Vibration plate for piezoelectric micropump and piezoelectric micropump thereof

Abstract

The present invention relates to the technical field of piezoelectric micropumps, and in particular to a vibration plate for a piezoelectric micropump. In addition, the present invention also relates to a piezoelectric micropump comprising the vibration plate for a piezoelectric micropump, wherein the vibration plate comprises a vibration portion and a connection portion arranged at the periphery of the vibration portion; the connection portion is penetrated by at least one window, and a connection cantilever for fixed connection with a piezoelectric vibrator is provided in the window, and the connection cantilever comprises a beam portion and at least one cantilever portion. The present invention connects the connection cantilever between the beam portion and the window in a manner that it is approximately oriented toward or completely oriented toward the center of the vibration portion. On the one hand, the connection portion except the window can be fixedly connected to a support plate, which greatly improves the connection area between the vibration plate as a key component and the support plate, increases the connection strength, and reduces the risk of connection failure during operation. On the other hand, the torsion of the connection cantilever when it is bent can be reduced, thereby improving the service life.

Description

Technical Field

[0001] The present invention relates to the technical field of piezoelectric micropumps, in particular to a vibration plate for a piezoelectric micropump. In addition, the present invention also relates to a piezoelectric micropump comprising the vibration plate for a piezoelectric micropump. Background Art

[0002] Piezoelectrically driven fluid delivery and control devices have the advantages of compact structure, easy miniaturization, easy integration, high control accuracy, fast response speed, low power consumption, long life, and high reliability. They have wide application needs in the fields of medicine, biology, and chemical industry.

[0003] In this regard, some piezoelectric micro pumps have appeared in the prior art, such as patent document CN109869302A, a vertically supported micro piezoelectric pump, in which the beam portion in the flexible plate (vibration plate) is arranged circumferentially, resulting in the beam portion being prone to torsional deformation when bending with the actuator (piezoelectric vibrator), and thus causing the root of the beam portion to be prone to fracture;

[0004] Patent document CN 111980887 A discloses a staggered support structure and a gas control device for a piezoelectric micropump, in which the cantilever in the resonance plate (vibration plate) is radially arranged. Although it can greatly reduce torsional deformation when the beam portion bends with the piezoelectric vibrator, the resonance plate is connected to the support plate or the connecting plate through a protrusion, the connection area is small, the connection strength is not high, and there is a risk of connection failure. Summary of the invention

[0005] The technical problem to be solved by the present invention is: in order to solve the problem that the vibration plate in the piezoelectric micropump in the prior art cannot simultaneously reduce the torsional deformation of the beam part and have a larger effective connection area, a vibration plate for a piezoelectric micropump is provided. In addition, the present invention provides a piezoelectric micropump including the above-mentioned vibration plate for a piezoelectric micropump.

[0006] The technical solution adopted by the present invention to solve the technical problem is: a vibration plate for a piezoelectric micro pump, the piezoelectric micro pump has a piezoelectric vibrator, the vibration plate is used to cooperate with the piezoelectric vibrator, the vibration plate includes a vibration part and a connecting part arranged on the periphery of the vibration part, and the vibration part is penetrated by a flow hole;

[0007] At least one window is passed through the connecting portion, and a connecting cantilever is provided in the window for fixedly connecting to the piezoelectric vibrator. The connecting cantilever includes a beam portion and at least one cantilever portion. One end of the cantilever portion is fixedly connected to the radial side wall of the vibration portion in the window, and the other end is fixedly connected to the radial side wall of the vibration portion. Both ends of the beam portion in the circumferential direction of the vibration portion are suspended.

[0008] In this solution, a window is opened at the connecting part of the vibration plate, and a connecting cantilever is arranged in the window. The vibration plate is fixedly connected to the piezoelectric vibrator through the connecting cantilever, and the connecting part except the window can be fixedly connected to the support plate, which greatly improves the connection area between the vibration plate and the support plate as key components, increases the connection strength, and reduces the risk of connection failure during operation; at the same time, the cantilever part of the connecting cantilever is connected between the beam part and the window in a manner that is roughly toward or completely toward the center of the vibration part, thereby reducing the torsion of the connecting cantilever when it is bent and improving its service life.

[0009] The specific configuration schemes of the connecting cantilever of the present invention can be roughly divided into the following three types:

[0010] The first type is that the two side walls of the window in the radial direction of the vibration part are respectively a first radial inner wall and a second radial inner wall, and in the radial direction of the vibration part, the first radial inner wall is located outside the second radial inner wall; the two side walls of the beam part in the radial direction of the vibration part are respectively a first radial outer wall and a second radial outer wall, and in the radial direction of the vibration part, the first radial outer wall is located outside the second radial outer wall;

[0011] One end of the cantilever portion is fixedly connected to the first radial inner wall, and the other end of the cantilever portion is fixedly connected to the first radial outer wall.

[0012] The second type is that the two side walls of the window in the radial direction of the vibration part are respectively a first radial inner wall and a second radial inner wall, and in the radial direction of the vibration part, the first radial inner wall is located outside the second radial inner wall; the two side walls of the beam part in the radial direction of the vibration part are respectively a first radial outer wall and a second radial outer wall, and in the radial direction of the vibration part, the first radial outer wall is located outside the second radial outer wall;

[0013] One end of the cantilever portion is fixedly connected to the second radial inner wall, and the other end of the cantilever portion is fixedly connected to the second radial outer wall.

[0014] The third type is that the two side walls of the window in the radial direction of the vibration part are respectively a first radial inner wall and a second radial inner wall, and in the radial direction of the vibration part, the first radial inner wall is located outside the second radial inner wall; the two side walls of the beam part in the radial direction of the vibration part are respectively a first radial outer wall and a second radial outer wall, and in the radial direction of the vibration part, the first radial outer wall is located outside the second radial outer wall;

[0015] There is at least one cantilever portion between the first radial inner wall and the first radial outer wall, the cantilever portion between the first radial inner wall and the first radial outer wall is an outer cantilever, one end of the outer cantilever is fixedly connected to the first radial inner wall, and the other end is fixedly connected to the first radial outer wall;

[0016] There is at least one cantilever portion between the second radial inner wall and the second radial outer wall. The cantilever portion between the second radial inner wall and the second radial outer wall is an inner cantilever portion. One end of the inner cantilever portion is fixedly connected to the second radial inner wall, and the other end is fixedly connected to the second radial outer wall.

[0017] Furthermore, the inner cantilever portion and the outer cantilever portion correspond to each other one by one, and the outer cantilever portion and the corresponding inner cantilever portion are located in the same radial direction of the vibration portion.

[0018] Further, the cantilever portion is located in the radial direction of the vibration portion.

[0019] Furthermore, the connecting part and the vibrating part are integrally formed, or the connecting part and the vibrating part are fixedly connected.

[0020] Furthermore, the vibration plate is a conductor.

[0021] Furthermore, the connecting portion is a conductor.

[0022] Furthermore, the connecting cantilever and the connecting portion are integrally formed, or the connecting cantilever and the connecting portion are fixedly connected.

[0023] Furthermore, a second external electrode is provided on the outer edge of the connecting portion.

[0024] The present invention also provides a piezoelectric micropump, comprising a pump housing, a piezoelectric vibrator and a supporting structure, wherein an accommodating cavity is constructed between the pump housing and the supporting structure, the supporting structure comprising a supporting plate and a vibration plate arranged on the supporting plate, the vibration plate and the piezoelectric vibrator are both located in the accommodating cavity, the vibration plate is the above-mentioned vibration plate for the piezoelectric micropump, the support plate is fixedly connected to the connecting portion of the vibration plate on the side facing the accommodating cavity, a recessed groove is provided on the side of the support plate facing the vibration plate, the recessed groove is opposite to the vibration portion, and cooperates with the vibration plate to form a drainage cavity, an air inlet hole connected to the drainage cavity is provided on the support plate, the connecting cantilever is fixedly connected to the piezoelectric vibrator, and a avoidance groove corresponding to the position of the connecting cantilever is provided on the side of the support plate 4 facing the vibration plate 3.

[0025] Furthermore, the peripheral edge of the connecting portion of the vibration plate is clamped between the pump housing and the support plate.

[0026] The beneficial effects of the present invention are as follows: the vibration plate used for the piezoelectric micropump of the present invention connects the connecting cantilever between the beam portion and the window in a manner that the connecting cantilever is roughly or completely oriented toward the center of the vibration portion. On the one hand, the connecting portion except the window can be fixedly connected to the support plate, which greatly improves the connection area between the vibration plate and the support plate as key components, increases the connection strength, and reduces the risk of connection failure during operation. On the other hand, it can reduce the torsion of the connecting cantilever when it is bent, thereby improving the service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0028] Figure 1 is a schematic diagram of a vibration plate used for a piezoelectric micropump in Example 1 of the present invention;

[0029] Figure 2 is a schematic diagram of a vibration plate used for a piezoelectric micropump in Embodiment 1 of the present invention being arranged in a piezoelectric micropump;

[0030] Figure 3 is a schematic diagram of a vibration plate used for a piezoelectric micropump in Example 2 of the present invention;

[0031] Figure 4 is a schematic diagram of a vibration plate used for a piezoelectric micropump in Embodiment 2 of the present invention being arranged in a piezoelectric micropump;

[0032] Figure 5 is a schematic diagram of a vibration plate for a piezoelectric micropump in Example 3 of the present invention;

[0033] Figure 6 is a schematic diagram of another vibration plate for a piezoelectric micropump in Example 3 of the present invention;

[0034] Figure 7 Schematic diagram of the air intake process of the piezoelectric micropump in Embodiment 4 of the present invention;

[0035] Figure 8 Schematic diagram of the gas outlet process of the piezoelectric micropump in Embodiment 4 of the present invention;

[0036] In the figure: 1, pump housing, 11, cover plate, 111, air outlet, 12, first partition plate, 13, electrode plate, 131, first external electrode, 14, second partition plate;

[0037] 2. piezoelectric vibrator, 21. substrate, 211. connecting boss, 22. piezoelectric element;

[0038] 3. a vibration plate, 31. a vibration portion, 311. a flow hole, 32. a connecting portion, 321. a window, 321a. a first radial inner wall, 321b. a second radial inner wall, 322. a connecting cantilever, 3221. a beam portion, 3221a. a first radial outer wall, 3221b. a second radial outer wall, 3222. a cantilever portion, 323. a second external electrode;

[0039] 4. support plate, 41. recessed groove, 42. avoidance groove, 43. air inlet;

[0040] 5. Accommodating cavity;

[0041] 6. Drainage cavity. DETAILED DESCRIPTION

[0042] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams that only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention, and directions and references (e.g., up, down, left, right, etc.) may only be used to help describe the features in the drawings. Therefore, the following specific embodiments are not to be taken in a limiting sense, and the scope of the subject matter claimed is limited only by the attached claims and their equivalents.

[0043] Example 1

[0044] like Figure 1 and 2 As shown, a vibration plate for a piezoelectric micro pump, the piezoelectric micro pump has a piezoelectric vibrator 2, the vibration plate 3 is used to cooperate with the piezoelectric vibrator 2, the vibration plate 3 includes a vibration part 31 and a connecting part 32 arranged on the periphery of the vibration part 31, and the vibration part 31 is penetrated by a flow hole 311;

[0045] The connecting portion 32 is penetrated by at least one window 321, and the window 321 has a connecting cantilever 322 for fixedly connecting to the piezoelectric vibrator 2. The connecting cantilever 322 includes a beam portion 3221 and at least one cantilever portion 3222. One end of the cantilever portion 3222 is fixedly connected to the radial side wall of the vibration portion 31 in the window 321, and the other end is fixedly connected to the radial side wall of the vibration portion 31 of the beam portion 3221. The beam portion 3221 is suspended at both ends of the vibration portion 31 in the circumferential direction.

[0046] When the connection portion 32 has a plurality of windows 321 , preferably, the plurality of windows 321 are evenly distributed along the circumference of the vibration portion 31 .

[0047] The connecting portion 32 and the vibrating portion 31 are integrally formed, or the connecting portion 32 and the vibrating portion 31 are fixedly connected.

[0048] The vibration plate 3 is a conductor as a whole, or only the connection part 32 on the vibration plate 3 is a conductor; thus, it can serve as one pole of the piezoelectric vibrator 2 and be electrically connected to the piezoelectric vibrator 2, and there is no need to additionally provide an electrode plate for the piezoelectric vibrator 2, making the overall structure more compact. At the same time, the vibration plate 3 is fixedly connected to the piezoelectric vibrator 2, and it is easy to achieve electrical connection, thereby bringing convenience to the power supply of the piezoelectric micropump. Compared with the prior art, there is no need to flanging the piezoelectric element 22, which reduces the manufacturing cost, reduces the area of ​​the electrical connection region on the piezoelectric element 22, and reduces the influence of the bending deformation of the piezoelectric element 22 under the action of the electrical signal.

[0049] It is worth noting that in this embodiment, the connecting cantilever 322 can be fixedly disposed on the connecting portion 32, or can be integrally formed with the connecting portion 32. When integrally formed, it is beneficial to reduce the process difficulty, reduce the manufacturing cost, and improve reliability.

[0050] Preferably, the recessed groove 41 , the vibrating portion 31 , the flow hole 311 on the vibrating portion 31 and the piezoelectric vibrator 2 are coaxially arranged.

[0051] A second external electrode 323 is disposed on the outer edge of the connecting portion 32 . Preferably, the second external electrode 323 and the connecting portion 32 are formed integrally.

[0052] The two side walls of the window 321 in the radial direction of the vibration part 31 are respectively the first radial inner wall 321a and the second radial inner wall 321b, and in the radial direction of the vibration part 31, the first radial inner wall 321a is located on the outside of the second radial inner wall 321b; the two side walls of the beam part 3221 in the radial direction of the vibration part 31 are respectively the first radial outer wall 3221a and the second radial outer wall 3221b, and in the radial direction of the vibration part 31, the first radial outer wall 3221a is located on the outside of the second radial outer wall 3221b; one end of the cantilever part 3222 is fixedly connected to the first radial inner wall 321a, and the other end is fixedly connected to the first radial outer wall 3221a.

[0053] The cantilever portion 3222 is located in the radial direction of the vibration portion 31 .

[0054] In this embodiment, a window 321 is opened on the connecting portion 32 of the vibration plate 3, and a connecting cantilever 322 is arranged in the window 321. The vibration plate 3 is fixedly connected to the piezoelectric vibrator 2 through the connecting cantilever 322, and the portion of the connecting portion 32 except the window 321 can be fixedly connected to the support plate 4, which greatly improves the connection area between the vibration plate 3 and the support plate 4 as key components, increases the connection strength, and reduces the risk of connection failure during operation; at the same time, the cantilever portion 3222 of the connecting cantilever 322 is connected between the beam portion 3221 and the window 321 in a manner of roughly or completely facing the center of the vibration portion 31, thereby reducing the torsion of the connecting cantilever 322 when bending, thereby improving the service life.

[0055] Example 2

[0056] like Figure 3 and 4As shown, the difference between Example 2 and Example 1 lies in that: the two side walls of the window 321 in the radial direction of the vibration part 31 are respectively the first radial inner wall 321a and the second radial inner wall 321b, and in the radial direction of the vibration part 31, the first radial inner wall 321a is located on the outside of the second radial inner wall 321b; the two side walls of the beam portion 3221 in the radial direction of the vibration part 31 are respectively the first radial outer wall 3221a and the second radial outer wall 3221b, and in the radial direction of the vibration part 31, the first radial outer wall 3221a is located on the outside of the second radial outer wall 3221b; one end of the cantilever portion 3222 is fixedly connected to the second radial inner wall 321b, and the other end is fixedly connected to the second radial outer wall 3221b.

[0057] In this embodiment, a window 321 is opened on the connecting portion 32 of the vibration plate 3, and a connecting cantilever 322 is arranged in the window 321. The vibration plate 3 is fixedly connected to the piezoelectric vibrator 2 through the connecting cantilever 322, and the portion of the connecting portion 32 except the window 321 can be fixedly connected to the support plate 4, which greatly improves the connection area between the vibration plate 3 and the support plate 4 as key components, increases the connection strength, and reduces the risk of connection failure during operation; at the same time, the cantilever portion 3222 of the connecting cantilever 322 is connected between the beam portion 3221 and the window 321 in a manner of roughly or completely facing the center of the vibration portion 31, thereby reducing the torsion of the connecting cantilever 322 when bending, thereby improving the service life.

[0058] Example 3

[0059] like Figure 5 As shown, the difference between Example 3 and Example 1 is that: the two side walls of the window 321 in the radial direction of the vibration part 31 are respectively a first radial inner wall 321a and a second radial inner wall 321b, and in the radial direction of the vibration part 31, the first radial inner wall 321a is located on the outside of the second radial inner wall 321b; the two side walls of the beam part 3221 in the radial direction of the vibration part 31 are respectively a first radial outer wall 3221a and a second radial outer wall 3221b, and in the radial direction of the vibration part 31, the first radial outer wall 3221a is located on the outside of the second radial outer wall 3221b;

[0060] At least one cantilever portion 3222 is provided between the first radial inner wall 321a and the first radial outer wall 3221a. The cantilever portion 3222 between the first radial inner wall 321a and the first radial outer wall 221a is an outer cantilever, one end of the outer cantilever is fixedly connected to the first radial inner wall 321a, and the other end is fixedly connected to the first radial outer wall 3221a.

[0061] There is at least one cantilever portion 3222 between the second radial inner wall 321b and the second radial outer wall 3221b. The cantilever portion 3222 between the second radial inner wall 321b and the second radial outer wall 3221b is an inner cantilever portion, one end of the inner cantilever portion is fixedly connected to the second radial inner wall 321b, and the other end is fixedly connected to the second radial outer wall 3221b.

[0062] It is worth noting that in this embodiment, the number of the inner cantilever parts and the outer cantilever parts can be the same or different; wherein, when the number of the inner cantilever parts and the outer cantilever parts is the same, preferably, Figure 5 As shown, the inner cantilever portion and the outer cantilever portion correspond to each other, and the outer cantilever portion and the corresponding inner cantilever portion are located in the same radial direction of the vibration portion 31; it can also be, as shown in Figure 6 As shown, there are multiple inner cantilever parts and multiple outer cantilever parts, but the inner cantilever parts and the outer cantilever parts are not distributed in the same radial direction of the vibration part 31.

[0063] In this embodiment, a window 321 is opened on the connecting portion 32 of the vibration plate 3, and a connecting cantilever 322 is arranged in the window 321. The vibration plate 3 is fixedly connected to the piezoelectric vibrator 2 through the connecting cantilever 322, and the portion of the connecting portion 32 except the window 321 can be fixedly connected to the support plate 4, which greatly improves the connection area between the vibration plate 3 and the support plate 4 as key components, increases the connection strength, and reduces the risk of connection failure during operation; at the same time, the cantilever portion 3222 of the connecting cantilever 322 is connected between the beam portion 3221 and the window 321 in a manner of roughly or completely facing the center of the vibration portion 31, thereby reducing the torsion of the connecting cantilever 322 when bending, thereby improving the service life.

[0064] Example 4

[0065] like Figure 2 and 4 As shown, a piezoelectric micropump comprises a pump housing 1, a piezoelectric vibrator 2 and a supporting structure, a receiving cavity 5 is constructed between the pump housing 1 and the supporting structure, the supporting structure comprises a supporting plate 4 and a vibration plate 3 arranged on the supporting plate 4, the vibration plate 3 and the piezoelectric vibrator 2 are both located in the receiving cavity 5, the vibration plate 3 is the vibration plate for the piezoelectric micropump in Example 1, 2 or 3, the support plate 4 is fixedly connected to the connecting portion 32 of the vibration plate 3 on the side facing the receiving cavity 5, the support plate 4 is provided with a recessed groove 41 on the side facing the vibration plate 3, the recessed groove 41 is opposite to the vibration portion 31, and cooperates with the vibration plate 3 to form a drainage cavity 6, the support plate 4 is provided with an air inlet hole 43 connected to the drainage cavity 6, and the connecting cantilever 322 is fixedly connected to the piezoelectric vibrator 2.

[0066] Among them, the pump housing 1 includes a cover plate 11, a first partition plate 12, an electrode plate 13 and a second partition plate 14 which are sealed and connected in sequence from top to bottom. The cover plate 11 is provided with an air outlet 111 connected to the accommodating chamber 5. The first partition plate 12, the electrode plate 13 and the second partition plate 14 are all provided with through holes connected to the accommodating chamber 5. The electrode plate 13 is formed with a first external electrode 131 extending outside the accommodating chamber 5 and an internal electrode arranged in the accommodating chamber 5. The second partition plate 14 is an insulating plate, and the second partition plate 14 is sealed and connected to the supporting structure; the outer peripheral edge of the connecting portion 32 of the vibration plate 3 is clamped and fixed between the support plate 4 and the second partition plate 14.

[0067] The piezoelectric vibrator 2 includes a substrate 21 and one or more piezoelectric elements 22 arranged on a side of the substrate 21 away from the support structure. The shapes of the substrate 21 and the piezoelectric element 22 can be circular, square, polygonal or other shapes, which are not limited here. In this embodiment, the substrate 21 and the piezoelectric element 22 are both circular and coaxially arranged. The substrate 21 constituting the piezoelectric vibrator 2 is a conductor. The outer peripheral edge of the substrate 21 facing the vibration plate 3 has at least one connecting boss 211, and the connecting cantilever 322 corresponds to the connecting boss 211 one by one. The connecting cantilever 322 is fixedly connected to the corresponding connecting boss 211, and the side of the support plate 4 facing the vibration plate 3 is provided with an avoidance groove 42 corresponding to the position of the connecting cantilever 322.

[0068] The piezoelectric element 22 and the internal electrodes of the electrode plate 13 are electrically connected, the vibration plate 3 is electrically connected to the substrate 21, the substrate 21 is electrically connected to the piezoelectric element 22, and the second external electrode 323 on the vibration plate 3 is located outside the accommodating cavity 5. When an external power source applies an AC voltage to the piezoelectric vibrator 2 through the first external electrode 131 and the second external electrode 323, the piezoelectric vibrator 2 can produce reciprocating bending deformation. After the two poles of the piezoelectric vibrator 2 are loaded with AC voltage, reciprocating bending deformation can occur.

[0069] At a suitable operating frequency, the piezoelectric vibrator 2 and the vibration plate 3 reach a certain resonance state, that is, when a driving voltage is applied to the piezoelectric vibrator 2, the piezoelectric vibrator 2 bulges upward and bends and deforms. Figure 7 As shown in FIG. 1 , the gap between the piezoelectric vibrator 2 and the vibration plate 3 becomes larger near the center of the piezoelectric vibrator 2, where the flow resistance is smaller, and the gap between the piezoelectric vibrator 2 and the vibration plate 3 becomes smaller at the periphery of the piezoelectric vibrator 2, where the flow resistance is larger. Therefore, the fluid is mainly sucked in from the flow hole 311. When the piezoelectric vibrator 2 is bent and deformed downward, as shown in FIG. Figure 8As shown, the gap between the piezoelectric vibrator 2 and the vibration plate 3 becomes smaller near the center of the piezoelectric vibrator 2, where the flow resistance is larger, and the gap between the piezoelectric vibrator 2 and the vibration plate 3 is larger at the periphery of the piezoelectric vibrator 2, where the flow resistance is smaller. Therefore, the fluid mainly flows out from the periphery of the piezoelectric vibrator 2 to the air outlet 111. By controlling the alternating current, the above-mentioned suction and discharge processes are repeated to achieve the purpose of continuously conveying the fluid.

[0070] The above-mentioned ideal embodiments of the present invention are for inspiration. Through the above-mentioned description, relevant staff can make various changes and modifications without departing from the technical idea of ​​the present invention. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A vibration plate for a piezoelectric micropump, the piezoelectric micropump having a piezoelectric vibrator (2), the vibration plate (3) being used to cooperate with the piezoelectric vibrator (2), characterized in that: The vibration plate (3) comprises a vibration portion (31) and a connection portion (32) arranged on the periphery of the vibration portion (31), and a flow hole (311) penetrates through the vibration portion (31); At least one window (321) passes through the connecting portion (32), the window (321) has a connecting cantilever (322) for fixedly connecting to the piezoelectric vibrator (2), the connecting cantilever (322) comprising a beam portion (3221) and at least one cantilever portion (3222), one end of the cantilever portion (3222) being connected to a radial side wall of the vibration portion (31) in the window (321), and the other end being fixedly connected to a radial side wall of the beam portion (3221) of the vibration portion (31), and the two ends of the beam portion (3221) being suspended in the air in the circumferential direction of the vibration portion (31); The two side walls of the window (321) in the radial direction of the vibration part (31) are respectively a first radial inner wall (321a) and a second radial inner wall (321b); in the radial direction of the vibration part (31), the first radial inner wall (321a) is located outside the second radial inner wall (321b); the two side walls of the beam part (3221) in the radial direction of the vibration part (31) are respectively a first radial outer wall (3221a) and a second radial outer wall (3221b); in the radial direction of the vibration part (31), the first radial outer wall (3221a) is located outside the second radial outer wall (3221b); One end of the cantilever portion (3222) is fixedly connected to the first radial inner wall (321a), and the other end is fixedly connected to the first radial outer wall (3221a); ​​or, at least one cantilever portion (3222) is provided between the first radial inner wall (321a) and the first radial outer wall (3221a), and the cantilever portion (3222) between the first radial inner wall (321a) and the first radial outer wall (3221a) is an outer cantilever, and one end of the outer cantilever is fixedly connected to the first radial inner wall (321a). ) is fixedly connected, and the other end is fixedly connected to the first radial outer wall (3221a), at least one cantilever portion (3222) is provided between the second radial inner wall (321b) and the second radial outer wall (3221b), the cantilever portion (3222) between the second radial inner wall (321b) and the second radial outer wall (3221b) is an inner cantilever portion, one end of the inner cantilever portion is fixedly connected to the second radial inner wall (321b), and the other end is fixedly connected to the second radial outer wall (3221b); The connecting portion (32) and the vibrating portion (31) are integrally formed, or the connecting portion (32) and the vibrating portion (31) are fixedly connected; The connecting cantilever (322) and the connecting portion (32) are integrally formed, or the connecting cantilever (322) and the connecting portion (32) are fixedly connected; By applying a driving voltage to the piezoelectric vibrator (2), when the piezoelectric vibrator (2) is convexly bent and deformed upward, the gap between the piezoelectric vibrator (2) and the vibration plate (3) becomes larger near the center of the piezoelectric vibrator (2), and the gap between the piezoelectric vibrator (2) and the vibration plate (3) becomes smaller at the periphery of the piezoelectric vibrator (2); when the piezoelectric vibrator (2) is convexly bent and deformed downward, the gap between the piezoelectric vibrator (2) and the vibration plate (3) becomes smaller near the center of the piezoelectric vibrator (2), and the gap between the piezoelectric vibrator (2) and the vibration plate (3) becomes larger at the periphery of the piezoelectric vibrator (2).

2. The vibration plate for a piezoelectric micro pump according to claim 1, characterized in that: The inner cantilever portion and the outer cantilever portion correspond to each other one by one, and the outer cantilever portion and the inner cantilever portion corresponding thereto are located in the same radial direction of the vibration portion (31).

3. The vibration plate for a piezoelectric micro pump according to claim 1 or 2, characterized in that: The cantilever portion (3222) is located in the radial direction of the vibration portion (31).

4. The vibration plate for a piezoelectric micro pump according to claim 1, characterized in that: The vibration plate (3) is a conductor.

5. The vibration plate for a piezoelectric micro pump according to claim 1, characterized in that: The connecting portion (32) is a conductor.

6. The vibration plate for a piezoelectric micro pump according to claim 1, characterized in that: A second external electrode (323) is provided on the outer edge of the connecting portion (32).

7. A piezoelectric micro pump, comprising a pump housing (1), a piezoelectric vibrator (2) and a support structure, wherein a receiving cavity (5) is formed between the pump housing (1) and the support structure, the support structure comprising a support plate (4) and a vibration plate (3) disposed on the support plate (4), the vibration plate (3) and the piezoelectric vibrator (2) being both located in the receiving cavity (5), characterized in that: The vibration plate (3) is a vibration plate for a piezoelectric micropump according to any one of claims 1 to 6, the support plate (4) is fixedly connected to the connecting portion (32) of the vibration plate (3) on the side facing the accommodating cavity (5), the support plate (4) is provided with a recessed groove (41) on the side facing the vibration plate (3), the recessed groove (41) is opposite to the vibration portion (31), and cooperates with the vibration plate (3) to form a drainage cavity (6), the support plate (4) is provided with an air inlet hole (43) connected to the drainage cavity (6), the connecting cantilever (322) and the piezoelectric vibrator (2) are fixedly connected, and the support plate (4) is provided with an avoidance groove (42) corresponding to the position of the connecting cantilever (322) on the side facing the vibration plate (3).

8. The piezoelectric micropump according to claim 7, characterized in that: The outer peripheral edge of the connecting portion (32) of the vibration plate (3) is clamped between the pump housing (1) and the support plate (4).

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