Self-sensing magnetic liquid damping shock absorber and preparation method thereof

Abstract

The present application relates to a self-sensing magnetic liquid damping vibration absorber and a preparation method thereof. The self-sensing magnetic liquid damping vibration absorber is used to be installed on the structure to be damped. The self-sensing magnetic liquid damping vibration absorber includes: a shell, an insulating tube, two high charge density parts, two conductive parts, a permanent magnet, and an ammeter. The self-sensing magnetic liquid damping vibration absorber combines power generation indication with vibration reduction based on dynamic double electric layer power generation technology and the second-order buoyancy principle of magnetic liquid, thereby realizing vibration monitoring and vibration reduction at the same time, and is not affected by other environmental factors. It only indicates and reduces vibration, achieving the effect of stable vibration monitoring and vibration reduction.

Description

Technical Field

[0001] The present application relates to the field of vibration control technology, and in particular to a self-sensing magnetic liquid damping vibration isolator and a preparation method thereof. Background Art

[0002] Devices or structures such as precision instrument bases, high-precision railroad bases, spacecraft solar panels, machine tool processing tables, and bridge foundations often experience vibration during operation due to dynamic or passive dynamic processes. Excessive vibration frequency, amplitude, and duration can cause these devices or structures to malfunction, lose precision, or even fail, creating safety hazards.

[0003] In existing technology, vibration sensors are typically installed throughout a structure to monitor vibration, and damping devices are installed to reduce vibration. Vibration sensors are categorized into displacement sensors, acceleration sensors, and velocity sensors. Specifically, displacement sensors include laser vibrometers, fiber optic displacement and strain sensors, and capacitive sensors; acceleration sensors include microcapacitors, microstrain sensors, and electrostatic balance sensors; and velocity sensors include magnetoelectric, Hall effect, and photoelectric effect sensors.

[0004] However, existing vibration dampers lack self-sensing capabilities, necessitating the simultaneous installation of sensors and dampers for monitoring and vibration reduction, respectively, to achieve the desired vibration reduction. These sensors are typically complex, costly, have poor anti-interference capabilities, are limited in functionality, and exhibit poor durability. These miniature sensors must be secured to the target location of the structure under test using adhesives and other methods, resulting in poor durability and the risk of detachment. Summary of the Invention

[0005] Based on this, it is necessary to install the above-mentioned sensors and vibration reduction sensors at the same time to monitor and reduce vibration respectively, in order to ultimately achieve the purpose of vibration reduction, as the existing shock absorbers do not have self-sensing capabilities and there is no precedent for fixed use with tuned liquid dampers. However, the existing vibration sensors are usually complex in structure, high in cost, poor in anti-interference ability, single in function and poor in durability. The miniature sensors need to be fixed to the target part of the structure to be measured by gluing or other methods, so they have poor durability and are very easy to fall off. Based on dynamic double-layer power generation technology and the second-order buoyancy principle of magnetic liquid, a self-sensing magnetic liquid damping shock absorber and a preparation method thereof are provided.

[0006] The self-sensing magnetic liquid damping vibration absorber of the present invention is different from traditional sensors based on electromagnetic, optical, piezoelectric, etc. The self-sensing magnetic liquid damping vibration absorber of the present invention is based on the shielding effect of the double electric layer at the solid-liquid interface on the surface charge. Compared with the core sensitive elements of traditional sensors, it has the advantage of high output (the output of the core sensitive elements of traditional sensors is often only a few millivolts, so a signal amplification circuit is required for signal amplification, while the output of the ammeter of the present invention is in the volt level). Compared with the sensitive elements of traditional sensors, the present invention has improved by 2-3 orders of magnitude.

[0007] A self-sensing magnetic liquid damping vibration isolator is used to be installed on a structure to be damped. The self-sensing magnetic liquid damping vibration isolator comprises: a shell, an insulating tube, two high charge density parts, two conductive parts, a permanent magnet, and an ammeter;

[0008] The shell contains a magnetic liquid, and the permanent magnet is immersed in the magnetic liquid; one end of the shell along the first direction is connected to the structure to be damped, and the other end of the shell along the first direction is connected to the outer wall of the insulating tube;

[0009] The two magnetic poles of the permanent magnet are arranged along a first direction;

[0010] One of the high charge density components is respectively provided at both ends of the insulating tube along the second direction, and the side wall of the insulating tube and the two high charge density components form an insulating cavity; the insulating cavity partially contains a conductive liquid, and the two high charge density components are respectively connected to one of the conductive components on the sides facing away from each other along the second direction; the two conductive components are respectively electrically connected to the positive and negative poles of the ammeter; the second direction is set at an angle to the first direction, and the second direction is the tube length direction of the insulating tube.

[0011] In actual use, the self-sensing magnetic liquid damping vibration isolator described above is connected to the structure to be damped at one end along a first direction, and connected to the outer wall of an insulating tube at the other end along the first direction. The insulating tube is positioned along a second direction. When the structure to be damped is stable, the contact area between the conductive liquid and the high-charge density components on either side of the second direction remains unchanged. The direction and magnitude of the current in the circuit formed by the conductive liquid, the high-charge density components, the conductive components, and the ammeter remain unchanged, thereby causing the ammeter's indication signal to remain unchanged. The permanent magnet is positioned at the center of the magnetic liquid. At this time, the ammeter's signal indicates no vibration, and the permanent magnet is not damping vibration. When the structure to be damped vibrates, the contact area between the conductive liquid and the high-charge density components on either side of the second direction changes periodically. The charge density changes caused by the change in contact area cause the ammeter's reading or light to increase (brighten) or decrease (dim), thereby indicating the vibration amplitude. When the permanent magnet is offset to either side along the second direction due to vibration, the magnetic liquid will generate a magnetic force on the permanent magnet to make the permanent magnet return to the center position of the magnetic liquid body, so that the permanent magnet produces a vibration reduction effect in the second direction during the process of returning to the stable position. At the same time, the conductive liquid will return to a stable state without vibration due to gravity during the vibration process, thereby also producing a smaller vibration reduction effect when returning to the stable state. The above-mentioned self-sensing magnetic liquid damping shock absorber combines power generation indication with vibration reduction based on dynamic double-layer power generation technology and the second-order buoyancy principle of magnetic liquid, thereby realizing vibration monitoring and vibration reduction at the same time, and is not affected by other environmental factors. It only indicates and reduces vibration, achieving the effect of stable vibration monitoring and vibration reduction. In one embodiment, the end faces of the two poles of the permanent magnet, the end face of the shell connected to the structure to be damped, and the axis of the insulating tube are parallel.

[0012] In one embodiment, the self-sensing magnetic liquid damping vibration isolator further includes an insulating sheet, one side of the insulating sheet is connected to the high charge density component, and the other side of the insulating sheet is connected to the conductive component.

[0013] In one embodiment, the self-sensing magnetic liquid damping vibration isolator further includes a fixing member, one end of which is connected to an end of the shell away from the structure to be damped, and the other end of which is connected to the outer wall of the insulating tube.

[0014] In one embodiment, the housing includes an end cap and a base;

[0015] The base is provided with a receiving groove, and the magnetic liquid and the permanent magnet are located in the receiving groove;

[0016] The bottom end of the base is connected to the structure to be attenuated, the end cover covers the opening of the accommodating groove and is detachably connected to the base, and the side of the end cover away from the base is connected to the outer wall of the insulating tube.

[0017] In one embodiment, the shell further includes a fastener, the end cover is provided with a first through hole, the base is provided with a second through hole, and the fastener is passed through the first through hole and the second through hole to fasten the end cover to the base.

[0018] In one embodiment, the housing further includes a sealing ring, which is located between the end cover and the base and is used to seal a gap between the end cover and the base.

[0019] In one embodiment, the end cover includes a main body and a positioning portion, the main body cover is arranged at an end of the base away from the structure to be attenuated, the positioning portion is arranged at an end of the main body close to the structure to be attenuated and extends into the receiving groove, and the positioning portion is adapted to the opening of the receiving groove.

[0020] In one embodiment, a side of the positioning portion close to the structure to be vibrated is provided with an inclined groove, and an opening of the inclined groove faces the structure to be vibrated;

[0021] The groove wall of the inclined groove includes a first groove wall and a second groove wall that are inclined to each other, and the first groove wall is arranged on one side of the second groove wall along the second direction.

[0022] An embodiment of the present application further provides a method for preparing a self-sensing magnetic liquid damping vibration absorber, which is used to prepare the self-sensing magnetic liquid damping vibration absorber. The method for preparing the self-sensing magnetic liquid damping vibration absorber comprises the following steps:

[0023] 3D printing the shell and the insulating tube and connecting them;

[0024] cutting and cleaning the conductive member;

[0025] forming the high charge density member on the surface of the conductive member;

[0026] cleaning the surface of the conductive member again;

[0027] connecting the two electrodes of the ammeter to the two conductive members respectively to form an external circuit;

[0028] Connecting the two ends of the insulating tube to the conductive member containing the high charge density member respectively, and simultaneously adding the conductive liquid into the insulating cavity;

[0029] The magnetic liquid and the permanent magnet are placed in the shell.

[0030] Preparation method of self-sensing magnetic liquid damping vibration absorber The above-mentioned self-sensing magnetic liquid damping vibration absorber combines 3D printing technology to prepare the shell and insulating tube, manually prepares the bottom mortgage and high charge density parts, then adds conductive liquid to the insulating cavity, connects the ammeter and the conductive liquid, and adds magnetic liquid and permanent magnet to the shell, so that through simple operation and preparation, a self-sensing magnetic liquid damping vibration absorber that can simultaneously perform vibration monitoring and vibration reduction can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 Schematic cross-sectional view of a self-sensing magnetic liquid damping vibration absorber in one embodiment.

[0032] Figure 2 The figure is a vibration attenuation curve diagram of the structure to be damped measured by the laser displacement sensor after the present invention is installed.

[0033] Figure 3 The vibration attenuation process of the present invention is installed on the structure to be damped. Figure 1 The voltage signal is obtained by measuring the output electrical signal of the ammeter.

[0034] Figure 4 This is a graph showing the relationship between the volume of different conductive liquids, the mass of different magnetic liquids and the vibration decay time.

[0035] 100-Self-sensing magnetic liquid damping shock absorber;

[0036] 110 - housing; 111 - fastener; 112 - end cap; 1121 - body; 1122 - positioning portion; 1123 - inclined groove; 1124 - first groove wall; 1125 - second groove wall; 113 - base; 114 - receiving groove; 115 - fastener; 116 - first through hole; 117 - second through hole; 118 - sealing ring;

[0037] 120-insulating tube; 121-insulating cavity;

[0038] 130-high charge density piece;

[0039] 140-conductive parts;

[0040] 150-Permanent magnet;

[0041] 160-galvanometer; 161-wire;

[0042] 170-magnetic liquid;

[0043] 180-conductive liquid;

[0044] 190-insulation sheet;

[0045] R-actual vibration signal; V-voltage signal obtained from the electrical signal output by the meter; Q-signal attenuation trend line; OX-first direction; YY'-second direction; OY-positive direction of the second direction; OY'-positive direction of the second direction. DETAILED DESCRIPTION

[0046] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0047] In the description of this application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0048] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of this application, if the term "plurality" appears, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0049] In this application, unless otherwise specified or limited, the terms "mounted," "connected," "connected," "fixed," etc., should be interpreted broadly. For example, these terms may refer to fixed connections, removable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediary; and internal communication between two components or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0050] In this application, unless otherwise expressly specified or limited, if a first feature is described as being "above" or "below" a second feature, or similar descriptions, this may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is described as being "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is described as being "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0051] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only embodiment.

[0052] See Figure 1 , Figure 1 A cross-sectional schematic diagram of a self-sensing magnetic liquid damping vibration absorber 100 in an embodiment of the present application is shown. The self-sensing magnetic liquid damping vibration absorber 100 provided in an embodiment of the present application is used to be installed on a structure to be damped (not shown in the figure). The self-sensing magnetic liquid damping vibration absorber 100 includes: a shell 110, an insulating tube 120, two high charge density parts 130, two conductive parts 140, a permanent magnet 150, and an ammeter 160.

[0053] In the self-sensing magnetic liquid damping vibration isolator 100 described above, a magnetic liquid 170 is contained in the shell 110, and a permanent magnet 150 is immersed in the magnetic liquid 170. One end of the shell 110 along the first direction OX is connected to the structure to be damped, and the other end of the shell 110 along the first direction OX is connected to the outer wall of the insulating tube 120. The two magnetic poles of the permanent magnet 150 are arranged along the first direction OX, so that when the structure to be damped is stable, the permanent magnet 150 is located at the center of the magnetic liquid 170 with a regular volume. When the permanent magnet 150 deviates to either side of the second direction YY' due to vibration, the magnetic liquid 170 will generate a magnetic force on the permanent magnet 150 that causes the permanent magnet 150 to return to the center position of the magnetic liquid 170, so that the permanent magnet 150 produces a vibration damping effect in the second direction YY' during the process of returning to the stable position. A high charge density member 130 is provided at each end of the insulating tube 120 along the second direction YY'. The side wall of the insulating tube 120 and the two high charge density members 130 form an insulating cavity 121. The insulating cavity 121 partially contains a conductive liquid 180. The two high charge density members 130 are connected to a conductive member 140 on the side facing away from each other along the second direction YY'. The two conductive members 140 are electrically connected to the positive and negative poles of the ammeter 160, respectively. Therefore, when the vibration reduction structure to be stabilized is stable, the contact area between the conductive liquid 180 and the high charge density members 130 on both sides of the second direction YY' remains unchanged, thereby making the charge amount and the charge density per unit area on the high charge density member 130 unchanged. The direction and magnitude of the current in the circuit composed of the conductive liquid 180, the high charge density member 130, the conductive member 140 and the ammeter 160 remain unchanged, thereby making the indication signal of the ammeter 160 unchanged. Only the quotation marks can be transmitted and indicated by a reading or an audible or visual signal. When vibration occurs, the contact area between the conductive liquid 180 and the high charge density elements 130 on both sides of the second direction YY' changes periodically. The resulting charge density changes based on the contact area cause the reading or light of the ammeter 160 to increase (brighten) or decrease (dim), thereby indicating the vibration amplitude. The second direction YY' is angled with the first direction OX and is the longitudinal direction of the insulating tube 120.

[0054] In actual use of the self-sensing magnetic liquid damping vibration isolator 100, one end of the housing 110 along the first direction OX is connected to the structure to be damped, and the other end of the housing 110 along the first direction OX is connected to the outer wall of the insulating tube 120. The insulating tube 120 is placed along the second direction YY'. When the structure to be damped is stable, the contact area between the conductive liquid 180 and the high charge density members 130 on both sides of the second direction YY' remains unchanged. The direction and magnitude of the current in the circuit composed of the conductive liquid 180, the high charge density member 130, the conductive member 140, and the ammeter 160 remain unchanged, so that the indication signal of the ammeter 160 remains unchanged. The permanent magnet 150 is located at the center of the magnetic liquid 170. At this time, the signal of the ammeter 160 indicates no vibration, and the permanent magnet 150 does not perform vibration reduction. When the structure to be dampened vibrates, the contact area between the conductive liquid 180 and the high charge density members 130 on either side of the second direction YY' will periodically change. The resulting charge density changes based on these changes in contact area cause the reading or light of the ammeter 160 to increase (brighten) or decrease (dim), thereby indicating the vibration amplitude. When the permanent magnet 150 deviates toward either side along the second direction YY' due to vibration, the magnetic liquid 170 exerts a magnetic force on the permanent magnet 150, causing it to return to its center of mass. This results in a vibration-damping effect in the second direction YY' as the permanent magnet 150 returns to its stable position. Furthermore, during the vibration process, the conductive liquid 180 returns to a stable, non-vibrating state due to gravity, resulting in a smaller vibration-damping effect when returning to its stable state. The above-mentioned self-sensing magnetic liquid damping shock absorber 100 combines power generation indication with vibration reduction based on dynamic double-layer power generation technology and the second-order buoyancy principle of magnetic liquid, thereby realizing vibration monitoring and vibration reduction at the same time, and is not affected by other environmental factors. It only indicates and reduces vibration, achieving the effect of stable vibration monitoring and vibration reduction.

[0055] Specifically, Figure 2 This is a vibration attenuation curve of the structure to be damped measured by the laser displacement sensor after the present invention is installed. That is, this signal is the actual vibration signal R of the structure to be damped. Figure 3 The voltage signal V is obtained from the electrical signal output by the ammeter 160 of the present invention. As can be seen from the comparison of the signal attenuation trend line Q in the figure, Figure 3 The variation trend of the output voltage signal V of the ammeter 160 is Figure 2 The actual vibration attenuation trend of the test bench is consistent and linear, indicating that the self-sensing magnetic liquid damping vibration isolator 100 of the present invention can detect the vibration condition of the structure to be damped without the need for additional signal amplification and processing circuits, and has a self-sensing function.

[0056] The magnetic liquid 170, also known as magnetic fluid, is a uniform and stable colloidal solution formed by wrapping nanometer-scale (about 10 nanometers) magnetic particles with a layer of long-chain surfactant and uniformly dispersing them in a base liquid.

[0057] Specifically, the ammeter 160 may also be other electrical signal measuring instruments, such as a multimeter.

[0058] See Figure 1 Specifically, take the first direction OX as the vertical direction, the second direction YY' as the horizontal direction, the positive pole of the ammeter 160 is connected to the conductive member 140 in the negative direction OY' of the second direction YY', the negative pole of the ammeter 160 is connected to the conductive member 140 in the positive direction OY of the second direction YY', and the vibration direction of the structure to be attenuated is the positive direction of the second direction YY'. The contact area between the negative conductive liquid 180 in the second direction YY' and the negative high charge density component 130 in the second direction YY' is greater than the contact area between the positive conductive liquid 180 in the second direction YY' and the positive high charge density component 130 in the second direction YY'. The positive charge at the contact point between the negative conductive liquid 180 in the second direction YY' and the negative high charge density component 130 in the second direction YY' is greater, and the negative charge at the contact point between the negative high charge density component 130 in the second direction YY' and the negative conductive liquid 180 in the second direction YY' is greater. The positive charge at the contact point between the positive conductive liquid 180 in the second direction YY' and the positive high charge density component 130 in the second direction YY' is greater, and the negative charge at the contact point between the positive high charge density component 130 in the second direction YY' and the positive conductive liquid 180 in the second direction YY' is greater. The current flows counterclockwise. During rotation, the ammeter 160 shows a positive reading. The greater the vibration amplitude, the greater the contact area between the negative conductive liquid 180 in the second direction YY' and the negative high charge density component 130 in the second direction YY', and the smaller the contact area between the positive conductive liquid 180 in the second direction YY' and the positive high charge density component 130 in the second direction YY'. The more positive charges there are at the contact point between the negative conductive liquid 180 in the second direction YY' and the negative high charge density component 130 in the second direction YY', and the more negative charges there are at the contact point between the positive conductive liquid 180 in the second direction YY' and the positive high charge density component 130 in the second direction YY'. As a result, the greater the current, the greater the reading of the ammeter 160, and the smaller the vibration amplitude, the smaller the reading of the ammeter 160. Therefore, the vibration direction can be judged according to the positive or negative of the ammeter 160, and the vibration amplitude can be judged by the size of the reading of the ammeter 160. The permanent magnet 150 will move in the negative direction of the second direction YY' due to inertia, and the magnetic liquid 170 will generate a magnetic force on the permanent magnet 150 to restore the stability of the permanent magnet 150, so that the permanent magnet 150 will have a vibration reduction effect on the vibration reduction structure when moving in the positive direction of the second direction YY'.

[0059] Specifically, self-sensing vibration monitoring is based on the time-varying shielding of the high charge density layer by the double electric layer at the solid-liquid interface. The specific principle is that after the conductive liquid 180 rubs against the surface of the high charge density component 130, the surface of the high charge density component 130 in contact with the conductive liquid 180 is negatively charged. At this time, the negative charge of the surface of the high charge density component 130 in contact with the conductive liquid 180 is shielded by the positive charge in the double electric layer formed at the interface where the conductive liquid 180 and the high charge density component 130 are in contact, while the negative charge of the high charge density component 130 that is not in contact with the conductive liquid 180 is shielded by the positive charge at the conductive component 140 due to electrostatic induction. When the device is stationary, the charge is in a balanced state, and at this time, there is no voltage or current in the external circuit. The contact area between the conductive liquid 180 in the negative direction OY' of the second direction YY' and the high charge density component 130 increases, so that the surface of the high charge density component 130 in contact with the conductive liquid 180 is negatively charged. The contact area between the conductive liquid 180 in the positive direction OY of the second direction YY' and the high charge density component 130 is reduced, so that the surface of the high charge density component 130 in contact with the conductive liquid 180 is positively charged. The positive pole of the ammeter 160 is connected to the conductive component 140 in the negative direction OY' of the second direction YY'. At this time, the current is positive, and the current is negative when vibrating in the opposite direction. The magnitude of the current is related to the contact area between the conductive liquid 180 and the high charge density component 130 on both sides of the second direction YY' in the insulating cavity 121. The greater the vibration amplitude, the greater the increase in the contact area between the conductive liquid 180 and the high charge density component 130 on one side of the second direction YY', resulting in a more negative charge on the surface of the high charge density component 130 in contact with the conductive liquid 180. The greater the decrease in the contact area between the conductive liquid 180 and the high charge density component 130 on the other side of the second direction YY', the more positive charge on the surface of the high charge density component 130 in contact with the conductive liquid 180, and the greater the absolute value of the current.

[0060] Specifically, when the structure to be damped vibrates periodically, the permanent magnet 150 moves periodically, and the ammeter 160 displays a periodic current.

[0061] See Figure 1 In one embodiment, the end faces of the two poles of the permanent magnet 150, the end face of the shell 110 connected to the structure to be damped, and the axis of the insulating tube 120 are parallel, so that the liquid restoring force generated by the conductive liquid 180 returning to a stable state and the component force of the magnetic force of the permanent magnet 150 returning to a stable state along the second direction YY' are maximized, and the vibration reduction effect is better.

[0062] Preferably, the high charge density member 130 is a self-assembled molecular layer containing fluorine atoms or amino groups (—NH 2 ) or a polytetrafluoroethylene polymer film.

[0063] Specifically, the conductive liquid 180 is deionized water, tap water, seawater, various salt solutions, and the like.

[0064] Preferably, the conductive liquid 180 is a 0.001M sodium chloride solution, which can provide an optimal double-layer shielding effect.

[0065] Preferably, the first direction OX is a vertical direction and the second direction YY' is a horizontal direction, so that in a stable state, the contact area between the conductive liquid 180 and the high charge density components 130 on both sides of the second direction YY' is the same, the charge on both sides is the same, there is no current in the circuit composed of the conductive liquid 180, the high charge density components 130, the conductive component 140 and the ammeter 160, and during the vibration process, the liquid restoring force generated by the conductive liquid 180 returning to a stable state and the magnetic force generated by the permanent magnet 150 returning to a stable state along the second direction YY' generate a maximum resultant force, resulting in a better vibration reduction effect.

[0066] Preferably, the insulating tube 120 is a quartz tube. Since the surface of the quartz tube carries little charge, it is less likely to affect the current of the external circuit.

[0067] Specifically, the conductive member 140 is connected to the positive and negative electrodes of the ammeter 160 via a wire 161 by soldering or connecting with an alligator clip.

[0068] Specifically, the conductive member 140 is the base of the high charge density member 130 and the insulating sheet 190 and provides induced charge. The conductive member 140 is a metal film (such as gold, copper, aluminum, etc.) or a conductive silicon sheet with an oxide layer (P100, N100, etc.).

[0069] See Figure 1 In one embodiment, the self-sensing magnetic liquid damping vibration isolator 100 further includes an insulating sheet 190, one side of the insulating sheet 190 is connected to the high charge density member 130, and the other side is connected to the conductive member 140, thereby preventing the surface charge from leaking from the high charge density layer to the conductive substrate.

[0070] Specifically, when the high charge density member 130 itself is made of an insulating material, such as silicon dioxide or rubber, there is no need to add the insulating sheet 190 .

[0071] Specifically, the thickness of the high charge density member 130 along the second direction YY′ is less than 500 μm, thereby preventing the charge flow between the conductive member 140 and the ammeter 160 from being affected due to the excessive thickness of the high charge density member 130 along the second direction YY′.

[0072] Preferably, the thickness of the high charge density member 130 along the second direction YY′ is 50 μm, so as to avoid charge leakage caused by too small thickness of the high charge density member 130 along the second direction YY′.

[0073] See Figure 1In one embodiment, the self-sensing magnetic liquid damping vibration isolator 100 further includes a fixing member 111, one end of the fixing member 111 being connected to an end of the housing 110 away from the structure to be damped, and the other end being connected to the outer wall of the insulating tube 120, so that the insulating tube 120 does not need to be connected to the housing 110 along the entire second direction YY' of the outer wall, thereby facilitating the installation of the conductive member 140, the insulating sheet 190, and the high charge density member 130 at both ends of the insulating tube 120.

[0074] See Figure 1 In one embodiment, the housing 110 includes an end cap 112 and a base 113. The base 113 defines a receiving groove 114, in which the magnetic liquid 170 and the permanent magnet 150 are located. The bottom end of the base 113 is connected to the structure to be damped. The end cap 112 covers the opening of the receiving groove 114 and is detachably connected to the base 113. The side of the end cap 112 away from the base 113 is connected to the outer wall of the insulating tube 120. Therefore, the magnetic liquid 170 and the permanent magnet 150 can be added to the receiving groove 114 after the end cap 112 and the insulating tube 120 are removed. This facilitates the replacement of the magnetic liquid 170 and the maintenance of the interior of the housing 110.

[0075] Specifically, the shape of the containing groove is a regular cylinder or a rectangular parallelepiped, so that the magnetic force of the magnetic liquid on the permanent magnet along the second direction is symmetrical.

[0076] Preferably, the permanent magnet and the accommodating slot are both in the shape of a cuboid, and when the vibration damping structure is stable, the length, width and height of the permanent magnet and the permanent magnet are in equal proportions.

[0077] See Figure 1 In one embodiment, the housing 110 further includes a fastener 115, the end cover 112 is provided with a first through hole 116, and the base 113 is provided with a second through hole 117. The fastener 115 is passed through the first through hole 116 and the second through hole 117 to fasten the end cover 112 to the base 113, so that the end cover 112 can be fastened to the machine base through the fastener 115 while being detachable.

[0078] Specifically, the fasteners 115 are bolts and nuts.

[0079] See Figure 1 In one embodiment, the housing 110 further includes a sealing ring 118 , which is located between the end cover 112 and the base 113 and is used to seal the gap between the end cover 112 and the base 113 , thereby preventing the magnetic liquid 170 from leaking.

[0080] See Figure 1In one embodiment, the end cover 112 includes a main body 1121 and a positioning portion 1122. The main body 1121 is covered on an end of the base 113 away from the structure to be vibrated. The positioning portion 1122 is arranged on an end of the main body 1121 close to the structure to be vibrated and extends into the receiving groove 114. The positioning portion 1122 is adapted to the opening of the receiving groove 114, so that when the end cover 112 is covered on the opening of the receiving groove 114, the positioning portion 1122 extends into the receiving groove 114 to position the end cover 112 and the receiving groove 114, thereby facilitating the covering of the end cover 112.

[0081] See Figure 1 In one embodiment, a bevel groove 1123 is provided on the side of the positioning portion 1122 close to the structure to be damped. The opening of the bevel groove 1123 faces the structure to be damped. The groove walls of the bevel groove 1123 include a first groove wall 1124 and a second groove wall 1125 that are inclined to each other. The first groove wall 1124 is arranged on one side of the second groove wall 1125 along the second direction YY'. Therefore, when the structure to be damped vibrates along the second direction YY', the magnetic fluid 170 is driven to shake along the second direction YY' and collides with the first groove wall 1124 or the second groove wall 1125, thereby receiving a reaction force, causing the magnetic fluid 170 to return to a stable state more quickly.

[0082] An embodiment of the present application further provides a method for preparing a self-sensing magnetic liquid damping vibration absorber 100, wherein the method for preparing the self-sensing magnetic liquid damping vibration absorber 100 comprises the following steps:

[0083] S100: 3D print the housing 110 and the insulation tube 120 and connect them.

[0084] S200: cutting and cleaning the conductive member 140 .

[0085] S300 : forming a high charge density member 130 on a surface of the conductive member 140 .

[0086] S400: Clean the surface of the conductive member 140 again.

[0087] S500 : Connecting the two electrodes of the ammeter 160 to the two conductive members 140 respectively to form an external circuit.

[0088] S600: Connecting a conductive member 140 containing a high charge density member 130 to each end of the insulating tube 120, and adding a conductive liquid 180 into the insulating cavity 121, and then sealing the insulating tube 120 with the conductive member 140 and the high charge density layer.

[0089] S700 : placing the magnetic liquid 170 and the permanent magnet 150 into the housing 110 .

[0090] Preparation method of self-sensing magnetic liquid damping vibration absorber 100 The above-mentioned self-sensing magnetic liquid damping vibration absorber 100 is used to prepare the shell 110 and the insulating tube 120 in combination with 3D printing technology, and the bottom mortgage and high charge density component 130 are manually prepared. Then, the conductive liquid 180 is added to the insulating cavity 121, the ammeter 160 and the conductive liquid 180 are connected, and the magnetic liquid 170 and the permanent magnet 150 are added to the shell 110. Therefore, through simple operation and preparation, a self-sensing magnetic liquid damping vibration absorber 100 that can simultaneously perform vibration monitoring and vibration reduction can be obtained.

[0091] refer to Figure 4 Combined with Figure 1 In one embodiment, the steps of the preparation method of the self-sensing magnetic liquid damping vibration absorber 100 are as follows:

[0092] S100: 3D print the housing 110 and the insulation tube 120 and connect them.

[0093] S200: Cut and clean the P100 conductive silicon wafer containing an oxide layer. The oxide layer of the P100 conductive silicon wafer can serve as an insulating sheet 190 to prevent surface charge leakage from the self-assembled molecular layer. The portion of the P100 conductive silicon wafer other than the oxide layer can serve as a conductive element 140 to provide induced charge.

[0094] S300: Use a mixed solution of concentrated sulfuric acid and hydrogen peroxide with a volume ratio of 7:3 to treat the P100 conductive silicon wafer to hydroxylate the P100 conductive silicon wafer. A large number of hydroxyl groups exist on the surface after treatment, which is conducive to subsequent reactions with molecules and the realization of molecular self-assembly.

[0095] S400: Place the treated P100 conductive silicon wafer in a vacuum drying oven. Simultaneously, place 1g of 1H,1H,2H,2H-perfluorodecyltriethoxysilane in a small flask and place it in the vacuum drying oven. Under vacuum conditions, the 1H,1H,2H,2H-perfluorodecyltriethoxysilane reacts with the hydroxyl groups on the surface of the previously treated P100 conductive silicon wafer, causing molecular self-assembly to produce high-charge density components 130. 1H,1H,2H,2H-perfluorodecyltriethoxysilane is only one type of silane coupling agent. Its beneficial effect lies in the fluorine atoms in its molecules, which impart a high negative charge to the self-assembled molecules. 1H,1H,2H,2H-perfluorodecyltriethoxysilane can be replaced by silane coupling agents containing fluorine atoms or amino groups.

[0096] S500: Clean P100 conductive silicon wafers to remove residual impurities.

[0097] S600: Connect the conductive member 140 of the P100 conductive silicon wafer to the metal wire 161 and the ammeter 160 to form an external circuit.

[0098] S700 : Connecting the P100 conductive silicon wafer containing the self-assembled molecular layer (high charge density element 130 ) to the insulating tube 120 .

[0099] S800: Add 12 mL of the conductive liquid 180 into the insulating cavity 121 . The specific volume of the conductive liquid 180 should be changed according to actual working conditions.

[0100] S900: 12g of magnetic liquid 170 and permanent magnet 150 are installed into the housing 110. Under the test bench experimental conditions in the figure, 12g of magnetic liquid 170 has a good vibration reduction effect.

[0101] refer to Figure 4 Combined with Figure 1 In another embodiment, the steps of the preparation method of the self-sensing magnetic liquid damping vibration absorber 100 are as follows:

[0102] S100: 3D print the housing 110 and the insulation tube 120 and connect them.

[0103] S200: Cutting and cleaning polytetrafluoroethylene as a high charge density layer. Compared with conductive silicon wafers, the use of polytetrafluoroethylene significantly reduces the preparation cost.

[0104] S300: bonding the conductive member 140 to the bottom of the polytetrafluoroethylene, wherein the conductive base is a copper tape with a lower cost, and connecting the conductive base with the copper wire 161 and the ammeter 160 to form an external circuit.

[0105] S400: Bonding polytetrafluoroethylene and copper tape together to connect them to the insulating tube 120 .

[0106] S500 : Add 9 mL of liquid into the insulating cavity 121 .

[0107] S600 : 8 g of magnetic liquid 170 and permanent magnet 150 are placed into the housing 110 .

[0108] Specifically, Figure 4 Figure 3 shows the influence of the volume of the conductive liquid 180 and the mass of the magnetic liquid 170 on the vibration reduction effect. The horizontal axis represents the mass of the magnetic liquid 170, and the vertical axis represents the vibration attenuation time. The shorter the vibration attenuation time, the better the vibration reduction effect. The symbols in the legend represent different volumes of the same conductive liquid 180.

[0109] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0110] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A self-sensing magnetic liquid damping shock absorber for installation on a structure to be damped, characterized in that: The self-sensing magnetic liquid damping vibration isolator comprises: a shell, an insulating tube, two high charge density parts, two conductive parts, a permanent magnet, and an ammeter; The shell contains a magnetic liquid, and the permanent magnet is immersed in the magnetic liquid; one end of the shell along the first direction is connected to the structure to be damped, and the other end of the shell along the first direction is connected to the outer wall of the insulating tube; The two magnetic poles of the permanent magnet are arranged along a first direction; One of the high charge density components is respectively provided at both ends of the insulating tube along the second direction, and the side wall of the insulating tube and the two high charge density components form an insulating cavity; the insulating cavity partially contains a conductive liquid, and the two high charge density components are respectively connected to one of the conductive components on the sides facing away from each other along the second direction; the two conductive components are respectively electrically connected to the positive and negative poles of the ammeter; the second direction is set at an angle to the first direction, and the second direction is the tube length direction of the insulating tube.

2. The self-sensing magnetic liquid damping vibration absorber according to claim 1, characterized in that: The end faces of the two magnetic poles of the permanent magnet, the end face of the shell connected to the structure to be damped, and the axis of the insulating tube are parallel.

3. The self-sensing magnetic liquid damping vibration absorber according to claim 1, characterized in that: The self-sensing magnetic liquid damping vibration isolator further includes an insulating sheet, one side of which is connected to the high charge density component, and the other side of which is connected to the conductive component.

4. The self-sensing magnetic liquid damping vibration absorber according to claim 1, characterized in that: The self-sensing magnetic liquid damping vibration isolator further includes a fixing member, one end of which is connected to an end of the shell away from the structure to be damped, and the other end of which is connected to the outer wall of the insulating tube.

5. The self-sensing magnetic liquid damping vibration absorber according to claim 1, characterized in that: The housing includes an end cover and a base; The base is provided with a receiving groove, and the magnetic liquid and the permanent magnet are located in the receiving groove; The bottom end of the base is connected to the structure to be attenuated, the end cover covers the opening of the accommodating groove and is detachably connected to the base, and the side of the end cover away from the base is connected to the outer wall of the insulating tube.

6. The self-sensing magnetic liquid damping vibration absorber according to claim 5, characterized in that: The shell further includes a fastener. The end cover is provided with a first through hole, and the base is provided with a second through hole. The fastener is passed through the first through hole and the second through hole to fasten the end cover to the base.

7. The self-sensing magnetic liquid damping vibration absorber according to claim 5, characterized in that: The housing further comprises a sealing ring, which is located between the end cover and the base and is used to seal a gap between the end cover and the base.

8. The self-sensing magnetic liquid damping vibration absorber according to claim 5, characterized in that: The end cover includes a body and a positioning portion. The body cover is arranged at an end of the base away from the structure to be damped. The positioning portion is arranged at an end of the body close to the structure to be damped and extends into the receiving groove. The positioning portion is adapted to the opening of the receiving groove.

9. The self-sensing magnetic liquid damping vibration absorber according to claim 8, characterized in that: A bevel groove is provided on a side of the positioning portion close to the structure to be vibrated; an opening of the bevel groove faces the structure to be vibrated; The groove wall of the inclined groove includes a first groove wall and a second groove wall that are inclined to each other, and the first groove wall is arranged on one side of the second groove wall along the second direction.

10. A method for preparing a self-sensing magnetic liquid damping vibration absorber, for preparing the self-sensing magnetic liquid damping vibration absorber according to any one of claims 1 to 9, characterized in that: The preparation method of the self-sensing magnetic liquid damping vibration absorber comprises the following steps: 3D printing the shell and the insulating tube and connecting them; cutting and cleaning the conductive member; forming the high charge density member on the surface of the conductive member; cleaning the surface of the conductive member again; connecting the two electrodes of the ammeter to the two conductive members respectively to form an external circuit; Connecting the two ends of the insulating tube to the conductive member containing the high charge density member, respectively, and simultaneously adding the conductive liquid into the insulating cavity; The magnetic liquid and the permanent magnet are placed in the shell.

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