WO2020040131A1 - Pump device - Google Patents

Pump device Download PDF

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Publication number
WO2020040131A1
WO2020040131A1 PCT/JP2019/032422 JP2019032422W WO2020040131A1 WO 2020040131 A1 WO2020040131 A1 WO 2020040131A1 JP 2019032422 W JP2019032422 W JP 2019032422W WO 2020040131 A1 WO2020040131 A1 WO 2020040131A1
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WO
WIPO (PCT)
Prior art keywords
piezoelectric pump
pump
voltage
piezoelectric
frequency
Prior art date
Application number
PCT/JP2019/032422
Other languages
French (fr)
Japanese (ja)
Inventor
健二朗 岡口
Original Assignee
株式会社村田製作所
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Filing date
Publication date
Application filed by 株式会社村田製作所 filed Critical 株式会社村田製作所
Publication of WO2020040131A1 publication Critical patent/WO2020040131A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
    • B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
    • B06B1/00—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
    • B06B1/02—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy
    • B06B1/06—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B43/00—Machines, pumps, or pumping installations having flexible working members
    • F04B43/02—Machines, pumps, or pumping installations having flexible working members having plate-like flexible members, e.g. diaphragms
    • F04B43/04—Pumps having electric drive
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B45/00—Pumps or pumping installations having flexible working members and specially adapted for elastic fluids
    • F04B45/04—Pumps or pumping installations having flexible working members and specially adapted for elastic fluids having plate-like flexible members, e.g. diaphragms
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B45/00—Pumps or pumping installations having flexible working members and specially adapted for elastic fluids
    • F04B45/04—Pumps or pumping installations having flexible working members and specially adapted for elastic fluids having plate-like flexible members, e.g. diaphragms
    • F04B45/047—Pumps having electric drive
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N30/00—Piezoelectric or electrostrictive devices
    • H10N30/80—Constructional details

Definitions

  • the present invention relates to a pump device, and more particularly to a pump device including a piezoelectric pump.
  • a pump device equipped with a piezoelectric pump has been used as a gas suction device or a pressure device.
  • the piezoelectric pump is driven by the vibration of the piezoelectric element.
  • the size of the pump device can be reduced.
  • the piezoelectric element vibrates periodically by applying an AC voltage to the piezoelectric element. Thereby, the pressure in the container can be changed.
  • the frequency of the applied AC voltage is called a driving frequency of the piezoelectric pump.
  • the driving frequency of the piezoelectric pump is predetermined at room temperature.
  • the piezoelectric pump when the temperature of the piezoelectric pump is lower than the normal temperature, the output decreases, and when the temperature of the piezoelectric pump becomes higher than the normal temperature, the electric efficiency decreases.
  • the piezoelectric pump has a temperature characteristic. Therefore, as a technique for correcting the temperature characteristics of the piezoelectric pump, use of a temperature compensation technique used in a crystal oscillator can be considered.
  • a thermistor is provided outside the crystal oscillator to detect an environmental temperature, and compensate for the oscillation frequency of the crystal according to the detected temperature.
  • a pump device including a piezoelectric pump, which can drive the piezoelectric pump in accordance with the temperature of the piezoelectric pump.
  • a piezoelectric pump A voltage detection unit that detects an applied voltage applied to the piezoelectric pump, A control unit that drives the piezoelectric pump based on the applied voltage at a first frequency outside a driving frequency band capable of driving the piezoelectric pump, and determines a second frequency within the driving frequency band, It is a pump apparatus provided with.
  • the pump device of the present invention in a pump device including a piezoelectric pump, it is possible to provide a pump device that can be driven according to the temperature of the piezoelectric pump.
  • FIG. 6 is a graph showing the relationship between output voltage Vo and temperature at different frequencies.
  • Flow chart showing the flow of drive control of the piezoelectric pump according to the first embodiment.
  • FIG. 4 is a graph showing an example of a relationship between time and temperature of a piezoelectric pump in drive control.
  • FIG. 4 is a graph showing an example of a relationship between time and frequency in drive control.
  • Graph showing the electrical efficiency of the pump device 5 is a circuit diagram showing a modification of the drive circuit and the voltage detection circuit according to the first embodiment. Explanatory diagram showing the direction in which a fluid flows in Embodiment 2.
  • FIG. 6 is a graph showing a relationship between time and pressure of the pump device according to the second embodiment.
  • Block diagram of a pump device according to Embodiment 3. Flow chart showing the flow of drive control of the piezoelectric pump according to the third embodiment.
  • Circuit diagram of drive circuit and voltage detection circuit in Embodiment 3 Circuit diagram of an amplifier circuit according to Embodiment 3. Explanatory drawing showing the direction in which a fluid flows in Embodiment 4.
  • Circuit diagram of drive circuit and voltage detection circuit in Embodiment 4
  • a pump device includes a piezoelectric pump, a voltage detection unit that detects an applied voltage applied to the piezoelectric pump, and a first frequency outside a driving frequency band capable of driving the piezoelectric pump.
  • a control unit that drives the piezoelectric pump based on the applied voltage and determines a second frequency in the drive frequency band.
  • the voltage applied to the piezoelectric pump at the first frequency outside the driving frequency band of the piezoelectric pump is detected. Since the value of the applied voltage corresponds to the temperature of the piezoelectric pump, the second frequency for driving the piezoelectric pump is determined based on the detected applied voltage, so that an appropriate value corresponding to the temperature change of the piezoelectric pump can be obtained.
  • the piezoelectric pump can be driven at an appropriate frequency. Thus, the output of the piezoelectric pump at low temperatures and the electrical efficiency at high temperatures can be improved.
  • an impedance element electrically connected to the piezoelectric pump may be provided, and the voltage detection unit may measure the applied voltage from a voltage divided by the piezoelectric pump and the impedance element. According to such a configuration, the applied voltage of the piezoelectric pump can be easily detected.
  • a power supply unit that supplies power to the piezoelectric pump may be provided, and the control unit may be connected to the power supply unit and adjust power supplied to the piezoelectric pump according to an output voltage of the piezoelectric pump. . According to such a configuration, since the power supplied from the power supply unit can be adjusted according to the output voltage of the piezoelectric pump, overheating of the piezoelectric pump can be prevented.
  • control unit may be configured to perform the second step based on a modeled relationship between the capacity of the piezoelectric pump and the temperature of the piezoelectric pump, or a relationship between the output voltage of the piezoelectric pump and the temperature of the piezoelectric pump. May be determined.
  • the impedance element may be a resistor.
  • the impedance element may be an inductor.
  • the input voltage when detecting the divided output voltage may be lower than when the piezoelectric pump is driven in a driving frequency band. According to such a configuration, power consumption can be reduced.
  • FIG. 1 is a schematic sectional view of a piezoelectric pump.
  • FIG. 2 is an explanatory diagram showing the operation of the piezoelectric pump.
  • the piezoelectric pump 21 includes a cover plate 22, a channel plate 23, an opposing plate 24, an adhesive layer 25, a vibration plate 26, a piezoelectric element 27, an insulating plate 28, a power supply plate 29, a spacer plate 30, and a cover plate 31 in this order. Laminated.
  • the piezoelectric pump 21 is thin in the stacking direction and has a rectangular shape in a plan view (as viewed from the stacking direction).
  • a suction port 33 is formed on the cover plate 22 side of the piezoelectric pump 21.
  • a discharge port 34 is formed on the lid plate 31 side of the piezoelectric pump 21.
  • a circular channel hole 37 is formed in the cover plate 22.
  • the channel plate 23 has a circular opening 38 formed therein.
  • the opening 38 communicates with the channel hole 37.
  • the diameter of the opening 38 is larger than the diameter of the flow path hole 37.
  • the opposing plate 24 is made of metal.
  • An external connection terminal 35 protruding outward and a circular suction port 33 are formed in the facing plate 24.
  • the suction port 33 communicates with the opening 38.
  • the diameter of the suction port 33 is smaller than the diameter of the opening 38.
  • a bendable movable portion 39 is formed around the suction port 33 of the opposing plate 24.
  • the adhesive layer 25 is formed in a frame shape so as to overlap the frame portion 44 of the diaphragm 26.
  • the adhesive layer 25 is composed of a thermosetting resin such as an epoxy resin and contains a plurality of conductive particles having a substantially uniform particle size. Thereby, the opposing plate 24 and the vibration plate 26 can be electrically conducted through the conductive particles of the adhesive layer 25.
  • the diaphragm 26 is made of metal such as SUS301, for example.
  • the vibration plate 26 faces the opposing plate 24 at a predetermined interval.
  • the gap between the opposing plate 24 and the diaphragm 26 constitutes a pump chamber 40.
  • the diaphragm 26 has a central portion 41, a hitting portion 42, a connecting portion 43, and a frame portion 44.
  • the central portion 41 has a circular shape in plan view, and is disposed at the center of the diaphragm 26.
  • the frame portion 44 has a frame shape in a plan view, and is arranged around the diaphragm 26.
  • the connecting portion 43 has a beam shape and connects the central portion 41 and the frame portion 44.
  • the hitting portion 42 has a circular shape in plan view, and is disposed near a boundary between the central portion 41 and the connecting portion 43.
  • the striking section 42 is arranged such that the center thereof faces the suction port 33.
  • the diameter of the hitting portion 42 is larger than the diameter of the suction port 33.
  • the hitting portion 42 and the frame portion 44 are thicker than the central portion 41 and the connecting portion 43.
  • the diaphragm 26 has an opening (not shown) surrounded by the components of the diaphragm 26 described above.
  • the pump chamber 40 communicates with the pump chamber 46 through the opening.
  • the piezoelectric element 27 is configured by providing electrodes on both main surfaces of a thin plate made of a piezoelectric material.
  • the piezoelectric element 27 has such a piezoelectric property that its area increases or decreases in the in-plane direction when an electric field is applied in the thickness direction.
  • the piezoelectric element 27 has a disk shape and is attached to the upper surface of the central portion 41 of the diaphragm 26.
  • the electrode on the lower surface of the piezoelectric element 27 is electrically connected to the external connection terminal 35 via the vibration plate 26, the adhesive layer 25, and the opposing plate 24.
  • the insulating plate 28 is made of an insulating resin.
  • the insulating plate 28 has a rectangular opening in a plan view.
  • the power supply plate 29 is made of metal.
  • the power supply plate 29 is formed with a rectangular opening in plan view, an internal connection terminal 45 protruding from the opening of the power supply plate 29, and an external connection terminal 36 protruding outward.
  • the tip of the internal connection terminal 45 is soldered to an electrode on the upper surface of the piezoelectric element 27.
  • the spacer plate 30 is made of resin.
  • the spacer plate 30 is formed with a rectangular opening in plan view.
  • the openings of the insulating plate 28, the power supply plate 29, and the spacer plate 30 communicate with each other to form a pump chamber 46.
  • the cover plate 31 is formed with a circular discharge port 34 in plan view.
  • the discharge port 34 communicates with the pump chamber 46 and the outside.
  • FIG. 2 is a schematic diagram showing the operation of the piezoelectric pump 21.
  • the piezoelectric pump 21 when an AC drive voltage is applied to the external connection terminals 35 and 36, the piezoelectric element 27 tries to expand and contract isotropically in the in-plane direction, and the piezoelectric element 27 and the vibration plate 26 are stacked. Flexural vibration in the thickness direction occurs concentrically. This bending vibration is a higher-order resonance mode, in which the frame portion 44 becomes a fixed portion, the center of the central portion 41 becomes an antinode of the first vibration, and the center of the hitting portion 42 becomes an antinode of the second vibration.
  • the vibration of the striking section 42 is transmitted to the movable section 39 via the fluid facing the striking section 42.
  • Fluid flows from the vicinity of the suction port 33 in the pump chamber 40 to the outer peripheral side of the movable portion 39 by coupling the vibration of the impact portion 42 and the vibration of the movable portion 39.
  • a negative pressure is generated around the suction port 33 in the pump chamber 40, and the fluid is sucked from the suction port 33 into the pump chamber 46.
  • a positive pressure is generated inside the pump chamber 46, and the positive pressure is released at the discharge port 34 of the cover plate 31. Therefore, the fluid sucked into the pump chambers 40 and 46 via the suction port 33 flows out of the pump chambers 40 and 46 via the discharge port 34.
  • the piezoelectric element 27, the diaphragm 26, and the opposing plate 24 of the piezoelectric pump 21 are called an engine.
  • the state in which the piezoelectric pump 21 is driven is a state in which the engine of the piezoelectric pump 21 bends and vibrates.
  • the state in which the piezoelectric pump 21 is driven refers to a state in which a fluid is sucked into the piezoelectric pump 21 or a fluid is discharged from the piezoelectric pump 21.
  • the non-driven state in which the piezoelectric pump 21 is not driven is a state in which fluid is not sucked into the piezoelectric pump 21 or a state in which fluid is not discharged from the piezoelectric pump 21.
  • FIG. 3 is a graph showing the relationship between pressure and electrical efficiency at different temperatures.
  • FIG. 3 shows the driving when the piezoelectric pump 21 is at 40 ° C.
  • the graph Gb is at 23 ° C.
  • the graph Gc is at 10 ° C. when the back pressure of the piezoelectric pump 21 is 380 mmHg.
  • the relationship between frequency and air flow is shown.
  • the optimum driving frequency Fga of the graph Ga, the optimum driving frequency Fgb of the graph Gb, and the optimum driving frequency Fgc of the graph Gc are different from each other. Therefore, when the drive frequency is set to Fgb so as to drive optimally when the drive frequency is 23 ° C., at an environment temperature of 10 ° C., the flow rate of the piezoelectric pump 21 becomes zero at a back pressure of 380 mmHg. Do not work. As described above, the pump output decreases when the temperature decreases from room temperature.
  • FIG. 4 is a graph showing the relationship between pressure and electrical efficiency at different temperatures.
  • FIG. 4 shows the electrical efficiency at each temperature when driven at the frequency Fgb of FIG.
  • the graph Gd shows the relationship between the respective pressures and the electrical efficiency when the piezoelectric pump 21 is at 50 ° C., the graph Gh at 25 ° C., and the graph Ge at 0 ° C.
  • the peak value of the electric efficiency varies depending on the temperature, and the electric efficiency decreases particularly at a high temperature. If the electric efficiency is poor, for example, when a battery is used as a power supply, the life of the battery is shortened, and the frequency of battery replacement and charging is increased, thereby reducing usability.
  • FIG. 5 is a graph showing the relationship between the driving frequency and the impedance at normal temperature, for example, 20 ° C.
  • the frequency characteristic of the piezoelectric pump 21 has a resonance frequency fr and an anti-resonance frequency fa.
  • the resonance frequency fr is about 23.4 kHz
  • the anti-resonance frequency fa is about 24.5 kHz.
  • a driving frequency band Fw in which the piezoelectric pump can be driven is between the resonance frequency fr and the anti-resonance frequency fa.
  • the frequency band lower than the resonance frequency fr and the frequency band higher than the anti-resonance frequency fa are non-drive frequency bands Fz.
  • FIG. 6 is an equivalent circuit diagram modeling the piezoelectric pump 21.
  • the non-drive frequency band Fz has a frequency characteristic of the capacitor Ca.
  • the resonance frequency fr has a frequency characteristic of a series circuit Da including the inductor L, the capacitor Cb, and the resistor R.
  • the anti-resonance frequency fa has a frequency characteristic of a parallel circuit Db including the LCR series circuit Da and the capacitor C.
  • the impedance is determined only by the capacitance Ca of the piezoelectric pump 21, so that the impedance is relatively stable with respect to an input voltage or a back pressure and is sensitive to temperature.
  • the non-drive frequency band including the non-drive frequency is, for example, a frequency region excluding a region between a resonance frequency at which the impedance is minimum and an anti-resonance frequency at which the impedance is maximum (in other words, the impedance is C-characteristic).
  • FIG. 7 is a graph showing the relationship between the temperature of the piezoelectric pump and the rate of change of the capacity.
  • FIG. 7 shows the relationship between the capacitance and the temperature at the non-drive frequency.
  • the capacity Ca at normal temperature is determined by the dielectric constant, thickness, and area of the piezoelectric pump 21, but the error is small. Therefore, if the capacitance Ca at the non-drive frequency of the piezoelectric pump 21 is known, the temperature can be accurately detected.
  • the capacity C and the impedance Z of the piezoelectric pump 21 have a reciprocal relationship.
  • the relationship between the impedance Z, the frequency f, and the capacitance C is represented by the following equation.
  • the optimum drive frequency at each temperature is determined by the design of the piezoelectric pump 21, and if the current value is determined, the optimum frequency is determined from the relationship between the current value and the optimum drive frequency as shown in FIG.
  • the drive frequency is determined according to the temperature change of the piezoelectric pump 21. This corresponds to determining the drive frequency of the piezoelectric pump 21 according to the impedance change of the piezoelectric pump 21 at the non-drive frequency.
  • FIG. 9 is a graph showing the relationship between the output voltage of the piezoelectric pump and the drive frequency correction amount.
  • the output voltage is a parameter that changes according to the temperature of the piezoelectric pump. Therefore, by correcting the drive frequency according to the output voltage, it is possible to appropriately drive the piezoelectric pump 21 in response to a temperature change. Since the temperature of the piezoelectric pump 21 is higher as the output voltage is higher, the drive frequency is corrected to be lower.
  • FIG. 10 is a block diagram showing a pump device according to the first embodiment.
  • the pump device 11 includes a piezoelectric pump 21, a drive circuit 12 for driving the piezoelectric pump 21, a voltage detection circuit 13 for detecting an output voltage of the piezoelectric pump 21, a power supply circuit 14 for supplying power to the drive circuit 12, A control unit for determining a drive frequency of the pump;
  • the control unit 15 includes a processing unit 16 and a storage unit 17.
  • the control unit 15 may be, for example, an MCU (Micro Control Unit) in which the processing unit 16 and the storage unit 17 are integrated, or may be provided separately.
  • the processing unit 16 may be a CPU, a microchip, or an FPGA.
  • the storage unit 17 may be a memory, a hard disk, or an SSD. In the first embodiment, a case where an MCU is employed as the control unit 15 will be described as an example.
  • the relationship between the output voltage Vo and the drive frequency fo is stored in the storage unit 17 as a relational expression or a table.
  • the relationship between the output voltage Vo and the driving frequency fo is calculated in advance from the modeled relationship between the capacity C of the piezoelectric pump 21 and the temperature of the piezoelectric pump 21 or the relationship between the output voltage Vo and the temperature of the piezoelectric pump 21. By doing so, the processing time is shortened.
  • the pump device 11 according to the first embodiment is used, for example, in a suction device 51 as shown in FIG.
  • FIG. 11 is an explanatory diagram illustrating the flow of the fluid in the suction device according to the first embodiment.
  • the suction device 51 includes a container 53 in which a fluid is stored, a piezoelectric pump 21 that sucks the fluid from the container 53, a valve 55, and a tube 57 that connects the container 53, the valve 55, and the piezoelectric pump 21.
  • the fluid may be a liquid or a gas.
  • suction device examples include a milking machine, NPWT (Negative Pressure Wound Therapy), drainage, and a runny suction device.
  • NPWT Negative Pressure Wound Therapy
  • FIG. 11 one piezoelectric pump 21 is connected to the container 53, but two or more piezoelectric pumps 21 may be connected to the container 53 in series.
  • FIG. 12 is a circuit diagram of the drive circuit 12 and the voltage detection circuit 13.
  • the drive circuit 12 is, for example, an H-bridge circuit.
  • the drive circuit 12 has four FETs, a first FET 61, a second FET 62, a third FET 63, and a fourth FET 64. Each of the FETs is switched by a drive signal from the control unit 15 to the first to fourth FETs 61 to 64, and an AC voltage having a predetermined frequency is applied to the piezoelectric pump 21.
  • the input voltage Vc is applied from the power supply circuit 14 to the drains of the first FET 61 and the third FET 63.
  • the source of the first FET 61 is connected to the drain of the second FET 62 and the external connection terminal 35 of the piezoelectric pump 21.
  • the source of the third FET 63 is connected to the drain of the fourth FET 64 and the external connection terminal 36 of the piezoelectric pump 21.
  • the source of the second FET 62 and the source of the fourth FET 64 are connected to the voltage detection circuit 13.
  • the voltage detection circuit 13 includes an impedance element that is electrically connected to the piezoelectric pump 21. As the impedance element, for example, a resistor Rs is used.
  • the DC input voltage Vc supplied from the power supply circuit 14 as a power supply unit is divided by the first FET 61, the piezoelectric pump 21, the fourth FET 64, and the resistor Rs, or divided by the third FET 63, the piezoelectric pump 21, and the second FET 62. Pressed.
  • the voltage drop in the first to fourth FETs 61 to 64 is negligibly small. Therefore, the output voltage Vo is determined by the partial pressure between the piezoelectric pump 21 and the resistor Rs.
  • FIG. 13 shows the relationship between the output voltage Vo and the temperature at different frequencies.
  • the graph Gs shows the case where the non-driving frequency f1 in the non-driving frequency band Fz which is the first frequency is 15 kHz
  • the graph Gt shows the case where the non-driving frequency f1 is 32 kHz
  • the graph Gv shows the case where the non-driving frequency f1 is 45 kHz
  • the graph Gw shows the relationship between the output voltage Vo and the temperature when the non-drive frequency f1 is 60 kHz.
  • the temperature of the piezoelectric pump 21 can be measured by reading the output voltage Vo by the control unit 15.
  • the voltage detection circuit 13 is, for example, a resistor Rs.
  • the output voltage Vo of the drive circuit 12 can be detected by detecting the voltage between the resistors Rs.
  • the difference between the input voltage Vc and the output voltage Vo is the applied voltage (drive voltage) of the piezoelectric pump 21.
  • the applied voltage in this specification is a voltage that is a difference between the input voltage input to the drive circuit 12 and the output voltage output from the drive circuit 12. Since the input voltage Vc is supplied from the power supply circuit 14 at a voltage value according to an instruction from the control unit 15, the fluctuation of the output voltage Vo corresponds to the applied voltage of the piezoelectric pump 21. Therefore, detecting the applied voltage of the piezoelectric pump 21 can be substituted by detecting the output voltage Vo.
  • the voltage detection unit of the present invention includes a voltage detection circuit 13 and a control unit 15.
  • the control unit 15 also corresponds to the control unit of the present invention.
  • the non-drive frequency f1 for determining the drive frequency fo is preferably higher because the impedance Z of the piezoelectric pump 21 is lower. For example, it is better to satisfy the following relational expression. f1> 1.2 ⁇ fo Expression (2)
  • FIG. 14 is a flowchart showing the flow of drive control of the pump device 11.
  • FIG. 15 is a graph showing an example of the relationship between time and the temperature of the piezoelectric pump in drive control.
  • FIG. 16 is a graph showing an example of the relationship between time and frequency in drive control.
  • the temperature of the piezoelectric pump increases with time by driving the piezoelectric pump 21.
  • the frequency of the voltage applied to the piezoelectric pump is changed as shown in FIG.
  • step S1 the drive circuit 12 applies a voltage to the piezoelectric pump 21 at the non-drive frequency fz1 in the non-drive frequency band Fz between the time t1 and the time t2 according to an instruction from the processing unit 16 of the control unit 15. .
  • the period from time t1 to t2 is, for example, 30 msec.
  • the piezoelectric pump 21 does not perform the pump operation because the voltage of the non-drive frequency fz1 is applied.
  • current flows through the piezoelectric pump 21 and the voltage detection circuit 13.
  • the control unit 15 detects the voltage Vo divided by the voltage detection circuit 13. In this case, the voltage Vo is an applied voltage applied to the piezoelectric pump 21.
  • step S3 the processing unit 16 checks the detected voltage Vo against a table stored in the storage unit 17, and determines the driving frequency fw1 in the driving frequency band Fw corresponding to the voltage Vo.
  • step S4 the processing unit 16 sends a drive signal to the gate of each FET to the drive circuit 12 at the determined drive frequency fw1.
  • the drive circuit 12 drives the piezoelectric pump 21 at the drive frequency fw1 between time t2 and time t3 according to the transmitted drive signal.
  • the period between the time t2 and the time t3 is, for example, 2.5 seconds. That is, the time during which the voltage is applied to the piezoelectric pump 21 at the non-driving frequency fz1 is much smaller than the driving time of the pump.
  • the piezoelectric pump 21 can be driven at a drive frequency fw2 lower than the drive frequency fw1 with respect to the temperature rise of the piezoelectric pump 21.
  • the piezoelectric pump 21 increases, the voltage applied to the piezoelectric pump 21 increases, so that the control unit 15 controls the driving frequency to decrease.
  • steps S1 to S4 are repeated. Since the temperature rise of the piezoelectric pump 21 is saturated after time t5, the driving frequency fw3 for driving the piezoelectric pump 21 is the same.
  • FIG. 17 is a graph showing the life of the battery that drives the pump device.
  • FIG. 18 is a graph showing the electrical efficiency of the pump device.
  • the graph Gk in the case where the driving frequency is controlled according to the temperature has a longer life of the driving battery for driving the piezoelectric pump 21 than the graph Gm in which the driving frequency is not controlled. I have.
  • the control of the driving frequency was not performed, the battery voltage dropped to 3 V or less around the time when the driving time exceeded 450 hours.
  • the drive frequency is controlled in accordance with the temperature, the battery voltage has 3.2 V or more even when the drive time exceeds 600 minutes.
  • the graph Gn in the case where the driving frequency is controlled according to the temperature shows that the electric efficiency is improved over the entire temperature range as compared with the graph Gp in which the driving frequency is not controlled. I have.
  • the electric efficiency increases in a lower temperature region and a higher temperature region than normal temperature.
  • the power consumption of the piezoelectric pump 21 can be reduced by changing the driving frequency according to the temperature.
  • the pump device 11 includes the piezoelectric pump 21, a voltage detecting unit configured to detect the applied voltage applied to the piezoelectric pump 21, the voltage detecting circuit 13 and the control unit 15, and the piezoelectric pump 21.
  • a control unit 15 that determines a drive frequency fo which is a second frequency among the above.
  • the piezoelectric pump 21 can be driven at an appropriate frequency corresponding to the temperature change of the piezoelectric pump 21. Thereby, the electric efficiency of the piezoelectric pump 21 can be improved. Further, since the second frequency may be a constant frequency, the driving frequency fo can be determined faster than scanning the frequency to detect the driving frequency fo. Therefore, it is particularly suitable for a pump device used in a milking machine that repeats pump driving and stopping operations.
  • the voltage detection circuit 13 is not limited to a resistor and may be an inductor as long as the voltage detection circuit 13 is configured by an impedance element.
  • FIG. 19 is a circuit diagram showing a modification of the drive circuit and the voltage detection circuit according to the first embodiment.
  • the voltage detection circuit 13a has an inductor L1.
  • the input voltage Vc from the power supply circuit 14 is applied to one end of the inductor L1.
  • the other end of the inductor L1 is connected to respective drains of the first FET 61 and the third FET 63.
  • the voltage detection circuit 13 a replaces the connection destination of the voltage detection circuit 13 from GND to the power supply circuit 14.
  • the voltage detection circuit 13a can obtain the input voltage Vo to the drive circuit 12 by dividing the voltage of the inductor L1 and the piezoelectric pump 21. Since the other end of the drive circuit 12 is connected to the ground, the input voltage Vo is the voltage applied to the piezoelectric pump 21.
  • the impedance element when the impedance element is connected to the power supply side of the drive circuit 12, if the voltage division ratio of the impedance element is too small, the impedance may exceed the input range of the output voltage detection circuit. In such a case, the voltage may be divided.
  • FIG. 20 is an explanatory diagram illustrating a flowing direction of a fluid according to the second embodiment.
  • FIG. 21 is a graph showing a relationship between time and pressure of the pump device according to the second embodiment.
  • the pump device 11 according to the first embodiment has been used as a suction device for the suction device 51.
  • the pump device 11 of the second embodiment is used as a pressurizing device of the pressurizer 52.
  • a fluid such as air flows from the piezoelectric pump 21 toward the cuff 53a for storing the fluid.
  • the valve 55 When the valve 55 is in the closed state, the fluid flows from the piezoelectric pump 21 toward the cuff 53a, so that the pressure in the cuff 53a gradually increases.
  • the valve 55 is opened, the fluid in the cuff 53a is released, and the pressure in the cuff 53a decreases.
  • Specific examples of the pressurizer 52 include a sphygmomanometer, a massager, a pMDI (pressurized @ Metered-Dose @ Inhaler), and a nebulizer.
  • the pump device 11 according to the second embodiment includes the same components as the pump device 11 according to the first embodiment. Therefore, the configuration of the pump device 11 according to the second embodiment other than the matters described below is common to the pump device 11 of the first embodiment.
  • the output of the piezoelectric pump 21 can be improved by changing the drive frequency in accordance with the temperature change.
  • the driving frequency is not changed in accordance with the temperature change, if the driving time of the piezoelectric pump 21 becomes longer, the temperature of the piezoelectric pump 21 increases due to self-heating. As a result, the pressure of the fluid discharged from the piezoelectric pump 21 cannot be increased.
  • the drive frequency is changed according to the temperature change, the pressure of the fluid discharged from the piezoelectric pump 21 can be increased even when the temperature of the piezoelectric pump 21 increases. As a result, uniform pressurization of the fluid can be realized.
  • the driving frequency is changed in accordance with the temperature of the piezoelectric pump, thereby making it possible to start the piezoelectric pump 21 at a low temperature. Also, the pressurizing capacity can be maintained during continuous operation.
  • FIG. 22 is a block diagram of a pump device according to the third embodiment.
  • the pump device 11a according to the third embodiment has a function of preventing the piezoelectric pump 21 from being damaged by self-heating.
  • an upper limit value of the output voltage Vo is stored in addition to the relationship between the output voltage Vo and the driving frequency fo.
  • the pump device 11 according to the first embodiment is different from the pump device 11a according to the third embodiment.
  • the configuration other than this point and the matters described below is common to the pump device 11 of the first embodiment and the pump device 11a of the third embodiment.
  • FIG. 23 is a flowchart showing the flow of drive control of the pump device 11a.
  • the drive control of the pump device 11a according to the third embodiment is performed after the drive control of the pump device 11 according to the first embodiment. Therefore, the drive frequency fo for driving the piezoelectric pump 21 is determined by the processing of steps S1 to S4 of the first embodiment. Therefore, in step S11, the drive circuit 12 drives the piezoelectric pump 21 at the determined drive frequency fo according to the drive signal sent from the processing unit 16.
  • step S12 the drive circuit 12 applies a voltage to the piezoelectric pump 21 at the non-drive frequency f1 in the non-drive frequency band Fz according to the instruction from the processing unit 16.
  • the piezoelectric pump 21 does not perform the pump operation because the voltage of the non-drive frequency f1 is applied. However, current flows through the piezoelectric pump 21 and the voltage detection circuit 13.
  • the control unit 15 detects the voltage Vo divided by the voltage detection circuit 13. In this case, the voltage Vo is an applied voltage applied to the piezoelectric pump 21.
  • the processing unit 16 compares the detected voltage Vo with the upper limit value stored in the storage unit 17. If the voltage Vo is lower than the upper limit value, as in Yes in step S13, the process returns to step S11. When the voltage Vo is not less than the upper limit value like No in Step S13, the control unit 15a lowers the driving of the piezoelectric pump 21 in Step S14.
  • step S11 the drive of the piezoelectric pump 21 can be reduced until the output voltage Vo of the drive circuit 12 becomes lower than the upper limit value.
  • the method of reducing the driving of the piezoelectric pump 21 is, for example, to reduce the input voltage Vc from the power supply circuit 14 to the drive circuit 12 according to an instruction from the control unit 15a. Further, the drive duty ratio of the drive signal from the processing unit 16 to each FET may be changed. Further, the drive frequency of the drive circuit 12 may be changed.
  • the piezoelectric pump 21 can be driven with an output voltage lower than the upper limit value corresponding to the temperature upper limit. Even in this case, the piezoelectric pump 21 can be prevented from being broken.
  • the voltage detection circuit 13 may be replaced with a voltage detection circuit 13b shown in FIG.
  • the voltage detection circuit 13b includes, in addition to the resistor Rs, a capacitor Cs having one end connected to each source of the second FET 62 and the fourth FET 64 and the other end connected to ground.
  • the capacitor Cs functions as a smoothing capacitor.
  • the frequency component of the output signal from the control unit 15 may be detected as noise at both ends of the resistor Rs.
  • the detection accuracy of the output voltage Vo can be improved.
  • an amplifier circuit 67 as shown in FIG. 25 may be connected between the I / O port 66 of the control unit 15 and one end of the resistor Rs (opposite the ground side).
  • the amplifier circuit 67 includes an amplifier Q, a resistor R1, a resistor R2, and a capacitor Csa.
  • the output voltage Vo is input to the non-inverting input terminal (+) of the amplifier Q, and one end of each of the resistors R1 and R2 is connected to the inverting input terminal (-).
  • the other end of the resistor R1 is connected to the ground.
  • the other end of the resistor R2 is connected to the output terminal of the amplifier Q.
  • the output terminal of the amplifier Q is connected to the I / O port 66 of the control unit 15.
  • a capacitor Csa is connected between the inverting input terminal ( ⁇ ) of the amplifier Q and the output terminal.
  • the voltage between the resistors Rs can be amplified and rectified by the amplifier circuit 67. Thereby, the S / N ratio of the output voltage can be improved, and the detection accuracy can be improved.
  • the control unit 15 may be connected to the A / D port instead of the I / O port 66.
  • FIG. 26 is an explanatory diagram illustrating a flow of a fluid in a pressurizer using the pump device according to the fourth embodiment.
  • FIG. 27 is a circuit diagram of a drive circuit and a voltage detection circuit according to the fourth embodiment.
  • two piezoelectric pumps 21 are arranged in parallel in the pressurizer 52 of the second embodiment.
  • the nozzle 71 and the piezoelectric pump 21 are connected instead of the container 53.
  • the discharge device 52a of the fourth embodiment does not include the valve 55 unlike the second embodiment because the nozzle 71 is open to the atmosphere.
  • the pump device 11 of the fourth embodiment is common to the pump device 11 of the second embodiment.
  • the drive control of the pump device 11 of the fourth embodiment is the same as that of the third embodiment.
  • Discharger 52a using the pump device according to the fourth embodiment is used for, for example, a nebulizer.
  • the piezoelectric pump 21 By connecting the piezoelectric pump 21 in parallel with the nozzle 71, the flow rate discharged from the nozzle 71 can be increased. Furthermore, since the piezoelectric pumps 21 are electrically connected in parallel, the output voltage Vo becomes relatively large due to the voltage division ratio with the voltage detection circuit. As a result, the measurement range is expanded, so that the detection accuracy of the output voltage Vo can be improved. Note that three or more piezoelectric pumps 21 may be connected in parallel.
  • the piezoelectric pump 21 is driven at less than the upper limit, so that the piezoelectric pump 21 can be prevented from being broken even when driven at full power.
  • it is suitable for use in places with low atmospheric pressure, such as high altitudes. In the case of high altitude, a failure due to excessive amplitude of the engine is likely to occur, but this can be prevented.
  • the drive circuit 12 in FIG. 27 further includes a fifth FET 65 for preventing a voltage from being applied to the voltage detection circuit during the pump operation.
  • the gate of the fifth FET 65 is connected to the control unit 15, the drain is connected to one end of the resistor Rs, and the source is connected to ground.
  • the fifth FET 65 functions as a switching element according to the drive signal from the control unit 15.
  • the voltage detection circuit is short-circuited because the fifth FET 65 is turned on.
  • the output voltage Vo becomes 0 [V], so that the electric efficiency can be further improved.
  • the non-drive frequency band Fz is a band lower than the resonance frequency fr and higher than or equal to the anti-resonance frequency fa, but is not limited thereto.
  • the non-drive frequency band Fz may be a band below a predetermined range from the resonance frequency fr and a band above a predetermined range from the anti-resonance frequency fa.
  • the non-drive frequency band Fz may be a band having a value lower than the resonance frequency fr by 20% or less than the resonance frequency fr and a band having a value higher than the anti-resonance frequency fa by 20% or higher than the anti-resonance frequency fa.
  • the shifted non-driving frequency band Fz is included in the non-driving frequency band Fz before the shift. Characteristics can be monitored accurately.
  • the temperature in a normal use state is, for example, in a range of ⁇ 10 ° C. to + 70 ° C.
  • the input voltage input from the power supply circuit 14 when detecting the divided output voltage Vo is a lower voltage than when the piezoelectric pump 21 is driven in the drive frequency band Fw. There may be. With this configuration, power consumption when detecting the output voltage Vo of the piezoelectric pump 21 can be reduced.
  • the present invention provides a piezoelectric pump, a voltage detection unit that detects an applied voltage applied to the piezoelectric pump, and the applied voltage at a first frequency outside a driving frequency band capable of driving the piezoelectric pump. And a control unit that drives the piezoelectric pump based on the control frequency and determines a second frequency in the drive frequency band.
  • a temperature-sensitive element such as a thermistor or a thermocouple around the piezoelectric pump, or to measure the temperature inside the pump. That is, if no temperature sensing element is provided, there is no other way but to measure the temperature inside the pump. Therefore, if the temperature characteristics of the piezoelectric pump are corrected without using a temperature-sensitive element such as a thermistor, it is considered that the possibility of using the present invention is high.
  • the present invention is applicable to a pump device including a piezoelectric pump.

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Abstract

Provided is a pump device comprising a piezoelectric pump, a voltage detection unit that detects applied voltage applied to the piezoelectric pump, and a control unit that determines a second frequency within a driving frequency band that drives the piezoelectric pump on the basis of the applied voltage in a first frequency outside the driving frequency band that can drive the piezoelectric pump.

Description

ポンプ装置Pump device
　本発明は、ポンプ装置に関し、特に圧電ポンプを備えるポンプ装置に関する。 The present invention relates to a pump device, and more particularly to a pump device including a piezoelectric pump.
　従来、圧電ポンプを備えるポンプ装置が気体の吸引装置または加圧装置として用いられている。圧電ポンプは圧電素子の振動によりポンプ駆動される。 Conventionally, a pump device equipped with a piezoelectric pump has been used as a gas suction device or a pressure device. The piezoelectric pump is driven by the vibration of the piezoelectric element.
　例えば、特許文献１に記載されている圧電ポンプを用いることでポンプ装置の小型化を図ることができる。 For example, by using the piezoelectric pump described in Patent Document 1, the size of the pump device can be reduced.
　圧電素子に交流電圧を印加することで圧電素子が周期的に振動する。これにより、容器内の圧力を変化させることが出来る。この印加される交流電圧の周波数は、圧電ポンプの駆動周波数と呼ばれている。圧電ポンプの駆動周波数は、常温で予め定められている。 (4) The piezoelectric element vibrates periodically by applying an AC voltage to the piezoelectric element. Thereby, the pressure in the container can be changed. The frequency of the applied AC voltage is called a driving frequency of the piezoelectric pump. The driving frequency of the piezoelectric pump is predetermined at room temperature.
特開２０１６－５３３７１号公報JP 2016-53371 A
　しかしながら、従来のポンプ装置において、圧電ポンプの温度が常温よりも低温の状態では出力が低下し、圧電ポンプの温度が常温よりも高温になると電気効率が低下する現象が発生した。この原因として、圧電ポンプは温度特性を有することが見いだされた。そこで、圧電ポンプの温度特性を補正する手法として、水晶発振器で用いられている温度補償技術の利用が考えられる。例えば、水晶発振器では、水晶発振器の外部にサーミスタを設けて環境温度を検出し、検出温度に応じて水晶の発振周波数を補償している。 However, in the conventional pump device, when the temperature of the piezoelectric pump is lower than the normal temperature, the output decreases, and when the temperature of the piezoelectric pump becomes higher than the normal temperature, the electric efficiency decreases. As a cause, it has been found that the piezoelectric pump has a temperature characteristic. Therefore, as a technique for correcting the temperature characteristics of the piezoelectric pump, use of a temperature compensation technique used in a crystal oscillator can be considered. For example, in a crystal oscillator, a thermistor is provided outside the crystal oscillator to detect an environmental temperature, and compensate for the oscillation frequency of the crystal according to the detected temperature.
　しかしながら、圧電ポンプの場合、振動による自己発熱を原因とする温度上昇もあるので、回路基板上にサーミスタを実装して環境温度を検出するだけでは圧電ポンプの正確な温度を検出することができない。また、圧電ポンプは振動するので圧電ポンプ自身にサーミスタを取り付けることも困難である。 However, in the case of a piezoelectric pump, there is also a rise in temperature due to self-heating due to vibration. Therefore, the accurate temperature of the piezoelectric pump cannot be detected only by mounting a thermistor on a circuit board and detecting the environmental temperature. Further, since the piezoelectric pump vibrates, it is difficult to attach a thermistor to the piezoelectric pump itself.
　したがって、本発明の目的は、圧電ポンプを備えるポンプ装置において、圧電ポンプの温度に対応して圧電ポンプを駆動することができるポンプ装置を提供することにある。 Accordingly, it is an object of the present invention to provide a pump device including a piezoelectric pump, which can drive the piezoelectric pump in accordance with the temperature of the piezoelectric pump.
　上記目的を達成するために、本発明の一態様によれば、
　圧電ポンプと、
　前記圧電ポンプに印加される印加電圧を検出する電圧検出部と、
　前記圧電ポンプを駆動可能な駆動周波数帯域の帯域外の第１の周波数における前記印加電圧を基に、前記圧電ポンプを駆動する、前記駆動周波数帯域内の第２の周波数を決定する制御部と、
　を備える、ポンプ装置である。 To achieve the above object, according to one embodiment of the present invention,
A piezoelectric pump,
A voltage detection unit that detects an applied voltage applied to the piezoelectric pump,
A control unit that drives the piezoelectric pump based on the applied voltage at a first frequency outside a driving frequency band capable of driving the piezoelectric pump, and determines a second frequency within the driving frequency band,
It is a pump apparatus provided with.
　本発明に係るポンプ装置によれば、圧電ポンプを備えるポンプ装置において、圧電ポンプの温度に対応して駆動することができるポンプ装置を提供することができる。 According to the pump device of the present invention, in a pump device including a piezoelectric pump, it is possible to provide a pump device that can be driven according to the temperature of the piezoelectric pump.
圧電ポンプの模式的断面図Schematic sectional view of a piezoelectric pump 圧電ポンプの動作を示す説明図Explanatory drawing showing the operation of the piezoelectric pump 異なる温度における周波数と流量との関係を示すグラフ図Graph showing the relationship between frequency and flow rate at different temperatures 異なる温度における圧力と電気効率との関係を示すグラフ図Graph showing the relationship between pressure and electrical efficiency at different temperatures 周波数とインピーダンスとの関係を示すグラフ図Graph showing the relationship between frequency and impedance 圧電ポンプをモデル化した回路図Circuit diagram modeling a piezoelectric pump 圧電ポンプの温度と容量の変化率との関係を示すグラフ図Graph showing the relationship between the temperature of the piezoelectric pump and the rate of change of capacity 圧電ポンプの電流変化率と駆動周波数変化量との関係を示すグラフ図Graph showing the relationship between the current change rate and the drive frequency change amount of the piezoelectric pump 圧電ポンプの出力電圧と周波数補正量との関係を示すグラフ図Graph showing the relationship between the output voltage of the piezoelectric pump and the frequency correction amount 実施の形態１におけるポンプ装置のブロック図Block diagram of pump device according to Embodiment 1. 実施の形態１における吸引器の流体の流れる方向を示す説明図Explanatory drawing which shows the flow direction of the fluid of the suction device in Embodiment 1. 実施の形態１における駆動回路及び電圧検出回路の回路図Circuit diagram of drive circuit and voltage detection circuit in Embodiment 1 異なる周波数における出力電圧Ｖｏと温度との関係を示すグラフ図FIG. 6 is a graph showing the relationship between output voltage Vo and temperature at different frequencies. 実施の形態１における圧電ポンプの駆動制御の流れを示すフローチャートFlow chart showing the flow of drive control of the piezoelectric pump according to the first embodiment. 駆動制御における、時間と圧電ポンプの温度との関係の一例を示すグラフ図FIG. 4 is a graph showing an example of a relationship between time and temperature of a piezoelectric pump in drive control. 駆動制御における、時間と周波数の関係の一例を示すグラフ図FIG. 4 is a graph showing an example of a relationship between time and frequency in drive control. ポンプ装置を駆動する電池の寿命を示すグラフ図Graph showing the life of the battery driving the pump device ポンプ装置の電気効率を示すグラフ図Graph showing the electrical efficiency of the pump device 実施の形態１における駆動回路及び電圧検出回路の変形例を示す回路図5 is a circuit diagram showing a modification of the drive circuit and the voltage detection circuit according to the first embodiment. 実施の形態２における流体の流れる方向を示す説明図Explanatory diagram showing the direction in which a fluid flows in Embodiment 2. 実施の形態２におけるポンプ装置の時間と圧力との関係を示すグラフ図FIG. 6 is a graph showing a relationship between time and pressure of the pump device according to the second embodiment. 実施の形態３におけるポンプ装置のブロック図Block diagram of a pump device according to Embodiment 3. 実施の形態３における圧電ポンプの駆動制御の流れを示すフローチャートFlow chart showing the flow of drive control of the piezoelectric pump according to the third embodiment. 実施の形態３における駆動回路及び電圧検出回路の回路図Circuit diagram of drive circuit and voltage detection circuit in Embodiment 3 実施の形態３における増幅回路の回路図Circuit diagram of an amplifier circuit according to Embodiment 3. 実施の形態４における流体の流れる方向を示す説明図Explanatory drawing showing the direction in which a fluid flows in Embodiment 4. 実施の形態４における駆動回路及び電圧検出回路の回路図Circuit diagram of drive circuit and voltage detection circuit in Embodiment 4
　本発明の一態様のポンプ装置は、圧電ポンプと、前記圧電ポンプに印加される印加電圧を検出する電圧検出部と、前記圧電ポンプを駆動可能な駆動周波数帯域の帯域外の第１の周波数における前記印加電圧を基に、前記圧電ポンプを駆動する、前記駆動周波数帯域内の第２の周波数を決定する制御部と、を備える。 A pump device according to one embodiment of the present invention includes a piezoelectric pump, a voltage detection unit that detects an applied voltage applied to the piezoelectric pump, and a first frequency outside a driving frequency band capable of driving the piezoelectric pump. A control unit that drives the piezoelectric pump based on the applied voltage and determines a second frequency in the drive frequency band.
　このような構成によれば、圧電ポンプの駆動周波数帯域の帯域外の第１の周波数における圧電ポンプへの印加電圧が検出される。印加電圧の値は圧電ポンプの温度と対応しているので、この検出された印加電圧を基に、圧電ポンプを駆動する第２の周波数を決定することで、圧電ポンプの温度変化に対応した適切な周波数で圧電ポンプを駆動することができる。これにより、圧電ポンプの低温時の出力、及び高温時の電気効率を向上させることができる。 According to such a configuration, the voltage applied to the piezoelectric pump at the first frequency outside the driving frequency band of the piezoelectric pump is detected. Since the value of the applied voltage corresponds to the temperature of the piezoelectric pump, the second frequency for driving the piezoelectric pump is determined based on the detected applied voltage, so that an appropriate value corresponding to the temperature change of the piezoelectric pump can be obtained. The piezoelectric pump can be driven at an appropriate frequency. Thus, the output of the piezoelectric pump at low temperatures and the electrical efficiency at high temperatures can be improved.
　また、前記圧電ポンプと電気的に接続されるインピーダンス素子を備え、前記電圧検出部は、前記圧電ポンプと前記インピーダンス素子とにより分圧された電圧から前記印加電圧を測定してもよい。このような構成によれば、圧電ポンプの印加電圧を容易に検出することができる。 In addition, an impedance element electrically connected to the piezoelectric pump may be provided, and the voltage detection unit may measure the applied voltage from a voltage divided by the piezoelectric pump and the impedance element. According to such a configuration, the applied voltage of the piezoelectric pump can be easily detected.
　また、前記圧電ポンプに電力を供給する電力供給部を備え、前記制御部は前記電力供給部と接続され、前記圧電ポンプの出力電圧に応じて前記圧電ポンプに供給する電力を調整してもよい。このような構成によれば、圧電ポンプの出力電圧に応じて電力供給部から供給される電力を調整することができるので、圧電ポンプの過熱を防止することができる。 In addition, a power supply unit that supplies power to the piezoelectric pump may be provided, and the control unit may be connected to the power supply unit and adjust power supplied to the piezoelectric pump according to an output voltage of the piezoelectric pump. . According to such a configuration, since the power supplied from the power supply unit can be adjusted according to the output voltage of the piezoelectric pump, overheating of the piezoelectric pump can be prevented.
　また、前記制御部は、モデル化された前記圧電ポンプの容量と前記圧電ポンプの温度との関係、または、前記圧電ポンプの出力電圧と前記圧電ポンプの温度との関係を基に、前記第２の周波数を決定してもよい。 Further, the control unit may be configured to perform the second step based on a modeled relationship between the capacity of the piezoelectric pump and the temperature of the piezoelectric pump, or a relationship between the output voltage of the piezoelectric pump and the temperature of the piezoelectric pump. May be determined.
　また、前記インピーダンス素子は抵抗でもよい。 (4) The impedance element may be a resistor.
　また、前記インピーダンス素子はインダクタでもよい。 The impedance element may be an inductor.
　また、分圧された出力電圧を検出するときの入力電圧は、前記圧電ポンプを駆動周波数帯域で駆動するときよりも低い電圧であってもよい。このような構成によれば、電力の消費を低減することができる。 The input voltage when detecting the divided output voltage may be lower than when the piezoelectric pump is driven in a driving frequency band. According to such a configuration, power consumption can be reduced.
　以下、本発明に係るポンプ装置について、図面を参照しながら説明する。なお、図面において、実質的に同じ機能、構成を有する部材については同一の符号を付して、明細書においてはその説明を省略する場合がある。また、図面は理解しやすくするために、それぞれの構成要素を主体に模式的に示している。 Hereinafter, the pump device according to the present invention will be described with reference to the drawings. In the drawings, members having substantially the same function and configuration are denoted by the same reference numerals, and description thereof may be omitted in the specification. In addition, in order to facilitate understanding, the drawings schematically show each constituent element.
　なお、以下で説明する実施の形態は、いずれも本発明の一具体例を示すものであり、本発明がこの構成に限定されるものではない。また、以下の実施の形態において具体的に示される数値、形状、構成、ステップ、ステップの順序などは、一例を示すものであり、本発明を限定するものではない。以下の実施の形態における構成要素のうち、最上位概念を示す独立請求項に記載されていない構成要素については、任意の構成要素として説明される。また、全ての実施の形態において、各変形例における構成も同様であり、各変形例に記載した構成をそれぞれ組み合わせてもよい。 Note that each of the embodiments described below shows a specific example of the present invention, and the present invention is not limited to this configuration. Further, numerical values, shapes, configurations, steps, order of steps, and the like specifically shown in the following embodiments are merely examples, and do not limit the present invention. Among the components in the following embodiments, components not described in the independent claims indicating the highest concept are described as arbitrary components. In all the embodiments, the configuration in each modification is the same, and the configuration described in each modification may be combined.
（圧電ポンプの温度特性）
　最初に、圧電ポンプの温度特性について図１から図９を参照して説明する。まず、図１及び図２を参照して圧電ポンプの構造について説明する。図１は、圧電ポンプの模式的断面図である。図２は、圧電ポンプの動作を示す説明図である。 (Temperature characteristics of piezoelectric pump)
First, the temperature characteristics of the piezoelectric pump will be described with reference to FIGS. First, the structure of the piezoelectric pump will be described with reference to FIGS. FIG. 1 is a schematic sectional view of a piezoelectric pump. FIG. 2 is an explanatory diagram showing the operation of the piezoelectric pump.
　１．圧電ポンプ
　圧電ポンプ２１は、カバー板２２、流路板２３、対向板２４、接着層２５、振動板２６、圧電素子２７、絶縁板２８、給電板２９、スペーサ板３０及び蓋板３１をこの順に積層してなる。圧電ポンプ２１は、積層方向に薄く、平面視で（積層方向から見て）矩形状になっている。圧電ポンプ２１のカバー板２２側には、吸引口３３が形成されている。圧電ポンプ２１の蓋板３１側には、吐出口３４が形成されている。 1. Piezoelectric Pump The piezoelectric pump 21 includes a cover plate 22, a channel plate 23, an opposing plate 24, an adhesive layer 25, a vibration plate 26, a piezoelectric element 27, an insulating plate 28, a power supply plate 29, a spacer plate 30, and a cover plate 31 in this order. Laminated. The piezoelectric pump 21 is thin in the stacking direction and has a rectangular shape in a plan view (as viewed from the stacking direction). A suction port 33 is formed on the cover plate 22 side of the piezoelectric pump 21. A discharge port 34 is formed on the lid plate 31 side of the piezoelectric pump 21.
　カバー板２２には、円形状の流路孔３７が形成されている。流路板２３には、円形状の開口部３８が形成されている。開口部３８は流路孔３７に連通している。開口部３８の径は流路孔３７の径より大きくなっている。対向板２４は金属製である。対向板２４には、外側に突出する外部接続端子３５、及び、円形状の吸引口３３が形成されている。吸引口３３は開口部３８に連通している。吸引口３３の径は開口部３８の径より小さくなっている。これにより、対向板２４の吸引口３３の周囲には、屈曲可能な可動部３９が形成される。 円 A circular channel hole 37 is formed in the cover plate 22. The channel plate 23 has a circular opening 38 formed therein. The opening 38 communicates with the channel hole 37. The diameter of the opening 38 is larger than the diameter of the flow path hole 37. The opposing plate 24 is made of metal. An external connection terminal 35 protruding outward and a circular suction port 33 are formed in the facing plate 24. The suction port 33 communicates with the opening 38. The diameter of the suction port 33 is smaller than the diameter of the opening 38. Thereby, a bendable movable portion 39 is formed around the suction port 33 of the opposing plate 24.
　接着層２５は、振動板２６の枠部４４と重なるように枠状に形成されている。接着層２５は、エポキシ樹脂などの熱硬化性樹脂に、粒径が略均一な複数の導電性粒子を含有してなる。これにより、対向板２４と振動板２６とを接着層２５の導電性粒子を介して電気的に導通させることができる。 The adhesive layer 25 is formed in a frame shape so as to overlap the frame portion 44 of the diaphragm 26. The adhesive layer 25 is composed of a thermosetting resin such as an epoxy resin and contains a plurality of conductive particles having a substantially uniform particle size. Thereby, the opposing plate 24 and the vibration plate 26 can be electrically conducted through the conductive particles of the adhesive layer 25.
　振動板２６は、例えば、ＳＵＳ３０１のような金属製である。振動板２６は、一定の間隔だけ離れて対向板２４と対向している。対向板２４と振動板２６との隙間はポンプ室４０を構成している。振動板２６は、中央部４１、打撃部４２、連結部４３及び枠部４４を有する。中央部４１は、平面視で円形状であり、振動板２６の中央に配置されている。枠部４４は、平面視で枠状であり、振動板２６の周囲に配置されている。連結部４３は、梁状であり、中央部４１と枠部４４とを連結する。打撃部４２は、平面視で円形状であり、中央部４１と連結部４３との境界付近に配置されている。打撃部４２は、その中心が吸引口３３と対向するように配置されている。打撃部４２の径は吸引口３３の径より大きくなっている。打撃部４２及び枠部４４は中央部４１及び連結部４３より厚くなっている。振動板２６には、上述の振動板２６の構成部分で囲まれる開口部（図示せず）が形成されている。ポンプ室４０はこの開口部を介してポンプ室４６に連通している。 The diaphragm 26 is made of metal such as SUS301, for example. The vibration plate 26 faces the opposing plate 24 at a predetermined interval. The gap between the opposing plate 24 and the diaphragm 26 constitutes a pump chamber 40. The diaphragm 26 has a central portion 41, a hitting portion 42, a connecting portion 43, and a frame portion 44. The central portion 41 has a circular shape in plan view, and is disposed at the center of the diaphragm 26. The frame portion 44 has a frame shape in a plan view, and is arranged around the diaphragm 26. The connecting portion 43 has a beam shape and connects the central portion 41 and the frame portion 44. The hitting portion 42 has a circular shape in plan view, and is disposed near a boundary between the central portion 41 and the connecting portion 43. The striking section 42 is arranged such that the center thereof faces the suction port 33. The diameter of the hitting portion 42 is larger than the diameter of the suction port 33. The hitting portion 42 and the frame portion 44 are thicker than the central portion 41 and the connecting portion 43. The diaphragm 26 has an opening (not shown) surrounded by the components of the diaphragm 26 described above. The pump chamber 40 communicates with the pump chamber 46 through the opening.
　圧電素子２７は、圧電材料からなる薄板の両主面に電極を設けて構成されている。圧電素子２７は、厚み方向に電界が印加されることにより、面内方向に面積が拡大または縮小するような圧電性を有している。圧電素子２７は、円板状であり、振動板２６の中央部４１の上面に貼り付けられている。圧電素子２７の下面の電極は、振動板２６、接着層２５及び対向板２４を介して、外部接続端子３５に電気的に接続されている。 The piezoelectric element 27 is configured by providing electrodes on both main surfaces of a thin plate made of a piezoelectric material. The piezoelectric element 27 has such a piezoelectric property that its area increases or decreases in the in-plane direction when an electric field is applied in the thickness direction. The piezoelectric element 27 has a disk shape and is attached to the upper surface of the central portion 41 of the diaphragm 26. The electrode on the lower surface of the piezoelectric element 27 is electrically connected to the external connection terminal 35 via the vibration plate 26, the adhesive layer 25, and the opposing plate 24.
　絶縁板２８は絶縁性樹脂からなる。絶縁板２８には、平面視で矩形状の開口部が形成されている。給電板２９は金属製である。給電板２９には、平面視で矩形状の開口部、給電板２９の開口部に突出する内部接続端子４５、及び、外側に突出する外部接続端子３６が形成されている。内部接続端子４５の先端は圧電素子２７の上面の電極にはんだ付けされている。スペーサ板３０は樹脂製である。スペーサ板３０には、平面視で矩形状の開口部が形成されている。絶縁板２８、給電板２９及びスペーサ板３０の開口部は、互いに連通することでポンプ室４６を構成している。蓋板３１には、平面視で円形状の吐出口３４が形成されている。吐出口３４はポンプ室４６及び外部に連通している。 The insulating plate 28 is made of an insulating resin. The insulating plate 28 has a rectangular opening in a plan view. The power supply plate 29 is made of metal. The power supply plate 29 is formed with a rectangular opening in plan view, an internal connection terminal 45 protruding from the opening of the power supply plate 29, and an external connection terminal 36 protruding outward. The tip of the internal connection terminal 45 is soldered to an electrode on the upper surface of the piezoelectric element 27. The spacer plate 30 is made of resin. The spacer plate 30 is formed with a rectangular opening in plan view. The openings of the insulating plate 28, the power supply plate 29, and the spacer plate 30 communicate with each other to form a pump chamber 46. The cover plate 31 is formed with a circular discharge port 34 in plan view. The discharge port 34 communicates with the pump chamber 46 and the outside.
　図２は、圧電ポンプ２１の動作を示す模式図である。圧電ポンプ２１では、外部接続端子３５、３６に交流の駆動電圧が印加されると、圧電素子２７が面内方向に等方的に伸縮しようとして、圧電素子２７と振動板２６との積層体に厚み方向の屈曲振動が同心円状に生じる。この屈曲振動は、高次の共振モードであり、枠部４４が固定部となり、中央部４１の中心が第１の振動の腹となり、打撃部４２の中心が第２の振動の腹となる。 FIG. 2 is a schematic diagram showing the operation of the piezoelectric pump 21. In the piezoelectric pump 21, when an AC drive voltage is applied to the external connection terminals 35 and 36, the piezoelectric element 27 tries to expand and contract isotropically in the in-plane direction, and the piezoelectric element 27 and the vibration plate 26 are stacked. Flexural vibration in the thickness direction occurs concentrically. This bending vibration is a higher-order resonance mode, in which the frame portion 44 becomes a fixed portion, the center of the central portion 41 becomes an antinode of the first vibration, and the center of the hitting portion 42 becomes an antinode of the second vibration.
　打撃部４２の振動は、打撃部４２に対向する流体を介して可動部３９に伝達される。打撃部４２の振動と可動部３９の振動とが連成されることにより、ポンプ室４０において吸引口３３の近傍から可動部３９の外周側に流体が流れるようになる。これにより、ポンプ室４０において吸引口３３の周辺に負圧が生じて、吸引口３３からポンプ室４６に流体が吸引される。また、ポンプ室４６の内部に正圧が生じ、この正圧が蓋板３１の吐出口３４で開放される。したがって、吸引口３３を介してポンプ室４０、４６に吸引された流体は、吐出口３４を介してポンプ室４０、４６から流出する。 振動 The vibration of the striking section 42 is transmitted to the movable section 39 via the fluid facing the striking section 42. Fluid flows from the vicinity of the suction port 33 in the pump chamber 40 to the outer peripheral side of the movable portion 39 by coupling the vibration of the impact portion 42 and the vibration of the movable portion 39. As a result, a negative pressure is generated around the suction port 33 in the pump chamber 40, and the fluid is sucked from the suction port 33 into the pump chamber 46. Further, a positive pressure is generated inside the pump chamber 46, and the positive pressure is released at the discharge port 34 of the cover plate 31. Therefore, the fluid sucked into the pump chambers 40 and 46 via the suction port 33 flows out of the pump chambers 40 and 46 via the discharge port 34.
　なお、圧電ポンプ２１の圧電素子２７、振動板２６、及び対向板２４はエンジンと呼ばれる。圧電ポンプ２１が駆動する状態とは、圧電ポンプ２１のエンジンが屈曲振動する状態である。言い換えると、圧電ポンプ２１が駆動している状態とは、圧電ポンプ２１へ流体が吸引または圧電ポンプ２１から流体が吐出されている状態をいう。また、この反対に、圧電ポンプ２１が駆動していない非駆動の状態とは、圧電ポンプ２１へ流体が吸引されていない状態、または、圧電ポンプ２１から流体が吐出されていない状態である。 The piezoelectric element 27, the diaphragm 26, and the opposing plate 24 of the piezoelectric pump 21 are called an engine. The state in which the piezoelectric pump 21 is driven is a state in which the engine of the piezoelectric pump 21 bends and vibrates. In other words, the state in which the piezoelectric pump 21 is driven refers to a state in which a fluid is sucked into the piezoelectric pump 21 or a fluid is discharged from the piezoelectric pump 21. On the other hand, the non-driven state in which the piezoelectric pump 21 is not driven is a state in which fluid is not sucked into the piezoelectric pump 21 or a state in which fluid is not discharged from the piezoelectric pump 21.
　２．圧電ポンプの温度特性
　上述した圧電ポンプ２１は、温度に応じて最適な駆動周波数が変化することが新たに見いだされた。図３は、異なる温度における圧力と電気効率との関係を示すグラフ図である。図３は、圧電ポンプ２１の背圧が３８０ｍｍＨｇの状況において、グラフＧａは圧電ポンプ２１が４０℃のときの、グラフＧｂは２３℃のときの、グラフＧｃは１０℃のときの、それぞれの駆動周波数と空気の流量との関係を示している。 2. Temperature Characteristics of Piezoelectric Pump It has been newly found that the above-described piezoelectric pump 21 changes the optimum driving frequency in accordance with the temperature. FIG. 3 is a graph showing the relationship between pressure and electrical efficiency at different temperatures. FIG. 3 shows the driving when the piezoelectric pump 21 is at 40 ° C., the graph Gb is at 23 ° C., and the graph Gc is at 10 ° C. when the back pressure of the piezoelectric pump 21 is 380 mmHg. The relationship between frequency and air flow is shown.
　グラフＧａの最適駆動周波数Ｆｇａと、グラフＧｂの最適駆動周波数Ｆｇｂと、グラフＧｃの最適駆動周波数Ｆｇｃはそれぞれ異なる。したがって、駆動周波数が２３℃のときに最適に駆動するようにＦｇｂで設定されている場合、１０℃の環境温度下では、圧電ポンプ２１は、背圧３８０ｍｍＨｇにおいて流量がゼロになるので、ポンプとして動作しない。このように、常温から低温になるとポンプ出力が低下する。 最適 The optimum driving frequency Fga of the graph Ga, the optimum driving frequency Fgb of the graph Gb, and the optimum driving frequency Fgc of the graph Gc are different from each other. Therefore, when the drive frequency is set to Fgb so as to drive optimally when the drive frequency is 23 ° C., at an environment temperature of 10 ° C., the flow rate of the piezoelectric pump 21 becomes zero at a back pressure of 380 mmHg. Do not work. As described above, the pump output decreases when the temperature decreases from room temperature.
　図４は、異なる温度における圧力と電気効率との関係を示すグラフ図である。図４は、図３の周波数Ｆｇｂで駆動した時の各温度での電気効率を示す。グラフＧｄは圧電ポンプ２１が５０℃のときの、グラフＧｈは２５℃のときの、グラフＧｅは０℃のときの、それぞれの圧力と電気効率との関係を示している。 FIG. 4 is a graph showing the relationship between pressure and electrical efficiency at different temperatures. FIG. 4 shows the electrical efficiency at each temperature when driven at the frequency Fgb of FIG. The graph Gd shows the relationship between the respective pressures and the electrical efficiency when the piezoelectric pump 21 is at 50 ° C., the graph Gh at 25 ° C., and the graph Ge at 0 ° C.
　図４に示すように、温度によって電気効率のピーク値が異なり、特に高温で電気効率が低下している。電気効率が悪いと、例えば電源に電池を使用した場合、電池の寿命が短くなり、電池交換や充電頻度が増えるのでユーザビリティ－が低下する。 (4) As shown in FIG. 4, the peak value of the electric efficiency varies depending on the temperature, and the electric efficiency decreases particularly at a high temperature. If the electric efficiency is poor, for example, when a battery is used as a power supply, the life of the battery is shortened, and the frequency of battery replacement and charging is increased, thereby reducing usability.
　圧電ポンプ２１の周波数特性について図５を参照してさらに説明する。図５は、常温、例えば、２０℃における駆動周波数とインピーダンスとの関係を示すグラフ図である。圧電ポンプ２１の周波数特性は、共振周波数ｆｒと***振周波数ｆａを有する。共振周波数ｆｒは約２３．４ｋＨｚであり、***振周波数ｆａは約２４．５ｋＨｚである。この共振周波数ｆｒと***振周波数ｆａとの間が圧電ポンプを駆動することができる駆動周波数帯域Ｆｗである。また、共振周波数ｆｒ未満の周波数帯域と***振周波数ｆａ以上の周波数帯域は非駆動周波数帯域Ｆｚである。 (5) The frequency characteristic of the piezoelectric pump 21 will be further described with reference to FIG. FIG. 5 is a graph showing the relationship between the driving frequency and the impedance at normal temperature, for example, 20 ° C. The frequency characteristic of the piezoelectric pump 21 has a resonance frequency fr and an anti-resonance frequency fa. The resonance frequency fr is about 23.4 kHz, and the anti-resonance frequency fa is about 24.5 kHz. A driving frequency band Fw in which the piezoelectric pump can be driven is between the resonance frequency fr and the anti-resonance frequency fa. The frequency band lower than the resonance frequency fr and the frequency band higher than the anti-resonance frequency fa are non-drive frequency bands Fz.
　この周波数特性の関係は温度に応じてシフトする。温度が低下すれば駆動周波数帯域は周波数の高い方へシフトし、温度が上昇すれば駆動周波数帯域は周波数の低い方へシフトする。 関係 The relationship of this frequency characteristic shifts according to the temperature. When the temperature decreases, the driving frequency band shifts to a higher frequency, and when the temperature increases, the driving frequency band shifts to a lower frequency.
　このような周波数特性を有する圧電ポンプ２１は、ＬＣＲの電気回路にモデル化することができる。図６は、圧電ポンプ２１をモデル化した等価回路図である。非駆動周波数帯域Ｆｚは容量Ｃａの周波数特性を有する。共振周波数ｆｒは、インダクタＬ、容量Ｃｂ及び抵抗Ｒの直列回路Ｄａの周波数特性を有する。***振周波数ｆａは、ＬＣＲ直列回路Ｄａと容量Ｃとの並列回路Ｄｂの周波数特性を有する。 圧 電 The piezoelectric pump 21 having such frequency characteristics can be modeled as an LCR electric circuit. FIG. 6 is an equivalent circuit diagram modeling the piezoelectric pump 21. The non-drive frequency band Fz has a frequency characteristic of the capacitor Ca. The resonance frequency fr has a frequency characteristic of a series circuit Da including the inductor L, the capacitor Cb, and the resistor R. The anti-resonance frequency fa has a frequency characteristic of a parallel circuit Db including the LCR series circuit Da and the capacitor C.
　図５を再び参照する。例えば、６０ｋＨｚのような非駆動周波数において、インピーダンスは、圧電ポンプ２１の容量Ｃａのみによって決まるので、入力電圧や背圧に対して比較的に安定で、温度に敏感に反応する。非駆動周波数が含まれる非駆動周波数帯域とは、例えばインピーダンスが極小となる共振周波数と極大となる***振周波数との間を除く（言い換えるとインピーダンスがＣ性である）周波数領域である。 再 び Refer again to FIG. For example, at a non-driving frequency such as 60 kHz, the impedance is determined only by the capacitance Ca of the piezoelectric pump 21, so that the impedance is relatively stable with respect to an input voltage or a back pressure and is sensitive to temperature. The non-drive frequency band including the non-drive frequency is, for example, a frequency region excluding a region between a resonance frequency at which the impedance is minimum and an anti-resonance frequency at which the impedance is maximum (in other words, the impedance is C-characteristic).
　図７を参照する。図７は、圧電ポンプの温度と容量の変化率との関係を示すグラフ図である。図７は、非駆動周波数における容量と温度との関係を示している。図７に示すように、温度変化に対応して圧電ポンプ２１の容量が変化していることが理解できる。常温での容量Ｃａは圧電ポンプ２１の誘電率や厚み、面積により決定されるが、その誤差は小さい。したがって、圧電ポンプ２１の非駆動周波数における容量Ｃａがわかれば温度を精度よく検出することができる。容量Ｃと圧電ポンプ２１のインピーダンスＺとは逆数の関係にある。インピーダンスＺと周波数ｆ及び容量Ｃとの関係は以下の式で表される。 参照 Refer to FIG. FIG. 7 is a graph showing the relationship between the temperature of the piezoelectric pump and the rate of change of the capacity. FIG. 7 shows the relationship between the capacitance and the temperature at the non-drive frequency. As shown in FIG. 7, it can be understood that the capacity of the piezoelectric pump 21 changes according to the temperature change. The capacity Ca at normal temperature is determined by the dielectric constant, thickness, and area of the piezoelectric pump 21, but the error is small. Therefore, if the capacitance Ca at the non-drive frequency of the piezoelectric pump 21 is known, the temperature can be accurately detected. The capacity C and the impedance Z of the piezoelectric pump 21 have a reciprocal relationship. The relationship between the impedance Z, the frequency f, and the capacitance C is represented by the following equation.
　Ｚ＝１／２（２×π×ｆ×Ｃ）　・・・（１）式 {Z = 1/2 (2 × π × f × C)} (1)
　入力電圧Ｖｃが一定のときに、インピーダンスＺが決まると、オームの法則Ｖ＝ＺＩにより、圧電ポンプ２１に流れる電流値が決定される。一方、各温度での最適な駆動周波数は、圧電ポンプ２１の設計により定まるので、電流値が決まれば、図８のような電流値と最適駆動周波数との関係から最適周波数が決定される。このような圧電ポンプ２１に流れる電流値と最適駆動周波数との関係をテーブルまたは数式として記憶しておくことで、検出された電流ごとに最適な駆動周波数を決定することが可能である。すなわち、圧電ポンプ２１の温度変化に応じて駆動周波数を決定している。このことは、非駆動周波数における圧電ポンプ２１のインピーダンス変化に応じて圧電ポンプ２１の駆動周波数を決定することに対応している。 When the impedance Z is determined when the input voltage Vc is constant, the value of the current flowing through the piezoelectric pump 21 is determined according to Ohm's law V = ZI. On the other hand, the optimum drive frequency at each temperature is determined by the design of the piezoelectric pump 21, and if the current value is determined, the optimum frequency is determined from the relationship between the current value and the optimum drive frequency as shown in FIG. By storing the relationship between the current value flowing through the piezoelectric pump 21 and the optimal driving frequency as a table or a mathematical expression, it is possible to determine the optimal driving frequency for each detected current. That is, the drive frequency is determined according to the temperature change of the piezoelectric pump 21. This corresponds to determining the drive frequency of the piezoelectric pump 21 according to the impedance change of the piezoelectric pump 21 at the non-drive frequency.
　また、圧電ポンプ２１に流れる電流値を検出するよりも、圧電ポンプ２１の出力電圧を検出する方が容易である。そこで、電流値の代わりに出力電圧に応じて駆動周波数を変化させてもよい。図９は、圧電ポンプの出力電圧と駆動周波数補正量との関係を示すグラフ図である。出力電圧は圧電ポンプの温度に対応して変化するパラメータである。したがって、出力電圧に応じて駆動周波数を補正することで、温度変化に対応して圧電ポンプ２１を適切に駆動することができる。出力電圧が高いほど圧電ポンプ２１の温度は高いので、駆動周波数を低く補正する。 (4) It is easier to detect the output voltage of the piezoelectric pump 21 than to detect the value of the current flowing through the piezoelectric pump 21. Therefore, the driving frequency may be changed according to the output voltage instead of the current value. FIG. 9 is a graph showing the relationship between the output voltage of the piezoelectric pump and the drive frequency correction amount. The output voltage is a parameter that changes according to the temperature of the piezoelectric pump. Therefore, by correcting the drive frequency according to the output voltage, it is possible to appropriately drive the piezoelectric pump 21 in response to a temperature change. Since the temperature of the piezoelectric pump 21 is higher as the output voltage is higher, the drive frequency is corrected to be lower.
（実施の形態１）
　以下に、本発明の実施の形態１にかかるポンプ装置について説明する。図１０は、実施の形態１におけるポンプ装置を示すブロック図である。 (Embodiment 1)
Hereinafter, the pump device according to the first embodiment of the present invention will be described. FIG. 10 is a block diagram showing a pump device according to the first embodiment.
　ポンプ装置１１は、圧電ポンプ２１と、圧電ポンプ２１を駆動する駆動回路１２と、圧電ポンプ２１の出力電圧を検出する電圧検出回路１３と、駆動回路１２に電力を供給する電源回路１４と、圧電ポンプ２１の駆動周波数を決定する制御部１５とを備える。 The pump device 11 includes a piezoelectric pump 21, a drive circuit 12 for driving the piezoelectric pump 21, a voltage detection circuit 13 for detecting an output voltage of the piezoelectric pump 21, a power supply circuit 14 for supplying power to the drive circuit 12, A control unit for determining a drive frequency of the pump;
　制御部１５は、処理部１６と、記憶部１７とを有する。制御部１５は、例えば、処理部１６と記憶部１７が一体化されたＭＣＵ（Micro Control Unit）でもよいし、それぞれ個別に備える形態でもよい。個別の場合、処理部１６は、ＣＰＵ、マイクロチップまたはＦＰＧＡでもよい。記憶部１７は、メモリ、ハードディスク、またはＳＳＤでもよい。なお、実施の形態１では、制御部１５としてＭＣＵを採用した場合を一例として説明する。記憶部１７には、出力電圧Ｖｏと駆動周波数ｆｏとの関係が、関係式またはテーブルとして記憶されている。この出力電圧Ｖｏと駆動周波数ｆｏとの関係は、モデル化された圧電ポンプ２１の容量Ｃと圧電ポンプ２１の温度との関係、または、出力電圧Ｖｏと圧電ポンプ２１の温度との関係から予め算出しておくことで、処理時間の短縮化をしている。 The control unit 15 includes a processing unit 16 and a storage unit 17. The control unit 15 may be, for example, an MCU (Micro Control Unit) in which the processing unit 16 and the storage unit 17 are integrated, or may be provided separately. In the individual case, the processing unit 16 may be a CPU, a microchip, or an FPGA. The storage unit 17 may be a memory, a hard disk, or an SSD. In the first embodiment, a case where an MCU is employed as the control unit 15 will be described as an example. The relationship between the output voltage Vo and the drive frequency fo is stored in the storage unit 17 as a relational expression or a table. The relationship between the output voltage Vo and the driving frequency fo is calculated in advance from the modeled relationship between the capacity C of the piezoelectric pump 21 and the temperature of the piezoelectric pump 21 or the relationship between the output voltage Vo and the temperature of the piezoelectric pump 21. By doing so, the processing time is shortened.
　実施の形態１のポンプ装置１１は、例えば、図１１に示されるような吸引器５１に用いられる。図１１は、実施の形態１における吸引器の流体の流れを説明する説明図である。実施の形態１では、吸引器５１の中でも、例えば、搾乳機を例として説明する。吸引器５１は、流体が貯め込まれた容器５３と、容器５３から流体を吸引する圧電ポンプ２１と、バルブ５５と、容器５３、バルブ５５、及び、圧電ポンプ２１とを接続するチューブ５７とを備える。流体は、液体又は気体のどちらでもよい。吸引器の具体例として、搾乳機、ＮＰＷＴ（Negative pressure wound therapy）、ドレナージ、鼻水吸引器が挙げられる。図１１には、１つの圧電ポンプ２１が容器５３に接続されているが、２つ以上の圧電ポンプ２１が容器５３に直列に接続されていてもよい。 The pump device 11 according to the first embodiment is used, for example, in a suction device 51 as shown in FIG. FIG. 11 is an explanatory diagram illustrating the flow of the fluid in the suction device according to the first embodiment. In the first embodiment, among the suction devices 51, for example, a milking machine will be described as an example. The suction device 51 includes a container 53 in which a fluid is stored, a piezoelectric pump 21 that sucks the fluid from the container 53, a valve 55, and a tube 57 that connects the container 53, the valve 55, and the piezoelectric pump 21. Prepare. The fluid may be a liquid or a gas. Specific examples of the suction device include a milking machine, NPWT (Negative Pressure Wound Therapy), drainage, and a runny suction device. In FIG. 11, one piezoelectric pump 21 is connected to the container 53, but two or more piezoelectric pumps 21 may be connected to the container 53 in series.
　図１２を参照して、駆動回路１２を説明する。図１２は、駆動回路１２及び電圧検出回路１３の回路図である。駆動回路１２は、例えば、Ｈブリッジ回路である。駆動回路１２は第１ＦＥＴ６１、第２ＦＥＴ６２、第３ＦＥＴ６３、及び第４ＦＥＴ６４の４つのＦＥＴを有する。制御部１５から第１ＦＥＴ６１～第４ＦＥＴ６４への駆動信号により、各ＦＥＴがスイッチング駆動され、圧電ポンプ２１へ予め定められた周波数の交流電圧が印加される。 駆 動 The drive circuit 12 will be described with reference to FIG. FIG. 12 is a circuit diagram of the drive circuit 12 and the voltage detection circuit 13. The drive circuit 12 is, for example, an H-bridge circuit. The drive circuit 12 has four FETs, a first FET 61, a second FET 62, a third FET 63, and a fourth FET 64. Each of the FETs is switched by a drive signal from the control unit 15 to the first to fourth FETs 61 to 64, and an AC voltage having a predetermined frequency is applied to the piezoelectric pump 21.
　第１ＦＥＴ６１及び第３ＦＥＴ６３のドレインに電源回路１４から入力電圧Ｖｃが印加される。第１ＦＥＴ６１のソースは、第２ＦＥＴ６２のドレイン及び圧電ポンプ２１の外部接続端子３５と接続される。第３ＦＥＴ６３のソースは、第４ＦＥＴ６４のドレイン及び圧電ポンプ２１の外部接続端子３６と接続される。第２ＦＥＴ６２のソース及び第４ＦＥＴ６４のソースとは、電圧検出回路１３に接続される。電圧検出回路１３は、圧電ポンプ２１と電気的に接続されるインピーダンス素子を備える。インピーダンス素子として、例えば、抵抗器Ｒｓを用いる。 (4) The input voltage Vc is applied from the power supply circuit 14 to the drains of the first FET 61 and the third FET 63. The source of the first FET 61 is connected to the drain of the second FET 62 and the external connection terminal 35 of the piezoelectric pump 21. The source of the third FET 63 is connected to the drain of the fourth FET 64 and the external connection terminal 36 of the piezoelectric pump 21. The source of the second FET 62 and the source of the fourth FET 64 are connected to the voltage detection circuit 13. The voltage detection circuit 13 includes an impedance element that is electrically connected to the piezoelectric pump 21. As the impedance element, for example, a resistor Rs is used.
　電力供給部としての電源回路１４から供給される直流の入力電圧Ｖｃは、第１ＦＥＴ６１、圧電ポンプ２１、第４ＦＥＴ６４及び抵抗器Ｒｓにより分圧されるか、第３ＦＥＴ６３、圧電ポンプ２１、第２ＦＥＴ６２により分圧される。ここで、第１ＦＥＴ６１～第４ＦＥＴ６４での電圧降下は無視できるほど小さい。したがって、圧電ポンプ２１と抵抗器Ｒｓとの分圧により出力電圧Ｖｏが決まる。図１３は、異なる周波数における出力電圧Ｖｏと温度との関係を示している。グラフＧｓは第１の周波数である非駆動周波数帯域Ｆｚ内の非駆動周波数ｆ１が１５ｋＨｚの場合であり、グラフＧｔは非駆動周波数ｆ１が３２ｋＨｚの場合であり、グラフＧｖは非駆動周波数ｆ１が４５ｋＨｚの場合であり、グラフＧｗは非駆動周波数ｆ１が６０ｋＨｚの場合の出力電圧Ｖｏと温度との関係を示す。出力電圧Ｖｏを制御部１５で読み取ることで圧電ポンプ２１の温度を測定することができる。 The DC input voltage Vc supplied from the power supply circuit 14 as a power supply unit is divided by the first FET 61, the piezoelectric pump 21, the fourth FET 64, and the resistor Rs, or divided by the third FET 63, the piezoelectric pump 21, and the second FET 62. Pressed. Here, the voltage drop in the first to fourth FETs 61 to 64 is negligibly small. Therefore, the output voltage Vo is determined by the partial pressure between the piezoelectric pump 21 and the resistor Rs. FIG. 13 shows the relationship between the output voltage Vo and the temperature at different frequencies. The graph Gs shows the case where the non-driving frequency f1 in the non-driving frequency band Fz which is the first frequency is 15 kHz, the graph Gt shows the case where the non-driving frequency f1 is 32 kHz, and the graph Gv shows the case where the non-driving frequency f1 is 45 kHz. And the graph Gw shows the relationship between the output voltage Vo and the temperature when the non-drive frequency f1 is 60 kHz. The temperature of the piezoelectric pump 21 can be measured by reading the output voltage Vo by the control unit 15.
　電圧検出回路１３は、例えば、抵抗器Ｒｓである。抵抗器Ｒｓ間の電圧を検出することで、駆動回路１２の出力電圧Ｖｏを検出することができる。入力電圧Ｖｃと出力電圧Ｖｏとの差が圧電ポンプ２１の印加電圧（駆動電圧）となる。このように、本明細書における印加電圧とは、駆動回路１２へ入力される入力電圧と駆動回路１２から出力される出力電圧との差の電圧のことである。入力電圧Ｖｃは制御部１５からの指示にしたがった電圧値で電源回路１４から供給されるので、出力電圧Ｖｏの変動は圧電ポンプ２１の印加電圧と対応している。したがって、圧電ポンプ２１の印加電圧を検出することは、出力電圧Ｖｏを検出することで代用できる。抵抗器Ｒｓの一端側は、制御部１５のＩ／Ｏポート６６に接続されているので、出力電圧Ｖｏが制御部１５によって読み取られる。本願発明の電圧検出部は、電圧検出回路１３と制御部１５とで構成される。また、制御部１５は本願発明の制御部にも相当する。 The voltage detection circuit 13 is, for example, a resistor Rs. The output voltage Vo of the drive circuit 12 can be detected by detecting the voltage between the resistors Rs. The difference between the input voltage Vc and the output voltage Vo is the applied voltage (drive voltage) of the piezoelectric pump 21. As described above, the applied voltage in this specification is a voltage that is a difference between the input voltage input to the drive circuit 12 and the output voltage output from the drive circuit 12. Since the input voltage Vc is supplied from the power supply circuit 14 at a voltage value according to an instruction from the control unit 15, the fluctuation of the output voltage Vo corresponds to the applied voltage of the piezoelectric pump 21. Therefore, detecting the applied voltage of the piezoelectric pump 21 can be substituted by detecting the output voltage Vo. Since one end of the resistor Rs is connected to the I / O port 66 of the control unit 15, the output voltage Vo is read by the control unit 15. The voltage detection unit of the present invention includes a voltage detection circuit 13 and a control unit 15. The control unit 15 also corresponds to the control unit of the present invention.
　また、駆動周波数ｆｏを決定するための非駆動周波数ｆ１は、圧電ポンプ２１のインピーダンスＺが低いので、周波数が高い方がよい。例えば、以下の関係式を満たす方がよい。
　ｆ１＞１．２×ｆｏ　・・・（２）式 Further, the non-drive frequency f1 for determining the drive frequency fo is preferably higher because the impedance Z of the piezoelectric pump 21 is lower. For example, it is better to satisfy the following relational expression.
f1> 1.2 × fo Expression (2)
　次に、ポンプ装置１１の駆動制御について、図１４～図１８を参照して説明する。図１４はポンプ装置１１の駆動制御の流れを示すフローチャートである。図１５は、駆動制御における、時間と圧電ポンプの温度との関係の一例を示すグラフ図である。図１６は、駆動制御における、時間と周波数の関係の一例を示すグラフ図である。図１５に示すように、圧電ポンプ２１の駆動により時間と共に、圧電ポンプの温度は上昇する。この圧電ポンプ２１の上昇に対して、図１６に示すように、圧電ポンプに印加する電圧の周波数を変化させる。 Next, the drive control of the pump device 11 will be described with reference to FIGS. FIG. 14 is a flowchart showing the flow of drive control of the pump device 11. FIG. 15 is a graph showing an example of the relationship between time and the temperature of the piezoelectric pump in drive control. FIG. 16 is a graph showing an example of the relationship between time and frequency in drive control. As shown in FIG. 15, the temperature of the piezoelectric pump increases with time by driving the piezoelectric pump 21. In response to the rise of the piezoelectric pump 21, the frequency of the voltage applied to the piezoelectric pump is changed as shown in FIG.
　ステップＳ１において、駆動回路１２は、制御部１５の処理部１６からの指示にしたがって、時間ｔ１から時間ｔ２の間に非駆動周波数帯域Ｆｚ内の非駆動周波数ｆｚ１で圧電ポンプ２１に電圧を印加する。時間ｔ１－ｔ２間は、例えば、３０ｍｓｅｃである。時間ｔ１－ｔ２間において、圧電ポンプ２１は、非駆動周波数ｆｚ１の電圧が印加されているので、ポンプ動作をしない。しかしながら、圧電ポンプ２１及び電圧検出回路１３に電流が流れる。ステップＳ２において、制御部１５は、電圧検出回路１３に分圧された電圧Ｖｏを検出する。この場合、電圧Ｖｏは圧電ポンプ２１に印加される印加電圧である。ステップＳ３において、処理部１６は、検出された電圧Ｖｏを記憶部１７に記憶されているテーブルに照合し、電圧Ｖｏに対応する駆動周波数帯域Ｆｗ内の駆動周波数ｆｗ１を決定する。ステップＳ４において、処理部１６は、決定された駆動周波数ｆｗ１で駆動回路１２に各ＦＥＴのゲートに駆動信号を送る。駆動回路１２は、送られた駆動信号に従い、時間ｔ２から時間ｔ３の間に駆動周波数ｆｗ１で圧電ポンプ２１を駆動する。時間ｔ２－ｔ３間は、例えば、２.５ｓｅｃである。すなわち、非駆動周波数ｆｚ１で圧電ポンプ２１に電圧を印加する時間は、ポンプの駆動時間に比べて非常に小さい。そこで、再び、時間ｔ３から、ステップＳ１からステップＳ４を繰り返すことで、圧電ポンプ２１の温度上昇に対して駆動周波数ｆｗ１よりも低い駆動周波数ｆｗ２で圧電ポンプ２１を駆動することができる。図９に示すように、圧電ポンプ２１の温度が上昇すると、圧電ポンプ２１への印加電圧が増加するので、駆動周波数が低くなるように制御部１５が制御する。これ以後も、ステップＳ１～Ｓ４を繰り返す。なお、時間ｔ５以降は、圧電ポンプ２１の温度上昇が飽和しているので、圧電ポンプ２１を駆動する駆動周波数ｆｗ３が同じになっている。 In step S1, the drive circuit 12 applies a voltage to the piezoelectric pump 21 at the non-drive frequency fz1 in the non-drive frequency band Fz between the time t1 and the time t2 according to an instruction from the processing unit 16 of the control unit 15. . The period from time t1 to t2 is, for example, 30 msec. Between time t1 and t2, the piezoelectric pump 21 does not perform the pump operation because the voltage of the non-drive frequency fz1 is applied. However, current flows through the piezoelectric pump 21 and the voltage detection circuit 13. In step S2, the control unit 15 detects the voltage Vo divided by the voltage detection circuit 13. In this case, the voltage Vo is an applied voltage applied to the piezoelectric pump 21. In step S3, the processing unit 16 checks the detected voltage Vo against a table stored in the storage unit 17, and determines the driving frequency fw1 in the driving frequency band Fw corresponding to the voltage Vo. In step S4, the processing unit 16 sends a drive signal to the gate of each FET to the drive circuit 12 at the determined drive frequency fw1. The drive circuit 12 drives the piezoelectric pump 21 at the drive frequency fw1 between time t2 and time t3 according to the transmitted drive signal. The period between the time t2 and the time t3 is, for example, 2.5 seconds. That is, the time during which the voltage is applied to the piezoelectric pump 21 at the non-driving frequency fz1 is much smaller than the driving time of the pump. Therefore, by repeating steps S1 to S4 again from time t3, the piezoelectric pump 21 can be driven at a drive frequency fw2 lower than the drive frequency fw1 with respect to the temperature rise of the piezoelectric pump 21. As shown in FIG. 9, when the temperature of the piezoelectric pump 21 increases, the voltage applied to the piezoelectric pump 21 increases, so that the control unit 15 controls the driving frequency to decrease. Thereafter, steps S1 to S4 are repeated. Since the temperature rise of the piezoelectric pump 21 is saturated after time t5, the driving frequency fw3 for driving the piezoelectric pump 21 is the same.
　実施の形態１のポンプ装置１１による効果を図１７及び図１８を参照して説明する。図１７は、ポンプ装置を駆動する電池の寿命を示すグラフ図である。図１８は、ポンプ装置の電気効率を示すグラフ図である。図１７に示すように、温度に応じて駆動周波数の制御を実施した場合のグラフＧｋは、駆動周波数の制御を実施しなかったグラフＧｍよりも圧電ポンプ２１を駆動する駆動電池の寿命が延びている。駆動周波数の制御を実施しなかった場合、駆動時間が４５０時間を超えたあたりで電池電圧が３Ｖ以下に落ちている。これに対して、温度に対応して駆動周波数の制御を実施した場合、駆動時間が６００分を超えても電池電圧は３．２Ｖ以上有している。 The effect of the pump device 11 according to the first embodiment will be described with reference to FIGS. FIG. 17 is a graph showing the life of the battery that drives the pump device. FIG. 18 is a graph showing the electrical efficiency of the pump device. As shown in FIG. 17, the graph Gk in the case where the driving frequency is controlled according to the temperature has a longer life of the driving battery for driving the piezoelectric pump 21 than the graph Gm in which the driving frequency is not controlled. I have. When the control of the driving frequency was not performed, the battery voltage dropped to 3 V or less around the time when the driving time exceeded 450 hours. On the other hand, when the drive frequency is controlled in accordance with the temperature, the battery voltage has 3.2 V or more even when the drive time exceeds 600 minutes.
　また、図１８に示すように、温度に応じて駆動周波数の制御を実施した場合のグラフＧｎは、駆動周波数の制御を実施しなかったグラフＧｐよりも全ての温度範囲にわたって電気効率が向上している。特に、常温よりも低温領域及び高温領域において、電気効率が上昇している。このように、温度に応じて駆動周波数を変化させることで、圧電ポンプ２１の消費電力を低減することができる。 Further, as shown in FIG. 18, the graph Gn in the case where the driving frequency is controlled according to the temperature shows that the electric efficiency is improved over the entire temperature range as compared with the graph Gp in which the driving frequency is not controlled. I have. In particular, the electric efficiency increases in a lower temperature region and a higher temperature region than normal temperature. As described above, the power consumption of the piezoelectric pump 21 can be reduced by changing the driving frequency according to the temperature.
　以上のように、ポンプ装置１１は、圧電ポンプ２１と、圧電ポンプ２１に印加される印加電圧を検出する、電圧検出回路１３と制御部１５とで構成される電圧検出部と、圧電ポンプ２１を駆動可能な駆動周波数帯域Ｆｗの帯域外の第１の周波数である非駆動周波数ｆ１における入力電圧Ｖｃにより得られる圧電ポンプ２１の出力電圧Ｖｏを基に、圧電ポンプ２１を駆動する、駆動周波数帯域Ｆｗ内の第２の周波数である駆動周波数ｆｏを決定する制御部１５と、を備える。これだけの構成により、圧電ポンプ２１の温度変化に対応して変化する駆動周波数帯域Ｆｗの帯域外の第１の周波数における出力電圧Ｖｏを検出する。この測定された出力電圧Ｖｏを基に、圧電ポンプ２１を駆動する第２の周波数を決定するので、圧電ポンプ２１の温度変化に対応した適切な周波数で圧電ポンプ２１を駆動することができる。これにより、圧電ポンプ２１の電気効率を向上させることができる。また、第２の周波数は一定の周波数でよいので、周波数をスキャンして駆動周波数ｆｏを検出するよりも、駆動周波数ｆｏを高速に決定することができる。したがって、ポンプ駆動と停止動作を繰り返す搾乳機に用いられるポンプ装置に特に適している。 As described above, the pump device 11 includes the piezoelectric pump 21, a voltage detecting unit configured to detect the applied voltage applied to the piezoelectric pump 21, the voltage detecting circuit 13 and the control unit 15, and the piezoelectric pump 21. A driving frequency band Fw for driving the piezoelectric pump 21 based on the output voltage Vo of the piezoelectric pump 21 obtained by the input voltage Vc at the non-driving frequency f1 which is the first frequency outside the drivable driving frequency band Fw. And a control unit 15 that determines a drive frequency fo which is a second frequency among the above. With this configuration, the output voltage Vo at the first frequency outside the driving frequency band Fw that changes in response to the temperature change of the piezoelectric pump 21 is detected. Since the second frequency for driving the piezoelectric pump 21 is determined based on the measured output voltage Vo, the piezoelectric pump 21 can be driven at an appropriate frequency corresponding to the temperature change of the piezoelectric pump 21. Thereby, the electric efficiency of the piezoelectric pump 21 can be improved. Further, since the second frequency may be a constant frequency, the driving frequency fo can be determined faster than scanning the frequency to detect the driving frequency fo. Therefore, it is particularly suitable for a pump device used in a milking machine that repeats pump driving and stopping operations.
　なお、電圧検出回路１３は、インピーダンス素子で構成されていれば、抵抗に限られずインダクタを用いてもよい。図１９は、実施の形態１における駆動回路及び電圧検出回路の変形例を示す回路図である。電圧検出回路１３ａはインダクタＬ１を有する。インダクタＬ１の一端に電源回路１４からの入力電圧Ｖｃが印加される。インダクタＬ１の他端は、第１ＦＥＴ６１及び第３ＦＥＴ６３のそれぞれのドレインと接続される。このように、電圧検出回路１３ａは電圧検出回路１３の接続先をＧＮＤから電源回路１４に置き換えている。電圧検出回路１３ａは、電圧検出回路１３と同様に、インダクタＬ１と圧電ポンプ２１の分圧により駆動回路１２への入力電圧Ｖｏを得ることが可能である。駆動回路１２の他端はグランドに接続されているので、入力電圧Ｖｏが圧電ポンプ２１への印加電圧となる。 The voltage detection circuit 13 is not limited to a resistor and may be an inductor as long as the voltage detection circuit 13 is configured by an impedance element. FIG. 19 is a circuit diagram showing a modification of the drive circuit and the voltage detection circuit according to the first embodiment. The voltage detection circuit 13a has an inductor L1. The input voltage Vc from the power supply circuit 14 is applied to one end of the inductor L1. The other end of the inductor L1 is connected to respective drains of the first FET 61 and the third FET 63. As described above, the voltage detection circuit 13 a replaces the connection destination of the voltage detection circuit 13 from GND to the power supply circuit 14. Similarly to the voltage detection circuit 13, the voltage detection circuit 13a can obtain the input voltage Vo to the drive circuit 12 by dividing the voltage of the inductor L1 and the piezoelectric pump 21. Since the other end of the drive circuit 12 is connected to the ground, the input voltage Vo is the voltage applied to the piezoelectric pump 21.
　また、インピーダンス素子を駆動回路１２の電源側に接続する場合インピーダンス素子の分圧比が小さすぎる場合には出力電圧検出回路の入力範囲を超える場合があるので、その場合は分圧するなどすればよい。 In addition, when the impedance element is connected to the power supply side of the drive circuit 12, if the voltage division ratio of the impedance element is too small, the impedance may exceed the input range of the output voltage detection circuit. In such a case, the voltage may be divided.
（実施の形態２）
　次に、本発明の実施の形態２のポンプ装置について図２０、図２１を参照して説明する。図２０は、実施の形態２における流体の流れる方向を示す説明図である。図２１は、実施の形態２におけるポンプ装置の時間と圧力との関係を示すグラフ図である。 (Embodiment 2)
Next, a pump device according to a second embodiment of the present invention will be described with reference to FIGS. FIG. 20 is an explanatory diagram illustrating a flowing direction of a fluid according to the second embodiment. FIG. 21 is a graph showing a relationship between time and pressure of the pump device according to the second embodiment.
　実施の形態１のポンプ装置１１は、吸引器５１の吸引装置として用いられていた。これに対して、実施の形態２のポンプ装置１１は、加圧器５２の加圧装置として用いられる。したがって、図２０に示すように、空気などの流体は、圧電ポンプ２１から流体を溜めるカフ５３ａに向けて流れる。バルブ５５が閉状態のときに、圧電ポンプ２１からカフ５３ａに向けて流体が流れるので、カフ５３ａ内の圧力が徐々に上昇する。また、バルブ５５が開状態になると、カフ５３ａ内の流体が開放されてカフ５３ａ内の圧力が下がる。加圧器５２の具体例として、血圧計、マッサージャー、ｐＭＤＩ（pressurized Metered-Dose Inhaler）、ネブライザが挙げられる。 The pump device 11 according to the first embodiment has been used as a suction device for the suction device 51. On the other hand, the pump device 11 of the second embodiment is used as a pressurizing device of the pressurizer 52. Accordingly, as shown in FIG. 20, a fluid such as air flows from the piezoelectric pump 21 toward the cuff 53a for storing the fluid. When the valve 55 is in the closed state, the fluid flows from the piezoelectric pump 21 toward the cuff 53a, so that the pressure in the cuff 53a gradually increases. When the valve 55 is opened, the fluid in the cuff 53a is released, and the pressure in the cuff 53a decreases. Specific examples of the pressurizer 52 include a sphygmomanometer, a massager, a pMDI (pressurized @ Metered-Dose @ Inhaler), and a nebulizer.
　実施の形態２のポンプ装置１１は、実施の形態１のポンプ装置１１と同じ構成要素を備える。したがって、実施の形態２におけるポンプ装置１１は、以下に記載した事項以外の構成は、実施の形態１のポンプ装置１１と共通である。 The pump device 11 according to the second embodiment includes the same components as the pump device 11 according to the first embodiment. Therefore, the configuration of the pump device 11 according to the second embodiment other than the matters described below is common to the pump device 11 of the first embodiment.
　ポンプ装置１１を加圧装置として用いた場合であっても、温度変化に対応して駆動周波数を変化させることで、圧電ポンプ２１の出力を向上させることができる。図２１に示すように、温度変化に対応して駆動周波数を変化させない場合、圧電ポンプ２１の駆動時間が長くなると、自己発熱により圧電ポンプ２１の温度が上昇する。これにより、圧電ポンプ２１から排出する流体の圧力を上げることができなくなる。これに対して、温度変化に対応して駆動周波数を変化させる場合、圧電ポンプ２１の温度が上昇しても、圧電ポンプ２１から排出する流体の圧力を上げることができる。この結果、流体の等速加圧を実現することができる。 っ て も Even when the pump device 11 is used as a pressurizing device, the output of the piezoelectric pump 21 can be improved by changing the drive frequency in accordance with the temperature change. As shown in FIG. 21, when the driving frequency is not changed in accordance with the temperature change, if the driving time of the piezoelectric pump 21 becomes longer, the temperature of the piezoelectric pump 21 increases due to self-heating. As a result, the pressure of the fluid discharged from the piezoelectric pump 21 cannot be increased. On the other hand, when the drive frequency is changed according to the temperature change, the pressure of the fluid discharged from the piezoelectric pump 21 can be increased even when the temperature of the piezoelectric pump 21 increases. As a result, uniform pressurization of the fluid can be realized.
　以上のように、実施の形態２によれば、ポンプ装置１１を加圧装置として用いる場合でも、圧電ポンプの温度に応じて、駆動周波数を変化させることで、低温時の圧電ポンプ２１の起動時や、連続運転時にも加圧能力を維持することができる。 As described above, according to the second embodiment, even when the pump device 11 is used as a pressurizing device, the driving frequency is changed in accordance with the temperature of the piezoelectric pump, thereby making it possible to start the piezoelectric pump 21 at a low temperature. Also, the pressurizing capacity can be maintained during continuous operation.
（実施の形態３）
　次に、本発明の実施の形態３のポンプ装置について図２２を参照して説明する。図２２は、実施の形態３におけるポンプ装置のブロック図である。 (Embodiment 3)
Next, a pump device according to a third embodiment of the present invention will be described with reference to FIG. FIG. 22 is a block diagram of a pump device according to the third embodiment.
　実施の形態３のポンプ装置１１ａは、圧電ポンプ２１が自己発熱により損傷を受けるのを防止する機能を有する。実施の形態３における制御部１５ａの記憶部１７ａには、出力電圧Ｖｏと駆動周波数ｆｏとの関係に加えて出力電圧Ｖｏの上限値が記憶されている。この点において、実施の形態１におけるポンプ装置１１と実施の形態３のポンプ装置１１ａとが異なる。この点及び以下に記載した事項以外の構成は、実施の形態１のポンプ装置１１と実施の形態３のポンプ装置１１ａと共通である。 The pump device 11a according to the third embodiment has a function of preventing the piezoelectric pump 21 from being damaged by self-heating. In the storage unit 17a of the control unit 15a according to the third embodiment, an upper limit value of the output voltage Vo is stored in addition to the relationship between the output voltage Vo and the driving frequency fo. In this respect, the pump device 11 according to the first embodiment is different from the pump device 11a according to the third embodiment. The configuration other than this point and the matters described below is common to the pump device 11 of the first embodiment and the pump device 11a of the third embodiment.
　ポンプ装置１１ａの駆動制御について、図２３を参照して説明する。図２３はポンプ装置１１ａの駆動制御の流れを示すフローチャートである。実施の形態３におけるポンプ装置１１ａの駆動制御は、実施の形態１のポンプ装置１１の駆動制御の後に実施される。したがって、実施の形態１のステップＳ１～ステップＳ４の処理により、圧電ポンプ２１を駆動する駆動周波数ｆｏが決定されている。したがって、ステップＳ１１において、駆動回路１２は、処理部１６より送られた駆動信号に従い、決定された駆動周波数ｆｏで圧電ポンプ２１を駆動する。次に、ステップＳ１２において、駆動回路１２は、処理部１６からの指示にしたがって、非駆動周波数帯域Ｆｚ内の非駆動周波数ｆ１で圧電ポンプ２１に電圧を印加する。圧電ポンプ２１は、非駆動周波数ｆ１の電圧が印加されているので、ポンプ動作をしない。しかしながら、圧電ポンプ２１及び電圧検出回路１３に電流が流れる。制御部１５は、電圧検出回路１３に分圧された電圧Ｖｏを検出する。この場合、電圧Ｖｏは圧電ポンプ２１に印加される印加電圧である。ステップＳ１３において、処理部１６は、検出された電圧Ｖｏが記憶部１７に記憶されている上限値と比較する。ステップＳ１３のＹｅｓのように、電圧Ｖｏが上限値未満である場合、ステップＳ１１に戻る。ステップＳ１３のＮｏのように、電圧Ｖｏが上限値未満でない場合、ステップＳ１４において、制御部１５ａは、圧電ポンプ２１の駆動を低下させる。これにより、圧電ポンプ２１の温度が低下するので、駆動回路１２の出力電圧Ｖｏを低下させることができる。この後、再びステップＳ１１からの処理を繰り返すことで、駆動回路１２の出力電圧Ｖｏが上限値未満になるまで圧電ポンプ２１の駆動を低下させることができる。 駆 動 Drive control of the pump device 11a will be described with reference to FIG. FIG. 23 is a flowchart showing the flow of drive control of the pump device 11a. The drive control of the pump device 11a according to the third embodiment is performed after the drive control of the pump device 11 according to the first embodiment. Therefore, the drive frequency fo for driving the piezoelectric pump 21 is determined by the processing of steps S1 to S4 of the first embodiment. Therefore, in step S11, the drive circuit 12 drives the piezoelectric pump 21 at the determined drive frequency fo according to the drive signal sent from the processing unit 16. Next, in step S12, the drive circuit 12 applies a voltage to the piezoelectric pump 21 at the non-drive frequency f1 in the non-drive frequency band Fz according to the instruction from the processing unit 16. The piezoelectric pump 21 does not perform the pump operation because the voltage of the non-drive frequency f1 is applied. However, current flows through the piezoelectric pump 21 and the voltage detection circuit 13. The control unit 15 detects the voltage Vo divided by the voltage detection circuit 13. In this case, the voltage Vo is an applied voltage applied to the piezoelectric pump 21. In step S13, the processing unit 16 compares the detected voltage Vo with the upper limit value stored in the storage unit 17. If the voltage Vo is lower than the upper limit value, as in Yes in step S13, the process returns to step S11. When the voltage Vo is not less than the upper limit value like No in Step S13, the control unit 15a lowers the driving of the piezoelectric pump 21 in Step S14. Thereby, the temperature of the piezoelectric pump 21 decreases, so that the output voltage Vo of the drive circuit 12 can be reduced. Thereafter, by repeating the processing from step S11 again, the drive of the piezoelectric pump 21 can be reduced until the output voltage Vo of the drive circuit 12 becomes lower than the upper limit value.
　圧電ポンプ２１の駆動を低下させる方法は、例えば、制御部１５ａからの指示により電源回路１４から駆動回路１２への入力電圧Ｖｃを低下させる。また、処理部１６から各ＦＥＴへの駆動信号の駆動デューティ比を変化させてもよい。また、駆動回路１２の駆動周波数を変化させてもよい。 The method of reducing the driving of the piezoelectric pump 21 is, for example, to reduce the input voltage Vc from the power supply circuit 14 to the drive circuit 12 according to an instruction from the control unit 15a. Further, the drive duty ratio of the drive signal from the processing unit 16 to each FET may be changed. Further, the drive frequency of the drive circuit 12 may be changed.
　このように、実施の形態３における圧電ポンプ２１の駆動制御によれば、温度上限に対応する出力電圧の上限値未満で圧電ポンプ２１を駆動することができるので、最大電力で圧電ポンプ２１を使用しても圧電ポンプ２１が破壊されるのを防止することができる。 As described above, according to the drive control of the piezoelectric pump 21 in the third embodiment, the piezoelectric pump 21 can be driven with an output voltage lower than the upper limit value corresponding to the temperature upper limit. Even in this case, the piezoelectric pump 21 can be prevented from being broken.
　また、実施の形態３において、電圧検出回路１３を図２４に示す電圧検出回路１３ｂに替えてもよい。電圧検出回路１３ｂは、抵抗器Ｒｓに加えて、一端が第２ＦＥＴ６２及び第４ＦＥＴ６４のそれぞれのソースと接続され、他端がグランドに接続されるコンデンサＣｓを備える。コンデンサＣｓは平滑コンデンサとして機能する。電圧検出回路１３の場合、抵抗器Ｒｓの両端に制御部１５からの出力信号の周波数成分がノイズとして検出される場合がある。電圧検出回路１３ｂであれば、コンデンサＣｓにより整流されるので、出力電圧Ｖｏの検出精度を向上することができる。 In the third embodiment, the voltage detection circuit 13 may be replaced with a voltage detection circuit 13b shown in FIG. The voltage detection circuit 13b includes, in addition to the resistor Rs, a capacitor Cs having one end connected to each source of the second FET 62 and the fourth FET 64 and the other end connected to ground. The capacitor Cs functions as a smoothing capacitor. In the case of the voltage detection circuit 13, the frequency component of the output signal from the control unit 15 may be detected as noise at both ends of the resistor Rs. In the case of the voltage detection circuit 13b, since the voltage is rectified by the capacitor Cs, the detection accuracy of the output voltage Vo can be improved.
　また、図２５に示すような増幅回路６７を制御部１５のＩ／Ｏポート６６と、抵抗器Ｒｓの一端側（グランド側の反対側）との間に接続してもよい。増幅回路６７は、増幅器Ｑと、抵抗器Ｒ１と、抵抗器Ｒ２と、コンデンサＣｓａとを備える。増幅器Ｑの非反転入力端子（＋）に出力電圧Ｖｏが入力され、反転入力端子（－）に抵抗器Ｒ１、Ｒ２のそれぞれの一端が接続される。抵抗器Ｒ１の他端は、グランドと接続される。抵抗器Ｒ２の他端は、増幅器Ｑの出力端子に接続される。増幅器Ｑの出力端子は、制御部１５のＩ／Ｏポート６６と接続される。また、増幅器Ｑの反転入力端子（－）と出力端子との間にコンデンサＣｓａが接続される。コンデンサＣｓａを有する増幅回路６７を挿入する場合は、電圧検出回路１３ｂのコンデンサＣｓを省略してもよい。 Also, an amplifier circuit 67 as shown in FIG. 25 may be connected between the I / O port 66 of the control unit 15 and one end of the resistor Rs (opposite the ground side). The amplifier circuit 67 includes an amplifier Q, a resistor R1, a resistor R2, and a capacitor Csa. The output voltage Vo is input to the non-inverting input terminal (+) of the amplifier Q, and one end of each of the resistors R1 and R2 is connected to the inverting input terminal (-). The other end of the resistor R1 is connected to the ground. The other end of the resistor R2 is connected to the output terminal of the amplifier Q. The output terminal of the amplifier Q is connected to the I / O port 66 of the control unit 15. Further, a capacitor Csa is connected between the inverting input terminal (−) of the amplifier Q and the output terminal. When the amplifier circuit 67 having the capacitor Csa is inserted, the capacitor Cs of the voltage detection circuit 13b may be omitted.
　増幅回路６７により、抵抗器Ｒｓ間の電圧を増幅し、かつ、整流することができる。これにより、出力電圧のＳ／Ｎ比を向上させ、検出精度を向上することができる。なお、制御部１５がＡ／Ｄポートを有する場合、Ｉ／Ｏポート６６の代わりにＡ／Ｄポートに接続してもよい。 (4) The voltage between the resistors Rs can be amplified and rectified by the amplifier circuit 67. Thereby, the S / N ratio of the output voltage can be improved, and the detection accuracy can be improved. When the control unit 15 has an A / D port, it may be connected to the A / D port instead of the I / O port 66.
（実施の形態４）
　次に、本発明の実施の形態４のポンプ装置について図２６及び図２７を参照して説明する。図２６は、実施の形態４におけるポンプ装置を用いた加圧器の流体の流れを示す説明図である。図２７は、実施の形態４における駆動回路及び電圧検出回路の回路図である。 (Embodiment 4)
Next, a pump device according to a fourth embodiment of the present invention will be described with reference to FIGS. FIG. 26 is an explanatory diagram illustrating a flow of a fluid in a pressurizer using the pump device according to the fourth embodiment. FIG. 27 is a circuit diagram of a drive circuit and a voltage detection circuit according to the fourth embodiment.
　実施の形態４では、実施の形態２の加圧器５２において、圧電ポンプ２１を並列に２個配置している。また、容器５３の替わりにノズル７１と圧電ポンプ２１とが接続されている。また、実施の形態４の吐出器５２ａは、ノズル７１が大気開放されているので、実施の形態２のようにバルブ５５を備えていない。この点及び以下に記載した事項以外の構成は、実施の形態４のポンプ装置１１は、実施の形態２のポンプ装置１１と共通である。なお、実施の形態４のポンプ装置１１の駆動制御は実施の形態３と同様である。実施の形態４におけるポンプ装置を用いた吐出器５２ａは、例えば、ネブライザに採用される。 In the fourth embodiment, two piezoelectric pumps 21 are arranged in parallel in the pressurizer 52 of the second embodiment. The nozzle 71 and the piezoelectric pump 21 are connected instead of the container 53. Further, the discharge device 52a of the fourth embodiment does not include the valve 55 unlike the second embodiment because the nozzle 71 is open to the atmosphere. Except for this point and the configuration described below, the pump device 11 of the fourth embodiment is common to the pump device 11 of the second embodiment. The drive control of the pump device 11 of the fourth embodiment is the same as that of the third embodiment. Discharger 52a using the pump device according to the fourth embodiment is used for, for example, a nebulizer.
　圧電ポンプ２１を並列にノズル７１に対して並列に接続することで、ノズル７１から排出する流量を増やすことができる。さらには、圧電ポンプ２１が電気的に並列に接続されるので、電圧検出回路との分圧比により出力電圧Ｖｏが相対的に大きくなる。これにより、測定レンジが拡がるので、出力電圧Ｖｏの検出精度を向上させることができる。なお、圧電ポンプ２１は３つ以上並列に接続してもよい。 流量 By connecting the piezoelectric pump 21 in parallel with the nozzle 71, the flow rate discharged from the nozzle 71 can be increased. Furthermore, since the piezoelectric pumps 21 are electrically connected in parallel, the output voltage Vo becomes relatively large due to the voltage division ratio with the voltage detection circuit. As a result, the measurement range is expanded, so that the detection accuracy of the output voltage Vo can be improved. Note that three or more piezoelectric pumps 21 may be connected in parallel.
　また、実施の形態３と同様に、上限値未満で駆動するので、フルパワーで駆動しても圧電ポンプ２１が壊れるのを防止することができる。特に、高地のような気圧の低い場所での使用に適している。高地の場合、エンジンの過剰振幅による故障が生じやすいが、これを防止することができる。 Also, as in the third embodiment, the piezoelectric pump 21 is driven at less than the upper limit, so that the piezoelectric pump 21 can be prevented from being broken even when driven at full power. In particular, it is suitable for use in places with low atmospheric pressure, such as high altitudes. In the case of high altitude, a failure due to excessive amplitude of the engine is likely to occur, but this can be prevented.
　また、さらに、図２７の駆動回路１２は、ポンプ動作時には電圧検出回路に電圧が印加しないようにする第５ＦＥＴ６５を備える。第５ＦＥＴ６５のゲートは制御部１５に接続され、ドレインは抵抗器Ｒｓの一端と接続され、ソースはグランドに接続されている。制御部１５からの駆動信号により、第５ＦＥＴ６５はスイッチング素子として機能する。ポンプ動作時に、第５ＦＥＴ６５が導通状態になることで、電圧検出回路が短絡する。これにより、出力電圧Ｖｏ＝０[Ｖ]となるので、電気効率をさらに向上することができる。 Further, the drive circuit 12 in FIG. 27 further includes a fifth FET 65 for preventing a voltage from being applied to the voltage detection circuit during the pump operation. The gate of the fifth FET 65 is connected to the control unit 15, the drain is connected to one end of the resistor Rs, and the source is connected to ground. The fifth FET 65 functions as a switching element according to the drive signal from the control unit 15. During the pump operation, the voltage detection circuit is short-circuited because the fifth FET 65 is turned on. As a result, the output voltage Vo becomes 0 [V], so that the electric efficiency can be further improved.
　本発明は、上記実施の形態のものに限らず、次のように変形実施することができる。 The present invention is not limited to the above-described embodiment, but can be modified as follows.
　（１）上記各実施の形態において、非駆動周波数帯域Ｆｚは、共振周波数ｆｒ未満及び***振周波数ｆａ以上の帯域であったが、これに限られない。非駆動周波数帯域Ｆｚは、共振周波数ｆｒから予め定められた範囲以下の帯域及び***振周波数ｆａから予め定められた範囲以上の帯域であってもよい。例えば、非駆動周波数帯域Ｆｚは共振周波数ｆｒから共振周波数ｆｒの２０％低い値以下の帯域及び***振周波数ｆａから***振周波数ｆａの２０％高い値以上の帯域であってもよい。この構成であれば、駆動周波数帯域Ｆｗが通常の使用状態の温度によってシフトしても、シフト後の非駆動周波数帯域Ｆｚはシフト前の非駆動周波数帯域Ｆｚに含まれるので、圧電ポンプ２１の温度特性を精度よく監視することができる。通常の使用状態の温度として、例えば、－１０℃～＋７０℃の範囲である。 (1) In each of the above embodiments, the non-drive frequency band Fz is a band lower than the resonance frequency fr and higher than or equal to the anti-resonance frequency fa, but is not limited thereto. The non-drive frequency band Fz may be a band below a predetermined range from the resonance frequency fr and a band above a predetermined range from the anti-resonance frequency fa. For example, the non-drive frequency band Fz may be a band having a value lower than the resonance frequency fr by 20% or less than the resonance frequency fr and a band having a value higher than the anti-resonance frequency fa by 20% or higher than the anti-resonance frequency fa. With this configuration, even if the driving frequency band Fw shifts due to the temperature in a normal use state, the shifted non-driving frequency band Fz is included in the non-driving frequency band Fz before the shift. Characteristics can be monitored accurately. The temperature in a normal use state is, for example, in a range of −10 ° C. to + 70 ° C.
　（２）上記各実施の形態において、分圧された出力電圧Ｖｏを検出するときの電源回路１４から入力される入力電圧は、圧電ポンプ２１を駆動周波数帯域Ｆｗで駆動するときよりも低い電圧であってもよい。この構成により、圧電ポンプ２１の出力電圧Ｖｏの検出時の消費電力を低減することができる。 (2) In each of the above embodiments, the input voltage input from the power supply circuit 14 when detecting the divided output voltage Vo is a lower voltage than when the piezoelectric pump 21 is driven in the drive frequency band Fw. There may be. With this configuration, power consumption when detecting the output voltage Vo of the piezoelectric pump 21 can be reduced.
　なお、本発明は、「圧電ポンプと、前記圧電ポンプに印加される印加電圧を検出する電圧検出部と、前記圧電ポンプを駆動可能な駆動周波数帯域の帯域外の第１の周波数における前記印加電圧を基に、前記圧電ポンプを駆動する、前記駆動周波数帯域内の第２の周波数を決定する制御部と、を備える、ポンプ装置」としている。ところで、圧電ポンプの温度を検出するには圧電ポンプ周辺にサーミスタ、熱電対などの感温素子を配置するか、もしくはポンプ内部の温度を測定するかしか選択肢がない。つまり、感温素子が配置されてなければ、ポンプ内部の温度を測定するしか方法がない。したがって、サーミスタ等の感温素子を用いることなく圧電ポンプの温度特性を補正していれば、本発明を利用している蓋然性が高いと考える。 In addition, the present invention provides a piezoelectric pump, a voltage detection unit that detects an applied voltage applied to the piezoelectric pump, and the applied voltage at a first frequency outside a driving frequency band capable of driving the piezoelectric pump. And a control unit that drives the piezoelectric pump based on the control frequency and determines a second frequency in the drive frequency band. By the way, in order to detect the temperature of the piezoelectric pump, there is no choice but to arrange a temperature-sensitive element such as a thermistor or a thermocouple around the piezoelectric pump, or to measure the temperature inside the pump. That is, if no temperature sensing element is provided, there is no other way but to measure the temperature inside the pump. Therefore, if the temperature characteristics of the piezoelectric pump are corrected without using a temperature-sensitive element such as a thermistor, it is considered that the possibility of using the present invention is high.
　本発明は、圧電ポンプを備えるポンプ装置に適用可能である。 The present invention is applicable to a pump device including a piezoelectric pump.
　　１１　　　ポンプ装置
　　１２、１２ａ　駆動回路
　　１３、１３ａ、１３ｂ　電圧検出回路
　　１４　　　電源回路
　　１５　　　制御部
　　１６　　　処理部
　　１７　　　記憶部
　　２１　　　圧電ポンプ
　　２２　　　カバー板
　　２３　　　流路板
　　２４　　　対向板
　　２５　　　接着層
　　２６　　　振動板
　　２７　　　圧電素子
　　２８　　　絶縁板
　　２９　　　給電板
　　３０　　　スペーサ板
　　３１　　　蓋板
　　３３　　　吸引口
　　３４　　　吐出口
　　３５　　　外部接続端子
　　３６　　　外部接続端子
　　３８　　　開口部
　　３９　　　可動部
　　４０　　　ポンプ室
　　４１　　　中央部
　　４２　　　打撃部
　　４３　　　連結部
　　４４　　　枠部
　　４５　　　内部接続端子
　　４６　　　ポンプ室
　　５１　　　吸引器
　　５２　　　加圧器
　　５３　　　容器
　　５３ａ　　カフ
　　５５　　　バルブ
　　６１　　　第１ＦＥＴ
　　６２　　　第２ＦＥＴ
　　６３　　　第３ＦＥＴ
　　６４　　　第４ＦＥＴ
　　６５　　　第５ＦＥＴ
　　６６　　　Ｉ／Ｏポート
　　６７　　　増幅回路
　　７１　　　ノズル
　　Ｃｓ、Ｃｓａ　コンデンサ
　　Ｆｚ　　　非駆動周波数帯域
　　Ｆｗ　　　駆動周波数帯域
　　Ｒｓ　　　抵抗器 Reference Signs List 11 pump device 12, 12a drive circuit 13, 13a, 13b voltage detection circuit 14 power supply circuit 15 control unit 16 processing unit 17 storage unit 21 piezoelectric pump 22 cover plate 23 flow path plate 24 facing plate 25 adhesive layer 26 vibration plate 27 piezoelectric element Reference Signs List 28 Insulation plate 29 Power supply plate 30 Spacer plate 31 Cover plate 33 Suction port 34 Discharge port 35 External connection terminal 36 External connection terminal 38 Opening 39 Movable part 40 Pump chamber 41 Central part 42 Hitting part 43 Connecting part 44 Frame part 45 Internal connection Terminal 46 Pump chamber 51 Suction unit 52 Pressurizer 53 Container 53a Cuff 55 Valve 61 First FET
62 2nd FET
63 3rd FET
64 4th FET
65 Fifth FET
66 I / O port 67 Amplifying circuit 71 Nozzle Cs, Csa Capacitor Fz Non-drive frequency band Fw Drive frequency band Rs Resistor

Claims (7)

  1. 　圧電ポンプと、
    　前記圧電ポンプに印加される印加電圧を検出する電圧検出部と、
    　前記圧電ポンプを駆動可能な駆動周波数帯域の帯域外の第１の周波数における前記印加電圧を基に、前記圧電ポンプを駆動する、前記駆動周波数帯域内の第２の周波数を決定する制御部と、
    　を備える、ポンプ装置。     A piezoelectric pump,
    A voltage detection unit that detects an applied voltage applied to the piezoelectric pump,
    A control unit that drives the piezoelectric pump based on the applied voltage at a first frequency outside a driving frequency band capable of driving the piezoelectric pump, and determines a second frequency within the driving frequency band,
    A pump device comprising:
  2. 　前記圧電ポンプと電気的に接続されるインピーダンス素子を備え、
    　前記電圧検出部は、前記圧電ポンプと前記インピーダンス素子とにより分圧された電圧から前記印加電圧を検出する、
    　請求項１に記載のポンプ装置。     Comprising an impedance element electrically connected to the piezoelectric pump,
    The voltage detector detects the applied voltage from a voltage divided by the piezoelectric pump and the impedance element,
    The pump device according to claim 1.
  3. 　前記圧電ポンプに電力を供給する電力供給部を備え、
    　前記制御部は前記電力供給部と接続され、前記圧電ポンプの出力電圧に応じて前記圧電ポンプに供給する前記電力を調整する、
    　請求項１または２に記載のポンプ装置。     A power supply unit that supplies power to the piezoelectric pump,
    The control unit is connected to the power supply unit, and adjusts the power supplied to the piezoelectric pump according to an output voltage of the piezoelectric pump,
    The pump device according to claim 1.
  4. 　前記制御部は、モデル化された前記圧電ポンプの容量と前記圧電ポンプの温度との関係、または、前記圧電ポンプの出力電圧と前記圧電ポンプの温度との関係を基に、前記第２の周波数を決定する、
    　請求項１から３のいずれか１つに記載のポンプ装置。     The controller controls the second frequency based on a relationship between a modeled capacity of the piezoelectric pump and a temperature of the piezoelectric pump, or a relationship between an output voltage of the piezoelectric pump and a temperature of the piezoelectric pump. Determine the
    The pump device according to claim 1.
  5. 　前記インピーダンス素子は抵抗である、
    　請求項２に記載のポンプ装置。     The impedance element is a resistor;
    The pump device according to claim 2.
  6. 　前記インピーダンス素子はインダクタである、
    　請求項２に記載のポンプ装置。     The impedance element is an inductor;
    The pump device according to claim 2.
  7. 　分圧された出力電圧を検出するときの入力電圧は、前記圧電ポンプを駆動周波数帯域で駆動するときよりも低い電圧である、
    　請求項２から４のいずれか１つに記載のポンプ装置。     The input voltage when detecting the divided output voltage is a lower voltage than when the piezoelectric pump is driven in a drive frequency band.
    The pump device according to any one of claims 2 to 4.
PCT/JP2019/032422 2018-08-23 2019-08-20 Pump device WO2020040131A1 (en)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009158757A (en) * 2007-12-27 2009-07-16 Sony Corp Transformer, cooling device, and electronic appliance
JP2009233515A (en) * 2008-03-26 2009-10-15 Sony Corp Driving gear of piezoelectric element and electrical equipment as well as method of controlling piezoelectric element driving frequency
WO2013084709A1 (en) * 2011-12-09 2013-06-13 株式会社村田製作所 Drive circuit for piezoelectric element
WO2017037117A1 (en) * 2015-08-31 2017-03-09 Koninklijke Philips N.V. Electroactive polymer sensors and sensing methods

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009158757A (en) * 2007-12-27 2009-07-16 Sony Corp Transformer, cooling device, and electronic appliance
JP2009233515A (en) * 2008-03-26 2009-10-15 Sony Corp Driving gear of piezoelectric element and electrical equipment as well as method of controlling piezoelectric element driving frequency
WO2013084709A1 (en) * 2011-12-09 2013-06-13 株式会社村田製作所 Drive circuit for piezoelectric element
WO2017037117A1 (en) * 2015-08-31 2017-03-09 Koninklijke Philips N.V. Electroactive polymer sensors and sensing methods

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