JP7444331B2 - Fluid control device and its control method - Google Patents

Description

The present invention relates to a fluid control device and a control method thereof.

Fluid control devices have been developed that include piezoelectric pumps and control circuits. International Publication No. 2019/198305 (Patent Document 1) describes using a fluid control device by connecting a plurality of piezoelectric pumps in series in order to improve performance, for example, pressure. More specifically, in Patent Document 1, a first piezoelectric pump and a second piezoelectric pump are connected in series in a fluid control device.

International Publication No. 2019/198305

However, a fluid control device that uses two piezoelectric pumps in series has a longer flow path than a fluid control device that uses one piezoelectric pump, so there is a risk of foreign matter flowing from the upstream side or coming off from the inner wall of the flow path. There is a high possibility that contamination will occur in the flow path due to foreign objects. When contamination occurs in the flow path, a blockage state occurs in the flow path, the temperature of the piezoelectric pump increases, and the possibility of failure such as cracking of the piezoelectric element of the piezoelectric pump increases.

An object of the present disclosure is to provide a technique for avoiding failure of a piezoelectric pump due to blockage in a flow path.

A fluid control device according to an embodiment of the present disclosure includes a first flow path, a first piezoelectric pump connected to one end of the first flow path, a second piezoelectric pump, and one end connected to the first piezoelectric pump. , the other end connected to the second piezoelectric pump, a third flow path having one end connected to the second piezoelectric pump, and a first branch path branched from the first flow path. a first valve provided in the first branch passage for switching communication/non-communication between the first passage and the outside; a second branch passage branched from the second passage; and a first valve provided in the second branch passage; , a second valve that switches communication/non-communication between the second flow path and the outside, a control unit that controls driving of the first piezoelectric pump and the second piezoelectric pump, and opening and closing of the first valve and the second valve; , prepare. The control unit includes a first mode in which the first valve is closed, the first piezoelectric pump is driven, the second valve is opened, and the second piezoelectric pump is stopped. A second mode in which the first valve is closed, the first piezoelectric pump is driven, the second valve is closed, and the second piezoelectric pump is further driven; A specific pattern control including a third mode in which the drive of the piezoelectric pump is stopped, the second valve is opened, and the drive of the second piezoelectric pump is further stopped is implemented.

In a method for controlling a fluid control device according to an embodiment of the present disclosure, the fluid control device includes a first flow path, a first piezoelectric pump connected to one end of the first flow path, and a second piezoelectric pump connected to one end of the first flow path. a second flow path connected to the first piezoelectric pump and the other end connected to the second piezoelectric pump; a third flow path connected to the second piezoelectric pump at one end; and a first branch path branched from the first flow path. a first valve provided in the first branch passage for switching communication/non-communication between the first passage and the outside; a second branch passage branched from the second passage; and a first valve provided in the second branch passage; , a second valve that switches communication/non-communication between the second flow path and the outside. The control method includes the steps of implementing a first mode in which a first valve is closed, a first piezoelectric pump is driven, a second valve is opened, and further, driving of the second piezoelectric pump is stopped; , closing the first valve, driving the first piezoelectric pump, closing the second valve, and further driving the second piezoelectric pump, implementing a second mode; a third mode in which the valve is opened, the driving of the first piezoelectric pump is stopped, the second valve is opened, and the driving of the second piezoelectric pump is stopped.

According to the present disclosure, contamination generated in the main flow path is discharged from the first valve or the second valve by specific pattern control, thereby avoiding malfunctions in the piezoelectric pump due to blockage in the flow path. Ru.

FIG. 1 is a schematic diagram for explaining the configuration of a nebulizer according to an embodiment. FIG. 1 is a schematic diagram showing the configuration of a pump unit according to an embodiment. FIG. 3 is a block diagram for explaining control of the pump unit according to the embodiment. FIG. 3 is a diagram illustrating an example of the content of specific pattern control. 5 is a flowchart of an example of a process for controlling the operation of the pump unit 10. FIG.

Below, a fluid control device according to the present embodiment will be described in detail with reference to the drawings. Note that the same reference numerals in the figures indicate the same or corresponding parts.

(Embodiment)
In the following embodiment, an example will be described in which a pump unit (fluid control device) in which two piezoelectric pumps are connected in series is used in a nebulizer. A nebulizer is a device that allows patients suffering from asthma or other conditions to inhale medicinal solutions orally, and atomizes the medicinal solution using a powerful airflow created by a pump unit. The device in which the pump unit is used is not limited to a nebulizer. The pump unit may be used, for example, in a discharge type device such as an aroma diffuser or a humidifier, or may be used in a suction type device such as a nasal aspirator.

FIG. 1 is a schematic diagram for explaining the configuration of a nebulizer 1 according to an embodiment. The nebulizer 1 includes a pump unit 10, an air nozzle 20, an atomizing nozzle 30, a drug tank 40, and a mouthpiece 50. The patient P holds the tip of the mouthpiece 50 in his mouth and inhales the atomized drug solution discharged from the tip.

The pump unit 10 is constructed by connecting two piezoelectric pumps (u piezoelectric pump 12 and d piezoelectric pump 14, which will be described later with reference to FIG. 2) in series to improve its performance (e.g., pressure). . A piezoelectric pump produces compressed air. By using a piezoelectric pump, the pump unit 10 can be reduced in size and weight compared to a pump using a motor. Although not shown, the piezoelectric pump has a piezoelectric element and a pump chamber inside the housing, and the volume and pressure of the pump chamber are varied by displacement of the piezoelectric element due to driving, thereby conveying fluid. The detailed configuration of the pump unit 10 will be described later.

The air nozzle 20 sends compressed air produced by the pump unit 10 toward the atomization nozzle 30. At the tip of the atomizing nozzle 30, a negative pressure is generated by the strong air flow created by the air nozzle 20, and the chemical liquid is sucked up from the chemical liquid tank 40 through the piping 42. The medicinal liquid sucked up to the tip of the atomizing nozzle 30 is atomized by the air flow from the air nozzle 20, and is delivered to the patient's P's oral cavity through the mouthpiece 50.

Next, the pump unit 10 will be described in detail with reference to the drawings. FIG. 2 is a schematic diagram showing the configuration of the pump unit 10 according to the embodiment. FIG. 3 is a block diagram for explaining control of the pump unit 10 according to the embodiment.

As shown in FIG. 2, the pump unit 10 includes a first flow path 11, a u piezoelectric pump 12 (first piezoelectric pump), a second flow path 13, and a d piezoelectric pump 14 (second piezoelectric pump). , and a third flow path 15. The first flow path 11 is a flow path provided on the upstream side that takes in air. The u piezoelectric pump 12 is connected to the downstream side of the first flow path 11. The second flow path 13 is a flow path that connects the u piezoelectric pump 12 and the d piezoelectric pump 14. The d piezoelectric pump 14 is connected in series to the u piezoelectric pump 12. The third flow path 15 is a flow path connected to the d piezoelectric pump 14 and provided on the downstream side.

The pump unit 10 can provide higher pressure by connecting the u piezoelectric pump 12 and the d piezoelectric pump 14 in series. However, since the u piezoelectric pump 12 and the d piezoelectric pump 14 vibrate their piezoelectric elements to compress air, the u piezoelectric pump 12 and the d piezoelectric pump 14 themselves generate heat. In particular, the temperature of the d piezoelectric pump 14 on the downstream side to which air heated by the heat generated by the u piezoelectric pump 12 is sent increases further. Furthermore, in the pump unit 10, when contamination occurs in the flow path, the flow path becomes blocked and the air flow becomes stagnant, causing the temperatures of the u piezoelectric pump 12 and the d piezoelectric pump 14 to rise further. Become. When the temperature of the u piezoelectric pump 12 and the d piezoelectric pump 14 becomes high, problems such as cracks occurring in the piezoelectric elements occur.

Therefore, it is desirable for the pump unit 10 to detect whether or not a blockage state has occurred in the flow path, but if a new sensor or the like for detecting contamination is provided, manufacturing costs will increase. has a big disadvantage. In this embodiment, a configuration will be described in which it is possible to easily detect whether or not a blockage state has occurred in the flow path in the pump unit 10 without providing a new sensor or the like for detecting contamination. .

Furthermore, in this embodiment, the pump unit 10 not only detects whether or not a blockage state has occurred in the flow path, but also has a configuration that discharges contamination that has occurred in the flow path in order to eliminate the blockage state. It also has Specifically, as shown in FIG. 2, the pump unit 10 includes a first branch channel 16 connected to the first channel 11 and connected to the outside of the channel, and a u-valve 17 (a first branch channel) provided in the first branch channel 16. 1 valve), a second branch path 18 connected to the second flow path 13 and connected to the outside of the flow path, and a d valve 19 (second valve) provided in the second branch path 18. Note that the pump unit 10 does not need to have a configuration for discharging contamination.

As shown in FIG. 3, the pump unit 10 includes a control circuit 100 that can control the driving of the u piezoelectric pump 12 and the d piezoelectric pump 14, and the opening and closing of the u valve 17 and the d valve 19, and the u piezoelectric pump 12. and a current sensor 200 (detection unit) that detects the current of each of the piezoelectric pumps 14. The nebulizer 1 has a power source (not shown) that supplies the power necessary to drive the pump unit 10. In the nebulizer 1, when the u-valve 17 is opened, the first channel 11 is communicated with the outside via the first branch channel 16, and when the u-valve 17 is closed, the first branch channel 16 of the first channel 11 is communicated with the outside. Communication with the outside via is canceled. When the d-valve 19 is opened, the second flow path 13 is communicated with the outside via the second branch path 18, and when the d-valve 19 is closed, the second flow path 13 is communicated with the outside through the second branch path 18. The communication with is canceled.

The control circuit 100 includes a CPU (Central Processing Unit) as a control center, a ROM (Read Only Memory) that stores programs and control data for the CPU to operate, and a RAM (Random Access Unit) that functions as a work area for the CPU. Memory), input/output interfaces, etc. are provided to maintain signal integrity with peripheral devices.

When the pump unit 10 is started, the u piezoelectric pump 12 and the d piezoelectric pump 14 compress the air drawn from the upstream side of the first flow path 11 (the left side in the figure), and Compressed air is sent to the air nozzle 20 from the middle right side). Therefore, the control circuit 100 drives the u piezoelectric pump 12 and the d piezoelectric pump 14 under predetermined driving conditions that cause the fluid to flow from the upstream side of the first flow path 11 to the downstream side of the third flow path 15. For example, the u piezoelectric pump 12 and the d piezoelectric pump 14 are each driven with a constant voltage. In particular, if there is no need to make the driving conditions different between the u piezoelectric pump 12 and the d piezoelectric pump 14, the u piezoelectric pump 12 and the d piezoelectric pump 14 are driven at the same constant voltage.

Even if the u piezoelectric pump 12 and the d piezoelectric pump 14 are driven at the same constant voltage, since the d piezoelectric pump 14 is located downstream of the u piezoelectric pump 12, more compressed air flows to the d piezoelectric pump 14. sent to. Therefore, in the normal state, the back pressure of the d piezoelectric pump 14 is higher than the back pressure of the u piezoelectric pump 12, so the current Id that drives the d piezoelectric pump 14 is lower than the current Iu that drives the u piezoelectric pump 12. Become. As a result, the current sensor 200 detects a relationship in which the current Iu of the u piezoelectric pump 12 is higher than the current Id of the d piezoelectric pump 14.

However, as shown in FIG. 2, when contamination 130 occurs in the second flow path 13, the flow of air within the flow path is obstructed and a blockage state occurs within the flow path. Note that the closed state is not limited to a state in which the flow of air in the flow path is completely obstructed, but also includes a state in which the flow of air in the flow path is obstructed to a degree that is reduced compared to the normal state. When a blockage state occurs in the flow path, the back pressure in the u piezoelectric pump 12 increases, and the current Iu that drives the u piezoelectric pump 12 becomes equal to or less than the current Id that drives the d piezoelectric pump 14. Become. When the current sensor 200 detects a relationship in which the current Iu of the u piezoelectric pump 12 is equal to or less than the current Id of the d piezoelectric pump 14, the control circuit 100 can determine that a blockage state has occurred in the flow path.

In other words, the control circuit 100 controls the flow path when the u piezoelectric pump 12 and the d piezoelectric pump 14 are driven under a predetermined drive condition that causes fluid to flow from the upstream side of the first flow path 11 to the downstream side of the third flow path 15. This utilizes the fact that when a blockage state occurs in the piezoelectric pump 12, the relationship between the current Iu of the u piezoelectric pump 12 and the current Id of the d piezoelectric pump 14 is equal or reversed. Note that the driving conditions for the u piezoelectric pump 12 and the d piezoelectric pump 14 are not limited to driving at a constant voltage, but may be other driving conditions such as driving at a constant current. Further, the driving conditions of the u piezoelectric pump 12 and the driving conditions of the d piezoelectric pump 14 do not have to be the same. For example, the amount of work of the d piezoelectric pump 14 on the downstream side is greater than the amount of work of the u piezoelectric pump 12 on the upstream side. The drive conditions for the u piezoelectric pump 12 and the drive conditions for the d piezoelectric pump 14 may be made different so that the distance increases. However, when the driving conditions are different, it is necessary to drive in a range where the current Iu of the u piezoelectric pump 12 is higher than the current Id of the d piezoelectric pump 14 in the normal state.

In addition, the control circuit 100 detects the current Iu of the u piezoelectric pump 12 and the current Id of the d piezoelectric pump 14 with the current sensor 200 to determine whether a blockage state has occurred in the flow path. If the pump 12 and the d-piezoelectric pump 14 are to be driven with constant current, a voltage sensor is provided in place of the current sensor 200, and the voltage sensor detects the voltage Vu of the u-piezoelectric pump 12 and the voltage Vd of the d-piezoelectric pump 14. Then, it is determined whether a blockage condition has occurred in the flow path. Of course, the control circuit 100 may determine the electric power Wu of the u piezoelectric pump 12 and the electric power Wd of the d piezoelectric pump 14 to determine whether a blockage state has occurred in the flow path. Further, according to the above-described method, the control circuit 100 is configured such that at least one of the u piezoelectric pump 12, the d piezoelectric pump 14, the first flow path 11, the second flow path 13, and the third flow path 15 is in a closed state. It can be determined whether or not it has occurred. Note that the method for determining whether a blockage state has occurred is not limited to the above-mentioned method. The nebulizer 1 may further be provided with various sensors, and the control circuit 100 may detect that a blockage state has occurred based on the detected value of the sensor. An example of the sensor is a flow rate sensor that detects the flow rate of the first flow path 11, the second flow path 13, and/or the third flow path 15. Another example of the sensor is a pressure sensor that detects the pressure on the suction side and the discharge side of the u piezoelectric pump 12 and/or the d piezoelectric pump 14, respectively. Still other examples of sensors are the flow rate sensor described above and the pressure sensor described above.

The control circuit 100 operates the u-valve 17, the d-valve 19, the u-piezoelectric pump 12, and the d-piezoelectric pump 14 in a specific pattern in order to avoid problems such as cracks caused by the occurrence of a blockage state in the flow path. be able to. Control according to this specific pattern may be referred to as "specific pattern control" in this specification.

FIG. 4 is a diagram showing an example of the content of specific pattern control. FIG. 4 shows the operations of the u-valve 17, the d-valve 19, the u-piezoelectric pump 12, and the d-piezoelectric pump 14.

More specifically, the specific pattern control includes three operation modes (first mode, second mode, and third mode). In the first mode, the control circuit 100 closes the u-valve 17, drives the u-piezoelectric pump 12, opens the d-valve 19, and stops driving the d-piezoelectric pump 14. In the second mode, the control circuit 100 closes the u-valve 17, drives the u-piezoelectric pump 12, opens the d-valve 19, and drives the d-piezoelectric pump 14. In the third mode, the control circuit 100 opens the u-valve 17, stops driving the u-piezoelectric pump 12, opens the d-valve 19, and stops driving the d-piezoelectric pump 14. Opening each of the u-valve 17 and the d-valve 19 connects the first channel 11, the second channel 13, and the third channel 15, including the channels, to the outside of the channel. Equivalent to. Closing each of the u-valve 17 and the d-valve 19 corresponds to cutting off the connection between the flow path and the outside of the flow path.

The control circuit 100 may execute specific pattern control when determining that a blockage state has occurred in the flow path. FIG. 5 is a flowchart of an example of a process for controlling the operation of the pump unit 10.

First, when the pump unit 10 is started, the control circuit 100 drives the u piezoelectric pump 12 and the d piezoelectric pump 14 under predetermined driving conditions (step S101). At this time, the control circuit 100 closes both the u-valve 17 and the d-valve 19. The control circuit 100 activates the pump unit 10 in response to a user operating an operation unit (not shown) in a device such as a nebulizer 1 equipped with the pump unit 10, for example.

The control circuit 100 causes the current sensor 200 to detect the current Iu of the u piezoelectric pump 12 and the current Id of the d piezoelectric pump 14 while driving the u piezoelectric pump 12 and the d piezoelectric pump 14 under the above-mentioned predetermined driving conditions ( Step S102). The current Iu of the u piezoelectric pump 12 and the current Id of the d piezoelectric pump 14 detected by the current sensor 200 are input to the control circuit 100.

The control circuit 100 determines whether the detected current Iu of the u piezoelectric pump 12 is greater than or equal to the current Id of the d piezoelectric pump 14 (step S103). When the detected current Iu of the u piezoelectric pump 12 is higher than the current Id of the d piezoelectric pump 14, the control circuit 100 can determine that the operating state of the pump unit 10 is the normal state. On the other hand, if the detected current Iu of the u piezoelectric pump 12 is equal to or less than the current Id of the d piezoelectric pump 14, the control circuit 100 can determine that the operating state of the pump unit 10 is a closed state.

If it is determined that the detected current Iu of the u piezoelectric pump 12 is higher than the current Id of the d piezoelectric pump 14 (NO in step S103), the control circuit 100 determines that the operating state of the pump unit 10 is the normal state, and performs step S107. Proceed control to. As a result, the control circuit 100 continues to drive the u piezoelectric pump 12 and d piezoelectric pump 14 under the predetermined driving conditions, and the current The sensor 200 continues to detect the current Iu of the u piezoelectric pump 12 and the current Id of the d piezoelectric pump 14.

On the other hand, if it is determined that the detected current Iu of the u piezoelectric pump 12 is less than or equal to the current Id of the d piezoelectric pump 14 (YES in step S103), the control circuit 100 determines that the operating state of the pump unit 10 is in a closed state, Specific pattern control is executed (steps S104 to S106). That is, the control circuit 100 executes control in the first mode (step S104), executes control in the second mode (step S105), and executes control in the third mode (step S106). . Thereafter, control proceeds to step S107.

The control circuit 100 determines whether an input to stop driving the pump unit 10 (u piezoelectric pump 12 and d piezoelectric pump 14) has been received (step S107). The input is realized, for example, by the user operating an operation unit (not shown).

If the input to stop the driving of the u piezoelectric pump 12 and the d piezoelectric pump 14 is not received (NO in step S107), the control circuit 100 returns control to step S102.

On the other hand, if the above input to stop is received (YES in step S107), the control circuit 100 stops driving the u piezoelectric pump 12 and the d piezoelectric pump 14, and ends the process of FIG. 5.

(Modified examples, etc.)
As described above, the control circuit 100 executes specific pattern control including the first mode, second mode, and third mode. The first mode corresponds to a first stage of suction for evacuation of contaminants via the first branch 16 and/or the second branch 18. The second mode corresponds to a second stage of suction for said evacuation of contaminants. The third mode corresponds to a substantial part of the above-mentioned discharge of contamination, and also functions as a cooling of the first flow path 11, the second flow path 13, and the third flow path 15. Even if contamination 130 occurs in the first flow path 11, the second flow path 13, and/or the third flow path 15 by executing the specific pattern control, the contamination 130 will be removed from the first branch. It is discharged from channel 16 and/or second branch channel 18 . This prevents the occurrence of a blockage state, and even if a blockage state occurs, the blockage state is resolved. Thereby, in the pump unit 10, occurrence of problems due to the blocked state can be avoided.

The length of each of the first mode, second mode, and third mode may be set as appropriate depending on the situation in which the pump unit 10 is applied. The length of the second mode may be set longer than the length of each of the first mode and the third mode. For example, the ratio of first mode time: second mode time: third mode time may be set to about 1:8:1.

The control circuit 100 performs the specific pattern control as control for transporting the fluid from the first flow path 11 to the third flow path 15 via the second flow path 13 (hereinafter also referred to as "fluid transport control"). It may be executed at a timing related to the execution of . "Executed at a timing related to the execution of the control for transporting fluid" means that a specific pattern is executed before the control for fluid transport, during the control for fluid transport, and/or after the control for fluid transport. means to exercise control.

The control circuit 100 may perform specific pattern control before fluid transport control. More specifically, upon receiving an instruction to start the operation of the nebulizer 1, the control circuit 100 may execute specific pattern control and then execute fluid transport control. Thereby, the specific pattern control is executed immediately before the user uses the nebulizer 1. Therefore, occurrence of defects such as cracks when a user uses the nebulizer 1 can be more reliably avoided.

The control circuit 100 may execute specific pattern control during fluid transport control. More specifically, when the control circuit 100 receives an instruction to start the operation of the nebulizer 1, it starts the fluid transport control, and during the fluid transport control (for example, the fluid transport control The specific pattern control may be executed every time a certain period of time has elapsed since the start of the process. This more reliably prevents problems such as cracks from occurring while the user is using the nebulizer 1.

The control circuit 100 may perform specific pattern control after fluid transport control. More specifically, when the control circuit 100 receives an instruction to start the operation of the nebulizer 1, it starts fluid transport control, and executes specific pattern control in response to the completion of the fluid transport control. You may. Thereby, even if contamination occurs in one fluid transport control, problems such as cracks due to the contamination can be more reliably avoided in the next fluid transport control.

The control circuit 100 may perform specific pattern control in response to occurrence of blockage in the flow path of the pump unit 10.

In particular, the control circuit 100 may detect the presence or absence of blockage in the flow path based on the current Iu of the u piezoelectric pump 12 and the current Id of the d piezoelectric pump 14, as explained in FIG. In detecting the presence or absence of occlusion, the control circuit 100 uses other types of values that depend on the amount of electricity of each pump, such as a voltage value or a power value, instead of or in addition to the current value. You may. In this disclosure, current, voltage, or electric power is collectively referred to as an amount of electricity.

In the pump unit 10, the first branch passage 16 provided with the u-valve 17 and the second branch passage 18 provided with the d-valve 19 are respectively connected to a fluid transport path (the first passage 11, the second passage This is a flow path branching off from the path 13 and the third flow path 15). The fluid transport path is an example of a main path. Further, each of the first branch passage 16 and the second branch passage 18 is an example of a first sub-channel and a second sub-channel, respectively. In order to more reliably discharge contamination 130, the cross-sectional area of each of the first branch passage 16 and second branch passage 18 is set to may be larger than the cross-sectional area of each tube.

When driving the piezoelectric pump 12 and the d-piezoelectric pump 14, the control circuit 100 may drive the piezoelectric pump 12 and the d-piezoelectric pump 14 so that the amount of electricity of the d-piezoelectric pump 14 is larger than that of the u-piezoelectric pump 12. . As a result, the d-piezoelectric pump 14 can take on a larger amount of work than the u-piezoelectric pump 12, and the lifespans of the piezoelectric pump 12 and d-piezoelectric pump 14 can be equalized.

The embodiments disclosed this time should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is indicated by the claims rather than the above description, and it is intended that equivalent meanings and all changes within the scope of the claims are included.

Reference Signs List 1 nebulizer, 10 pump unit, 11 first channel, 12, 14 piezoelectric pump, 13 second channel, 15 third channel, 16 first branch channel, 17, 19 valve, 18 second branch channel, 20 air nozzle , 30 atomization nozzle, 40 chemical tank, 42 piping, 50 mouthpiece, 100 control circuit, 200 current sensor.

Claims (6)

a first flow path;
a first piezoelectric pump connected to one end of the first flow path;
a second piezoelectric pump;
a second flow path having one end connected to the first piezoelectric pump and the other end connected to the second piezoelectric pump;
a third flow path having one end connected to the second piezoelectric pump;
a first branch path branched from the first flow path;
a first valve that is provided in the first branch path and switches between communication and non-communication between the first flow path and the outside;
a second branch path branched from the second flow path;
a second valve that is provided in the second branch path and switches between communication and non-communication between the second flow path and the outside;
a control unit that controls driving of the first piezoelectric pump and the second piezoelectric pump, and opening and closing of the first valve and the second valve;
The control unit includes:
a first mode in which the first valve is closed, the first piezoelectric pump is driven, the second valve is opened, and the second piezoelectric pump is stopped;
a second mode, which is implemented after the first mode, closes the first valve, drives the first piezoelectric pump, closes the second valve, and further drives the second piezoelectric pump;
A third mode is implemented after the second mode, and opens the first valve, stops driving the first piezoelectric pump, opens the second valve, and further stops driving the second piezoelectric pump. A fluid control device that performs specific pattern control including; The fluid control device according to claim 1, wherein a period during which the second mode is executed is longer than each of a period during which the first mode is executed and a period during which the third mode is executed. The control unit controls the first flow path, the first piezoelectric pump, The fluid control device according to claim 1 or 2, wherein the fluid control device specifies that a blockage has occurred in at least one of the second flow path, the second piezoelectric pump, and the third flow path. A cross-sectional area of each tube of the first branch path and the second branch path is larger than a cross-sectional area of each tube of the first flow path, the second flow path, and the third flow path. The fluid control device according to any one of claims 1 to 3. Claims 1 to 4, wherein the control unit drives the first piezoelectric pump and the second piezoelectric pump such that the quantity of electricity of the second piezoelectric pump is greater than the quantity of electricity of the first piezoelectric pump. The fluid control device according to any one of the above. A method for controlling a fluid control device, the method comprising:
The fluid control device includes a first flow path, a first piezoelectric pump connected to one end of the first flow path, a second piezoelectric pump, and one end connected to the first piezoelectric pump and the other end connected to the first piezoelectric pump. a second flow path connected to two piezoelectric pumps, a third flow path connected at one end to the second piezoelectric pump, a first branch path branched from the first flow path, and provided in the first branch path. a first valve that switches communication/non-communication between the first flow path and the outside; a second branch path branched from the second flow path; a second valve that switches between communication and non-communication between the road and the outside;
implementing a first mode in which the first valve is closed, the first piezoelectric pump is driven, the second valve is opened, and the second piezoelectric pump is stopped;
After the first mode, implementing a second mode of closing the first valve, driving the first piezoelectric pump, closing the second valve, and driving the second piezoelectric pump;
After the second mode, a third mode opens the first valve, stops driving the first piezoelectric pump, opens the second valve, and further stops driving the second piezoelectric pump; 1. A method for controlling a fluid control device, comprising: performing specific pattern control including:

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