JP7316706B1 - Piezoelectric Vibration Electricity Converter and Piezoelectric Vibration Electricity Conversion Method - Google Patents

Abstract

Kind Code: A1 A piezoelectric vibration-to-electricity converter that does not require an amplifier and a power supply, is inexpensive, and has high durability is provided. A piezoelectric vibration electric converter W1 for converting vibration of an object 1 into an electric signal includes a vibration plate 10 having a piezoelectric element 12 attached to a substantially central portion of a flat plate 11, and a vibration plate 10 installed on the object 1. Also, elastic first diaphragm support parts 20, 20 that support both ends, the vicinity thereof, or the periphery of the diaphragm 10, and a second diaphragm that is installed on the object 1 and supports the substantially central part of the diaphragm 10. It has a plate support portion 30 and a weight 50 attached to the diaphragm 10, and strain is generated in the diaphragm 1 by the inertial force of the weight 50 due to vibration of the object 1, and the piezoelectric element 12 converts the strain into an electric signal. It is designed to convert. [Selection drawing] Fig. 1

Description

The present invention relates to a piezoelectric vibration electrical converter and a piezoelectric vibration electrical conversion method, and more particularly, to a piezoelectric vibration electrical converter and a piezoelectric vibration electrical conversion method for converting vibration of an object into an electrical signal using a piezoelectric element.

Conventionally, various types of vibration sensors have been used for vibration measurement of objects such as structures and devices. For example, the vibration sensor may be strain or piezoelectric. Moreover, in recent years, MEMS sensors configured by electric circuits have also been put to practical use as vibration sensors.

In addition, Patent Document 1 proposes a piezoelectric vibration sensor provided with a laminated body in which a film-shaped piezoelectric element and a reinforcing member are laminated. In this piezoelectric vibration sensor, one end of the laminate is cantilevered and a weight is applied to the other end of the laminate, and bending stress acts on the laminate due to vibration. By doing so, an electric signal is generated from the piezoelectric element.

Japanese Patent No. 6170388

By the way, the conventional techniques described above each have the following problems.
Specifically, many of the "strain or piezoelectric vibration sensors" require amplifiers for converting vibrations into electrical signals. In addition, this vibration sensor has been devised in various ways in order to have characteristics such as linearity in the detection range and flatness of the frequency response. ing.

MEMS sensors also have the problem that they require a power supply to operate. Therefore, when the MEMS sensor is used in an installation environment where a wired power supply is not possible, a storage battery, a generator, or the like must be provided.
Further, in the piezoelectric vibration sensor described in Patent Document 1, one end of a laminate in which a film-shaped piezoelectric element and a reinforcing material are laminated is supported by a cantilever, and the other end of the laminate is supported by a cantilever. It adopts a configuration in which a weight is loaded on the Such a configuration in which a weight is attached to the other end of the laminate, one of which is supported by a cantilever, has the problem of low durability against vibration and a short product life due to its structure.
For example, if the above piezoelectric vibration sensor needs to be installed in a large number of locations and is used for long-term vibration detection, the frequency of replacement will increase, and the operation will be difficult. It takes a lot of effort and costs.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and its object is to provide a piezoelectric vibration electric converter and a piezoelectric vibration electric conversion method which do not require an amplifier and a power supply, are inexpensive and have high durability. be.

The present invention for solving the above-mentioned problems is a piezoelectric vibration-electricity converter that includes a piezoelectric element and converts the vibration of an object into an electric signal, comprising: a vibration plate having the piezoelectric element attached substantially in the center thereof; an elastic first diaphragm supporting portion that is installed on the object and supports both ends, the vicinity thereof, or the periphery of the diaphragm; and a substantially central portion of the diaphragm that is installed on the object and supports It has a second diaphragm supporting portion for supporting and a weight attached to the diaphragm, and the inertial force of the weight caused by the vibration of the object generates strain in the diaphragm, so that the piezoelectric element self-supports. It is characterized in that the generated strain is converted into an electric signal.

As described above, according to the above configuration of the present invention, the inertia force of the weight can efficiently and greatly deform the diaphragm to which the piezoelectric element is attached, thereby generating a large strain. An electrical signal corresponding to the vibration of the object can be obtained. As a result, according to the above configuration of the present invention, there is provided a piezoelectric vibration-to-electricity converter capable of detecting vibration without providing an amplifier. Further, the piezoelectric vibration-electricity converter of the present invention uses a piezoelectric element to convert the vibration of an object into an electric signal, so unlike the MEMS sensor described above, it does not require a power source.
That is, according to the above configuration of the present invention, it is possible to provide an inexpensive piezoelectric vibration electric converter that does not require an amplifier or a power supply.

In addition, in the present invention, the diaphragm having the piezoelectric element attached to the substantially central portion supports the first elastic diaphragm support portion which supports both ends, the vicinity thereof, or the periphery thereof, and the substantially central portion thereof. It is installed on the object via the second diaphragm support portion. With this configuration, the diaphragm bends around the attachment position of the piezoelectric element.
The reason why the "elastic first diaphragm supporting portion" is provided to support both ends of the diaphragm and the vicinities or surroundings thereof is as follows.
Specifically, it is also possible to provide only the second diaphragm support portion that supports the substantially central portion of the diaphragm without providing the first diaphragm support portion.
However, in the case where only the second diaphragm supporting portion that supports the substantially central portion of the diaphragm is configured, there arises a problem that the diaphragm is not stably supported.
Further, if only the second diaphragm supporting portion that supports the substantially central portion of the diaphragm is configured, there is a possibility that peaks and valleys of the vibration characteristics of the diaphragm become large. In particular, if the diaphragm is made of a material such as metal that has a low damping characteristic, the Q value (quality factor, vibration amplification factor) increases, and the frequency response characteristic of the output voltage against vibration deteriorates (peaks and valleys are large and uneven). )do. In order to improve this frequency response characteristic, it is conceivable to impart damping characteristics to the diaphragm itself, but it is generally not easy to do so by changing the material of the diaphragm itself.
Therefore, in the present invention, the support of the diaphragm is stabilized by providing the first diaphragm support portion that supports both ends, the vicinity thereof, or the periphery of the diaphragm. In addition, in the present invention, by providing the first diaphragm support portion, it is possible to impart elastic characteristics and damping to the first diaphragm support portion. It is possible to adjust the response characteristics.

In addition, in the present invention, since the diaphragm is supported by the first diaphragm supporting portion and the second diaphragm supporting portion, the diaphragm (a film-like piezoelectric element and a reinforcing member laminated together) as described in Patent Document 1 described above can be used. It has a structure with high durability compared to the one in which the laminated body is supported in a cantilever manner. Therefore, for example, the piezoelectric vibration-to-electricity converter of the present invention can be used as a "device (equipment) having a drive unit that generates vibration", "a moving object such as a railway vehicle or automobile", or "a structure such as a building or road". Even if it is used for applications such as vibration measurement, etc., the frequency of replacement can be reduced, and the labor and cost required for these administrators can be suppressed.

Also, the weight may be formed as an integral body extending over both ends of the diaphragm.
In this way, by setting the weight across both ends of the diaphragm, the inertial force of the weight acts on the diaphragm symmetrically about the second diaphragm supporting portion that supports the substantially central portion of the diaphragm. effect to be obtained. In addition, since the weight is formed as a single body extending over both ends of the diaphragm, the number of parts can be reduced.

Also, the weights may be attached to both ends or the peripheral edge of the diaphragm.
According to the above configuration, the vibration of the diaphragm can be effectively amplified by the weight.

The present invention also provides a piezoelectric vibration-to-electricity converter that includes a piezoelectric element and converts the vibration of an object into an electric signal, comprising: a vibration plate having the piezoelectric element attached to a substantially central portion thereof; a base formed of a magnetic material installed in the base, a first diaphragm support portion of an elastic body that is installed on the base and supports both ends, the vicinity thereof, or the periphery of the diaphragm, and the base mounted on the and a second diaphragm supporting portion that supports a substantially central portion of the diaphragm, and a weight attached to the upper surface of the diaphragm, wherein the diaphragm is distorted by the inertial force of the weight caused by the vibration of the object. is generated and the strain generated in the piezoelectric element itself is converted into an electric signal. The outer periphery of the weight is covered with a case formed of a hollow box-shaped magnetic material, and at least one of the weight, the diaphragm, and the case has a magnet that amplifies the vibration of the diaphragm. is attached.

According to the above configuration of the present invention, it is possible to provide a piezoelectric vibration electric converter that does not require an amplifier and a power supply, is inexpensive, and has high durability.
Furthermore, in the above configuration of the present invention, a base made of a magnetic material and placed on the object is provided. Further, the “base, first diaphragm support portion, second diaphragm support portion, diaphragm and weight” are covered with a case formed of a hollow box-shaped magnetic material. At least one of the weight, the diaphragm and the case is attached with a magnet for amplifying the vibration of the diaphragm.
According to this configuration, the vibration of the diaphragm can be amplified by the influence of the magnetic attraction force, and the vibration can be efficiently converted into an electric signal.

Further, the present invention is a piezoelectric vibration-to-electricity conversion method for converting vibration of an object into an electric signal using a piezoelectric element, wherein the piezoelectric element is attached to a substantially central portion of a flat plate to form a vibration plate, Through a first elastic diaphragm supporting portion that supports both ends, the vicinity thereof, or the periphery of the diaphragm, and a second diaphragm supporting portion that supports a substantially central portion of the diaphragm, the object is Further, a weight is attached to the diaphragm, strain is generated in the diaphragm by the inertial force of the weight due to vibration of the object, and the strain generated in the piezoelectric element itself is output as an electric signal. It is characterized by converting to

According to the present invention, it is possible to provide an inexpensive and highly durable piezoelectric vibration electric converter and a piezoelectric vibration electric conversion method that do not require an amplifier and a power supply.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram for demonstrating the structure of the piezoelectric vibration electric converter of 1st Embodiment of this invention, and the schematic diagram which looked at the piezoelectric vibration electric converter from the side is shown. 1 is a schematic diagram of a piezoelectric vibration electric transducer according to a first embodiment of the present invention viewed from below; FIG. FIG. 3 is a schematic diagram for explaining a flat plate and piezoelectric elements that constitute the diaphragm of the first embodiment of the present invention, and a weight support attached to the upper surface of the diaphragm; FIG. 10 is a schematic diagram for explaining the configuration of the piezoelectric vibration electric converter of the second embodiment of the present invention, and shows a schematic view of the piezoelectric vibration electric converter viewed from the side. FIG. 11 is a schematic diagram for explaining the configuration of the piezoelectric vibration electric converter of the third embodiment of the present invention, and shows a schematic view of the piezoelectric vibration electric converter viewed from the side. The size of the frequency response function of the output voltage of the piezoelectric element when the piezoelectric vibration electric transducer of the first embodiment of the present invention is attached to the vibration table and vibrated, and the vibration plate without weights mounted only with both end supports. FIG. 4 is a schematic diagram showing the magnitude of the frequency response function of the output voltage of the piezoelectric element when it is attached to a vibration table and vibrated.

Hereinafter, piezoelectric vibration electrical converters W1, W2, and W3 of embodiments (first embodiment, second embodiment, and third embodiment) of the present invention will be described with reference to the drawings.
The piezoelectric vibration-electric converters W1, W2, and W3 of the present embodiment use the piezoelectric element 12 to "apparatus (equipment) having a drive unit that generates vibration", "moving objects such as railway vehicles and automobiles", or It is a device that converts the vibration of an object 1 such as "a structure such as a building or a road" into an electric signal.
The piezoelectric vibration electric transducers W1, W2, and W3 are used, for example, to measure the vibration of devices, moving bodies, or structures, or are installed on roads, railroad tracks, etc., and are used to measure vibrations when automobiles and railways pass by. It is used in power generation systems that generate electricity in

<<1st Embodiment>>
First, the piezoelectric vibration electric converter of the first embodiment will be described with reference to FIGS. 1 to 3. FIG.
Here, FIG. 1 is a schematic diagram for explaining the configuration of the piezoelectric vibration electric converter of the first embodiment, and shows a schematic side view of the piezoelectric vibration electric converter. FIG. 2 is a schematic diagram of the piezoelectric vibration electrical transducer of the first embodiment viewed from below. FIG. 3 is a schematic diagram for explaining the flat plate and the piezoelectric element that constitute the diaphragm of the first embodiment, and the weight support attached to the upper surface of the diaphragm.

The piezoelectric vibration electric converter W1 of the first embodiment employs a configuration in which one weight 50 is placed across both ends of the diaphragm 10 to which the piezoelectric element 12 is attached.
Specifically, as shown in FIG. 1, the piezoelectric vibration electric converter W1 of the first embodiment includes a vibration plate 10 having a piezoelectric element 12 attached to a substantially central portion of a flat plate 11, a device, a moving body, or a structure. First diaphragm support parts (both end support members) 20, 20 which are installed on an object 1 such as an object and support both ends of the diaphragm 10, and a substantially central part of the diaphragm 10 which is installed on the object 1. It has a second diaphragm support portion (central support member) 30 for supporting and a weight 50 attached to the diaphragm 10 .
The lower end portions of the first diaphragm support portions 20 and 20 and the second diaphragm support portion 30 are installed and fixed to the object 1 . Further, the first diaphragm support portions 20, 20 are made of an elastic material such as rubber.

Further, in the first embodiment, weight support portions 40 and 40 are attached to both ends of the upper surface (surface) of the diaphragm 10 . The weight 50 is placed on weight support portions (weight support members) 40 , 40 and attached to the diaphragm 10 via the weight support portions 40 , 40 .
An output line 70 is attached to the piezoelectric element 12 for outputting an "electrical signal converted from strain".
Hereinafter, the configuration of the piezoelectric vibration electric converter W1 will be described in order.

For example, as shown in FIGS. 1 and 2, the first diaphragm support portions 20, 20 that support both ends of the diaphragm 10 are formed in an elongated rectangular parallelepiped shape (square prism shape), and the upper surface thereof vibrates. It is attached to both ends of the back surface of the plate 10 (left and right ends in the illustrated example). Further, the lower ends of the first diaphragm supporting portions 20, 20 are attached to the object 1 so that they can be fixed.

In the illustrated example, the first diaphragm support portions 20, 20 are formed in an elongated rectangular parallelepiped shape (square prism shape), but the shape is not limited to this shape. The first diaphragm support portions 20, 20 may have any shape as long as the lower end thereof can be fixed to the object 1 and both ends of the diaphragm 10 can be supported.
In addition, in the illustrated example, the first diaphragm support parts 20, 20 are attached to both ends of the diaphragm 10, but they may be attached to positions other than both ends. For example, the first diaphragm supports 20, 20 may be attached near or around both ends of the diaphragm 10, and may be configured to support near or around both ends of the diaphragm 1. .
Further, the diaphragm 10 may be attached to the first diaphragm support parts 20, 20 in a state of overhanging from the first diaphragm support parts 20, 20, as shown in FIG. 5, which will be described later.

1 and 2, for example, the second diaphragm support part 30 is formed in a substantially columnar shape, and the upper surface thereof is attached to the substantially central part of the rear surface of the diaphragm 10. As shown in FIGS. Further, the second diaphragm support part 30 is attached to the object 1 at its lower end so that the second diaphragm support part 30 can be fixed. The second diaphragm support 30 is made of a solid material such as metal, for example.
In addition, in the illustrated example, the second diaphragm support portion 30 is formed in a cylindrical shape, but it is not particularly limited to this. The second diaphragm support part 30 may have any shape as long as the lower end part can be fixed to the object 1 and the substantially central part of the diaphragm 10 can be supported.

Also, the piezoelectric element 12 constituting the diaphragm 10 is made of piezoelectric ceramic (for example, PZT (lead zirconate titanate)) or the like.
Further, the flat plate 11 forming the diaphragm 10 is made of a material such as metal or synthetic resin.
Then, as shown in FIG. 3, the piezoelectric element 12 is adhered to the substantially central portion of the upper surface of the flat plate 11 and firmly joined.

In the example shown in FIG. 3, the piezoelectric element 12 is formed in a circular sheet shape in a plan view, but the shape of the piezoelectric element 12 is appropriately designed. For example, the piezoelectric element 12 may be formed in a polygonal sheet shape in plan view.
The flat plate 11 is made of metal or synthetic resin, for example, but may be made of any material other than metal or synthetic resin as long as it can firmly join the piezoelectric element 12 .
Further, although the diaphragm 10 of the first embodiment has a configuration in which the piezoelectric element 12 is attached to the flat plate 11, the object to which the piezoelectric element 12 is attached does not necessarily have to be a flat plate.

1 and 3, the weight support portions 40, 40 are formed in an elongated rectangular parallelepiped shape (square prism shape), and both ends of the upper surface of the diaphragm 10 (left and right ends in the illustrated example) are formed. part). The weight supports 40, 40 are made of, for example, an elastic or solid material.

Also, the weight 50 is formed as an integral body extending over both ends of the diaphragm 10, and is mounted on the weight support parts 40, 40 so as to span both ends of the diaphragm 10. . That is, in the first embodiment, one weight 50 is placed across both ends of the diaphragm 10 to which the piezoelectric element 12 is attached.

The piezoelectric vibration-electricity converter W1 configured as described above causes strain to be generated in the vibration plate 10 by the inertial force of the weight 50 due to the vibration of the object 1, and the strain generated in the piezoelectric element 12 itself (self) is converted into electricity. It is designed to convert into a signal. Also, the electric signal converted by the piezoelectric element 12 is output to an external device (not shown) via the output line 70 .

As described above, according to the configuration of the piezoelectric vibration electric converter W1 of the first embodiment, the inertial force of the weight 50 efficiently and largely deforms the diaphragm 10 to which the piezoelectric element 12 is attached, thereby generating a larger strain. can be made Therefore, according to the configuration of the first embodiment, it is possible to acquire an electric signal corresponding to the vibration of the object 1 without providing an amplifier. Further, the piezoelectric vibration electric converter W1 of the first embodiment uses the piezoelectric element 12 attached to the flat plate 11 to convert the vibration of the object 1 into an electric signal. is not necessary.
Therefore, according to the first embodiment, there is provided a piezoelectric vibration-to-electricity converter W1 that can measure vibration without providing an amplifier or power supply, or that can be used in a power generation system.

Further, in the above-described first embodiment, the diaphragm 10 to which the piezoelectric element 12 is affixed substantially in the central portion has the elastic first diaphragm support portions 20, 20 supporting both ends thereof, and the substantially central portion thereof. It is installed on the object 1 via a second diaphragm support portion 30 that supports the portion. According to this configuration, the diaphragm 10 bends around the attachment position of the piezoelectric element 12 .

Further, in the first embodiment, both ends of the diaphragm 10 are supported by the first diaphragm support portions 20, 20 for the following reasons.
Specifically, it is also possible to provide a configuration in which only the second diaphragm support portion 30 that supports the substantially central portion of the diaphragm 10 is provided without providing the first diaphragm support portions 20 , 20 .
However, if only the second diaphragm support portion 40 that supports the substantially central portion of the diaphragm 10 is configured, there arises a problem that the support of the diaphragm 10 is unstable.
Furthermore, in this case, there is a possibility that peaks and valleys of the vibration characteristics of the diaphragm 10 become large. In particular, when the diaphragm 10 is made of a material such as metal that has a small damping characteristic, the Q value (quality factor, vibration amplification factor) increases, and the frequency response characteristic of the output voltage to vibration deteriorates (peaks and valleys are large and uneven). )do. In order to improve this frequency response characteristic, it is conceivable to give damping characteristics to the diaphragm 10 alone, but it is generally not easy to change the material of the diaphragm 10 itself.

Therefore, in the first embodiment, both ends of the diaphragm 10 are supported by the first diaphragm support portions 20, 20, thereby stabilizing the support of the diaphragm 10. FIG.
In the first embodiment, both ends of the diaphragm 10 are supported by the first diaphragm support parts 20, 20, thereby imparting elastic characteristics and damping to the first diaphragm support parts 20, 20. make it possible to As a result, according to the first embodiment, it is possible to adjust the frequency response characteristics without changing the structures of the diaphragm 10 and the piezoelectric element 12 .

Further, in the first embodiment, since the diaphragm 10 is supported by the first diaphragm support portions 20, 20 and the second diaphragm support portion 30, the diaphragm (film-like piezoelectric element) as described in Patent Document 1 described above can be used. It has a structure with high durability compared to a structure in which a laminated body in which an element and a reinforcing member are laminated) is supported by a cantilever. That is, the piezoelectric vibration electric converter W1 of the first embodiment has a structure that is less likely to break down than that of Patent Document 1 described above.
Therefore, for example, even when the piezoelectric vibration electric transducer W1 is used for vibration measurement of a device, a moving body, or a structure, the frequency of replacement can be reduced, and the labor and labor required for the administrator can be reduced. You can keep costs down.
In addition, for example, the piezoelectric vibration electric converter W1 is laid on roads, railroad tracks, etc., and it is necessary to install it in many places, such as a power generation system that generates power by vibration when automobiles and railroad vehicles pass. Moreover, even when used for long-term installation, the labor and cost of the administrator can be reduced.
Furthermore, since the piezoelectric vibration electric converter W1 of the first embodiment does not require power supply, there is no need to provide power supply equipment or to replace batteries.

Further, in the first embodiment, the weight 50 is attached to the diaphragm 10 via the weight support portions 40 , 40 attached to both ends of the upper surface of the diaphragm 10 . Also, the weight 50 is formed as an integrated body extending over both ends of the diaphragm 10 .
Since the weights 50 are arranged over both ends of the diaphragm 10 in this manner, the inertial force of the weights 50 acts symmetrically on the diaphragm 10 with respect to the central support portion 30. can get. In addition, since the weight 50 is formed as a single body extending over both ends of the diaphragm 10, the number of parts can be reduced.

Thus, according to the first embodiment, it is possible to provide the piezoelectric vibration electric converter W1 and the piezoelectric vibration electric conversion method which do not require an amplifier and a power supply, are inexpensive and have high durability.

<<Second embodiment>>
Next, the piezoelectric vibration electric converter W2 of the second embodiment will be described with reference to FIG.
Here, FIG. 4 is a schematic diagram for explaining the configuration of the piezoelectric vibration electric converter of the second embodiment, and shows a schematic side view of the piezoelectric vibration electric converter.
The piezoelectric vibration electric converter W2 of the second embodiment is obtained by partially modifying the configuration of the piezoelectric vibration electric converter W1 of the first embodiment. Therefore, among the configurations of the piezoelectric vibration electric converter W2 of the second embodiment, the same configurations as those of the first embodiment are denoted by the same reference numerals, and descriptions thereof are omitted or simplified.

The piezoelectric vibration electric converter W2 of the second embodiment has a configuration in which weights 52, 52 are respectively placed on both ends of the diaphragm 10 to which the piezoelectric element 12 is attached (two weights 52, 52 are placed on the diaphragm 10). configuration).
Specifically, as shown in FIG. 4, the piezoelectric vibration electric converter W2 of the second embodiment includes a vibration plate 10 having a piezoelectric element 12 attached to a substantially central portion of a flat plate 11, and an object 1. Also, first diaphragm support parts 20, 20 that support both ends of the diaphragm 10, a second diaphragm support part 30 that is installed on the object 1 and supports substantially the central part of the diaphragm 10, and the diaphragm 10 It has weights 52, 52 attached to the ends thereof.

The piezoelectric vibration electric converter W2 of the second embodiment does not provide the weight support part 40 on the upper surface of the diaphragm 10, and the upper surface and both ends of the diaphragm 10 (in the example shown in FIG. 4, both left and right ends). , respectively, are directly attached with weights 52,52.
The weights 52 , 52 are formed, for example, in the shape of an elongated rectangular parallelepiped (quadrangular prism), and attached to both ends (left and right ends in the illustrated example) of the upper surface of the diaphragm 10 . Also, the weights 52, 52 are formed of individual objects unlike the weight 50 of the first embodiment.

In the configuration of the piezoelectric vibration electric transducer W2 of the second embodiment, as in the first embodiment, strain is generated in the vibration plate 10 by the inertial force of the weights 52, 52 due to the vibration of the object 1, and the piezoelectric element 12 is displaced. The strain generated in itself is converted into an electric signal, and the converted electric signal is output to an external device (not shown) via the output line 70 .

As described above, in the second embodiment, similarly to the first embodiment, it is possible to provide the piezoelectric vibration electric converter W2 and the piezoelectric vibration electric conversion method that do not require an amplifier and a power supply, are inexpensive, and have high durability. can.

<<Third Embodiment>>
Next, the piezoelectric vibration electric converter W3 of the third embodiment will be described with reference to FIG.
Here, FIG. 5 is a schematic diagram for explaining the configuration of the piezoelectric vibration electric converter of the third embodiment, and shows a schematic side view of the piezoelectric vibration electric converter.
The piezoelectric vibration electric converter W3 of the third embodiment is obtained by partially modifying the configuration of the piezoelectric vibration electric converter W1 of the first embodiment. Therefore, among the configurations of the piezoelectric vibration electric converter W3 of the third embodiment, the same configurations as those of the first embodiment are denoted by the same reference numerals, and descriptions thereof are omitted or simplified.

In addition to the configuration of the first embodiment, the piezoelectric vibration electric converter W3 of the third embodiment has a configuration in which magnets 100, 102, and 102 are attached to the weight 50 and the diaphragm 10 to amplify the vibration of the diaphragm 10. is adopted.
Specifically, as shown in FIG. 5, the piezoelectric vibration electric converter W3 of the third embodiment includes a vibration plate 10 having a piezoelectric element 12 attached to a substantially central portion of a flat plate 11, and an object 1. A base 80 made of a fixed magnetic material, elastic first diaphragm support parts 20, 20 installed on the top surface of the base 80 and supporting both ends of the diaphragm 10, and set on the top surface of the base 80. a solid second diaphragm support portion 30 that supports approximately the central portion of the diaphragm 10; weight support portions 40, 40 attached to the upper surface of the diaphragm 10; and a weight 50 attached to it.
In the third embodiment, the diaphragm 10 is attached to the first diaphragm support parts 20, 20 in a state of overhanging from the first diaphragm support parts 20, 20. As shown in FIG. Specifically, the diaphragm 10 has the upper ends of the first diaphragm support portions 20, 20 attached at positions inside by a predetermined dimension from both ends of the rear surface thereof. Also, the first diaphragm support portions 20 and 20 and the second diaphragm support portion 30 are fixed to the upper surface of the base 80 .

Furthermore, in the third embodiment, "the base 80, the first diaphragm support parts 20, 20, the second diaphragm support part 30, the diaphragm 10, the weight support parts 40, 40, and the weight 50" is covered with a case 82 made of a hollow box-shaped magnetic material.

Magnets 102 and 102 are attached to the lower surface and both ends of the diaphragm 10 in the piezoelectric vibration electric converter W3 of the third embodiment.
Moreover, in the piezoelectric vibration electric converter W3 of the third embodiment, a magnet 100 is attached to the upper surface of the weight 50. As shown in FIG.

According to this configuration, "attractive force due to the magnetic force generated between the magnet 102 attached to the diaphragm 10 and the magnetic substrate 80" and "the magnet 100 attached to the weight 50 and the magnetic case 82 The vibration of the diaphragm 10 can be amplified due to the influence of the "attraction force due to the magnetic force generated between".
Specifically, when a magnetic attractive force acts between the diaphragm 10 and the base 80 , the attractive force increases in accordance with the square of the distance between the diaphragm 10 and the base 80 . Similarly, when a magnetic attractive force acts between the weight 50 and the case 82 , the attractive force increases in accordance with the square of the distance between the weight 50 and the case 82 . Therefore, the diaphragm 10 vibrates more.
Therefore, according to the configuration of the piezoelectric vibration-electricity converter W3 of the third embodiment, vibration can be efficiently converted into an electric signal as compared with that of the first embodiment.

In addition, in the third embodiment shown in FIG. 5, the magnets (102, 102, 100) are attached to the lower surface/both ends of the diaphragm 10 and the upper surface of the weight 50, but it is particularly limited to this. isn't it. The attachment position of the magnet is appropriately designed, and the magnet may be attached to the case 82, for example.
In addition, in the third embodiment, the magnet may be attached to at least one of the diaphragm 10, the weight 50, and the case 82.
In addition, in the third embodiment, the magnet 50 is attached to the upper surface of the diaphragm 10 via the weight support portions 40, 40, but the magnet 50 is not particularly limited to this. For example, as in the above-described second embodiment, separate weights 52, 52 are attached to both ends of the diaphragm 10, respectively, and magnets (not shown) are mounted on the weights 52, 52, respectively. may be attached.

"performance test"
Next, performance tests conducted on the piezoelectric vibration electrical transducer of the present invention will be described.

In this performance test, as an example (with a weight), the piezoelectric vibration electric transducer W1 of the first embodiment of the present invention was attached to a vibration table, and when the vibration table was vibrated, the piezoelectric vibration relative to the vibration acceleration of the vibration table was measured. The output voltage of the element 12 was measured, and the frequency response function of the output voltage of the piezoelectric element 12 with respect to the vibration acceleration of the shaking table was obtained.
In addition, as a comparative example for the embodiment, the vibration of the vibration table when the vibration table 10 with no weight placed thereon is attached to the vibration table only with elastic diaphragm support members at both ends, and the vibration table is vibrated. The output voltage of the piezoelectric element 12 with respect to acceleration was measured, and the frequency response function of the output voltage of the piezoelectric element 12 with respect to the vibration acceleration of the shaking table was obtained. In this comparative example, both ends of the diaphragm 10 without weights are attached to a vibration table via elastic both-ends diaphragm support members.
FIG. 6 is a graph showing the magnitude of the frequency response function of the output voltage of the piezoelectric element 12 with respect to the vibration acceleration of the vibrating table in each of the example and the comparative example.

As shown in the figure, in this test, at a frequency of 100 Hz or less, the vibration level of the example (piezoelectric vibration electric transducer W1 in the state with weight) was approximately "30" compared to the comparative example in the state without weight. ~40 dB” was confirmed.
From the above test results, it can be seen that since the piezoelectric element 12 generates a voltage due to the piezoelectric effect, the generated voltage can be recorded as it is in a data recording device or the like. That is, according to the configuration of the present invention, it is possible to provide inexpensive piezoelectric vibration electric transducers W1, W2, and W3 that can measure and detect vibration without using a dedicated amplifier. Note that the piezoelectric vibration electric transducers W1, W2, and W3 of the present invention do not require power supply unlike MEMS, so a device that does not require a power supply can be provided.

As described above, according to the embodiments (first, second, and third embodiments) of the present invention, the piezoelectric vibration electric converters W1 and W2 do not require an amplifier and a power supply, are inexpensive, and have high durability. , W3 can be provided.

The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the gist of the present invention.

For example, the diaphragm 10 of the above-described embodiments (first, second, and third embodiments) has a configuration in which the piezoelectric element 12 is attached to the upper surface of the flat plate 11, but it is not limited to this configuration. do not have. The vibration plate 10 may have a configuration in which a piezoelectric element 12 is attached to the lower surface of a flat plate 11 .

Moreover, in the piezoelectric vibration electric transducers W1, W2, and W3 of the present invention, the diaphragm 10 and the weight 50 can be attached not only horizontally but also vertically or obliquely.

The piezoelectric vibration electric transducers W1, W2 and W3 of the embodiments (first, second and third embodiments) of the present invention can be used to measure vibrations of devices, moving bodies or structures.
As described above, the piezoelectric vibration electric converters W1, W2, and W3 do not require amplifiers and power supplies, and are inexpensive and highly durable. As a result, when the piezoelectric vibration electric transducers W1, W2 and W3 of the present invention are used for vibration of a device, a moving body or a structure, the cost can be greatly reduced.

Moreover, the piezoelectric vibration electric converters W1, W2, and W3 of the present embodiments (first, second, and third embodiments) can be used for vibration power generation. Floor power generation and the like have already been developed as power generation using piezoelectric elements, but most of the devices up until now have generated power when a person or the like directly steps on the diaphragm.
However, according to the configuration of the piezoelectric vibration electric converters W1, W2, and W3 of the present embodiments (first, second, and third embodiments), the vibrating plate 10 is vibrated by vibrations generated nearby to generate power. can be done. As a result, when the piezoelectric vibration electric converters W1, W2, and W3 of the embodiments (first, second, and third embodiments) of the present invention are used for vibration power generation, it is expected that a larger amount of power generation can be obtained. be done.
For example, the piezoelectric vibration-electric converters W1, W2, and W3 of the present embodiments (first, second, and third embodiments) can It can also be applied to vibration power generation using the vibrations of cars and trains passing by.

1 ... Object

W1, W2, W3 Piezoelectric vibration electric converter 10 Diaphragm 11 Flat plate 12 Piezoelectric element 20 First diaphragm support 30 Second diaphragm support 40 Weight support 50 Weight 52 Weight 70 ... output line 80 ... base 82 ... case 100, 102 ... magnet

Claims (5)

A piezoelectric vibration-to-electricity converter that includes a piezoelectric element and converts the vibration of an object into an electrical signal,
a diaphragm to which the piezoelectric element is attached substantially in the center;
an elastic first diaphragm supporting portion that is installed on the object and supports both ends, the vicinity thereof, or the periphery of the diaphragm;
a second diaphragm supporting portion installed on the object and supporting a substantially central portion of the diaphragm;
a weight attached to the diaphragm;
A piezoelectric vibrating electricity characterized in that strain is generated in the vibration plate by the inertial force of the weight due to the vibration of the object, and the strain generated in the piezoelectric element itself is converted into an electric signal. converter. 2. The piezoelectric vibratory electrical converter of claim 1, wherein said weight is formed in one piece extending across said diaphragm. 2. The piezoelectric vibration-electricity converter according to claim 1, wherein said weights are attached to both ends or a peripheral edge of said diaphragm. A piezoelectric vibration-to-electricity converter that includes a piezoelectric element and converts the vibration of an object into an electrical signal,
a diaphragm to which the piezoelectric element is attached substantially in the center;
a base made of a magnetic material installed on the object;
an elastic first diaphragm supporting portion that is installed on the base and supports both ends, the vicinity thereof, or the periphery of the diaphragm;
a second diaphragm supporting portion installed on the base and supporting a substantially central portion of the diaphragm;
a weight attached to the upper surface of the diaphragm;
The inertial force of the weight caused by the vibration of the object causes the vibration plate to generate strain, and the piezoelectric element converts the strain generated in itself into an electric signal,
The base, the first diaphragm support part, the second diaphragm support part, the diaphragm and the weight are covered with a case formed of a hollow box-shaped magnetic material, and
A piezoelectric vibration-electricity converter, wherein a magnet for amplifying vibration of the diaphragm is attached to at least one of the weight, the diaphragm and the case. A piezoelectric vibration-to-electricity conversion method for converting vibration of an object into an electrical signal using a piezoelectric element,
forming a vibration plate by attaching the piezoelectric element to a substantially central portion of a flat plate;
Through a first elastic diaphragm supporting portion that supports both ends, the vicinity thereof, or the periphery of the diaphragm, and a second diaphragm supporting portion that supports a substantially central portion of the diaphragm, the object is Attach the diaphragm to
Furthermore, a weight is attached to the diaphragm,
A method of converting piezoelectric vibrations to electricity, wherein strain is generated in the vibration plate by inertial force of a weight due to vibration of the object, and the strain generated in the piezoelectric element itself is converted into an electric signal.

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