Piezoelectric pump and electronic device

Abstract

The application relates to a piezoelectric pump and an electronic device. The piezoelectric pump comprises a cover plate provided with an air outlet, a base provided with an air inlet, a containing cavity formed by the cover plate and the base, the air outlet and the air inlet being communicated with the containing cavity, a vibration assembly comprising a vibration plate and an elastic sheet, the first side of the vibration plate facing the base, the first side of the vibration plate being provided with an annular groove, the annular groove being provided with a first through hole, the elastic sheet being arranged on the first side of the vibration plate and provided with a second through hole, a fixed area formed by the area outside the contour of the annular groove, the elastic sheet and the vibration plate being clamped and fixed between the cover plate and the base, a convex part formed by the area inside the contour of the annular groove, and a gap between the convex part and the elastic sheet.

Description

Technical Field

[0001] This application relates to the field of piezoelectric pump technology, and more specifically, to a piezoelectric pump and electronic device. Background Technology

[0002] Existing piezoelectric pumps typically rely on the vibration of piezoelectric transducers to change the volume of the pump chamber, using a check valve to achieve fluid delivery. However, the transducer plates of existing piezoelectric pumps are usually connected to the housing via independently designed support layers, resulting in increased structural layers and consequently, complex assembly and low internal space utilization. Moreover, due to the limitations of the transducer plate's connection structure and support method, there is an inherent contradiction between the effective vibration area of ​​the piezoelectric ceramic and the overall volume of the pump body; that is, it is difficult to simultaneously maximize the configuration of the vibration area and effectively improve pumping capacity within the limited pump body space. Summary of the Invention

[0003] This application provides a new technical solution for piezoelectric pumps, which can at least solve the problem of multiple structural layers caused by the setting of independent support connection layers in existing piezoelectric pumps.

[0004] This application also provides a new technical solution for an electronic device.

[0005] According to a first aspect of this application, a piezoelectric pump is provided, comprising: a cover plate having an air outlet; a base having an air inlet, the cover plate and the base forming a receiving cavity, the air outlet and the air inlet both communicating with the receiving cavity; and a vibration assembly including a vibrating plate and a spring plate, a first side of the vibrating plate facing the base, the first side of the vibrating plate having an annular groove having a first through hole, the spring plate being disposed on the first side of the vibrating plate having a second through hole; the area of ​​the vibrating plate outside the outer contour of the annular groove forming a fixing area, the spring plate being clamped and fixed between the cover plate and the base; and a protrusion forming within the inner contour of the annular groove, the protrusion having a gap with the spring plate.

[0006] Optionally, the vibration assembly further includes a piezoelectric ceramic disposed on the second side of the vibrating plate, wherein the first through hole is located outside the outer contour of the piezoelectric ceramic.

[0007] Optionally, the annular groove is provided with a plurality of first through holes, and the plurality of first through holes are arranged in annular array on the outer periphery of the piezoelectric ceramic.

[0008] Optionally, the depth of the annular groove is 10% to 40% of the thickness of the vibrating plate.

[0009] Optionally, the diameter of the first through hole is 2% to 10% of the diameter of the vibrating plate.

[0010] Optionally, the piezoelectric pump further includes: a flexible circuit board and a gasket, wherein the flexible circuit board and the gasket are clamped and fixed between the cover plate and the vibrating plate; the gasket is located between the vibrating plate and the flexible circuit board, and the flexible circuit board is electrically connected to the piezoelectric ceramic.

[0011] Optionally, the sidewall of the fixed area is provided with a protrusion, the protrusion being electrically connected to the side of the piezoelectric ceramic near the vibrating plate, and the flexible circuit board being electrically connected to the side of the piezoelectric ceramic away from the vibrating plate.

[0012] Optionally, the piezoelectric ceramic has a first electrode and a second electrode on the side near the vibrating plate, and the piezoelectric pump further includes a flexible circuit board, which is clamped and fixed between the piezoelectric ceramic and the vibrating plate, and the first electrode and the second electrode are electrically connected to the flexible circuit board respectively.

[0013] Optionally, the flexible circuit board is bonded and fixed between the piezoelectric ceramic and the vibrating plate.

[0014] Optionally, the spring is bonded between the fixing area and the base; and / or, the distance between the protrusion and the spring is 5μm-20μm.

[0015] According to a second aspect of this application, an electronic device is provided, comprising the piezoelectric pump described in any of the preceding claims.

[0016] According to the piezoelectric pump of this application, by creating an annular groove in the vibrating plate, the vibrating plate is integrally divided into a fixed area and a vibration area. The vibrating plate, along with the spring sheet, is clamped and assembled between the base and the cover plate using its own fixed area, eliminating the need for additional connecting layers. This simplifies the overall structural hierarchy, thereby freeing up internal assembly space for the piezoelectric pump. While meeting the same pumping flow and pressure performance requirements, the overall size of the piezoelectric pump can be reduced, achieving a miniaturized design while ensuring sufficient pumping capacity. Furthermore, the vibrating plate can form a near-edge-fixed vibration mode at the operating frequency. This vibration mode is a knotless circular mode, concentrating vibration energy in the vibration area, reducing energy loss at the boundary, improving overall vibration response efficiency, and making the pressure changes in the working chamber more dramatic and controllable, effectively improving overall pumping efficiency.

[0017] Other features and advantages of this application will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the present application and, together with their description, serve to explain the principles of the present application.

[0019] Figure 1This is one of the structural schematic diagrams of a piezoelectric pump according to an embodiment provided in this application; Figure 2 This is a second schematic diagram of the structure of a piezoelectric pump according to an embodiment provided in this application; Figure 3 This is a third schematic diagram of the structure of a piezoelectric pump according to an embodiment provided in this application; Figure 4 This is a fourth schematic diagram of the structure of a piezoelectric pump according to an embodiment provided in this application; Figure 5 a is a schematic diagram of the vibration modes of the existing vibrating plate during operation. Figure 5 b is a schematic diagram of the vibration modes of the vibrating plate in the embodiment of this application during operation.

[0020] Explanation of reference numerals in the attached figures 10. Cover plate; 11. Air outlet; 20. Base; 21. Air inlet; 30. Vibration assembly; 31. Vibrating plate; 311. Annular groove; 312. First through hole; 313. Protrusion; 32. Spring; 321. Second through hole; 33. Piezoelectric ceramic; 331. First electrode; 332. Second electrode; 40. Flexible circuit board; 50. Washer. Detailed Implementation

[0021] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present application.

[0022] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the scope of this application and its application or use.

[0023] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0024] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0025] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0026] The piezoelectric pump according to an embodiment of this application will now be described in detail with reference to the accompanying drawings.

[0027] like Figure 1 and Figure 2 As shown, the piezoelectric pump according to an embodiment of this application includes: a cover plate 10, a base 20, and a vibration assembly 30.

[0028] Specifically, the cover plate 10 is provided with an air outlet 11; the base 20 is provided with an air inlet 21, and the cover plate 10 and the base 20 enclose a receiving cavity, wherein both the air outlet 11 and the air inlet 21 are connected to the receiving cavity; the vibration assembly 30 includes a vibrating plate 31 and a spring plate 32, the first side of the vibrating plate 31 faces the base 20, the first side of the vibrating plate 31 is provided with an annular groove 311, the annular groove 311 is provided with a first through hole 312, the spring plate 32 is provided on the first side of the vibrating plate 31, the spring plate 32 is provided with a second through hole 321; the area of ​​the vibrating plate 31 outside the outer contour of the annular groove 311 forms a fixing area, and the spring plate 32 and the vibrating plate 31 are clamped and fixed between the cover plate 10 and the base 20; the area of ​​the vibrating plate 31 inside the inner contour of the annular groove 311 forms a protrusion, and there is a gap between the protrusion and the spring plate 32.

[0029] In other words, the piezoelectric pump according to the embodiments of this application mainly consists of a housing and a vibration assembly 30. The housing is a cylindrical structure, mainly including a base 20 and a cover plate 10, with a cavity formed between the base 20 and the cover plate 10. The bottom of the base 20 has an air inlet 21 that extends through the thickness of the base 20, communicating with the cavity. The top of the cover plate 10 has an air outlet 11 that extends through the thickness of the cover plate 10, communicating with the cavity. The vibration unit mainly consists of a vibrating plate 31 and a spring sheet 32. The vibrating plate 31 has a first side and a second side arranged opposite each other in its thickness direction. The first side of the vibrating plate 31 has an annular groove 311 coaxially arranged with the vibrating plate 31, and the bottom of the annular groove 311 has a through hole 312.

[0030] The area between the outer contour of the annular groove 311 and the outer contour of the vibrating plate 31 forms a fixed area. The area within the outer contour of the annular groove 311 forms a vibration area. The area within the inner contour of the annular groove 311 forms a protrusion, which is the part with the greatest vibration deflection. The spring piece 32 is located on the first side of the vibrating plate 31. The outer peripheral area of ​​the spring piece 32 can be fixed to the fixed area by adhesive bonding. There is a gap between the central area of ​​the spring piece 32 and the protrusion. An action cavity is formed between the spring piece 32 and the inner wall surface of the annular groove 311. The central area of ​​the spring piece 32 is provided with a second through hole 321 that is closed by the protrusion. The fixed area and the spring piece 32 are clamped and fixed between the base 20 and the cover plate 10. The spring piece 32 is located on the side of the fixed area closer to the base 20, so that the first through hole 312 communicates with the air outlet 11 and the second through hole 321 communicates with the air inlet 21.

[0031] When the piezoelectric pump according to the embodiment of this application is working, the vibration zone of the vibrating plate 31 can be driven to produce bending deformation. At the same time, the spring 32 will lag behind the vibration zone by a certain phase and vibrate at the same frequency, thereby causing the working chamber to produce drastic pressure changes, forming periodically alternating positive and negative pressures, thereby driving the gas flow.

[0032] The existing vibrating plate is connected to the shell through an elastic connecting layer, and its vibration modes are as follows: Figure 5 As shown in a; the vibration modes corresponding to the working state of the vibrating plate 31 in this embodiment of the application are as follows: Figure 5 As shown in b. From Figure 5 a and Figure 5 As can be seen from b, the vibration mode of the existing vibrating plate is the pitch circle mode, while the vibration mode of the vibrating plate 31 in this application is the pitch circle-free mode.

[0033] Therefore, according to the piezoelectric pump provided in this embodiment, by opening an annular groove 311 in the vibrating plate 31, the vibrating plate 31 is integrally divided into a fixed area and a vibration area. The vibrating plate 31, together with the spring piece 32, is clamped and assembled between the base 20 and the cover plate 10 by means of its own fixed area, without the need for additional connecting layers, which simplifies the overall structural hierarchy and frees up the internal assembly space of the piezoelectric pump. Under the premise of meeting the same pumping flow and pressure performance, the overall size of the piezoelectric pump can be reduced, realizing a miniaturized design, while ensuring sufficient pumping capacity. In addition, the vibrating plate 31 can form a quasi-edge-fixed vibration mode at the working frequency. This vibration mode is a knotless circular mode, and the vibration energy is concentrated in the vibration area, reducing energy loss at the boundary and improving the overall vibration response efficiency. This makes the pressure change in the working chamber more intense and controllable, which can effectively improve the overall pumping efficiency.

[0034] In some specific embodiments of this application, the vibration assembly 30 further includes a piezoelectric ceramic 33, which is disposed on the second side of the vibrating plate 31, and the first through hole 312 is located outside the outer contour of the piezoelectric ceramic 33.

[0035] Specifically, the vibration assembly 30 includes a vibrating plate 31, a spring sheet 32, and a piezoelectric ceramic 33. The piezoelectric ceramic 33 is fixed to the side of the vibration zone near the cover plate 10. The piezoelectric ceramic 33 can generate an inverse piezoelectric effect under the action of AC voltage, thereby driving the vibration zone to produce bending deformation. The piezoelectric ceramic 33 is configured as a disc-shaped structure. In the radial direction of the vibrating plate 31, the first through hole 312 is located outside the outer contour of the piezoelectric ceramic 33, so that the piezoelectric ceramic 33 directly avoids the first through hole 312. Therefore, it is not necessary to set avoidance holes or avoidance grooves on the piezoelectric ceramic 33, which effectively simplifies the processing steps of the piezoelectric ceramic 33 and reduces the processing difficulty and production cost.

[0036] According to one embodiment of this application, the annular groove 311 is provided with a plurality of first through holes 312, and the plurality of first through holes 312 are arranged in annular array on the outer periphery of the piezoelectric ceramic 33.

[0037] In this embodiment, the gas flow cross-sectional area can be increased by setting multiple first through holes 312, thereby increasing the overall gas flow rate of the piezoelectric pump. The multiple first through holes 312 are located on the outer periphery of the piezoelectric ceramic 33, so that the piezoelectric ceramic 33 does not need to be provided with an avoidance structure, thereby maximizing its effective vibration area. This can balance the proportion of the overall volume of the piezoelectric pump and the vibration area of ​​the piezoelectric ceramic 33, achieving synergistic optimization of small volume and high pumping performance.

[0038] In some specific embodiments of this application, the depth of the annular groove 311 is 10% to 40% of the thickness of the vibrating plate 31.

[0039] If the depth of the annular groove 311 is too small, on the one hand, the effective volume of the working cavity enclosed by the annular groove 311 will be too small, and on the other hand, the structural differentiation between the vibration zone and the fixed zone will be weak, the vibration deformation amplitude of the vibration zone will be limited, and the pressure change in the working cavity will be insufficient, resulting in insufficient pumping capacity. If the depth of the annular groove 311 is too large, it will affect the structural strength of the vibrating plate 31. Under long-term high-frequency vibration, the vibrating plate 31 is prone to deformation fatigue, cracking and other problems, shortening the service life of the product.

[0040] In this embodiment, the depth of the annular groove 311 is controlled within 10% to 40% of the thickness of the vibrating plate 31, such as 10%, 20%, 30%, 40%, etc. This allows the annular groove 311 to form a sufficiently large working cavity, clearly dividing the fixed area and the vibration area of ​​the vibrating plate 31, so that the vibration area can obtain sufficient vibration deformation amplitude, thereby ensuring that the working cavity generates intense and controllable pressure fluctuations and achieves efficient gas delivery. At the same time, it retains sufficient base wall thickness of the vibrating plate 31 to maintain the overall structural rigidity of the vibrating plate 31, thereby avoiding fatigue cracking at the groove position and taking into account both the pumping performance of the piezoelectric pump and the long-term working reliability.

[0041] According to one embodiment of this application, the diameter of the first through hole 312 is 2% to 10% of the diameter of the vibrating plate 31.

[0042] If the diameter of the first through hole 312 is too small, it will lead to high gas flow resistance, poor exhaust from the working chamber, and reduced pumping efficiency. If the diameter of the first through hole 312 is too large, it will lead to insufficient effective bearing area in the annular groove 311 region, weakening the structural strength of the vibration zone and easily causing vibration deformation instability or fatigue damage. In this embodiment, the diameter of the first through hole 312 is limited to 2% to 10% of the diameter of the vibrating plate 31, such as 2%, 4%, 6%, 8%, 10%, etc. Within this range, it can ensure sufficient gas flow cross-sectional area, reduce flow resistance, ensure smooth exhaust from the working chamber, and maintain efficient pumping; at the same time, it can retain sufficient effective bearing area at the bottom of the annular groove 311 to ensure the structural strength and vibration stability of the vibration zone.

[0043] In some specific embodiments of this application, the piezoelectric pump further includes: a flexible circuit board 40 and a washer 50, wherein the flexible circuit board 40 and the washer 50 are clamped and fixed between the cover plate 10 and the vibrating plate 31; the washer 50 is located between the vibrating plate 31 and the flexible circuit board 40, and the flexible circuit board 40 is electrically connected to the piezoelectric ceramic 33.

[0044] In other words, a flexible circuit board 40 and a washer 50 are sandwiched and fixed between the fixed area and the cover plate 10. The flexible circuit board 40 is electrically connected to the piezoelectric ceramic 33 to supply power to the piezoelectric ceramic 33; the washer 50 is located on the side of the flexible circuit board 40 closer to the fixed area; relying on the thickness of the washer 50 itself to form a raised structure in the thickness direction of the vibrating plate 31, the flexible circuit board 40 can be raised to a position higher than the surface of the piezoelectric ceramic 33, which can effectively prevent the flexible circuit board 40 from affecting the vibration of the piezoelectric ceramic 33 and the vibrating plate, and at the same time facilitates the electrical connection with the piezoelectric ceramic 33.

[0045] According to one embodiment of this application, the sidewall of the fixed area is provided with a protrusion 313, the protrusion 313 is electrically connected to the side of the piezoelectric ceramic 33 near the vibrating plate 31, and the flexible circuit board 40 is electrically connected to the side of the piezoelectric ceramic 33 away from the vibrating plate 31.

[0046] Specifically, the vibrating plate 31 can be configured as a metal plate, and the side wall of the fixed area is provided with a protrusion 313 extending radially therein. The piezoelectric ceramic 33 is provided with a first electrode 331 on the side near the vibrating plate 31, and a second electrode 332 on the side away from the vibrating plate 31. The first electrode 331 contacts the vibrating plate 31, so that the protrusion 313 and the side of the piezoelectric ceramic 33 near the vibrating plate 31 are electrically connected. The flexible circuit board 40 is electrically connected to the second electrode 332 of the piezoelectric ceramic 33, so that the flexible circuit board 40 and the side of the piezoelectric ceramic 33 away from the vibrating plate 31 are electrically connected.

[0047] In this embodiment, the first electrode 331 and the second electrode 332 do not need to be placed on the same side of the piezoelectric ceramic 33, which can simplify the electrode layout structure of the piezoelectric ceramic 33 and reduce the difficulty of electrode processing.

[0048] In some specific embodiments of this application, the piezoelectric ceramic 33 is provided with a first electrode 331 and a second electrode 332 on the side near the vibrating plate 31. The piezoelectric pump further includes a flexible circuit board 40, which is clamped and fixed between the piezoelectric ceramic 33 and the vibrating plate 31. The first electrode 331 and the second electrode 332 are electrically connected to the flexible circuit board 40, respectively.

[0049] Specifically, such as Figure 3 and Figure 4 As shown, the piezoelectric ceramic 33 has a first electrode 331 and a second electrode 332 on the side near the vibrating plate 31. The first electrode 331 is electrically connected to the side of the piezoelectric ceramic 33 near the vibrating plate 31, and the second electrode 332 is electrically connected to the side of the piezoelectric ceramic 33 away from the vibrating plate 31. A flexible circuit board 40 is sandwiched and fixed between the piezoelectric ceramic 33 and the vibrating plate 31. Both the first electrode 331 and the second electrode 332 are electrically connected to the flexible circuit board 40, so that power can be supplied to the piezoelectric ceramic 33 through the flexible circuit board 40.

[0050] In this embodiment, the flexible circuit board 40 is located between the vibrating plate 31 and the piezoelectric ceramic 33, eliminating the need for the gasket 50 structure. This effectively reduces the number of assembly parts, lowers assembly difficulty and production costs, and eliminates the thickness occupied by the gasket 50, thereby reducing the axial stacking size of the pump body and achieving a reduction in the overall thickness.

[0051] According to one embodiment of this application, the flexible circuit board 40 is bonded and fixed between the piezoelectric ceramic 33 and the vibrating plate 31.

[0052] In this embodiment, the flexible circuit board 40 can be bonded to the piezoelectric ceramic 33 and the vibrating plate 31 with adhesive, which can ensure the sealing of the connection. Moreover, the assembly process is simple, easy to mass-produce, and has high assembly efficiency.

[0053] In some optional examples of this application, the air outlet 11 is provided with a first one-way valve, and the air inlet 21 is provided with a second one-way valve. The first one-way valve is used to allow gas to flow out of the air outlet in one direction, and the air inlet is used to allow gas to flow in from the air inlet in one direction.

[0054] In this example, the piezoelectric pump can achieve unidirectional gas delivery through the coordinated operation of the first and second check valves.

[0055] According to one embodiment of this application, the spring piece 32 is bonded between the fixing area and the base 20.

[0056] In this embodiment, the spring piece 32 can be glued between the fixing area and the base 20 to ensure the sealing of the connection. At the same time, the adhesive layer formed by the glue creates a preset gap between the protrusion and the spring piece 32, eliminating the need for additional limiting structures, thereby simplifying the assembly process and reducing manufacturing costs.

[0057] In some specific embodiments of this application, the distance between the protrusion and the spring piece 32 is 5μm-20μm.

[0058] If the distance between the protrusion and the spring is too small, it will affect the vibration of the vibrating plate 31 and the spring 32; if the distance between the protrusion and the spring 32 is too large, it will be impossible to directly achieve unidirectional gas flow. In this embodiment, the distance between the protrusion and the spring 32 is configured to be 5μm-20μm, such as 5μm, 8μm, 10μm, 12μm, 14μm, 16μm, 18μm, 20μm. This can ensure the normal vibration of the vibrating plate and the spring while creating a significant flow resistance difference between the air inlet passage and the air outlet passage, thereby driving the gas to flow unidirectionally from the air inlet 21 to the air outlet 11 without the need for an additional one-way valve structure.

[0059] In this example, the spring 32 and the vibrating plate 31 are bonded together with glue. By controlling the thickness of the glue coating, the distance between the protrusion and the spring 32 can be kept in the range of 5μm-20μm.

[0060] In summary, according to the piezoelectric pump provided in this embodiment, by creating an annular groove 311 in the vibrating plate 31, the vibrating plate 31 is integrally divided into a fixed area and a vibration area. The vibrating plate 31, along with the spring sheet 32, is clamped and assembled between the base 20 and the cover plate 10 using its own fixed area. No additional connecting layer is required, simplifying the overall structural hierarchy and freeing up internal assembly space for the piezoelectric pump. While maintaining the same pumping flow rate and pressure performance, the overall size of the piezoelectric pump can be reduced, achieving a miniaturized design while ensuring sufficient pumping capacity. Furthermore, the vibrating plate 31 can form a near-edge-fixed vibration mode at the operating frequency. This vibration mode is a knotless circular mode, concentrating vibration energy in the vibration area, reducing energy loss at the boundary, improving overall vibration response efficiency, and making the pressure change in the working chamber more dramatic and controllable, effectively improving overall pumping efficiency.

[0061] Embodiments of this application also provide an electronic device including the piezoelectric pump described in any of the above embodiments. Since the piezoelectric pump according to the embodiments of this application has the above-described technical effects, the electronic device according to the embodiments of this application also has corresponding technical effects, which will not be repeated in this embodiment.

[0062] While specific embodiments of this application have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of this application. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of this application. The scope of this application is defined by the appended claims.

Claims

1. A piezoelectric pump, characterized in that, include: Cover plate (10), the cover plate (10) is provided with an air outlet (11); The base (20) is provided with an air inlet (21), the cover plate (10) and the base (20) enclose a cavity to form a receiving cavity, and the air outlet (11) and the air inlet (21) are both connected to the receiving cavity; Vibration assembly (30) includes a vibrating plate (31) and a spring plate (32). The first side of the vibrating plate (31) faces the base (20). The first side of the vibrating plate (31) is provided with an annular groove (311). The annular groove (311) is provided with a first through hole (312). The spring plate (32) is located on the first side of the vibrating plate (31). The spring plate (32) is provided with a second through hole (321). The vibrating plate (31) forms a fixed area outside the outer contour of the annular groove (311), and the spring piece (32) is clamped and fixed between the cover plate (10) and the base (20) and the vibrating plate (31). The vibrating plate (31) forms a protrusion in the area within the inner contour of the annular groove (311), and there is a gap between the protrusion and the spring piece (32).

2. The piezoelectric pump according to claim 1, characterized in that, The vibration assembly (30) also includes: The piezoelectric ceramic (33) is disposed on the second side of the vibrating plate (31), and the first through hole (312) is located outside the outer contour of the piezoelectric ceramic (33).

3. The piezoelectric pump according to claim 2, characterized in that, The annular groove (311) is provided with a plurality of first through holes (312), and the plurality of first through holes (312) are arranged in annular array on the outer periphery of the piezoelectric ceramic (33).

4. The piezoelectric pump according to claim 1, characterized in that, The depth of the annular groove (311) is 10% to 40% of the thickness of the vibrating plate (31).

5. The piezoelectric pump according to claim 1, characterized in that, The diameter of the first through hole (312) is 2% to 10% of the diameter of the vibrating plate (31).

6. The piezoelectric pump according to claim 2, characterized in that, The piezoelectric pump also includes: A flexible circuit board (40) and a gasket (50) are clamped and fixed between the cover plate (10) and the vibrating plate (31). The washer (50) is located between the vibrating plate (31) and the flexible circuit board (40), and the flexible circuit board (40) is electrically connected to the piezoelectric ceramic (33).

7. The piezoelectric pump according to claim 6, characterized in that, The side wall of the fixed area is provided with a protrusion (313), the protrusion (313) is electrically connected to the side of the piezoelectric ceramic (33) near the vibrating plate (31), and the flexible circuit board (40) is electrically connected to the side of the piezoelectric ceramic (33) away from the vibrating plate (31).

8. The piezoelectric pump according to claim 2, characterized in that, The piezoelectric ceramic (33) has a first electrode (331) and a second electrode (332) on the side near the vibrating plate (31), and the piezoelectric pump further includes: A flexible circuit board (40) is clamped and fixed between the piezoelectric ceramic (33) and the vibrating plate (31), and the first electrode (331) and the second electrode (332) are electrically connected to the flexible circuit board (40) respectively.

9. The piezoelectric pump according to claim 8, characterized in that, The flexible circuit board (40) is bonded and fixed between the piezoelectric ceramic (33) and the vibrating plate (31).

10. The piezoelectric pump according to claim 1, characterized in that, The spring piece (32) is bonded between the fixing area and the base (20); and / or, the distance between the protrusion and the spring piece (32) is 5μm-20μm.

11. An electronic device, characterized in that, Includes the piezoelectric pump according to any one of claims 1-10.

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