Pump device

Abstract

A pump device is provided. A pump device (1) is provided with a piezoelectric pump (10) and an external housing (70). The piezoelectric pump (10) is provided with a pump housing having a suction port (400) and a discharge port (520), a vibrating plate (31) disposed inside the pump housing and dividing an internal space (500) of the pump housing into a first space (501) on the suction port (400) side and a second space (502) on the discharge port side, and a piezoelectric element (20) disposed on the vibrating plate (31). The external housing (70) forms a flow path constituted by an internal space (700) that communicates with the suction port (400) and an external flow inlet (701) that communicates with the outside. The flow path has a portion that is parallel to an outer major surface (40op) in the pump housing in which the suction port (400) is formed and is disposed on the outer side of the outer major surface (40op).

Description

[0001] This application is a divisional application of application number 2020 8 0046 213.1, filed on March 30, 2020, international application number PCT / JP2020 / 014623, entitled "Pump Device". Technical Field

[0002] The present invention relates to a pump device having a piezoelectric pump that transports fluid by vibrating a vibrating plate using a piezoelectric element. Background Technology

[0003] Patent document 1 describes a pump using a piezoelectric element. The pump includes a pump housing and a vibrating plate. The pump housing has a pump chamber inside. The vibrating plate is disposed in the pump chamber. At this time, the vibrating plate is supported by the pump housing in a vibrating state.

[0004] The vibrating plate divides the pump chamber into a first pump chamber and a second pump chamber. The first pump chamber communicates with the outside of the pump housing via an inlet formed in the pump housing. The second pump chamber communicates with the outside of the pump housing via an outlet formed in the pump housing.

[0005] The pump uses the vibration of the vibrating plate to draw in fluids such as air from outside the pump casing into the pump chamber through the suction port, and to discharge the fluids inside the pump chamber to the outside of the pump casing through the discharge port.

[0006] Patent Document 1: International Publication No. 2016 / 175185

[0007] However, the pump described in Patent Document 1 generates heat due to the vibration of the vibrating plate. Moreover, if the temperature of the pump including the vibrating plate increases, the pump operation will malfunction. Summary of the Invention

[0008] Therefore, the object of the present invention is to provide a pump device with high heat dissipation performance.

[0009] The pump device of the present invention includes a piezoelectric pump and an outer housing. The piezoelectric pump includes: a pump housing having an inlet and an outlet; a vibrating plate disposed inside the pump housing and dividing the interior space of the pump housing into a first space near the inlet and a second space near the outlet; and a piezoelectric element disposed on the vibrating plate. The outer housing forms a flow path connecting an external inlet to the inlet. A first main surface of the outer housing faces an external main surface in the pump housing where the inlet is formed. The flow path is located at least between the external main surface of the pump housing and the first main surface of the outer housing.

[0010] In this structure, the heat generated by the piezoelectric pump and transferred to the outer main surface of the wall forming the suction port in the pump housing is cooled by the fluid flowing in the flow path. The fluid before being drawn into the piezoelectric pump is at a low temperature, and the outer main surface of the wall forming the suction port has a large area, thus resulting in a higher cooling effect on the heat of the piezoelectric pump.

[0011] According to the present invention, the heat dissipation performance of the pump can be improved. Attached Figure Description

[0012] Figure 1 (A) is a top view of the pump device according to the first embodiment. Figure 1 (B) is a side sectional view showing the structure of the pump device according to the first embodiment. Figure 1 (C) is a side view of the pump device of the first embodiment.

[0013] Figure 2 This is an exploded perspective view of the pump device according to the first embodiment.

[0014] Figure 3 This is a diagram showing the general flow of fluid driven by the pump device of the first embodiment.

[0015] Figure 4 This is a coordinate graph showing the change of the intake surface temperature over time for the structure of this application and the comparative example.

[0016] Figure 5 (A) is a graph showing the relationship between the temperature of the piezoelectric pump and the fluid transport efficiency. Figure 5 (B) is a coordinate graph showing the relationship between time and attraction pressure.

[0017] Figure 6 (A) Figure 6 (B) Figure 6 (C) is a side sectional view showing the structure of the first derivative example, the second derivative example, and the third derivative example of the pump device according to the first embodiment.

[0018] Figure 7 These are five views showing the structure of a fourth derivative example of the pump device of the first embodiment.

[0019] Figure 8 This is a side sectional view showing the structure of the pump device according to the second embodiment.

[0020] Figure 9 (A) is a graph showing the change of discharge temperature over time for the structure of this application and the comparative example. Figure 9 (B) is a coordinate graph showing the relationship between time and attraction pressure.

[0021] Figure 10(A) is a side sectional view showing the structure of the pump device according to the third embodiment. Figure 10 (B) is a side sectional view showing a wiring example of the pump device according to the third embodiment.

[0022] Figure 11 This is a coordinate graph showing the change of discharge temperature over time for the structure of this application and the comparative example.

[0023] Figure 12 This is a side sectional view showing the structure of the pump device according to the fourth embodiment.

[0024] Figure 13 (A) Figure 13 (B) is a top sectional view showing the structure of the outer casing of the pump device according to the fifth embodiment.

[0025] Figure 14 This is a coordinate graph showing the change of discharge temperature over time for the structure of this application and the comparative example. Detailed Implementation

[0026] (First Implementation)

[0027] The pump device of the first embodiment of the present invention will be described with reference to the accompanying drawings. Figure 1 (A) is a top view of the pump device according to the first embodiment. Figure 1 (B) is a side sectional view showing the structure of the pump device according to the first embodiment. Figure 1 (C) is a side view of the pump device of the first embodiment. Figure 1 (B) is a side view showing the direction orthogonal to the opening surface of the external inlet. Figure 1 (C) is a side view of the opening face of the external inlet. Figure 2 This is an exploded perspective view of the pump device according to the first embodiment. Figure 3 This is a diagram showing the general flow of fluid driven by the pump device of the first embodiment.

[0028] Furthermore, in the figures shown in the following embodiments, for ease of explanation, the shape (size) of each structural element is exaggerated, either partially or entirely.

[0029] like Figure 1 (A) Figure 1 (B) Figure 1 (C) Figure 2 , Figure 3 As shown, the pump assembly 1 includes a piezoelectric pump 10 and an outer housing 70. The outer housing 70 and the piezoelectric pump 10 are in contact at the suction port 400 side of the piezoelectric pump 10.

[0030] (Structure of piezoelectric pump 10)

[0031] The piezoelectric pump 10 includes a piezoelectric element 20, a flat plate component 300 including a vibrating plate 31, a first housing component 40, a second housing component 50, and a third housing component 60.

[0032] The piezoelectric element 20 consists of a piezoelectric body in a circular plate and driving electrodes. The driving electrodes are formed on the two main surfaces of the piezoelectric body in the circular plate.

[0033] The plate component 300 includes a vibrating plate 31, a base 32, and a support portion 33. The plate component 300 is, for example, a plate made of metal or the like. The shape of the plate component 300 when viewed from above is rectangular. This top view is the main surface of the plate component 300. The plate component 300 is, for example, implemented from a single plate. That is, the vibrating plate 31, the base 32, and the support portion 33 are integrally formed from a single plate. The vibrating plate 31 is a circular plate. The base 32 is shaped to surround the outer periphery of the vibrating plate 31. The support portion 33 connects the vibrating plate 31 to the base 32. At this time, the support portion 33 connects the vibrating plate 31 to the base 32 at multiple localized locations on the outer periphery of the vibrating plate 31. With this structure, the vibrating plate 31 is supported so that it can vibrate relative to the base 32.

[0034] The first housing component 40 is, for example, a flat plate made of metal or the like. Furthermore, the material of the first housing component 40 only needs to have specified rigidity and thermal conductivity. The shape of the first housing component 40 when viewed from above is generally rectangular. This top-view surface is the main surface of the first housing component 40. The first housing component 40 has a plurality of suction ports 400. When viewed from above, the plurality of suction ports 400 overlap, for example, with the vibrating plate 31. The plurality of suction ports 400 are through holes that pass through the two main surfaces of the first housing component 40. The cross-sectional shape of the plurality of suction ports 400 parallel to the main surface of the first housing component 40 is, for example, circular. The diameter of this circle is, for example, 0.8 mm.

[0035] The second housing component 50 includes a main board 51 and a sidewall 52, and is box-shaped. The second housing component 50 is made of, for example, metal. The main board 51 and the sidewall 52 are flat plates. More specifically, the main board 51, viewed from above, is rectangular and has approximately the same area and shape as the first housing component 40. The sidewall 52 extends in a direction orthogonal to the main surface of the main board 51. The sidewall 52 is disposed along the outer periphery of the main board 51. Thus, the second housing component 50 is box-shaped. A nozzle 510 is formed on the main board 51. The nozzle 510 is cylindrical. The nozzle 510 is connected to the main surface of the main board 51 on the side opposite to the main surface of the sidewall 52.

[0036] The second housing component 50 has a discharge port 520. The discharge port 520 is a through hole that passes through the nozzle 510 and the main plate 51. When viewed from above, the discharge port 520 overlaps with, for example, the vibrating plate 31.

[0037] The third housing component 60 is a frame with a specified thickness. The shape of the third housing component 60 is approximately the same as that of the first housing component 40.

[0038] A third housing component 60 is attached to a main surface of the first housing component 40. The base 32 of the plate component 300 is attached to the third housing component 60. The sidewall 52 of the second housing component 50 is attached to the base 32 of the plate component 300. This structure creates a pump housing with an internal space 500. The internal space 500 communicates with the exterior of the pump housing on the side of the first housing component 40 via a suction port 400. The internal space 500 also communicates with the exterior of the pump housing on the side of the second housing component 50 via a discharge port 520. Additionally, as... Figure 3 As shown, the internal space 500 is divided into a first space 501 and a second space 502 by the vibrating plate 31. The first space 501 is the space on the side of the inlet 400 with the vibrating plate 31 as the reference, and the second space 502 is the space on the side of the outlet 520 with the vibrating plate 31 as the reference. The first space 501 and the second space 502 are connected by a through hole provided in the through plate member 300 of the support portion 33.

[0039] The piezoelectric element 20 is disposed on the main surface of the vibrating plate 31 near the second space 502.

[0040] In this configuration, the piezoelectric pump 10 transports the fluid as shown below. Furthermore, the principle of fluid transport is known based on previous applications by the applicant of this application, and therefore will be simplified.

[0041] The piezoelectric element 20 is connected to a control unit (not shown). This control unit generates an alternating current voltage and applies it to the piezoelectric element 20. As a result, the piezoelectric element 20 extends and retracts, causing the vibrating plate 31 to bend and vibrate. This causes a change in the volume of the first space 501 and the second space 502. Due to this change, [the following occurs / is related to...]. Figure 3 As shown, fluid is drawn into the piezoelectric pump 10 from the suction port 400 and discharged to the outside from the discharge port 520.

[0042] In this structure, the piezoelectric pump 10 generates heat due to the vibration of the vibrating plate 31. The pump device 1 of this application has an outer housing 70 as shown below, thereby enabling heat dissipation of the piezoelectric pump 10.

[0043] (Structure of outer casing 70)

[0044] like Figure 1 (A) Figure 1 (B) Figure 1 (C) Figure 2 , Figure 3As shown, the outer casing 70 includes a main plate 71, a main plate 73, side walls 721, 722, and 723. The main plates 71 and 73 are made of a material with high thermal conductivity. Furthermore, at least the main plate 73 may be made of a material with high thermal conductivity, but it is preferable that the main plate 71 is also made of a material with high thermal conductivity. The main plates 71 and 73 are configured such that their main surfaces face each other and are substantially parallel. The surface of the main plate 71 facing the main plate 73 corresponds to the "first main surface of the outer casing" of the present invention. The three edges of the outer periphery of the main plates 71 and 73 are connected by side walls 721, 722, and 723. With this structure, the outer casing 70 becomes a box-shaped structure with an internal space 700.

[0045] The outer casing 70 has an external inlet 701. The external inlet 701 is formed by areas of the main plate 71 and main plate 73 that are not connected to the side walls 721, 722, and 723. That is, in this embodiment, the external casing 70 achieves the external inlet 701 by not having a box-shaped side wall. Furthermore, for example... Figure 1 As shown in (C), the opening face of the external inlet 701 is rectangular.

[0046] The outer housing 70 has multiple outlets 730. Each outlet 730 is a through-hole passing between the two main surfaces of the main plate 73. The cross-sectional shape of the multiple outlets 730, parallel to the main surfaces of the main plate 73, is, for example, circular. The size of the outlets 730 in top view (viewed along a direction orthogonal to the opening surface) is only a fraction of the size of the suction inlet 400. The multiple outlets 730 are arranged in the same pattern as the suction inlet 400 of the piezoelectric pump 10 described above. The internal space 700 communicates with the exterior of the outer housing 70 on the main plate 73 side via the aforementioned multiple outlets 730.

[0047] (The arrangement structure of the piezoelectric pump 10 and the outer housing 70 and the function of the pump device 1)

[0048] The main plate 73 of the outer housing 70 abuts against the outer main surface 40op of the first housing component 40 of the piezoelectric pump 10. The outer main surface 40op of the first housing component 40 is the side of the first housing component 40 opposite to the main surface facing the first space 501, and is the surface that forms the outer surface of the piezoelectric pump 10.

[0049] At this time, the outer housing 70 and the piezoelectric pump 10 are configured such that the outlet 730 of the outer housing 70 overlaps (communicates) with the inlet 400 of the first housing component 40.

[0050] In this structure, as described above, when the piezoelectric pump 10 draws fluid from the suction port 400, the fluid is supplied to the suction port 400 via the external inlet 701 of the outer housing 70, the internal space 700, and the outlet 730. That is, the fluid is transported from the outside of the outer housing 70 through the external inlet 701 into the internal space 700 of the outer housing 70. The fluid passes through the internal space 700 and is transported to the outlet 730, and then flows from the outlet 730 into the suction port 400. In other words, the internal space 700 becomes the "transport path" for the fluid in this invention.

[0051] Furthermore, with the above structure, in the pump device 1, the fluid transport path in the outer housing 70 is parallel to the outer main surface 40op of the first housing component 40. Therefore, the fluid flowing in the transport path can dissipate heat from the outer main surface 40op side of the first housing component 40. At this time, the transport path and the outer main surface 40op of the first housing component 40 are opposite each other over approximately the entire surface. Therefore, heat dissipation over a large area can be achieved. Thus, the heat dissipation effect of the piezoelectric pump 10 generated by the outer housing 70 is improved.

[0052] Furthermore, the fluid flowing in the transport path is in the same state as before being drawn into the piezoelectric pump 10. Therefore, the fluid flowing in the transport path is at a lower temperature compared to the fluid inside the piezoelectric pump 10 and the fluid discharged to the outside from the outlet 520. Thus, by using the structure of the pump device 1, the first housing component 40, i.e., the piezoelectric pump 10, can dissipate heat more effectively.

[0053] Furthermore, it is preferable that the height D700 of the internal space 700 is relatively small. This allows for an increase in the velocity of the fluid transported within the transport path (internal space 700). As a result, the first housing component 40, i.e., the piezoelectric pump 10, dissipates heat more effectively. At this point, the lower limit of the height D700 is set such that the maximum amount of fluid transported within the internal space 700 is greater than or equal to the maximum amount of fluid that can be drawn in from the suction port 400, determined by the capacity of the piezoelectric pump 10. This prevents the shape of the internal space 700 from becoming a bottleneck to the capacity of the piezoelectric pump 10. Therefore, the piezoelectric pump 10 dissipates heat effectively without reducing its capacity.

[0054] Furthermore, the height D701 of the external inlet 701 is preferably greater than or equal to the height D700 of the internal space 700. Therefore, the amount of fluid supplied to the internal space 700 is not limited by the external inlet 701. Thus, the shape of the external inlet 701 can be prevented from becoming a bottleneck for the fluid transported within the internal space 700. Although a comparison between the height D701 of the external inlet 701 and the height D700 of the internal space 700 has been shown here, the shape of the external inlet 701 can also be defined using factors such as the area in a direction orthogonal to the direction of fluid transport.

[0055] Figure 4 This is a coordinate graph showing the change in intake surface temperature over time for the structure of this application and the comparative example. Figure 4 In the diagram, the horizontal axis represents the elapsed time since the piezoelectric pump 10 was started, and the vertical axis represents the suction surface temperature of the piezoelectric pump 10, i.e., the temperature of the outer main surface 40op of the first housing component 40. Furthermore, the comparative example shows a structure without the heat dissipation structure of the present invention.

[0056] like Figure 4 As shown, in both the present invention and the comparative invention, the temperature of the suction surface increases over time. However, by using the present invention, the rate of temperature rise can be reduced, thereby lowering the reached temperature. For example, the piezoelectric pump 10 sets an upper limit temperature Tth for stopping operation to prevent malfunction. This upper limit temperature Tth was reached in the comparative example, but not in the present invention. Therefore, compared to the conventional comparative example, the piezoelectric pump 10 can operate stably for a longer period of time.

[0057] In addition, Figure 4 The pump device 1 of the first embodiment and the pump device 1C of the second embodiment described later are shown in the figure (see reference). Figure 8 The characteristics of the piezoelectric pump 10. In simple terms, the pump device 1C of the second embodiment has a structure where the side of the piezoelectric pump 10 also abuts against the outer housing 70C. The area of ​​the outer main surface 40op of the piezoelectric pump 10 is large, while the area of ​​the side surface is smaller than that of the outer main surface 40op. Furthermore, in a configuration where the vibrating plate 31 is close to the first housing component 40, and the vibrating plate 31 and the first housing component 40 are further close due to vibration, the heat from the vibrating plate 31 is mainly transferred to the first housing component 40. In this case, as... Figure 4 As shown, compared to the structure of the pump device 1C using the second embodiment, the heat dissipation effect of the first housing component 40 at the same flow rate is improved by using the structure of the pump device 1 of the first embodiment. That is, by using the structure of the pump device 1, the heat dissipation effect of the suction surface relative to the specified flow rate is improved.

[0058] Figure 5 (A) is a coordinate graph representing the relationship between the temperature of the piezoelectric pump and the fluid transport efficiency. Figure 5 (B) is a graph showing the relationship between elapsed time and suction pressure. Suction pressure represents the pressure of the suction device that uses a piezoelectric pump for suction.

[0059] like Figure 5 As shown in (A), the conveying efficiency of the piezoelectric pump decreases with increasing temperature. Therefore, as Figure 5As shown in (B), by using the structure of the piezoelectric pump 10, the starting time of the suction pressure reduction is later than that of the comparative example. That is, compared with the suction device using the comparative example, the suction device using the piezoelectric pump 10 can maintain the specified suction pressure for a longer period of time.

[0060] (A derivative example of the structure of the pump device in the first embodiment)

[0061] Figure 6 (A) is a side sectional view showing the structure of a first derivative example of the pump device according to the first embodiment. Figure 6 (B) is a side sectional view showing the structure of a second derivative example of the pump device of the first embodiment. Figure 6 (C) is a side sectional view showing the structure of a third derivative example of the pump device of the first embodiment. Figure 7 These are five views showing the structure of a fourth derivative example of the pump device according to the first embodiment.

[0062] Compared to the pump device 1 described above, Figure 6 The pump assembly 1A1 shown in (A) differs in structure from the outer housing 70A1. The other structures of the pump assembly 1A1 are the same as those of the pump assembly 1, therefore descriptions of the same locations are omitted.

[0063] Compared to the outer housing 70, the outer housing 70A1 differs in that it has an external inlet 702. The external inlet 702 is located in the outer housing 70A1 at a different position than the external inlet 701. With this structure, the outer housing 70A1 has multiple external inlets.

[0064] Even with this structure, the pump unit 1A1 can achieve the same heat dissipation effect as the pump unit 1 described above. Furthermore, by having multiple external inlets, the outer housing 70A1 can more reliably prevent the external inlets from becoming bottlenecks in the fluid transport process.

[0065] Compared with the pump device 1 described above, Figure 6 The pump assembly 1A2 shown in (B) differs in the structure of its outer housing 70A2. The other structures of the pump assembly 1A2 are the same as those of the pump assembly 1, therefore descriptions of identical parts are omitted.

[0066] The outer housing 70A2 has an opening on the main plate 73 at a position where it overlaps with the first housing component 40 of the piezoelectric pump 10. The first housing component 40 blocks the opening of the main plate 73. That is, the first housing component 40 is exposed to the interior space 700 side of the outer housing 70A2, becoming part of the wall forming the interior space 700 of the outer housing 70A2.

[0067] Therefore, the fluid flowing in the internal space 700, i.e., the flow path, comes into direct contact with the outer main surface 40op of the first housing component 40. As a result, the heat dissipation effect of the first housing component 40 is improved.

[0068] Compared with the pump device 1 described above, Figure 6 The pump assembly 1A3 shown in (C) differs in the structure of its outer housing 70A3. The other structures of the pump assembly 1A3 are the same as those of the pump assembly 1, therefore descriptions of the same locations are omitted.

[0069] The outer housing 70A3 has an opening on the main plate 73 at a position where it overlaps with the first housing component 40 of the piezoelectric pump 10. The area of ​​this opening is smaller than the area of ​​the outer main surface 40op of the first housing component 40. With this structure, the outer main surface 40op of the first housing component 40 abuts against the main plate 73 and the side wall 723 at a partial location on its outer peripheral end side. In this case, a portion of the first housing component 40 is exposed to the interior space 700 side of the outer housing 70A3, becoming a portion of the wall forming the interior space 700 of the outer housing 70A3.

[0070] Therefore, the fluid flowing in the internal space 700, i.e., the flow path, comes into direct contact with the outer main surface 40op of the first housing component 40. This improves the heat dissipation effect of the first housing component 40. Furthermore, in this case, the outer main surface 40op of the first housing component 40 abuts against the outer housing 70A3 at its outer peripheral end. This facilitates the installation of the first housing component 40 onto the outer housing 70A3.

[0071] Compared to the pump device 1 described above, Figure 7 The pump assembly 1B shown differs in the structure of its outer housing 70B. The other structures of the pump assembly 1B are the same as those of the pump assembly 1, therefore descriptions of the same locations are omitted.

[0072] The outer housing 70B includes a main plate 710 and a plurality of columnar members 790. The main plate 710 is arranged at intervals and parallel to each other on the outer main surface 40op of the first housing member 40 of the piezoelectric pump 10. The main plate 710 and the first housing member 40 are connected by the plurality of columnar members 790.

[0073] In this structure, the space 700B between the first housing component 40 and the main plate 710 serves as a flow path. Furthermore, an external inlet 701B is located on the same surface as the side of the piezoelectric pump 10 within the space 700B. Even with this structure, the pump device 1B achieves the same heat dissipation effect as the pump device 1 described above. Moreover, in this structure, the outer main surface 40op of the first housing component 40 of the piezoelectric pump 10 serves as the wall of the flow path. Therefore, heat dissipation efficiency is improved. Additionally, this structure simplifies the structure of the outer housing 70B. Furthermore, in this structure, the main plate 710 can be implemented using the outer wall of the machine where the piezoelectric pump 10 is installed. Therefore, the aforementioned heat dissipation effect can be achieved simply by installing the piezoelectric pump 10 into the machine.

[0074] (Second Implementation)

[0075] The pump device of the second embodiment will be described with reference to the accompanying drawings. Figure 8 This is a side sectional view showing the structure of the pump device according to the second embodiment.

[0076] Compared to the pump device 1 of the first embodiment, such as Figure 8 As shown, the pump device 1C of the second embodiment differs in the structure of the outer housing 70C. The other structures of the pump device 1C are the same as those of the pump device 1, therefore descriptions of the same locations are omitted.

[0077] Compared to the outer housing 70, the outer housing 70C differs in the shape of the main board on the piezoelectric pump 10 side. The main plate 71C has the same shape as the main plate 71, while the side wall 723C has a shape that is modified according to the shape of the main board on the piezoelectric pump 10 side. Additionally, the side walls (not shown) also have shapes that are modified according to the shape of the main board on the piezoelectric pump 10 side, modifying the aforementioned side walls 721 and 722.

[0078] The main plate on the piezoelectric pump 10 side includes a first plate portion 731C, a second plate portion 732C, and a third plate portion 733C. The first plate portion 731C abuts against the outer main surface 40op of the first housing component 40. The second plate portion 732C abuts against the outer side surface 50sf of the pump housing. The third plate portion 733C is connected to the end of the second plate portion 732C opposite to the end connected to the first plate portion 731C. The third plate portion 733C is parallel to and opposite to the main plate portion 71C.

[0079] With this structure, the internal space 700C of the outer casing 70C has a first space 7001 and a second space 7002. The space formed by the first space 7001 and the second space 7002 corresponds to the "flow path" of the present invention.

[0080] The first space 7001 runs along the outer main surface 40op of the first housing component 40, and the second space 7002 runs along the outer side surface 50sf of the pump housing. With this structure, the piezoelectric pump 10 dissipates heat via the outer main surface 40op of the first housing component 40 and the outer side surface 50sf of the pump housing. Therefore, the pump assembly 1C can dissipate heat from the piezoelectric pump 10 in the same way as the pump assembly 1.

[0081] Figure 9 (A) is a graph showing the change in discharge temperature over time for the structure of this application and the comparative example. Figure 9 In (A), the horizontal axis represents the elapsed time since the piezoelectric pump 10 was started, and the vertical axis represents the discharge temperature of the piezoelectric pump 10, i.e., the temperature of the discharge port 520 of the piezoelectric pump 10. Furthermore, the comparative example shows a structure that does not have the heat dissipation structure of the present invention. Figure 9 (B) is a coordinate graph showing the relationship between time and attraction pressure.

[0082] like Figure 9 As shown in (A), compared to the comparative example, the structure of pump device 1C results in a lower rate of temperature rise at discharge and a lower arrival temperature. Accompanying this, as... Figure 9 As shown in (B), compared with the comparative example, the structure of the pump device 1C can maintain the specified suction pressure for a long time.

[0083] Furthermore, compared to the pump device 1 of the first embodiment, by having the structure of pump device 1C, the rate of increase in discharge temperature is reduced, and the arrival temperature is lowered. Accompanying this, such as... Figure 9 As shown in (B), compared with pump device 1, the structure of pump device 1C can maintain the specified suction pressure for a longer time.

[0084] Additionally, in this structure, such as Figure 8 As shown, the height of the external inlet 701C can be made greater than the height of the first space 7001 that communicates with the outlet 730. Therefore, it is possible to prevent the external inlet 701C from becoming a bottleneck for fluid transport.

[0085] (Third Implementation)

[0086] The pump device of the third embodiment will be described with reference to the accompanying drawings. Figure 10 (A) is a side sectional view showing the structure of the pump device according to the third embodiment. Figure 10 (B) is a side sectional view showing a wiring example of the pump device according to the third embodiment.

[0087] like Figure 10 (A) Figure 10As shown in (B), the pump device 1D of the third embodiment differs from the pump device 1 of the first embodiment in that it includes multiple piezoelectric pumps 10. The other structures of the pump device 1D are the same as those of the pump device 1, so descriptions of the same locations are omitted.

[0088] The pump assembly 1D includes multiple piezoelectric pumps 10 and an outer housing 70D. The outer housing 70D includes a main plate 71D and a main plate 73D, and has an internal space 700D. The main plate 71D and the main plate 73D are shaped to allow the multiple piezoelectric pumps 10 to be arranged in a configuration.

[0089] Multiple piezoelectric pumps 10 are configured such that their respective outer main surfaces 40op are on the same surface and abut against the main plate 73D. The main plate 73D and the multiple piezoelectric pumps 10 each have a corresponding outlet 730. The multiple outlets 730 are respectively connected to multiple suction ports 400 of the multiple piezoelectric pumps 10.

[0090] Here, in a direction parallel to the main surface of the main plate 73D, a plurality of piezoelectric pumps 10 are arranged sequentially away from the external flow inlet 701. Thus, the plurality of piezoelectric pumps 10 are arranged in the direction of fluid transport in the flow path.

[0091] Figure 11 This is a coordinate graph showing the change in discharge temperature over time for the structure of this application and the comparative example. Figure 11 In this context, N represents the number of piezoelectric pumps 10. For example... Figure 11 As shown, compared to a structure with one piezoelectric pump 10, configuring multiple piezoelectric pumps 10 reduces the rate of increase in discharge temperature and the arrival temperature of the discharge temperature. Furthermore, increasing the number of piezoelectric pumps 10 further enhances the reduction in both the rate of increase in discharge temperature and the arrival temperature.

[0092] In addition, such as Figure 10 As shown in (B), in the pump assembly 1D, the wiring electrodes of the piezoelectric elements 20 for the plurality of piezoelectric pumps 10 are shared. Specifically, the piezoelectric element 20 includes a piezoelectric body 21, a first electrode 22, and a second electrode 23. The first electrode 22 and the second electrode 23 are configured to clamp the piezoelectric body 21. The piezoelectric element 20 is disposed on a vibrating plate 31 and the second electrode 23 abuts against the vibrating plate 31.

[0093] The outer housing 70D has a common electrode 290 on the outer main surface of the main plate 73D. The second electrode 23 is connected to the common electrode 290 via a wiring electrode 280 formed in the pump housing, etc. With this structure, even if multiple piezoelectric pumps 10 are provided, the drive wiring in the pump device 1D can be simplified.

[0094] (Fourth Implementation)

[0095] The pump device of the fourth embodiment will be described with reference to the accompanying drawings. Figure 12 This is a side sectional view showing the structure of the pump device according to the fourth embodiment.

[0096] like Figure 12 As shown, the pump device 1E of the fourth embodiment differs from the pump device 1D of the third embodiment in the structure of the outer housing 70E. The other structures of the pump device 1E are the same as those of the pump device 1D, therefore descriptions of the same locations are omitted.

[0097] Pump unit 1E is in Figure 10 The pump device 1D shown is used in the structure Figure 8 The outer housing of the pump device 1C shown is configured in the shape of the outer casing. Specifically, the outer casing 70E of the pump device 1E includes a main plate 71E, a first plate portion 731E, a second plate portion 732E, and a third plate portion 733E. The sidewall 723E has the same structure as the sidewall 723C described above. Multiple first plate portions 731E abut against the outer main surfaces 40op of multiple piezoelectric pumps 10. Multiple second plate portions 732E abut against the outer side surfaces 50sf of the pump housings of multiple piezoelectric pumps 10. Multiple third plate portions 733E abut against the multiple second plate portions 732E. With this structure, the outer casing 70E has an internal space 700E. The internal space 700E has a first space 7001 and multiple second spaces 7002. The first space 7001 is a space parallel to the outer main surfaces 40op of the first housing components 40 of the multiple piezoelectric pumps 10. The second space 7002 is a space parallel to the outer surface 50sf of the pump housing of the plurality of piezoelectric pumps 10. Moreover, the internal space 700E is connected to the outside of the outer housing 70E via the external inlet 701E.

[0098] Even with this structure, pump unit 1E can achieve the same heat dissipation effect as pump unit 1D. In addition, multiple piezoelectric pumps 10 also dissipate heat from the side walls, thus achieving an even higher heat dissipation effect.

[0099] (Fifth Implementation)

[0100] The pump device of the fifth embodiment will be described with reference to the accompanying drawings. Figure 13 (A) Figure 13 (B) is a top sectional view showing the structure of the outer casing of the pump device according to the fifth embodiment. The pump device of the fifth embodiment differs from those of the other embodiments in the construction of its outer casing. The other structures of the pump device of the fifth embodiment are the same as those of the other embodiments, therefore descriptions of the same locations are omitted.

[0101] Figure 13The outer housing 70F of the pump assembly shown in (A) includes sidewalls 721, 722, 723, 724, and a partition wall 725. Sidewalls 721, 722, 723, 724, and 725 are connected to the main plate 71 and extend in a direction orthogonal to the main surface of the main plate 71. Furthermore, although not shown, sidewalls 721, 722, 723, 724, and 725 are connected to the main plate 73 opposite to the main plate 71.

[0102] Sidewalls 721, 722, 723, and 724 are formed along the outer periphery of the main plate 71. Sidewall 721 is opposite to sidewall 722, and sidewall 723 is opposite to sidewall 724. Sidewall 723 is connected to sidewalls 721 and 722. Sidewall 724 is connected to sidewall 721 but not to sidewall 722, and a gap exists between sidewall 724 and sidewall 722. This gap becomes the external inlet 701F.

[0103] The partition wall 725 is connected to the end of the side wall 724 near the side wall 722, dividing the internal space 700F into a coiled shape and a meandering shape. Thus, the fluid flow path is formed in a shape that connects the coiled, cylindrical flow path and the meandering, cylindrical flow path. Furthermore, the inlet of this flow path becomes the external flow inlet 701F, and multiple outlets 730 are disposed along the middle of the flow path.

[0104] This structure allows for a faster flow rate of the fluid flowing in the flow path within the outer casing 70F. This improves the heat dissipation effect of the piezoelectric pump 10. Furthermore, sidewalls 721, 722, 723, 724, and partition wall 725 are formed from a material with high thermal conductivity, such as metal. Thus, sidewalls 721, 722, 723, 724, and partition wall 725 function as heat sinks. Therefore, the heat dissipation effect of the piezoelectric pump 10 is further improved. In particular, the partition wall 725 is positioned relatively long along the flow path, thus functioning more effectively as a heat sink. Therefore, the heat dissipation effect of the piezoelectric pump 10 is further improved.

[0105] Figure 14 This is a coordinate graph showing the change in discharge temperature over time for the structure of this application and the comparative example. Figure 14 In the diagram, the horizontal axis represents the elapsed time since the piezoelectric pump 10 started operating, and the vertical axis represents the discharge temperature of the piezoelectric pump 10, i.e., the temperature of the discharge port 520 of the piezoelectric pump 10. Furthermore, the comparative examples show structures without the heat dissipation structure of the present invention. Additionally, the characteristics of the structure of Embodiment 1 are also shown as a preferred comparative example of a heat sink.

[0106] like Figure 14As shown, with the structure of the fifth embodiment, the rate of increase in exhaust temperature and the arrival temperature are reduced. That is, compared with the comparative structure and the structure without heat sinks, the heat dissipation effect is improved.

[0107] In addition, Figure 13 In (A), the partition wall 725 is formed in a coiled shape and a spiral shape. However, the shape of the partition wall 725 is not limited to this, and can also be a coiled shape, a spiral shape, or other shapes that can arrange multiple outlets 730 in the middle of the flow path and can form a cylindrical shape.

[0108] Figure 13 The outer housing 70G of the pump device shown in (B) includes sidewalls 721, 722, 7231, 7232, 7241, partition wall 725G1, and partition wall 725G2. Sidewalls 721, 722, 7231, 7232, 7241, 725G1, and 725G2 are connected to the main plate 71 and extend in a direction orthogonal to the main surface of the main plate 71. Furthermore, although not shown, sidewalls 721, 722, 7231, 7232, 7241, 725G1, and 725G2 are connected to the main plate 73 opposite to the main plate 71.

[0109] Sidewalls 721, 722, 7231, 7232, and 7241 are formed along the respective sides forming the outer periphery of the main plate 71. Sidewall 721 and sidewall 722 are opposite each other. Sidewalls 7231 and 7232 are located on the same side of the main plate 71. Sidewall 7241 is located on the side opposite to the side on which sidewalls 7231 and 7232 are arranged.

[0110] Partition walls 725G1 and 725G2 are disposed between sidewalls 721 and 722, and are parallel to sidewalls 721 and 722. Partition wall 725G1 is disposed on the side closer to sidewall 721 than partition wall 725G2.

[0111] Side wall 721 is connected to side wall 7231, and side wall 7231 is connected to partition wall 725G1. Partition wall 725G1 is connected to side wall 7241, and side wall 7241 is connected to partition wall 725G2. Partition wall 725G2 is connected to side wall 7232, and side wall 7232 is connected to side wall 722.

[0112] This structure forms an internal space 700G1 enclosed in the lateral direction by sidewalls 721, 7231, and partition wall 725G1. The internal space 700G1 communicates with the outside via an external inlet 701G1 formed by the gap between sidewalls 721 and 7241. The internal space 700G1 also communicates with an outlet 7301.

[0113] Additionally, an internal space 700G2 is formed, enclosed in the lateral direction by partition wall 725G1, side wall 7241, and partition wall 725G2. The internal space 700G2 communicates with the outside via an external inlet 701G2 formed by the gap between side wall 7231 and side wall 7232. The internal space 700G2 also communicates with an outlet 7302.

[0114] Additionally, an internal space 700G3 is formed, enclosed in the lateral direction by a partition wall 725G2, a side wall 7232, and a side wall 722. The internal space 700G3 communicates with the outside via an external inlet 701G3 formed by the gap between the side walls 7241 and 722. The internal space 700G3 communicates with an outlet 7303.

[0115] By forming this structure, flow paths can be formed independently relative to outlets 7301, 7302, and 7303. Furthermore, in this structure, the sidewalls 721, 722, 7231, 7232, 7241, partition wall 725G1, and partition wall 725G2 further improve the heat dissipation effect of the piezoelectric pump 10. In particular, the heat dissipation effect of the piezoelectric pump 10 is further improved by having partition walls 725G1 and 725G2.

[0116] Furthermore, the structure of the partition wall is not limited to this; it is sufficient as long as there is at least one partition wall with high thermal conductivity.

[0117] Furthermore, the structures of the above-described embodiments can be appropriately combined to obtain the corresponding effects of each combination.

[0118] Explanation of reference numerals in the attached figures:

[0119] 1. 1A1, 1A2, 1A3, 1B, 1C, 1D, 1E... Pump device; 10... Piezoelectric pump; 20... Piezoelectric element; 21... Piezoelectric body; 22... First electrode; 23... Second electrode; 31... Vibrating plate; 32... Base; 33... Support; 40... Component for first housing; 40op... Outer main surface; 50... Component for second housing; 50sf... Outer side; 51... Main board; 52... .Sidewall; 60...Third housing component; 70, 70A1, 70A2, 70A3, 70B, 70C, 70D, 70E, 70F, 70G...Outer housing; 71, 71C, 71D, 71E, 73, 73D...Main plate; 280...Wiring electrode; 290...Common electrode; 300...Plate component; 400...Inlet; 500...Internal space; 501...First space; 502...Second Space; 510... Nozzle; 520... Exhaust port; 700, 700C, 700D, 700E, 700F, 700G1, 700G2, 700G3... Internal space; 701, 701B, 701C, 701E, 701F, 701G1, 701G2, 701G3, 702... External inlet; 710... External inlet; 710... Main plate; 721, 722, 723, 723C, 723 E, 724, 7231, 7232, 7241... Sidewalls; 725, 725G1, 725G2... Partition walls; 730... Outlet; 731C, 731E... First plate section; 732C, 732E... Second plate section; 733C, 733E... Third plate section; 790... Columnar component; 7001... First space; 7002... Second space; 7301, 7302, 7303... Outlet.

Claims

1. A pump device, wherein, have: A piezoelectric pump comprising a pump housing having an inlet and an outlet, a vibrating plate disposed inside the pump housing, and a piezoelectric element disposed on the vibrating plate; and The outer casing forms a flow path that connects an external inlet to the outside and the suction port. The first main surface of the outer casing faces the outer main surface of the pump casing where the suction port is formed. The flow path is located at least between the outer main surface of the pump housing and the first main surface of the outer housing. The outer casing has sidewalls and partition walls protruding from the sidewalls. The flow path further comprises a portion enclosed by a main plate forming the first main surface, a sidewall in the outer housing that faces the outer side of the pump housing opposite to the outer main surface where the suction port is formed, and a third plate portion connected to the end of the sidewall opposite to the end connected to the main plate.

2. The pump device according to claim 1, wherein, The flow path will have the surface that abuts against the outer main surface as a wall surface forming the flow path.

3. The pump device according to claim 1 or 2, wherein, It is equipped with multiple piezoelectric pumps, Multiple piezoelectric pumps are arranged such that the outer main surface is coplanar with the outer housing.

4. The pump device according to claim 1 or 2, wherein, The wall of the pump housing in which the suction port is formed is made of metal.

5. The pump device according to claim 1 or 2, wherein, The outer casing has multiple external flow inlets.

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