nebulizer

Abstract

The present application provides an atomizer, the atomizer is provided with: a first piezoelectric pump, which discharges gas from a discharge port; a first flow path, which is a flow path having a first end connected to the discharge port of the first piezoelectric pump and a second end, and a connection point provided between the first end and the second end; a liquid storage portion for storing liquid; and a second flow path having a first end connected to the liquid storage portion and a second end connected to the connection point.

Description

[0001] This application is a divisional application of application number 201980077512.9, filed on November 28, 2019, entitled "Atomizer". Technical Field

[0002] This invention relates to an atomizer that mixes liquids and gases and atomizes them. Background Technology

[0003] Previously, atomizers that mix and atomize liquid and gas have been disclosed (for example, see Patent Document 1).

[0004] Patent Document 1 describes an atomizer comprising a jet cylinder for jetting air as a gas and a liquid storage container for storing liquid. The jet cylinder is connected to the liquid storage container, allowing air to be jetted manually by the user. A narrow section with a reduced cross-sectional area is provided at the connection between the jet cylinder and the liquid storage container. When air is jetted from the jet cylinder, a negative pressure is generated as the air passes through the narrow section, producing a Venturi effect. Due to the Venturi effect, liquid in the liquid storage container is attracted, mixed with the air, and atomized. The atomized liquid is discharged from the outlet provided in the atomizer.

[0005] Patent Document 1: Japanese Patent Application Publication No. 2008-247405

[0006] The atomizer in Patent Document 1 needs to simultaneously optimize the liquid-gas mixing ratio for liquid atomization and the gas flow rate for the Venturi effect in a narrow section that serves as the liquid-gas mixing point. To optimize these two factors, the design range for the internal shape and cross-sectional area of ​​this narrow section is very narrow. In other words, the atomizer in Patent Document 1 presents a very high level of design difficulty in simultaneously optimizing the liquid-gas mixing ratio for liquid atomization and the gas flow rate for the Venturi effect. Summary of the Invention

[0007] Therefore, the object of the present invention is to solve the above-mentioned problems and provide an atomizer with lower design difficulty than in the past for simultaneously optimizing the liquid-gas mixing ratio for liquid atomization and optimizing the gas flow rate for the Venturi effect.

[0008] To achieve the above objectives, the atomizer of the present invention comprises: a first piezoelectric pump for discharging gas from an outlet; a first flow path having a second end and a first end connected to the outlet of the first piezoelectric pump, and a connection point provided between the first end and the second end; a liquid storage section for storing liquid; and a second flow path having a first end connected to the liquid storage section and a second end connected to the connection point.

[0009] The atomizer according to the present invention reduces the difficulty of designing both the liquid-gas mixing ratio for liquid atomization and the gas flow rate for the Venturi effect compared to the past, and enables simpler atomization control. Attached Figure Description

[0010] Figure 1 This is a perspective view of the atomizer in Implementation Method 1.

[0011] Figure 2 This is a perspective view showing the internal structure of the atomizer in Embodiment 1.

[0012] Figure 3 This is an enlarged view of the connection point in Implementation Method 1.

[0013] Figure 4 This is a diagram showing the internal structure of the tank in Embodiment 1.

[0014] Figure 5 This is an enlarged view of the periphery of the flow path resistance element in Implementation Method 1.

[0015] Figure 6 This is a schematic diagram showing the atomizer in variation 1 of embodiment 1.

[0016] Figure 7 This is a schematic diagram showing the atomizer in variation 2 of embodiment 1.

[0017] Figure 8 This is a diagram showing a modified example of the flow path resistance element in Embodiment 1.

[0018] Figure 9 This is a diagram showing other variations of the flow path resistance element in Embodiment 1.

[0019] Figure 10 This is a perspective view showing the internal structure of the atomizer in Embodiment 2.

[0020] Figure 11 Enlarged view of the connection point in Implementation Method 2.

[0021] Figure 12 This is a graph showing the pulsation-related results when operating an atomizer using a piezoelectric pump (Example) and an atomizer using a motor pump (Comparative Example).

[0022] Figure 13 It is a graph showing the relationship between gas flow rate and atomization amount.

[0023] Figure 14This is a graph showing the atomization output of the atomizers in the comparative examples.

[0024] Figure 15 This is a graph showing the atomization amount of the atomizer in the embodiment.

[0025] Figure 16 This is a graph comparing the total flow rate of the atomizers in the comparative and exemplary cases.

[0026] Figure 17 It is a graph showing the relationship between flow rate and particle size.

[0027] Figure 18 This is a graph showing the particle size-based ratio of the liquids atomized by the various atomizers in the comparative examples and embodiments. Detailed Implementation

[0028] According to a first aspect of the present invention, an atomizer is provided, comprising: a first piezoelectric pump for discharging gas from an outlet; a first flow path having a first end and a second end connected to the outlet of the first piezoelectric pump, and a connection point provided between the first end and the second end; a liquid storage section for storing liquid; and a second flow path having a first end connected to the liquid storage section and a second end connected to the connection point.

[0029] Based on this configuration, by discharging gas through a piezoelectric pump, the flow rate of the discharged gas can be set by pre-setting output conditions such as the drive frequency. Therefore, compared to other types of pumps, the design difficulty for optimizing both the liquid-gas mixing ratio for liquid atomization and the gas flow rate for the Venturi effect is reduced, allowing for simple atomization control.

[0030] According to a second aspect of the present invention, the atomizer described in the first aspect is provided, further comprising a branch flow path having a first end connected between the first end and the connection point in the first flow path, and a second end connected to the liquid storage portion. With this configuration, a first piezoelectric pump can be used as the driving source for both the gas and liquid delivery, enabling a reduction in manufacturing costs and miniaturization of the atomizer.

[0031] According to a third aspect of the present invention, an atomizer as described in the second aspect is provided, wherein a backflow prevention mechanism for preventing liquid backflow is provided in the aforementioned branch flow path. With this configuration, it is possible to prevent liquid in the liquid accumulation section from erroneously flowing back into the branch flow path, thereby improving the reliability of the atomizer.

[0032] According to a fourth aspect of the present invention, the atomizer described in the first aspect is provided, further comprising: a second piezoelectric pump that discharges gas from an outlet; and a third flow path having a first end connected to the outlet of the second piezoelectric pump and a second end connected to the liquid storage section. With this configuration, by using a piezoelectric pump not only as a gas driving source but also as a liquid driving source, setting the flow rate of the liquid delivered to the connection point becomes easier, and atomization control can be performed more simply.

[0033] According to a fifth aspect of the present invention, an atomizer as described in the fourth aspect is provided, further comprising a bypass flow path connecting the position between the first end and the connection point on the first flow path and the third flow path. With this configuration, by providing the bypass flow path, gas exchange can be performed between the first and third flow paths, and the gas flow rate of each flow path can be adjusted.

[0034] According to a sixth aspect of the present invention, an atomizer as described in the fifth aspect is provided, wherein a flow path resistance member is provided in the third flow path, closer to the second end than at the location where the bypass flow path is connected. With this configuration, by providing a flow path resistance member in the third flow path, the flow of gas from the third flow path to the first flow path via the bypass flow path can be promoted, and the flow rate of the gas flowing in the first flow path can be increased. Therefore, atomization at the connection point can be promoted.

[0035] According to a seventh aspect of the present invention, an atomizer described in any one of the fourth to sixth aspects is provided, wherein a backflow prevention mechanism for preventing liquid backflow is provided in the third flow path. With this configuration, it is possible to prevent liquid in the liquid accumulation section from erroneously flowing back into the third flow path and reaching the second piezoelectric pump. This improves the reliability of the atomizer.

[0036] According to an eighth aspect of the present invention, an atomizer as described in any one of the first to seventh aspects is provided, wherein the first flow path extends in a straight line from the first end to the second end. With this configuration, the flow rate of the gas discharged from the first piezoelectric pump can be maintained as much as possible, and atomization can be performed more reliably.

[0037] According to a ninth aspect of the present invention, an atomizer described in any one of the first to eighth aspects is provided, further comprising a housing that at least accommodates the first piezoelectric pump, the first flow path, the second flow path, and the liquid storage portion. This configuration improves user convenience in terms of portability, etc.

[0038] According to a tenth aspect of the present invention, an atomizer as described in the ninth aspect is provided, wherein the liquid storage section is a container housed within the aforementioned casing. With this configuration, a predetermined amount of liquid can be ensured.

[0039] According to the eleventh aspect of the present invention, an atomizer described in any one of the first to tenth aspects is provided, wherein the second flow path is connected to the first flow path and intersects the first flow path, its front end is bent within the first flow path, and extends concentrically toward the outlet of the first flow path. With this configuration, atomization can be achieved using a simple nozzle structure.

[0040] (Implementation Method 1)

[0041] Hereinafter, based on the accompanying drawings, a detailed description of Embodiment 1 of the present invention will be provided.

[0042] Figure 1 This is a perspective view of the atomizer 2 according to Embodiment 1 of the present invention.

[0043] Atomizer 2 is a device that mixes and atomizes liquid and gas. Figure 1 The nebulizer 2 shown includes a housing 4, a switch 6, and an outlet 8. The nebulizer 2 is used, for example, as a medical nebulizer. Liquids may include, for example, saline solution, organic solvents (ethanol, etc.), or medications (steroids, β2-receptor agonists, etc.). Gases may include, for example, air. When the user presses the switch 6, the atomized liquid is discharged from the outlet 8.

[0044] The housing 4 is the component that forms the outline of the atomizer 2. A switch 6 is exposed on the upper surface of the housing 4. The switch 6 is a switching component that electrically switches the operation of the atomizer 2 on / off.

[0045] A discharge port 8 is formed on the side of the housing 4. The discharge port 8 is an opening for discharging the atomized liquid.

[0046] The housing 4 includes a first housing portion 4A and a second housing portion 4B. Figure 1 In the middle, the first housing part 4A and the second housing part 4B are fastened together with screws.

[0047] The state after removing the first housing part 4A from the atomizer 2 is as follows: Figure 2 As shown. Figure 2 As shown, the atomizer 2 includes a first piezoelectric pump 10, a second piezoelectric pump 12, a first flow path 14, a second flow path 16, a third flow path 18, a bypass flow path 20, a canister 21, and a control board 22. These components are housed inside the housing 4.

[0048] The first piezoelectric pump 10 and the second piezoelectric pump 12 are piezoelectric pumps (also referred to as "miniature blowers," "miniature pumps," etc.) that utilize piezoelectric elements. Specifically, they have a structure in which a piezoelectric element (not shown) is bonded to a metal plate (not shown). Gas is transported by supplying alternating current to the piezoelectric element and the metal plate, causing bending deformation in a single piezoelectric mode. A diaphragm (not shown) that functions as a valve, restricting gas flow to one direction, is built into such a piezoelectric pump.

[0049] The first piezoelectric pump 10 has a discharge port 10A. Gas is discharged from the discharge port 10A in the A1 direction. Similarly, the second piezoelectric pump 12 has a discharge port 12A, and gas is discharged from the discharge port 12A in the B1 direction. In Embodiment 1, the A1 direction and the B1 direction are horizontal directions that are parallel to each other.

[0050] A first flow path 14 is connected to the first piezoelectric pump 10. The first flow path 14 is a flow path for gas discharged from the first piezoelectric pump 10. The first flow path 14 has a first end 14A as an inlet and a second end 14B as an outlet. The first end 14A is connected to the outlet 10A of the first piezoelectric pump 10, and the second end 14B faces the outlet 8. In Embodiment 1, the first flow path 14 extends in a straight line from the first end 14A to the second end 14B. The A2 direction of the extension of the first flow path 14 and the A3 direction of the gas discharged from the outlet 8 are both aligned with the A1 direction. According to this configuration, the gas discharged from the outlet 10A of the first piezoelectric pump 10 travels in a straight line and is discharged from the outlet 8 via the second end 14B.

[0051] Near the second end 14B, a second flow path 16 is connected to the first flow path 14. The second flow path 16 extends to supply liquid from the tank 21 to the first flow path 14. The second flow path 16 has a first end 16A as an inlet and a second end 16B as an outlet. Figure 3 The first end 16A is connected to the tank 21, and the second end 16B is connected to the first flow path 14. The connection point 24 is where the second flow path 16 connects to the first flow path 14. The connection point 24 corresponds to the mixing point of the gas and liquid mixture.

[0052] Enlarged view of connection point 24 is shown below Figure 3 As shown. Figure 3As shown, the second flow path 16 intersects the first flow path 14 at approximately orthogonal angles. The front end 25 of the second flow path 16 is bent approximately 90 degrees inside the first flow path 14 to be concentric with it. The second end 16B of the second flow path 16 faces the second end 14B of the first flow path 14. With this nozzle shape (so-called ejector), the liquid supplied from the second flow path 16 flows through the center of the first flow path 14 (arrow D1), and the gas discharged from the first piezoelectric pump 10 flows around it (arrow A2). Thus, by setting the velocity and flow rate of the gas discharged from the first piezoelectric pump 10 to a desired range based on the flow rate of the liquid supplied from the second flow path 16, atomization of the connection point 24 can be achieved.

[0053] Return to Figure 2 A third flow path 18 is connected to the second piezoelectric pump 12. The third flow path 18 is a flow path that leads the gas discharged from the second piezoelectric pump 12 to the tank 21. The third flow path 18 has a first end 18A as an inlet and a second end 18B as an outlet. The first end 18A is connected to the outlet 12A of the second piezoelectric pump 12, and the second end 18B is disposed in the internal space of the tank 21 where no liquid is filled. The third flow path 18 connects to the internal space of the tank 21 from the outlet 12A of the second piezoelectric pump 12. The third flow path 18 extends in the B2 direction, which is the same direction as the B1 direction, and then bends obliquely upwards and extends in the B3 direction.

[0054] Tank 21 is the liquid storage section for storing liquid. (See also...) Figure 4 The internal structure of tank 21 will be described. Figure 4 This is a diagram showing tank 21 and its surrounding area.

[0055] like Figure 4 As shown, tank 21 is filled with liquid up to liquid level H. The first end 16A of the second flow path 16 is located below liquid level H, and the second end 18B of the third flow path 18 is located above liquid level H.

[0056] According to this configuration, the gas discharged from the third flow path 18 is discharged into the interior of the tank 21 from the second end 18B. As a result, the internal pressure of the tank 21 increases, exerting a force on the liquid surface H. The liquid in the tank 21 is pushed from the first end 16A of the second flow path 16 toward the connection point 24, causing it to rise in the second flow path 16 (arrow D).

[0057] Thus, the second end 18B of the third flow path 18 is positioned at the point where the gas discharged from the third flow path 18 pushes the liquid out of the tank 21 toward the first end 16A of the second flow path 16.

[0058] Return to Figure 2A bypass flow path 20 is provided between the first flow path 14 and the third flow path 18. The bypass flow path 20 is a flow path that enables gas exchange between the first flow path 14 and the third flow path 18. The bypass flow path 20 connects to the first flow path 14 at connection point 26 and to the third flow path 18 at connection point 28. Both connection points 26 and 28 are located upstream of the aforementioned connection point 24. In particular, connection point 26 is located between the first end 14A of the first flow path 14 and connection point 24.

[0059] In Embodiment 1, the bypass flow path 20 serves to guide the gas from the third flow path 18 to the first flow path 14 (arrow C). That is, the inlet (first end) of the bypass flow path 20 is connection point 28, and the outlet (second end) of the bypass flow path 20 is connection point 26. To form such a flow, a flow path resistance element 30 is provided in the third flow path 18.

[0060] An enlarged view of the periphery of the flow path resistance component 30 is shown below. Figure 5 As shown. Figure 5 As shown, the flow resistance member 30 in Embodiment 1 is a component that protrudes partially into the interior of the third flow path 18, functioning as a valve. Because the flow resistance member 30 protrudes into the interior of the third flow path 18, the cross-sectional area of ​​the third flow path 18 is locally narrowed, forming a narrow section 60, which functions as a flow resistance member. Alternatively, the flow resistance member 30 can be prevented from penetrating the interior of the third flow path 18, and the narrow section 60 can be formed in the third flow path 18 by applying pressure from the outside to deform it. By providing the narrow section 60, the flow resistance of the third flow path 18 can be increased, thereby promoting flow to the bypass flow path 20 and the first flow path 14. The form of the flow resistance member 30 is not limited to a valve; it can be any form, such as a throttle, that functions as a flow resistance member. Furthermore, if it can be deformed to narrow the third flow path 18, a simple cylindrical body can be used as the flow resistance member without a valve.

[0061] Through Figure 2 A flow path resistance element 30 is provided downstream of the connection point 28, which can promote the flow of gas from the third flow path 18 to the first flow path 14 via the bypass flow path 20, and increase the flow rate of the gas flowing in the first flow path 14. As a result, atomization at the connection point 24 can be promoted.

[0062] The remaining gas in the third flow path 18 flows toward the tank 21.

[0063] The control board 22 is a component used to drive the piezoelectric pump. In Embodiment 1, the control board 22 drives the second piezoelectric pump 12. On the other hand, other control boards (not shown) are assigned to the first piezoelectric pump 10.

[0064] The control board 22 is electrically connected to both the switch 6 and the second piezoelectric pump 12. When the user presses the switch 6, a signal flows from the switch 6 to the control board 22. Upon receiving this signal, the control board 22 applies a drive voltage to the second piezoelectric pump 12, driving the second piezoelectric pump 12. Similarly, a drive voltage is applied to the first piezoelectric pump 10 from the control board (not shown), driving the first piezoelectric pump 10. Pressing the switch 6 simultaneously drives both the first piezoelectric pump 10 and the second piezoelectric pump 12. The drive voltages for the piezoelectric pumps 10 and 12 are, for example, set to 20kHz to 40kHz. In Embodiment 1, the first piezoelectric pump 10 and the second piezoelectric pump 12 use piezoelectric pumps of the same specifications and output.

[0065] like Figure 1 As shown, the housing 4 of Embodiment 1 houses all the components of the atomizer 2 described above, but some components such as the switch 6 are exposed outside the housing 4.

[0066] The operation of the atomizer 2 with the above-described configuration will be explained. First, the user presses the switch 6. This drives the first piezoelectric pump 10 and the second piezoelectric pump 12. Gas is discharged from the first piezoelectric pump 10 in the direction A1, while gas is discharged from the second piezoelectric pump 12 in the direction B1. In Embodiment 1, the outputs of the first piezoelectric pump 10 and the second piezoelectric pump 12 are the same, and the flow rate and velocity of the gas discharged from the outlets 10A and 12A of each piezoelectric pump 10 and 12 are the same.

[0067] As described above, a flow resistance element 30 is provided in the second flow path 18, so gas flows from the third flow path 18 to the first flow path 14 via the bypass flow path 20 (arrow C). As a result, the flow rate of the gas flowing in the first flow path 14 increases, while the flow rate of the gas flowing in the third flow path 18 decreases.

[0068] The gas flowing in the first flow path 14 is supplied to the connection point 24 (arrow A2). The gas discharged from the first piezoelectric pump 10 travels in a straight line within the first flow path 14 and reaches the connection point 24. Because it travels in a straight line, the flow rate of the gas discharged from the first piezoelectric pump 10 can be maintained as much as possible without slowing down.

[0069] On the other hand, the gas flowing in the third flow path 18 is delivered to tank 21 (arrows B2, B3). By supplying gas to tank 21, the pressure of the liquid in tank 21 is reduced, and the liquid in tank 21 is delivered to connection point 24 (arrow D) via the first end 16A of the second flow path 16.

[0070] Subsequently, the gas and liquid are mixed at connection point 24. (As...) Figure 3As shown, liquid flows from the front end 25 of the second flow path 16 to the second end 14B of the first flow path 14 (arrow D1), while gas flows around it (arrow A2). The flow rates and velocities of the gas and liquid delivered to the connection point 24 are preset to values ​​that satisfy the atomization conditions. Therefore, the liquid can be reliably atomized at the connection point 24. The atomized liquid is discharged from the outlet 8 through the second end 14B of the first flow path 14.

[0071] As described above, the atomizer 2 according to Embodiment 1 uses piezoelectric pumps 10 and 12 as drive sources to achieve atomization. When using piezoelectric pumps 10 and 12, the flow rate and velocity of the gas supplied to the connection point 24 can be adjusted by pre-setting output conditions such as the drive frequency. Therefore, by setting the flow rate and velocity of the gas supplied to the connection point 24 to an appropriate range corresponding to the flow rate of the liquid, atomization can be achieved with high precision. Thus, compared to conventional atomization using a compressor-type pump utilizing the Venturi effect, the design difficulty for simultaneously optimizing the liquid-gas mixing ratio for liquid atomization and optimizing the gas flow rate for the Venturi effect is lower. This makes atomization easy to achieve and easy to control. Furthermore, by changing the gas flow rate and velocity within the range where atomization is possible, the particle size of the atomized liquid can be adjusted. Additionally, the piezoelectric pumps 10 and 12 cause the piezoelectric element to vibrate at high speed to expel gas, thus suppressing pulsation and providing excellent quietness. Furthermore, by maintaining a constant drive cycle for the piezoelectric pumps 10 and 12, a constant amount of atomized liquid can be continuously discharged. Additionally, the piezoelectric pumps 10 and 12 can be smaller in size compared to compressor-type pumps, enabling miniaturization of the atomizer 2.

[0072] As described above, the atomizer 2 of Embodiment 1 includes a first piezoelectric pump 10, a first flow path 14, a canister 21, and a second flow path 16. The first piezoelectric pump 10 is a pump that discharges gas from the outlet 10A. The first flow path 14 is a flow path having a first end 14A connected to the outlet 10A of the first piezoelectric pump 10 and a second end 14B, and a connection point 24 is provided between the first end 14A and the second end 14B. The canister 21 is a liquid storage section for storing liquid. The second flow path 16 is a flow path having a first end 16A connected to the canister 21 and a second end 16B connected to the connection point 24.

[0073] In this way, by using the first piezoelectric pump 10 as the driving source to discharge gas, the flow rate of the discharged gas can be set by pre-setting output conditions such as the driving frequency. Therefore, compared with other types of pumps, it is easier to design to optimize both the liquid-gas mixing ratio for liquid atomization and the gas flow rate for the Venturi effect, and atomization control can be performed more easily.

[0074] Furthermore, the atomizer 2 in Embodiment 1 also includes a second piezoelectric pump 12 and a third flow path 18. The second piezoelectric pump 12 is a pump that discharges gas from the outlet 12A. The third flow path 18 is a flow path having a first end 18A connected to the outlet 12A of the second piezoelectric pump 12 and a second end 18B connected to the canister 21. With this configuration, by using the piezoelectric pump not only as a driving source for gas but also as a driving source for liquid, it becomes easier to set the flow rate of the liquid delivered to the connection point 24, and atomization control can be performed more easily.

[0075] Furthermore, the atomizer 2 in Embodiment 1 also includes a bypass flow path 20 that connects the position between the first end 14A and the connection point 24 on the first flow path 14 to the third flow path 18. By providing the bypass flow path 20, gas exchange can be performed between the first flow path 14 and the third flow path 18, and the flow rate between each flow path 14 and 18 can be adjusted.

[0076] Furthermore, in Embodiment 1, the atomizer 2 has a flow path resistance element 30 in the third flow path 18, located further downstream of the second end 18B than at the connection point 28, i.e., at the connection point 20. By providing the flow path resistance element 30, the flow of gas from the third flow path 18 to the first flow path 14 in the bypass flow path 20 can be promoted, thereby increasing the flow rate of the gas flowing in the first flow path 14. As a result, atomization at the connection point 24 can be promoted.

[0077] Furthermore, according to the atomizer 2 of Embodiment 1, the first flow path 14 extends in a straight line from the first end 14A to the second end 14B. Thus, the gas discharged from the first piezoelectric pump 10 advances in a straight line in the first flow path 14 and is discharged from the second end 14B. Maintaining the flow rate of the gas discharged from the first piezoelectric pump 10 as much as possible promotes atomization at the connection point 24.

[0078] Furthermore, the atomizer 2 in Embodiment 1 also includes a housing 4. By providing such a housing 4, user convenience can be improved in terms of portability, etc.

[0079] Furthermore, according to the atomizer 2 of Embodiment 1, a container 21 housed in the housing 4 is used as a liquid storage section for storing liquid. By using the container 21, a specified amount of liquid can be ensured.

[0080] Furthermore, in the atomizer 2 according to Embodiment 1, the second flow path 16 is connected to the first flow path 14 and intersects with it. Its front end 25 is bent within the first flow path 14 and extends concentrically toward the second end 14B of the first flow path 14. With this configuration, atomization can be achieved using a simple nozzle structure.

[0081] The present invention has been described above using the above-described embodiment 1, but the present invention is not limited to embodiment 1. For example, although the case of providing a bypass flow path 20 was described in embodiment 1, it is not limited to this case, and it is also possible to not provide a bypass flow path 20. That is, the first flow path 14 corresponding to the first piezoelectric pump 10 and the third flow path 18 corresponding to the second piezoelectric pump 12 can be made independent. In this case, the flow rate and velocity of the "gas" supplied to the connection point 24 can be controlled by the output of the first piezoelectric pump 10, and the flow rate and velocity of the "liquid" supplied to the connection point 24 can be controlled by the output of the second piezoelectric pump 12. That is, the flow rate and velocity of the gas and liquid can be controlled independently, and atomization control can be easily achieved.

[0082] Furthermore, although the use of two piezoelectric pumps 10 and 12 was described in Embodiment 1, it is not limited to this case, and only one piezoelectric pump may be used. For example, the second piezoelectric pump 12 may be omitted in the atomizer 2 of Embodiment 1, and only the first piezoelectric pump 10 may be provided. In this case, in order to direct the liquid in the tank 21 to the connection point 24, a branch flow path may be provided, branching from the first flow path 14 to the tank 21. Examples of branch flow paths are as follows: Figure 6 As shown.

[0083] Figure 6 This is a schematic diagram of a modified example where the piezoelectric pump is only the first piezoelectric pump 10, and a branch flow path 32 is provided. For example... Figure 6 As shown, a branch flow path 32 is provided that connects the canister 21 to a position between the connection point 24 and the first end 14A in the first flow path 14 (i.e., upstream of the connection point 24). The branch flow path 32 has a first end 32A as an inlet and a second end 32B as an outlet. The first end 32A is connected to the first flow path 14 upstream of the connection point 24, and the second end 32B is connected to the canister 21. The second end 32B of the branch flow path 32 is positioned at the point where the gas discharged from the branch flow path 32 pushes the liquid out of the canister 21 towards the first end 16A of the second flow path 16. By providing such a branch flow path 32, the first piezoelectric pump 10 can be used as the driving source for the flow of both gas and liquid, thereby reducing the manufacturing cost and miniaturizing the atomizer 2.

[0084] exist Figure 6 In the illustrated configuration, a backflow prevention mechanism 34 is also provided in the branch flow path 32 to prevent liquid backflow. By providing the backflow prevention mechanism 34 in the branch flow path 32, it is possible to prevent the liquid in the tank 21 from erroneously flowing back in the branch flow path 32, thereby improving the reliability of the atomizer 2. The backflow prevention mechanism 34 can be any mechanism such as a filter that allows gas to pass through but not liquid.

[0085] Similarly, it can also be done in Figure 2 The third flow path 18 shown is equipped with a backflow prevention mechanism (not shown) to prevent liquid backflow. By providing a backflow prevention mechanism in the third flow path 18, it is possible to prevent the liquid in the tank 21 from mistakenly flowing back into the third flow path 18 and reaching the second piezoelectric pump 12. This improves the reliability of the atomizer 2. Furthermore, although in Embodiment 1, the second end 18B of the third flow path 18 is positioned above the liquid surface H, if, for example, a backflow prevention mechanism is provided at the first end 18A of the third flow path 18, normal operation can still be performed even if the vertical relationship between the second end 18B and the liquid surface H is reversed. In this case, a more flexible design is possible.

[0086] about Figure 6 The method shown can further omit the branch flow path 32 and the backflow prevention mechanism 34. Examples are as follows: Figure 7 As shown. In Figure 7 In the example shown, without the branch flow path 32, the first piezoelectric pump 10 does not have the function of discharging liquid from tank 21. The liquid in tank 21 is supplied to connection point 24 by a unit other than the piezoelectric pump. For example, the unit other than the piezoelectric pump may introduce liquid via the Venturi effect, or supply liquid by gravity by positioning the first end 16A of the second flow path 16 above the second end 16B. Even with such a configuration, it is possible to mix and atomize the gas discharged from the first piezoelectric pump 10 with the liquid in tank 21 at connection point 24.

[0087] In addition, although the liquid storage part of the liquid storage unit is described as tank 21 in Embodiment 1, it is not limited to such a case. It is also possible to use any method, such as using the flow path formed inside the shell 4 as the liquid storage part.

[0088] Furthermore, although Embodiment 1 described the case where the flow path resistance element 30 is provided as a unit for increasing the flow path resistance of the third flow path 18, this is not a limitation. Any unit can be used as long as it can increase the flow path resistance of the third flow path 18. For example, the flow path cross-sectional area of ​​the third flow path 18 can be smaller than the flow path cross-sectional area of ​​the first flow path 14 and the bypass flow path 20. This increases the resistance of the third flow path 18, promoting flow to the bypass flow path 20 and the first flow path 14. Or, as... Figure 8 As shown, a backflow prevention valve 40 can also be provided in the third flow path 18. The backflow prevention valve 40 functions to increase the flow resistance of the flow F1 in the third flow path 18 toward the second end 18B. Therefore, it can promote flow to the bypass flow path 20 and the first flow path 14. The backflow prevention valve 40 also functions to prevent flow F2 that is opposite to the flow F1. Thus, it can prevent fluid from flowing back from the tank 21 to the third flow path 18. Alternatively, as... Figure 9As shown, a mesh component 50 can also be provided in the third flow path 18. The mesh component 50 is a mesh-like component that allows gas to pass through but prevents fluid from passing through. By providing the mesh component 50, the resistance to the flow F1 in the third flow path 18 can be increased, and the flow F2 of fluid flowing back from the tank 21 can be prevented.

[0089] The above-described variations can also be applied in the following embodiment 2.

[0090] (Implementation Method 2)

[0091] The atomizer 102 according to Embodiment 2 of the present invention will be described. In Embodiment 2, the differences from Embodiment 1 will be mainly described, and descriptions that are repeated in Embodiment 1 will be omitted. In addition, for configurations that are the same as those in Embodiment 1, descriptions will be appropriately omitted using the same reference numerals.

[0092] Figure 10 This is a perspective view showing the internal structure of the atomizer 102 in Embodiment 2. Figure 11 This is an enlarged view of the connection point in the atomizer 102 of Embodiment 2. The atomizer 102 of Embodiment 2 differs from the atomizer 2 of Embodiment 1 mainly in the shape of the first flow path and the second end of the second flow path.

[0093] like Figure 10 As shown, the first flow path 114 has a first end 114A and a second end 114B. The first end 114A is connected to the outlet 10A of the first piezoelectric pump 10, and the second end 114B faces the outlet 8.

[0094] like Figure 11 As shown, the first flow path 114, starting from the upstream side, sequentially includes a first expanding flow path 118, a narrowing flow path 120, and a second expanding flow path 122. The narrowing flow path 120 is a flow path with an inner diameter that is smaller than that of the first expanding flow path 118 and the second expanding flow path 122. The narrowing flow path 120 connects the first expanding flow path 118 and the second expanding flow path 122. The end of the second expanding flow path 122 corresponds to the second end 114B of the first flow path 114.

[0095] The second flow path 116 has a first end 116A ( Figure 10 ) and the second end 116B ( Figure 11 The first end 116A is connected to the internal space of the tank 21, and the second end 116B is connected to the middle of the first flow path 114. The second end 116B of the second flow path 116 is equivalent to the connection point 123 connecting the second flow path 116 and the first flow path 114.

[0096] The second flow path 116 has, starting from the upstream side, an expanding flow path 124 and a narrowing flow path 126. The narrowing flow path 126 is a flow path with a smaller inner diameter than the expanding flow path 124. The end of the narrowing flow path 126 corresponds to the second end 116B of the second flow path 116 and forms a connection point 123.

[0097] According to the atomizer 102 having such a configuration, by simultaneously driving the first piezoelectric pump 10 and the second piezoelectric pump 12, such as Figure 10 As shown, the same flow is produced as that of atomizer 2 in Embodiment 1 (arrows A1, A2, A3, B1, B2, B3, C, D).

[0098] like Figure 11 As shown, gas flows from the first flow path 114 to the connection point 123 (arrow E1), and liquid flows from the second flow path 116 to the connection point 123 (arrow F), thus mixing the gas and liquid. The flow rates and velocities of the gas and liquid delivered to the connection point 123 are preset to values ​​that meet the atomization conditions. The gas and liquid mixed at the connection point 123 are atomized in the second expansion section 122 (arrow E2). The atomized liquid is discharged from the outlet 8 through the second end 114B of the first flow path 114 (arrow A3).

[0099] As described above, the Venturi effect can also be achieved and atomization performed at the connection point 123 in the atomizer 102 of Embodiment 2. Specifically, the first flow path 114 has a first end 114A connected to the outlet 10A of the first piezoelectric pump 10 and a second end 114B, and a connection point 123 is provided between the first end 114A and the second end 114B. Furthermore, the second flow path 116 has a first end 116A connected to the canister 21 and a second end 116B connected to the connection point 123.

[0100] With this configuration, by using the first piezoelectric pump 10 as the driving source to discharge gas, the flow rate of the discharged gas can be set by pre-setting output conditions such as the driving frequency. Therefore, compared with other types of pumps, it is easier to design to simultaneously optimize the liquid-gas mixing ratio for liquid atomization and the gas flow rate for the Venturi effect, and atomization control can be performed more easily.

[0101] Furthermore, according to the atomizer 102 of Embodiment 2, by providing narrow-diameter flow paths 120 and 126 in the first flow path 114 and the second flow path 116 respectively, the pressure and flow rate of the gas and liquid flowing in each flow path can be temporarily increased, which can promote the occurrence of the Venturi effect.

[0102] <Comparison of piezoelectric pumps and motor pumps>

[0103] The atomizers 2 and 102 of the above-described embodiments 1 and 2 use piezoelectric pumps 10 and 12 as power sources for atomization, and are superior to conventional atomizers that use motor pumps (diaphragm pumps) as power sources in the following aspects.

[0104] Specifically, in atomizers using motor pumps, the low vibration frequency results in significant pulsation, causing deviations in the particle size of the atomized liquid. Furthermore, due to the pulsation period, there are periods where the required flow rate for atomization cannot be maintained, leading to lower atomization efficiency. In contrast, in atomizers using piezoelectric pumps, the vibration frequency is high enough that pulsation is practically negligible, achieving both uniformity in the particle size of the atomized liquid and improved atomization efficiency. Regarding this point, the following will discuss... Figures 12-18 Please provide an explanation.

[0105] Figure 12 This is a graph showing the pulsation-related results when operating an atomizer using a piezoelectric pump (Example) and an atomizer using a motor pump (Comparative Example) under specified conditions. Figure 12 In the diagram, the horizontal axis represents the pulsation period (unit: none), and the vertical axis represents the gas flow rate (unit: L / min). The gas flow rate is the flow rate of gas within the atomizer driven by each pump.

[0106] like Figure 12 As shown, in the comparative example atomizer, the gas flow rate varies considerably during one cycle of pulsation. Specifically, it undergoes a sinusoidal periodic variation with a minimum flow rate of 0 L / min and a maximum flow rate of approximately 2 L / min. In contrast, in the embodiment atomizer, the gas flow rate remains almost unchanged during one cycle, maintaining an average flow rate of approximately 1 L / min.

[0107] Figure 13 This is a graph showing the relationship between gas flow rate and atomization volume in this embodiment. The horizontal axis represents the gas flow rate (unit: L / min), and the vertical axis represents the atomization volume (unit: mL / min). The atomization volume is the flow rate of the substance after the mixture of gas and liquid is atomized. Figure 13 As shown, when the gas flow rate is less than approximately 1 L / min, the atomization amount is 0. Conversely, if the gas flow rate becomes approximately 1 L / min or more, the total gas flow rate becomes the atomization amount. That is, in this embodiment, the condition for atomizing the liquid is a gas flow rate of approximately 1 L / min or more.

[0108] like Figure 12 As shown, in the comparative example atomizer, although the gas flow rate increases at approximately 1 L / min or more during the 0–0.5 cycle, the gas flow rate increases at less than approximately 1 L / min during the 0.5–1 cycle. (Refer to...) Figure 13The relationship shown indicates that in the comparative example atomizer, atomization was possible during cycles 0 to 0.5, but not during cycles 0.5 to 1. The results are as follows... Figure 14 As shown. In Figure 14 In the diagram, the horizontal axis represents the pulsation period (unit: none), and the vertical axis represents the nebulization rate (unit: mL / min). For example... Figure 14 As shown, the atomization amount corresponding to the gas flow rate can be obtained in the 0 to 0.5 cycle, but the atomization amount is 0 in the 0.5 to 1 cycle.

[0109] On the other hand, in the atomizer of the embodiment, such as Figure 12 As shown, the gas flow rate is maintained at 1 L / min during the 0-1 cycle, thus ensuring the necessary flow rate for atomization and maintaining the atomization state. The results are as follows: Figure 15 As shown. In Figure 15 In the diagram, the horizontal axis represents the pulsation period (unit: none), and the vertical axis represents the nebulization rate (unit: mL / min). For example... Figure 15 As shown, an atomization rate of approximately 1 L / min can be continuously obtained during cycles 0 to 1.

[0110] exist Figure 14 , Figure 15 In the chart shown, the area enclosed by the line representing the amount of atomization indicates the total flow rate of atomization within one cycle of the pulse. If we calculate each total flow rate, it is as follows: Figure 16 As shown. In Figure 16 In the diagram, the vertical axis represents the ratio of the total atomization flow rate within one cycle of the pulsation. According to... Figure 16 The results show that, when comparing the atomizer of the comparative example with the atomizer of the embodiment, the ratio of the total flow rate of the atomization is approximately 0.8:1.

[0111] according to Figure 16 The results show that the atomizer in this embodiment can atomize a larger total flow rate and achieve higher atomization efficiency compared to the atomizer in the comparative example.

[0112] Next, the relationship between flow rate and particle diameter is as follows: Figure 17 As shown. In Figure 17 In the graph, the horizontal axis represents the gas flow rate (unit: L / min), and the vertical axis represents the average particle size of the liquid being atomized at the flow rate on the horizontal axis (unit: μm).

[0113] like Figure 17 As shown, the higher the gas flow rate, the smaller the average particle size of the atomized liquid.

[0114] If Figure 17 The relationship between flow rate and particle size is shown in the figure. Figure 12 The result of the gas flow rate variation within one cycle of the pulsation shown is as follows: Figure 18The result shown. Figure 18 In the figure, the horizontal axis represents the particle size of the atomized liquid (unit: μm), and the vertical axis represents the presence ratio based on particle size (unit: %).

[0115] like Figure 18 As shown, in the comparative example atomizer, the particle size also deviates significantly because the gas flow rate varies considerably during one pulsation cycle. On the other hand, in the embodiment atomizer, the gas flow rate remains approximately constant during one pulsation cycle, resulting in less deviation in particle size.

[0116] according to Figure 18 The results show that the atomizer of the embodiment produces liquid with less particle size deviation, and can further homogenize the particle size compared to the atomizer of the comparative example.

[0117] As mentioned above, according to Figures 12-18 As shown, in the atomizers 2 and 102 of Embodiments 1 and 2, which use piezoelectric pumps 10 and 12 as driving sources, compared with conventional atomizers that use motor pumps as driving sources, it is possible to simultaneously achieve uniformity of the particle size of the atomized liquid and improve the atomization efficiency.

[0118] Although this disclosure has been fully described with reference to the accompanying drawings and in relation to preferred embodiments, various modifications and alterations will be apparent to those skilled in the art. Such modifications and alterations should be understood to be included therein, provided they do not depart from the scope of this disclosure based on the appended claims. Furthermore, variations in the combination and order of elements in the various embodiments can be implemented without departing from the scope and spirit of this disclosure.

[0119] This invention is useful for nebulizers used in medical and cosmetic applications.

[0120] Explanation of reference numerals in the attached figures

[0121] 2…Atomizer, 4…Housing, 4A…First housing section, 4B…Second housing section, 6…Switch, 8…Outlet, 10…First piezoelectric pump, 10A…Outlet, 12…Second piezoelectric pump, 12A…Outlet, 14…First flow path, 14A…First end of the first flow path, 14B…Second end of the first flow path, 16…Second flow path, 16A…First end of the second flow path, 16B…Second end of the second flow path, 18…Third flow path, 18A…First end of the third flow path, 18B…Second end of the third flow path, 20…Bypass flow path, 21…Canister, 22…Control Substrate, 24…connection point, 25…front end, 26…connection point, 28…connection point, 30…flow path resistance element, 32…branch flow path, 34…backflow prevention mechanism, 40…backflow prevention valve, 50…mesh component, 60…narrow section, 114…first flow path, 114A…first end, 114B…second end, 116…first flow path, 116A…first end, 116B…second end, 118…first expansion flow path, 120…contraction flow path, 122…second expansion flow path, 123…connection point, 124…expansion flow path, 126…contraction flow path.

Claims

1. An atomizer, comprising: The first piezoelectric pump discharges gas from the outlet; The first flow path is a flow path having a second end and a first end connected to the discharge port of the first piezoelectric pump, and a connection point is provided between the first end and the second end. Liquid storage section, used for storing liquid; and The second flow path has a first end connected to the liquid accumulation section and a second end connected to the connection point. The first flow path has an expansion point closer to the first end than the connection point, where the flow path diameter increases. Between the expansion point and the connection point, there is a first inclined surface that slopes in a direction that narrows the first flow path. The first inclined surface slopes from a position away from the expansion point. The aforementioned first flow path, starting from the upstream side, sequentially includes a first narrowing flow path and a first widening flow path, with the end of the first narrowing flow path constituting the widening point. The second flow path described above has a second expanding flow path and a second narrowing flow path sequentially from the upstream side. The end of the second narrowing flow path is equivalent to the second end of the second flow path and constitutes the connection point described above.

2. The atomizer according to claim 1, wherein, It also includes a branch flow path, which has a first end connected between the first end and the connection point on the first flow path, and a second end connected to the liquid accumulation section. The first flow path described above has a reduced diameter section at the location where it connects to the connection point described above.

3. The atomizer according to claim 2, wherein, The aforementioned branch flow path is equipped with a backflow prevention mechanism to prevent liquid backflow. The aforementioned reduced diameter portion is disposed on the first end side relative to the aforementioned connection point, and the aforementioned inclined surface exists between the aforementioned reduced diameter portion and the aforementioned connection point.

4. The atomizer according to claim 1, further comprising: The second piezoelectric pump discharges air from the outlet; and The third flow path has a first end connected to the discharge port of the second piezoelectric pump and a second end connected to the liquid storage section.

5. The atomizer according to any one of claims 1 to 4, wherein, The first flow path extends in a straight line from the first end of the first flow path to the second end of the first flow path.

6. The atomizer according to any one of claims 1 to 4, wherein, It also has a housing that at least accommodates the first piezoelectric pump, the first flow path, the second flow path, and the liquid storage section.

7. The atomizer according to claim 6, wherein, The liquid storage section described above is a container housed within the aforementioned shell.

8. The atomizer according to any one of claims 1 to 4, wherein, The second flow path is connected to the first flow path by intersecting the first flow path, with its front end bending inside the first flow path and extending concentrically toward the discharge outlet of the first flow path.

9. The atomizer according to claim 1, wherein, The first inclined surface is inclined to face the aforementioned diameter expansion point.

10. The atomizer according to claim 1, wherein, The first inclined surface is inclined in the direction of narrowing the diameter of the first flow path, from the first end toward the second end.

11. The atomizer according to claim 1, wherein, The first inclined surface is located between the expansion point and the connection point in the direction from the first end to the second end.

12. The atomizer according to claim 1 or 2, wherein, It also has a second inclined surface, which is connected to the second end of the first inclined surface and is inclined to the opposite side of the first inclined surface.

13. The atomizer according to claim 12, wherein, The second end of the second flow path is closer to the second end side opening than the connection point connecting the first inclined surface and the second inclined surface.

14. The atomizer according to claim 12, wherein, The second end of the second flow path opens at the second inclined surface.

15. The atomizer according to claim 13, wherein, The second end of the second flow path opens at the second inclined surface.

16. The atomizer according to claim 1, wherein, It also has a branch flow path, which has a first end connected between the first end and the connection point on the first flow path, and a second end connected to the liquid storage section.

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