JP6899210B2 - Insect repellent ultrasonic generator - Google Patents

Description

The present invention relates to an insect repellent ultrasonic generator, and more particularly to an insect repellent ultrasonic generator that repels pests that are harmful to fruit trees and mushrooms.

In recent years, at production sites of fruit trees and mushrooms, it has been required to develop new plant protection technologies such as physical protection technologies that do not depend on chemical pesticides against the feeding damage of pests. Especially at mushroom production sites, it is a serious problem because it cannot be controlled using chemical pesticides.

In response to such problems, as a physical protection technology, by generating an ultrasonic frequency band in which bats, which are considered to be natural enemies of specific pests, are generated, the colonization of pests on fruit trees and mushrooms and the inhibition of spawning are inhibited. Pest control devices have been proposed (see, for example, Patent Document 1). According to this pest control device, a magnetostrictive ferrite type vibrator, a Langevin type vibrator, and a ceramic type vibrator are used as vibration elements for generating ultrasonic waves to control pests.

Japanese Unexamined Patent Publication No. 2013-51925

However, since the vibrating element used in the pest control device of Patent Document 1 uses a hard ferrite-based material or a ceramic-based material, the degree of freedom in shape is limited. Therefore, assuming that ultrasonic waves are output in all directions with respect to an unpredictable approach path of pests, it is necessary to install a plurality of vibrating elements in multiple directions.

Further, when a plurality of vibrating elements are combined to form a sphere, it is expected that the forming process will be extremely complicated.

Further, although ferrite materials and ceramic materials have high ultrasonic output characteristics, the frequency of ultrasonic waves output differs depending on the type of material. Therefore, since it is necessary to design according to the wavelength of the ultrasonic wave generated for each pest to be controlled, the design becomes complicated and has not been widely used.

In addition, when ultrasonic waves are output using a ceramic material, the resonance frequency depends on the thickness of the vibrating element, so the ultrasonic wave generator and amplification device must be adjusted each time according to the frequency of the ultrasonic waves to be output. It became necessary, and it was difficult to instantly generate a frequency in a specific ultrasonic band.

The present invention has been made in view of the above circumstances, and is an unpredictable invasion route of harmful insects by using an organic piezoelectric film having a resonance frequency in the MHz region as an ultrasonic wave generating element. To provide an ultrasonic wave generator for insect control that has a degree of freedom in shape that covers all directions and can output the frequency of the ultrasonic band required instantly by switching to the target individual pest. It is an issue.

That is, the ultrasonic wave generator for insect repellent of the present invention is characterized by the following.

First, the insect-proof ultrasonic generator of the present invention is an insect-proof ultrasonic generator including a power supply device, a signal generator, an amplification device and an ultrasonic generator, and the ultrasonic generator is organic. Electrodes are provided on both sides of the piezoelectric film, and the piezoelectric film is flexible.

Secondly, in the insect repellent ultrasonic generator of the first invention, the organic piezoelectric film contains a polyvinylidene fluoride trifluoroethylene copolymer as a main component and has a thickness in the range of 0.04 to 0.10 mm. Is preferable.

Thirdly, in the insect repellent ultrasonic wave generator of the first or second invention, it is preferable that at least a part of the ultrasonic wave generating element is formed into a curvature in the range of a curvature of 17 to 40 mm.

Fourth, in the insect repellent ultrasonic wave generator of the first to third inventions, the ultrasonic wave generating element can output an ultrasonic wave having a sound pressure of 60 to 120 dB SPL in a wide band region of 20 to 120 kHz. preferable.

Fifth, in the insect repellent ultrasonic wave generators of the first to fourth inventions, it is preferable to use a storage battery to which a solar cell is connected as the power supply device.

According to the present invention, there is a degree of freedom in shape that covers the direction of a wide range of invasion routes of unpredictable pests, and the ultrasonic band that is instantly required for the target individual pest by switching is provided. It is possible to provide an ultrasonic wave generator for insect repellent that can output.

It is a block diagram which shows the structure of the ultrasonic wave generator for insect repellent of this invention. It is a block diagram which shows the structure of the frequency measuring apparatus. It is a graph which shows the frequency characteristic of the organic piezoelectric film used in this invention. It is a photograph showing the flight of Awanomeiga. It is a graph showing the flight trajectory of Awanomeiga, (A) shows the state of movement of individual 1, and (B) shows the state of movement of individual 2. It is a figure showing the sound pressure level when the curvature of the curvature of an ultrasonic wave generating element is changed, (A) shows a curvature of 17mm, (B) shows a curvature of 30mm, and (C) shows a curvature of 40mm.

Hereinafter, the ultrasonic wave generator for insect repellent of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of an ultrasonic wave generator for insect repellent of the present invention.

The insect-proof ultrasonic generator 1 of the present embodiment is at least a signal generator 2 for generating an ultrasonic signal, an amplification device 3 for amplifying an ultrasonic signal generated by the signal generator 2, and an amplification device. It is composed of an ultrasonic generation element 4 that outputs an ultrasonic signal amplified in 3.

The signal generator 2 can be used without particular limitation as long as it is a device capable of generating a generally known ultrasonic signal. For example, the signal generator 2 provided with a vibrating element, a function generator, or software of a personal computer can be used. A signal generator 2 or the like that creates and outputs an ultrasonic waveform can be used.

The wavelength of the ultrasonic signal generated by the signal generator 2 used in the present invention is in the range of 20 to 120 kHz, preferably 30 to 80 kHz, and more preferably 35 to 55 kHz. Of these wavelengths, it is particularly desirable to reliably generate about 35 to 45 kHz, which is the frequency band of ultrasonic waves emitted by bats, which are considered to be natural enemies of pests.

When the ultrasonic signal generated by the signal generator 2 is a digital signal, it is considered that the ultrasonic signal is converted into an analog signal by a D / A (digital / analog) converter and output. The D / A converter may be provided as a function of the signal generator 2, or may be installed between the signal generator 2 and the amplification device 3. Further, the digital signal generated by using the software of the personal computer can be converted into an analog signal by the D / A converter provided in the personal computer and output.

The ultrasonic signal generated by the signal generator 2 is output to the amplification device 3 connected to the signal generator 2.

The amplification device 3 is a device having a so-called power amplifier function in which an ultrasonic signal generated by the signal generation device 2 is input, amplified, and output to the ultrasonic generation element 4. The amplification device 3 can be used without particular limitation as long as it has a function of amplifying the input ultrasonic signal from the ultrasonic generation element 4 so that it can be output at a predetermined sound pressure (dB). For example, a bipolar power supply can be used. , A commonly used audio amplifier for sound, an amplifier circuit using a resonance circuit, or the like can be used.

Among these, a bipolar power source can be preferably used from the viewpoint of wide bandwidth capable of ultrasonic transmission and sound pressure level. In amplification using a bipolar power source, by amplifying the voltage applied to the ultrasonic wave generating element 4, the vibration of the ultrasonic wave generating element 4 itself becomes large, and the sound pressure level can be increased.

The amplification of the ultrasonic signal by the amplification device 3 amplifies the sound pressure of the ultrasonic waves output from the ultrasonic generation element 4 so as to be 60 to 120 dB SPL, preferably 100 to 120 dB SPL, and more preferably 100 to 110 dB SPL. ..

The ultrasonic signal amplified by the amplification device 3 is output from the ultrasonic generation element 4 in the above frequency and sound pressure range.

In the insect repellent ultrasonic generator 1, the signal generator 2 and the amplification device 3 are operated by supplying electricity from an external power supply device, and the power supply uses a generally used AC 100V power supply, a storage battery, or the like. Can be done. Further, when a storage battery is used as the power supply device, the storage battery to which the solar cell is connected can be used to supply electricity stored by sunlight for operation. By using a storage battery to which a solar cell is connected, it is possible to operate the insect repellent ultrasonic generator 1 even in a place where it is difficult to supply electricity from an outdoor AC 100V power supply.

The ultrasonic wave generating element 4 is a flexible film-like piezo element having electrodes attached to both sides of an organic piezoelectric film. As the organic piezoelectric film, for example, a polyvinylidene fluoride trifluoride ethylene copolymer, a polyvinylidene fluoride or the like as a main component can be used. Among these, polyvinylidene fluoride trifluoroethylene copolymer can be particularly preferably used. The thickness of the organic piezoelectric film is not particularly limited, but is usually 0.04 to 0.10 mm, preferably 0.04 to 0.07 mm, and more preferably 0.04 to 0.06 mm. Be done.

As the electrodes attached to both sides of the organic piezoelectric element, any thin film electrode usually used for a film-shaped piezo element can be used without particular limitation, and examples thereof include aluminum foil and copper foil. The thickness of the electrode is not particularly limited, but when the thickness of the entire ultrasonic wave generating element 4 is taken into consideration, about 30 to 300 nm, preferably about 100 to 200 nm is taken into consideration. By setting the thickness of the electrode within the above range, flexibility can be imparted to the ultrasonic wave generating element 4.

The ultrasonic wave generating element 4 using the organic piezoelectric film has excellent flexibility, impact resistance, voltage resistance, water resistance, chemical resistance, etc. as compared with the vibration element using conventional ceramics. The size can also be set as appropriate according to the purpose of measurement.

In particular, since the ultrasonic wave generating element 4 used in the present invention is in the form of a film and has flexibility, it can be easily molded into a desired curvature. The shape of the ultrasonic wave generating element 4 can be appropriately set according to the usage environment and usage conditions, and the shape is not only a flat shape but also a partially bent shape or at least a part of the ultrasonic wave generating element 4 is curved. It can have various shapes such as a shape and a shape wound into a cylindrical shape. The curvature (R) when curved is not particularly limited, but usually, a part of the curvature (R) is in the range of 30 to 400 mm, preferably 60 to 100 mm, and more preferably 17 to 40 mm. Will be considered.

In the ultrasonic wave generator 1 for insect repellent of the present invention, the shape of the ultrasonic wave generating element 4 is formed into various shapes, particularly a part of which is curved, to cover a wide range of directions of invasion routes of unpredictable pests. The ultrasonic wave generator 1 for insect repellent can be provided with a degree of freedom.

In addition, when the relationship between the curvature (R) and the speaker characteristics was investigated by experiments, it was confirmed that reducing the curvature (R) improves the high directivity characteristics, so the curvature should be set appropriately according to the environment in which it is used. Is desirable.

Further, the ultrasonic wave generating element 4 using the specific organic piezoelectric film has a characteristic that it can output a wide band ultrasonic wave because it is very thin as described above and the resonance frequency exists in the MHz region. Unlike the conventional vibrating element using a ceramic material, it is possible to instantly output ultrasonic waves of a required frequency without adjusting the signal generator 2 and the amplification device 3.

The following shows the experimental results of investigating the frequency characteristics of the ultrasonic wave generating element 4 used in the insect repellent ultrasonic wave generator 1 of the present invention.

First, an insect repellent ultrasonic wave generator 1 having a device configuration including a signal generator 2, an amplification device 3, and an ultrasonic wave generator 4 shown in FIG. 1 was prepared. The following devices were used for each device.
Signal generator 2: Creates an ultrasonic waveform using a PC (software: MATLAB). The software outputs a 2ms ultrasonic signal that is frequency-modulated from 135kHz to 5kHz.
Amplifier 3: NF Circuit Design Block's bipolar power supply (NF4010) amplifies the voltage to 40V and outputs it to the ultrasonic generator 4.
Element configuration of ultrasonic wave generating element 4: Film-shaped organic piezoelectric element molded from polyvinylidene fluoride trifluoride copolymer, thickness: 60 μm, size 80 × 80 mm, curvature: almost flat state.

Further, a frequency measuring device 5 having a device configuration including a microphone 6, a preamplifier 7, a main amplifier 8, an A / D converter 9, and a PC 10 shown in FIG. 2 was prepared. The following devices were used for each device.
Microphone 6: 1/8 inch microphone Bruel & Kjaer (B & K4138) + conversion adapter (Bruel & Kjaer UA-0160 (1/8 inch-1 / 4 inch))
Preamplifier 7: Bruel & Kjaer B & K 2670
Main amplifier 8: Bruel & Kjaer B & K2690
A / D converter 9: National Instruments USB-6356
Next, the microphone 6 of the frequency measuring device shown in FIG. 2 is installed at a distance of 40 cm from the front surface of the ultrasonic wave generating element of the ultrasonic wave generator for insect control shown in FIG. 1, and ultrasonic waves of 20 to 120 kHz are generated. Then, the frequency characteristics of the ultrasonic wave generating element were investigated. The result is shown in the frequency-sound pressure level (dB SPL) graph of FIG.

From this result, it was confirmed that the insect repellent ultrasonic wave generator 1 of the present invention can output ultrasonic waves having a sound pressure of 60 to 120 dB SPL in a wide band region of 20 to 120 kHz.

Hereinafter, the ultrasonic wave generator for insect repellent of the present invention will be specifically described with reference to Examples. However, the present invention is not limited to the examples.

As an insect repellent ultrasonic wave generator, an insect repellent ultrasonic wave generator having the same device configuration as the insect repellent ultrasonic wave generator 1 whose frequency characteristics shown in FIG. 1 was investigated was prepared. As the ultrasonic generating element, a film-shaped organic piezoelectric element molded from a polyvinylidene fluoride trifluoroethylene copolymer, having a thickness of 60 μm, a size of 80 × 80 mm, and a curvature (R) of 100 mm was used.

In addition, in order to confirm the insect repellent effect, we used Awanomeiga, which has bats as its natural enemy. This Awanomeiga is a type of moth that is a pest against corn, and like the moths of the noctuid moth such as Spodoptera litura, which is a type of pest against crops such as soybeans, has a repellent reaction by detecting ultrasonic waves in a specific band. Be done. Therefore, the repellent reaction of Awanomeiga to ultrasonic waves can be presumed to be the repellent reaction of Spodoptera litura.

In this embodiment, two Awanomeiga were prepared, and each individual was hung with a thread and randomly arranged in front of an ultrasonic wave generating element having a curvature (R) of 100 mm. Then, the state of the movement of the moth after the ultrasonic wave was output from the ultrasonic wave generating element was photographed from above with a video camera, and the flight trajectory of the Awanomeiga after the ultrasonic wave was output was measured.

As an ultrasonic output condition, a 40 kHz ultrasonic wave having a duration of 0.1 second was repeatedly transmitted at 0.2 second intervals for 10 seconds. Under these conditions, ultrasonic waves were reproduced at intervals of several minutes, and the behavior of Awanomeiga was observed. Experiments were performed 9 times for individual 1 and 6 times for individual 2. Table 1 shows the time required to stop flapping, as opposed to 9 times when individual 1 started flapping ultrasonic waves.

In addition, the state of the 7th individual 1 Awanomeiga in Table 1 was photographed every second. The photograph is shown in FIG. FIG. 5 (A) shows the eighth flight trajectory of the individual 1, and FIG. 5 (B) shows the third flight trajectory of the individual 2. In the graphs of FIGS. 5A and 5B, the vertical axis represents the position (pixels) on the screen, and the horizontal axis represents the time (the start of ultrasonic wave generation is 0).

From the results in Table 1, it was repeatedly confirmed that the flapping of the Awanomeiga was reliably stopped within 10 seconds by using the ultrasonic wave generator for insect repellent according to the present invention. In addition, from FIGS. 4 and 5 (A) and 5 (B), it was observed that one of the two Awanomeiga had a change in the movement showing an escape behavior, and one of them stopped flapping.

From these results, the ultrasonic wave generator for insect repellent of the present invention has a degree of freedom of shape that covers all directions, which is an unpredictable invasion route of pests, and is a changeover switch for an individual target pest. It was confirmed that the ultrasonic wave generator for insect repellent can oscillate the required ultrasonic wave band instantly.

In addition, the relationship between curvature (R: radius) and speaker characteristics was investigated. In the experiment, the curvature (R) of the film-shaped organic piezoelectric element used in the above example was set to 17 mm, 30 mm, and 40 mm, and the sound pressure level was visualized and evaluated by computer analysis.

Visualization by computer analysis was performed using MATLAB under the condition that the distance between the speaker and the microphone was 40 cm.

The signal transmitted from the speaker is measured with a calibrated microphone (Bruel & Kjar, 4138), amplified (Bruel & Kjar, 2670, 2690), AD-converted (National Instruments, USB-6356), and recorded on a PC. did. The recorded signal was frequency-analyzed and the sound pressure level for each frequency was evaluated.

The results are shown in FIGS. 6 (A) to 6 (C). FIG. 6A shows a curvature of 17 mm, FIG. 6B shows a curvature of 30 mm, and FIG. 6C shows a curvature of 40 mm. Further, in FIG. 6, the vertical axis represents the sound pressure and the horizontal axis represents the directivity, and the whiter the color tone, the higher the sound pressure spreads over a wide range. Looking at FIGS. 6A to 6C, R = 30 in (B) is whiter than R = 40 mm in (C), and R = 17 in (A) is whiter than R = 30 in (B). It can be seen that there are many and the sound pressure is high.

From these results, it was confirmed that the smaller the curvature (R), the higher the directivity.

1 Insect-proof ultrasonic generator 2 Signal generator 3 Amplifier 4 Ultrasonic generator 5 Frequency measuring device 6 Microphone 7 Preamplifier 8 Main amplifier 9 A / D converter 10 PC

Claims (4)

An insect repellent ultrasonic generator equipped with a power supply device, a signal generator, an amplification device and an ultrasonic wave generator .
The ultrasonic generating element,
Electrodes are provided on both sides of the organic piezoelectric film ,
Flexible have a,
An ultrasonic wave generator for insect repellent, which is characterized by being molded into a curved shape. The ultrasonic wave generation for insect repellent according to claim 1, wherein the organic piezoelectric film contains a polyvinylidene fluoride trifluoride copolymer as a main component and has a thickness in the range of 0.04 to 0.10 mm. apparatus. The ultrasonic wave generator for insect repellent according to claim 1 or 2 , wherein the ultrasonic wave generating element outputs an ultrasonic wave having a sound pressure of 60 to 120 dB SPL in a wide band region of 20 to 120 kHz. The insect repellent ultrasonic wave generator according to any one of claims 1 to 3 , wherein a storage battery to which a solar cell is connected is used as the power supply device.

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