JP2016200067A - Fluid control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluid control device that can cool a pump without a cooling device while being compact.SOLUTION: A fluid control device 100 comprises a piezoelectric pump 10, a valve 101, a cuff 109, a heat sink 123, and a control part 115. The valve 101 comprises a first valve case 191 provided with first vent holes 110 and 111, and a second valve case 192 provided with a second vent hole 112 and a third vent hole 113. A manchette rubber tube 109A of the cuff 109 is fitted to the second vent hole 112 of the valve 101, and the valve 101 is thereby connected to the cuff 109. The piezoelectric pump 10 comprises a pump case 80 provided with discharge holes 55 and 56. The first vent holes 110 and 111 of the valve 101 are connected to the discharge holes 55 and 56 of the piezoelectric pump 10. The heat sink 123 is fitted to a bottom surface of the pump case 80. The heat sink 123 comprises an opposed part 124 opposed to the third vent hole 113.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a fluid control device that controls the flow of fluid.

  Conventionally, various fluid control devices for controlling the flow of fluid have been devised. A plurality of electronic components are mounted on the fluid control device. Some of the plurality of electronic components continue to increase in temperature due to self-heating. If the temperature of the electronic component continues to rise, the performance of the electronic component may deteriorate or cause a failure.

  Thus, for example, Patent Document 1 discloses a heat sink and a cooling fan to be mounted on an electronic component. The cooling fan cools the heat sink by sending air toward the heat sink warmed by the heat generated by the electronic components. Thereby, in patent document 1, the temperature rise of an electronic component is suppressed.

JP 2007-42724 A

  The inventor of the present application has found that when a pump using, for example, a piezoelectric element as a drive source continues to be driven in the fluid control device, the temperature of the pump continues to rise due to self-heating and the discharge performance of the pump decreases. Therefore, a method of suppressing the temperature rise of the pump by mounting the heat sink of Patent Document 1 on the pump and cooling the heat sink with a cooling fan is conceivable.

  However, when the heat sink of Patent Document 1 is mounted on a pump and the heat sink is cooled by a cooling fan, a cooling fan dedicated to cooling is required. This means that a cooling fan must be prepared or a dedicated process for mounting the cooling fan has to be set up, which increases the manufacturing cost of the fluid control device.

  Therefore, in order to suppress the temperature rise of the pump, a method of mounting only the heat sink without mounting a cooling device such as a cooling fan is conceivable. However, to obtain a sufficient cooling effect, the size of the heat sink is increased. There is a need. Therefore, this method has a problem that the fluid control device is enlarged.

  The objective of this invention is providing the fluid control apparatus which can cool a pump, without using a cooling device, though it is small.

  The fluid control device of the present invention includes a pump, a valve, a container, and a heat sink. The pump has a pump housing provided with a discharge hole. The valve has a valve housing provided with a first vent hole, a second vent hole, and a third vent hole that are connected to the discharge hole. The container is connected to the second ventilation hole and stores gas flowing out from the second ventilation hole via the first ventilation hole. The heat sink has a facing portion facing the third ventilation hole, and was mounted on the pump housing.

  In this configuration, while the pump is driven, the gas discharged from the discharge hole of the pump flows into the valve housing from the first vent hole. And the gas which flows out out of the 2nd vent hole of a valve | bulb is stored in a container. Further, while the pump is being driven, the temperature of the pump continues to rise due to self-heating.

  In this configuration, since the heat sink having excellent thermal conductivity is attached to the pump casing, the heat generated by the pump is conducted from the pump casing to the heat sink and dissipated. Furthermore, when the second vent hole and the third vent hole are connected, the compressed gas stored in the container is discharged from the third vent hole of the valve toward the opposite portion of the heat sink.

  Therefore, the fluid control device with this configuration can cool the heat sink without suppressing the heat sink without providing a large-sized heat sink or a dedicated cooling device, and can suppress an increase in pump temperature.

  Therefore, the fluid control device having this configuration is small, but can cool the pump without using a cooling device.

In the present invention, the valve has a valve body that constitutes the first valve chamber and the second valve chamber together with the valve housing,
Based on the pressure in the first valve chamber and the pressure in the second valve chamber, the valve body is in a state where the second vent hole and the third vent hole are not connected, and the second vent hole and the third vent hole are connected. It is preferable to switch between states.

  In this configuration, when the second ventilation hole and the third ventilation hole are not connected, the gas discharged from the discharge hole of the pump flows out from the second ventilation hole via the first ventilation hole of the valve and enters the container. Stored. When the second vent hole and the third vent hole are connected, the compressed gas stored in the container is discharged from the third vent hole of the valve toward the opposite portion of the heat sink.

  In the present invention, the facing portion is preferably bent toward the valve housing.

  In this configuration, the area of the heat sink to which the gas discharged from the third vent hole of the valve hits increases. Therefore, the fluid control device having this configuration can improve the cooling effect of the pump.

  Moreover, in this invention, it is preferable that the surface which opposes the 3rd ventilation hole in an opposing part is formed in the uneven | corrugated shape.

  In this configuration, the area of the heat sink to which the gas discharged from the third vent hole of the valve hits increases. Therefore, the fluid control device having this configuration can improve the cooling effect of the pump.

  In the present invention, the facing portion is preferably formed in a comb shape.

  In this configuration, the area of the heat sink to which the gas discharged from the third vent hole of the valve hits increases. Therefore, the fluid control device having this configuration can improve the cooling effect of the pump.

  In the present invention, the pump preferably includes a diaphragm and a piezoelectric element that flexibly vibrates the diaphragm.

  When a pump using a piezoelectric element as a drive source continues to be driven, the temperature of the pump continues to rise due to self-heating, and the discharge performance of the pump decreases. Therefore, the present invention is suitable in this configuration.

  Moreover, it is preferable that the fluid control apparatus of this invention is provided with the control part which measures a blood pressure based on the pressure of the gas stored in a container.

  In this configuration, the container is a cuff, for example. For example, the control unit turns on the pump when starting measurement of blood pressure. Thereby, gas is discharged from the discharge hole of the pump and stored in the container. And a control part turns off a pump, when complete | finishing the measurement of a blood pressure. Thereby, the compressed gas stored in the container is discharged from the third vent hole of the valve toward the opposing portion of the heat sink.

  Therefore, when the blood pressure is measured a plurality of times, the fluid control device having this configuration can cool the heat sink every time the measurement of the blood pressure is finished, and can suppress an increase in the temperature of the pump.

  According to the present invention, the pump can be cooled without using a cooling device while being small.

It is sectional drawing of the principal part of the fluid control apparatus 100 which concerns on 1st Embodiment of this invention. FIG. 2 is an external perspective view of a piezoelectric pump 10, a valve 101, and a heat sink 123 shown in FIG. It is a disassembled perspective view of the piezoelectric pump 10 shown in FIG. It is a figure which shows the relationship between the temperature of the piezoelectric pump 10 shown in FIG. 1, and a maximum discharge pressure. It is a disassembled perspective view of the valve | bulb 101 shown in FIG. It is a disassembled perspective view of the valve | bulb 101 shown in FIG. It is explanatory drawing which shows the flow of the air of the fluid control apparatus 100 while the piezoelectric pump 10 shown in FIG. 1 drives. It is explanatory drawing which shows the flow of the air of the fluid control apparatus 100 immediately after the piezoelectric pump 10 shown in FIG. 1 stops a drive. It is a figure which shows the temperature change of the piezoelectric pump 10 with which the heat sink 123 was mounted | worn, and the temperature change of the piezoelectric pump 10 with which the heat sink 123 was not mounted | worn. It is sectional drawing of the principal part of the fluid control apparatus 200 which concerns on 2nd Embodiment of this invention. FIG. 11 is an external perspective view of the piezoelectric pump 10, the valve 101, and the heat sink 223 shown in FIG. It is the external appearance perspective view which expanded the principal part of the heat sink 223 shown in FIG. It is sectional drawing of the principal part of the fluid control apparatus 300 which concerns on 3rd Embodiment of this invention. It is the external appearance perspective view which expanded the principal part of the heat sink 323 shown in FIG. It is an external appearance perspective view of the piezoelectric pump 10, the valve | bulb 101, and the heat sink 423 with which the fluid control apparatus which concerns on 4th Embodiment of this invention is equipped.

  Hereinafter, the fluid control apparatus 100 according to the first embodiment of the present invention will be described.

  FIG. 1 is a cross-sectional view of a main part of a fluid control apparatus 100 according to the first embodiment of the present invention. FIG. 2 is an external perspective view of the piezoelectric pump 10, the valve 101, and the heat sink 123 shown in FIG. FIG. 2 shows the heat sink 123 in a transparent manner for convenience of explanation.

  The fluid control apparatus 100 includes a piezoelectric pump 10, a valve 101, a cuff 109, a heat sink 123, and a control unit 115. The fluid control device 100 is a device that measures the blood pressure of a subject.

  The valve 101 includes a first valve housing 191 provided with first ventilation holes 110 and 111, and a second valve housing 192 provided with a second ventilation hole 112 and a third ventilation hole 113. The valve 101 constitutes a check valve 160 and an exhaust valve 170. The armband rubber tube 109 </ b> A of the cuff 109 is attached to the second ventilation hole 112 of the valve 101, so that the valve 101 is connected to the cuff 109. The third vent hole 113 is open to the atmosphere.

  The piezoelectric pump 10 has a pump housing 80 provided with discharge holes 55 and 56. The upper surface of the pump housing 80 is joined to the bottom surface of the first valve housing 191 of the valve 101. Thereby, the first vent holes 110 and 111 of the valve 101 are connected to the discharge holes 55 and 56 of the piezoelectric pump 10.

  The heat sink 123 is attached to the bottom surface of the pump housing 80. As shown in FIGS. 1 and 2, the heat sink 123 extends from the bottom surface of the pump housing 80 to the side surface of the pump housing 80, the side surface of the first valve housing 191, the side surface of the second valve housing 192, and the second valve. It extends along the upper surface of the housing 192. The heat sink 123 has a facing portion 124 that faces the third ventilation hole 113. The facing portion 124 is a portion of the heat sink 123 that extends along the upper surface of the second valve housing 192. The material of the heat sink 123 is, for example, aluminum, iron, copper, or the like.

  The control unit 115 is configured by a microcomputer, for example, and controls the operation of each unit of the fluid control device 100. The control unit 115 is connected to the piezoelectric pump 10 and transmits a control signal to the piezoelectric pump 10. The control unit 115 generates an AC drive voltage from a commercial AC power source and applies it to the piezoelectric pump 10 to drive the piezoelectric pump 10. Then, the control unit 115 measures the blood pressure based on the pressure of the air stored in the cuff 109. The pressure value of the air stored in the cuff 109 is detected by a pressure sensor (not shown) and input to the control unit 115.

  The cuff 109 corresponds to an example of the “container” of the present invention. The first valve housing 191 and the second valve housing 192 constitute an example of the “valve housing” of the present invention.

  Here, the structure of the piezoelectric pump 10 and the valve 101 will be described in detail. First, the structure of the piezoelectric pump 10 will be described in detail with reference to FIGS.

  FIG. 3 is an exploded perspective view of the piezoelectric pump 10 shown in FIG.

  The piezoelectric pump 10 includes a substrate 91, a flexible plate 51, a spacer 53A, a reinforcing plate 43, a vibration plate unit 60, a piezoelectric element 42, a spacer 53B, an electrode conduction plate 70, a spacer 53C, and a lid plate 54 in order. It has a laminated structure.

  The substrate 91, the flexible plate 51, the spacer 53A, a part of the diaphragm unit 60, the spacer 53B, the electrode conduction plate 70, the spacer 53C, and the lid plate 54 constitute a pump housing 80. The internal space of the pump housing 80 corresponds to the pump chamber 45. The material of the pump housing 80 is, for example, metal.

  The diaphragm unit 60 includes a diaphragm 41, a frame plate 61, a connecting portion 62, and an external terminal 63. The diaphragm unit 60 is formed by punching a metal plate.

  A frame plate 61 is provided around the vibration plate 41. The frame plate 61 is provided with an external terminal 63 for electrical connection. The diaphragm 41 is connected to the frame plate 61 by a connecting portion 62. The connecting part 62 is formed in a thin ring shape, for example. The connecting portion 62 has an elastic structure having a small spring constant elasticity.

  Therefore, the diaphragm 41 is elastically supported at two points with respect to the frame plate 61 by the two connecting portions 62. Therefore, the bending vibration of the diaphragm 41 is hardly disturbed. That is, the peripheral part of the piezoelectric actuator 40 (of course, the central part) is not substantially restrained.

  In addition, in the example shown in FIG. 3, although the connection part 62 is provided in two places, you may provide in three or more places. The connecting portion 62 does not disturb the vibration of the piezoelectric actuator 40, but has some influence on the vibration of the piezoelectric actuator 40. Therefore, for example, by providing the connecting portions 62 at three locations, more natural support is possible, and cracking of the piezoelectric element 42 can also be prevented.

  A piezoelectric element 42 is provided on the upper surface of the disc-shaped diaphragm 41. A reinforcing plate 43 is provided on the lower surface of the vibration plate 41. The diaphragm 41, the piezoelectric element 42, and the reinforcing plate 43 constitute a disk-shaped piezoelectric actuator 40. The piezoelectric element 42 is made of, for example, lead zirconate titanate ceramic.

  Here, the vibration plate 41 may be formed of a metal plate having a larger linear expansion coefficient than the piezoelectric element 42 and the reinforcing plate 43, and may be heat-cured during bonding. Accordingly, an appropriate compressive stress can be left in the piezoelectric element 42 without warping the entire piezoelectric actuator 40, and the piezoelectric element 42 can be prevented from cracking.

  For example, the diaphragm 41 may be made of a material having a large linear expansion coefficient such as phosphor bronze (C5210) or stainless steel SUS301, and the reinforcing plate 43 may be made of 42 nickel, 36 nickel or stainless steel SUS430.

  Note that the diaphragm 41, the piezoelectric element 42, and the reinforcing plate 43 may be arranged in the order of the piezoelectric element 42, the reinforcing plate 43, and the diaphragm 41 from the top. Also in this case, the linear expansion coefficient is adjusted by setting the materials constituting the reinforcing plate 43 and the diaphragm 41 so that an appropriate compressive stress remains in the piezoelectric element 42.

  A spacer 53 </ b> B is provided on the upper surface of the frame plate 61. The spacer 53B is made of resin. The thickness of the spacer 53B is the same as or slightly thicker than that of the piezoelectric element. The frame plate 61 electrically insulates the electrode conduction plate 70 and the diaphragm unit 60 from each other.

  An electrode conduction plate 70 is provided on the upper surface of the spacer 53B. The electrode conduction plate 70 is made of metal. The electrode conduction plate 70 includes a frame portion 71 that is opened in a substantially circular shape, an internal terminal 73 that projects into the opening, and an external terminal 72 that projects outward.

  The tip of the internal terminal 73 is joined to the surface of the piezoelectric element 42 with solder. By setting the position to be joined by solder to a position corresponding to the bending vibration node of the piezoelectric actuator 40, the vibration of the internal terminal 73 is suppressed.

  A spacer 53 </ b> C is provided on the upper surface of the electrode conduction plate 70. The spacer 53C is made of resin. The spacer 53C has the same thickness as the piezoelectric element 42. The spacer 53 </ b> C is a spacer for preventing the solder portion of the internal terminal 73 from contacting the lid plate 54 when the piezoelectric actuator 40 is vibrating. In addition, the surface of the piezoelectric element 42 is prevented from excessively approaching the cover plate 54 and the vibration amplitude is prevented from being reduced by air resistance. Therefore, the thickness of the spacer 53 </ b> C may be the same as that of the piezoelectric element 42.

  A cover plate 54 is provided on the upper surface of the spacer 53C. The lid plate 54 is provided with discharge holes 55 and 56. The lid plate 54 covers the upper part of the piezoelectric actuator 40.

  On the other hand, a spacer 53 </ b> A is provided on the lower surface of the diaphragm unit 60. That is, the spacer 53 </ b> A is inserted between the upper surface of the flexible plate 51 and the lower surface of the diaphragm unit 60. The spacer 53 </ b> A has a thickness obtained by adding about several tens of μm to the thickness of the reinforcing plate 43. The spacer 53A is a spacer for preventing the piezoelectric actuator 40 from coming into contact with the flexible plate 51 when the piezoelectric actuator 40 is vibrating.

  A flexible plate 51 is provided on the lower surface of the spacer 53A. A suction hole 52 is provided at the center of the flexible plate 51.

  A substrate 91 is provided on the lower surface of the flexible plate 51. A cylindrical opening 92 is formed at the center of the substrate 91. The flexible plate 51 includes a fixed portion 57 fixed to the substrate 91 and a movable portion 58 that is located on the center side of the fixed portion 57 and faces the opening 92.

  The movable portion 58 can vibrate at substantially the same frequency as that of the piezoelectric actuator 40 due to air pressure fluctuation accompanying vibration of the piezoelectric actuator 40. The natural frequency of the movable part 58 is designed to be the same as or slightly lower than the drive frequency of the piezoelectric actuator 40.

  If the vibration is designed so that the vibration phase of the flexible plate 51 is delayed (for example, 180 ° delayed) from the vibration phase of the piezoelectric actuator 40, the thickness variation of the gap between the flexible plate 51 and the piezoelectric actuator 40 is substantially reduced. Increase.

  Accordingly, when an AC driving voltage is applied to the external terminals 63 and 72 by the control unit 115, the piezoelectric actuator 40 bends and vibrates in a concentric manner. Further, the movable portion 58 of the flexible plate 51 also vibrates with the vibration of the piezoelectric actuator 40. As a result, the piezoelectric pump 10 sucks air into the pump chamber 45 through the opening 92 and the suction hole 52. Further, the piezoelectric pump 10 discharges air in the pump chamber 45 from the discharge holes 55 and 56.

  At this time, in the piezoelectric pump 10, the periphery of the piezoelectric actuator 40 is not substantially fixed. Therefore, according to the piezoelectric pump 10, there is little loss due to vibration of the piezoelectric actuator 40, and a high discharge pressure and a large discharge flow rate can be obtained while being small and low-profile.

  Next, the relationship between the temperature of the piezoelectric pump 10 and the maximum discharge pressure will be described.

  FIG. 4 is a diagram showing the relationship between the temperature of the piezoelectric pump 10 shown in FIG. 1 and the maximum discharge pressure. FIG. 4 shows the results of measuring the surface temperature of the pump housing 80 and the maximum discharge pressure of the piezoelectric pump 10 by driving the piezoelectric pump 10 for a long time.

  When the piezoelectric pump 10 using the piezoelectric element 42 as a drive source continues to be driven, the temperature of the piezoelectric pump 10 continues to rise due to self-heating. In the experiment, as shown in FIG. 4, it has been clarified that the discharge performance of the piezoelectric pump 10 decreases as the temperature of the piezoelectric pump 10 continues to rise. In particular, it has been clarified that when the temperature of the piezoelectric pump 10 exceeds 55 ° C., the discharge performance of the piezoelectric pump 10 rapidly decreases.

  The heat source for self-heating is the piezoelectric actuator 40, but the material of the pump housing 80 is made of a highly conductive metal. Therefore, the heat of the piezoelectric actuator 40 is immediately conducted to the pump housing 80 via the connecting portion 62. Therefore, in FIG. 4, the surface temperature of the pump housing 80 is measured.

  Next, the structure of the valve 101 will be described in detail with reference to FIGS.

  5 and 6 are exploded perspective views of the valve 101 shown in FIG. FIG. 5 is an exploded perspective view of the valve 101 as viewed from the upper surface side where the cuff 109 is connected, and FIG. 6 is an exploded perspective view of the valve 101 as viewed from the bottom surface side where the piezoelectric pump 10 is joined.

  Here, FIG. 5 shows the Z-axis direction, the Y-axis direction, and the X-axis direction. A Z-axis direction indicates a stacking direction of members constituting the valve 101. The X-axis direction indicates the arrangement direction of the check valve 160, the communication path 135, and the exhaust valve 170. The Y-axis direction indicates a direction perpendicular to the Z-axis direction and the X-axis direction.

  As shown in FIGS. 1, 5, and 6, the valve 101 includes a first valve casing 191, a first sealing material 151 made of a rectangular thin film, a diaphragm 120 made of a rectangular thin film, and a rectangular shape. The second sealing material 152 made of the above thin film and the second valve housing 192 are provided, and these are laminated in order.

  The diaphragm 120 constitutes an example of the “valve element” of the present invention.

  As shown in FIGS. 1, 5, and 6, the second valve housing 192 includes a second vent hole 112 communicating with the cuff 109, a third vent hole 113 communicating with the outside of the fluid control device 100, and a third It has a valve seat 139 protruding from the periphery of the vent hole 113 to the diaphragm 120 side, and six openings 182. The second valve housing 192 is made of resin, for example. The valve seat 139 has a cylindrical shape having a third vent hole 113 at the center.

  As shown in FIGS. 1, 5, and 6, the first valve housing 191 includes a first vent hole 110 that communicates with the discharge hole 56 of the piezoelectric pump 10 and a first vent that communicates with the discharge hole 55 of the piezoelectric pump 10. It has a vent 111, a cylindrical valve seat 138 that protrudes toward the diaphragm 120, and six protrusions 180 that face the six openings 182. The first valve housing 191 is made of resin, for example. The six projecting portions 180 of the first valve housing 191 are provided on the peripheral side of the second valve chamber 133 and the second valve chamber 134 which will be described later in plan view from the X-axis direction.

  As shown in FIGS. 1, 5, and 6, the diaphragm 120 is provided with a circular hole 121 at the center of a region facing the valve seat 138. The diameter of the hole 121 is smaller than the diameter of the surface of the valve seat 138 that contacts the diaphragm 120. The outer periphery of the diaphragm 120 is smaller than the outer periphery of each of the first valve housing 191 and the second valve housing 192. The diaphragm 120 is made of rubber such as EPDM (ethylene propylene diene rubber) or silicone.

  The diaphragm 120 is sandwiched between the first valve casing 191 and the second valve casing 192 via the second seal member 152 and the first seal member 151 by fitting the six projecting portions 180 into the six openings 182. Yes.

  Thereby, a part of the diaphragm 120 comes into contact with the valve seat 139 and the periphery of the hole 121 in the diaphragm 120 comes into contact with the valve seat 138. The valve seat 138 is provided in the first valve housing 191 so as to pressurize the periphery of the hole 121 in the diaphragm 120.

  The diaphragm 120 divides the second valve housing 192 and the first valve housing 191. The diaphragm 120 has a check valve having a ring-shaped first valve chamber 131 communicating with the first ventilation hole 111 and a columnar second valve chamber 133 communicating with the second ventilation hole 112 via the communication passage 135. 160 is configured together with the second valve housing 192 and the first valve housing 191.

  The diaphragm 120 has an exhaust having a columnar first valve chamber 132 communicating with the first vent hole 110 and a ring-shaped second valve chamber 134 communicating with the second valve chamber 133 via the communication path 135. The valve 170 is configured together with the second valve housing 192 and the first valve housing 191.

  The diameters of the first valve chamber 131, the first valve chamber 132, the second valve chamber 133, and the second valve chamber 134 are, for example, 7.0 mm. The diameter of the surface of the valve seat 138 that contacts the diaphragm 120 is, for example, 1.5 mm.

  The second sealing material 152 is provided with second through holes 156 </ b> A to 156 </ b> C in regions facing the second valve chamber 133, the communication path 135, and the second valve chamber 134. The second through hole 156A has, for example, a circular shape whose central axis is substantially the same as that of the second valve chamber 133. The second through hole 156B has, for example, a circular shape whose central axis is substantially the same as that of the second valve chamber 134.

  The diameters of the second through holes 156A and 156B are, for example, 6.6 mm. That is, the outer periphery of the second sealing material 152 is smaller than the outer periphery of each of the first valve housing 191 and the second valve housing 192. The second sealing material 152 is made of, for example, a double-sided tape or an adhesive.

  Next, first through holes 155 </ b> A and 155 </ b> B are provided in the first sealing material 151 in regions facing the first valve chamber 131 and the first valve chamber 132. The first through hole 155A has, for example, a circular shape whose central axis is substantially the same as that of the first valve chamber 131. The first through hole 155B has, for example, a circular shape whose central axis is substantially the same as that of the first valve chamber 132.

  The diameters of the first through holes 155A and 155B are, for example, 6.6 mm. That is, the outer periphery of the first sealing material 151 is smaller than the outer periphery of each of the first valve housing 191 and the second valve housing 192. The first sealing material 151 is made of, for example, a double-sided tape or an adhesive.

  The diameter of the first through hole 155A is larger than the diameter of the valve seat 138 and smaller than the diameter of the first valve chamber 131. That is, the outer periphery of the first through hole 155A is larger than the outer periphery of the valve seat 138 and smaller than the outer periphery of the first valve chamber 131. Similarly, the diameter of the first through hole 155 </ b> B is smaller than the diameter of the first valve chamber 132. That is, the outer periphery of the first through hole 155B is smaller than the outer periphery of the first valve chamber 132.

  As described above, in the valve 101, a part of the second sealing material 152 is located in the second valve chamber 133 and the second valve chamber 134. Similarly, a part of the first sealing material 151 is located in the first valve chamber 131 and the first valve chamber 132.

  Next, the check valve 160 and the exhaust valve 170 which the valve 101 constitutes will be described.

  First, the check valve 160 includes a part of the first valve housing 191 provided with the first ventilation hole 111, a part of the second valve housing 192 provided with the second ventilation hole 112, and the hole 121 in the diaphragm 120. , And a valve seat 138 that contacts the periphery and covers the hole 121. The check valve 160 allows the flow of fluid from the first valve chamber 131 side to the second valve chamber 133 side, and blocks the flow of fluid from the second valve chamber 133 side to the first valve chamber 131 side.

  Therefore, in the check valve 160, the diaphragm 120 contacts or separates from the valve seat 138 based on the pressure in the first valve chamber 131 and the pressure in the second valve chamber 133.

  Next, the exhaust valve 170 includes a part of the first valve casing 191 including the first vent hole 110, a part of the second valve casing 192 including the second vent hole 112 and the third vent hole 113, A part of the diaphragm 120 and a valve seat 139 that protrudes from the periphery of the third vent hole 113 toward the diaphragm 120 and is covered with the diaphragm 120 are covered.

  Therefore, in the exhaust valve 170, the diaphragm 120 comes into contact with or separates from the valve seat 139 based on the pressure in the first valve chamber 132 and the pressure in the second valve chamber 134.

  In this valve 101, as shown in FIGS. 5 and 6, the outer shapes of the valve chambers 131, 132, 133, and 134 are circular, so that the diaphragm 120 (particularly around the hole 121) is formed. The tension is applied evenly.

  For this reason, the hole 121 of the diaphragm 120 abuts against the valve seat 138 in a tilted state, and the hole 121 of the diaphragm 120 is prevented from being displaced in the horizontal direction with respect to the valve seat 138. Therefore, according to this valve 101, each valve can be opened and closed more reliably.

  Next, the operation of the fluid control device 100 during blood pressure measurement will be described.

  FIG. 7 is an explanatory diagram showing the air flow of the fluid control device 100 while the piezoelectric pump 10 shown in FIG. 1 is being driven.

  The control unit 115 turns on the piezoelectric pump 10 when starting measurement of blood pressure. When the piezoelectric pump 10 is driven, air first flows into the pump chamber 45 in the piezoelectric pump 10 from the opening 92 and the suction hole 52. Next, air is discharged from the discharge holes 55 and 56 and flows into both the first valve chamber 132 and the first valve chamber 131 of the valve 101.

  Thereby, in the exhaust valve 170, the pressure in the first valve chamber 132 becomes higher than the pressure in the second valve chamber 134. For this reason, as shown in FIG. 7, the diaphragm 120 seals the third ventilation hole 113 and blocks the connection between the second ventilation hole 112 and the third ventilation hole 113.

  In the check valve 160, the pressure in the first valve chamber 131 is higher than the pressure in the second valve chamber 133. For this reason, the periphery of the hole 121 in the diaphragm 120 is separated from the valve seat 138, and the first ventilation hole 111 and the second ventilation hole 112 are connected via the hole 121.

  As a result, air is sent from the piezoelectric pump 10 to the cuff 109 via the first ventilation hole 111, the hole 121, and the second ventilation hole 112 of the valve 101 (see FIG. 7). Pressure (air pressure) increases. Further, while the piezoelectric pump 10 is being driven, the temperature of the piezoelectric pump 10 continues to rise due to self-heating (see, for example, FIG. 4). However, since the heat sink 123 having excellent thermal conductivity is mounted on the piezoelectric pump 10 housing, the heat generated in the piezoelectric pump 10 is conducted from the piezoelectric pump 10 housing to the heat sink 123 and is gradually dissipated.

  The diaphragm 120 is fixed to the second valve housing 192 and the first valve housing 191 so that the periphery of the hole portion 121 of the diaphragm 120 is in contact with the valve seat 138. The valve seat 138 pressurizes the periphery of the hole 121 in the diaphragm 120.

  As a result, the air flowing out from the hole 121 via the first vent hole 111 of the valve 101 becomes a pressure slightly lower than the discharge pressure of the piezoelectric pump 10, and the second valve chamber 133 and the second from the hole 121. It flows into the valve chamber 134. On the other hand, the discharge pressure of the piezoelectric pump 10 is applied to the first valve chamber 132.

  As a result, in the valve 101, the pressure in the first valve chamber 132 is slightly higher than the pressure in the second valve chamber 134, and the state where the diaphragm 120 seals the third vent hole 113 and opens the hole 121 is maintained.

  FIG. 8 is an explanatory diagram showing the air flow of the fluid control device 100 immediately after the piezoelectric pump 10 shown in FIG. 1 stops driving.

  When the blood pressure measurement ends, the control unit 115 turns off the piezoelectric pump 10. Here, when the driving of the piezoelectric pump 10 stops, the air in the pump chamber 45, the first valve chamber 131, and the first valve chamber 132 flows from the suction hole 52 and the opening 92 of the piezoelectric pump 10 to the outside of the fluid control device 100. Immediately exhausted. Further, the pressure of the cuff 109 is applied to the second valve chamber 133 and the second valve chamber 134 from the second vent hole 112.

  As a result, in the check valve 160, the pressure in the first valve chamber 131 is lower than the pressure in the second valve chamber 133. The diaphragm 120 contacts the valve seat 138 and seals the hole 121.

  In the exhaust valve 170, the pressure in the first valve chamber 132 is lower than the pressure in the second valve chamber 134. The diaphragm 120 is separated from the valve seat 139 and opens the third vent hole 113. That is, in the valve 101, the second ventilation hole 112 and the third ventilation hole 113 are connected via the communication path 135 and the second valve chamber 134. Thereby, the air in the cuff 109 is rapidly discharged from the third vent hole 113 toward the facing portion 124 of the heat sink 123 via the second vent hole 112, the communication path 135, and the second valve chamber 134. The volume of air stored in the cuff 109 is extremely larger than the volume of the piezoelectric pump 10, and a large amount of air is discharged from the third vent 113 toward the facing portion 124 of the heat sink 123.

  Therefore, the fluid control device 100 can cool the heat sink 123 without including a large heat sink 123 or a dedicated cooling device, and can suppress an increase in temperature of the piezoelectric pump 10.

  Therefore, the fluid control device 100 can cool the piezoelectric pump 10 without using a cooling device, although it is small.

  Thereafter, the control unit 115 turns on the piezoelectric pump 10 when the blood pressure measurement is started, and turns off the piezoelectric pump 10 when the blood pressure measurement is finished. Thereby, when measuring the blood pressure a plurality of times, the fluid control device 100 can cool the heat sink 123 every time the measurement of the blood pressure is finished.

  In the valve 101, as described above, a part of the first sealing material 151 is located in the first valve chamber 131 and the first valve chamber 132, and the second valve chamber 133 and the second valve chamber 134 are in the second state. A part of the sealing material 152 is located.

  Therefore, the second sealing material 152 and the first sealing material 151 are used to bond the first valve housing 191, the second valve housing 192, and the diaphragm 120 and to capture foreign substances present in the valve chambers 131, 132, 133, and 134. And can be done.

  Therefore, according to the valve 101, for example, even if foreign matter is mixed in the valve 101, malfunction due to the foreign matter can be suppressed. Particularly in the exhaust valve 170, it is possible to prevent the third vent hole 113 of the valve seat 139 from being blocked by a foreign object.

  Hereinafter, the temperature change of the piezoelectric pump 10 in the fluid control apparatus 100 according to the first embodiment of the present invention is compared with the temperature change of the piezoelectric pump 10 in the fluid control apparatus according to the comparative example of the first embodiment of the present invention. . The difference between the fluid control device of the comparative example and the fluid control device 100 of the first embodiment is that the heat sink 123 is not provided. Since the other points are the same, the description is omitted.

  FIG. 9 is a diagram illustrating a temperature change of the piezoelectric pump 10 to which the heat sink 123 is attached and a temperature change of the piezoelectric pump 10 to which the heat sink 123 is not attached. FIG. 9 shows the result of measuring the temperature change of the piezoelectric pump 10 when the blood pressure is measured three times using the cuff 109 having a volume of air that can be stored is 250 cc.

  9 indicates the temperature change of the piezoelectric pump 10 to which the heat sink 123 is attached, and the dotted line in FIG. 9 indicates the temperature change of the piezoelectric pump 10 to which the heat sink 123 is not attached.

  From the experiment, as shown in FIG. 9, while both the piezoelectric pumps 10 are driven, the temperature of the piezoelectric pump 10 continues to rise due to self-heating, and from when the drive is stopped until the drive is restarted, It became clear that the temperature of the piezoelectric pump 10 decreased.

  However, as shown in FIG. 9, in the piezoelectric pump 10 not equipped with the heat sink 123, the temperature of the piezoelectric pump 10 gradually decreases from when the driving is stopped until the driving is restarted. Thus, it has been clarified that in the piezoelectric pump 10 to which the heat sink 123 is attached, the temperature of the piezoelectric pump 10 rapidly decreases from when the driving is stopped until the driving is restarted.

  The reason for the above results is that, as shown in FIG. 8, immediately after the piezoelectric pump 10 stops driving, the air in the cuff 109 passes through the second vent hole 112 and passes through the third vent hole 113 to the heat sink 123. This is considered to be because the heat sink 123 is rapidly discharged toward the facing portion 124 of the heat sink 123 to cool the heat sink 123.

  Therefore, the piezoelectric pump 10 with the heat sink 123 attached can suppress the temperature rise of the piezoelectric pump 10 as compared with the piezoelectric pump 10 without the heat sink 123 attached.

  Therefore, the fluid control device 100 can effectively cool the piezoelectric pump 10 while being small.

  Hereinafter, a fluid control device according to a second embodiment of the present invention will be described.

  FIG. 10 is a cross-sectional view of a main part of a fluid control device 200 according to the second embodiment of the present invention. FIG. 11 is an external perspective view of the piezoelectric pump 10, the valve 101, and the heat sink 223 shown in FIG. FIG. 12 is an external perspective view in which a main part of the heat sink 223 shown in FIG. 11 is enlarged.

  The difference between the fluid control device 200 of the second embodiment and the fluid control device 100 of the first embodiment is a heat sink 223. The heat sink 223 is different from the heat sink 123 of the first embodiment in that the front end of the facing portion 224 is bent toward the second valve housing 192 side. Since the other points are the same, the description is omitted.

  Compared to the heat sink 123 shown in FIG. 1, the heat sink 223 has an increased area where the air discharged from the third vent hole 113 of the valve 101 hits. Therefore, the fluid control apparatus 200 of this embodiment can improve the cooling effect of the piezoelectric pump 10.

  Hereinafter, a fluid control device according to a third embodiment of the present invention will be described.

  FIG. 13 is a cross-sectional view of a main part of a fluid control device 300 according to the third embodiment of the present invention. FIG. 14 is an external perspective view in which a main part of the heat sink 323 shown in FIG. 13 is enlarged.

  The difference between the fluid control device 300 of the third embodiment and the fluid control device 200 of the second embodiment is a heat sink 323. The difference between the heat sink 323 and the heat sink 223 of the second embodiment is that the surface of the facing portion 324 that faces the third ventilation hole 113 is formed in an uneven shape. Since the other points are the same, the description is omitted.

  Compared to the heat sink 223 shown in FIG. 11, the heat sink 323 has an increased area where the air discharged from the third vent 113 of the valve 101 hits. Therefore, the fluid control device of this embodiment can further improve the cooling effect of the piezoelectric pump 10.

  Similarly, in the heat sink 123 shown in FIG. 1, the surface of the facing portion 124 that faces the third ventilation hole 113 may be formed in an uneven shape.

  Hereinafter, a fluid control device according to a fourth embodiment of the present invention will be described.

  FIG. 15 is an external perspective view of the piezoelectric pump 10, the valve 101, and the heat sink 423 provided in the fluid control apparatus according to the fourth embodiment of the present invention.

  The difference between the fluid control device of the fourth embodiment and the fluid control device 200 of the second embodiment is a heat sink 423. The heat sink 423 is different from the heat sink 223 of the second embodiment in that the facing portion 424 is formed in a comb shape. Since the other points are the same, the description is omitted.

  Compared to the heat sink 223 shown in FIG. 11, the heat sink 423 has an increased area where the air discharged from the third vent hole 113 of the valve 101 hits. Therefore, the fluid control device of this embodiment can further improve the cooling effect of the piezoelectric pump 10.

  Similarly, in the heat sink 423 shown in FIG. 15, the surface of the facing portion 424 facing the third ventilation hole 113 may be formed in an uneven shape.

<< Other Embodiments >>
In the above-described embodiment, air is used as the fluid, but the present invention is not limited to this. In implementation, the fluid is applicable even if it is a gas other than air.

  In the above-described embodiment, the heat sinks 123, 223, 323, and 423 are mounted on the bottom surface of the pump housing 80, but the present invention is not limited to this. In practice, the heat sink may be mounted anywhere in the pump housing. For example, the heat sink may be attached to the side surface of the pump housing 80.

  In addition, the pump in the above-described embodiment includes the unimorph actuator 40 that bends and vibrates, but may include a bimorph actuator that vibrates and vibrates by attaching piezoelectric elements to both surfaces of the diaphragm.

  Further, the pump in the above-described embodiment includes the actuator 40 that bends and vibrates by expansion and contraction of the piezoelectric element 42, but is not limited thereto. For example, an actuator that bends and vibrates by electromagnetic drive may be provided.

  In the above-described embodiment, the piezoelectric element is composed of lead zirconate titanate ceramics, but is not limited thereto. For example, it may be made of a non-lead piezoelectric ceramic material such as potassium sodium niobate and alkali niobate ceramics.

  Finally, the description of the above-described embodiment is to be considered in all respects as illustrative and not restrictive. The scope of the present invention is shown not by the above embodiments but by the claims. Furthermore, the scope of the present invention is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

DESCRIPTION OF SYMBOLS 10 ... Piezoelectric pump 40 ... Piezoelectric actuator 41 ... Vibration plate 42 ... Piezoelectric element 43 ... Reinforcement plate 45 ... Pump chamber 51 ... Flexible plate 52 ... Suction hole 53A, 53B, 53C ... Spacer 54 ... Cover plate 55, 56 ... Discharge hole 57 ... fixed part 58 ... movable part 60 ... diaphragm unit 61 ... frame plate 62 ... coupling part 63, 72 ... external terminal 70 ... electrode conduction plate 71 ... frame part 73 ... internal terminal 80 ... pump housing 91 ... substrate 92 ... Opening portions 100, 200, 300 ... Fluid control device 101 ... Valve 109 ... Cuff 109A ... armband rubber tubes 110, 111 ... first vent hole 112 ... second vent hole 113 ... third vent hole 115 ... control unit 120 ... Diaphragm 121 ... holes 123, 223, 323, 423 ... heat sinks 124, 224, 324, 424 ... opposite parts 131, 132 ... first valve chambers 133,134 ... second bar 135, communication passage 138, 139, valve seat 151, first sealing material 152, second sealing material 155A, 155B, first through hole 156A, 156B, second through hole 160, check valve 170, exhaust valve 180. ... projection 182 ... opening 191 ... first valve housing 192 ... second valve housing

Claims (7)

A pump having a pump housing provided with a discharge hole;
A valve having a valve housing provided with a first vent hole, a second vent hole, and a third vent hole connected to the discharge hole;
A container connected to the second vent hole for storing gas flowing out of the second vent hole through the first vent hole;
A fluid control apparatus comprising: a heat sink having a facing portion facing the third vent hole and mounted on the pump housing. The valve has a valve body that constitutes a first valve chamber and a second valve chamber together with the valve housing,
The valve body has a state in which the second vent hole and the third vent hole are not connected based on the pressure of the first valve chamber and the pressure of the second valve chamber, and the second vent hole and the second vent hole, The fluid control device according to claim 1, wherein the fluid control device switches between a state in which the third vent hole is connected.   The fluid control device according to claim 1, wherein a tip of the facing portion is bent toward the valve housing.   4. The fluid control device according to claim 1, wherein a surface of the facing portion that faces the third ventilation hole is formed in an uneven shape. 5.   The fluid control device according to claim 1, wherein the facing portion is formed in a comb-teeth shape.   The fluid control device according to claim 1, wherein the pump includes a diaphragm and a piezoelectric element that flexibly vibrates the diaphragm.   The fluid control device according to claim 1, further comprising a control unit that measures blood pressure based on the pressure of the gas stored in the container.