 17 is connected with the output end of hydraulic amplifier 14 through the guide of linear bearing 16, and load 18 is installed in load output rod 17.

[0020] like Figure 2As shown, it is a schematic diagram of the structure of the hydraulic amplifier 14, including: a liquid chamber 19, a large flexible diaphragm 20, an amplifier housing 21, a small sealing ring 22, a small flexible diaphragm 23, a damping hole 24, and a large sealing ring 25. The middle of the amplifier housing 21 is processed into a large chamber and a small chamber. The large chamber is truncated and the small chamber is cylindrical. The two are connected as a whole through the damping hole 24 to form a closed liquid chamber 19. The large flexible diaphragm 20 is fixed to the large chamber side by bolts and sealed with a large sealing ring 25. The small flexible diaphragm 23 is fixed to the small chamber. The cavity side is sealed with a small sealing ring 22, and the deformation of the large flexible diaphragm 20 squeezes the liquid in the liquid chamber 19. The liquid flows through the damping hole 24 and squeezes the small flexible diaphragm 23. Since the hydraulic oil is incompressible, the deformation volume of the large flexible diaphragm 20 is the same as the deformation volume of the small flexible diaphragm 23, and the large flexible diaphragm 20 has a larger area. Therefore, the output displacement amplification factor of the small flexible diaphragm 23 is the ratio of the area of ​​the large flexible diaphragm 20 to the area of ​​the small flexible diaphragm 23, which plays a role in displacement amplification. At the same time, the hydraulic oil shuttles back and forth in the damping hole 24, which consumes vibration energy.

[0021] like Figure 3 As shown, a schematic diagram of the structure of a large flexible diaphragm 20 includes: a hard core 26, a thin film 27, and a rounded feature 28. The flexible diaphragm is circular in shape, and circular grooves are symmetrically opened on both sides to form the thin film 27. A thicker hard core 26 is formed in the middle of the diaphragm, and a rounded feature 28 is processed at the bottom of the groove. Since the axial stiffness of the hard core 26 is much greater than the axial stiffness of the thin film 27, when one side of the flexible diaphragm is subjected to pressure, the hard core 26 basically does not deform, and the deformation mainly occurs at the thin film 27. The rounded feature 28 can avoid stress concentration when deformation occurs.

[0022] Based on this disclosure, many variations in the configuration and operational sequence of the illustrated and described features will be apparent to those skilled in the art. Therefore, it should be appreciated that various changes can be made to this patent without departing from the spirit and scope of the claimed subject matter.

Claims

1. A magnetostrictive vibration isolation device based on hydraulic amplification, characterized in that include: A base plate (1), a lower permanent magnet (2), a yoke (3), a housing (4), a solenoid (5), a magnetostrictive rod (6), a connecting rod (7), an upper permanent magnet (8), a force sensor (9), an end cover (10), a disc spring (11), a pre-tightening nut (12), a push rod (13), a hydraulic amplifier (14), a bearing seat (15), a linear bearing (16), an output rod (17), and a load (18); the housing (4) is fixed on the base plate (1), the lower permanent magnet (2) is installed at the bottom of the housing (4) and is pressed by the yoke (3), the solenoid (5) is evenly wound on the outside of the yoke (3), the magnetostrictive rod (6) is located at the center of the yoke (3) and is connected to the force sensor (9) by a connecting rod (7); the upper permanent magnet (8) is pressed on the upper part of the yoke (3) to form a deflection with the lower permanent magnet (2). The magnetostrictive rod (6) is provided with a magnetic field to improve the uniformity of the magnetic field and the bidirectional output displacement capability of the magnetostrictive rod (6); the force sensor (9) is integrally connected with the push rod (13); the end cover (10) is fixed to the housing (4) by bolts and presses the upper permanent magnet (8); the disc spring (11) and the pre-tightening nut (12) are pressed on the push rod (13) to apply pre-pressure to the magnetostrictive rod (6) to improve the displacement output capability of the magnetostrictive rod (6); the hydraulic amplifier (14) is installed on the end cover (10) by bolts and the input end is connected to the push rod (13); the linear bearing (16) is installed on the bearing seat (15) and fixed to the hydraulic amplifier (14) by screws; the output rod (17) is connected to the output end of the hydraulic amplifier (14) through the guide of the linear bearing (16); and the load (18) is installed in the load output rod (17); A hydraulic amplifier (14) is characterized by comprising: a liquid chamber (19), a large flexible diaphragm (20), an amplifier housing (21), a small sealing ring (22), a small flexible diaphragm (23), a damping hole (24), and a large sealing ring (25). The middle of the amplifier housing (21) is a truncated cone-shaped large chamber and a cylindrical small chamber, which are connected as a whole through a damping hole (24) to form a closed liquid chamber (19). The large flexible diaphragm (20) is sealed with a large sealing ring (25) and fixed to one side of the amplifier housing (21) with bolts. The small flexible diaphragm (23) is sealed with a small sealing ring (22) and fixed to the other side of the amplifier housing (21) with bolts. The deformation of the large flexible diaphragm (20) squeezes the liquid in the liquid chamber (19). The liquid deforms the small flexible diaphragm (23) through the damping hole (24), thereby improving the vibration isolation capability and displacement amplification. The features of the flexible diaphragm include: a hard core (26), a thin film (27), and a rounded corner feature (28). The outer contour of the flexible diaphragm is circular, and circular grooves are symmetrically opened on the upper and lower surfaces to form the thin film (27). A thicker hard core (26) is formed in the middle of the diaphragm. The axial stiffness of the hard core (26) is much greater than the axial stiffness of the thin film (27). The edge of the thin film (27) is designed as a rounded corner feature (28) to avoid stress concentration when deformation occurs.

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