A piezoelectric vibration sensor and vibration monitoring system

Abstract

This invention discloses a piezoelectric vibration sensor and a vibration monitoring system. The piezoelectric vibration sensor includes a housing and a magnetic levitation structure disposed within the housing. A first fixed magnet and a second fixed magnet are disposed on two opposite sides within the housing. The magnetic levitation structure includes: a first substrate, on which a first moving magnet is disposed, with the first moving magnet and the first fixed magnet facing each other and their opposing magnetic poles repelling each other; a second substrate, disposed vertically opposite to the first substrate, on which a second moving magnet is disposed, with the second moving magnet and the second fixed magnet facing each other and their opposing magnetic poles repelling each other; an elastic element comprising multiple layers of elastic helical beams, with both ends of the elastic element abutting against the first substrate and the second substrate, respectively; and a piezoelectric element disposed in each layer of the elastic helical beams.

Description

Technical Field

[0001] This invention relates to the field of piezoelectric vibration sensor technology, and more particularly to a piezoelectric vibration sensor and vibration monitoring system. Background Technology

[0002] Vibration sensors are devices that measure the magnitude of object vibration, converting vibration signals into electrical signals. They are widely used in health status monitoring fields such as marine environments, machinery, large civil structures, and transport vehicles. With the rapid development of the Internet of Things (IoT), the number and distribution of sensors are increasing, while traditional sensors are mainly powered by batteries. In production practice, the traditional battery-powered mode has revealed drawbacks such as limited lifespan, high environmental pollution risks, and low equipment maintainability, making it difficult to address the problem of the explosive growth of distributed sensors. Therefore, a sustainable power supply method needs to be developed to overcome the constraints of traditional power sources.

[0003] In recent years, piezoelectric energy harvesting devices have been gradually applied to fields such as energy harvesting and sensors due to their advantages of simple and compact structure, ease of manufacturing and strong anti-interference ability. However, the existing piezoelectric energy harvesting devices have high and single resonant frequencies, resulting in a small effective operating frequency range, which reduces the energy harvesting efficiency and vibration detection sensitivity of the device.

[0004] Therefore, how to improve energy harvesting efficiency and vibration detection sensitivity is a technical problem that needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a piezoelectric vibration sensor to improve energy harvesting efficiency and vibration detection sensitivity.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A piezoelectric vibration sensor includes a housing and a magnetic levitation structure disposed within the housing, wherein a first fixed magnet and a second fixed magnet are disposed on two opposite sides within the housing;

[0008] The magnetic levitation structure includes:

[0009] A first substrate, on which a first movable magnet is disposed, wherein the first movable magnet and a first fixed magnet are disposed opposite each other and the two opposing magnetic poles of the first movable magnet and the first fixed magnet repel each other.

[0010] The second substrate is arranged from top to bottom opposite to the first substrate. A second moving magnet is provided on the second substrate. The second moving magnet and the second fixed magnet are arranged opposite to each other and the two magnetic poles of the second moving magnet and the second fixed magnet repel each other.

[0011] The elastic element is provided with multiple layers of elastic helical beams, and the two ends of the elastic element abut against the first substrate and the second substrate respectively;

[0012] Piezoelectric elements are disposed on the elastic helical beams in each layer.

[0013] Optionally, in the above-mentioned piezoelectric vibration sensor, the magnetic levitation structure further includes a guide shaft, the first substrate and the second substrate are both slidably engaged with the guide shaft, and the elastic element is provided with a through hole through which the guide shaft can pass.

[0014] Optionally, in the above-mentioned piezoelectric vibration sensor, a first linear bearing and a second linear bearing are provided on the guide shaft, the first linear bearing being located between the guide shaft and the first substrate, and the second linear bearing being located between the guide shaft and the second substrate;

[0015] The first substrate and the first moving magnet are both disposed on the first linear bearing, and the second substrate and the second moving magnet are both disposed on the second linear bearing.

[0016] Optionally, in the above-mentioned piezoelectric vibration sensor, the housing includes a housing body and a cover plate detachably connected to the housing body;

[0017] The cover plate is provided with a first mounting part for installing the first fixed magnet, and the inner wall of the housing body opposite to the cover plate is provided with a second mounting part for installing the second fixed magnet.

[0018] Optionally, in the above-mentioned piezoelectric vibration sensor, the elastic element includes a metal ring with multiple peaks and valleys, and the elastic coefficient of the elastic element is changed by changing the diameter, number of layers and thickness of the metal ring.

[0019] Optionally, in the above-mentioned piezoelectric vibration sensor, the piezoelectric element includes a piezoelectric single crystal, a piezoelectric ceramic, lead zirconate titanate, barium titanate, polyvinylidene fluoride piezoelectric film, or other materials with piezoelectric properties.

[0020] A vibration monitoring system includes a piezoelectric vibration sensor as described above.

[0021] Optionally, in the above-mentioned vibration monitoring system, the piezoelectric element of the piezoelectric vibration sensor includes multiple power supply piezoelectric elements, which are connected in series and then electrically connected to a rectifier and a capacitor in sequence.

[0022] Optionally, in the above-described vibration monitoring system, the piezoelectric element of the piezoelectric vibration sensor further includes a monitoring piezoelectric element, and the piezoelectric vibration sensor further includes:

[0023] A microprocessor, connected to the monitoring piezoelectric element, is used to receive and process the output signal of the monitoring piezoelectric element;

[0024] An information converter, connected to the microprocessor, is used to receive the output signal of the microprocessor and convert the received signal into at least one of the frequency information, acceleration information and amplitude information of the vibration.

[0025] An alarm is electrically connected to the information converter.

[0026] Optionally, in the above vibration monitoring system, the microprocessor and the information converter are connected via a wireless transmission module, and both the microprocessor and the wireless transmission module are electrically connected to the capacitor.

[0027] When using the piezoelectric vibration sensor provided by this invention, when the piezoelectric vibration sensor vibrates up and down, the magnetic levitation structure disposed within the housing also vibrates up and down, causing the elastic element to deform, thereby driving the piezoelectric elements disposed on each elastic helical beam to vibrate up and down. Based on the fact that the first moving magnet and the first fixed magnet are arranged opposite each other and their two opposing magnetic poles repel each other, and the second moving magnet and the second fixed magnet are arranged opposite each other and their two opposing magnetic poles repel each other, during the up and down vibration of the piezoelectric vibration sensor, the first fixed magnet and the second fixed magnet generate a magnetic repulsive force on the magnetic levitation structure, increasing the frequency of the up and down vibration of the magnetic levitation structure, thereby increasing the deformation frequency of the piezoelectric elements disposed on the elastic helical beam, achieving the effect of frequency upscaling, converting low-frequency vibration into high-frequency output, and improving energy harvesting efficiency and vibration detection sensitivity.

[0028] Therefore, it can be seen that by setting elastic elements in the magnetic levitation structure, the stiffness of the entire magnetic levitation structure is reduced, thereby lowering the resonant frequency and enabling it to better match the external vibration frequency. Furthermore, since the piezoelectric elements are set on the elastic helical beams of the elastic elements, the stress conditions of each layer of elastic helical beams are different. Therefore, the vibration conditions of each layer of piezoelectric elements are different, and they have different resonant frequencies. By superimposing the resonant frequencies of multiple layers of piezoelectric elements, the effective operating frequency range of the device can be widened, further improving the energy harvesting efficiency and vibration detection sensitivity. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the internal structure of a piezoelectric vibration sensor provided in an embodiment of the present invention;

[0031] Figure 2 This is a schematic diagram of a magnetic levitation structure provided in an embodiment of the present invention;

[0032] Figure 3 This is a schematic diagram of the mounting structure of a first fixed magnet on a cover plate according to an embodiment of the present invention;

[0033] Figure 4 This is a schematic diagram of the mounting structure of a second linear bearing provided in an embodiment of the present invention;

[0034] Figure 5 A vibration monitoring system based on a piezoelectric vibration sensor is provided in an embodiment of the present invention;

[0035] Figure 6 This is a schematic diagram of a vibration alarm trigger provided in an embodiment of the present invention.

[0036] Among them, 100 is the shell, 101 is the shell body, 102 is the cover plate, 103 is the first fixed magnet, 104 is the second fixed magnet, 200 is the magnetic levitation structure, 201 is the first substrate, 202 is the first moving magnet, 203 is the second substrate, 204 is the second moving magnet, 205 is the elastic element, 206 is the piezoelectric element, 2061 is the power supply piezoelectric element, 2062 is the monitoring piezoelectric element, 207 is the guide shaft, 208 is the first linear bearing, 209 is the second linear bearing, 300 is the rectifier, 400 is the capacitor, 500 is the microprocessor, 600 is the wireless transmission module, and 700 is the information converter. Detailed Implementation

[0037] In view of this, the core of the present invention is to provide a piezoelectric vibration sensor to improve energy harvesting efficiency and vibration detection sensitivity.

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] like Figures 1 to 3 As shown, an embodiment of the present invention discloses a piezoelectric vibration sensor, including a housing 100 and a magnetic levitation structure 200 disposed within the housing 100. A first fixed magnet 103 and a second fixed magnet 104 are disposed on two opposite sides within the housing 100. The magnetic levitation structure 200 includes a first substrate 201, a second substrate 203, an elastic element 205, and a piezoelectric element 206.

[0040] The first substrate 201 is provided with a first moving magnet 202, which is disposed opposite to a first fixed magnet 103 and the two opposing magnetic poles of the first moving magnet 202 and the first fixed magnet 103 repel each other; the second substrate 203 is disposed opposite to the first substrate 201 from top to bottom, and a second moving magnet 204 is provided on the second substrate 203, which is disposed opposite to a second fixed magnet 104 and the two opposing magnetic poles of the second moving magnet 204 and the second fixed magnet 104 repel each other; the elastic element 205 is provided with multiple layers of elastic spiral beams, and the two ends of the elastic element 205 abut against the first substrate 201 and the second substrate 203 respectively; the piezoelectric element 206 is disposed on each layer of elastic spiral beams.

[0041] When using the piezoelectric vibration sensor provided by this invention, when the piezoelectric vibration sensor vibrates up and down, the magnetic levitation structure 200 disposed in the housing 100 also vibrates up and down, causing the elastic element 205 to deform, thereby driving the piezoelectric elements 206 disposed on each elastic helical beam to vibrate up and down. Based on the fact that the first moving magnet 202 and the first fixed magnet 103 are arranged opposite each other and their two opposing magnetic poles repel each other, and the second moving magnet 204 and the second fixed magnet 104 are arranged opposite each other and their two opposing magnetic poles repel each other, during the up and down vibration of the piezoelectric vibration sensor, the first fixed magnet 103 and the second fixed magnet 104 generate a magnetic repulsive force on the magnetic levitation structure 200, increasing the frequency of the up and down vibration of the magnetic levitation structure 200, and thus increasing the deformation frequency of the piezoelectric elements 206 disposed on the elastic helical beam, achieving the effect of frequency upscaling, converting low-frequency vibration into high-frequency output, and improving energy harvesting efficiency and vibration detection sensitivity.

[0042] Therefore, it can be seen that by setting the elastic element 205 in the magnetic levitation structure 200, the stiffness of the entire magnetic levitation structure 200 is reduced, thereby lowering the resonant frequency and enabling it to better match the external vibration frequency. Furthermore, since the piezoelectric element 206 is set on each layer of elastic helical beam of the elastic element 205, the stress condition of each layer of elastic helical beam is different. Therefore, the vibration condition of each layer of piezoelectric element 206 is different, and it has a different resonant frequency. By superimposing the resonant frequencies of multiple layers of piezoelectric element 206, the effective operating frequency range of the device can be widened, further improving the energy harvesting efficiency and vibration detection sensitivity.

[0043] It should be noted that the above-mentioned elastic element 205 can be a spring, a metal sheet, or other elastic element 205 with a special structure. As long as the type of elastic element 205 can meet the usage requirements, it is within the protection scope of this invention. Optionally, the elastic element 205 provided in the embodiment of this invention is a metal ring with multiple peaks and valleys. By changing the diameter, number of layers, and thickness of the metal ring, the elastic coefficient of the elastic element 205 can be changed, thereby adjusting the stiffness of the entire piezoelectric vibration sensor.

[0044] In addition, the first fixed magnet 103, the second fixed magnet 104, the first moving magnet 202, the second moving magnet 204, the first substrate 201, the second substrate 203 and the elastic spiral beam are coaxially arranged so that the elastic spiral beam produces a deformation that is linearly related to the vibration, and the output signal generated by the piezoelectric element 206 has a good linear relationship with the vibration.

[0045] Specifically, the vibration frequency experienced by the piezoelectric vibration sensor has a good linear relationship with the frequency of the voltage signal generated by the piezoelectric element 206, and the vibration amplitude and acceleration experienced by the piezoelectric vibration sensor have a good linear relationship with the amplitude of the voltage signal generated by the piezoelectric element 206. Therefore, the piezoelectric vibration sensor can simultaneously detect the vibration frequency, amplitude and acceleration information.

[0046] Furthermore, the aforementioned magnetic levitation structure 200 also includes a guide shaft 207. The first substrate 201 and the second substrate 203 are both slidably engaged with the guide shaft 207. The elastic element 205 is provided with a through hole through which the guide shaft 207 can pass, so as to guide the first substrate 201, the second substrate 203, and the elastic element 205 through the guide shaft 207, ensuring that the magnetic levitation structure 200 only moves up and down in a direction parallel to the axial direction of the guide shaft 207, and preventing the vibration direction of the magnetic levitation structure 200 from deviating.

[0047] Furthermore, both the first substrate 201 and the second substrate 203 can achieve sliding engagement with the guide shaft 207 through methods such as slider-slide groove engagement or slider-guide rail engagement. Any assembly method that meets the usage requirements falls within the protection scope of this invention. Optionally, the guide shaft 207 provided in this embodiment of the invention is provided with a first linear bearing 208 and a second linear bearing 209. The first linear bearing 208 is located between the guide shaft 207 and the first substrate 201, and the second linear bearing 209 is located between the guide shaft 207 and the second substrate 203, so that the first linear bearing 208 and the second linear bearing 209 can move axially along the guide shaft 207 with lower friction. Moreover, the first substrate 201 and the first moving magnet 202 are disposed on the first linear bearing 208, and the second substrate 203 and the second moving magnet 204 are disposed on the second linear bearing 209, so that during vibration, the first substrate 201 and the first moving magnet 202 move up and down with the first linear bearing 208, and the second substrate 203 and the second moving magnet 204 move up and down with the second linear bearing 209.

[0048] like Figure 1 As shown, the aforementioned housing 100 includes a housing body 101 and a cover plate 102 detachably connected to the housing body 101. After the housing body 101 and the cover plate 102 are connected, they enclose the internal space of the housing 100, and the magnetic levitation structure 200 is disposed in the internal space.

[0049] Specifically, the cover plate 102 is provided with a first mounting part for mounting a first fixing magnet 103, and the inner wall of the housing body 101 opposite to the cover plate 102 is provided with a second mounting part for mounting a second fixing magnet 104.

[0050] It should be understood that the aforementioned housing body 101 and cover plate 102 can be connected together by snap-fit ​​or threaded connection, and any connection method that can achieve detachable connection is within the protection scope of this invention; Optionally, the housing body 101 and cover plate 102 provided in the embodiments of this invention are connected by thread, which has a simple structure and is easy to assemble.

[0051] In addition, the first mounting part and the second mounting part mentioned above can both be grooves or countersunk holes, etc. Any structural form that can meet the installation requirements is within the protection scope of this invention; optionally, the first mounting part and the second mounting part provided in the embodiments of this invention are both groove structures.

[0052] The piezoelectric element 206 provided by the present invention includes piezoelectric single crystal, piezoelectric ceramic, lead zirconate titanate, barium titanate, polyvinylidene fluoride piezoelectric film or other materials with piezoelectric properties, so that the piezoelectric element 206 will exhibit a piezoelectric effect under the action of mechanical force.

[0053] In addition, the present invention also discloses a vibration monitoring system, including the piezoelectric vibration sensor as described above. Therefore, it has all the technical effects of the piezoelectric vibration sensor mentioned above, which will not be described in detail here.

[0054] Furthermore, in the aforementioned vibration monitoring system, the piezoelectric element 206 of the piezoelectric vibration sensor includes multiple power-supplying piezoelectric elements 2061. These multiple power-supplying piezoelectric elements 2061 are connected in series and then electrically connected to the rectifier 300 and the capacitor 400 in sequence. This allows the electric baton output from the multiple power-supplying piezoelectric elements 2061 to be rectified and stored in the capacitor 400, thus powering other electronic components, such as the wireless transmission module 600 and the microprocessor 500 described below. This enables the entire vibration monitoring system to achieve long-term, continuous self-powering without a power source, eliminating the need to consider power supply issues during use. This solves the problem of traditional power constraints and broadens the application scope.

[0055] like Figure 5 and Figure 6 As shown, the piezoelectric element 206 of the piezoelectric vibration sensor also includes a monitoring piezoelectric element 2062, and the piezoelectric vibration sensor also includes a microprocessor 500, an information converter 700, and an alarm.

[0056] The microprocessor 500 is signal-connected to the monitoring piezoelectric element 2062 and is used to receive and process the output signal of the monitoring piezoelectric element 2062 to obtain the amplitude and frequency information of the voltage signal. The information converter 700 is signal-connected to the microprocessor 500 and is used to receive the output signal of the microprocessor 500 and convert the received signal into at least one of the frequency information, acceleration information and amplitude information of the vibration. The alarm is electrically connected to the information converter 700 and is used to issue an alarm signal when one of the vibration frequency, acceleration and amplitude exceeds a preset value.

[0057] It should be noted that the information converter 700 described above can be equipped with a receiving end and information conversion software. The receiving end is used to receive the output signal of the microprocessor, and the information conversion software processes the information based on the signal received by the receiving end, converting it into information on the frequency, acceleration and amplitude of the vibration. In some embodiments of the present invention, the information conversion software is LabVIEW programming software.

[0058] In addition, the microprocessor 500 and the information converter 700 can be connected by a signal line or a wireless transmission module. Any signal transmission method that meets the usage requirements is within the scope of protection of this invention. Optionally, the microprocessor 500 and the information converter 700 provided in this embodiment of the invention are connected by a wireless transmission module 600, and both the microprocessor 500 and the wireless transmission module 600 are electrically connected to the capacitor 400 to construct a vibration monitoring system based on a self-powered voltage-type vibration sensor, thereby eliminating the dependence on traditional electricity and broadening the application scenarios.

[0059] Furthermore, the aforementioned alarm can be a buzzer alarm, a light alarm, or a combination of sound and light alarm, etc. Any type of alarm that meets the usage requirements falls within the protection scope of this invention.

[0060] The terms "first" and "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units may include steps or units not listed, but rather steps or units not listed.

[0061] The above description of the disclosed embodiments will enable those skilled in the art to make or use various modifications of these embodiments. It will be readily apparent to those skilled in the art that the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A piezoelectric vibration sensor, characterized in that, It includes a housing and a magnetic levitation structure disposed within the housing, wherein a first fixed magnet and a second fixed magnet are disposed on two opposite sides within the housing; The magnetic levitation structure includes: A first substrate, on which a first movable magnet is disposed, wherein the first movable magnet and a first fixed magnet are disposed opposite each other and the two opposing magnetic poles of the first movable magnet and the first fixed magnet repel each other. The second substrate is arranged from top to bottom opposite to the first substrate. A second moving magnet is provided on the second substrate. The second moving magnet and the second fixed magnet are arranged opposite to each other and the two magnetic poles of the second moving magnet and the second fixed magnet repel each other. The elastic element is provided with multiple layers of elastic helical beams, and the two ends of the elastic element abut against the first substrate and the second substrate respectively; Piezoelectric elements are disposed on the elastic helical beams in each layer; The piezoelectric elements in each layer vibrate differently and have different resonant frequencies.

2. The piezoelectric vibration sensor according to claim 1, characterized in that, The magnetic levitation structure also includes a guide shaft, and both the first substrate and the second substrate are slidably engaged with the guide shaft. The elastic element is provided with a through hole through which the guide shaft can pass.

3. The piezoelectric vibration sensor according to claim 2, characterized in that, The guide shaft is provided with a first linear bearing and a second linear bearing, the first linear bearing being located between the guide shaft and the first substrate, and the second linear bearing being located between the guide shaft and the second substrate; The first substrate and the first moving magnet are both disposed on the first linear bearing, and the second substrate and the second moving magnet are both disposed on the second linear bearing.

4. The piezoelectric vibration sensor according to claim 1, characterized in that, The housing includes a housing body and a cover plate detachably connected to the housing body; The cover plate is provided with a first mounting part for installing the first fixed magnet, and the inner wall of the housing body opposite to the cover plate is provided with a second mounting part for installing the second fixed magnet.

5. The piezoelectric vibration sensor according to claim 1, characterized in that, The piezoelectric element includes a piezoelectric single crystal, a piezoelectric ceramic, or a polyvinylidene fluoride piezoelectric film.

6. A vibration monitoring system, characterized in that, Including the piezoelectric vibration sensor as described in any one of claims 1 to 5.

7. The vibration monitoring system according to claim 6, characterized in that, The piezoelectric vibration sensor includes multiple power-supplying piezoelectric elements, which are connected in series and then electrically connected to a rectifier and a capacitor in sequence.

8. The vibration monitoring system according to claim 7, characterized in that, The piezoelectric element of the piezoelectric vibration sensor also includes a monitoring piezoelectric element, and the piezoelectric vibration sensor further includes: A microprocessor, connected to the monitoring piezoelectric element, is used to receive and process the output signal of the monitoring piezoelectric element; An information converter, connected to the microprocessor, is used to receive the output signal of the microprocessor and convert the received signal into at least one of the frequency information, acceleration information and amplitude information of the vibration. An alarm is electrically connected to the information converter.

9. The vibration monitoring system according to claim 8, characterized in that, The microprocessor and the information converter are connected via a wireless transmission module, and both the microprocessor and the wireless transmission module are electrically connected to the capacitor.

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