WO2023053590A1 - Ultrasonic wave-generating device - Google Patents

Ultrasonic wave-generating device Download PDF

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Publication number
WO2023053590A1
WO2023053590A1 PCT/JP2022/023692 JP2022023692W WO2023053590A1 WO 2023053590 A1 WO2023053590 A1 WO 2023053590A1 JP 2022023692 W JP2022023692 W JP 2022023692W WO 2023053590 A1 WO2023053590 A1 WO 2023053590A1
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Prior art keywords
ultrasonic generator
coil
metal foil
pulse current
capacitor
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PCT/JP2022/023692
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French (fr)
Japanese (ja)
Inventor
正人 安達
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株式会社村田製作所
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Publication of WO2023053590A1 publication Critical patent/WO2023053590A1/en

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R23/00—Transducers other than those covered by groups H04R9/00 - H04R21/00
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R3/00—Circuits for transducers, loudspeakers or microphones

Definitions

  • the present invention relates to an ultrasonic generator that has high conversion efficiency and is capable of varying the frequency of generated ultrasonic waves.
  • Ultrasonic generators are widely used for distance detection.
  • a certain type of ultrasonic generator also serves as an ultrasonic detector, transmits ultrasonic waves toward an object, receives the ultrasonic waves that are reflected back from the object, and receives the ultrasonic waves from transmission to reception. Detect the distance to the object by the length of time.
  • Another ultrasonic wave generator is used in combination with an ultrasonic detector, transmits ultrasonic waves, receives the ultrasonic waves with the ultrasonic detector, and determines the length of time from transmission to reception. Detects the distance to the sonic detector.
  • Patent Document 1 Japanese Utility Model Publication No. 4-27280 discloses a conventional ultrasonic generator (ultrasonic transmitter/receiver).
  • the ultrasonic generator disclosed in Patent Document 1 has a structure in which an additional resonator (horn) is attached to a unimorph transducer in which a piezoelectric plate and a metal disc are bonded together.
  • ultrasonic waves are transmitted from the additional resonator by driving the unimorph transducer.
  • the ultrasonic generator of Patent Document 1 Because the ultrasonic generator of Patent Document 1 has a high Qm value (mechanical quality factor), it generates ultrasonic waves with high efficiency at a specific driving frequency. When the driving frequency is changed, the ultrasonic generator of Patent Literature 1 is considered to be used at a specific driving frequency to generate ultrasonic waves of a specific frequency, because it is thought that the conversion efficiency drops sharply. Therefore, the ultrasonic generator of Patent Document 1 has a problem that interference occurs when a plurality of devices are used in close proximity at the same time.
  • Qm value mechanical quality factor
  • Non-Patent Document 1 (“Overview of Airborne Ultrasonic Transducer”) discloses an ultrasonic generator that solves this problem and allows the frequency of the ultrasonic waves to be generated to be variable.
  • the ultrasonic generator disclosed in Non-Patent Document 1 is called a thermophone, and has a structure in which a metal film is provided on a heat-dissipating substrate with a thin heat-insulating layer interposed therebetween.
  • the ultrasonic generator of Non-Patent Document 1 when an electric current is applied to the metal film, the metal film generates heat, and the air in contact with the metal film is warmed to generate ultrasonic waves.
  • the ultrasonic generator of Non-Patent Document 1 can change the frequency of the ultrasonic waves to be generated by changing the frequency of the current applied to the metal film.
  • the ultrasonic generator of Non-Patent Document 1 converts energy in the order of electricity, heat, and ultrasonic waves, there are problems of large loss and low conversion efficiency, and it is difficult to obtain ultrasonic waves with a large sound pressure. There was a problem.
  • Patent Document 2 Japanese Unexamined Patent Application Publication No. 7-328539 discloses another ultrasonic wave generator (electromagnetic acoustic transducer).
  • the ultrasonic generator disclosed in Patent Document 2 generates ultrasonic waves by electromagnetic repulsion.
  • the ultrasonic wave generator of Patent Document 2 is disclosed in FIG. 5 of Patent Document 2 and the like as conventional technology.
  • FIG. 11 of the present application shows an ultrasonic generator 1000 of Patent Document 2. As shown in FIG.
  • the ultrasonic generator 1000 of Patent Document 2 includes a spiral coil 50, a disk-shaped conductive vibration radiator 52 arranged at a certain distance from the spiral coil 50, and a pulse current applied to the spiral coil 50. is provided with a pulse generator 51 for supplying The pulse generator 51 is composed of a DC power supply 511 , a capacitor 512 and a switch 513 .
  • the changeover switch 513 can switch the destination to which the capacitor 512 is connected to either the DC power supply 511 or the spiral coil 50 .
  • the ultrasonic generator 1000 of Patent Document 2 first switches the selector switch 513 to the DC power supply 511 side, and accumulates power supplied from the DC power supply 511 in the capacitor 512 . Next, the selector switch 513 is switched to the spiral coil 50 side, and a large current is instantaneously supplied from the capacitor 512 to the spiral coil 50 .
  • the current When a large current is momentarily supplied from the capacitor 512 to the spiral coil 50 , the current generates a magnetic field due to electromagnetic induction in the direction from the spiral coil 50 to the conductive vibration radiator 52 .
  • the magnetic field induces an eddy current in the conductive vibration radiator 52 , and the eddy current generates a magnetic field by electromagnetic induction in the direction from the conductive vibration radiator 52 to the spiral coil 50 .
  • the ultrasonic generator 1000 of Patent Document 2 can change the frequency of the generated ultrasonic waves by changing the energization time of the current supplied from the capacitor 512 to the spiral coil 50 .
  • the ultrasonic generator of Patent Document 2 is considered to be used for a specific energizing time and generate ultrasonic waves of a specific frequency, because it is thought that the conversion efficiency drops sharply when the energizing time is changed.
  • the ultrasonic generator 1000 of Patent Document 2 is described in paragraph [0004] of Patent Document 2 as follows: "As described above, the conventional electromagnetic acoustic transducer that excites the disk-shaped vibration radiator 52 6(a) and bending vibration shown in FIG. 6(b) are simultaneously excited, and bending-extension vibration combining the two, that is, vibration due to Poisson coupling, is obtained.” , the conductive vibration radiator 52 is made of a metal plate having a certain thickness.
  • the conductive vibration radiator 52 is preferably thin and light. This is because if the conductive vibration radiator 52 is thick and heavy, the initial speed will be slow.
  • the ultrasonic generator 1000 of Patent Document 2 has a problem that the conversion efficiency is low because the conductive vibration radiator 52 is made of a metal plate having a large thickness.
  • Patent Document 2 the application invention of Patent Document 2 (the invention disclosed in FIG. 1 of Patent Document 2, etc.) has a conductive vibration radiator formed into a hemispherical shell shape (bowl shape) while maintaining its shape.
  • a conductive vibration radiator formed into a hemispherical shell shape (bowl shape) while maintaining its shape.
  • An attempt is being made to improve the conversion efficiency by reducing the thickness and weight of the vibration radiator.
  • the conductive vibration radiator is made into a hemispherical shell shape, the central part of the hemisphere is close to the spiral coil, so a large repulsive force can be obtained, but the peripheral part of the hemisphere is far from the spiral coil, so a large repulsive force can be obtained. Therefore, it is considered that the invention of Patent Document 2 does not improve the conversion efficiency so much as a whole.
  • the ultrasonic generator 1000 of Patent Document 2 has the problem that the conversion efficiency is low because the conductive vibration radiator 52 is made of a thick metal plate. Further, in the ultrasonic generator 1000 of Patent Document 2, the conductive vibration radiator 52 is made of a metal plate having a large thickness. Therefore, it has been difficult to widen the area from which ultrasonic waves are radiated.
  • a coil a metal foil placed on at least one side of the first main surface and the second main surface under tension, and a pulse current generating circuit for applying a pulse current to the coil.
  • the ultrasonic generator according to one embodiment of the present invention uses a tensioned metal foil as a medium for generating an eddy current and a repelling magnetic field, so the conversion efficiency is extremely high. That is, the ultrasonic generator according to one embodiment of the present invention uses a thin and light metal foil as a medium, so the conversion efficiency is extremely high. Further, in the ultrasonic generator according to one embodiment of the present invention, since the metal foil is used as the vibration radiator for generating the ultrasonic waves, the area of the main surface of the metal foil is increased to radiate the ultrasonic waves. It is easy to widen the area. Further, the ultrasonic generator according to one embodiment of the present invention can change the frequency of the generated ultrasonic waves by changing the duration of the pulse current applied to the coil.
  • FIG. 1A is a front view of the ultrasonic generator 100 according to the first embodiment.
  • FIG. 1B is a plan view of the ultrasonic generator 100.
  • FIG. 2A and 2B are cross-sectional views of the ultrasonic generator 100, respectively.
  • FIG. 3A is an explanatory diagram of the ultrasonic generator 100 viewed from the front.
  • FIG. 3B is an explanatory diagram of the ultrasonic generator 100 viewed from the plane.
  • 4A and 4B are cross-sectional views of the ultrasonic generator 200 according to the second embodiment, respectively.
  • FIG. 5 is a cross-sectional view of an ultrasonic generator 300 according to the third embodiment.
  • FIG. 6A is an explanatory diagram of an ultrasonic generator 400 according to the fourth embodiment.
  • FIG. 6B is a graph showing the characteristics of the ultrasonic waves generated by the ultrasonic generator 400.
  • FIG. 7A is an explanatory diagram of an ultrasonic generator 500 according to the fifth embodiment.
  • FIG. 7B is a graph showing characteristics of ultrasonic waves generated by the ultrasonic generator 500.
  • FIG. 8 is a graph showing characteristics of ultrasonic waves generated by each ultrasonic generator according to the sixth embodiment.
  • FIG. 9 is an explanatory diagram of an ultrasonic generator 700 according to the seventh embodiment.
  • FIG. 10 is an exploded perspective view of essential parts of an ultrasonic generator 800 according to the eighth embodiment.
  • FIG. 11 is an explanatory diagram of a conventional ultrasonic generator 1000. As shown in FIG.
  • each embodiment exemplifies the embodiment of the present invention, and the present invention is not limited to the content of the embodiment. Moreover, it is also possible to combine the contents described in different embodiments, and the contents of the implementation in that case are also included in the present invention.
  • the drawings are intended to aid understanding of the specification, and may be schematically drawn, and the drawn components or the dimensional ratios between the components may not be the same as those described in the specification. The proportions of those dimensions may not match.
  • constituent elements described in the specification are omitted in the drawings, or where the number of constituent elements is omitted.
  • FIG. 1A is a front view of the ultrasonic generator 100.
  • FIG. 1B is a plan view of the ultrasonic generator 100.
  • FIG. 2A and 2B are cross-sectional views of the ultrasonic generator 100, respectively.
  • FIG. 3A is an explanatory diagram of the ultrasonic generator 100 viewed from the front.
  • FIG. 3B is an explanatory diagram of the ultrasonic generator 100 viewed from the plane. Note that FIG. 2(A) shows the dashed-dotted line YY portion of FIG. 2(B), and FIG. 2(B) shows the dashed-dotted line XX portion of FIG. 2(A). 1A, 1B, 2A and 2B, illustration of the pulse current generating circuit 4 is omitted.
  • the ultrasonic generator 100 includes a frame 1.
  • the frame 1 has a hollow portion 1a and a pair of outlet holes 1b and 1c.
  • the lead-out holes 1b and 1c are for leading out a pair of ends 2c and 2d of the coil 2, which will be described later, to the outside.
  • the material of the frame 1 is arbitrary, for example, resin, ceramic, metal, wood, glass, etc. can be used.
  • the shape of the frame 1 is arbitrary, but in this embodiment, it is rectangular when viewed from the plane direction.
  • the frame 1 is not an essential component, and other structures may be used or omitted.
  • the ultrasonic generator 100 includes a coil 2.
  • the coil 2 may be of any material, shape, etc., but in the present embodiment, a copper wire, which is a conductive wire with an insulating coating (not shown) formed on the outer surface, is spirally wound into a single layer. used.
  • the coil 2 has a first main surface 2a and a second main surface 2b facing each other.
  • the coil 2 has a pair of ends 2c, 2d.
  • the material and diameter of the conductor wire of the coil 2 are arbitrary, and instead of the copper wire, Ag wire, Ni wire, Al wire, Mg wire, W wire, Mo wire, Au wire, nickel-chromium alloy wire, etc. may be used. may be used. Any material can be used for the insulating coating formed on the outer surface of the conductor, and for example, enamel can be used. In the present invention, the insulating coating on the outer surface of the conductor wire of the coil 2 is not an essential component, and can be omitted. Also, instead of the coil 2 wound with conductive wire, a coil made of patterned electrodes or the like printed on a substrate or the like may be used. In this case, the insulating coating may or may not be formed on the pattern electrodes.
  • the coil 2 is accommodated in the hollow portion 1a of the frame 1. An end portion 2c of the coil 2 is led out from the lead-out hole 1b of the frame 1, and an end portion 2d of the coil 2 is led out from the lead-out hole 1c of the frame 1 to the outside.
  • the ultrasonic wave generator 100 is equipped with one sheet of metal foil 3 .
  • the metal foil 3 may be made of any material, but preferably has high electrical conductivity, is light in weight, has high strength, and is inexpensive.
  • aluminum foil, SUS foil, copper foil, nickel foil, iron foil, etc. can be used.
  • SUS foil When aluminum foil is used, it is possible to obtain a metal foil 3 with high electrical conductivity, light weight, and low cost.
  • SUS foil a metal foil 3 with high strength can be obtained.
  • the thickness of the metal foil 3 is preferably 3 ⁇ m or more and 100 ⁇ m or less in the case of aluminum foil, for example. This is because if the thickness of the metal foil 3 is less than 3 ⁇ m, the strength of the metal foil 3 may be insufficient. This is because if the thickness of the metal foil 3 exceeds 100 ⁇ m, the conversion efficiency of the ultrasonic wave generator 100 may be lowered, or it may become impossible to generate ultrasonic waves with a large sound pressure. Note that the thickness of the metal foil 3 will be discussed later in the sixth embodiment.
  • At least a part of the outer periphery of the metal foil 3 is fixed to the frame 1 under tension.
  • the metal foil 3 closes the opening on one side of the hollow portion 1a of the frame 1 (the side of the first main surface 2a of the coil 2), and extends to the opposite side via the side surface of the frame 1. It turns around and closes the opening on the other side of the hollow portion 1a of the frame 1 (on the side of the second main surface 2b of the coil 2).
  • Any method can be used to fix the metal foil 3 to the frame 1.
  • the metal foil 3 can be fixed with an adhesive.
  • the frame 1 is not an essential component in the present invention, and other structures may be used or omitted.
  • the ultrasonic generator 100 of this embodiment has a structure in which the openings on both sides of the hollow portion 1a of the frame 1 are closed with one sheet of metal foil 3, it is easy to manufacture and has high productivity. .
  • the metal foil that closes the opening on one side of the hollow portion 1a of the frame 1 and the metal foil that closes the opening on the other side of the hollow portion 1a of the frame 1 Two foils may be separately prepared and the openings may be closed separately.
  • a gap S is provided between the first main surface 2a of the coil 2 and the metal foil 3 and between the second main surface 2b of the coil 2 and the metal foil 3. formed.
  • the spiral portion and the portion extending from the spiral portion to the one end 2c inevitably intersect, and these gaps S are formed to enable this intersection. is.
  • these gaps S may be omitted and the coil 2 and the metal foil 3 may be brought into contact with each other.
  • the ultrasonic generator 100 includes a pulse current generating circuit 4, as shown in FIGS. 3(A) and 3(B).
  • the pulse current generating circuit 4 has a pair of output terminals 4a and 4b, as shown in FIG. 3(B). Output terminal 4 a is connected to one end 2 c of coil 2 , and output terminal 4 b is connected to the other end 2 d of coil 2 .
  • the pulse current generation circuit 4 further includes a DC power supply 4c, a capacitor 4d, and a switch 4e, as shown in FIG. 3(B).
  • the type of the capacitor 4d is arbitrary, but for example, a laminated ceramic capacitor, a film capacitor, an electrolytic capacitor, etc. can be used. However, if a laminated ceramic capacitor or a film capacitor is used, the equivalent series resistance (ESR) is low. Therefore, it is preferable.
  • ESR equivalent series resistance
  • the output terminal 4a of the pulse current generation circuit 4 is connected to one switching terminal of the changeover switch 4e.
  • the other switching terminal of the changeover switch 4e is connected to the positive side terminal of the DC power supply 4c.
  • a fixed terminal of the switch 4e is connected to one terminal of the capacitor 4d.
  • the negative side terminal of the DC power supply 4c and the other terminal of the capacitor 4d are each connected to the output terminal 4b.
  • the pulse current generation circuit 4 can switch the destination to which the capacitor 4d is connected to either the DC power supply 4c or the coil 2 by switching the selector switch 4e.
  • the selector switch 4e is switched to the DC power supply 4c side, and the power supplied from the DC power supply 4c is stored in the capacitor 4d.
  • the selector switch 4e is switched to the coil 2 side, and a large current is instantaneously supplied to the coil 2 from the capacitor 4d. That is, the capacitor 4d is discharged.
  • the current causes the coil 2 to move in the direction of the metal foils 3 arranged on both sides of the first main surface 2a and the second main surface 2b of the coil 2.
  • Each generates a magnetic field due to electromagnetic induction.
  • the magnetic field generated by the coil 2 induces eddy currents in the metal foil 3 on the first main surface 2a side and the metal foil 3 on the second main surface 2b side.
  • Due to the eddy current generated in the metal foil 3 a magnetic field due to electromagnetic induction is generated in the direction of the coil 2 from the metal foil 3 on the first main surface 2a side and the metal foil 3 on the second main surface 2b side. Occur.
  • the ultrasonic generator 100 can generate pulsed ultrasonic waves by repeating the above operation at a predetermined cycle.
  • the ultrasonic generator 100 discharges all the accumulated electric charges
  • the conduction time of the pulse current applied from the capacitor 4d to the coil 2 is changed. , can change the frequency of the generated ultrasound.
  • the amount of charge stored in the capacitor 4d can be changed by changing the voltage of the DC power supply 4c that supplies power to the capacitor 4d or by changing the capacity of the capacitor 4d.
  • the voltage of the DC power supply 4c that supplies power to the capacitor 4d may be changed, and the capacity of the capacitor 4d may be changed. Details will be described later in a fourth embodiment and a fifth embodiment.
  • the pulse current generation circuit 74 is provided with a semiconductor switching element 74e in place of the changeover switch 4e.
  • the energization time (discharge time) of the pulse current applied to the coil 2 may be changed. Also in this case, the frequency of the generated ultrasonic waves can be changed.
  • the ultrasonic generator 100 of the first embodiment uses the metal foil 3 under tension as the medium that generates eddy currents and repulsive magnetic fields. Vibration-free, single-mode, and extremely high conversion efficiency. Further, according to the ultrasonic generator 100, it is possible to generate an ultrasonic wave having a single frequency and a good waveform. The fact that the generated ultrasonic waves are of a single frequency also contributes to the improvement of the conversion efficiency. Further, the ultrasonic wave generator 100 can change the frequency of the generated ultrasonic waves by changing the charge amount accumulated in the capacitor 4 d of the pulse current generating circuit 4 . Moreover, by increasing the area of the main surface of the metal foil 3, the ultrasonic generator 100 can easily widen the area from which the ultrasonic waves are radiated.
  • FIGS. 4A and 4B respectively show an ultrasonic generator 200 according to the second embodiment.
  • 4A and 4B are cross-sectional views of the ultrasonic generator 200, respectively.
  • FIG. 4(A) shows the dashed-dotted line YY portion of FIG. 4(B)
  • FIG. 4(B) shows the dashed-dotted line XX portion of FIG. 4(A).
  • illustration of the pulse current generating circuit 4 is omitted.
  • the ultrasonic generator 200 of the second embodiment has partially changed the configuration of the ultrasonic generator 100 of the first embodiment.
  • the thickness of the frame 21 is made smaller than the thickness of the frame 1 of the ultrasonic generator 100 .
  • the thickness of the frame 21 is the same as the diameter of the conductive wire (copper wire) of the coil 2 .
  • the thickness of the hollow portion 21a of the frame 21 is also reduced.
  • the frame 21 of the ultrasonic wave generator 200 is provided with lead-out holes 21b and 21c like the lead-out holes 1b and 1c of the ultrasonic wave generator 100 .
  • each wire in Z was scaled to 50% of the thickness of the wires in the other regions, respectively.
  • each conductive wire is rolled in the region Z to have a thickness of 50% of the thickness of the conductive wire in the other regions.
  • the total thickness of the two conductors vertically intersecting in the region Z is equal to the thickness of the conductors in the other regions.
  • the coil 2 is in contact with the metal foil 3 on both sides of the first main surface 2a and the second main surface 2b.
  • the ultrasonic generator 200 of the second embodiment since the coil 2 is in close proximity (contact) with the metal foil 3 on both sides of the first main surface 2a and the second main surface 2b, the ultrasonic wave generated from the coil 2 The magnetic field generated by the metal foil 3 and the magnetic field generated by the metal foil 3 repel each other with a greater force than the ultrasonic generator 100 of the first embodiment. Therefore, the ultrasonic generator 200 has a higher conversion efficiency than the ultrasonic generator 100 . In addition, the ultrasonic wave generator 200 generates a higher sound pressure of ultrasonic waves than the ultrasonic wave generator 100 does.
  • FIG. 5 shows an ultrasonic generator 300 according to the third embodiment.
  • FIG. 5 is a cross-sectional view of the ultrasonic generator 300 . 5, illustration of the pulse current generating circuit 4 is omitted.
  • the ultrasonic generator 300 of the third embodiment is the ultrasonic generator 100 of the first embodiment fixed to a newly provided pedestal 35 . Specifically, one main surface (first main surface 2 a ) of the ultrasonic generator 100 was fixed to the base 35 .
  • the material of the pedestal 35 is arbitrary, but for example, resin, ceramic, metal, or the like can be used. Also, the method of fixing the ultrasonic generator 100 to the base 35 is arbitrary. A method such as bonding with an adhesive can be used.
  • the ultrasonic generator 300 when a large current is instantaneously supplied from the capacitor 4d to the coil 2, the magnetic field generated from the coil 2, the magnetic field generated from the metal foil 3 on the first main surface 2a side of the coil 2, and The magnetic field generated from the metal foil 3 on the second main surface 2b side of the coil 2 repels each other.
  • the metal foil 3 on the first main surface 2a side of the coil 2 is fixed to the base 35, only the metal foil 3 on the second main surface 2b side of the coil 2 is separated from the coil 2. move away. As a result, air is pushed out by the metal foil 3 on the side of the second main surface 2b of the coil 2, and ultrasonic waves are generated.
  • the ultrasonic generator 300 of the third embodiment only the metal foil 3 on the second main surface 2b side of the coil 2 moves, so compared to the ultrasonic generator 100, a larger repulsive force can be generated. Ultrasonic waves with a higher sound pressure can be generated. Theoretically, the ultrasonic generator 300 can generate ultrasonic waves with twice the sound pressure of the ultrasonic generator 100 .
  • FIG. 6A shows an ultrasonic generator 400 according to the fourth embodiment.
  • FIG. 6A is an explanatory diagram of the ultrasonic generator 400.
  • FIG. 6A is an explanatory diagram of the ultrasonic generator 400.
  • the ultrasonic generator 400 of the fourth embodiment has partially changed the configuration of the ultrasonic generator 100 of the first embodiment.
  • the DC power supply 4c of the pulse current generating circuit 4 was a fixed voltage power supply, but the ultrasonic generator 400 changes this to a DC power supply of the pulse current generating circuit 44.
  • 44c used a voltage variable power supply.
  • the DC power supply 44c can switch the voltage to be supplied to 30V, 50V, 75V, and 100V, for example.
  • the capacitance of the capacitor 4d of the pulse current generating circuit 4 was set to 22 ⁇ F.
  • the ultrasonic generator 400 changes the amount of charge accumulated in the capacitor 4d, so that the frequency of the generated ultrasonic waves can be changed.
  • FIG. 6(B) shows the waveforms of ultrasonic waves generated when the voltage supplied by the DC power supply 44c is switched to 30V, 50V, 75V, and 100V.
  • the Y-axis indicates the output voltage of the ultrasonic detection device (microphone) that detected the generated ultrasonic waves.
  • the ultrasonic wave generator 400 can change the frequency of the generated ultrasonic waves by changing the voltage of the DC power supply 44c. Specifically, as the voltage (charging voltage) supplied to the capacitor 4d increases, the sound pressure of the ultrasonic waves increases and the frequency of the ultrasonic waves decreases.
  • FIG. 7A shows an ultrasonic generator 500 according to the fifth embodiment.
  • FIG. 7A is an explanatory diagram of the ultrasonic generator 500 .
  • the ultrasonic generator 500 of the fifth embodiment has partially changed the configuration of the ultrasonic generator 100 of the first embodiment.
  • the capacitor 4d of the pulse current generating circuit 4 is a fixed capacitor, but in the ultrasonic generator 500, this is changed so that the capacitor 54d of the pulse current generating circuit 54 is A variable capacitor was used.
  • Capacitor (variable capacitor) 54d can switch the capacitance to, for example, 2.2 ⁇ F, 22 ⁇ F, and 220 ⁇ F.
  • the voltage of the power supplied to the capacitor 54d by the DC power supply 4c of the pulse current generating circuit 4 was set to 100V.
  • the ultrasonic generator 500 changes the amount of charge accumulated in the capacitor 54d, so that the frequency of the generated ultrasonic waves can be changed.
  • FIG. 7(B) shows the waveforms of ultrasonic waves generated when the capacitance of the capacitor 54d is switched to 2.2 ⁇ F, 22 ⁇ F, and 220 ⁇ F.
  • the ultrasonic wave generator 500 can change the frequency of the generated ultrasonic waves by changing the capacitance of the capacitor 54d. Specifically, as the capacitance of the capacitor 54d is increased, the frequency of the ultrasonic wave is decreased.
  • the ultrasonic generator 100 of the first embodiment shown in FIGS. 1A, 1B, 2A, 2B, 3A, and 3B In terms of structure, four ultrasonic generators (not shown) were manufactured by changing the thickness of the metal foil 3 to 10 ⁇ m, 30 ⁇ m, 50 ⁇ m, and 100 ⁇ m. Aluminum foil was used for each of the metal foils 3 .
  • FIG. 8 shows the waveform of ultrasonic waves generated from each ultrasonic generator. As can be seen from FIG. 8, as the thickness of the metal foil 3 increases, the sound pressure decreases and the frequency decreases. Considering the conversion efficiency, it is preferable that the thickness of the metal foil 3 is thin.
  • FIG. 9 shows an ultrasonic generator 700 according to the seventh embodiment. However, FIG. 9 is an explanatory diagram of the ultrasonic generator 700 .
  • the ultrasonic generator 700 of the seventh embodiment has partially changed the configuration of the ultrasonic generator 100 of the first embodiment.
  • the pulse current generating circuit 4 includes the changeover switch 4e, but in the ultrasonic generator 700, the changeover switch 4e is omitted, and a semiconductor switching element 74e is provided instead.
  • a general transistor is used as the semiconductor switching element 74e, but the type of the semiconductor switching element 74e is arbitrary, and for example, an FET (Field Effect Transistor) or the like may be used.
  • the ultrasonic generator 700 can change the energization time (discharge time) of the pulse current applied from the capacitor 4d to the coil 2, thereby changing the frequency of the ultrasonic waves to be generated. can be done.
  • FIG. 10 shows an ultrasonic generator 800 according to the eighth embodiment.
  • FIG. 8 is an exploded perspective view of the main part of the ultrasonic generator 800.
  • FIG. 10 shows an ultrasonic generator 800 according to the eighth embodiment.
  • FIG. 8 is an exploded perspective view of the main part of the ultrasonic generator 800.
  • the ultrasonic generator 800 of the eighth embodiment has partially changed the configuration of the ultrasonic generator 100 of the first embodiment.
  • the ultrasonic generator 100 uses the coil 2 spirally wound in a single layer.
  • a coil 82 commonly referred to as an alpha winding, was used.
  • the coil 82 of this embodiment is composed of two layers, a lower layer 82a and an upper layer 82b. Although the lower layer 82a and the upper layer 82b are depicted in FIG. 10 in a separated state, the lower layer 82a and the upper layer 82b are actually in contact or close to each other.
  • the coil 82 causes the metal foil 3 to generate a magnetic field by electromagnetic induction.
  • the conductor wire of the coil 82 has a flat cross section, but the conductor wire of the coil 82 may have a circular cross section as in the other embodiments.
  • a conductive wire having a flat cross section like the coil 82 may be used as the coil 2 of another embodiment.
  • the coil 2 is formed by winding a conductor wire in a single layer, but instead of this, a conductor wire wound in multiple layers may be used. Also, the insulating coating of the coil 2 may be omitted if there is a gap between the coil 2 and the metal foil 3 .
  • the coil 2 is formed by spirally winding a conductive wire, but the coil is not limited to this form. may be used.
  • the shape of the metal foil 3 is rectangular when viewed in the planar direction, but the shape of the metal foil 3 is arbitrary, and may be circular instead of rectangular, for example.
  • the ultrasonic generator according to one embodiment of the present invention is as described in the "Means for Solving the Problems" column.
  • ultrasonic generator it is also preferred that metal foils are arranged on both sides of the first main surface and the second main surface of the coil, respectively. In this case, ultrasonic waves can be generated on both sides of the ultrasonic generator.
  • the metal foil arranged on the side of the first main surface and the metal foil arranged on the side of the second main surface wrap the coil from both sides of the first main surface and the second main surface. It is also preferable that In this case, fabrication of the ultrasonic generator is facilitated, and productivity is improved.
  • a frame having a hollow portion is provided, the coil is housed in the hollow portion of the frame, and the metal foil is fixed to the frame with at least a part of the outer circumference being under tension.
  • the conversion efficiency of the ultrasonic generator increases.
  • the ultrasonic generator can be manufactured easily, and the productivity is improved.
  • the coil is coated with insulation and that the coil and the metal foil are in contact.
  • the magnetic field generated by the coil and the magnetic field generated by the metal foil repel each other with great force. Therefore, the conversion efficiency of the ultrasonic generator is increased.
  • the metal foil is an aluminum foil. In this case, a metal foil with high electrical conductivity, light weight, and low cost can be obtained.
  • the thickness of the metal foil is preferably 3 ⁇ m or more and 100 ⁇ m or less when the metal foil is aluminum foil, for example. This is because if the thickness is less than 3 ⁇ m, the strength of the metal foil may be insufficient. This is because if the thickness exceeds 100 ⁇ m, there is a risk that the conversion efficiency will decrease, or that it will be impossible to generate ultrasonic waves with a large sound pressure.
  • the coil may be a conductor wound in a spiral in a single layer.
  • the coil may be a conductive wire wound in multiple layers spirally.
  • the pulse current generating circuit includes a power supply, a capacitor, and a changeover switch.
  • a pulse current can be supplied to the coil with a simple configuration.
  • the amount of electric charge stored in the capacitor is variable, and the energization time of the pulse current applied to the coil from the pulse current generation circuit is also variable.
  • the frequency of ultrasonic waves generated by the ultrasonic generator can be made variable.
  • the amount of charge stored in the capacitor is variable, and the energization time of the pulse current applied to the coil from the pulse current generation circuit is also variable.
  • the frequency of ultrasonic waves generated by the ultrasonic generator can be made variable.
  • the pulse current generation circuit includes a power supply, a capacitor, and a semiconductor switching element, and that the semiconductor switching element is controlled so that the energization time of the pulse current applied from the pulse current generation circuit to the coil is variable.
  • the frequency of ultrasonic waves generated by the ultrasonic generator can be made variable.

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Abstract

Provided is an ultrasonic wave-generating device that has high conversion efficiency.　The ultrasonic wave-generating device comprises: a coil 2 that includes a first main surface 2a and a second main surface 2b which are on opposite front/back sides; a metal foil 3 that is disposed in a state in which tension is applied thereto, on the first main surface 2a side and/or the second main surface 2b side; and a pulsed current generation circuit 4 that applies a pulsed current to the coil 2.

Description

超音波発生装置ultrasonic generator
　本発明は、変換効率が高く、かつ、発生させる超音波の周波数を可変とすることが可能な、超音波発生装置に関する。 The present invention relates to an ultrasonic generator that has high conversion efficiency and is capable of varying the frequency of generated ultrasonic waves.
　距離検知に、超音波発生装置が広く利用されている。たとえば、ある種の超音波発生装置は、超音波検知装置を兼ね、目的物に向って超音波を送信し、目的物に反射して戻ってきた超音波を自ら受信し、送信から受信までの時間の長さで、目的物までの距離を検知する。また、別の超音波発生装置は、超音波検知装置とセットで使用され、超音波を送信し、その超音波を超音波検知装置で受信し、送信から受信までの時間の長さで、超音波検知装置までの距離を検知する。 Ultrasonic generators are widely used for distance detection. For example, a certain type of ultrasonic generator also serves as an ultrasonic detector, transmits ultrasonic waves toward an object, receives the ultrasonic waves that are reflected back from the object, and receives the ultrasonic waves from transmission to reception. Detect the distance to the object by the length of time. Another ultrasonic wave generator is used in combination with an ultrasonic detector, transmits ultrasonic waves, receives the ultrasonic waves with the ultrasonic detector, and determines the length of time from transmission to reception. Detects the distance to the sonic detector.
　特許文献１（実公平４－２７２８０公報）に、従来の超音波発生装置（超音波送受波器）が開示されている。特許文献１の超音波発生装置は、圧電板と金属円板が貼り合わされたユニモルフ振動子に、付加共振子（ホーン）を取り付けた構造からなる。特許文献１の超音波発生装置は、ユニモルフ振動子を駆動させることにより、付加共振子から超音波が送信される。 Patent Document 1 (Japanese Utility Model Publication No. 4-27280) discloses a conventional ultrasonic generator (ultrasonic transmitter/receiver). The ultrasonic generator disclosed in Patent Document 1 has a structure in which an additional resonator (horn) is attached to a unimorph transducer in which a piezoelectric plate and a metal disc are bonded together. In the ultrasonic generator disclosed in Patent Document 1, ultrasonic waves are transmitted from the additional resonator by driving the unimorph transducer.
　特許文献１の超音波発生装置は、Ｑｍ値（機械的品質係数）が高いため、特定の駆動周波数において、高い効率で超音波を発生させる。特許文献１の超音波発生装置は、駆動周波数を変えると、変換効率が急激に低下すると考えられるため、特定の駆動周波数で使用され、特定の周波数の超音波を発生させると考えられる。したがって、特許文献１の超音波発生装置は、複数の装置を近接して同時に使用した場合に、混信が発生するという問題があった。 Because the ultrasonic generator of Patent Document 1 has a high Qm value (mechanical quality factor), it generates ultrasonic waves with high efficiency at a specific driving frequency. When the driving frequency is changed, the ultrasonic generator of Patent Literature 1 is considered to be used at a specific driving frequency to generate ultrasonic waves of a specific frequency, because it is thought that the conversion efficiency drops sharply. Therefore, the ultrasonic generator of Patent Document 1 has a problem that interference occurs when a plurality of devices are used in close proximity at the same time.
　この問題を解決し、発生させる超音波の周波数を可変とした超音波発生装置が、非特許文献１（「空中超音波トランスデューサの概要」）に開示されている。非特許文献１の超音波発生装置は、サーモフォンと呼ばれ、放熱基板の上に薄い断熱層を挟んで金属膜を設けた構造からなる。非特許文献１の超音波発生装置は、金属膜に電流を流すと、金属膜が発熱し、金属膜に接する空気が温められて超音波が発生する。 Non-Patent Document 1 ("Overview of Airborne Ultrasonic Transducer") discloses an ultrasonic generator that solves this problem and allows the frequency of the ultrasonic waves to be generated to be variable. The ultrasonic generator disclosed in Non-Patent Document 1 is called a thermophone, and has a structure in which a metal film is provided on a heat-dissipating substrate with a thin heat-insulating layer interposed therebetween. In the ultrasonic generator of Non-Patent Document 1, when an electric current is applied to the metal film, the metal film generates heat, and the air in contact with the metal film is warmed to generate ultrasonic waves.
　非特許文献１の超音波発生装置は、金属膜に流す電流の周波数を変えることにより、発生させる超音波の周波数を変更することができる。しかしながら、非特許文献１の超音波発生装置は、電気、熱、超音波の順番にエネルギーを変換するため、損失が大きく変換効率が低いという問題や、大きな音圧の超音波を得るのが難しいという問題があった。 The ultrasonic generator of Non-Patent Document 1 can change the frequency of the ultrasonic waves to be generated by changing the frequency of the current applied to the metal film. However, since the ultrasonic generator of Non-Patent Document 1 converts energy in the order of electricity, heat, and ultrasonic waves, there are problems of large loss and low conversion efficiency, and it is difficult to obtain ultrasonic waves with a large sound pressure. There was a problem.
　また、特許文献２（特開平７－３２８５３９公報）に、別の超音波発生装置（電磁音響変換器）が開示されている。特許文献２の超音波発生装置は、電磁反発力により超音波を発生させる。なお、特許文献２の超音波発生装置は、従来の技術として、特許文献２の図５等に開示されている。本願の図１１に、特許文献２の超音波発生装置１０００を示す。 In addition, Patent Document 2 (Japanese Unexamined Patent Application Publication No. 7-328539) discloses another ultrasonic wave generator (electromagnetic acoustic transducer). The ultrasonic generator disclosed in Patent Document 2 generates ultrasonic waves by electromagnetic repulsion. The ultrasonic wave generator of Patent Document 2 is disclosed in FIG. 5 of Patent Document 2 and the like as conventional technology. FIG. 11 of the present application shows an ultrasonic generator 1000 of Patent Document 2. As shown in FIG.
　特許文献２の超音波発生装置１０００は、渦巻状コイル５０と、渦巻状コイル５０から一定の距離を空けて配置された円板状の導電性振動放射体５２と、渦巻状コイル５０にパルス電流を供給するパルス生成装置５１を備えている。パルス生成装置５１は、直流電源５１１と、コンデンサ５１２と、切替スイッチ５１３により構成されている。 切替スイッチ５１３は、コンデンサ５１２が接続される相手先を、直流電源５１１と渦巻状コイル５０のいずれか一方に切り替えることができる。 The ultrasonic generator 1000 of Patent Document 2 includes a spiral coil 50, a disk-shaped conductive vibration radiator 52 arranged at a certain distance from the spiral coil 50, and a pulse current applied to the spiral coil 50. is provided with a pulse generator 51 for supplying The pulse generator 51 is composed of a DC power supply 511 , a capacitor 512 and a switch 513 . The changeover switch 513 can switch the destination to which the capacitor 512 is connected to either the DC power supply 511 or the spiral coil 50 .
　特許文献２の超音波発生装置１０００は、まず、切替スイッチ５１３を直流電源５１１側に切り替えて、直流電源５１１から供給される電力をコンデンサ５１２に蓄積する。次に、切替スイッチ５１３を渦巻状コイル５０側に切り替えて、コンデンサ５１２から渦巻状コイル５０に瞬間的に大電流を供給する。 The ultrasonic generator 1000 of Patent Document 2 first switches the selector switch 513 to the DC power supply 511 side, and accumulates power supplied from the DC power supply 511 in the capacitor 512 . Next, the selector switch 513 is switched to the spiral coil 50 side, and a large current is instantaneously supplied from the capacitor 512 to the spiral coil 50 .
　コンデンサ５１２から渦巻状コイル５０に瞬間的に大電流を供給すると、その電流によって、渦巻状コイル５０から導電性振動放射体５２の方向に、電磁誘導による磁界が発生する。また、その磁界によって、導電性振動放射体５２に渦電流が誘導され、その渦電流によって、導電性振動放射体５２から渦巻状コイル５０の方向に、電磁誘導による磁界が発生する。 When a large current is momentarily supplied from the capacitor 512 to the spiral coil 50 , the current generates a magnetic field due to electromagnetic induction in the direction from the spiral coil 50 to the conductive vibration radiator 52 . The magnetic field induces an eddy current in the conductive vibration radiator 52 , and the eddy current generates a magnetic field by electromagnetic induction in the direction from the conductive vibration radiator 52 to the spiral coil 50 .
　このとき、渦巻状コイル５０から発生する磁界と、導電性振動放射体５２から発生する磁界が反発し合うため、導電性振動放射体５２が渦巻状コイル５０と反対の方向に動き、空気を押し出し、超音波が発生する。 At this time, since the magnetic field generated from the spiral coil 50 and the magnetic field generated from the conductive vibration radiator 52 repel each other, the conductive vibration radiator 52 moves in the direction opposite to the spiral coil 50, pushing out the air. , ultrasonic waves are generated.
　特許文献２の超音波発生装置１０００は、コンデンサ５１２から渦巻状コイル５０に供給される電流の通電時間を変更することにより、発生する超音波の周波数を変更することができると考えられる。しかしながら、特許文献２の超音波発生装置は、通電時間を変えると変換効率が急激に低下すると考えられるため、特定の通電時間で使用され、特定の周波数の超音波を発生させると考えられる。 It is believed that the ultrasonic generator 1000 of Patent Document 2 can change the frequency of the generated ultrasonic waves by changing the energization time of the current supplied from the capacitor 512 to the spiral coil 50 . However, the ultrasonic generator of Patent Document 2 is considered to be used for a specific energizing time and generate ultrasonic waves of a specific frequency, because it is thought that the conversion efficiency drops sharply when the energizing time is changed.
実公平４－２７２８０号公報Japanese Utility Model Publication No. 4-27280 特開平７－３２８５３９号公報JP-A-7-328539
　特許文献２の超音波発生装置１０００は、特許文献２の段落[０００４]に、「・・・・・・前述のように円板状の振動放射体５２を励振させる従前の電磁音響変換器では、図６（ａ）に示すような伸び振動と、図６（ｂ）に示すような曲げ振動とが同時に励起され、両者が結合した曲げ伸び振動、即ちポアソン結合による振動となる。」と記載されていることからも明らかなように、導電性振動放射体５２が、ある程度、大きな厚みを持った、金属の板によって作製されている。 The ultrasonic generator 1000 of Patent Document 2 is described in paragraph [0004] of Patent Document 2 as follows: "As described above, the conventional electromagnetic acoustic transducer that excites the disk-shaped vibration radiator 52 6(a) and bending vibration shown in FIG. 6(b) are simultaneously excited, and bending-extension vibration combining the two, that is, vibration due to Poisson coupling, is obtained." , the conductive vibration radiator 52 is made of a metal plate having a certain thickness.
　変換効率を高くするためには、導電性振動放射体５２は、薄く、軽いことが好ましい。導電性振動放射体５２が厚く、重いと、初動速度が遅くなってしまうからである。特許文献２の超音波発生装置１０００は、導電性振動放射体５２が、大きな厚みを持った、金属の板によって作製されているため、変換効率が低いという問題があった。 In order to increase the conversion efficiency, the conductive vibration radiator 52 is preferably thin and light. This is because if the conductive vibration radiator 52 is thick and heavy, the initial speed will be slow. The ultrasonic generator 1000 of Patent Document 2 has a problem that the conversion efficiency is low because the conductive vibration radiator 52 is made of a metal plate having a large thickness.
　なお、特許文献２の出願発明（特許文献２の図１等に開示された発明）は、導電性振動放射体を半球殻状（お椀状）にすることにより、形状を維持したまま、導電性振動放射体の厚みを小さくし、かつ、重さを軽くして、変換効率の向上をはかろうとしている。しかしながら、導電性振動放射体を半球殻状にすると、半球の中央部は渦巻状コイルから近いため大きな反発力を得ることができるが、半球の周辺部は渦巻状コイルから遠いため大きな反発力を得ることができず、特許文献２の出願発明は、総合的には、それほど大きく変換効率は向上していないと考えられる。 In addition, the application invention of Patent Document 2 (the invention disclosed in FIG. 1 of Patent Document 2, etc.) has a conductive vibration radiator formed into a hemispherical shell shape (bowl shape) while maintaining its shape. An attempt is being made to improve the conversion efficiency by reducing the thickness and weight of the vibration radiator. However, if the conductive vibration radiator is made into a hemispherical shell shape, the central part of the hemisphere is close to the spiral coil, so a large repulsive force can be obtained, but the peripheral part of the hemisphere is far from the spiral coil, so a large repulsive force can be obtained. Therefore, it is considered that the invention of Patent Document 2 does not improve the conversion efficiency so much as a whole.
　上述のとおり、特許文献２の超音波発生装置１０００は、導電性振動放射体５２が、大きな厚みを持った、金属の板によって作製されているため、変換効率が低いという問題があった。また、特許文献２の超音波発生装置１０００は、導電性振動放射体５２が、大きな厚みを持った、金属の板によって作製されているため、導電性振動放射体５２の主面の面積を大きくして、超音波の放射される領域を広範囲にすることが難しかった。 As described above, the ultrasonic generator 1000 of Patent Document 2 has the problem that the conversion efficiency is low because the conductive vibration radiator 52 is made of a thick metal plate. Further, in the ultrasonic generator 1000 of Patent Document 2, the conductive vibration radiator 52 is made of a metal plate having a large thickness. Therefore, it has been difficult to widen the area from which ultrasonic waves are radiated.
　本発明は上述した課題を解消するためになされたものであり、その手段として、本発明の一実施態様にかかる超音波発生装置は、表裏対向する第１主面および第２主面を備えたコイルと、テンションをかけた状態で、第１主面および第２主面の少なくとも一方側に配置され金属箔と、コイルにパルス電流を印加するパルス電流発生回路と、を備えたものとする。 SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems. A coil, a metal foil placed on at least one side of the first main surface and the second main surface under tension, and a pulse current generating circuit for applying a pulse current to the coil.
　本発明の一実施態様にかかる超音波発生装置は、渦電流を発生させ、反発する磁界を発生させる媒体に、テンションをかけた状態の金属箔を使用するため、変換効率が極めて高い。すなわち、本発明の一実施態様にかかる超音波発生装置は、媒体に、薄く、軽い金属箔を使用するため、変換効率が極めて高い。また、本発明の一実施態様にかかる超音波発生装置は、超音波を発生させる振動放射体に金属箔を使用するため、金属箔の主面の面積を大きくして、超音波の放射される領域を広範囲にすることが容易である。また、本発明の一実施態様にかかる超音波発生装置は、コイルに印加するパルス電流の通電時間を変えることにより、発生する超音波の周波数を変えることができる。 The ultrasonic generator according to one embodiment of the present invention uses a tensioned metal foil as a medium for generating an eddy current and a repelling magnetic field, so the conversion efficiency is extremely high. That is, the ultrasonic generator according to one embodiment of the present invention uses a thin and light metal foil as a medium, so the conversion efficiency is extremely high. Further, in the ultrasonic generator according to one embodiment of the present invention, since the metal foil is used as the vibration radiator for generating the ultrasonic waves, the area of the main surface of the metal foil is increased to radiate the ultrasonic waves. It is easy to widen the area. Further, the ultrasonic generator according to one embodiment of the present invention can change the frequency of the generated ultrasonic waves by changing the duration of the pulse current applied to the coil.
図１（Ａ）は、第１実施形態にかかる超音波発生装置１００の正面図である。図１（Ｂ）は、超音波発生装置１００の平面図である。FIG. 1A is a front view of the ultrasonic generator 100 according to the first embodiment. FIG. 1B is a plan view of the ultrasonic generator 100. FIG. 図２（Ａ）およびは（Ｂ）は、それぞれ、超音波発生装置１００の断面図である。2A and 2B are cross-sectional views of the ultrasonic generator 100, respectively. 図３（Ａ）は、超音波発生装置１００を正面方向から見た説明図である。図３（Ｂ）は、超音波発生装置１００を平面方向から見た説明図である。FIG. 3A is an explanatory diagram of the ultrasonic generator 100 viewed from the front. FIG. 3B is an explanatory diagram of the ultrasonic generator 100 viewed from the plane. 図４（Ａ）、（Ｂ）は、それぞれ、第２実施形態にかかる超音波発生装置２００の断面図である。4A and 4B are cross-sectional views of the ultrasonic generator 200 according to the second embodiment, respectively. 図５は、第３実施形態にかかる超音波発生装置３００の断面図である。FIG. 5 is a cross-sectional view of an ultrasonic generator 300 according to the third embodiment. 図６（Ａ）は、第４実施形態にかかる超音波発生装置４００の説明図である。図６（Ｂ）は、超音波発生装置４００が発生させる超音波の特性を示すグラフである。FIG. 6A is an explanatory diagram of an ultrasonic generator 400 according to the fourth embodiment. FIG. 6B is a graph showing the characteristics of the ultrasonic waves generated by the ultrasonic generator 400. As shown in FIG. 図７（Ａ）は、第５実施形態にかかる超音波発生装置５００の説明図である。図７（Ｂ）は、超音波発生装置５００が発生させる超音波の特性を示すグラフである。FIG. 7A is an explanatory diagram of an ultrasonic generator 500 according to the fifth embodiment. FIG. 7B is a graph showing characteristics of ultrasonic waves generated by the ultrasonic generator 500. FIG. 図８は、第６実施形態にかかる各超音波発生装置が発生させる超音波の特性を示すグラフである。FIG. 8 is a graph showing characteristics of ultrasonic waves generated by each ultrasonic generator according to the sixth embodiment. 図９は、第７実施形態にかかる超音波発生装置７００の説明図である。FIG. 9 is an explanatory diagram of an ultrasonic generator 700 according to the seventh embodiment. 図１０は、第８実施形態にかかる超音波発生装置８００の要部分解斜視図である。FIG. 10 is an exploded perspective view of essential parts of an ultrasonic generator 800 according to the eighth embodiment. 図１１は、従来の超音波発生装置１０００の説明図である。FIG. 11 is an explanatory diagram of a conventional ultrasonic generator 1000. As shown in FIG.
　以下、図面とともに、本発明を実施するための形態について説明する。 Hereinafter, the embodiments for carrying out the present invention will be described along with the drawings.
　なお、各実施形態は、本発明の実施の形態を例示的に示したものであり、本発明が実施形態の内容に限定されることはない。また、異なる実施形態に記載された内容を組合せて実施することも可能であり、その場合の実施内容も本発明に含まれる。また、図面は、明細書の理解を助けるためのものであって、模式的に描画されている場合があり、描画された構成要素または構成要素間の寸法の比率が、明細書に記載されたそれらの寸法の比率と一致していない場合がある。また、明細書に記載されている構成要素が、図面において省略されている場合や、個数を省略して描画されている場合などがある。 It should be noted that each embodiment exemplifies the embodiment of the present invention, and the present invention is not limited to the content of the embodiment. Moreover, it is also possible to combine the contents described in different embodiments, and the contents of the implementation in that case are also included in the present invention. In addition, the drawings are intended to aid understanding of the specification, and may be schematically drawn, and the drawn components or the dimensional ratios between the components may not be the same as those described in the specification. The proportions of those dimensions may not match. In addition, there are cases where constituent elements described in the specification are omitted in the drawings, or where the number of constituent elements is omitted.
　［第１実施形態］
　図１（Ａ）、（Ｂ）、図２（Ａ）、（Ｂ）、図３（Ａ）、（Ｂ）に、それぞれ、第１実施形態にかかる超音波発生装置１００を示す。ただし、図１（Ａ）は、超音波発生装置１００の正面図である。図１（Ｂ）は、超音波発生装置１００の平面図である。図２（Ａ）およびは（Ｂ）は、それぞれ、超音波発生装置１００の断面図である。図３（Ａ）は、超音波発生装置１００を正面方向から見た説明図である。図３（Ｂ）は、超音波発生装置１００を平面方向から見た説明図である。なお、図２（Ａ）は、図２（Ｂ）の一点鎖線Ｙ－Ｙ部分を示し、図２（Ｂ）は、図２（Ａ）の一点鎖線Ｘ－Ｘ部分を示している。また、図１（Ａ）、（Ｂ）、図２（Ａ）、（Ｂ）においては、それぞれ、パルス電流発生回路４の図示を省略している。 [First embodiment]
1(A), (B), FIGS. 2(A), (B), and FIGS. 3(A), (B) respectively show an ultrasonic generator 100 according to the first embodiment. However, FIG. 1A is a front view of the ultrasonic generator 100. FIG. FIG. 1B is a plan view of the ultrasonic generator 100. FIG. 2A and 2B are cross-sectional views of the ultrasonic generator 100, respectively. FIG. 3A is an explanatory diagram of the ultrasonic generator 100 viewed from the front. FIG. 3B is an explanatory diagram of the ultrasonic generator 100 viewed from the plane. Note that FIG. 2(A) shows the dashed-dotted line YY portion of FIG. 2(B), and FIG. 2(B) shows the dashed-dotted line XX portion of FIG. 2(A). 1A, 1B, 2A and 2B, illustration of the pulse current generating circuit 4 is omitted.
　超音波発生装置１００は、枠体１を備えている。枠体１は、中空部１ａと、１対の導出孔１ｂ、１ｃを備えている。導出孔１ｂ、１ｃは、後述するコイル２の１対の端部２ｃ、２ｄを、外部に導出するためのものである。枠体１の材質は任意であるが、たとえば、樹脂、セラミック、金属、木材、ガラスなどを使用することができる。また、枠体１の形状も任意であるが、本実施形態においては、平面方向から見て矩形とした。なお、本発明において、枠体１は必須の構成ではなく、他の構造を用いたり、省略したりしてもよい。 The ultrasonic generator 100 includes a frame 1. The frame 1 has a hollow portion 1a and a pair of outlet holes 1b and 1c. The lead- out holes 1b and 1c are for leading out a pair of ends 2c and 2d of the coil 2, which will be described later, to the outside. Although the material of the frame 1 is arbitrary, for example, resin, ceramic, metal, wood, glass, etc. can be used. Also, the shape of the frame 1 is arbitrary, but in this embodiment, it is rectangular when viewed from the plane direction. In addition, in the present invention, the frame 1 is not an essential component, and other structures may be used or omitted.
　超音波発生装置１００は、コイル２を備えている。コイル２の材質、形状等は任意であるが、本実施形態においては、外表面に絶縁被覆（図示せず）が形成された導線である銅線を、単層に渦巻状に巻いたものを使用した。コイル２は、表裏対向する第１主面２ａおよび第２主面２ｂを備えている。コイル２は、１対の端部２ｃ、２ｄを備えている。 The ultrasonic generator 100 includes a coil 2. The coil 2 may be of any material, shape, etc., but in the present embodiment, a copper wire, which is a conductive wire with an insulating coating (not shown) formed on the outer surface, is spirally wound into a single layer. used. The coil 2 has a first main surface 2a and a second main surface 2b facing each other. The coil 2 has a pair of ends 2c, 2d.
　なお、コイル２の導線の材質、直径などは任意であり、銅線に代えて、Ａｇ線や、Ｎｉ線、Ａｌ線、Ｍｇ線、Ｗ線、Ｍｏ線、Ａｕ線、ニッケルクロム合金線などを使用してもよい。また、導線の外表面に形成した絶縁被覆の材質は任意であり、たとえば、エナメルを使用することができる。なお、本発明において、コイル２の導線の外表面の絶縁被覆は必須の構成ではなく、省略することも可能である。また、導線を巻いたコイル２に代えて、基板等の上に印刷したパターン電極等からなるコイルを使用してもよい。なお、この場合においては、パターン電極の上に絶縁被覆を形成してもよいし、形成しなくてもよい。 The material and diameter of the conductor wire of the coil 2 are arbitrary, and instead of the copper wire, Ag wire, Ni wire, Al wire, Mg wire, W wire, Mo wire, Au wire, nickel-chromium alloy wire, etc. may be used. may be used. Any material can be used for the insulating coating formed on the outer surface of the conductor, and for example, enamel can be used. In the present invention, the insulating coating on the outer surface of the conductor wire of the coil 2 is not an essential component, and can be omitted. Also, instead of the coil 2 wound with conductive wire, a coil made of patterned electrodes or the like printed on a substrate or the like may be used. In this case, the insulating coating may or may not be formed on the pattern electrodes.
　コイル２が、枠体１の中空部１ａに収容されている。コイル２の端部２ｃが枠体１の導出孔１ｂから外部に導出され、コイル２の端部２ｄが枠体１の導出孔１ｃから外部に導出されている。 The coil 2 is accommodated in the hollow portion 1a of the frame 1. An end portion 2c of the coil 2 is led out from the lead-out hole 1b of the frame 1, and an end portion 2d of the coil 2 is led out from the lead-out hole 1c of the frame 1 to the outside.
　超音波発生装置１００は、１枚の金属箔３を備えている。金属箔３の材質は任意であるが、電気導電性が高く、軽く、強度が高く、安価なものが好ましい。たとえば、アルミ箔、ＳＵＳ箔、銅箔、ニッケル箔、鉄箔等を使用することができる。アルミ箔を使用した場合には、電気導電性が高く、軽く、安価な金属箔３を得ることができる。ＳＵＳ箔を使用した場合には、強度の高い金属箔３を得ることができる。 The ultrasonic wave generator 100 is equipped with one sheet of metal foil 3 . The metal foil 3 may be made of any material, but preferably has high electrical conductivity, is light in weight, has high strength, and is inexpensive. For example, aluminum foil, SUS foil, copper foil, nickel foil, iron foil, etc. can be used. When aluminum foil is used, it is possible to obtain a metal foil 3 with high electrical conductivity, light weight, and low cost. When SUS foil is used, a metal foil 3 with high strength can be obtained.
　金属箔３の厚みは、たとえばアルミ箔などにおいては、３μｍ以上、１００μｍ以下であることが好ましい。金属箔３の厚みが３μｍ未満であると、金属箔３の強度が不十分になる虞があるからである。金属箔３の厚みが１００μｍを超えると、超音波発生装置１００の変換効率が低下したり、大きな音圧の超音波を発生できなくなったりする虞があるからである。なお、金属箔３の厚みについては、後の第６実施形態で検討する。 The thickness of the metal foil 3 is preferably 3 μm or more and 100 μm or less in the case of aluminum foil, for example. This is because if the thickness of the metal foil 3 is less than 3 μm, the strength of the metal foil 3 may be insufficient. This is because if the thickness of the metal foil 3 exceeds 100 μm, the conversion efficiency of the ultrasonic wave generator 100 may be lowered, or it may become impossible to generate ultrasonic waves with a large sound pressure. Note that the thickness of the metal foil 3 will be discussed later in the sixth embodiment.
　金属箔３は、外周の少なくとも一部が、テンションをかけた状態で枠体１に固定されている。具体的には、金属箔３は、枠体１の中空部１ａの一方側（コイル２の第１主面２ａ側）の開口を塞いだうえ、枠体１の側面を経由して反対側にまわり、枠体１の中空部１ａの他方側（コイル２の第２主面２ｂ側）の開口を塞いでいる。金属箔３の枠体１への固定方法は任意であり、たとえば、接着剤で固定することができる。なお、上述したとおり、本発明において枠体１は必須の構成ではなく、他の構造を用いたり、省略したりしてもよい。 At least a part of the outer periphery of the metal foil 3 is fixed to the frame 1 under tension. Specifically, the metal foil 3 closes the opening on one side of the hollow portion 1a of the frame 1 (the side of the first main surface 2a of the coil 2), and extends to the opposite side via the side surface of the frame 1. It turns around and closes the opening on the other side of the hollow portion 1a of the frame 1 (on the side of the second main surface 2b of the coil 2). Any method can be used to fix the metal foil 3 to the frame 1. For example, the metal foil 3 can be fixed with an adhesive. As described above, the frame 1 is not an essential component in the present invention, and other structures may be used or omitted.
　本実施形態の超音波発生装置１００は、１枚の金属箔３で枠体１の中空部１ａの両側の開口を塞いだ構造であるため、作製が容易であり、高い生産性を備えている。ただし、１枚の金属箔３を使用するのに代えて、枠体１の中空部１ａの一方側の開口を塞ぐ金属箔と、枠体１の中空部１ａの他方側の開口を塞ぐと金属箔とを別々に２枚用意し、別々に開口を塞いでもよい。 Since the ultrasonic generator 100 of this embodiment has a structure in which the openings on both sides of the hollow portion 1a of the frame 1 are closed with one sheet of metal foil 3, it is easy to manufacture and has high productivity. . However, instead of using one sheet of metal foil 3, the metal foil that closes the opening on one side of the hollow portion 1a of the frame 1 and the metal foil that closes the opening on the other side of the hollow portion 1a of the frame 1 Two foils may be separately prepared and the openings may be closed separately.
　本実施形態の超音波発生装置１００においては、コイル２の第１主面２ａと金属箔３との間、および、コイル２の第２主面２ｂと金属箔３との間に、隙間Ｓが形成されている。これらの隙間Ｓは、コイル２では、渦巻状の部分と、渦巻状の部分から一方の端部２ｃに向う部分とが、不可避的に交差するが、この交差を可能にするために形成したものである。ただし、たとえば、後述する第２実施形態の超音波発生装置２００のように、これらの隙間Ｓを省略し、コイル２と金属箔３とが接触するようにしてもよい。 In the ultrasonic generator 100 of the present embodiment, a gap S is provided between the first main surface 2a of the coil 2 and the metal foil 3 and between the second main surface 2b of the coil 2 and the metal foil 3. formed. In the coil 2, the spiral portion and the portion extending from the spiral portion to the one end 2c inevitably intersect, and these gaps S are formed to enable this intersection. is. However, for example, like an ultrasonic generator 200 of a second embodiment, which will be described later, these gaps S may be omitted and the coil 2 and the metal foil 3 may be brought into contact with each other.
　超音波発生装置１００は、図３（Ａ）、（Ｂ）に示すように、パルス電流発生回路４を備えている。 The ultrasonic generator 100 includes a pulse current generating circuit 4, as shown in FIGS. 3(A) and 3(B).
　パルス電流発生回路４は、図３（Ｂ）に示すように、１対の出力端子４ａ、４ｂを備えている。出力端子４ａはコイル２の一方の端部２ｃに接続され、出力端子４ｂはコイル２の他方の端部２ｄに接続されている。 The pulse current generating circuit 4 has a pair of output terminals 4a and 4b, as shown in FIG. 3(B). Output terminal 4 a is connected to one end 2 c of coil 2 , and output terminal 4 b is connected to the other end 2 d of coil 2 .
　パルス電流発生回路４は、図３（Ｂ）に示すように、さらに、直流電源４ｃと、コンデンサ４ｄと、切替スイッチ４ｅを備えている。 The pulse current generation circuit 4 further includes a DC power supply 4c, a capacitor 4d, and a switch 4e, as shown in FIG. 3(B).
　コンデンサ４ｄの種類は任意であるが、たとえば、積層セラミックコンデンサ、フィルムコンデンサ、電解コンデンサ等を使用することができる、ただし、積層セラミックコンデンサ、フィルムコンデンサを使用すれば、等価直列抵抗（ＥＳＲ）が低いため好ましい。 The type of the capacitor 4d is arbitrary, but for example, a laminated ceramic capacitor, a film capacitor, an electrolytic capacitor, etc. can be used. However, if a laminated ceramic capacitor or a film capacitor is used, the equivalent series resistance (ESR) is low. Therefore, it is preferable.
　パルス電流発生回路４は、出力端子４ａが、切替スイッチ４ｅの一方の切替端子に接続されている。切替スイッチ４ｅの他方の切替端子が、直流電源４ｃのプラス側の端子に接続されている。切替スイッチ４ｅの固定端子が、コンデンサ４ｄの一方の端子に接続されている。直流電源４ｃのマイナス側の端子とコンデンサ４ｄの他方の端子が、それぞれ、出力端子４ｂに接続されている。 The output terminal 4a of the pulse current generation circuit 4 is connected to one switching terminal of the changeover switch 4e. The other switching terminal of the changeover switch 4e is connected to the positive side terminal of the DC power supply 4c. A fixed terminal of the switch 4e is connected to one terminal of the capacitor 4d. The negative side terminal of the DC power supply 4c and the other terminal of the capacitor 4d are each connected to the output terminal 4b.
　パルス電流発生回路４は、切替スイッチ４ｅを切り替えることにより、コンデンサ４ｄが接続される相手先を、直流電源４ｃと、コイル２のいずれか一方に切り替えることができる。 The pulse current generation circuit 4 can switch the destination to which the capacitor 4d is connected to either the DC power supply 4c or the coil 2 by switching the selector switch 4e.
　次に、第１実施形態の超音波発生装置１００の使用方法について説明する。まず、図３（Ｂ）に示すように、切替スイッチ４ｅを直流電源４ｃ側に切り替えて、直流電源４ｃから供給される電力をコンデンサ４ｄに蓄積する。次に、切替スイッチ４ｅをコイル２側に切り替えて、コンデンサ４ｄからコイル２に瞬間的に大電流を供給する。すなわち、コンデンサ４ｄを放電させる。 Next, a method of using the ultrasonic generator 100 of the first embodiment will be described. First, as shown in FIG. 3B, the selector switch 4e is switched to the DC power supply 4c side, and the power supplied from the DC power supply 4c is stored in the capacitor 4d. Next, the selector switch 4e is switched to the coil 2 side, and a large current is instantaneously supplied to the coil 2 from the capacitor 4d. That is, the capacitor 4d is discharged.
　コンデンサ４ｄからコイル２に瞬間的に大電流を供給すると、その電流によって、コイル２から、コイル２の第１主面２ａおよび第２主面２ｂの両側に配置された金属箔３の方向に、それぞれ、電磁誘導による磁界が発生する。この結果、コイル２が発生させた磁界によって、第１主面２ａ側の金属箔３、および、第２主面２ｂ側の金属箔３に、それぞれ、渦電流が誘導される。そして、金属箔３に発生した渦電流によって、第１主面２ａ側の金属箔３、および、第２主面２ｂ側の金属箔３から、コイル２の方向に、それぞれ、電磁誘導による磁界が発生する。 When a large current is instantaneously supplied from the capacitor 4d to the coil 2, the current causes the coil 2 to move in the direction of the metal foils 3 arranged on both sides of the first main surface 2a and the second main surface 2b of the coil 2. Each generates a magnetic field due to electromagnetic induction. As a result, the magnetic field generated by the coil 2 induces eddy currents in the metal foil 3 on the first main surface 2a side and the metal foil 3 on the second main surface 2b side. Due to the eddy current generated in the metal foil 3, a magnetic field due to electromagnetic induction is generated in the direction of the coil 2 from the metal foil 3 on the first main surface 2a side and the metal foil 3 on the second main surface 2b side. Occur.
　このとき、コイル２から発生する磁界と、金属箔３から発生する磁界が反発し合うため、コイル２の第１主面２ａ側の金属箔３、および、コイル２の第２主面２ｂ側の金属箔３が、それぞれ、コイル２から離れる方向に動く。この結果、それぞれの金属箔３によって空気が押し出され、図３（Ａ）に示すように、超音波発生装置１００の両側（図３（Ａ）における上下両側）に超音波が発生する。 At this time, since the magnetic field generated from the coil 2 and the magnetic field generated from the metal foil 3 repel each other, the metal foil 3 on the first main surface 2a side of the coil 2 and the second main surface 2b side of the coil 2 The metal foils 3 each move away from the coil 2 . As a result, air is pushed out by each metal foil 3, and as shown in FIG. 3A, ultrasonic waves are generated on both sides of the ultrasonic generator 100 (upper and lower sides in FIG. 3A).
　超音波発生装置１００は、以上の動作を所定周期で繰り返すことにより、パルス状に超音波を発生させることができる。 The ultrasonic generator 100 can generate pulsed ultrasonic waves by repeating the above operation at a predetermined cycle.
　超音波発生装置１００は、すべての蓄積電荷を放電する場合、パルス電流発生回路４のコンデンサ４ｄの蓄積電荷量を変えることにより、コンデンサ４ｄからコイル２に印加されるパルス電流の通電時間が変わるため、発生する超音波の周波数を変えることができる。コンデンサ４ｄの蓄積電荷量は、コンデンサ４ｄに電力を供給する直流電源４ｃの電圧を変えるか、コンデンサ４ｄの容量を変えることにより、変えることができる。コンデンサ４ｄに電力を供給する直流電源４ｃの電圧を変え、かつ、コンデンサ４ｄの容量を変えてもよい。詳細については、後の第４実施形態および第５実施形態で、それぞれ説明する。 When the ultrasonic generator 100 discharges all the accumulated electric charges, by changing the accumulated electric charge amount of the capacitor 4d of the pulse current generating circuit 4, the conduction time of the pulse current applied from the capacitor 4d to the coil 2 is changed. , can change the frequency of the generated ultrasound. The amount of charge stored in the capacitor 4d can be changed by changing the voltage of the DC power supply 4c that supplies power to the capacitor 4d or by changing the capacity of the capacitor 4d. The voltage of the DC power supply 4c that supplies power to the capacitor 4d may be changed, and the capacity of the capacitor 4d may be changed. Details will be described later in a fourth embodiment and a fifth embodiment.
　なお、後の実施形態７（図９参照）のように、パルス電流発生回路７４に、切替スイッチ４ｅに代えて、半導体スイッチング素子７４ｅを設け、半導体スイッチング素子７４ｅを制御することによって、コンデンサ４ｄからコイル２に印加されるパルス電流の通電時間（放電時間）を変えるようにしてもよい。この場合も、発生させる超音波の周波数を変えることができる。 As in Embodiment 7 (see FIG. 9), the pulse current generation circuit 74 is provided with a semiconductor switching element 74e in place of the changeover switch 4e. By controlling the semiconductor switching element 74e, The energization time (discharge time) of the pulse current applied to the coil 2 may be changed. Also in this case, the frequency of the generated ultrasonic waves can be changed.
　第１実施形態の超音波発生装置１００は、上述したとおり、渦電流を発生させ、反発する磁界を発生させる媒体に、テンションをかけた状態の金属箔３を使用するため、複数のモードでの振動が発生せず、単一モードであり、変換効率が極めて高い。また、超音波発生装置１００によれば、単一周波数の良好な波形の超音波を発生させることができる。発生する超音波が単一周波数であることも、変換効率の向上に寄与している。また、超音波発生装置１００は、パルス電流発生回路４のコンデンサ４ｄの蓄積電荷量を変えることにより、発生する超音波の周波数を変えることができる。また、超音波発生装置１００は、金属箔３の主面の面積を大きくすることによって、容易に、超音波の放射される領域を広範囲化することができる。 As described above, the ultrasonic generator 100 of the first embodiment uses the metal foil 3 under tension as the medium that generates eddy currents and repulsive magnetic fields. Vibration-free, single-mode, and extremely high conversion efficiency. Further, according to the ultrasonic generator 100, it is possible to generate an ultrasonic wave having a single frequency and a good waveform. The fact that the generated ultrasonic waves are of a single frequency also contributes to the improvement of the conversion efficiency. Further, the ultrasonic wave generator 100 can change the frequency of the generated ultrasonic waves by changing the charge amount accumulated in the capacitor 4 d of the pulse current generating circuit 4 . Moreover, by increasing the area of the main surface of the metal foil 3, the ultrasonic generator 100 can easily widen the area from which the ultrasonic waves are radiated.
　［第２実施形態］
　図４（Ａ）、（Ｂ）に、それぞれ、第２実施形態に超音波発生装置２００を示す。図４（Ａ）、（Ｂ）は、それぞれ、超音波発生装置２００の断面図である。なお、図４（Ａ）は、図４（Ｂ）の一点鎖線Ｙ－Ｙ部分を示し、図４（Ｂ）は、図４（Ａ）の一点鎖線Ｘ－Ｘ部分を示している。また、図４（Ａ）、（Ｂ）においては、それぞれ、パルス電流発生回路４の図示を省略している。 [Second embodiment]
FIGS. 4A and 4B respectively show an ultrasonic generator 200 according to the second embodiment. 4A and 4B are cross-sectional views of the ultrasonic generator 200, respectively. Note that FIG. 4(A) shows the dashed-dotted line YY portion of FIG. 4(B), and FIG. 4(B) shows the dashed-dotted line XX portion of FIG. 4(A). 4A and 4B, illustration of the pulse current generating circuit 4 is omitted.
　第２実施形態の超音波発生装置２００は、第１実施形態の超音波発生装置１００の構成の一部に変更を加えた。 The ultrasonic generator 200 of the second embodiment has partially changed the configuration of the ultrasonic generator 100 of the first embodiment.
　具体的には、まず、超音波発生装置２００は、枠体２１の厚みを、超音波発生装置１００の枠体１の厚みよりも小さくした。具体的には、超音波発生装置２００は、枠体２１の厚みを、コイル２の導線（銅線）の直径と同じにした。この結果、超音波発生装置２００は、枠体２１の中空部２１ａの厚みも小さくなっている。なお、超音波発生装置２００の枠体２１は、超音波発生装置１００の導出孔１ｂ、１ｃと同様に、導出孔２１ｂ、２１ｃを備えている。 Specifically, first, in the ultrasonic generator 200 , the thickness of the frame 21 is made smaller than the thickness of the frame 1 of the ultrasonic generator 100 . Specifically, in the ultrasonic generator 200 , the thickness of the frame 21 is the same as the diameter of the conductive wire (copper wire) of the coil 2 . As a result, in the ultrasonic generator 200, the thickness of the hollow portion 21a of the frame 21 is also reduced. The frame 21 of the ultrasonic wave generator 200 is provided with lead-out holes 21b and 21c like the lead- out holes 1b and 1c of the ultrasonic wave generator 100 .
　また、超音波発生装置２００は、コイル２の渦巻状の部分の導線（銅線）と、渦巻状の部分から一方の端部２ｃに向う部分の導線が、領域Ｚにおいて交差するが、この領域Ｚにおける、それぞれの導線の厚みを、それぞれ、他の領域における導線の厚みの５０％の大きさにした。具体的には、それぞれの導線を、領域Ｚにおいて圧延するなどして、他の領域における導線の厚みの５０％の大きさにした。この結果、領域Ｚにおいて上下に交差する２本の導線の合計の厚みは、他の領域における導線の厚みと等しくなっている。 In addition, in the ultrasonic generator 200, the conducting wire (copper wire) of the spiral portion of the coil 2 and the conducting wire of the portion directed from the spiral portion to the one end 2c intersect in the region Z, but this region The thickness of each wire in Z was scaled to 50% of the thickness of the wires in the other regions, respectively. Specifically, each conductive wire is rolled in the region Z to have a thickness of 50% of the thickness of the conductive wire in the other regions. As a result, the total thickness of the two conductors vertically intersecting in the region Z is equal to the thickness of the conductors in the other regions.
　この結果、超音波発生装置２００は、コイル２が、第１主面２ａおよび第２主面２ｂの両側において、それぞれ、金属箔３と接触している。 As a result, in the ultrasonic generator 200, the coil 2 is in contact with the metal foil 3 on both sides of the first main surface 2a and the second main surface 2b.
　第２実施形態の超音波発生装置２００は、コイル２が、第１主面２ａおよび第２主面２ｂの両側において、それぞれ、金属箔３と近接（接触）しているため、コイル２から発生する磁界と、金属箔３から発生する磁界が、第１実施形態の超音波発生装置１００よりも、大きな力で反発し合う。そのため、超音波発生装置２００は、超音波発生装置１００よりも、さらに変換効率が向上している。また、超音波発生装置２００は、超音波発生装置１００よりも、発生する超音波の音圧が大きくなっている。 In the ultrasonic generator 200 of the second embodiment, since the coil 2 is in close proximity (contact) with the metal foil 3 on both sides of the first main surface 2a and the second main surface 2b, the ultrasonic wave generated from the coil 2 The magnetic field generated by the metal foil 3 and the magnetic field generated by the metal foil 3 repel each other with a greater force than the ultrasonic generator 100 of the first embodiment. Therefore, the ultrasonic generator 200 has a higher conversion efficiency than the ultrasonic generator 100 . In addition, the ultrasonic wave generator 200 generates a higher sound pressure of ultrasonic waves than the ultrasonic wave generator 100 does.
　［第３実施形態］
　図５に、第３実施形態にかかる超音波発生装置３００を示す。ただし、図５は、超音波発生装置３００の断面図である。なお、図５においては、パルス電流発生回路４の図示を省略している。 [Third embodiment]
FIG. 5 shows an ultrasonic generator 300 according to the third embodiment. However, FIG. 5 is a cross-sectional view of the ultrasonic generator 300 . 5, illustration of the pulse current generating circuit 4 is omitted.
　第３実施形態の超音波発生装置３００は、第１実施形態の超音波発生装置１００を、新たに設けた台座３５に固定した。具体的には、超音波発生装置１００の一方の主面（第１主面２ａ）を、台座３５に固定した。台座３５の材質は任意であるが、たとえば、樹脂、セラミック、金属などを使用することができる。また、超音波発生装置１００の台座３５への固定方法も任意であり、たとえば、超音波発生装置１００のコイル２の第１主面２ａ側の金属箔３を、台座３５の上側の主面に接着剤で接着するなどの方法をとることができる。 The ultrasonic generator 300 of the third embodiment is the ultrasonic generator 100 of the first embodiment fixed to a newly provided pedestal 35 . Specifically, one main surface (first main surface 2 a ) of the ultrasonic generator 100 was fixed to the base 35 . The material of the pedestal 35 is arbitrary, but for example, resin, ceramic, metal, or the like can be used. Also, the method of fixing the ultrasonic generator 100 to the base 35 is arbitrary. A method such as bonding with an adhesive can be used.
　超音波発生装置３００において、コンデンサ４ｄからコイル２に瞬間的に大電流を供給すると、コイル２から発生する磁界と、コイル２の第１主面２ａ側の金属箔３から発生する磁界、および、コイル２の第２主面２ｂ側の金属箔３から発生する磁界とが、それぞれ反発し合う。超音波発生装置３００においては、コイル２の第１主面２ａ側の金属箔３が台座３５に固定されているため、コイル２の第２主面２ｂ側の金属箔３のみが、コイル２から離れる方向に動く。この結果、コイル２の第２主面２ｂ側の金属箔３によって空気が押し出され、超音波が発生する。 In the ultrasonic generator 300, when a large current is instantaneously supplied from the capacitor 4d to the coil 2, the magnetic field generated from the coil 2, the magnetic field generated from the metal foil 3 on the first main surface 2a side of the coil 2, and The magnetic field generated from the metal foil 3 on the second main surface 2b side of the coil 2 repels each other. In the ultrasonic generator 300, since the metal foil 3 on the first main surface 2a side of the coil 2 is fixed to the base 35, only the metal foil 3 on the second main surface 2b side of the coil 2 is separated from the coil 2. move away. As a result, air is pushed out by the metal foil 3 on the side of the second main surface 2b of the coil 2, and ultrasonic waves are generated.
　第３実施形態の超音波発生装置３００は、コイル２の第２主面２ｂ側の金属箔３のみが動くため、超音波発生装置１００に比べて、より大きな反発力を発生させることができ、より高音圧の超音波を発生させることができる。超音波発生装置３００は、超音波発生装置１００に比べて、理論上においては、２倍の大きさの音圧の超音波を発生させることができる。 In the ultrasonic generator 300 of the third embodiment, only the metal foil 3 on the second main surface 2b side of the coil 2 moves, so compared to the ultrasonic generator 100, a larger repulsive force can be generated. Ultrasonic waves with a higher sound pressure can be generated. Theoretically, the ultrasonic generator 300 can generate ultrasonic waves with twice the sound pressure of the ultrasonic generator 100 .
　［第４実施形態］
　図６（Ａ）に、第４実施形態にかかる超音波発生装置４００を示す。ただし、図６（Ａ）は、超音波発生装置４００の説明図である。 [Fourth embodiment]
FIG. 6A shows an ultrasonic generator 400 according to the fourth embodiment. However, FIG. 6A is an explanatory diagram of the ultrasonic generator 400. FIG.
　第４実施形態の超音波発生装置４００は、第１実施形態の超音波発生装置１００の構成の一部に変更を加えた。 The ultrasonic generator 400 of the fourth embodiment has partially changed the configuration of the ultrasonic generator 100 of the first embodiment.
　具体的には、超音波発生装置１００は、パルス電流発生回路４の直流電源４ｃが電圧固定電源であったが、超音波発生装置４００は、これを変更し、パルス電流発生回路４４の直流電源４４ｃに、電圧可変電源を使用した。直流電源４４ｃは、供給する電圧を、たとえば、３０Ｖ、５０Ｖ、７５Ｖ、１００Ｖに切り替えることができる。 Specifically, in the ultrasonic generator 100, the DC power supply 4c of the pulse current generating circuit 4 was a fixed voltage power supply, but the ultrasonic generator 400 changes this to a DC power supply of the pulse current generating circuit 44. 44c used a voltage variable power supply. The DC power supply 44c can switch the voltage to be supplied to 30V, 50V, 75V, and 100V, for example.
　なお、パルス電流発生回路４のコンデンサ４ｄの容量は、２２μＦとした。 It should be noted that the capacitance of the capacitor 4d of the pulse current generating circuit 4 was set to 22 μF.
　超音波発生装置４００は、パルス電流発生回路４４の直流電源４４ｃが供給する電圧を変えることにより、コンデンサ４ｄの蓄積電荷量が変わるため、発生する超音波の周波数を変えることができる。 By changing the voltage supplied by the DC power supply 44c of the pulse current generating circuit 44, the ultrasonic generator 400 changes the amount of charge accumulated in the capacitor 4d, so that the frequency of the generated ultrasonic waves can be changed.
　図６（Ｂ）に、直流電源４４ｃが供給する電圧を、３０Ｖ、５０Ｖ、７５Ｖ、１００Ｖに切り替えた場合に、それぞれ発生する、超音波の波形を示す。なお、図６（Ｂ）のグラフにおいて、Ｙ軸は、発生した超音波を検知した超音波検知装置（マイクロフォン）の出力電圧を示している。 FIG. 6(B) shows the waveforms of ultrasonic waves generated when the voltage supplied by the DC power supply 44c is switched to 30V, 50V, 75V, and 100V. In the graph of FIG. 6B, the Y-axis indicates the output voltage of the ultrasonic detection device (microphone) that detected the generated ultrasonic waves.
　図６（Ｂ）から分かるように、超音波発生装置４００は、直流電源４４ｃの電圧を変えることにより、発生する超音波の周波数を変えることができる。具体的には、コンデンサ４ｄへ供給する電圧（充電電圧）を高くするにつれて、超音波の音圧が大きくなり、かつ、超音波の周波数が低くなる。 As can be seen from FIG. 6(B), the ultrasonic wave generator 400 can change the frequency of the generated ultrasonic waves by changing the voltage of the DC power supply 44c. Specifically, as the voltage (charging voltage) supplied to the capacitor 4d increases, the sound pressure of the ultrasonic waves increases and the frequency of the ultrasonic waves decreases.
　［第５実施形態］
　図７（Ａ）に、第５実施形態にかかる超音波発生装置５００を示す。ただし、図７（Ａ）は、超音波発生装置５００の説明図である。 [Fifth embodiment]
FIG. 7A shows an ultrasonic generator 500 according to the fifth embodiment. However, FIG. 7A is an explanatory diagram of the ultrasonic generator 500 .
　第５実施形態の超音波発生装置５００は、第１実施形態の超音波発生装置１００の構成の一部に変更を加えた。 The ultrasonic generator 500 of the fifth embodiment has partially changed the configuration of the ultrasonic generator 100 of the first embodiment.
　具体的には、超音波発生装置１００は、パルス電流発生回路４のコンデンサ４ｄが固定コンデンサであったが、超音波発生装置５００は、これを変更し、パルス電流発生回路５４のコンデンサ５４ｄに、可変コンデンサを使用した。コンデンサ（可変コンデンサ）５４ｄは、容量を、たとえば、２．２μＦ、２２μＦ、２２０μＦに切り替えることができる。 Specifically, in the ultrasonic generator 100, the capacitor 4d of the pulse current generating circuit 4 is a fixed capacitor, but in the ultrasonic generator 500, this is changed so that the capacitor 54d of the pulse current generating circuit 54 is A variable capacitor was used. Capacitor (variable capacitor) 54d can switch the capacitance to, for example, 2.2 μF, 22 μF, and 220 μF.
　なお、パルス電流発生回路４の直流電源４ｃがコンデンサ５４ｄに供給する電力の電圧は、１００Ｖとした。 The voltage of the power supplied to the capacitor 54d by the DC power supply 4c of the pulse current generating circuit 4 was set to 100V.
　超音波発生装置５００は、パルス電流発生回路５４のコンデンサ５４ｄの容量を変えることにより、コンデンサ５４ｄの蓄積電荷量が変わるため、発生する超音波の周波数を変えることができる。 By changing the capacity of the capacitor 54d of the pulse current generating circuit 54, the ultrasonic generator 500 changes the amount of charge accumulated in the capacitor 54d, so that the frequency of the generated ultrasonic waves can be changed.
　図７（Ｂ）に、コンデンサ５４ｄの容量を、２．２μＦ、２２μＦ、２２０μＦに切り替えた場合に、それぞれ発生する、超音波の波形を示す。図７（Ｂ）から分かるように、超音波発生装置５００は、コンデンサ５４ｄの容量を変えることにより、発生する超音波の周波数を変えることができる。具体的には、コンデンサ５４ｄの容量を大きくするにつれて、超音波の周波数が低くなる。 FIG. 7(B) shows the waveforms of ultrasonic waves generated when the capacitance of the capacitor 54d is switched to 2.2 μF, 22 μF, and 220 μF. As can be seen from FIG. 7B, the ultrasonic wave generator 500 can change the frequency of the generated ultrasonic waves by changing the capacitance of the capacitor 54d. Specifically, as the capacitance of the capacitor 54d is increased, the frequency of the ultrasonic wave is decreased.
　［第６実施形態］
　第６実施形態では、金属箔３の厚みが、発生する超音波の周波数に与える影響を検討した。 [Sixth embodiment]
In the sixth embodiment, the effect of the thickness of the metal foil 3 on the frequency of the generated ultrasonic waves was examined.
　第６実施形態においては、図１（Ａ）、（Ｂ）、図２（Ａ）、（Ｂ）、図３（Ａ）、（Ｂ）に示した第１実施形態の超音波発生装置１００の構造において、金属箔３の厚みを、１０μｍ、３０μｍ、５０μｍ、１００μｍの４通りに変えて、４つの超音波発生装置（図示せず）を作製した。なお、金属箔３には、それぞれ、アルミ箔を使用した。 In the sixth embodiment, the ultrasonic generator 100 of the first embodiment shown in FIGS. 1A, 1B, 2A, 2B, 3A, and 3B In terms of structure, four ultrasonic generators (not shown) were manufactured by changing the thickness of the metal foil 3 to 10 μm, 30 μm, 50 μm, and 100 μm. Aluminum foil was used for each of the metal foils 3 .
　図８に、各超音波発生装置から発生する、超音波の波形を示す。図８から分かるように、金属箔３の厚みが大きくなるにつれて、音圧は小さくなり、かつ、周波数は低くなる。変換効率を考えると、金属箔３の厚みは薄い方が好ましいが、強度が低下するので、変換効率と強度とのバランスを考慮して、適切な厚みを選択すればよい。 FIG. 8 shows the waveform of ultrasonic waves generated from each ultrasonic generator. As can be seen from FIG. 8, as the thickness of the metal foil 3 increases, the sound pressure decreases and the frequency decreases. Considering the conversion efficiency, it is preferable that the thickness of the metal foil 3 is thin.
　［第７実施形態］
　図９に、第７実施形態にかかる超音波発生装置７００を示す。ただし、図９は、超音波発生装置７００の説明図である。 [Seventh embodiment]
FIG. 9 shows an ultrasonic generator 700 according to the seventh embodiment. However, FIG. 9 is an explanatory diagram of the ultrasonic generator 700 .
　第７実施形態の超音波発生装置７００は、第１実施形態の超音波発生装置１００の構成の一部に変更を加えた。 The ultrasonic generator 700 of the seventh embodiment has partially changed the configuration of the ultrasonic generator 100 of the first embodiment.
　具体的には、超音波発生装置１００では、パルス電流発生回路４が切替スイッチ４ｅを備えていたが、超音波発生装置７００は、切替スイッチ４ｅを省略し、代わりに半導体スイッチング素子７４ｅを設けた。なお、本実施形態においては、半導体スイッチング素子７４ｅに一般的なトランジスタを使用したが、半導体スイッチング素子７４ｅの種類は任意であり、たとえば、ＦＥＴ（電界効果トランジスタ）などを使用してもよい。 Specifically, in the ultrasonic generator 100, the pulse current generating circuit 4 includes the changeover switch 4e, but in the ultrasonic generator 700, the changeover switch 4e is omitted, and a semiconductor switching element 74e is provided instead. . In this embodiment, a general transistor is used as the semiconductor switching element 74e, but the type of the semiconductor switching element 74e is arbitrary, and for example, an FET (Field Effect Transistor) or the like may be used.
　超音波発生装置７００は、半導体スイッチング素子７４ｅを制御することにより、コンデンサ４ｄからコイル２に印加されるパルス電流の通電時間（放電時間）を変えることができ、発生させる超音波の周波数を変えることができる。 By controlling the semiconductor switching element 74e, the ultrasonic generator 700 can change the energization time (discharge time) of the pulse current applied from the capacitor 4d to the coil 2, thereby changing the frequency of the ultrasonic waves to be generated. can be done.
　［第８実施形態］
　図１０に、第８実施形態にかかる超音波発生装置８００を示す。ただし、図８は、超音波発生装置８００の要部分解斜視図である。 [Eighth embodiment]
FIG. 10 shows an ultrasonic generator 800 according to the eighth embodiment. However, FIG. 8 is an exploded perspective view of the main part of the ultrasonic generator 800. FIG.
　第８実施形態の超音波発生装置８００は、第１実施形態の超音波発生装置１００の構成の一部に変更を加えた。 The ultrasonic generator 800 of the eighth embodiment has partially changed the configuration of the ultrasonic generator 100 of the first embodiment.
　具体的には、超音波発生装置１００では、単層に渦巻状に巻いたコイル２を使用したが、超音波発生装置８００はこれを変更し、図１０に示す、複数層に渦巻状に巻いた、一般にアルファ巻きと呼ばれるコイル８２を使用した。本実施形態のコイル８２は、下層８２ａと上層８２ｂの二層で構成されている。なお、図１０においては、下層８２ａと上層８２ｂが離れた状態で描写されているが、実際には、下層８２ａと上層８２ｂは、接触または近接している。 Specifically, the ultrasonic generator 100 uses the coil 2 spirally wound in a single layer. A coil 82, commonly referred to as an alpha winding, was used. The coil 82 of this embodiment is composed of two layers, a lower layer 82a and an upper layer 82b. Although the lower layer 82a and the upper layer 82b are depicted in FIG. 10 in a separated state, the lower layer 82a and the upper layer 82b are actually in contact or close to each other.
　超音波発生装置８００においても、コイル８２が、金属箔３に、電磁誘導による磁界を発生させる。なお、本実施形態においては、コイル８２の導線に断面が平板状のものを使用したが、他の実施形態と同じように、コイル８２の導線に断面が円形のものを使用してもよい。また、逆に、他の実施形態のコイル２に、コイル８２のように導線の断面が平板状のものを使用してもよい。 In the ultrasonic generator 800 as well, the coil 82 causes the metal foil 3 to generate a magnetic field by electromagnetic induction. In this embodiment, the conductor wire of the coil 82 has a flat cross section, but the conductor wire of the coil 82 may have a circular cross section as in the other embodiments. Conversely, a conductive wire having a flat cross section like the coil 82 may be used as the coil 2 of another embodiment.
　以上、第１実施形態～第８実施形態について説明した。しかしながら、本発明が上述した内容に限定されることはなく、発明の趣旨に沿って種々の変更をなすことができる。 The first to eighth embodiments have been described above. However, the present invention is not limited to the contents described above, and various modifications can be made along the spirit of the invention.
　たとえば、上記実施形態では、コイル２に、導線を単層に巻いたものを使用したが、これに代えて、導線を複数層に巻いたものを使用してもよい。また、コイル２の絶縁被覆は、コイル２と金属箔３との間に間隙があるような場合には、省略してもよい。 For example, in the above-described embodiment, the coil 2 is formed by winding a conductor wire in a single layer, but instead of this, a conductor wire wound in multiple layers may be used. Also, the insulating coating of the coil 2 may be omitted if there is a gap between the coil 2 and the metal foil 3 .
　また、上記実施形態では、コイル２に、導線を渦巻状に巻いたものを使用したが、コイルはこの形態には限られず、たとえば、基板の主面に導体パターンを渦巻状に印刷したものを使用してもよい。 In the above-described embodiment, the coil 2 is formed by spirally winding a conductive wire, but the coil is not limited to this form. may be used.
　また、上記実施形態では、金属箔３の形状が平面方向に見た場合に矩形であったが、金属箔３の形状は任意であり、たとえば、矩形に代えて、円形等としてもよい。 In addition, in the above embodiment, the shape of the metal foil 3 is rectangular when viewed in the planar direction, but the shape of the metal foil 3 is arbitrary, and may be circular instead of rectangular, for example.
　本発明の一実施態様にかかる超音波発生装置は、「課題を解決するための手段」の欄に記載したとおりである。 The ultrasonic generator according to one embodiment of the present invention is as described in the "Means for Solving the Problems" column.
　この超音波発生装置において、金属箔が、コイルの第１主面および第２主面の両側に、それぞれ配置されることも好ましい。この場合には、超音波発生装置の両側に、超音波を発生させることができる。 In this ultrasonic generator, it is also preferred that metal foils are arranged on both sides of the first main surface and the second main surface of the coil, respectively. In this case, ultrasonic waves can be generated on both sides of the ultrasonic generator.
　第１主面の側に配置された金属箔と、第２主面の側に配置された金属箔が、コイルを第１主面および第２主面の両側から包んだ、１枚の金属箔であることも好ましい。この場合には、超音波発生装置の作製が容易になり、生産性が向上する。 The metal foil arranged on the side of the first main surface and the metal foil arranged on the side of the second main surface wrap the coil from both sides of the first main surface and the second main surface. It is also preferable that In this case, fabrication of the ultrasonic generator is facilitated, and productivity is improved.
　中空部を備えた枠体を備え、コイルは、枠体の中空部に収容され、金属箔は、外周の少なくとも一部が、テンションをかけた状態で、枠体に固定されることも好ましい。この場合には、超音波発生装置の変換効率が高くなる。また、超音波発生装置の作製が容易になり、生産性が向上する。 It is also preferable that a frame having a hollow portion is provided, the coil is housed in the hollow portion of the frame, and the metal foil is fixed to the frame with at least a part of the outer circumference being under tension. In this case, the conversion efficiency of the ultrasonic generator increases. In addition, the ultrasonic generator can be manufactured easily, and the productivity is improved.
　コイルに絶縁被覆が施され、コイルと金属箔が接触していることも好ましい。この場合には、コイルと金属箔が近接するため、コイルから発生する磁界と、金属箔から発生する磁界が、大きな力で反発し合う。そのため、超音波発生装置の変換効率が高くなる。 It is also preferable that the coil is coated with insulation and that the coil and the metal foil are in contact. In this case, since the coil and the metal foil are close to each other, the magnetic field generated by the coil and the magnetic field generated by the metal foil repel each other with great force. Therefore, the conversion efficiency of the ultrasonic generator is increased.
　金属箔が、アルミ箔であることも好ましい。この場合には、電気導電性が高く、軽く、安価な金属箔を得ることができる。 It is also preferable that the metal foil is an aluminum foil. In this case, a metal foil with high electrical conductivity, light weight, and low cost can be obtained.
　金属箔の厚みは、たとえば金属箔がアルミ箔である場合、３μｍ以上、１００μｍ以下であることも好ましい。厚みが３μｍ未満であると、金属箔の強度が不十分になる虞があるからである。厚みが１００μｍを超えると、変換効率が低下したり、大きな音圧の超音波を発生することができなくなる虞があるからである。 The thickness of the metal foil is preferably 3 µm or more and 100 µm or less when the metal foil is aluminum foil, for example. This is because if the thickness is less than 3 μm, the strength of the metal foil may be insufficient. This is because if the thickness exceeds 100 μm, there is a risk that the conversion efficiency will decrease, or that it will be impossible to generate ultrasonic waves with a large sound pressure.
　コイルは、導線が、渦巻き状に、単層に巻かれたものであってもよい。あるいは、コイルは、導線が、渦巻き状に、複数層に巻かれたものであってもよい。 The coil may be a conductor wound in a spiral in a single layer. Alternatively, the coil may be a conductive wire wound in multiple layers spirally.
　パルス電流発生回路が、電源と、コンデンサと、切替スイッチを含むことも好ましい。この場合には、簡易な構成で、コイルにパルス電流を供給することができる。 It is also preferable that the pulse current generating circuit includes a power supply, a capacitor, and a changeover switch. In this case, a pulse current can be supplied to the coil with a simple configuration.
　コンデンサに印加する電圧を変更することにより、コンデンサの蓄積電荷量が可変であり、パルス電流発生回路からコイルに印加される、パルス電流の通電時間が可変であることも好ましい。この場合には、超音波発生装置が発生させる超音波の周波数を可変とすることができる。 By changing the voltage applied to the capacitor, it is also preferable that the amount of electric charge stored in the capacitor is variable, and the energization time of the pulse current applied to the coil from the pulse current generation circuit is also variable. In this case, the frequency of ultrasonic waves generated by the ultrasonic generator can be made variable.
　コンデンサの容量値を変更することにより、コンデンサの蓄積電荷量が可変であり、パルス電流発生回路からコイルに印加される、パルス電流の通電時間が可変であることも好ましい。この場合には、超音波発生装置が発生させる超音波の周波数を可変とすることができる。 By changing the capacitance value of the capacitor, it is also preferable that the amount of charge stored in the capacitor is variable, and the energization time of the pulse current applied to the coil from the pulse current generation circuit is also variable. In this case, the frequency of ultrasonic waves generated by the ultrasonic generator can be made variable.
　パルス電流発生回路が、電源と、コンデンサと、半導体スイッチング素子を含み、半導体スイッチング素子を制御することにより、パルス電流発生回路からコイルに印加される、パルス電流の通電時間が可変であることも好ましい。この場合には、超音波発生装置が発生させる超音波の周波数を可変とすることができる。 It is also preferable that the pulse current generation circuit includes a power supply, a capacitor, and a semiconductor switching element, and that the semiconductor switching element is controlled so that the energization time of the pulse current applied from the pulse current generation circuit to the coil is variable. . In this case, the frequency of ultrasonic waves generated by the ultrasonic generator can be made variable.
１・・・枠体
１ａ・・・中空部
１ｂ、１ｃ・・・導出孔
２、８２・・・コイル
２ａ・・・第１主面
２ｂ・・・第２主面
２ｃ、２ｄ・・・端部
３・・・金属箔
４、４４、５４、７４・・・パルス電流発生回路
４ａ、４ｂ・・・出力端子
４ｃ、４４ｃ・・・直流電源
４ｄ、５４ｄ・・・コンデンサ
７４ｅ・・・半導体スイッチング素子 REFERENCE SIGNS LIST 1 Frame body 1a Hollow portions 1b, 1c Lead- out holes 2, 82 Coil 2a First main surface 2b Second main surface 2c, 2d End Part 3... Metal foils 4, 44, 54, 74... Pulse current generation circuits 4a, 4b... Output terminals 4c, 44c... DC power supplies 4d, 54d... Capacitors 74e... Semiconductor switching element

Claims (11)

  1. 　表裏対向する第１主面および第２主面を備えたコイルと、
    　テンションをかけた状態で、前記第１主面および前記第２主面の少なくとも一方側に配置され金属箔と、
    　前記コイルにパルス電流を印加するパルス電流発生回路と、
    　を備えた超音波発生装置。     a coil having a first principal surface and a second principal surface facing each other;
    a metal foil placed on at least one side of the first main surface and the second main surface under tension;
    a pulse current generating circuit that applies a pulse current to the coil;
    Ultrasonic generator with.
  2. 　前記金属箔が、前記コイルの前記第１主面および前記第２主面の両側に、それぞれ配置された、
    　請求項１に記載された超音波発生装置。     the metal foils are arranged on both sides of the first main surface and the second main surface of the coil, respectively;
    The ultrasonic generator according to claim 1.
  3. 　前記第１主面の側に配置された前記金属箔と、前記第２主面の側に配置された前記金属箔が、前記コイルを前記第１主面および前記第２主面の両側から包んだ、１枚の金属箔である、
    　請求項２に記載された超音波発生装置。     The metal foil arranged on the side of the first principal surface and the metal foil arranged on the side of the second principal surface wrap the coil from both sides of the first principal surface and the second principal surface. It is a piece of metal foil,
    The ultrasonic generator according to claim 2.
  4. 　中空部を備えた枠体を備え、
    　前記コイルは、前記枠体の前記中空部に収容され、
    　前記金属箔は、外周の少なくとも一部が、テンションをかけた状態で、前記枠体に固定された、
    　請求項１ないし３のいずれか１項に記載された超音波発生装置。     A frame body having a hollow portion is provided,
    The coil is accommodated in the hollow portion of the frame,
    At least part of the outer periphery of the metal foil is fixed to the frame while tension is applied,
    The ultrasonic generator according to any one of claims 1 to 3.
  5. 　前記コイルに絶縁被覆が施され、
    　前記コイルと前記金属箔が接触している、
    　請求項１ないし４のいずれか１項に記載された超音波発生装置。     Insulating coating is applied to the coil,
    the coil and the metal foil are in contact,
    The ultrasonic generator according to any one of claims 1 to 4.
  6. 　前記金属箔が、アルミ箔である、
    　請求項１ないし５のいずれか１項に記載された超音波発生装置。     The metal foil is aluminum foil,
    The ultrasonic generator according to any one of claims 1 to 5.
  7. 　前記金属箔の厚みが、３μｍ以上、１００μｍ以下である、
    　請求項１ないし６のいずれか１項に記載された超音波発生装置。     The thickness of the metal foil is 3 μm or more and 100 μm or less.
    The ultrasonic generator according to any one of claims 1 to 6.
  8. 　前記パルス電流発生回路が、電源と、コンデンサと、切替スイッチを含む、
    　請求項１ないし７のいずれか１項に記載された超音波発生装置。     wherein the pulse current generating circuit includes a power supply, a capacitor, and a changeover switch;
    The ultrasonic generator according to any one of claims 1 to 7.
  9. 　前記コンデンサに印加する電圧を変更することにより、前記コンデンサの蓄積電荷量が可変であり、
    　前記パルス電流発生回路から前記コイルに印加される、前記パルス電流の通電時間が可変である、
    　請求項８に記載された超音波発生装置。     The amount of charge stored in the capacitor is variable by changing the voltage applied to the capacitor,
    The energization time of the pulse current applied to the coil from the pulse current generation circuit is variable.
    The ultrasonic generator according to claim 8.
  10. 　前記コンデンサの容量値を変更することにより、前記コンデンサの蓄積電荷量が可変であり、
    　前記パルス電流発生回路から前記コイルに印加される、前記パルス電流の通電時間が可変である、
    　請求項８または９に記載された超音波発生装置。     The amount of charge stored in the capacitor is variable by changing the capacitance value of the capacitor,
    The energization time of the pulse current applied to the coil from the pulse current generation circuit is variable.
    The ultrasonic generator according to claim 8 or 9.
  11. 　前記パルス電流発生回路が、電源と、コンデンサと、半導体スイッチング素子を含み、
    　前記半導体スイッチング素子を制御することにより、前記パルス電流発生回路から前記コイルに印加される、前記パルス電流の通電時間が可変である、
    　請求項１ないし７のいずれか１項に記載された超音波発生装置。
    　      the pulse current generating circuit includes a power supply, a capacitor, and a semiconductor switching element;
    The energization time of the pulse current applied to the coil from the pulse current generating circuit is variable by controlling the semiconductor switching element.
    The ultrasonic generator according to any one of claims 1 to 7.
PCT/JP2022/023692 2021-09-28 2022-06-13 Ultrasonic wave-generating device WO2023053590A1 (en)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6044814A (en) * 1983-08-22 1985-03-11 Oki Electric Ind Co Ltd Generating method of ultrasonic wave signal
JPS62281699A (en) * 1986-05-30 1987-12-07 Fujitsu Ltd Electromagnetic induction type sound source device
JPH07328539A (en) * 1994-06-14 1995-12-19 Yukio Kagawa Electromagnetic acoustic transducer

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6044814A (en) * 1983-08-22 1985-03-11 Oki Electric Ind Co Ltd Generating method of ultrasonic wave signal
JPS62281699A (en) * 1986-05-30 1987-12-07 Fujitsu Ltd Electromagnetic induction type sound source device
JPH07328539A (en) * 1994-06-14 1995-12-19 Yukio Kagawa Electromagnetic acoustic transducer

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