Pump control device and pump control system

Abstract

A pump control device for controlling a pump (1) having a vibration actuator (10) which vibrates a vibrating body (30) via electromagnetic driving by supply of current to coils (50a, 50b), a sealed chamber (82) which has a movable wall (822) that is displaced by vibration of the vibrating body (30), and the inside volume of which is changed by displacement of the movable wall (822) such that fluid is drawn into or discharged from the inside thereof, and a discharge section (86) which is for fluid communication between the sealed chamber (82) and a tank (120) that stores the fluid discharged from the sealed chamber (82) and that increases the pressure of the fluid, said pump control device having: an acquisition section (146) which acquires pressure value information that indicates a the pressure of the fluid in the tank (120) or a value corresponding to the pressure; and a control section (140) which, on the basis of the acquired pressure value information, controls the driving frequency of the current supplied to the coils (50a, 50b).

Description

Cross - reference to related applications

[0001] This application claims priority based on Japanese Patent Application No. 2020 - 064576 filed on March 31, 2020 (the title of the invention is "Pump control device and pump control system"), and further, the content of this Japanese patent application is incorporated herein by reference in its entirety.

Technical Field

[0002] The present invention relates to a control device, and particularly to a control device for a pump using a vibration actuator driven in resonance.

Background Art

[0003] Conventionally, as pumps using an actuator driven at a resonance frequency, for example, pumps such as those disclosed in Patent Documents 1 and 2 are known.

[0004] In the pump of Patent Document 1, an actuator displaces a movable wall such as a piston or a diaphragm, and the displacement of this movable wall changes the volume of the pump chamber, thereby causing the inflow of the working fluid into the pump chamber and the outflow of the working fluid from the pump chamber. In this pump, the movement period of the movable wall itself is changed according to the displacement time, displacement amount, or displacement speed of the movable wall during the pump chamber volume compression stroke.

[0005] In addition, in the pump device of Patent Document 2, there are provided a variation imparting means for imparting a predetermined variation to one or more parameters among the frequency, amplitude, and phase of the alternating voltage applied to the vibrating body, and a frequency response characteristic measuring means for obtaining the frequency response characteristics at one or more predetermined frequencies, which takes the variation output from the variation imparting means as an input and outputs a physical quantity that changes according to the vibration of the vibrating body. In this pump device, control is performed so as to determine the frequency range of the alternating voltage output by the alternating voltage generating means according to the estimated value of the resonance frequency output from the resonance frequency estimating means.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] By the way, in pump devices, in recent years, miniaturization has been pursued, and those with high pump pressure and large flow rate are desired. However, in the pump of Cited Document 1, it is necessary to measure the displacement amount or displacement speed of the movable wall, etc. To achieve this, it is necessary to provide a measurement unit for measuring the displacement amount or displacement speed of the movable wall inside the pump. When providing the measurement unit inside the pump, there is a problem that miniaturization is difficult in order to secure the arrangement space. Further, in the configuration of Patent Document 2, since it involves processing for obtaining frequency response characteristics at one or more predetermined frequencies with respect to physical quantities that change according to the vibration of the vibrating body, and processing for estimating the resonance frequency of the vibrating body that changes according to parameter changes of the drive voltage, etc., there is a problem that control takes time.

[0008] The present invention has been made in view of such points, and an object thereof is to provide a pump control device and a pump control system that can be miniaturized, can secure more suitable pump pressure and flow rate, and can be stably driven.

Means for Solving the Problems

[0009] Such an object is achieved by the following (1) to ( 6 ) of the present invention. (1) A vibration actuator that vibrates a vibrating body by electromagnetic drive by supplying current to a coil, a sealed chamber having a movable wall that is displaced by the vibration of the vibrating body, and the internal volume is changed by the displacement of the movable wall, and fluid is sucked into or discharged from the inside, A discharge section that fluidly connects a tank that stores the fluid discharged from the sealed chamber and increases the pressure of the fluid and the sealed chamber, A pump control device for controlling a pump having An acquisition unit that acquires pressure value information indicating a value of the pressure of the fluid in the tank or a value corresponding to the pressure, Based on the acquired the above-mentioned pressure value information, a control unit that controls the drive frequency of the current supplied to the coil, and has and when the value of the pressure of the fluid in the tank reaches the switching pressure value, the control unit switches the driving frequency from a first driving frequency that maximizes the flow rate of the fluid from the pump to the tank to a second driving frequency that maximizes the pressure of the fluid in the tank. Pump control device.

[0010] (2) The control unit controls the drive frequency so that the current is supplied to the coil at the resonance frequency of the vibrating body that varies according to the pressure of the fluid in the tank. The pump control device according to (1) above.

[0011] (3) The pump control device according to (1) above, wherein the second driving frequency is higher than the first driving frequency.

[0013] ( 4 ) The pump control device according to (1) above, The pump, A pressure detection unit that measures the pressure of the fluid in the tank and obtains the pressure value information indicating the value of the pressure, the above-mentioned and has The acquisition unit acquires the pressure value information from the pressure detection unit. A pump control system.

[0014] 5 ( ) The pump control device according to (1) above, The pump, When increasing the pressure of the fluid in the tank, a timer that measures the drive time of the vibrating body and obtains the pressure value information indicating the drive time, and has The acquisition unit acquires the pressure value information from the timer. A pump control system.

[0015] 6 ( 6) The pump control device has a storage unit that stores a table showing the relationship between the preset driving time of the vibrating body and the pressure of the fluid in the tank that increases during driving. between The control unit controls the driving frequency using the table, as described in the above ([ ) of the pump control system. 5 ) [Advantages of the Invention]

[0016] According to the present invention, miniaturization is possible, and more suitable pump pressure and flow rate can be ensured, and stable driving can be achieved. [Brief Description of the Drawings]

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Figure 19

Figure 20

Figure 21

Figure 22

Figure 23

Figure 24

Figure 25

Mode for Carrying Out the Invention

[0018] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0019] (First Embodiment) <Overall Configuration of Pump Control System 100> FIG. 1 is a block diagram showing a schematic configuration of a pump control system 100 according to an embodiment of the present invention. As shown in FIG. 1, the pump control system 100 according to the present embodiment includes a pump 1, a tank unit 120, a pressure measurement unit (pressure detection unit) 130, and a microcomputer unit (control unit) 140.

[0020] The pump control system 100 can adjust the pressure of the fluid discharged from the pump 1, which is air (gas) in this embodiment, in the tank unit 120 and output it.

[0021] The pump 1 is frequency-controlled by a drive signal (current supply) output from the microcomputer unit 140. Specifically, a drive signal having a resonance frequency is input to the vibration actuator constituting the pump 1 to perform electromagnetic drive, and air as the fluid is supplied to the tank unit 120. First, an example of the pump 1 will be described with reference to FIGS. 2 to 11.

[0022] <Overall Configuration of Pump 1> FIG. 2 is an external perspective view of the pump unit of the pump in the pump control system according to the first embodiment of the present invention. FIG. 3 is a plan view showing the main configuration of the pump in the pump control system according to the first embodiment of the present invention. FIG. 4 is an exploded perspective view of the pump in the pump control system according to the first embodiment of the present invention. FIG. 5 is a perspective view of the coil core portion in the pump of the pump control system according to the first embodiment of the present invention. FIG. 6 is a perspective view of the vibrating body in the pump of the pump control system according to the first embodiment of the present invention. FIG. 7 is a cross-sectional plan view showing the internal configuration of the pump in the pump control system according to the first embodiment of the present invention. FIG. 8 is an exploded perspective view of the pump unit in the pump of the pump control system according to the first embodiment of the present invention.

[0023] In addition to FIGS. 2 to 8, in FIGS. 9 to 12, when explaining the pump, the vibration direction of the vibrating body that reciprocates and rotates in the vibration actuator of the pump in the pump control system is set to the direction shown in FIG. 3. Two directions orthogonal to this direction are respectively described as the lateral direction (left-right direction) and the height direction (up-down direction, also referred to as the thickness direction). Further, in the present embodiment, the expressions indicating directions such as left-right (lateral) and height (up-down) used to explain the configuration and operation of each part of the pump 1 are not absolute but relative. They are appropriate when each part of the pump is in the posture shown in the figure, but should be interpreted as being changed according to the change in the posture when the posture changes.

[0024] The pump 1 shown in FIGS. 2 and 3 discharges air by the action of the vibration actuator 10 driven electromagnetically. In the present embodiment, the pump has been described as discharging and inhaling air, but what is discharged and inhaled by the pump is not limited to air and may be any fluid, and is preferably a gas in particular.

[0025] As shown in Fig. 2, the pump 1 has a flat plate shape with a height (which is the length in the vertical direction on the drawing and corresponds to the thickness) shorter than both the width (the length in the left - right direction on the drawing) and the depth (the length in the depth direction on the drawing, which can also be said to be the vibration direction). Also, the depth is shorter than the width. Note that Fig. 2 is a perspective view of the pump 1 seen from the back side.

[0026] The pump 1 includes a vibration actuator 10 in which a vibrating body (movable body) 30 is provided so as to be reciprocally rotatable with respect to a fixed body 20 via a shaft portion 40, and a pump portion 80 (80a, 80b) that discharges and inhales air by driving the vibration actuator 10.

[0027] In this embodiment, the vibrating body 30 is provided in the case 21 of the fixed body 20 so as to be reciprocally rotatable via the shaft portion 40.

[0028] By the cooperation of a core portion 60 (60a, 60b) around which coils 50a, 50b are wound and magnets 70 (70a, 70b), the vibrating body 30 reciprocally moves, that is, vibrates, along the axial direction of the shaft portion 40 with respect to the fixed body 20. The pump 1 can discharge and inhale air from the discharge portion 86 by utilizing the vibration of the vibrating body 30.

[0029] In the pump 1, the vibrating body 30 is provided in the rectangular - shaped case 21 in a plan view so as to be reciprocally rotatable around a shaft portion 40 disposed at its center. The magnets 70a, 70b are provided on the inner surfaces of both end wall portions spaced apart in the longitudinal direction of the vibrating body 30. The coil - core portion 62a including the coil 50a and the core portion 60a is provided on the inner surface of the end wall portion of the case 21 on the side facing the magnet 70a, and the coil - core portion 62b including the coil 50b and the core portion 60b is provided on the inner surface of the end wall portion of the case 21 on the side facing the magnet 70b. The magnets 70a, 70b are preferably permanent magnets, for example.

[0030] <Vibration actuator 10> The vibration actuator 10 has a fixed body 20, a shaft portion 40, and a vibrating body 30 that is reciprocally rotatably supported with respect to the fixed body 20 via the shaft portion 40. A magnet 70 (70a, 70b) is provided on one of the fixed body 20 and the vibrating body 30, and a coil core portion 62 (62a, 62b) is provided on the other of the fixed body 20 and the vibrating body 30 such that the magnetization surface of the core faces the magnet 70. In the present embodiment, the magnet 70 (70a, 70b) is provided on the vibrating body 30, and the coil core portion 62 (62a, 62b) is provided on the fixed body 20 side. In other words, in the present embodiment, the vibrating body 30 includes the magnet 70 (70a, 70b), and the fixed body 20 includes the coil core portion 62 (62a, 62b). The vibration actuator 10 electromagnetically drives the vibrating body 30 by supplying current to the coils 50a and 50b, thereby vibrating the vibrating body 30 which is the vibrating body.

[0031] <fixed body 20> The fixed body 20 has a case 21, a cover 22, and coil core portions 62a and 62b. Further, a pump portion 80 (80a, 80b) is provided on the fixed body 20.

[0032] The case 21 functions as the housing of the pump 1 and has a rectangular box shape that is open on one side. A shaft portion 40 is erected in the case 21 and rotatably supports the vibrating body 30 disposed in the case 21.

[0033] Further, the coil core portions 62a and 62b are disposed on the inner surfaces of both end wall portions that are spaced apart in the longitudinal direction of the case 21 so as to face the magnets 70a and 70b of the vibrating body 30, respectively.

[0034] The opening portion of the case 21, in the present embodiment, the opening portion that is open upward is covered with the cover 22. Thereby, the case 21 and the cover 22 function as a hollow electromagnetic shield, and the pump 1 has a flat plate shape.

[0035] The shaft portion 40 is provided on the bottom surface of the case 21, at the center in the lateral and depth directions of the case 21, and extends in the height direction of the case 21. The shaft portion 40 is press-fitted into the shaft hole 23 of the cover 22, or fixed by adhesion or the like after insertion, in a state of being inserted into the bearing portion 34 of the vibrating body 30. Thereby, the shaft portion 40 is supported in a state of being spanned between the bottom surface of the case 21 and the cover 22 while being inserted into the bearing portion 34 of the vibrating body 30.

[0036] The coil core portions 62a and 62b are disposed opposite to each other on the inner surfaces of both end wall portions spaced apart in the longitudinal direction in the case 21. Further, the coil core portions 62a and 62b are disposed so as to sandwich the vibrating body 30 in the longitudinal direction of the case 21.

[0037] The coil core portions 62a and 62b are similarly configured in the present embodiment and are provided at positions symmetric about the axis of the shaft portion 40 in plan view.

[0038] The core portions 60a and 60b are magnetic bodies magnetized by energization of the coils 50a and 50b. The core portions 60a and 60b may be formed of, for example, electromagnetic stainless steel, sintered material, MIM (metal injection mold) material, laminated steel plate, electrogalvanized steel sheet (SECC), or the like. In the present embodiment, the core portions 60a and 60b are formed of a laminated core formed of a laminated steel plate.

[0039] The core portions 60a and 60b have cores 601a and 601b around which the coils 50a and 50b are wound, and magnetic poles (hereinafter, referred to as "core magnetic poles" for convenience) 602a, 603a, 602b, and 603b continuously formed at both ends of the cores 601a and 601b.

[0040] In the present embodiment, each of the core magnetic poles 602a, 603a, 602b, and 603b has a curved magnetic pole surface that is arcuate in plan view according to the magnetization surface shape of the reciprocally rotating magnets 70a and 70b.

[0041] The core poles 602a and 603a of the core part 60a face the magnet 70a, and the core poles 602b and 603b of the core part 60b face the magnet 70b. The core poles 602a, 603a, 602b, and 603b are arranged side by side in the rotational direction of the reciprocating rotation of the vibrating body 30.

[0042] The core poles 602a, 603a, 602b, and 603b are preferably arranged on the circumference of a circle centered on the shaft portion 40. This circumference is a circumference along the movement trajectories of the magnets 70a and 70b.

[0043] In the coil core parts 62a and 62b, the core poles 602a, 603a, 602b, and 603b of the core parts 60a and 60b around which the coils 50a and 50b are wound are arranged so as to face the magnetization directions of the magnets 70a and 70b.

[0044] The coils 50a and 50b are connected to a power supply unit (not shown), for example, in each of the core parts 60a and 60b. When the coils 50a and 50b are supplied with power from the power supply unit, the core poles 602a, 603a, 602b, and 603b are excited. In each of the core parts 60a and 60b, the core poles 602a, 602b and the core poles 603a, 603b are excited with different polarities.

[0045] <Vibrating body 30> As shown in FIGS. 3, 4, 6, and 7, the vibrating body 30 is arranged to extend in a direction (the longitudinal direction of the case 21) orthogonal to the shaft portion 40 (the rotation axis of the vibrating body 30) within the case 21 of the fixed body 20.

[0046] The vibrating body 30 is supported in the case 21 so as to be reciprocally rotatable about the shaft portion 40. The vibrating body 30 includes a vibrating body main body 32, a bearing portion 34, a pair of magnets 70a and 70b in which a plurality of magnetic poles (three poles in this embodiment) are alternately arranged in the rotational direction (the depth direction), and a pressing portion 35.

[0047] A bearing portion 34 is fixed to the vibrating body main body 32, and a shaft portion 40 is inserted through the bearing portion 34. A pair of magnets 70a and 70b are fixed to the vibrating body main body 32 so as to sandwich the shaft portion 40 inserted through the bearing portion 34.

[0048] The vibrating body main body 32 may or may not be a magnetic body (ferromagnetic body), and in this embodiment, it is a yoke and functions as a weight of the vibrating body 30. The vibrating body main body 32 is composed of, for example, laminated yoke cores. The constituent material of the vibrating body main body 32 is not limited to metal materials, and resin materials or the like may be used.

[0049] The vibrating body main body 32 has a central opening 322 in which a bearing portion 34 is fixed at the central portion, and arm portions 324a and 324b extending in opposite directions from this central portion. The arm portions 324a and 324b have an elongated flat plate shape, and the tip portions thereof protrude in a direction intersecting the extending direction. Further, magnet fixing portions 326a and 326b are formed on the tip surfaces of the arm portions 324a and 324b.

[0050] The tip surfaces of the magnet fixing portions 326a and 326b are formed to be curved in an arc shape, and the magnets 70a and 70b are fixed to these tip surfaces. Further, pressing portions 35 are provided on the arm portions 324a and 324b.

[0051] <Magnets 70a and 70b> The magnets 70a and 70b, together with coil core portions 62a and 62b arranged opposite to each other, constitute a magnetic circuit for driving the vibration actuator 10.

[0052] The magnets 70a and 70b have magnetic pole faces 72 that function as a plurality of magnetic poles, and the magnetic pole face 72 of the magnet 70a and the magnetic pole face 72 of the magnet 70b are arranged so as to sandwich the shaft portion 40 and face each other on opposite sides. In the present embodiment, the magnets 70a and 70b are provided at both end portions spaced apart in the extending direction of the vibrating body main body 32 through which the shaft portion 40 is inserted at the central portion, that is, at the tip portions of both arm portions 324a and 324b, such that the magnetic pole faces 72 face outward.

[0053] As shown in FIGS. 3-7 and 11, the magnetic pole face 72 includes three different magnetic poles 721, 722, and 723 arranged alternately. Note that the magnets 70a and 70b may be configured by alternately arranging different magnets (magnet pieces) of a plurality of magnetic poles, or may be magnetized so as to be arranged in the rotational direction and have alternately different magnetic properties. The magnets 70a and 70b are made of, for example, an Nd sintered magnet or the like.

[0054] The magnetic poles 721, 722, and 723 of the magnets 70a and 70b are arranged adjacent to each other in the depth direction orthogonal to the axis of the shaft portion 40, that is, in the rotational direction, with the shaft portion 40 interposed therebetween.

[0055] The magnets 70a and 70b are arranged such that the magnetic pole faces 72 are located on the circumferences of circles centered on the shaft portion 40 at both end portions of the vibrating body 30. When the magnets 70a and 70b are in a normal state, that is, in a non-energized state where no current is supplied to the coils 50a and 50b, the center position of the length in the rotational direction of the central magnetic pole 722 of each magnetic pole face 72 is located at the center position between the core magnetic poles 602a and 603a.

[0056] In the present embodiment, the magnets 70a and 70b are arranged to face, respectively, each of the coil core portions 62a and 62b provided on the inner surfaces of both end walls of the housing (case 21) at positions in the vibrating body 30 that are the most spaced apart from each other via the arm portions 324a and 324b from the shaft portion 40.

[0057] <Pressing portion 35> When the vibrating body 30 rotates and moves, the pressing portion 35 presses the movable walls 822 of the pair of sealed chambers 82 of the pump portion 80. Specifically, the pressing portion 35 has a pair of pressing members 351 that press the movable walls 822 of the pair of sealed chambers 82 when the arm portions 324a and 324b reciprocally rotate.

[0058] The pair of pressing members 351 of the pressing portion 35 are provided on the arm portions 324a and 324b so as to project in the width direction, that is, the rotation direction. The pressing portion 35 may be formed so as to linearly press the movable wall 822 in the opposing direction even when the vibrating body 30 rotates, for example. In the present embodiment, each pressing member 351 of the pressing portion 35 moves in an arc around the shaft portion 40 and contacts the movable wall 822 to press the movable wall 822. The pressing portion 35 may be configured in any manner as long as it is configured to be displaced toward the movable wall side as the vibrating body 30 rotates and moves, press the movable wall 822, and move the movable wall 822. It is desirable that the movable wall 822 be arranged so as to intersect the movement path of the pressing portion 35, and the moving pressing portion 35 be arranged so as to be in surface contact with the movable wall 822.

[0059] For example, as shown in FIG. 10, the pressing portion 35 is fixed to each of the arm portions 324a and 324b via a shaft protrusion 353 rotatably shaft-mounted in a round hole 328 and a guide protrusion 352 guided in a long hole 329. Thereby, the pressing member 351 swings in an arc as the vibrating body 30 reciprocally rotates. For example, the guide protrusion 352 may be loosely fitted in the long hole 329, and the pressing portion 35 may be made swingable with respect to the arm portions 324a and 324b by the guide protrusion 352, so that the tip of the pressing member 351 can swing. In this case, as the vibrating body 30 rotates, although the pressing portion 35 moves in an arc, it is possible to linearly move and press the pressing member 351 with respect to the movable wall 822.

[0060] In this embodiment, the pressing portion 35 is connected to the movable wall 822 of the pump portion 80 via the pusher 351. When the vibrating body 30 rotates and moves, the pusher 351 is inserted into the insertion portion 822a of the movable wall 822, which is a diaphragm, and presses and displaces the movable wall 822 in the rotational direction. When the vibrating body 30 rotates, the pressing portion 35 presses the movable wall 822 when it moves toward the movable wall 822 side. On the other hand, when the vibrating body 30 rotates in the reverse direction and the pressing portion 35 moves to the side opposite to the movable wall 822 side, the pressing force on the movable wall 822 is gradually decreased, and the movable wall 822 is displaced in the direction opposite to the pressing direction.

[0061] The bearing portion 34 is formed of, for example, a sintered sleeve bearing. The bearing portion 34 is fitted into the central opening 322 of the vibrating body main body 32 so that the shaft portion 40 is positioned on the central axis of the vibrating body main body 32.

[0062] When the coils 50a and 50b are not powered, the vibrating body main body 32 is biased by the function of the magnetic springs formed by the core portions 60a, 60 and the magnets 70a, 70b so as to be positioned at the center in the longitudinal direction within the case 21 (fixed body 20).

[0063] <Pump portion 80> Each of the pump portions 80 (80a, 80b) has a movable wall 822, a sealed chamber 82 defined by the movable wall 822, a suction portion 83, a valve 84, a discharge portion 86, and a discharge flow path portion 88.

[0064] <Movable wall 822> The movable wall 822 forms a partition wall that separates the chamber forming portion 824 and the discharge flow path portion 88, and is provided so as to be displaceable. The movable wall 822 changes the volume inside the sealed chamber 82 by being displaced by the vibration of the vibrating body 30. The movable wall 822 and the chamber forming portion 824 together form the sealed chamber 82.

[0065] The movable wall 822 is formed of, for example, an elastically deformable material and is provided so as to close the chamber forming portion 824. The movable wall 822 is, for example, a diaphragm.

[0066] The movable wall 822 has an insertion portion 822a into which the pusher 351 of the pressing portion 35 is inserted, and is connected to the pressing portion 35 via the insertion portion 822a. The movable wall 822 is pressed and displaced by the pressing portion 35 that moves as the vibrating body 30 rotates.

[0067] The movable wall 822 is elastically deformed by being pressed toward the chamber forming portion 824 by the pressing portion 35 via the insertion portion 822a, and is deformed so that the volume of the chamber forming portion 824 becomes smaller. The movable wall 822 is displaced toward the chamber forming portion 824 and protrudes into the chamber forming portion 824, whereby the volume in the sealed chamber 82 can be made variable.

[0068] Due to the forward rotational movement (oscillation to one side in the rotational direction) of the reciprocating rotation of the vibrating body 30, the movable wall 822 is inserted into the chamber forming portion 824, presses the inside of the chamber forming portion 824, reduces the volume in the sealed chamber 82, and discharges air. On the other hand, when the vibrating body 30 makes a reverse rotational movement (movement to the other side in the rotational direction), the movable wall 822 increases the volume in the sealed chamber 82 and allows air to flow in.

[0069] <Sealed chamber 82> The sealed chamber 82 is a sealed space to which the suction portion 83 and the discharge portion 86 are connected and whose volume is changed by the displacement of the movable wall 822. The discharge portion 86 has a discharge port communicating with the outside, and discharges air from the pump 1 to the outside through the discharge port. For example, the discharge port is an opening communicating with the discharge portion 86 connected to the bottom surface of the sealed chamber 82. When the movable wall 822 is displaced, the volume in the sealed chamber 82 is changed, and air is inhaled into the sealed chamber 82 or air is discharged from the sealed chamber 82 to the outside. The discharge portion 86 fluidly communicates the tank portion 120 and the sealed chamber 82.

[0070] In the pump unit 80, when the movable wall 822 is pressed by the pressing portion 35, the movable wall 822 elastically deforms toward the sealed chamber 82 and presses the air in the sealed chamber 82. The air in the pressed sealed chamber 82 is discharged to the outside through the discharge portion 86. When the movable wall 822 moves so as to return to its original position, that is, when the pressing state by the pressing portion 35 is released and the volume in the sealed chamber 82 increases from the pressed state, air is inhaled into the sealed chamber 82 from the outside through the suction portion 83. For example, the suction portion 83 has a suction port and inhales air into the sealed chamber 82 through the suction port. For example, the suction port is an opening that communicates with the suction portion 83 in the chamber forming portion 824.

[0071] The pump units 80 (80a, 80b) are respectively arranged in the case 21 along the extending direction of the vibrating body 30, that is, along the side wall portion extending in the longitudinal direction of the case 21. Further, the pump units 80 (80a, 80b) are arranged in the depth direction of the case 21 so as to sandwich the vibrating body main body 32 of the vibrating body 30.

[0072] The pump unit 80 has, for example, a base 801, a diaphragm portion 802, a cylinder portion 803, a valve portion 804, a valve cover portion 805, a partition portion 806, and a flow path forming portion 807. The base 801, the diaphragm portion 802, the cylinder portion 803, the valve portion 804, the valve cover portion 805, the partition portion 806, and the flow path forming portion 807 each have an elongated plate shape extending in the longitudinal direction of the case 21, and constitute the pump unit 80 having an internally sealed space formed by being laminated.

[0073] The base 801 has an opening, and an insertion portion 822a of the diaphragm portion 802 is inserted through the opening from the back side and is arranged in a state where the insertion portion 822a protrudes to the front side. The base 801, together with the flow path forming portion 807, constitutes the housing of the strip-shaped pump portion 80. The diaphragm portion 802 is formed of an elastic material such as rubber. The diaphragm portion 802 has an insertion portion 822a and a movable wall 822. On the back side of the movable wall 822 that is flexible and elastically deformable, a chamber forming portion 824 of the cylinder portion 803 is arranged. The diaphragm portion 802 and the cylinder portion 803 are attached to each other such that a sealed chamber 82, which is a sealed space, is formed by the movable wall 822 of the diaphragm portion 802 and the chamber forming portion 824 of the cylinder portion 803.

[0074] The cylinder portion 803 has a chamber forming portion 824. In the sealed chamber 82, two communication holes that communicate with the discharge portion 86 and the suction portion 83 respectively are formed on the surface facing the movable wall 822. The two communication holes are connected to the discharge flow path portion 88 of the valve cover portion 805 and the flow path forming portion 807 and the suction portion 83 respectively via valves 84 of the valve portion 804 that are attached so as to overlap the communication holes from the back side of the cylinder portion 803.

[0075] The valve portion 804 is attached to the valve cover portion 805. The valve 84 connected to the discharge portion 86 is configured to communicate with the discharge portion 86 of the flow path forming portion 807 when the volume in the sealed chamber 82 decreases. On the other hand, the valve 84 connected to the discharge portion 86 is configured to be closed when the volume in the sealed chamber 82 increases. The valve 84 connected to the suction portion 83 is configured to be closed when the volume in the sealed chamber 82 decreases. On the other hand, the valve 84 connected to the suction portion 83 is configured to communicate with the suction portion 83 of the flow path forming portion 807 when the volume of the sealed chamber 82 increases.

[0076] In this embodiment, each of the pump units 80 (80a, 80b) has a pair of sealed chambers 82 composed of a movable wall 822 and a chamber forming portion 824. Each of the pump units 80 (80a, 80b) is arranged such that its pair of sealed chambers 82 faces the respective side surfaces of the arm portions 324a, 324b that sandwich the shaft portion 40 and extend in opposite directions from each other. That is, the pump units 80 (80a, 80b) are arranged such that the pair of sealed chambers 82 of the pump units 80 (80a, 80b) face each other at a position where the arm portions 324a, 324b are sandwiched in the direction in which the arm portions 324a, 324b reciprocally rotate.

[0077] FIGS. 10A and 10B are diagrams showing the air discharge and suction operations in the pump of the pump control system according to the first embodiment of the present invention.

[0078] As shown in FIG. 10A, when the pressing portion 35 moves toward the movable wall 822, the pusher 351 abuts against and presses the movable wall 822 via the insertion portion 822a. As a result, the movable wall 822 is displaced toward the chamber forming portion 824 side, and the air in the sealed chamber 82 is pressed and compressed. The compressed air flows through the open valve 84 to the only communicating discharge portion 86 side (see the white arrow in FIG. 10A).

[0079] On the other hand, as shown in FIG. 10B, when the pressing portion 35 makes a reverse rotational movement, that is, retreats from the pump unit 80 side, the movable wall 822 elastically restores following the pressing portion 35, and the volume in the sealed chamber 82 restores, that is, increases. At this time, the valve 84 connected to the discharge portion 86 is tightened to block the discharge path, while the valve 84 connected to the suction portion 83 is in an open state, and air is sucked into the sealed chamber 82 through the suction portion 83 (see the white arrow in FIG. 10B).

[0080] <Magnetic Circuit Configuration> In this embodiment, as shown in FIGS. 3 and 7, within the case 21, core portions 60a and 60b, which are magnetic bodies, are arranged to face each other so as to be spaced apart in the longitudinal direction and face the magnets 70a and 70b respectively disposed at both end portions of the vibrator 30 facing each other with the vibrator shaft portion 40 interposed therebetween. The core portions 60a and 60b are respectively disposed on the inner surfaces of both end wall portions in the longitudinal direction of the case 21 so as to be spaced apart in the longitudinal direction and face each other.

[0081] Magnetic attractive forces are respectively generated between the core portion 60a and the magnet 70a, and between the core portion 60b and the magnet 70b. The two magnetic attractive forces generated in the longitudinal direction (the extending direction of the arm portions 324a and 324b) sandwich the shaft portion 40, are on the same straight line with each other, and are generated in opposite directions, so they cancel each other out.

[0082] FIG. 11 is a diagram showing the magnetic spring of the pump of the pump control system according to the first embodiment of the present invention. In the pump 1, the magnetic circuit provided by the coil core portion 62a and the magnet 70a and the magnetic circuit provided by the coil core portion 62b and the magnet 70b are configured to be point-symmetrical about the shaft portion 40. Therefore, in FIG. 11, only the magnetic circuit provided by the coil core portion 62a and the magnet 70a will be described, and the description of the magnetic circuit provided by the coil core portion 62b and the magnet 70b will be omitted.

[0083] In FIG. 11, the magnet 70a has a configuration in which the magnetic poles 721, 722, and 723 are N pole, S pole, and N pole respectively on the magnetic pole surface 72 facing the core portion 60a. Each of the magnetic poles 721 to 723 on the magnetic pole surface 72 of the magnet 70a attracts the adjacent core magnetic poles 602a and 603a.

[0084] The central magnetic pole 722 of the magnet 70a attracts both of the core magnetic poles 602a and 603a. The magnetic pole 721 of the magnet 70a attracts the core magnetic pole 602a, and the magnetic pole 723 of the magnet 70a attracts the core magnetic pole 603a. As a result, the magnetic pole 722 at the center of the magnet 70a is located at the center of the coil core portion 62a, that is, between the core magnetic poles 602a and 603a.

[0085] In the pump 1, when an electric current flows through the coil 50a of the coil core portion 62a, the core magnetic poles 602a and 603a of the core portion 60a are excited with different polarities. As a result, a thrust force is generated on the vibrating body 30 according to the relationship with the magnet 70a arranged opposite to the coil core portion 62a. The same applies to the magnetic circuit provided by the coil core portion 62b and the magnet 70b. Therefore, by periodically changing the direction of the electric current supplied to the coils 50a and 50b, the vibrating body 30 provided with the magnets 70a and 70b rotates in a reciprocating motion (rotary reciprocating vibration) in the rotational direction about the shaft portion 40.

[0086] <Operation of Pump 1> An example of the operation will be described with reference to FIG. 12. FIG. 12 is a diagram showing the magnetic circuit configuration of the pump of the pump control system 100 according to the first embodiment of the present invention. In the description of an example of the operation of the pump 1 with reference to FIG. 12 as well, similar to the description with reference to FIG. 11, only the magnetic circuit provided by the coil core portion 62a and the magnet 70a will be described, and the description of the magnetic circuit provided by the coil core portion 62b and the magnet 70b will be omitted.

[0087] The magnet 70a shall have three-polarity magnetic poles arranged alternately in the rotational direction of the vibrating body 30 on the magnetic pole surface 72. In the magnet 70a shown in FIG. 12, on the magnetic pole surface 72 facing the core portion 60a, the central magnetic pole 722 is an S pole, and the magnetic poles 721 and 723 sandwiching the central magnetic pole 722 are each an N pole.

[0088] Then, as shown in FIG. 12, when a current is supplied to the coil 50a of the coil core portion 62a to excite the core portion 60a, the core magnetic pole 602a of the core portion 60a is magnetized to the S pole and the core magnetic pole 603a is magnetized to the N pole.

[0089] As shown in FIG. 12, since the magnetic pole 723 of the magnet 70a facing the core magnetic pole 603a that becomes the N pole is the N pole, it repels the core magnetic pole 603a that becomes the N pole. Also, since the magnetic pole 722 of the magnet 70a is the S pole, a magnetic attractive force is generated between it and the core magnetic pole 603a that becomes the N pole, while it repels the core magnetic pole 602a that becomes the S pole. Further, since the magnetic pole 721 of the magnet 70a is the N pole, a magnetic attractive force is generated between it and the core magnetic pole 602a that becomes the S pole.

[0090] As a result, a thrust in the F1 direction is generated between the magnet 70a and the coil core portion 62a, and the vibrating body 30 is driven in the F1 direction. When the coil 50a is not energized, the vibrating body 30 is positioned at the rotational reference position and the neutral position during reciprocating motion due to the magnetic attractive force of the magnetic spring.

[0091] Also, when a current is supplied to the coil 50a in the reverse direction to reverse the polarity of the core portion 60a, that is, to make the magnetic pole 603a of the core portion 60a facing the magnet 70a the S pole and the magnetic pole 602a the N pole. As a result, the magnet 70a facing the core portion 60a rotates and moves in the direction opposite to the F1 direction (-F1 direction). The vibrating body 30 is driven in the -F1 direction, which is exactly opposite to the F1 direction.

[0092] In the vibrating body 30, the relationship between the magnet 70b disposed on the opposite side of the magnet 70a with respect to the shaft portion 40 and the coil core portion 62b is point-symmetrical about the shaft portion 40 with respect to the relationship between the magnet 70a and the coil core portion 62a. Therefore, a thrust in the F1 direction or -F1 direction is similarly generated between the magnet 70b and the coil core portion 62b, just as between the magnet 70a and the coil core portion 62a. As a result, due to the magnetic attractive force and repulsive force effectively generated in the magnetic circuits at both ends of the vibrating body 30, the vibrating body 30 suitably rotates and reciprocates about the shaft portion 40.

[0093] The driving principle is shown below. In the vibration actuator 10, when the moment of inertia of the vibrating body 30 is J [kg·m 2 , and the spring constant in the rotational direction is K sp , the vibrating body 30 vibrates with respect to the fixed body 20 at a resonance frequency f r [Hz] calculated by the following formula (1).

[0094]

Equation

[0095] The pump 1 supplies an alternating current with a frequency approximately equal to the resonance frequency f r of the vibrating body 30 to the coils 50a, 50b, and excites the core parts 60a, 60b (specifically, the core poles 602a, 603a, 602b, 603b) through the coils 50a, 50b. Thereby, the vibrating body 30 can be efficiently driven.

[0096] The vibrating body 30 in the vibration actuator 10 is supported in a state of a spring-mass system structure constituted by a magnetic spring provided by coil-core parts 62a, 62b each having coils 50a, 50b and core parts 60a, 60b and magnets 70a, 60b. Therefore, when an alternating current with a frequency equal to the resonance frequency f r of the vibrating body 30 is supplied to the coils 50a, 50b, the vibrating body 30 is driven in a resonance state.

[0097] The equations of motion and circuit equations showing the driving principle of the vibration actuator 10 are shown below. The vibration actuator 10 is driven based on the equation of motion shown by the following formula (2) and the circuit equation shown by the following formula (3).

[0098]

Equation

[0099]

Equation

[0100] That is, the moment of inertia J [kg·m 2 of the vibrating body 30 in the vibration actuator 10 of the pump 1, the displacement angle (rotation angle) θ(t) [rad], the thrust constant (torque constant) K f [Nm / A], the current i(t) [A], the spring constant K sp [Nm / rad], the damping coefficient D [Nm / (rad / s)], etc. can be appropriately changed within the range that satisfies Equation (2). Also, the voltage e(t) [V], the resistance R [Ω], the inductance L [H], and the back electromotive force constant K e [V / (m / s)] can be appropriately changed within the range that satisfies Equation (3).

[0101] Thus, in the vibration actuator 10 of the pump 1, when energizing the coils 50a and 50b with an alternating current corresponding to the resonance frequency f sp determined by the moment of inertia J of the vibrating body 30 and the spring constant K of the magnetic spring r , a large vibration output can be efficiently obtained.

[0102] Note that in the pump 1, when the vibrating body 30 reciprocates and rotates, the volume in the sealed chamber 82 changes due to the displacement of the movable wall 822 of the pump section 80 (specifically, the deformation of the diaphragm), and it functions as a pump. In the following, the function as this pump has the flow rate set by the following Equation (4) and the pressure set by the following Equation (5).

[0103]

Equation

[0104]

Equation

[0105] That is, the flow rate Q [L / min] in the pump 1, the piston area A [m 2, the piston displacement x [m], the driving frequency f [Hz], etc. can be appropriately changed within the range that satisfies Equation (4). Also, the increased pressure [kPa], the atmospheric pressure P0 [kPa], the sealed chamber volume V [m 3 , the variable volume ΔV [m 3 = the piston area [m 2 A * the piston displacement [m] can be appropriately changed within the range that satisfies Equation (5).

[0106] Thus, the pump 1 of this embodiment has an electromagnetic drive vibration actuator 10 and a pump section 80 (80a, 80b) that inhales and discharges air by the electromagnetic drive of the vibration actuator 10. In the vibration actuator 10, the fixed body 20 includes one of a coil core section 62a having a coil 50a and a core 60a around which the coil 50a is wound, and a magnet 70a disposed opposite to an end of the core 60a. Further, the pump section 80 is provided on the fixed body 20. The vibrating body 30 includes the other of the coil core section 62a and the magnet 70a, and is elastically held by the magnetic attraction force of the magnet 70a. The shaft section 40 supports the vibrating body 30 so as to be reciprocally rotatable. The pump section 80 has a movable wall 822 that moves by the rotational movement of the vibrating body 30, and a sealed chamber 82 that communicates with the air discharge port 86 and the air suction port 83 and whose volume is changed by the displacement of the movable wall 822. The vibrating body 30 has a pressing section 35 that moves in an arc shape about the shaft section 40 as the vibrating body 30 reciprocally rotates and abuts against and presses the movable wall 822. The movable wall 822 is disposed in the moving direction of the pressing section 35, and is displaced when pressed by the pressing section 35 to discharge the air in the sealed chamber 82 through the discharge port 86.

[0107] <Tank section 120> Returning to FIG. 1, the tank unit 120 adjusts the pressure of the fluid discharged from the pump unit 1. Specifically, the tank unit 120 stores the air discharged from the sealed chamber 82 of the pump 1 and increases the pressure of the air discharged from the tank unit 120. The tank unit 120 is connected to the tank discharge path and stores the air discharged from within the closed chamber 82 without outputting it to the outside, thereby storing air within the tank unit 120 and making it possible to adjust the pressure within the tank unit 120. The tank unit 120 is connected to the discharge port 86 of the pump 1 and is in fluid communication with the sealed chamber 82 of the pump 1 (pump unit 80).

[0108] The fluid discharged from the pump 1 (pump unit 80), which is air in this embodiment, is supplied into the tank unit 120. The tank unit 120 stores the supplied fluid, increases the pressure of the fluid within the tank unit 120, and may be appropriately discharged at a desired pressure. The tank unit 120 may be any device as long as it has a capacity sufficient to store air and increase the pressure of the fluid discharged from the tank unit 120, and may use the supplied air, for example, it may be a cuff of a sphygmomanometer or the like.

[0109] <Pressure measurement unit 130> The pressure measurement unit 130 measures the state of the air (fluid) within the tank unit 120. Specifically, the pressure measurement unit 130 measures the pressure of the air (fluid) within the tank unit 120, obtains pressure value information indicating the value of the pressure, and outputs the pressure information to the microcomputer unit 140. The pressure measurement unit 130 may be configured in any manner as long as it can measure the pressure of the air (fluid) within the tank unit 120. The pressure measurement unit 130 may be provided on the tank unit 120 or may be provided within the tank unit 120.

[0110] <Microcomputer unit 140> The microcomputer unit 140 includes an acquisition unit 146, an output unit 144, and a storage unit 142. The acquisition unit 146 acquires the value of the pressure of the air in the tank unit 120 based on the pressure information input from the pressure information measurement unit 130. The acquisition unit 146 is connected to the pressure measurement unit 130 and acquires the measured pressure value of the air in the tank unit 120 based on the pressure information input from the pressure measurement unit 130. The output unit 144 has a function of outputting a drive frequency to the coils 50a and 50b. The output unit 144 outputs a drive frequency based on the information of the pressure value of the air in the tank unit 120 acquired by the acquisition unit 146 to the coils 50a and 50b of the pump 1.

[0111] The microcomputer unit 140 has a function as a control unit and changes the vibration of the vibration actuator of the pump 1 based on the measured pressure value of the air in the tank unit 120. The microcomputer unit 140 acquires the pressure value of the air in the tank unit 120, here the measured pressure value, as pressure value information, and controls the drive frequency of the current supplied to the coils 50a and 50b based on the acquired pressure value information.

[0112] The microcomputer unit 140 changes the frequency of the drive signal output to the pump 1 to change the pressure of the air in the tank unit 120. The microcomputer unit 140 controls the drive frequency so that currents of the resonance frequencies of different vibrating bodies 30 are supplied to the coils 50a and 50b according to the pressure of the air in the tank unit 120.

[0113] The microcomputer unit 140 controls, for example, to store air in the tank unit 120 so that the pressure of the air in the tank unit 120 becomes a desired pressure by referring to a look-up table stored in the built-in ROM used as the storage unit 142. As the look-up table, a table or the like for associating the drive frequency with the pressure value of the air in the tank unit 120 and switching the drive frequency according to the pressure value of the air in the tank unit 120 can be used.

[0114] The microcomputer unit 140 switches the drive frequency supplied to the coils 50a and 50b between a first drive frequency that maximizes the air flow rate from the pump 1 to the tank unit 120 (see G2 in FIG. 14) and a second drive frequency that maximizes the air pressure in the tank unit 120 (see G1 in FIG. 14).

[0115] Also, the microcomputer unit 140 switches the drive frequency from the first drive frequency (see H1 in FIG. 14) to the second drive frequency (see H2 in FIG. 14) in the process of increasing the air pressure in the tank unit 120. The pressure value at the timing of switching the drive frequency in the process of increasing the air pressure in the tank unit 120 is also referred to as a process value for convenience. Thereby, the air pressure in the tank unit 120 can be increased more efficiently in a shorter time than when controlled at the first drive frequency (see H1 in FIG. 14). The microcomputer unit 140 controls each part according to a program stored in a ROM or the like. Thereby, for example, a drive signal of a drive frequency changed based on the acquired air pressure value information in the tank unit 120 can be supplied to the coils 50a and 50b of the pump 1 to control the pump 1.

[0116] When driving the vibrating body 30 of the resonant type vibration actuator 10 of the pump 1, the pump control system 100 of the present embodiment changes the frequency of the drive signal for driving the vibrating body 30 based on the pressure in the tank unit 120, and supplies a drive signal of a frequency corresponding to the air pressure in the tank unit 120 to the coils 50a and 50b of the pump 1.

[0117] <Operating principle of the pump 1 by the microcomputer unit 140 (control unit)> The pump 1 needs to ensure the required flow rate of the fluid (air) to be conveyed and the magnitude of the pressure (air pressure) to the fluid to be conveyed.

[0118] Generally, in a configuration in which a tank is connected to a resonant type vibration actuator, it is known that a phenomenon occurs in which the resonant frequency changes according to a change in the air pressure in the tank.

[0119] FIG. 13 is a diagram showing the operating principle of pump 1 of the pump control system 100. FIG. 13A is a conceptual diagram showing a state in which the discharge path of the pump is open, such as when the tank section is not connected to the discharge port (corresponding to the discharge section 86). FIG. 13B is a conceptual diagram showing a state in which the discharge path of the pump is closed by attaching a tank to the discharge port of the pump.

[0120] As shown in FIG. 13A, when the discharge path of the resonantly driven pump is open (also referred to as "when the pump is open"), when the pump vibrates, that is, when the movable wall is displaced by driving the pump section, the air discharged from the sealed chamber is discharged outside the pump through the discharge port. On the other hand, as shown in FIG. 13B, when a tank section (corresponding to the tank section 120) is connected to the resonantly driven pump and the discharge path to the outside of the pump is blocked (also referred to as "when the pump is closed"), the air in the tank section acts on the vibration of the pump. This is due to the fact that the sealed chamber and the tank section are in fluid communication via the discharge port (corresponding to the discharge section 86).

[0121] That is, at the beginning of the increase in the pressure in the tank section, the air discharged from pump 1 is directly supplied into the tank section, so it shows behavior similar to when the pump is open. On the other hand, when the pressure in the tank section increases, there is no escape path for the air supplied from pump 1, so the air supplied from pump 1 is stored in the tank section (the air flow is indicated by a thick white arrow).

[0122] The air inside the tank that is in fluid communication with the closed chamber acts on the pump 1 (more specifically, the pump section 80 and the vibrator 30) via the supplied air and acts as an air spring in the pump 1. Thus, when the tank section is attached to the discharge port of the pump 1, during pump closed circuit operation, the action of the air spring works compared to the state during pump open circuit operation. Therefore, the resonance frequency f during pump open circuit operation represented by the following formula (6) becomes the resonance frequency f' during pump closed circuit operation represented by the following (7). That is, during pump closed circuit operation, when the pressure inside the tank section 120 increases due to the drive of the pump 1, the springiness also increases, and the resonance frequency of the pump actuator becomes higher than during pump open circuit operation.

[0123]

Number

[0124]

Number

[0125] Based on the above, the pump control system 100 has the frequency characteristics of the air pressure in the tank shown in Fig. 14 and the air flow rate from the tank. Fig. 14 is a diagram showing the frequency characteristics of the air pressure in the tank when the pump is open and when the pump is closed using the resonance type pump of the present embodiment. As shown in Fig. 14, in the case of a resonance type pump, the maximum value of the air pressure G1 in the tank at the time of closed circuit and the air pressure G2 (hereinafter, since G2 represents the air flow rate from the pump into the tank, it is referred to as the flow rate G2) representing the air flow rate from the pump to the tank at the time of open circuit at each driving frequency is realized by driving in different resonance frequency bands (near the resonance points H1 and H2). For example, in the case of a resonance type pump that is resonance-driven at the driving frequency H1 (the first driving frequency H1), at the time of open circuit, if it is driven at the driving frequency H1 (the first driving frequency H1), the flow rate G2 increases (the maximum value in the figure). However, at the time of closed circuit, since the air acts on the vibrating body 30 as a spring, the resonance point of the vibrating body 30 of the pump shifts (in Fig. 14, the resonance point shifts to H2), and the pressure G1 becomes difficult to increase. On the other hand, taking into account the shift of the resonance point, if it is resonance-driven at a frequency (the second driving frequency H2) near the driving frequency H2, which is higher than the driving frequency H1, the pressure G1 increases, but it is used at a resonance frequency where the flow rate G2 is difficult to output. Thus, in a product that requires a desired pressure in the tank portion 120, such as a sphygmomanometer as an example, when resonance driving is performed at a single frequency, it is necessary to drive at a frequency that is disadvantageous in either the flow rate or the pressure.

[0126] To utilize this characteristic, in the pump control system 100 of the present embodiment, when the microcomputer unit 140 (control unit) increases the pressure in the tank portion 120 having a predetermined capacity until it reaches a predetermined pressure value, it changes the driving frequency. Specifically, the microcomputer unit 140 changes the driving frequency by switching the driving frequency between the first driving frequency H1 that maximizes the air flow rate G2 from the pump 1 to the tank portion 120 and the second driving frequency H2 that maximizes the air pressure G1 in the tank portion 120.

[0127] FIG. 15 is a diagram showing an example of frequency control in the pump control system 100 according to an embodiment of the present invention.

[0128] In the pump control system 100, the microcomputer unit 140 supplies air (fluid) into the tank unit 120 and increases the pressure of the air in the tank unit 120 until the pressure of the air in the tank unit 120 reaches a desired pressure.

[0129] The desired pressure (value) varies appropriately depending on the application target of the pump control device and the pump control system 100 of the present embodiment. For example, when the pump control system 100 (pump control device) is applied to a sphygmomanometer, according to the hypertension treatment guidelines (JSH2004), hypertension is defined as 18 kPa (135 mmHg) or higher, and according to the JIS standard (T115) for non-invasive automatic blood pressure monitors, it must not exceed 40 kPa. The desired pressure value is set based on these. It may be set to 40 kPa and be changeable from 18 kPa to 40 kPa. Hereinafter, with reference to FIG. 15, when the tank capacity is a constant volume (for example, 500 cc) and the pump control system 100 increases the pressure of the tank unit 120 to 40 kPa, the case will be described in detail.

[0130] In this case, the microcomputer unit 140 supplies a drive signal having a frequency with a rapid increase from pressure 0, that is, a frequency with a high degree of increase in which the pressure rises from 0, to the coils 50a and 50b. More specifically, the lower frequency of the first drive frequency H1 and the second drive frequency H2 (denoted as H1 as in FIG. 14), that is, the drive signal of the first drive frequency H1, is input to the coils 50a and 50b for excitation.

[0131] FIG. 15 shows the relationship between the pressure and the pressure increase time during driving at the first driving frequency H1 and driving at the second driving frequency H2 (>H1) (indicated by H2 in the same manner as the frequency indicated by H2 in FIG. 14). Then, the microcomputer unit 140 switches from the process at the first driving frequency H1 to the process at the second driving frequency H2 at a predetermined switching timing. This switching timing is changed based on the pressure state of the air in the tank unit 120. The timing when the slope indicating the increase in the pressure value of the air in the tank unit 120 becomes gentle is indicated by "frequency switching" in FIG. 15. At this gentle timing, the driving frequency is changed from the first driving frequency H1 to the second driving frequency H2. Thereby, at the time of startup (when the pump 1 is started), the pump 1 is driven by the driving signal of the first driving frequency H1 at which the pressure of the air in the tank unit 120 increases rapidly, and at the timing when the slope indicating the increase in the pressure of the air in the tank unit 120 becomes gentle (the "frequency switching" in FIG. 15) with the driving signal of the first driving frequency H1, the driving frequency is changed from the first driving frequency H1 to the second driving frequency H2. In this way, the characteristic due to shifting the driving frequency from the first driving frequency H1 to the second driving frequency H2 is indicated by K1 in FIG. 15.

[0132] Specifically, different frequencies (for example, the first driving frequency H1 and the second driving frequency H2) are compared, and the coils 50a and 50b are excited and the vibrating body 30 is resonantly driven at the first driving frequency at which the pressure value at the timing of rising from 0 and switching the driving frequency, that is, the pressure increase time up to the process value (about 10 kPa) is short. In the resonant driving at the first driving frequency H1, the pressure increase time of the air in the tank unit 120 is short up to about 10 kPa. However, if the resonant driving at the first driving frequency H1 is continued, the pressure in the tank unit 120 does not increase up to the desired pressure value (for example, 40 kPa).

[0133] Also, when resonance driving is performed at a second driving frequency H2 that is higher than the first driving frequency H1, although the pressure of the air in the tank unit 120 can exceed a desired high pressure (for example, 40 kPa), compared to when resonance driving is performed at the first driving frequency H1, the pressure increase time of the air in the tank unit 120 from 0 to the process value (about 10 kPa) is long. Therefore, in the present embodiment, resonance driving of the pump 1 is started with a driving signal having the first driving frequency H1, and at a predetermined switching timing, for example, at 10 KPa, the driving frequency of the driving signal is changed to the second driving frequency H2. Thereby, the pump 1 can be driven with the characteristic K1 shown in FIG. 15.

[0134] Thereby, compared with resonance driving at a single frequency (the second driving frequency H2), it becomes possible to increase the pressure in a shorter time. Specifically, in FIG. 15, the characteristic curve of the characteristic K1 can achieve a desired high pressure (for example, 40 kPa) in a shorter time than the characteristic curve (the graph indicated by the dotted line in FIG. 15) when resonance driving is performed only at the second driving frequency H2.

[0135] FIG. 16 is a diagram showing an example of the control flow of the pump according to the embodiment of the present invention. As shown in FIG. 16, first, in step S11, the drive frequency of the drive signal of the pump control system 100 is set to drive frequency 1 (first drive frequency H1). In step S12, the microcomputer unit 140 measures the pressure in the tank unit 120 by the pressure measurement unit 130, and the acquisition unit 146 acquires it as the pressure value of the air in the tank unit 120. In step S13, the microcomputer unit 140 determines whether the acquired air pressure value is the switching pressure value (process value), and repeats the determination until the acquired air pressure value becomes the switching pressure value. That is, in step S13, the drive frequency of the current supplied to the coils 50a and 50b is switched between the first drive frequency H1 that maximizes the flow rate G2 of air (fluid) from the pump 1 to the tank unit 120 and the second drive frequency H2 that maximizes the pressure G1 of air (fluid) in the tank unit 120. In step S13, if the pressure value has reached the switching pressure value, the process proceeds to step S14, and the drive frequency of the current supplied to the coils 50a and 50b is set to drive frequency 2 (second drive frequency H2).

[0136] Next, the microcomputer unit 140 measures the pressure of the air in the tank unit 120 (step S15), and determines whether it is the required pressure, that is, whether the desired pressure value has been reached (step S16), and repeats this until the desired pressure value is reached.

[0137] This embodiment is different from, for example, frequency response measurement using driving at each single frequency (a series of measurement processes in which driving is performed at each set driving frequency, and when the pressure due to the driving is the maximum pressure value, it is determined whether the current driving frequency is the required driving frequency). That is, according to this embodiment, unlike frequency response measurement, there is no control to output the maximum pressure at each set driving frequency, and the control time does not increase. According to this embodiment, the pump can be miniaturized, and more suitable pump pressure and flow rate can be ensured, and stable driving can be achieved. In particular, in a pump using a resonant type vibration actuator, the pressure of the air in the tank unit 120 can be increased in a shorter time compared to driving at a single frequency.

[0138] (Second Embodiment) FIG. 17 is a block diagram showing a schematic configuration of a pump according to a second embodiment of the present invention. The pump control system 100A shown in FIG. 17 uses a timer 160 instead of the pressure detection unit 130 (see FIG. 1) as compared with the pump control system 100.

[0139] Since the basic configuration of the pump control system 100A according to the second embodiment is the same as the basic configuration of the pump control system 100 of the first embodiment, only the different configurations will be described, and for the same configurations, the same reference numerals and names will be given and the description will be omitted.

[0140] The pump control system 100A includes a pump 1, a tank unit 120, a microcomputer unit 140A, and a timer 160.

[0141] The timer 160 measures the driving time of the vibrator 30 when increasing the pressure of the air (fluid) in the tank unit 120 to obtain the driving time of the vibrator 30. The acquisition unit 146 acquires the driving time of the vibrator 30. When the acquisition unit 146 acquires the driving time of the vibrator 30 from the timer 160, pressure value information is acquired from the driving time of the vibrator 30. In this embodiment, this pressure value information is a table showing the relationship between the preset driving time of the vibrator 30 and the pressure of the air in the tank unit 120 that increases by driving for this driving time, and is stored in the storage unit 142. This table is, for example, a timing table showing the timing for switching the driving frequency of the current supplied to the coils 50a and 50b from the first driving frequency H1 to the second driving frequency H2 in the process of increasing the pressure of the air in the tank unit 120.

[0142] The microcomputer unit 140A operates each unit using the table in the storage unit 142. In particular, based on the table acquired as pressure value information by the acquisition unit 146, it controls the drive frequency of the current supplied to the coils 50a and 50b. Thus, in the pump control system 100A, without measuring the pressure in the tank unit 120, the microcomputer unit 140A acquires, with the timer 160, the pressure increase time during which the pressure of the air in the tank unit 120 is increasing, that is, the drive time of the vibrating body 30, and the acquisition unit 146 acquires pressure value information indicating a value corresponding to the pressure. Based on the acquired information, the microcomputer unit 140A controls the drive frequency of the current supplied to the coils 50a and 50b.

[0143] Thereby, the microcomputer unit 140A can set the frequency switching time (timing) when controlling the drive frequency of the current supplied to the coils 50a and 50b, and can perform the same operation as the microcomputer unit 140. An example of the operation of the microcomputer unit 140A will be described with reference to FIG. 15. In FIG. 15, when driven at the first drive frequency H1, the pressure becomes difficult to increase at the stage where about 5 seconds have elapsed (the position indicated by "frequency switching" in FIG. 15). A timing table indicating such a frequency switching position may be stored in the storage unit 142 as pressure value information.

[0144] Based on the pressure value information stored in the storage unit 142, that is, the timing table indicating the frequency switching position, the microcomputer unit 140A performs control to switch the drive frequency of the current supplied to the coils 50a and 50b from the first drive frequency H1 to the second drive frequency H2 5 seconds after the start of pressure increase. Thereby, the microcomputer unit 140A can control the drive frequency of the current supplied to the coils 50a and 50b so as to obtain the characteristic K1 shifted from the first drive frequency H1 to the second drive frequency H2, similar to the case of using the pressure value detected by the pressure detection unit 130.

[0145] <Switching Pattern 1> FIG. 18 and FIG. 19 are diagrams showing patterns of drive frequency control of currents supplied to coils 50a and 50b when the tank capacities are different. FIG. 20 is a table showing the case where the drive frequency is switched based on the pressure value using the pump of the first embodiment. FIGS. 21A and 21B are tables showing the case where the drive frequency is switched with time using the pump of the second embodiment. In each figure, the initial drive frequencies corresponding to different pressures and flow rates are 150 Hz, 250 Hz, and 270 Hz, but this is an example, and as long as there are a plurality of different frequencies, the high and low are not limited.

[0146] The characteristics K2 and K3 shown in FIGS. 18 and 19 are the characteristics when the frequency in the "frequency band (region) where the flow rate is easily output" is used in the characteristics of a resonant type actuator whose characteristics are different when the pump is open and when the pump is closed (see FIG. 14).

[0147] The pump control system 100 of the first embodiment performs the drive frequency control shown in FIGS. 18 and 19 using the table of FIG. 20 based on the pressure value in the tank unit 120 measured by the pressure measurement unit 130. In FIGS. 18 and 19, when controlling the drive frequency of the drive signal to be frequency-shifted to become the characteristics K2 and K3, the drive frequencies of the currents supplied to the coils 50a and 50b are changed twice, and the increase time of the pressure in the tank unit 120 is shortened. The two changes in the drive frequency are both between the drive frequency that maximizes the air flow rate G2 and the drive frequency that maximizes the air pressure G1 during the process of increasing the pressure of the air in the tank unit 120, and are performed by switching the drive frequencies of the currents supplied to the coils 50a and 50b.

[0148] In FIG. 20, as an example of the initial drive frequency, three different frequencies [Hz] are associated with the pressure of the fluid in the tank unit 120 ("target pressure") when switching to those frequencies. Thereby, regardless of the tank capacity, the pump control system 100 can increase the air in the tank unit 120 more quickly (see the arrows indicating the shortening of the increase time in FIGS. 18 and 19) and effectively than driving the air in the tank unit 120 at a single frequency in response to the pressure change of the fluid in the tank unit 120.

[0149] The microcomputer unit 140A of the pump control system 100A according to the second embodiment performs control to obtain the characteristic K2 shown in FIG. 18 using the table shown in FIG. 21A, and performs control to obtain the characteristic K3 shown in FIG. 19 using the table shown in FIG. 21B. Each of the tables in FIGS. 21A and 21B has a table in which a plurality of different initial drive frequencies, the time to drive by each of these initial drive frequencies, and the target pressure corresponding to the drive time are associated with each other, and is stored in the storage unit 142. Thereby, the pump control system 100A can effectively increase the air in the tank unit 120 faster than single-frequency driving in response to the pressure change of the fluid in the tank unit 120 using the table according to the tank capacity.

[0150] <Switching pattern 2> FIG. 22 is a diagram showing a pattern in which the air in the tank is gently increased by the frequency control according to the first embodiment 2, and FIG. 23 is a table showing the case of controlling to obtain the characteristic K4 by switching the drive frequency shown in FIG. 22 according to the pressure value using the pump of the first embodiment. FIG. 24 is a table showing the case of controlling to obtain the characteristic K4 by switching the drive frequency shown in FIG. 22 according to the time using the pump of the second embodiment. In each figure, the initial drive frequencies are 300 Hz, 280 Hz, and 270 Hz, but this is an example, and the numerical values are not limited as long as they are a plurality of different frequencies.

[0151] The frequency control shown in FIG. 22 uses the frequency in the "frequency band (region) where it is difficult to output the flow rate", which is a frequency region higher than the second drive frequency H2, in the characteristics of the resonance type actuator shown in FIG. 14. In this way, the pump control system that controls the drive frequency of the current supplied to the coils 50a and 50b is used when it is desired to gently increase the air pressure, for example, when extending the pressure increase time. For example, the pump is used when it is necessary to gently send air during a blood vessel examination of an infant, tightening a belt on a subject, or the like.

[0152] <Third Embodiment> FIG. 25 is a diagram schematically showing a pump control system according to the third embodiment of the present invention. The pump control system shown in FIG. 25 is, for example, a blood pressure device 10D. The blood pressure device 10D includes a cuff 102 corresponding to the tank unit 120, a pipe unit 5 for sending air to the cuff, a pump drive unit 101, and a pressure measurement unit 13D.

[0153] The drive unit 101 includes a resonance pump 1D which is the pump 1 shown in FIG. 1, and a control unit 140 as a microcomputer unit.

[0154] The control unit 140 which is a microcomputer unit is connected to the resonance pump 1D and the pressure measurement unit 13D, and supplies a drive signal to the resonance pump 1D.

[0155] The resonance pump 1D is driven according to the drive signal from the microcomputer unit 140. Specifically, the pipe unit 5 is connected to the discharge part 86 of the resonance pump 1D, and in the resonance pump 1D, the vibrating body 30 vibrates, drives the pump part, and can preferably supply air to the cuff for blood pressure measurement etc. Due to the configuration of the pump control system, miniaturization is possible, more suitable pump pressure and flow rate can be ensured, stable driving can be achieved, and the pressure in the cuff can be increased to a desired pressure value in a short time for the cuff.

[0156] The embodiments of the present invention have been described above. Note that the above description is an illustration of a preferred embodiment of the present invention, and the scope of the present invention is not limited thereto. That is, the description of the configuration of the above device and the shape of each part is an example, and it is obvious that various changes and additions to these examples are possible within the scope of the present invention.

Industrial Applicability

[0157] The pump according to the present invention has the effects of being able to be miniaturized, ensuring more suitable pump pressure and flow rate, and being able to be stably driven. For example, the pump according to the present invention is useful as a wearable device where thinning and high output are desired. Therefore, the present invention has industrial applicability.

Claims

1. A vibration actuator that vibrates a vibrating body by electromagnetic drive by supplying current to a coil, A sealed chamber having a movable wall that is displaced by the vibration of the vibrating body, and when the movable wall is displaced, the internal volume is changed and fluid is sucked into or discharged from the inside, A discharge unit that fluidly communicates a tank that stores the fluid discharged from the sealed chamber and increases the pressure of the fluid with the sealed chamber, A pump control device for controlling a pump having: An acquisition unit that acquires pressure value information indicating a value of the pressure of the fluid in the tank or a value corresponding to the pressure, A control unit that controls a drive frequency of a current supplied to the coil based on the acquired pressure value information, and When the value of the pressure of the fluid in the tank reaches a switching pressure value, the control unit switches the drive frequency from a first drive frequency that maximizes the flow rate of the fluid from the pump to the tank to a second drive frequency that maximizes the pressure of the fluid in the tank, Pump control device.

2. The pump control device according to claim 1, wherein the control unit controls the drive frequency so that the current is supplied to the coil at a resonance frequency of the vibrating body that varies according to the pressure of the fluid in the tank.

3. The pump control device according to claim 1, wherein the second drive frequency is higher than the first drive frequency.

4. The pump control device according to claim 1, The pump, A pressure detection unit that measures the pressure of the fluid in the tank and obtains the pressure value information indicating the value of the pressure, Having, The acquisition unit acquires the pressure value information from the pressure detection unit, a pump control system.

5. The pump control device according to claim 1, The pump, A timer that measures a drive time of the vibrating body when increasing the pressure of the fluid in the tank and obtains the pressure value information indicating the drive time, Having, The acquisition unit acquires the pressure value information from the timer, a pump control system.

6. The pump control device has a storage unit that stores a table showing a relationship between a preset drive time of the vibrating body and the pressure of the fluid in the tank that increases with the drive time, The control unit controls the drive frequency using the table, the pump control system according to claim 5.

Images