A three-dimensional piezoelectric fiber acoustic sensor based on axial polarization

Abstract

The application provides a kind of three-dimensional piezoelectric fiber acoustic sensor based on axial polarization, comprising: first shell, second shell, hanger, filler, piezoelectric accelerometer and electrode device;Second shell is fixed in first shell by hanger, and the filler is filled between the second shell and the first shell;Piezoelectric accelerometer includes communication block, three polarized piezoelectric fibers, balancing piece and acoustic signal receiving ball, communication block is supported in the second shell by support column, three polarized piezoelectric fibers are mutually orthogonal, and one end is fixed on communication block, the other end is connected with acoustic signal receiving ball through second shell along first direction, second direction and third direction respectively, and the balancing piece is fixed on the communication block;The electrode device is wrapped on the surface of the polarized piezoelectric fiber.The sensor structure of the application is small, can detect low frequency signal, and has high sensitivity to acoustic signal, and is suitable for industrial production.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of acoustic devices and piezoelectric sensors, and particularly relates to a three-dimensional piezoelectric fiber acoustic sensor based on axial polarization. BACKGROUND

[0002] A piezoelectric sensor is a transducer that converts acoustic signals in the application environment into electrical signals. With the development of science and technology, various platforms have higher and higher requirements for acoustic device detection. Traditional piezoelectric sensors have large rigidity and are difficult to effectively sense low-frequency acoustic signals. Most of the sensors cannot measure three-dimensional acoustic signals, so they cannot achieve high-precision and high-sensitivity measurement in the working environment.

[0003] Therefore, it is a problem to be solved by those skilled in the art to provide a new three-dimensional piezoelectric fiber acoustic sensor. SUMMARY

[0004] In view of the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide a three-dimensional piezoelectric fiber acoustic sensor based on axial polarization, which is used to solve the technical problems of the piezoelectric sensor in the prior art, such as low-frequency sensitivity performance is not ideal, is easily disturbed during work, and can only detect one-dimensional direction signal.

[0005] To achieve the above-mentioned purposes and other related purposes, the present application provides a three-dimensional piezoelectric fiber acoustic sensor based on axial polarization, which comprises at least: a first shell, a second shell, a suspension, a filler, a piezoelectric accelerometer and an electrode device.

[0006] The second shell is fixed in the first shell by the suspension, and the filler is filled between the second shell and the first shell.

[0007] The piezoelectric accelerometer comprises a communication block, three polarized piezoelectric fibers, a balancing piece and an acoustic signal receiving ball. The communication block is supported in the second shell by a support column. The three polarized piezoelectric fibers are orthogonal to each other, one end is fixed on the communication block, and the other end is connected with the acoustic signal receiving ball through the second shell along the first direction, the second direction and the third direction respectively. The balancing piece is fixed on the communication block.

[0008] The electrode device is wrapped on the surface of the polarized piezoelectric fiber.

[0009] As a preferred scheme of the present application, the electrode device comprises a first electrode layer, an insulating layer and a second electrode layer. The first electrode layer is wrapped on the surface of one end of the polarized piezoelectric fiber. The insulating layer is wrapped on the surface of a part of the first electrode layer and the polarized piezoelectric fiber. The second electrode layer is wrapped on the surface of the insulating layer and the polarized piezoelectric fiber.

[0010] As a preferred scheme of the present application, the sensor further comprises charge amplification devices, which are electrically connected with the first electrode layer and the second electrode layer respectively and connected to external devices through lead wires in the first shell upper port.

[0011] As a preferred scheme of the present application, the material of the first electrode layer comprises Ag, the material of the second electrode layer comprises Ag, the material of the insulating layer comprises TiO2, and the material of the polarized piezoelectric fiber comprises PZT piezoelectric ceramic.

[0012] As a preferred scheme of the present application, the balancing piece comprises two non-polarized piezoelectric fibers in the direction opposite to the first direction and the second direction.

[0013] As a preferred scheme of the present application, the length of the non-polarized piezoelectric fiber is greater than the length of the polarized piezoelectric fiber.

[0014] As a preferred scheme of the present application, the first shell and the second shell are concentric and both are cubes.

[0015] As a preferred scheme of the present application, the polarization mode and the structural size of the three polarized piezoelectric fibers are the same.

[0016] As a preferred scheme of the present application, the sound signal receiving ball comprises a hollow foam ball.

[0017] As a preferred scheme of the present application, the suspension piece comprises a combination of one or both of a spring and a rubber rope.

[0018] As described above, the three-dimensional piezoelectric fiber acoustic sensor based on axial polarization of the present application has the following beneficial effects:

[0019] 1. The present application uses the piezoelectric fiber with axial polarization as the sensitive element of the sensor, and greatly improves the sensitivity of the sensor by using the high piezoelectricity of the piezoelectric fiber.

[0020] 2. The present application orthogonally fixes the piezoelectric fiber with axial polarization on the communication block, so that the sensor can receive sound signals in all directions.

[0021] 3. The sound signal receiving ball of the present application can effectively increase the sensitive area of the polarized piezoelectric fiber for receiving sound signals.

[0022] 4. The present application uses the damping and energy dissipation effect of the suspension piece (such as a spring damper) to make the sensor quickly recover to a stable state after receiving sound signals, reduce the interference of the surrounding environment and other factors, and improve the detection accuracy of the sensor. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1Fig. 1 is a schematic diagram of an axial polarization-based three-dimensional piezoelectric fiber acoustic sensor according to the present application.

[0024] Figure 2 Fig. 2 is a three-dimensional schematic diagram of a piezoelectric accelerometer in the axial polarization-based three-dimensional piezoelectric fiber acoustic sensor according to the present application.

[0025] Figure 3 Fig. 3 is a sectional view of an electrode device in the axial polarization-based three-dimensional piezoelectric fiber acoustic sensor according to the present application.

[0026] Figure 4 Fig. 4 is a top view of the axial polarization-based three-dimensional piezoelectric fiber acoustic sensor according to the present application.

[0027] Element No. Explanation

[0028] 1 first housing

[0029] 2 second housing

[0030] 3 suspension

[0031] 4 filler

[0032] 5 piezoelectric accelerometer

[0033] 51 connecting block

[0034] 52 polarized piezoelectric fiber

[0035] 53 balancing member

[0036] 54 acoustic signal receiving ball

[0037] 6 electrode device

[0038] 61 first electrode layer

[0039] 62 insulating layer

[0040] 63 second electrode layer

[0041] 7 support column

[0042] 8 charge amplification device

[0043] 9 filler port

[0044] 10 port DETAILED DESCRIPTION

[0045] The present application is described in detail below with specific reference being made to certain embodiments. Those skilled in the art will readily understand other advantages and benefits of the present application from the following description, taken in connection with the accompanying drawings. The present application can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and fully convey the scope of the application to those skilled in the art.

[0046] Please refer to the drawings. It should be noted that the drawings provided in the embodiments only schematically illustrate the basic concepts of the present application, and only the components related to the present application are shown in the drawings, rather than being drawn according to the number, shape and size of the components in actual implementation. The actual implementation of each component can be a random change, and the component layout pattern can be more complex.

[0047] As shown in Figures 1-4 The present application provides a kind of three-dimensional piezoelectric fiber acoustic sensor based on axial polarization, the sensor mainly includes: first shell 1, second shell 2, suspension 3, filler 4, piezoelectric accelerometer 5 and electrode device 6. The second shell 2 is fixed in the first shell 1 by the suspension 3, and the second shell 2 and the first shell 1 are filled with the filler 4; The piezoelectric accelerometer 5 includes communication block 51, three polarized piezoelectric fibers 52, balancing piece 53 and acoustic signal receiving ball 54, the communication block 51 is supported in the second shell 2 by support column 7, three the polarized piezoelectric fibers 52 are orthogonal to each other, and one end is fixed on the communication block 51, and the other end is connected with the acoustic signal receiving ball 54 along the first direction, the second direction and the third direction respectively, the balancing piece 53 is fixed on the communication block 51; The electrode device 6 is wrapped on the surface of the polarized piezoelectric fiber 52.

[0048] As an example, the first shell 1 can be a cuboid frame. The second shell 2 is arranged in the interior of the first shell 1 and is also a cuboid. Preferably, the second shell 2 is arranged concentrically with the first shell 1. In addition, the materials of the first shell 1 and the second shell 2 are not limited, and it is required to have high stiffness and mass. The first shell 1 and the second shell 2 preferably adopt epoxy resin composite material.

[0049] Further, the eight corners of the first shell 1 and the eight corners of the second shell 2 are connected by the suspension 3 to stably suspend the second shell 2 in the center of the first shell 1.

[0050] As an example, the suspension 3 includes one or a combination of the other of spring and rubber rope, for example, it can be spring or rubber rope. Of course, in other embodiments, it can also be other suitable suspension components with damping and energy dissipation effect, as long as the device can provide motion resistance to reduce the motion ability of the object. In the present embodiment, the suspension 3 is preferably a spring, which utilizes the damping and energy dissipation effect of the spring damper to quickly restore the sensor to a stable state after receiving the acoustic signal, reduce the interference of the surrounding environment and other factors, and thus improve the detection accuracy of the sensor.

[0051] The filler 4 is filled between the first shell 1 and the second shell 2, the filler 4 is selected to be similar to the density of the sensor working environment, and the filler 4 should have neutral characteristics and not have adverse effects on the material, so that the sound signal can be transmitted to the piezoelectric accelerometer 5 through the filler 4 medium as much as possible.

[0052] As an example, as shown in Figure 4 The first shell 1 is provided with a filling port 9 at the top, through which the filler 4 can be filled between the first shell 1 and the second shell 2, and after filling, the filling port 9 is closed by a bolt.

[0053] The piezoelectric accelerometer 5 is supported in the second shell 2, specifically through the support column 7 to support and fix the communication block 51, so as to fix the piezoelectric accelerometer 5. The support column 7 has a certain weight, which can effectively solve the problem that the piezoelectric accelerometer 5 is light and easy to be disturbed by the environment.

[0054] It should be noted that as an example, the first direction can be the X-axis direction, the second direction can be the Y-axis direction, and the third direction can be the Z-axis direction, that is, the three polarization piezoelectric fibers 52 are fixed on the communication block 51 along the X, Y and Z axis directions. In order to better play a supporting role, the support column 7 is located in the opposite direction of the Z axis.

[0055] The balance piece 53 is used to balance the three polarization piezoelectric fibers 52. As a preferred structure, the balance piece 53 includes two non-polarized piezoelectric fibers in the opposite direction of the first direction and the second direction, that is, one non-polarized piezoelectric fiber is arranged in the opposite direction of the X axis, and the other non-polarized piezoelectric fiber is arranged in the opposite direction of the Y axis.

[0056] In order to maintain balance, the length of the non-polarized piezoelectric fiber needs to be slightly longer than that of the polarization piezoelectric fiber 52, and the purpose is to maintain balance with the polarization piezoelectric fiber 52, and the specific length is determined according to the weight of the sound signal receiving ball 54.

[0057] The sound signal receiving ball 54 is fixed to the end face of the polarization piezoelectric fiber 52 and is in physical contact with the filler 4. The sound signal receiving ball 54 can effectively increase the area of the polarization piezoelectric fiber 52 receiving the sound signal, but the size of the sound signal receiving ball 54 cannot be too large, and cannot exceed the load bearing range of the polarization piezoelectric fiber 52. As an example, the sound signal receiving ball 54 is preferably a hollow foam ball, of course, in other embodiments, other suitable spherical bodies can also be selected to increase the area of the sound signal receiving ball 54 and improve the test sensitivity of the sensor.

[0058] As an example, three of the polarized piezoelectric fibers 52 are axially polarized piezoelectric fibers, which are polarized in the same way and have the same size structure, and the axial polarized piezoelectric fibers 52 are orthogonal to each other, so that they can receive sound signals in all directions.

[0059] The electrode device 6 is used to lead out the electrical properties of the polarized piezoelectric fibers 52, which will be converted into electrical signals, i.e. positive and negative electrical signals, after receiving acoustic vibration waves. The positive and negative electrical signals are led out to the charge amplification device 8 through the electrode device 6.

[0060] As an example, as shown in Figure 3 The electrode device 6 includes a first electrode layer 61, an insulating layer 62, and a second electrode layer 63. The first electrode layer 61 is wrapped around the surface of one end of the polarized piezoelectric fiber 52, the insulating layer 62 is wrapped around the first electrode layer 61 and part of the surface of the polarized piezoelectric fiber 52, and the second electrode layer 63 is wrapped around the insulating layer 62 and the surface of the polarized piezoelectric fiber 52.

[0061] Specifically, the first electrode layer 61 in the electrode device 6 is the innermost layer. A silver target material is sputtered onto a PZT piezoelectric ceramic substrate by a magnetron sputtering process, wherein the PZT ceramic substrate is the polarized piezoelectric fiber 52. After the silver target material is sputtered onto the target position of the PZT ceramic substrate, the first electrode layer 61 is formed, which wraps a part (about 30%) of the polarized piezoelectric fiber. Then, a TiO2 target material is sputtered onto the silver substrate by a magnetron sputtering process, and TiO2 is used as the insulating layer 62, which wraps a part (20%-80%) of the first electrode layer. The protruding part of the first electrode layer 61 not wrapped by the insulating layer 62 can lead out a metal lead wire. Finally, a silver target material is sputtered onto the TiO2 substrate by a magnetron sputtering process, and the silver layer formed by the sputtering of the silver target material is used as the second electrode layer 63, which wraps the entire insulating layer 62 and the polarized piezoelectric fiber 52. Then, a lead wire is led out on the first electrode layer 61 and the second electrode layer 63, respectively, as the positive and negative electrodes of the sensor. One end of the two electrodes is connected to the polarized piezoelectric fiber 52, and the other end is electrically connected to the charge amplification device 8 through a lead wire, and the charge amplification device 8 is connected to an external device (not shown in the figure) through the lead wire in the port 10 of the first shell 1, as shown in the attached Figure 4 As shown in the figure, so as to complete the analysis of the sound signal.

[0062] The charge amplification device 8 can amplify the electrical signals collected by the piezoelectric accelerometer 51, so as to avoid the situation that the equipment cannot detect due to the too weak collected electrical signals.

[0063] It should be noted that the above electrode device 6 is only an example, and the material of the electrode layer 61, 63 can be any conductive material other than Ag, and the material of the insulating layer 62 can be any insulating material other than TiO2, which is not limited here. The method for preparing the electrode layer 61, 63 and the insulating layer 62 is also not limited, and in addition to magnetron sputtering, other suitable process methods can also be used.

[0064] The application principle of the axial polarization-based three-dimensional piezoelectric fiber acoustic sensor provided by the application is as follows: when an acoustic signal propagates to the first shell 1, the first shell 1 transmits the vibration caused by the acoustic signal to the filler 4, the filler 4 has a density close to that of the acoustic signal receiving ball 54 and can be regarded as a whole, the acoustic signal receiving ball 54 transmits the vibration caused by the received acoustic signal to the polarized piezoelectric fiber 52, the polarized piezoelectric fiber 52 converts the acoustic signal into an electric signal when subjected to the vibration caused by the acoustic signal, and finally the electric signal is led out to the electric charge amplification device 8 through the lead wire of the electrode device 6, and then the electric signal is analyzed by an external device.

[0065] In summary, the axial polarization-based three-dimensional piezoelectric fiber acoustic sensor provided by the application can detect low-frequency signals in all directions, and has high sensitivity to acoustic signals. In addition, the sensor has a simple and compact structure and is suitable for industrial mass production.

[0066] Therefore, the application effectively overcomes the shortcomings of the prior art and has high industrial utilization value.

[0067] The above embodiments only exemplarily illustrate the principles and effects of the application, and are not used to limit the application. Any person skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the application. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical thought of the application should be covered by the claims of the application.

Claims

1. A three-dimensional piezoelectric fiber acoustic sensor based on axial polarization, characterized in that, The sensor includes at least: a first housing, a second housing, a suspension component, a filler, a piezoelectric accelerometer, and an electrode device; The second housing is fixed inside the first housing by the suspension member, and the space between the second housing and the first housing is filled with the filler. The piezoelectric accelerometer includes a connecting block, three polarized piezoelectric fibers, a balancing element, and an acoustic signal receiving ball. The connecting block is supported in the second housing by a support column. The three polarized piezoelectric fibers are orthogonal to each other, with one end fixed to the connecting block and the other end passing through the second housing and connected to the acoustic signal receiving ball along the first direction, the second direction, and the third direction, respectively. The balancing element is fixed to the connecting block. The electrode device is wrapped around the surface of the polarized piezoelectric fiber.

2. The three-dimensional piezoelectric fiber acoustic sensor based on axial polarization according to claim 1, characterized in that: The electrode device includes a first electrode layer, an insulating layer, and a second electrode layer. The first electrode layer is wrapped around the surface of one end of the polarized piezoelectric fiber. The insulating layer is wrapped around the first electrode layer and a portion of the surface of the polarized piezoelectric fiber. The second electrode layer is wrapped around the insulating layer and the surface of the polarized piezoelectric fiber.

3. The three-dimensional piezoelectric fiber acoustic sensor based on axial polarization according to claim 2, characterized in that: The sensor also includes a charge amplification device, which is electrically connected to the first electrode layer and the second electrode layer respectively, and is connected to an external device through a lead in the port of the first housing.

4. The axially polarized three-dimensional piezoelectric fiber acoustic sensor according to claim 2 or 3, characterized in that: The material of the first electrode layer includes Ag, the material of the second electrode layer includes Ag, the material of the insulating layer includes TiO2, and the material of the polarized piezoelectric fiber includes PZT piezoelectric ceramic.

5. The three-dimensional piezoelectric fiber acoustic sensor based on axial polarization according to claim 1, characterized in that: The balancing element comprises two unpolarized piezoelectric fibers in directions opposite to the first and second directions.

6. The three-dimensional piezoelectric fiber acoustic sensor based on axial polarization according to claim 5, characterized in that: The length of the unpolarized piezoelectric fiber is greater than the length of the polarized piezoelectric fiber.

7. The three-dimensional piezoelectric fiber acoustic sensor based on axial polarization according to claim 1, characterized in that: The first shell and the second shell are concentric and both are cubes.

8. The three-dimensional piezoelectric fiber acoustic sensor based on axial polarization according to claim 1, characterized in that: The three polarized piezoelectric fibers described above have the same polarization mode and structural dimensions.

9. The three-dimensional piezoelectric fiber acoustic sensor based on axial polarization according to claim 1, characterized in that: The acoustic signal receiving ball comprises a hollow foam ball.

10. The three-dimensional piezoelectric fiber acoustic sensor based on axial polarization according to claim 1, characterized in that: The suspension component includes one or a combination of springs and rubber cords.

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