JP2014077384A - Gas control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas control device capable of preventing a compressed gas charged in a gas storage portion from being unexpectedly discharged through an exhaust valve in operating a pump, and sufficiently discharging the compressed gas charged in the gas storage portion through the exhaust valve after stopping the operation of the pump.SOLUTION: A gas control device 100 includes a piezoelectric pump 101, a piezoelectric pump 201, and an exhaust valve 103. The piezoelectric pump 101, the piezoelectric pump 201 and a cuff 109 are connected in series. A discharge hole 55 of the piezoelectric pump 101 is communicated with a suction hole 52 of the piezoelectric pump 201. A discharge hole 55 of the piezoelectric pump 201 is communicated with the cuff 109. A first opening portion 37 of the exhaust valve 103 is communicated with the discharge hole 55 of the piezoelectric pump 101 and the suction hole 52 of the piezoelectric pump 201. A first region 39A and a second region 39B of the exhaust valve 103 are disposed in a state of satisfying a relationship of S1(P1-d1)>S2(P1+P2-d1-d2)-F3.

Description

  The present invention relates to a gas control device that transports gas.

  Conventionally, various gas control devices for transporting gas have been devised. For example, Patent Document 1 discloses a multistage compressor.

  FIG. 20 is a cross-sectional view of main parts of a multistage compressor 900 according to Patent Document 1. The multistage compressor 900 includes a low pressure side compression unit 903 (first pump), a high pressure side compression unit 916 (second pump), and an air tank 933 (gas storage unit). The low pressure side compression unit 903, the high pressure side compression unit 916, and the air tank 933 are connected in series.

  The low-pressure side compression unit 903 includes a suction chamber 912, a cylinder 904, a compression chamber 907, a discharge chamber 913, valves 914 and 915, and holes 910A, 905A, 905B, and 910B. A piston 906 is slidably provided in the cylinder 904.

  The suction chamber 912 communicates with the outside of the low-pressure side compression unit 903 through the hole 910A. The suction chamber 912 communicates with the compression chamber 907 through a hole 905A and a valve 914. The compression chamber 907 communicates with the discharge chamber 913 through the hole 905B and the valve 915. The discharge chamber 913 communicates with the suction chamber 923 of the high-pressure side compression unit 916 through the hole 910B, the pipe 931, and the hole 922A.

  The high-pressure side compression unit 916 includes a suction chamber 923, a cylinder 917, a compression chamber 920, a discharge chamber 924, valves 925 and 926, and holes 922A, 918A, 918B, and 922B. A piston 919 is slidably provided in the cylinder 917.

  The suction chamber 923 communicates with the compression chamber 920 through a hole 918A and a valve 925. The compression chamber 920 communicates with the discharge chamber 924 through a hole 918B and a valve 926. The discharge chamber 924 communicates with the air tank 933 through the hole 922 </ b> B and the pipe 932.

  In the above configuration, the low pressure side compression unit 903 performs a so-called pump operation, and the piston 906 reciprocates up and down in the cylinder 904. As a result, air outside the low pressure side compression unit 903 is sucked into the compression chamber 907 via the hole 910A, the suction chamber 912, and the hole 905A. The air in the compression chamber 907 is discharged from the hole 910 </ b> B through the hole 905 </ b> B and the discharge chamber 913, and flows into the suction chamber 923 of the high-pressure side compression unit 916 from the hole 922 </ b> A through the pipe 931.

  The high-pressure side compression unit 916 also performs a so-called pump operation, and the piston 919 reciprocates up and down in the cylinder 917. Thereby, the air in the suction chamber 923 is sucked into the compression chamber 920 through the hole 918A. Then, the air in the compression chamber 920 is discharged from the hole 922 </ b> B through the hole 918 </ b> B and the discharge chamber 924, and flows into the air tank 933 through the pipe 932. As a result, the air tank 933 is filled with air.

  In the multistage compressor 900, the pressure of the discharged air is increased by connecting two pumps (the low pressure side compression unit 903 and the high pressure side compression unit 916) in series.

JP 2006-183531 A

  The multistage compressor 900 is not provided with an exhaust mechanism that discharges the air filled in the air tank 33 by the operations of the low-pressure side compressor 903 (first pump) and the high-pressure side compressor 916 (second pump). Therefore, when the operations of the low-pressure side compression unit 903 and the high-pressure side compression unit 916 are stopped, the pressure in the compression chamber 920 of the high-pressure side compression unit 916 and the pressure in the air tank 933 are promptly transferred to the outside of the multistage compressor 900. It cannot be opened.

  Therefore, the inventor of the present application, as shown in FIG. 21, the piezoelectric pump 101 (first pump), the piezoelectric pump 201 (second pump), and a gas storage unit 959 that stores air discharged from the piezoelectric pump 201. And a gas control device 950 that includes a check valve 102 that prevents backflow of air from the gas storage unit 959 to the piezoelectric pump 201 and an exhaust valve 103 that discharges air from the gas storage unit 959.

  Specifically, the piezoelectric pump 101 has a suction hole 52, a pump chamber 45, a piezoelectric actuator 40, and a discharge hole 55. The structure of the piezoelectric pump 201 is the same as that of the piezoelectric pump 101. When the drive voltage is applied, the piezoelectric actuator 40 bends and vibrates. Thus, each of the piezoelectric pumps 101 and 201 sucks air into the pump chamber 45 through the suction hole 52 and discharges it from the discharge hole 55.

  Next, the exhaust valve 103 includes a lower valve housing 35, a diaphragm 39, and an upper valve housing 31. The lower valve housing 35 is provided with a first opening 37 that communicates with the discharge hole 55 of the piezoelectric pump 201. The upper valve casing 31 includes a second opening 32 communicating with the gas storage unit 959, a third opening 34 communicating with the outside of the gas control device 950, and the diaphragm 39 from the periphery of the second opening 32. A protruding valve seat 30 is provided. The diaphragm 39 is sandwiched between the lower valve housing 35 and the upper valve housing 31. A first valve chamber 36 is configured by the lower valve casing 35 and the diaphragm 39, and a second valve chamber 33 is configured by the diaphragm 39 and the upper valve casing 31.

  The exhaust valve 103 opens and closes when the diaphragm 39 contacts or separates from the valve seat 30.

  Next, the check valve 102 includes a lower valve housing 25, a diaphragm 29, and an upper valve housing 21. The lower valve housing 25 is provided with a first communication hole 27 that communicates with the discharge hole 55 of the piezoelectric pump 201 and a columnar protrusion 20 that protrudes toward the diaphragm 29. The upper valve housing 21 is provided with a second communication hole 24 communicating with the gas storage unit 959. The diaphragm 29 is sandwiched between the lower valve housing 25 and the upper valve housing 21. A third valve chamber 26 is configured by the lower valve casing 25 and the diaphragm 29, and a fourth valve chamber 23 is configured by the diaphragm 29 and the upper valve casing 21.

  The check valve 102 opens and closes due to the pressure difference between the third valve chamber 26 and the fourth valve chamber 23 such that the periphery of the hole 29 </ b> A in the diaphragm 29 contacts or separates from the protruding portion 20.

  The piezoelectric pump 101, the piezoelectric pump 201, the check valve 102, and the gas storage unit 959 are connected in series. The discharge hole 55 of the piezoelectric pump 101 is connected to the suction hole 52 of the piezoelectric pump 201. The discharge hole 55 of the piezoelectric pump 201 is connected to the first communication hole 27 of the check valve 102. The second communication hole 24 of the check valve 102 is connected to the gas storage unit 959.

  In the above configuration, the gas control device 950 also increases the pressure of the discharged air by connecting two pumps (piezoelectric pumps 101 and 201) in series. When the piezoelectric pumps 101 and 201 operate, air is sent from the piezoelectric pumps 101 and 201 to the gas storage unit 959 via the check valve 102, and the pressure (air pressure) in the gas storage unit 959 increases to the target pressure.

  Thereafter, when the operations of the piezoelectric pumps 101 and 201 are stopped, the air in the first valve chamber 36 of the exhaust valve 103 passes through the pump chamber 45 of the piezoelectric pump 201 and the pump chamber 45 of the piezoelectric pump 101. It is discharged from the suction hole 52. On the other hand, the pressure of the second opening 32 of the exhaust valve 103 is equal to the pressure of the air filled in the gas storage unit 959.

  As a result, in the exhaust valve 103, when the operations of the piezoelectric pumps 101 and 201 are stopped, the pressure in the first valve chamber 36 is lower than the pressure in the second opening 32. Therefore, in the exhaust valve 103, the diaphragm 39 is separated from the valve seat 30 and the second opening 32 and the third opening 34 communicate with each other via the second valve chamber 33. Thereby, the air filled in the gas storage unit 959 is rapidly discharged from the third opening 34 via the second opening 32 and the second valve chamber 33 of the exhaust valve 103.

  However, in each of the piezoelectric pumps 101 and 201, the smaller the diameter of the suction hole 52, the smaller the flow rate of air discharged from the pump chamber 45 to the outside of the pump chamber 45 through the suction hole 52. Therefore, the pressures in the respective pump chambers 45 of the piezoelectric pumps 101 and 201 do not decrease immediately after the operations of the piezoelectric pump 101 and the piezoelectric pump 201 stop, but gradually decrease.

  Therefore, the air pressure remains in the respective pump chambers 45 of the piezoelectric pumps 101 and 201 until a predetermined time (for example, 1 hour) elapses after the operation of the piezoelectric pump 101 and the piezoelectric pump 201 is stopped. .

  In such a case, after the piezoelectric pumps 101 and 201 stop operating in the gas control device 950, the pressure in the first valve chamber 36 becomes equal to the pressure remaining in the piezoelectric pump 201.

  Therefore, after the piezoelectric pumps 101 and 201 stop operating, the pressure of the gas storage unit 959 does not drop below the pressure remaining inside the piezoelectric pump 201. Therefore, the exhaust valve 103 is difficult to open, and the gas control device 950 has a problem that the air filled in the gas storage unit 959 is not sufficiently discharged through the exhaust valve 103.

  The object of the present invention is to prevent the gas filled in the gas storage part from being unintentionally discharged through the exhaust valve while the pump is operating, and after the pump stops operating, The object is to provide a gas control device that is easy to open.

  The gas control apparatus of the present invention has the following configuration in order to solve the above problems.

(1) a first pump having a first suction hole for gas, a first pump chamber through which the gas passes, and a first discharge hole for the gas;
The second suction hole has a second pump chamber through which the gas passes and the second discharge hole for the gas, and the second suction hole communicates with the first discharge hole to store the gas. A second pump in which the second discharge hole is connected to a gas storage unit;
Positioned between the first opening communicating with the second suction hole, the second opening connected to the gas storage section, the third opening, and the second opening and the third opening. A valve housing having a valve seat, a first valve chamber that divides the inside of the valve housing and communicates with the first opening, and a second that communicates with the second opening and the third opening. An exhaust valve having a valve chamber, and a valve body configured with the valve housing,
The pressure difference between the first suction hole and the first discharge hole during the operation of the first pump is P1, the pressure loss during the operation of the first pump is d1, and the second pressure during the operation of the second pump. The pressure difference between the suction hole and the second discharge hole is P2, the pressure loss during operation of the second pump is d2, the area of the first region of the valve body facing the first valve chamber is S1, the first 2 When the area of the second region of the valve body facing the opening is S2, the first region and the second region have a relationship of S1 (P1-d1)> S2 (P1 + P2-d1-d2). It is provided to satisfy.

  In this configuration, the gas is, for example, air. The gas storage unit is, for example, a cuff for measuring blood pressure. The third opening is opened to the atmosphere, for example.

  In this configuration, when the first and second pumps start operating, gas flows from the first suction hole into the first pump chamber. Then, the gas in the first pump chamber is discharged from the first discharge hole, flows into the second pump chamber from the second suction hole, and flows into the first valve chamber of the exhaust valve from the first opening.

  As a result, the gas is sent from the first and second pumps to the gas storage unit, and the pressure of the gas in the gas storage unit increases to the target pressure.

  Here, the first region and the second region of the exhaust valve are provided so as to satisfy the relationship of S1 (P1-d1)> S2 (P1 + P2-d1-d2). S1 (P1-d1) corresponds to the force F1 applied to the first region of the valve body. S2 (P1 + P2-d1-d2) corresponds to the force F2 applied to the second region of the valve body.

  That is, the first region and the second region of the exhaust valve are provided so as to satisfy the relationship of F1> F2. Therefore, according to this configuration, the exhaust valve can be prevented from opening unintentionally while the first and second pumps are operating. Therefore, according to this structure, it can prevent that the gas with which the gas storage part is filled is discharged | emitted via an exhaust valve, while the 1st, 2nd pump is operate | moving.

  Next, when the operation of the first and second pumps stops, the gas in the first valve chamber of the exhaust valve is discharged from the first suction hole via the first discharge hole and the first pump chamber of the first pump. The On the other hand, the pressure of the second opening of the exhaust valve is equal to the pressure of the gas filled in the gas storage unit.

  As a result, in the exhaust valve, when the operations of the first and second pumps are stopped, the pressure in the first valve chamber is lower than the pressure in the second opening. For this reason, in the exhaust valve, the valve body is separated from the valve seat, and the second opening and the third opening communicate with each other via the second valve chamber. As a result, the gas in the gas storage part is rapidly discharged from the third opening part via the second opening part and the second valve chamber of the exhaust valve.

  However, in each of the first and second pumps, the smaller the diameter of the suction hole, the smaller the flow rate of gas discharged from the pump chamber through the suction hole. For this reason, the pressures in the pump chambers of the first and second pumps do not decrease immediately after the first and second pumps stop operating, but gradually decrease. Therefore, air pressure remains in each pump chamber of the first and second pumps until a predetermined time (for example, 1 hour) elapses after the operation of the first and second pumps is stopped.

  Here, the first opening of the exhaust valve communicates with the discharge hole of the first pump and the suction hole of the second pump. Therefore, after the first and second pumps stop operating, the pressure in the first region of the valve body becomes equal to the pressure remaining in the first pump chamber.

  That is, after the operation of the first and second pumps is stopped, the exhaust valve is easier to open than when the pressure in the first region of the valve body is equal to the pressure remaining in the second pump chamber. Therefore, after the operation of the first and second pumps is stopped, the gas pressure in the gas storage unit is reduced to the pressure remaining in the first pump chamber. That is, after the operation of the first and second pumps is stopped, the gas filled in the gas storage unit is further discharged through the exhaust valve.

  Therefore, according to this configuration, while the first and second pumps are operating, the gas filled in the gas storage unit can be prevented from being unintentionally discharged through the exhaust valve. After the second pump stops operating, the exhaust valve is likely to open.

(2) The valve seat protrudes toward the valve body and contacts the valve body,
It is preferable that the third opening communicates with the outside of the valve housing.

  In this configuration, when the operation of the first and second pumps is stopped, the gas in the gas storage section passes from the third opening to the outside of the valve housing via the second opening and the second valve chamber of the exhaust valve. It is discharged rapidly.

(3) It is preferable that the said valve body has flexibility and the peripheral part of the said valve body is clamped by the said valve housing | casing.

  In this configuration, the exhaust valve opens and closes when the central portion located inside the peripheral edge of the valve body contacts or separates from the valve seat.

(4) A first communication hole that communicates with the second discharge hole, and a second communication hole that is connected to the gas storage unit, and the flow of gas from the gas storage unit to the second discharge hole. With check valve to prevent,
When the pressure loss of the check valve is B1, the first region and the second region are provided so as to satisfy the relationship of S1 (P1-d1)> S2 (P1 + P2-d1-d2-B1). It is preferable.

  In this configuration, S1 (P1-d1) corresponds to the force F1 applied to the first region of the valve body. S2 (P1 + P2-d1-d2-B1) corresponds to the force F2 applied to the second region of the valve body. That is, the first region and the second region of the exhaust valve are provided so as to satisfy the relationship of F1> F2. Therefore, even in this configuration, it is possible to prevent the gas filled in the gas storage unit from being unintentionally discharged through the exhaust valve while the first and second pumps are operating.

  In addition, since most of the gas filled in the gas storage unit can be discharged from the exhaust valve after the first and second pumps stop operating, the gas filled in the gas storage unit more quickly. Can be discharged.

(5) a first pump having a first suction hole for gas, a first pump chamber through which the gas passes, and a first discharge hole for the gas;
A t-th pump having a t-th suction hole for the gas, a t-th pump chamber through which the gas passes, and a t-th discharge hole for the gas, the t-th suction hole communicating with the t-th discharge hole; (T is an integer from 2 to n-1),
The gas has an nth suction hole, an nth pump chamber through which the gas passes, and an nth discharge hole for the gas. The nth suction hole communicates with the n-1th discharge hole to store the gas. An n-th pump (n is an integer of 3 or more) in which the n-th discharge hole is connected to the gas storage unit
A first opening communicating with the m-th suction hole (m is an integer of 2 or more and n or less), a second opening connected to the gas storage unit, a third opening, the second opening, and the A valve housing having a valve seat positioned between the third opening, a first valve chamber that divides the inside of the valve housing and communicates with the first opening, the second opening, An exhaust valve having a second valve chamber communicating with the third opening, and a valve body configured with the valve housing,
The pressure difference between the first suction hole and the first discharge hole during the operation of the first pump is P1, the pressure loss during the operation of the first pump is d1, and the n-th during the operation of the n-th pump. The pressure difference between the suction hole and the nth discharge hole is Pn, the pressure loss during operation of the nth pump is dn, the area of the first region of the valve body facing the first valve chamber is S1, the first When the area of the second region of the valve body facing the two openings is S2, the first region and the second region are

  It is preferable to be provided so as to satisfy the relationship.

  In this configuration, n pumps are connected in series.

  Even in this configuration, the first region and the second region of the exhaust valve are provided so as to satisfy the relationship of F1> F2 as in the case (1). Therefore, according to this configuration, the exhaust valve can be prevented from opening unintentionally while n pumps are operating. That is, according to this configuration, it is possible to prevent the gas filled in the gas storage unit from being discharged through the exhaust valve while the n pumps are operating.

  When the operation of the n pumps is stopped, the gas in the first valve chamber of the exhaust valve is the m-1 discharge hole, the m-1 pump chamber, and the m-1 suction hole of the m-1 pump. Then, the gas is discharged from the first suction hole via the first discharge hole of the first pump and the first pump chamber. On the other hand, the pressure of the second opening of the exhaust valve is equal to the pressure of the gas filled in the gas storage unit.

  As a result, in the exhaust valve, when the operation of the n pumps is stopped, the pressure in the first valve chamber is lower than the pressure in the second opening. For this reason, in the exhaust valve, the valve body is separated from the valve seat, and the second opening and the third opening communicate with each other via the second valve chamber. As a result, the gas in the gas storage part is rapidly discharged from the third opening part via the second opening part and the second valve chamber of the exhaust valve.

  Here, the first opening of the exhaust valve communicates with the m−1th discharge hole and the mth suction hole. Therefore, after the n pumps stop operating, the pressure in the first region of the valve body becomes equal to the pressure remaining in the m-1st pump chamber.

  That is, after the n pumps stop operating, the exhaust valve is more likely to open than when the pressure in the first region of the valve body is equal to the pressure remaining in the nth pump chamber. Therefore, after n pumps stop operation | movement, the pressure of the gas of a gas storage part falls to the pressure which remains in a m-1st pump chamber. That is, after the n pumps stop operating, the gas filled in the gas storage unit is further discharged through the exhaust valve.

  Therefore, according to this configuration, as in the case (1), the gas filled in the gas storage unit is prevented from being unintentionally discharged through the exhaust valve while n pumps are operating. The exhaust valve can be easily opened after the n pumps stop operating.

  According to the present invention, the gas filled in the gas storage unit can be prevented from being unintentionally exhausted through the exhaust valve while the pump is operating, and the exhaust valve is stopped after the pump stops operating. Becomes easier to open.

  In addition, according to the present invention, it is possible to prevent the gas filled in the gas storage unit from being unintentionally discharged through the exhaust valve while the n pumps are operating. After stopping the operation, the exhaust valve becomes easier to open.

It is a block diagram which shows the structure of the principal part of the gas control apparatus 100 which concerns on 1st Embodiment of this invention. It is a disassembled perspective view of the piezoelectric pump 101 shown in FIG. It is sectional drawing of the principal part of the piezoelectric pump 101 shown in FIG. It is a perspective view of the lower valve housing | casing 35 which comprises the exhaust valve 103 shown in FIG. FIG. 2 is a perspective view of an upper valve housing 31 that constitutes the exhaust valve 103 shown in FIG. 1. It is sectional drawing of the principal part of the exhaust valve 103 shown in FIG. It is explanatory drawing which shows the flow of air when the piezoelectric pump 101 shown in FIG. 1 is operate | moving. It is explanatory drawing which shows the flow of the air immediately after the piezoelectric pump 101 shown in FIG. 1 stopped operation | movement. It is a block diagram which shows the structure of the principal part of the gas control apparatus 200 which concerns on 2nd Embodiment of this invention. It is a perspective view of the lower valve housing | casing 25 which comprises the non-return valve 102 shown in FIG. FIG. 10 is a perspective view of an upper valve housing 21 constituting the check valve 102 shown in FIG. 9. It is explanatory drawing which shows the flow of air when the piezoelectric pumps 101 and 201 shown in FIG. 9 are operate | moving. It is explanatory drawing which shows the flow of air immediately after the piezoelectric pumps 101 and 201 shown in FIG. 9 stop operation | movement. It is a block diagram which shows the structure of the principal part of the gas control apparatus 300 which concerns on 3rd Embodiment of this invention. It is explanatory drawing which shows the flow of air when the piezoelectric pumps 101, 201, and 301 shown in FIG. 14 are operate | moving. It is explanatory drawing which shows the flow of the air immediately after the piezoelectric pump 101, 201, 301 shown in FIG. 14 stopped operation | movement. It is a block diagram which shows the structure of the principal part of the gas control apparatus 400 which concerns on 4th Embodiment of this invention. FIG. 18 is an explanatory diagram showing the air flow when the piezoelectric pumps 101, 201,..., 801 shown in FIG. It is explanatory drawing which shows the flow of the air immediately after the piezoelectric pumps 101, 201, ..., 801 shown in FIG. 3 is a cross-sectional view of a main part of a multistage compressor 900 according to Patent Document 1. FIG. It is a block diagram which shows the structure of the principal part of the gas control apparatus 950 which concerns on the comparative example of this invention.

<< First Embodiment >>
The gas control apparatus 100 according to the first embodiment of the present invention will be described below.
FIG. 1 is a block diagram illustrating a configuration of a main part of the gas control device 100 according to the first embodiment of the present invention. The gas control device 100 includes a piezoelectric pump 101, a piezoelectric pump 201, and an exhaust valve 103, and is connected to a cuff 109. The gas control device 100 is a device that measures blood pressure by filling the cuff 109 with air.

  The casing 110 of the gas control apparatus 100 has a connection port 106A to which the rubber tube 109A of the cuff 109 is connected, an inlet 107A for sucking air from the outside of the casing 110, and air filled in the cuff 109. And an exhaust port 107 </ b> B for discharging the air to the outside of the housing 110.

  The piezoelectric pump 101, the piezoelectric pump 201, and the cuff 109 are connected in series, and the exhaust valve 103 is connected in parallel between the piezoelectric pump 201 and the cuff 109.

  The piezoelectric pump 101 corresponds to the “first pump” of the present invention. The piezoelectric pump 201 corresponds to the “second pump” of the present invention.

  Here, the structure of the piezoelectric pump 101 and the exhaust valve 103 will be described in detail. First, the structure of the piezoelectric pump 101 will be described in detail with reference to FIGS. The structure of the piezoelectric pump 201 is the same as that of the piezoelectric pump 101.

  FIG. 2 is an exploded perspective view of the piezoelectric pump 101 shown in FIG. FIG. 3 is a cross-sectional view of the main part of the piezoelectric pump 101 shown in FIG.

  The piezoelectric pump 101 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, the reinforcing plate 43, the vibration plate unit 60, the piezoelectric element 42, the spacer 53B, the electrode conduction plate 70, the spacer 53C, and the cover plate 54 constitute a pump housing 80. ing. The internal space of the pump housing 80 corresponds to the pump chamber 45.

  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 materials constituting the reinforcing plate 43 and the diaphragm 41 so that an appropriate compressive stress remains in the piezoelectric element 42.

  A frame plate 61 is provided around the vibration plate 41. 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. The spacer 53A is provided to hold the piezoelectric actuator 40 with a certain gap from the flexible plate 51. The frame plate 61 is provided with an external terminal 63 for electrical connection.

  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. 2, 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.

  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 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. A discharge hole 55 is provided in the lid plate 54. The lid plate 54 covers the upper part of the piezoelectric actuator 40. The discharge hole 55 is not necessarily provided at the center of the lid plate 54.

  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 56 that is located inside the fixed portion 57 and faces the opening 92.

  The movable portion 56 can vibrate at substantially the same frequency as the piezoelectric actuator 40 due to air pressure fluctuation accompanying vibration of the piezoelectric actuator 40. The natural frequency of the movable portion 56 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, delayed by 90 °) 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.

  Therefore, when an AC drive voltage is applied to the external terminals 63 and 72, the piezoelectric actuator 40 bends and vibrates concentrically. Furthermore, the movable part 56 of the flexible plate 51 also vibrates with the vibration of the piezoelectric actuator 40. Thus, the piezoelectric pump 101 sucks air into the pump chamber 45 through the opening 92 and the suction hole 52. Further, the piezoelectric pump 101 discharges air in the pump chamber 45 from the discharge hole 55.

  At this time, in the piezoelectric pump 101, the peripheral portion of the piezoelectric actuator 40 is not substantially fixed. Therefore, according to the piezoelectric pump 101, loss due to vibration of the piezoelectric actuator 40 is small, and a high discharge pressure and a large discharge flow rate can be obtained while being small and low-profile.

Next, the structure of the exhaust valve 103 will be described in detail with reference to FIGS. 4, 5, and 6.
4 is a perspective view of the lower valve housing 35 constituting the exhaust valve 103 shown in FIG. FIG. 5 is a perspective view of the upper valve housing 31 constituting the exhaust valve 103 shown in FIG. 6 is a cross-sectional view of the main part of the exhaust valve 103 shown in FIG.

  The exhaust valve 103 includes a lower valve casing 35, a diaphragm 39, and an upper valve casing 31, and has a structure in which these are stacked in order.

  The diaphragm 39 corresponds to the “valve element” of the present invention. Further, the lower valve housing 35 and the upper valve housing 31 constitute the “valve housing” of the present invention.

  The lower valve casing 35 is provided with a first opening 37. The upper valve housing 31 is provided with a second opening 32, a third opening 34, and a valve seat 30 that protrudes from the periphery of the second opening 32 toward the diaphragm 39.

  The diaphragm 39 is formed of a flexible thin film. With the center of the diaphragm 39 in contact with the valve seat 30, the periphery of the diaphragm 39 is sandwiched between the upper valve housing 31 and the lower valve housing 35.

  Thus, the diaphragm 39 divides the inside of the upper valve housing 31 and the lower valve housing 35, and configures the ring-shaped first valve chamber 36 communicating with the first opening 37 together with the lower valve housing 35, A cylindrical second valve chamber 33 communicating with the third opening 34 is configured with the upper valve housing 31.

  The diaphragm 39 has a first region 39A facing the first valve chamber 36 and a second region 39B facing the second opening 32. For example, the diameter R1 of the first valve chamber 36 is 26 mm, and the diameter R2 of the second opening 32 is 1.5 mm.

  The pressure difference between the suction hole 52 and the discharge hole 55 during the operation of the piezoelectric pump 101 is P1, the pressure loss during the operation of the piezoelectric pump 101 is d1, and the suction hole 52 and the discharge hole 55 when the piezoelectric pump 201 is operated. The pressure difference is P2, the pressure loss during operation of the piezoelectric pump 201 is d2, the area of the first region 39A of the diaphragm 39 is S1, the area of the second region 39B of the diaphragm 39 is S2, and the valve seat 30 moves the diaphragm 39 The first region 39A and the second region 39B of the exhaust valve 103 satisfy the relationship of S1 (P1-d1)> S2 (P1 + P2-d1-d2) −F3, where F3 is a force pushing toward the one valve chamber 36. It is provided as follows. Since F3 can be set to 0 (N), when F3 becomes 0 (N), F3 may be omitted from this relational expression.

  Specifically, the radius of S1 is 13 mm (diameter R1 is 26 mm), the radius of S2 is 0.75 mm (diameter R2 is 1.5 mm), P1 is 20 kPa, P2 is 25 kPa, d1 is 1 kPa, and d2 is 1 kPa. In this case, 13 * 13 * π (20-1)> 0.75 * 0.75 * π (25-1) −F3, and 3211π> 13.5π−F3. Therefore, the first region 39A and the second region 39B of the exhaust valve 103 satisfy the relationship of S1 (P1-d1)> S2 (P1 + P2-d1-d2) -F3.

  In the above structure, the exhaust valve 103 opens and closes when the diaphragm 39 contacts or separates from the valve seat 30.

  Here, as shown in FIG. 1, the piezoelectric pump 101, the piezoelectric pump 201, and the cuff 109 are connected in series by pipes 81, 82, 83 and a rubber tube 109A. The piezoelectric pump 201 and the exhaust valve 103 are connected in parallel by pipes 82 and 83.

  Thus, the suction hole 52 of the piezoelectric pump 101 communicates with the outside of the housing 110 via the suction port 107A of the housing 110, and the discharge hole 55 of the piezoelectric pump 101 communicates with the suction hole 52 of the piezoelectric pump 201. ing. Further, the discharge hole 55 of the piezoelectric pump 201 communicates with the inside of the cuff 109 via the connection port 106 </ b> A of the housing 110.

  The first opening 37 of the exhaust valve 103 communicates with the discharge hole 55 of the piezoelectric pump 101 and the suction hole 52 of the piezoelectric pump 201. The second opening 32 of the exhaust valve 103 communicates with the discharge hole 55 of the piezoelectric pump 201 and communicates with the inside of the cuff 109 via the connection port 106 </ b> A of the housing 110. The third opening 34 of the exhaust valve 103 is connected to the exhaust port 106 </ b> B by a pipe 84 and communicates with the outside of the housing 110.

  As described above, by connecting two piezoelectric pumps having the same structure in series to the cuff 109, the maximum discharge pressure increases approximately twice as much as when one piezoelectric pump is connected to the cuff 109.

Next, the operation of the gas control device 100 during blood pressure measurement will be described.
FIG. 7 is an explanatory view showing the flow of air when the piezoelectric pumps 101 and 201 shown in FIG. 1 are operating.

  When the piezoelectric pumps 101 and 201 start operating, air outside the housing 110 is sucked from the suction port 107A and flows into the pump chamber 45 of the piezoelectric pump 101 from the suction hole 52. The air flowing into the pump chamber 45 is discharged from the discharge hole 55 of the piezoelectric pump 101 and flows into the pump chamber 45 of the piezoelectric pump 201 from the suction hole 52 and from the first opening 37 to the first valve of the exhaust valve 103. It flows into the chamber 36.

  As a result, the air outside the housing 110 is sent from the piezoelectric pumps 101 and 201 to the cuff 109, and the pressure (air pressure) in the cuff 109 increases to the target pressure.

  Here, S1 (P1-d1) corresponds to the force F1 applied to the first region 39A of the diaphragm 39. S2 (P1 + P2-d1-d2) corresponds to the force F2 applied to the second region 39B of the diaphragm 39. That is, the first region 39A and the second region 39B of the exhaust valve 103 are provided so as to satisfy the relationship of F1> F2-F3.

  Therefore, according to the gas control apparatus 100, the exhaust valve 103 can be prevented from opening unintentionally while the piezoelectric pumps 101 and 201 are operating. That is, according to the gas control apparatus 100, it is possible to prevent the air filled in the cuff 109 from being discharged through the exhaust valve 103 while the piezoelectric pumps 101 and 201 are operating.

  FIG. 8 is an explanatory diagram showing the flow of air immediately after the operation of the piezoelectric pumps 101 and 201 shown in FIG.

  Next, when the blood pressure measurement ends, the piezoelectric pumps 101 and 201 stop operating. Here, the volumes of the pump chamber 45 and the first valve chamber 36 of each of the piezoelectric pumps 101 and 201 are extremely smaller than the volume of air that can be accommodated in the cuff 109. Therefore, when the operations of the piezoelectric pumps 101 and 201 are stopped, the air in the first valve chamber 36 of the exhaust valve 103 flows from the suction port 107A via the discharge hole 55, the pump chamber 45, and the suction hole 52 of the piezoelectric pump 101. It is discharged outside the housing 110.

  On the other hand, the pressure in the second opening 32 of the exhaust valve 103 is equal to the pressure in the cuff 109. As a result, in the exhaust valve 103, when the operations of the piezoelectric pumps 101 and 201 are stopped, the pressure in the first valve chamber 36 is lower than the pressure in the second opening 32. Therefore, in the exhaust valve 103, the diaphragm 39 is separated from the valve seat 30 and the second opening 32 and the third opening 34 communicate with each other via the second valve chamber 33. As a result, the air in the cuff 109 is rapidly discharged from the exhaust port 106 </ b> B via the second opening 32, the second valve chamber 33, and the third opening 34.

  However, in each of the piezoelectric pumps 101 and 201, the smaller the diameter of the suction hole 52, the smaller the flow rate of air discharged from the pump chamber 45 to the outside of the pump housing 80 via the suction hole 52. In the gas control apparatus 100, since the diameter of the suction hole 52 is extremely small (for example, 5 μm), the flow rate of air discharged from the pump chamber 45 to the suction hole 52 is small.

  Therefore, the pressures in the respective pump chambers 45 of the piezoelectric pumps 101 and 201 do not decrease immediately after the piezoelectric pumps 101 and 201 stop operating, but gradually decrease. Therefore, air pressure remains in the respective pump chambers 45 of the piezoelectric pumps 101 and 201 until a predetermined time (for example, 1 hour) elapses after the operation of the piezoelectric pumps 101 and 201 is stopped.

  Therefore, in the gas control device 100, the first opening 37 of the exhaust valve 103 communicates with the discharge hole 55 of the piezoelectric pump 101 and the suction hole 52 of the piezoelectric pump 201. Therefore, after the operation of the piezoelectric pumps 101 and 201 stops, the pressure in the first region 39A of the diaphragm 39 becomes equal to the pressure remaining in the pump chamber 45 of the piezoelectric pump 101.

  That is, after the piezoelectric pumps 101 and 201 stop operating, the exhaust valve 103 is more likely to open than when the pressure in the first region 39A of the diaphragm 39 becomes equal to the pressure remaining in the pump chamber 45 of the piezoelectric pump 201. .

  Therefore, after the operation of the piezoelectric pumps 101 and 201 stops, the pressure of the cuff 109 decreases to the pressure remaining in the pump chamber 45 of the piezoelectric pump 101. In other words, in the gas control device 100, after the blood pressure measurement, the air filled in the cuff 109 is further discharged through the exhaust valve 103.

  Therefore, according to the gas control apparatus 100, the air filled in the cuff 109 can be prevented from being unintentionally discharged through the exhaust valve 103 while the piezoelectric pumps 101 and 201 are operating. After the operations of 101 and 201 stop, the exhaust valve 103 is easily opened.

<< Second Embodiment >>
Hereinafter, the gas control device 200 according to the second embodiment of the present invention will be described.

  FIG. 9 is a block diagram showing the configuration of the main part of the gas control device 200 according to the second embodiment of the present invention. FIG. 10 is a perspective view of the lower valve housing 25 constituting the check valve 102 shown in FIG. FIG. 11 is a perspective view of the upper valve housing 21 constituting the check valve 102 shown in FIG.

  The gas control device 200 is different from the gas control device 100 in that a check valve 102 and an exhaust valve 203 are provided. Other configurations are the same.

  Specifically, as shown in FIGS. 9 to 11, the check valve 102 includes a lower valve housing 25, a diaphragm 29, and an upper valve housing 21, and these are stacked in order.

  The lower valve housing 25 is provided with a first communication hole 27 and a columnar protruding portion 20 protruding toward the diaphragm 29 side. The upper valve housing 21 is provided with a second communication hole 24.

  The diaphragm 29 is formed of a flexible thin film. As shown in FIGS. 1 and 5, the diaphragm 29 is provided with a circular hole 29 </ b> A in the center of the region facing the protruding portion 20. The diameter of the hole 29 </ b> A is smaller than the diameter of the surface of the protruding portion 20 that contacts the diaphragm 29.

  The periphery of the diaphragm 39 is sandwiched between the upper valve housing 21 and the lower valve housing 25 in a state where the periphery of the hole 29A in the diaphragm 29 is in contact with the protruding portion 20. Thereby, the diaphragm 29 divides the inside of the upper valve housing 21 and the lower valve housing 25 and constitutes the ring-shaped third valve chamber 26 communicating with the first communication hole 27 together with the lower valve housing 25, A columnar fourth valve chamber 23 communicating with the second communication hole 24 is configured together with the upper valve housing 21.

  In the above structure, the check valve 102 is opened and closed by the periphery of the hole 29 </ b> A in the diaphragm 29 contacting or separating from the protruding portion 20 due to the pressure difference between the third valve chamber 26 and the fourth valve chamber 23. To do. The check valve 102 prevents the air in the cuff 109 from flowing backward from the discharge hole 55 of the piezoelectric pump 201 to the pump chamber 45.

  Next, the pressure difference between the suction hole 52 and the discharge hole 55 during the operation of the piezoelectric pump 101 is P1, the pressure loss during the operation of the piezoelectric pump 101 is d1, and the suction hole 52 and the discharge hole 55 during the operation of the piezoelectric pump 201. Is the pressure difference when the piezoelectric pump 201 is operated, the pressure loss is d2, the area of the first region 39A of the diaphragm 39 is S1, the area of the second region 39B of the diaphragm 39 is S2, and the pressure loss of the check valve 102 Is B1, and the force by which the valve seat 30 pushes the diaphragm 39 toward the first valve chamber 36 is F3, the first region 39A and the second region 39B of the exhaust valve 203 have S1 (P1-d1)> S2 (P1 + P2 -D1-d2-B1) -F3 is provided to satisfy the relationship. The other structure of the exhaust valve 203 is the same as that of the exhaust valve 103.

  Here, as shown in FIG. 9, the piezoelectric pump 101, the piezoelectric pump 201, the check valve 102, and the cuff 109 are connected in series by pipes 81, 82, 283, 284 and a rubber tube 109A.

  Thus, the suction hole 52 of the piezoelectric pump 101 communicates with the outside of the housing 110 via the suction port 107A of the housing 110, and the discharge hole 55 of the piezoelectric pump 101 communicates with the suction hole 52 of the piezoelectric pump 201. ing. Further, the discharge hole 55 of the piezoelectric pump 201 communicates with the first communication hole 27 of the check valve 102. The second communication hole 24 of the check valve 102 communicates with the inside of the cuff 109 via the connection port 106 </ b> A of the housing 110.

  The first opening 37 of the exhaust valve 203 communicates with the discharge hole 55 of the piezoelectric pump 101 and the suction hole 52 of the piezoelectric pump 201. Further, the second opening 32 of the exhaust valve 203 communicates with the second communication hole 24 of the check valve 102 and communicates with the inside of the cuff 109 via the connection port 106 </ b> A of the housing 110. The third opening 34 of the exhaust valve 203 communicates with the outside of the housing 110 through the exhaust port 106B.

Next, the operation of the gas control device 200 during blood pressure measurement will be described.
FIG. 12 is an explanatory diagram showing the flow of air when the piezoelectric pumps 101 and 201 shown in FIG. 9 are operating.

  When the piezoelectric pumps 101 and 201 start operating, air outside the housing 110 is sucked from the suction port 107A and flows into the pump chamber 45 of the piezoelectric pump 101 from the suction hole 52. The air flowing into the pump chamber 45 is discharged from the discharge hole 55 of the piezoelectric pump 101 and flows into the pump chamber 45 of the piezoelectric pump 201 from the suction hole 52 and from the first opening 37 to the first valve of the exhaust valve 203. It flows into the chamber 36.

  Further, the air that has flowed into the pump chamber 45 of the piezoelectric pump 201 is discharged from the discharge hole 55 and flows from the first communication hole 27 into the third valve chamber 26 of the check valve 102. As a result, the pressure in the third valve chamber 26 is increased in the check valve 202, and the periphery of the hole 29 </ b> A in the diaphragm 29 is separated from the projecting portion 20 to open the check valve 202.

  As a result, air outside the housing 110 is sent from the piezoelectric pumps 101 and 201 to the cuff 109 via the check valve 102, and the pressure (air pressure) in the cuff 109 increases to the target pressure.

  Here, S1 (P1-d1) corresponds to the force F1 applied to the first region 39A of the diaphragm 39. S2 (P1 + P2-d1-d2-B1) corresponds to the force F2 applied to the second region 39B of the diaphragm 39.

  That is, the first region 39A and the second region 39B of the exhaust valve 203 are provided so as to satisfy the relationship of F1> F2-F3. Therefore, also in the gas control apparatus 200, the exhaust valve 103 can be prevented from opening unintentionally while the piezoelectric pumps 101 and 201 are operating. Therefore, according to the gas control apparatus 200, it is possible to prevent the air filled in the cuff 109 from being discharged through the exhaust valve 203 while the piezoelectric pumps 101 and 201 are operating.

  FIG. 13 is an explanatory diagram showing the flow of air immediately after the operation of the piezoelectric pumps 101 and 201 shown in FIG.

  Next, when the blood pressure measurement ends, the piezoelectric pumps 101 and 201 stop operating. Here, the volumes of the pump chamber 45, the first valve chamber 36, and the third valve chamber 26 of the piezoelectric pumps 101 and 201 are extremely small compared to the volume of air that can be accommodated in the cuff 109.

  Therefore, when the operations of the piezoelectric pumps 101 and 201 are stopped, the air in the third valve chamber 26 of the check valve 102 is discharged from the discharge hole 55, the pump chamber 45, the suction hole 52, and the discharge hole of the piezoelectric pump 101. 55, the air is discharged from the suction port 107A to the outside of the housing 110 via the pump chamber 45 and the suction hole 52.

  Similarly, when the operations of the piezoelectric pumps 101 and 201 are stopped, the air in the first valve chamber 36 of the exhaust valve 203 passes through the discharge hole 55, the pump chamber 45, and the suction hole 52 of the piezoelectric pump 101, and the suction port 107A. To the outside of the housing 110.

  On the other hand, the pressure in the fourth valve chamber 23 of the check valve 102 and the second opening 32 of the exhaust valve 203 is equal to the pressure in the cuff 109. As a result, in the check valve 102, when the operations of the piezoelectric pumps 101 and 201 are stopped, the pressure in the third valve chamber 26 is lower than the pressure in the fourth valve chamber 23. For this reason, the periphery of the hole 29A in the diaphragm 29 comes into contact with the protruding portion 20, and the check valve 102 is closed.

  Similarly, in the exhaust valve 203, when the operations of the piezoelectric pumps 101 and 201 are stopped, the pressure in the first valve chamber 36 is lower than the pressure in the second opening 32. For this reason, in the exhaust valve 203, the diaphragm 39 is separated from the valve seat 30 and the second opening 32 and the third opening 34 communicate with each other via the second valve chamber 33. As a result, the air in the cuff 109 is rapidly discharged from the exhaust port 106 </ b> B via the second opening 32, the second valve chamber 33, and the third opening 34.

  Here, also in the gas control apparatus 200, the first opening 37 of the exhaust valve 203 communicates with the discharge hole 55 of the piezoelectric pump 101 and the suction hole 52 of the piezoelectric pump 201. Therefore, after the piezoelectric pumps 101 and 201 stop operating, the pressure in the first region 39A of the diaphragm 39 becomes equal to the pressure remaining in the pump chamber 45 of the piezoelectric pump 101.

  That is, after the piezoelectric pumps 101 and 201 stop operating, the exhaust valve 203 is easier to open than when the pressure in the first region 39A of the diaphragm 39 becomes equal to the pressure remaining in the pump chamber 45 of the piezoelectric pump 201. .

  Therefore, after the operation of the piezoelectric pumps 101 and 201 stops, the pressure of the cuff 109 decreases to the pressure remaining in the pump chamber 45 of the piezoelectric pump 101. That is, in the gas control device 200, after the blood pressure measurement, the air filled in the cuff 109 is further discharged through the exhaust valve 203.

  Therefore, according to the gas control apparatus 200, there exists an effect similar to the said gas control apparatus 100.

  As shown in FIG. 8, in the gas control apparatus 100 that does not include the check valve 102, the piezoelectric pumps 101 and 201 stop operating as the diameter of the discharge hole 55 and the suction hole 52 of the piezoelectric pump 201 are larger. After that, the air in the cuff 109 easily flows into the first valve chamber 36 of the exhaust valve 103 through the pump chamber 45 of the piezoelectric pump 201.

  On the other hand, the gas control apparatus 200 can discharge most of the gas filled in the cuff 109 from the exhaust valve 203 after the operation of the piezoelectric pumps 101 and 201 is stopped. The gas filled in 109 can be discharged.

  That is, the check valve 102 is effective in a gas control device in which the diameter of the discharge hole 55 and the diameter of the suction hole 52 of the piezoelectric pump 201 are large.

<< Third Embodiment >>
Hereinafter, the gas control device 300 according to the third embodiment of the present invention will be described.
FIG. 14 is a block diagram showing a configuration of main parts of a gas control device 300 according to the third embodiment of the present invention. The gas control device 300 is different from the gas control device 100 in that a piezoelectric pump 301 and an exhaust valve 303 are provided. Other configurations are the same.

Specifically, the structure of the piezoelectric pump 301 is the same as that of the piezoelectric pump 101.
The pressure difference between the suction hole 52 and the discharge hole 55 during the operation of the piezoelectric pump 101 is P1, the pressure loss during the operation of the piezoelectric pump 101 is d1, and the suction hole 52 and the discharge hole 55 when the piezoelectric pump 201 is operated. P2 is the pressure difference during operation of the piezoelectric pump 201, d2 is the pressure loss during operation of the piezoelectric pump 201, P3 is the pressure difference between the suction hole 52 and the discharge hole 55 during operation of the piezoelectric pump 301, and d3 is the pressure loss during operation of the piezoelectric pump 301. When the area of the first region 39A of the diaphragm 39 is S1, the area of the second region 39B of the diaphragm 39 is S2, and the force by which the valve seat 30 pushes the diaphragm 39 toward the first valve chamber 36 is F3, the exhaust valve 303 The first region 39A and the second region 39B are provided so as to satisfy the relationship of S1 (P1-d1)> S2 (P1 + P2 + P3-d1-d2-d3) -F3. The other structure of the exhaust valve 303 is the same as that of the exhaust valve 103.

  Here, as shown in FIG. 14, the piezoelectric pump 101, the piezoelectric pump 201, the piezoelectric pump 301, and the cuff 109 are connected in series by pipes 81, 82, 383, and 384 and a rubber tube 109A.

  Thus, the suction hole 52 of the piezoelectric pump 101 communicates with the outside of the housing 110 via the suction port 107A of the housing 110, and the discharge hole 55 of the piezoelectric pump 101 communicates with the suction hole 52 of the piezoelectric pump 201. ing. Further, the discharge hole 55 of the piezoelectric pump 201 communicates with the suction hole 52 of the piezoelectric pump 301. Further, the discharge hole 55 of the piezoelectric pump 301 communicates with the inside of the cuff 109 via the connection port 106 </ b> A of the housing 110.

  The first opening 37 of the exhaust valve 303 communicates with the discharge hole 55 of the piezoelectric pump 101 and the suction hole 52 of the piezoelectric pump 201. Further, the second opening 32 of the exhaust valve 303 communicates with the discharge hole 55 of the piezoelectric pump 301 and communicates with the inside of the cuff 109 via the connection port 106 </ b> A of the housing 110. The third opening 34 of the exhaust valve 303 communicates with the outside of the housing 110 through the connection port 106 </ b> A of the housing 110.

  As described above, connecting the three piezoelectric pumps having the same structure in series to the cuff 109 increases the maximum discharge pressure to about three times that when one piezoelectric pump is connected to the cuff 109. However, after the operation of the piezoelectric pumps 101, 201, 301 stops, the pressure remaining in the pump chamber 45 of the piezoelectric pump 301 also increases approximately three times the pressure remaining in the pump chamber 45 of the piezoelectric pump 101.

Next, the operation of the gas control device 300 during blood pressure measurement will be described.
FIG. 15 is an explanatory diagram showing the air flow when the piezoelectric pumps 101, 201, and 301 shown in FIG. 14 are operating.

  When the piezoelectric pumps 101, 201, and 301 start operating, air outside the housing 110 is sucked from the suction port 107 </ b> A and flows into the pump chamber 45 of the piezoelectric pump 101 from the suction hole 52. The air flowing into the pump chamber 45 is discharged from the discharge hole 55 of the piezoelectric pump 101 and flows into the pump chamber 45 of the piezoelectric pump 201 from the suction hole 52 and from the first opening 37 to the first valve of the exhaust valve 303. It flows into the chamber 36.

  Further, the air that has flowed into the pump chamber 45 of the piezoelectric pump 201 is discharged from the discharge hole 55 and flows into the pump chamber 45 of the piezoelectric pump 301 from the suction hole 52. Further, the air flowing into the pump chamber 45 of the piezoelectric pump 301 is discharged from the discharge hole 55 and sent to the cuff 109.

  As a result, the air outside the housing 110 is sent from the piezoelectric pumps 101, 201, 301 to the cuff 109, and the pressure (air pressure) in the cuff 109 increases to the target pressure.

  Here, S1 (P1-d1) corresponds to the force F1 applied to the first region 39A of the diaphragm 39. S2 (P1 + P2 + P3-d1-d2-d3) corresponds to the force F2 applied to the second region 39B of the diaphragm 39.

  That is, the first region 39A and the second region 39B of the exhaust valve 303 are provided so as to satisfy the relationship of F1> F2-F3. Therefore, also in the gas control device 300, the exhaust valve 303 can be prevented from opening unintentionally while the piezoelectric pumps 101, 201, 301 are operating. That is, according to the gas control device 300, the air filled in the cuff 109 can be prevented from being discharged through the exhaust valve 303 while the piezoelectric pumps 101, 201, and 301 are operating.

  FIG. 16 is an explanatory diagram showing the flow of air immediately after the operation of the piezoelectric pumps 101, 201, 301 shown in FIG.

  Next, when the blood pressure measurement ends, the piezoelectric pumps 101, 201, and 301 stop operating. Here, when the operation of the piezoelectric pumps 101, 201, 301 is stopped, the air in the first valve chamber 36 of the exhaust valve 303 is discharged from the discharge hole 55, the pump chamber 45, the piezoelectric pump 101, as in the first embodiment. Then, the air is discharged from the suction port 107A to the outside of the housing 110 via the suction hole 52.

  On the other hand, the pressure in the second opening 32 of the exhaust valve 303 is equal to the pressure in the cuff 109. As a result, in the exhaust valve 303, the pressure in the first valve chamber 36 is lower than the pressure in the second opening 32. Therefore, in the exhaust valve 303, the diaphragm 39 is separated from the valve seat 30 and the second opening 32 and the third opening 34 communicate with each other via the second valve chamber 33. As a result, the air in the cuff 109 is rapidly discharged from the exhaust port 106 </ b> B via the second opening 32, the second valve chamber 33, and the third opening 34.

  Here, also in the gas control device 300, the first opening 37 of the exhaust valve 303 communicates with the discharge hole 55 of the piezoelectric pump 101 and the suction hole 52 of the piezoelectric pump 201. Therefore, after the piezoelectric pumps 101, 201, 301 stop operating, the first region 39 </ b> A of the diaphragm 39 described above becomes equal to the pressure remaining in the pump chamber 45 of the piezoelectric pump 101.

  That is, after the operation of the piezoelectric pumps 101, 201, 301 is stopped, the exhaust valve 303 is extremely different from the case where the first region 39A of the diaphragm 39 becomes equal to the pressure remaining in the pump chamber 45 of the piezoelectric pump 301. It becomes easy to open.

  Therefore, after the operation of the piezoelectric pumps 101, 201, 301 stops, the pressure of the cuff 109 decreases to the pressure remaining in the pump chamber 45 of the piezoelectric pump 101. That is, in the gas control device 300, after the blood pressure measurement, the air filled in the cuff 109 is further discharged through the exhaust valve 303.

  Therefore, according to the gas control device 300, the same effect as the gas control device 100 can be obtained.

<< 4th Embodiment >>
Hereinafter, the gas control apparatus 400 which concerns on 4th Embodiment of this invention is demonstrated.
FIG. 17 is a block diagram showing a configuration of main parts of a gas control device 400 according to the fourth embodiment of the present invention. The gas control device 400 is different from the gas control device 100 in that n piezoelectric pumps having the same structure are connected in series and an exhaust valve 403 is provided. n is an integer of 4 or more. Other configurations are the same.

  In FIG. 17, the piezoelectric pump 101 is a first stage piezoelectric pump, the piezoelectric pump 201 is a second stage piezoelectric pump, and the piezoelectric pump 801 is an nth stage piezoelectric pump. In FIG. 17, the piezoelectric pumps from the third stage to the (n−1) th stage are not shown.

  More specifically, the structure of the piezoelectric pump at the t stage (t is an integer from 2 to n−1) is the same as the structure of the piezoelectric pump 101 at the first stage. Therefore, the t-stage piezoelectric pump includes a t-th suction hole 52, a t-th pump chamber 45, and a t-th discharge hole 55. Similarly, the structure of the n-th stage piezoelectric pump 801 is the same as the structure of the first-stage piezoelectric pump 101. Therefore, the nth stage piezoelectric pump 801 has an nth suction hole 52, an nth pump chamber 45, and an nth discharge hole 55.

  The pressure difference between the suction hole 52 and the discharge hole 55 during the operation of the piezoelectric pump 101 is P1, the pressure loss during the operation of the piezoelectric pump 101 is d1, and the suction hole 52 and the discharge hole 55 when the piezoelectric pump 801 is operated. Pn, pressure loss during operation of the piezoelectric pump 801, dn, the area of the first region 39A of the diaphragm 39 is S1, the area of the second region 39B of the diaphragm 39 is S2, and the valve seat 30 is the diaphragm 39. When the force pushing toward the one valve chamber 36 is F3, the first region 39A and the second region 39B of the exhaust valve 403 are

  It is provided to satisfy the relationship. The other structure of the exhaust valve 403 is the same as that of the exhaust valve 103. Since F3 can also be set to 0 (N), when F3 becomes 0 (N), F3 may be omitted from Equation 2.

  Here, as shown in FIG. 17, the piezoelectric pumps 101, 201,..., 801 and the cuff 109 are connected in series by pipes 81, 82, 384 and a rubber tube 109A.

  Therefore, the suction hole 52 of the piezoelectric pump 101 communicates with the outside of the housing 110 via the suction port 107 </ b> A of the housing 110. Further, the discharge hole 55 of the t-1 stage piezoelectric pump communicates with the suction hole 52 of the t stage piezoelectric pump. Further, the discharge hole 55 of the (n−1) th stage piezoelectric pump communicates with the suction hole 52 of the nth stage piezoelectric pump 801. Further, the discharge hole 55 of the nth stage piezoelectric pump 801 communicates with the inside of the cuff 109 via the connection port 106 </ b> A of the housing 110.

  The first opening 37 of the exhaust valve 403 communicates with the discharge hole 55 of the piezoelectric pump 101 and the suction hole 52 of the piezoelectric pump 201. Further, the second opening 32 of the exhaust valve 403 communicates with the discharge hole 55 of the piezoelectric pump 801 and communicates with the inside of the cuff 109 via the connection port 106 </ b> A of the housing 110. The third opening 34 of the exhaust valve 403 communicates with the outside of the housing 110 through the exhaust port 106 </ b> B of the housing 110.

  As described above, by connecting n piezoelectric pumps having the same structure in series to the cuff 109, the maximum discharge pressure is increased to about n times that when one piezoelectric pump is connected to the cuff 109. However, after the operation of the piezoelectric pumps 101, 201,... 801 stops, the pressure remaining in the pump chamber 45 of the piezoelectric pump 801 also increases to about n times the pressure remaining in the pump chamber 45 of the piezoelectric pump 101. To do.

Next, the operation of the gas control device 400 during blood pressure measurement will be described.
FIG. 18 is an explanatory diagram showing the flow of air when the piezoelectric pumps 101, 201,..., 801 shown in FIG.

  When the piezoelectric pumps 101, 201,... 801 start operating, air outside the housing 110 is sucked from the suction port 107 </ b> A and flows into the pump chamber 45 of the piezoelectric pump 101 from the suction hole 52. The air flowing into the pump chamber 45 is discharged from the discharge hole 55 of the piezoelectric pump 101 and flows into the pump chamber 45 of the piezoelectric pump 201 from the suction hole 52 and from the first opening 37 to the first valve of the exhaust valve 403. It flows into the chamber 36.

  Further, the air flowing into the pump chamber 45 of the piezoelectric pump 201 is discharged from the discharge hole 55, passes through the pump chamber 45 of the piezoelectric pump from the third stage to the (n−1) th stage, and passes through the suction hole 52 of the piezoelectric pump 801. It flows into the pump chamber 45 of the pump 801. Further, the air flowing into the pump chamber 45 of the piezoelectric pump 801 is discharged from the discharge hole 55 and sent to the cuff 109.

  As a result, air outside the housing 110 is sent from the piezoelectric pumps 101, 201,..., 801 to the cuff 109, and the pressure (air pressure) in the cuff 109 increases to the target pressure.

  Note that the first region 39A and the second region 39B of the exhaust valve 403 are provided so as to satisfy the relationship of Expression 2 as described above. That is, the first region 39A and the second region 39B of the exhaust valve 403 are provided so as to satisfy the relationship of F1> F2-F3.

  Therefore, also in the gas control device 400, the exhaust valve 403 can be prevented from opening unintentionally while the piezoelectric pumps 101, 201,. That is, according to the gas control device 400, the air filled in the cuff 109 is prevented from being discharged through the exhaust valve 403 while the piezoelectric pumps 101, 201,. it can.

  FIG. 19 is an explanatory diagram showing the air flow immediately after the operation of the piezoelectric pumps 101, 201,..., 801 shown in FIG.

  Next, when the blood pressure measurement is completed, the operation of the piezoelectric pumps 101, 201,. Here, when the operations of the piezoelectric pumps 101, 201,..., 801 are stopped, the air in the first valve chamber 36 of the exhaust valve 403 is discharged from the discharge holes 55 of the piezoelectric pump 101, as in the first embodiment. The air is discharged from the suction port 107 </ b> A to the outside of the housing 110 via the pump chamber 45 and the suction hole 52.

  On the other hand, the pressure in the second opening 32 of the exhaust valve 403 is equal to the pressure in the cuff 109. As a result, in the exhaust valve 403, the pressure in the first valve chamber 36 is lower than the pressure in the second opening 32. For this reason, in the exhaust valve 403, the diaphragm 39 is separated from the valve seat 30 and the second opening 32 and the third opening 34 communicate with each other via the second valve chamber 33. As a result, the air in the cuff 109 is rapidly discharged from the exhaust port 106 </ b> B via the second opening 32, the second valve chamber 33, and the third opening 34.

  Here, also in the gas control device 400, the first opening 37 of the exhaust valve 403 communicates with the discharge hole 55 of the piezoelectric pump 101 and the suction hole 52 of the piezoelectric pump 201. Therefore, after the operation of the piezoelectric pumps 101, 201,..., 801 stops, the first region 39A of the diaphragm 39 becomes equal to the pressure remaining in the pump chamber 45 of the first-stage piezoelectric pump 101.

  That is, after the piezoelectric pumps 101, 201,... 801 stop operating, the pressure in the first region 39A of the diaphragm 39 becomes equal to the pressure remaining in the pump chamber 45 of the nth stage piezoelectric pump 801. The exhaust valve 403 is much easier to open than

  Therefore, after the operation of the piezoelectric pumps 101, 201,... 801 stops, the pressure of the cuff 109 decreases to the pressure remaining in the pump chamber 45 of the piezoelectric pump 101. That is, in the gas control device 400, after the blood pressure measurement, the air filled in the cuff 109 is further discharged through the exhaust valve 403.

  Therefore, as shown in FIG. 17, the gas control device 400 in which n piezoelectric pumps are connected in series has the same effect as the gas control device 100.

  In the present embodiment, the first opening 37 of the exhaust valve 403 communicates with the discharge hole 55 of the first-stage piezoelectric pump 101 and the suction hole 52 of the second-stage piezoelectric pump 201. It is not limited to. In implementation, the first opening 37 of the exhaust valve 403 may communicate with the discharge hole 55 of the m−1th stage piezoelectric pump and the suction hole 52 of the mth stage piezoelectric pump. Here, m is an integer of 2 or more and n or less.

  In this configuration, after the piezoelectric pumps 101, 201,..., 801 stop operating, the first region 39A of the diaphragm 39 described above is the pressure remaining in the pump chamber 45 of the m−1th stage piezoelectric pump. Will be equal.

  That is, after the piezoelectric pumps 101, 201,... 801 stop operating, the pressure in the first region 39A of the diaphragm 39 becomes equal to the pressure remaining in the pump chamber 45 of the nth stage piezoelectric pump 801. The exhaust valve 403 is easier to open than

  Therefore, after the operation of the piezoelectric pumps 101, 201,..., 801 stops, the pressure of the cuff 109 decreases to the pressure remaining in the pump chamber 45 of the m−1 stage piezoelectric pump. That is, even in this configuration, after the blood pressure measurement, the air filled in the cuff 109 is further discharged through the exhaust valve 403.

<< Other Embodiments >>
In each of the above embodiments, air is used as a gas, but the present invention is not limited to this. The gas can be applied even if it is a gas other than air.

  Moreover, in each said embodiment, although the cuff is used as a gas storage part, it does not restrict to this. The gas storage unit is applicable even if it is other than the cuff.

  In each of the above embodiments, the piezoelectric element 42 is provided as a pump drive source, but the present invention is not limited to this. For example, a pump that operates by electromagnetic drive may be used.

  In each of the above embodiments, a unimorph type piezoelectric vibrator is used, but the present invention is not limited to this. A bimorph type piezoelectric vibrator in which the piezoelectric elements 42 are provided on both surfaces of the vibration plate 41 may be used.

  Moreover, in each said embodiment, although the piezoelectric element 42 consists of lead zirconate titanate ceramics, it is not restricted to this. For example, it may be made of a lead-free piezoelectric ceramic piezoelectric material such as potassium sodium niobate and alkali niobate ceramics.

  In each of the above embodiments, the disk-shaped piezoelectric actuator 40 is used, but the present invention is not limited to this. For example, the shape of the piezoelectric actuator 40 may be a rectangular plate shape, a polygonal plate shape, or an elliptical plate shape.

  Further, in each of the above embodiments, the example in which the flexible plate 51 bends and vibrates with the bending vibration of the piezoelectric actuator 40 has been described, but the present invention is not limited to this. In implementation, only the piezoelectric actuator 40 may bend and vibrate, and the flexible plate 51 may not necessarily bend and vibrate with the bending vibration of the piezoelectric actuator 40.

  In each of the above embodiments, the exhaust valves 103, 203, 303, and 403 have the second opening 32 connected to the cuff 109 and the third opening 34 connected to the exhaust port 106B. 34 may be connected to the cuff 109 with the second opening 32 disposed at the position of the second opening 32, and may be connected to the exhaust port 106 </ b> B with the second opening 32 disposed at the position of the third opening 34. In this connection method, even when the pressure of the cuff 109 fluctuates due to body movement or the like, there is an effect that unintended exhaust is hardly generated.

  Further, in each of the above embodiments, the cuff 109 has one connection port 106A, and the pump and the exhaust valve are connected to the cuff 109 through a common pipe 83, but this is not restrictive. For example, the cuff 109 may have two connection ports, and the pump and the exhaust valve may be connected by separate pipes.

  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.

20 ... Projection 21 ... Upper valve housing 23 ... Fourth valve chamber 24 ... Second communication hole 25 ... Lower valve housing 26 ... Third valve chamber 27 ... First communication hole 29 ... Diaphragm 29A ... Hole 30 ... Valve Seat 31 ... Upper valve housing 32 ... Second opening 33 ... Air tank 34 ... Third opening 35 ... Lower valve housing 36 ... First valve chamber 37 ... First opening 39 ... Diaphragm 39A ... First region 39B ... 2nd area | region 40 ... Piezoelectric actuator 41 ... Vibrating plate 42 ... Piezoelectric element 43 ... Reinforcement plate 45 ... Pump chamber 51 ... Flexible plate 52 ... Suction hole 53A, 53B, 53C ... Spacer 54 ... Cover plate 55 ... Discharge hole 56 ... Movable portion 57 ... fixed portion 60 ... diaphragm unit 61 ... frame plate 62 ... connecting portion 63 ... external terminal 70 ... electrode conduction plate 71 ... frame portion 72 ... external terminal 73 ... internal terminal 80 ... pump housings 81, 82, 83, 84, 283, 284, 383, 3 4 ... Piping 91 ... Substrate 92 ... Openings 100, 200, 300, 400 ... Gas control devices 101, 201, 301, 801 ... Piezoelectric pump 102 ... Check valves 103, 203, 303, 403 ... Exhaust valve 106A ... Connection port 106B ... Exhaust port 107A ... Suction port 107B ... Exhaust port 109 ... Cuff 109A ... Rubber tube 110 ... Case 202 ... Check valve 900 ... Multi-stage compressor 903 ... Low pressure side compressor 904 ... Cylinders 905A, 905B ... Hole 906 ... Piston 907 ... Compression chamber 910A, 910B ... Hole 912 ... Suction chamber 913 ... Discharge chamber 914, 915 ... Valve 916 ... High pressure side compression part 917 ... Cylinder 918A, 918B ... Hole 919 ... Piston 920 ... Compression chamber 922A, 922B ... Hole 923 ... Suction chamber 924 ... Discharge chambers 925 and 926 ... Valves 931 and 932 ... Pipe 933 ... Air tank 950 ... Body controller 959 ... gas storage unit

Claims (5)

A first pump having a first suction hole for gas, a first pump chamber through which the gas passes, and a first discharge hole for the gas;
The second suction hole has a second pump chamber through which the gas passes and the second discharge hole for the gas, and the second suction hole communicates with the first discharge hole to store the gas. A second pump in which the second discharge hole is connected to a gas storage unit;
Positioned between the first opening communicating with the second suction hole, the second opening connected to the gas storage section, the third opening, and the second opening and the third opening. A valve housing having a valve seat, a first valve chamber that divides the inside of the valve housing and communicates with the first opening, and a second that communicates with the second opening and the third opening. An exhaust valve having a valve chamber, and a valve body configured with the valve housing,
The pressure difference between the first suction hole and the first discharge hole during the operation of the first pump is P1, the pressure loss during the operation of the first pump is d1, and the second pressure during the operation of the second pump. The pressure difference between the suction hole and the second discharge hole is P2, the pressure loss during operation of the second pump is d2, the area of the first region of the valve body facing the first valve chamber is S1, the first 2 When the area of the second region of the valve body facing the opening is S2, the first region and the second region have a relationship of S1 (P1-d1)> S2 (P1 + P2-d1-d2). Gas control device provided to fill. The valve seat protrudes toward the valve body and contacts the valve body;
The gas control device according to claim 1, wherein the third opening communicates with the outside of the valve housing.   The gas control device according to claim 1, wherein the valve body has flexibility, and a peripheral portion of the valve body is sandwiched between the valve housings. A first check hole that communicates with the second discharge hole, and a second communication hole connected to the gas storage section, and a check that prevents a gas flow from the gas storage section to the second discharge hole. With a valve,
When the pressure loss of the check valve is B1, the first region and the second region are provided so as to satisfy the relationship of S1 (P1-d1)> S2 (P1 + P2-d1-d2-B1). The gas control device according to any one of claims 1 to 3. A first pump having a first suction hole for gas, a first pump chamber through which the gas passes, and a first discharge hole for the gas;
A t-th pump having a t-th suction hole for the gas, a t-th pump chamber through which the gas passes, and a t-th discharge hole for the gas, the t-th suction hole communicating with the t-th discharge hole; (T is an integer from 2 to n-1),
The gas has an nth suction hole, an nth pump chamber through which the gas passes, and an nth discharge hole for the gas. The nth suction hole communicates with the n-1th discharge hole to store the gas. An n-th pump (n is an integer of 3 or more) in which the n-th discharge hole is connected to the gas storage unit
A first opening communicating with the m-th suction hole (m is an integer of 2 or more and n or less), a second opening connected to the gas storage unit, a third opening, the second opening, and the A valve housing having a valve seat positioned between the third opening, a first valve chamber that divides the inside of the valve housing and communicates with the first opening, the second opening, An exhaust valve having a second valve chamber communicating with the third opening, and a valve body configured with the valve housing,
The pressure difference between the first suction hole and the first discharge hole during the operation of the first pump is P1, the pressure loss during the operation of the first pump is d1, and the n-th during the operation of the n-th pump. The pressure difference between the suction hole and the nth discharge hole is Pn, the pressure loss during operation of the nth pump is dn, the area of the first region of the valve body facing the first valve chamber is S1, the first When the area of the second region of the valve body facing the two openings is S2, the first region and the second region are
A gas control device provided to satisfy the relationship.