Piezoelectric pump

Abstract

The invention relates to the technical field of fluid control devices, in particular to a piezoelectric pump which comprises a piezoelectric actuator, a flexible plate and a flow guide plate, and the flow guide plate is provided with a first area located in the middle and a second area connected to the periphery of the first area and arranged around the first area in the circumferential direction. The surface of the side, facing the flexible plate, of the first area is sunken to form a sunken part, the surface of the side, deviating from the flexible plate, of the second area is provided with a drainage hole which does not penetrate through the flow guide plate, one end of the drainage channel communicates with the drainage hole, and the other end of the drainage channel communicates with the sunken part. Or a flow guide channel is formed by the face-to-face matching of the flow collecting plate and the flow guide plate which form the flow guide plate, so that the flow guide channel which can cause the discontinuous structure is far away from the surface of one side, facing the flexible plate, of the flow guide plate or the flow collecting plate; distortion protrusions facing one side of the vibration plate are generated at the communication position of the drainage channel and the concave part due to the discontinuous structure, and therefore noise is restrained.

Description

Technical Field

[0001] The present invention relates to the technical field of fluid control devices, and in particular to a piezoelectric pump. Background Art

[0002] Prior art, such as the invention application with publication number CN102979705B, discloses a fluid control device, that is, a micro piezoelectric pump, in which the actuator formed by the piezoelectric sheet and the vibration plate is a piezoelectric actuator, a flexible plate is spaced apart on one side of the vibration plate, a vent is formed in the center of the flexible plate, a substrate is joined to the side of the flexible plate away from the vibration plate, and a cylindrical opening is formed in the center, and the flexible portion of the flexible plate is exposed toward the substrate side at the opening of the substrate. Due to the pressure change of the fluid generated by the vibration of the actuator, the flexible portion vibrates at a frequency substantially the same as that of the actuator, and the portion of the flexible plate that is located further outward than the flexible portion is a fixed portion fixed to the substrate. In addition, a cover plate is also joined to the side of the substrate away from the flexible plate, and the cover plate and the substrate constitute a flow guide structure of the fluid control device, and three suction holes are provided on the cover plate, and the suction holes are connected to the opening via a radial flow path formed on the substrate;

[0003] The above-mentioned flow guide structure avoids the vent hole in the center of the flexible plate from being directly exposed to the environment, and can suppress the pressure waves and synthetic jets generated by the vibration of the actuator and the movable part 111, thereby substantially increasing the output pressure and flow rate of the fluid control device; but it will cause the micro piezoelectric pump to easily generate sharp noise during use, affecting the user experience. Summary of the invention

[0004] The technical problem to be solved by the present invention is: in order to solve the problem that the fluid control device in the prior art is prone to generate sharp noise during use, a piezoelectric pump is now provided.

[0005] The technical solution adopted by the present invention to solve its technical problem is: a piezoelectric pump, including a piezoelectric actuator, a flexible plate and a guide plate, the piezoelectric actuator is provided with a flexible plate, the flexible plate has a flexible portion located in the middle part and a fixed portion connected to the outer periphery of the flexible portion and arranged around the circumference of the flexible portion, a gap is left between the flexible plate and the piezoelectric actuator to form a pump cavity, the flexible portion and the piezoelectric actuator are provided with vent holes opposite to each other, the flexible plate is connected to the piezoelectric actuator through the fixed portion, and the guide plate is arranged on a side surface of the flexible plate away from the piezoelectric actuator; when the piezoelectric actuator vibrates, the gas in the pump cavity produces pressure changes, thereby causing the flexible portion to vibrate;

[0006] The flow guide plate has a first region at the middle part and a second region connected to the outer periphery of the first region and arranged circumferentially around the first region. The first region is disposed opposite to the flexible part, and a concave part is formed by the surface of the first region facing the flexible plate being recessed. The second region is fixedly connected to the fixing part. A drainage hole that does not penetrate the flow guide plate is provided on the surface of the second region facing away from the flexible plate. At least one drainage channel is provided inside the flow guide plate. One end of at least one drainage channel communicates with the drainage hole, and the other end communicates with the concave part.

[0007] Further, the flow guide plate has a drainage plate and a confluence plate arranged in a stacked manner, and the confluence plate is disposed on the side close to the flexible plate;

[0008] The concave part extends from the surface of the confluence plate close to the flexible plate towards the drainage plate;

[0009] The drainage hole extends from the surface of the drainage plate facing away from the flexible plate towards the confluence plate;

[0010] A drainage channel is formed between the confluence plate and the drainage plate.

[0011] Specifically, the first drainage channel solution is as follows: A first opening is formed by penetrating the first region corresponding to the surface of the confluence plate facing the flexible plate, and the drainage plate covers the first opening to form the concave part;

[0012] At least one drainage hole penetrating the drainage plate is provided in the region of the drainage plate opposite to the second region. At least one drainage groove extending from the second region to the first region is provided on the surface of the drainage plate close to the confluence plate. The confluence plate covers the end of the drainage hole close to the flexible plate and covers the drainage groove to form a drainage channel.

[0013] Specifically, the second drainage channel solution is as follows: A first opening is formed by penetrating the first region corresponding to the surface of the confluence plate facing the flexible plate. At least one drainage groove extending from the second region to the first region is provided on the surface of the confluence plate facing away from the flexible plate. The drainage plate covers the first opening to form the concave part and covers the drainage groove to form a drainage channel;

[0014] At least one drainage hole penetrating the drainage plate is provided in the region of the drainage plate opposite to the second region, and the end of the drainage hole close to the flexible plate is disposed opposite to the drainage groove.

[0015] Specifically, the third drainage channel solution is as follows: A first opening is formed by penetrating the first region corresponding to the surface of the confluence plate facing the flexible plate. At least one first drainage groove extending from the second region to the first region is provided on the surface of the confluence plate facing away from the flexible plate;

[0016] At least one drainage hole penetrating the drainage plate is provided in the area of the drainage plate opposite to the second area, and at least one second drainage groove extending from the second area to the first area and facing the first drainage groove is provided on the surface of the drainage plate facing the confluence plate;

[0017] The drainage plate covers the first opening to form the recessed part, the end of the drainage hole close to the flexible plate is arranged opposite to the first drainage groove, and the first drainage groove and the second drainage groove cooperate to form a drainage channel.

[0018] Further, the drainage holes are arranged in one-to-one correspondence with the drainage channels, and the drainage holes and the corresponding drainage channels are communicated.

[0019] Further, there are a plurality of the drainage holes, and the plurality of drainage holes are evenly distributed in the circumferential direction of the recessed part in the second area of the drainage plate.

[0020] Further, the piezoelectric actuator includes a vibrating plate and a piezoelectric sheet, at least one piezoelectric sheet is bonded to one or both surfaces of the piezoelectric actuator in the thickness direction, and the piezoelectric sheet and the vibrating plate are bonded to form the piezoelectric actuator;

[0021] The piezoelectric actuator has a first main surface and a second main surface arranged oppositely in the thickness direction, and the flexible plate is provided on the first main surface or / and the second main surface of the piezoelectric actuator.

[0022] Further, at least one connecting boss protrudes from the surface of the vibrating plate facing the flexible plate, a notch is formed in the area of the fixing part opposite to the connecting boss, and an elastic supporting part is formed in the notch, and the connecting boss and the elastic supporting part opposite to it are fixedly connected.

[0023] Further, the vibrating plate has a vibrating part, an outer peripheral part and a connecting part, the vibrating part is arranged opposite to the flexible part, the outer peripheral part surrounds the periphery of the vibrating part with a gap therebetween, the connecting part is arranged in the gap and connects the vibrating part and the outer peripheral part, the connecting part elastically supports the vibrating part on the outer peripheral part, and the fixing part is bonded to the outer peripheral part of the vibrating plate.

[0024] The beneficial effects of the present invention are as follows: In the piezoelectric pump of the present invention, by arranging a drainage channel inside the diversion plate, or by forming a drainage channel by the surface-to-surface cooperation of the confluence plate and the drainage plate constituting the diversion plate, the drainage channel that causes structural discontinuity is far away from the surface of the diversion plate or the confluence plate facing the flexible plate, which can greatly reduce the distortion bulge towards the vibrating plate side generated due to the structural discontinuity at the connection between the drainage channel and the recessed part after bonding, thereby suppressing noise.

[0025] Other features and advantages of the present application will become clear from the following detailed description of exemplary embodiments of the present application with reference to the accompanying drawings. Description of the Drawings

[0026] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0027] Figure 1 is a cross-sectional schematic view of a fluid control device in the prior art;

[0028] Figure 2 is a three-dimensional schematic view of a fluid control device in the prior art;

[0029] Figure 3 is a cross-sectional schematic view of a flow guiding plate with an integral structure used in the piezoelectric pump in Embodiment 1;

[0030] Figure 4 is a cross-sectional schematic view of a flow guiding plate formed by laminating a manifold plate and a diversion plate used in the piezoelectric pump in Embodiment 1;

[0031] Figure 5 is a schematic exploded view of one side of a flow guiding plate formed by laminating a manifold plate and a diversion plate used in the piezoelectric pump in Embodiment 1;

[0032] Figure 6 is a schematic exploded view of the other side of a flow guiding plate formed by laminating a manifold plate and a diversion plate used in the piezoelectric pump in Embodiment 1;

[0033] Figure 7 is a cross-sectional schematic view of the piezoelectric pump in Embodiment 2;

[0034] Figure 8 is a cross-sectional schematic view of the piezoelectric pump in Embodiment 3;

[0035] Figure 9 is a cross-sectional schematic view of the piezoelectric pump in Embodiment 4;

[0036] Figure 10 is a three-dimensional schematic view of one side of the piezoelectric pump in Embodiment 4;

[0037] Figure 11 is a three-dimensional schematic view of the other side of the piezoelectric pump in Embodiment 4.

[0038] In the figures: 1. Piezoelectric actuator, 11. Vibration plate, 111. Connecting boss, 11-1. Vibration part, 11-2. Outer peripheral part, 11-3. Connecting part, 11-4. Gap, 12. Piezoelectric sheet;

[0039] 2. Flexible plate, 21. Flexible part, 211. Vent hole, 22. Fixed part, 221. Notch, 222. Elastic support part, 223. First avoidance hole;

[0040] 3. Pump chamber;

[0041] 4. guide plate, 41. first area, 42. second area, 43. recessed portion, 44. drainage channel, 45. drainage hole;

[0042] 5. a manifold, 51. a first opening, 52. a avoidance hole, 53. a second avoidance hole, 54. a first drainage groove;

[0043] 6. drainage plate, 61. second drainage groove, 62. drainage groove;

[0044] 7. Substrate, 71. Flow path, 72. Opening;

[0045] 8. Cover plate, 81. Suction hole. DETAILED DESCRIPTION

[0046] 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.

[0047] The invention application with publication number CN102979705B discloses a fluid control device, namely a micro piezoelectric pump, see Figure 1 and 2 The actuator formed by the piezoelectric sheet 12 and the vibration plate 11 is a piezoelectric actuator 1. A flexible plate 2 is arranged at intervals on one side of the vibration plate 11. A vent hole 211 is formed in the center of the flexible plate 2. The substrate 7 is joined to the side of the flexible plate 2 away from the vibration plate 11, and a cylindrical opening 72 is formed in the center. The flexible portion 21 of the flexible plate 2 is exposed toward the substrate 7 side at the opening 72 of the substrate 7. Due to the pressure change of the fluid generated by the vibration of the actuator 1, the flexible portion 21 vibrates at a frequency substantially the same as that of the actuator. The portion of the flexible plate 2 located further outside than the flexible portion 21 is a fixed portion 22 fixed to the substrate 7. In addition, a cover plate 8 is also joined to the side of the substrate 7 away from the flexible plate 2. The cover plate 8 and the substrate 7 constitute a flow guide structure of the fluid control device. The cover plate 8 is provided with three suction holes 81. The suction holes 81 are connected to the opening 72 via a radial flow path 71 formed on the substrate 7.

[0048] In this regard, the inventors have found that the fluid control device with the above structure is prone to collision and produces sharp noise because:

[0049] In the above structure, a plurality of radially arranged flow paths 71 communicating with the central opening 72 are provided on the substrate 7. Inevitably, a plurality of sharp inflection points are formed at the communicating positions, resulting in discontinuous circumferential structures of the opening 72. After the substrate 7 and the flexible plate 2 are adhesively bonded, due to the difference in the linear expansion coefficients of the two (usually, the linear expansion coefficient of the flexible plate 2 is selected to be smaller than that of the substrate 7 in this structure), the bonded body will generate a bending deformation toward the diaphragm 11 side. At the inflection points, due to the structural discontinuity, distortion will occur toward the diaphragm 11 side, forming abnormal protrusions. Furthermore, the part of the flexible plate 2 opposite to this area will be too close to the diaphragm 11, resulting in a collision between the diaphragm 11 and the above-mentioned part of the flexible plate 2 during the operation of the fluid control device, generating a sharp noise and affecting the user experience.

[0050] In view of the above problems, the inventor provides the following implementation solutions;

[0051] Embodiment 1

[0052] As Figures 3 - 6 shown, a piezoelectric pump, specifically a micro piezoelectric pump, has an overall laminated structure, including a piezoelectric actuator 1, a flexible plate 2, and a flow guide plate 4;

[0053] The piezoelectric actuator 1 includes a diaphragm 11 and a piezoelectric sheet 12. At least one piezoelectric sheet 12 is bonded to one or both surfaces of the piezoelectric actuator 1 in the thickness direction. The piezoelectric sheet 12 and the diaphragm 11 are bonded to form the piezoelectric actuator 1; the piezoelectric actuator 1 has a first main surface and a second main surface that are oppositely arranged in the thickness direction; the shapes of the diaphragm 11 and the piezoelectric sheet 12 bonded to the diaphragm 11 can be, but are not limited to, circular, square, rectangular, polygonal, elliptical, etc. In this embodiment, the diaphragm 11 and the piezoelectric sheet 12 bonded to the diaphragm 11 are both in the shape of a circular plate as an example.

[0054] The piezoelectric sheet 12 is bonded to one surface of the diaphragm 11 in the thickness direction. It can be that a single piezoelectric sheet 12 is bonded to one surface of the diaphragm 11 to form a single crystal actuator; or two piezoelectric sheets 12 are respectively bonded to both surfaces of the diaphragm 11 to form a bimorph actuator; or multiple piezoelectric sheets 12 are bonded to one or both surfaces of the diaphragm 11 to form a composite type actuator. In this embodiment, a single piezoelectric sheet 12 bonded to one surface of the diaphragm 11 is used for illustration, but not limited thereto. The piezoelectric sheet 12 causes the actuator to vibrate under the excitation of an external electrical signal.

[0055] A flexible plate 2 is provided on the first major surface or / and the second major surface of the piezoelectric actuator 1. That is, the flexible plate 2 is disposed on the side where the first major surface or / and the second major surface of the piezoelectric actuator 1 is located with a gap therebetween. The flexible plate 2 has a flexible portion 21 at the middle part and a fixing portion 22 connected to the outer periphery of the flexible portion 21 and disposed circumferentially around the flexible portion 21. The flexible portion 21 and the fixing portion 22 can be integrally formed. Equivalently, the fixing portion 22 is located at a position of the flexible plate 2 that is more outward than the flexible portion 21. The fixing portion 22 is substantially fixed, while the flexible portion 21 can generate forced vibration. Further, the flexible portion 21 is located in a region of the flexible plate 2 that faces the center or near the center of the vibrating plate 11. The gap between the flexible plate 2 and the piezoelectric actuator 1 forms a pump chamber 3. An air vent hole 211 is provided on the flexible portion 21 opposite to the piezoelectric actuator 1. The flexible plate 2 is joined to the vibrating plate 11 of the piezoelectric actuator 1 through the fixing portion 22. Specifically, the side of the flexible plate 2 close to the vibrating plate 11 forms the inner wall of the pump chamber 3. When the piezoelectric actuator 1 vibrates, the pressure of the gas in the pump chamber 3 changes, thereby causing the flexible portion 21 to vibrate.

[0056] In this application, the piezoelectric pump can be such that a single flexible plate 2 is disposed on either side of the piezoelectric actuator 1 with a gap 11-4 therebetween, forming a pump chamber 3 on one side, so that the piezoelectric pump of this application has the functional characteristics of one side. Or two flexible plates 2 can be respectively disposed on both sides of the piezoelectric actuator 1 with a gap 11-4 therebetween, forming pump chambers 3 on both sides, so that the piezoelectric pump of this application has the functional characteristics of both sides. For the sake of easy understanding, in this embodiment, a single flexible plate 2 is disposed on the surface of the vibrating plate 11 away from the piezoelectric sheet 12 with a gap therebetween for illustration. Similarly, this does not constitute a limitation to this application.

[0057] As Figure 6 shown, at least one connecting boss 111 protrudes from the surface of the vibrating plate 11 facing the flexible plate 2. The connecting boss 111 can be integrally formed with the vibrating plate 11. All the connecting bosses 111 can be evenly distributed in the circumferential direction on the surface of the vibrating plate 11 facing the flexible plate 2. In the region of the fixing portion 22 of the flexible plate 2 opposite to the connecting boss 111, there is a notch 221, and an elastic support portion 222 is formed in the notch 221. The elastic support portion 222 can be formed by, but is not limited to, a material-removing method (such as local etching or laser cutting). As Figure 3 and 4 shown, one end of the elastic support portion 222 is connected to the connecting boss 111, and the other end is connected to the fixing portion 22. The connecting boss 111 and the elastic support portion 222 opposite thereto are fixedly connected, thereby elastically supporting the vibrating plate 11 on the flexible plate 2 in such a way that there is a pump chamber 3 between them.

[0058] The piezoelectric actuator 1 generates high-frequency bending vibrations under the excitation of an electrical signal. Stress concentration will occur at the fixed connection between the connecting boss 111 and the elastic support portion 222, and the main stress type here is shear stress. If the connecting boss 111 and the elastic support portion 222 are connected through an adhesive layer, the connection will fail due to long-term shear stress, affecting the actuation performance of the piezoelectric actuator 1. Preferably, the connecting boss 111 is fixedly connected to the opposite elastic support portion 222 by welding. For example, laser welding can be used. Further, an adhesive layer can be first provided between the connecting boss 111 and the opposite elastic support portion 222 for preliminary connection and retention, and then the connecting boss 111 and the opposite elastic support portion 222 are fixedly connected by welding.

[0059] The flow guide plate 4 is arranged on the surface of the flexible plate 2 on the side facing away from the piezoelectric actuator 1;

[0060] The flow guide plate 4 has a first region 41 at the middle part and a second region 42 connected to the outer periphery of the first region 41 and arranged circumferentially around the first region 41. The first region 41 is arranged opposite to the flexible portion 21, and a recess 43 is formed by the first region 41 being recessed toward the surface of the flexible plate 2 on one side. The fixing portion 22 is engaged with the second region 42 for fixed connection. Drainage holes 45 that do not penetrate through the flow guide plate 4 are provided on the surface of the second region 42 facing away from the flexible plate 2. At least one drainage channel 44 extending from the second region 42 to the first region 41 is provided inside the flow guide plate 4. One end of the at least one drainage channel 44 is communicated with the drainage hole 45, and the other end is communicated with the recess 43, as Figure 3 shown.

[0061] Specifically, the flow guide plate 4 can be formed by laminating at least two plate-like structural layers. For example, the flow guide plate 4 has a drainage plate 6 and a confluence plate 5 arranged in a laminated manner, and the confluence plate 5 is arranged on the side close to the flexible plate 2; the recess 43 extends from the surface of the confluence plate 5 on the side close to the flexible plate 2 toward the drainage plate 6; the drainage holes 45 extend from the surface of the drainage plate 6 on the side facing away from the flexible plate 2 toward the confluence plate 5; a drainage channel 44 is formed between the confluence plate 5 and the drainage plate 6;

[0062] In this embodiment, a first opening 51 is formed by penetrating the surface of the confluence plate 5 on the side facing the flexible plate 2 corresponding to the first region 41, and the drainage plate 6 covers the first opening 51 to form the recess 43;

[0063] At least one drainage hole 45 penetrating through the drainage plate 6 is provided in the region of the drainage plate 6 opposite to the second region 42, and at least one drainage groove 62 extending from the second region 42 to the first region 41 is provided on the surface of the drainage plate 6 close to the confluence plate 5. The confluence plate 5 covers one end of the drainage hole 45 close to the flexible plate 2 and covers the drainage groove 62 to form the drainage channel 44.

[0064] Correspondingly, the shapes of the flow guiding plate 6 and the current collecting plate 5 can be circular, square, rectangular or others, which are not limited herein. On the one hand, the flow guiding plate 6 is joined with the current collecting plate 5 to form the flow guiding plate 4. On the other hand, the flow guiding plate 6 also needs to provide support for the entire piezoelectric pump. Preferably, the material of the flow guiding plate 6 is a metallic material, such as brass, red copper, stainless steel, iron-nickel alloy, etc. The flow guiding groove 62 can be formed by semi-etching on one side of the metallic flow guiding plate 6, but it is not limited thereto. The material of the current collecting plate 5 can be determined and selected based on the principle that the linear expansion coefficients of the layers of the laminated structure match each other, so as to ensure the temperature stability of the micro piezoelectric pump, which will not be elaborated herein.

[0065] Preferably, the flow guiding holes 45 provided on the flow guiding plate 6 are arranged in one-to-one correspondence with the flow guiding channels 44, and the flow guiding holes 45 and the corresponding flow guiding channels 44 are communicated. That is, one flow guiding hole 45 is arranged corresponding to one flow guiding groove 62, but it is not limited thereto. Preferably, there are multiple flow guiding holes 45, for example, at least two, and the multiple flow guiding holes 45 are circumferentially and uniformly distributed in the second region 42 of the flow guiding plate 6 around the recessed portion 43.

[0066] It is not difficult to understand that the flow guiding groove 62 extends from the second region 42 of the flow guiding plate 6 to the first region 41. One end of the flow guiding groove 62 is communicated with the flow guiding hole 45 arranged in the second region 42 of the flow guiding plate 6, and the other end of the flow guiding groove 62 is communicated with the first opening 51, and then is communicated to the pump chamber 3 through the ventilation hole 211 on the flexible portion 21. The part between one end and the other end of the flow guiding groove 2 is sealed by the current collecting plate 5, thereby forming the flow guiding channel 44 for external gas to enter the pump chamber 3.

[0067] The regions where the fixing portion 22 is joined with the current collecting plate 5 are the outer joining region and the inner joining region. The outer joining region is arranged circumferentially around the inner joining region and is located outside the inner joining region. The inner joining region is arranged circumferentially around the flexible portion 21 and is located outside the flexible portion 21. A relief hole 52 is provided in the region of the current collecting plate 5 opposite to the elastic support portion 222 to avoid the elastic support portion 222, and prevent the elastic support portion 222 from forming a kinematic interference with the current collecting plate 5 when vibrating along with the piezoelectric actuator 1. The relief hole 52 is located between the outer joining region and the inner joining region, as Figures 4 - 6 shown;

[0068] Under the excitation of an electrical signal, the piezoelectric sheet 12 causes the piezoelectric actuator 1 to vibrate, so that the gas in the pump chamber 3 generates a pressure change, and then causes the flexible portion 21 to vibrate.

[0069] By arranging a drainage channel 44 inside the guide plate 4, or by forming the drainage channel 44 by the surface cooperation of the conduit plate 5 and the drainage plate 6 constituting the guide plate 4, so that the drainage channel 44 that will cause structural discontinuity is away from the surface of the side of the guide plate 4 or the conduit plate 5 facing the flexible plate 2, the distortion bulge toward the vibration plate 11 caused by the structural discontinuity at the connection point between the drainage channel 44 and the recessed portion 43 after gluing can be greatly reduced, thereby suppressing noise.

[0070] Example 2

[0071] The principles of this embodiment are basically the same as those of the first embodiment, except that: a first opening 51 is formed through the first area 41 corresponding to a side surface of the busbar 5 facing the flexible plate 2, and a side surface of the busbar 5 facing away from the flexible plate 2 is provided with at least one drainage groove 62 extending from the second area 42 to the first area 41, and the drainage plate 6 covers the first opening 51 to form a recessed portion 43, and covers the drainage groove 62 to form a drainage channel 44;

[0072] At least one drainage hole 45 penetrating the drainage plate 6 is provided in the area opposite to the second area 42. The drainage hole 45 is arranged opposite to the drainage groove 62 near one end of the flexible plate 2. One end of the drainage channel 44 is connected to the drainage hole 45, and the other end is connected to the recessed portion 43. Figure 7 shown.

[0073] Example 3

[0074] The principles of this embodiment are basically the same as those of the first embodiment, except that: a first opening 51 is formed through the first area 41 corresponding to the side surface of the busbar 5 facing the flexible plate 2, and at least one first drainage groove 54 extending from the second area 42 to the first area 41 is provided on the side surface of the busbar 5 facing away from the flexible plate 2;

[0075] The area of ​​the guide plate 6 opposite to the second area 42 is provided with at least one guide hole 45 penetrating the guide plate 6, and the surface of the guide plate 6 facing the collector plate 5 is provided with at least one second guide groove 61 extending from the second area 42 to the first area 41 and facing the first guide groove 54;

[0076] The drainage plate 6 covers the first opening 51 to form a recessed portion 43. The drainage hole 45 is disposed near one end of the flexible plate 2 and is opposite to the first drainage groove 54. The first drainage groove 54 cooperates with the second drainage groove 61 to form a drainage channel 44. One end of the drainage channel 44 is connected to the drainage hole 45, and the other end is connected to the recessed portion 43. Figure 8 shown.

[0077] Example 4

[0078] This embodiment is basically the same as Embodiments 1-3, except that: the vibrating plate 11 has a vibrating portion 11-1, an outer peripheral portion 11-2 and a connecting portion 11-3. The vibrating portion 11-1, the outer peripheral portion 11-2 and the connecting portion 11-3 can be integrally formed. The vibrating portion 11-1 is located at or near the center of the vibrating plate 11 and is disposed opposite to the flexible portion 21. The outer peripheral portion 11-2 surrounds the periphery of the vibrating portion 11-1 with a gap 11-4 in the plane direction perpendicular to the thickness direction. The connecting portion 11-3 is disposed in the gap 11-4 and connects the vibrating portion 11-1 to the outer peripheral portion 11-2. The connecting portion 11-3 elastically supports the vibrating portion 11-1 on the outer peripheral portion 11-2. The fixing portion 22 of the flexible plate 2 is joined to the outer peripheral portion 11-2 of the vibrating plate 11.

[0079] A first avoidance hole 223 is provided in the region of the fixing portion 22 opposite to the connecting portion 11-3 to avoid the connecting portion 11-3 and prevent the connecting portion 11-3 from forming a movement interference with the flexible plate 2 when vibrating along with the vibrating portion 11-1. The region where the fixing portion 22 is joined to the bus bar 5 is a second outer joining region and a second inner joining region. The second outer joining region is circumferentially disposed around the second inner joining region and is located outside the second inner joining region. The second inner joining region is circumferentially disposed around the flexible portion 21 and is located outside the flexible portion 21. A second avoidance hole 53 is provided in the region of the bus bar 5 opposite to the connecting portion 11-3 to avoid the connecting portion 11-3 and prevent the connecting portion 11-3 from forming a movement interference with the bus bar 5 when vibrating along with the vibrating portion 11-1. The first avoidance hole 223 and the second avoidance hole 53 are located in the region between the second outer joining region and the second inner joining region, as Figures 9 - 11 shown.

[0080] Based on the ideal embodiments of the present invention as inspiration, through the above description, relevant staff can completely make various changes and modifications without departing from the technical idea of this invention. The technical scope of this invention is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A piezoelectric pump, comprising a piezoelectric actuator (1), a flexible plate (2) and a guide plate (4), wherein the piezoelectric actuator (1) is provided with a flexible plate (2), wherein the flexible plate (2) has a flexible portion (21) located in the middle and a fixed portion (22) connected to the outer periphery of the flexible portion (21) and arranged around the flexible portion (21), and a gap is left between the flexible plate (2) and the piezoelectric actuator (1) to form a pump chamber (3) The flexible portion (21) is provided with a vent hole (211) opposite to the piezoelectric actuator (1); the flexible plate (2) is connected to the piezoelectric actuator (1) via a fixing portion (22); the guide plate (4) is arranged on a surface of the flexible plate (2) that is away from the piezoelectric actuator (1); when the piezoelectric actuator (1) vibrates, the gas in the pump chamber (3) produces a pressure change, thereby causing the flexible portion (21) to vibrate; Features: The guide plate (4) comprises a first region (41) located in the middle part and a second region (42) connected to the outer periphery of the first region (41) and arranged circumferentially around the first region (41); the first region (41) is arranged opposite to the flexible portion (21), and the first region (41) is recessed on one side of the surface facing the flexible plate (2) to form a recessed portion (43); the second region (42) is fixedly connected to the fixed portion (22); a drainage hole (45) which does not penetrate the guide plate (4) is provided on the side of the surface of the second region (42) facing away from the flexible plate (2); at least one drainage channel (44) is provided inside the guide plate (4); one end of at least one drainage channel (44) is connected to the drainage hole (45), and the other end is connected to the recessed portion (43).

2. The piezoelectric pump according to claim 1, characterized in that: The guide plate (4) comprises a guide plate (6) and a collector plate (5) which are stacked, and the collector plate (5) is arranged on a side close to the flexible plate (2); The recessed portion (43) extends from a side surface of the collector plate (5) close to the flexible plate (2) toward the guide plate (6); The drainage hole (45) extends from a side surface of the drainage plate (6) away from the flexible plate (2) toward the direction of the collecting plate (5); A drainage channel (44) is formed between the collecting plate (5) and the drainage plate (6).

3. The piezoelectric pump according to claim 2, characterized in that: A first opening (51) is formed by penetrating a first area (41) corresponding to a surface of one side of the collector plate (5) facing the flexible plate (2), and the guide plate (6) covers the first opening (51) to form the recessed portion (43); The area of ​​the guide plate (6) opposite to the second area (42) is provided with at least one guide hole (45) penetrating the guide plate (6); the surface of the guide plate (6) on one side close to the collector plate (5) is provided with at least one guide groove (62) extending from the second area (42) to the first area (41); the collector plate (5) covers the guide hole (45) at one end close to the flexible plate (2), and covers the guide groove (62) to form a guide channel (44).

4. The piezoelectric pump according to claim 2, characterized in that: The first area (41) corresponding to the side surface of the collector plate (5) facing the flexible plate (2) is penetrated to form a first opening (51); the side surface of the collector plate (5) facing away from the flexible plate (2) is provided with at least one drainage groove (62) extending from the second area (42) to the first area (41); the drainage plate (6) covers the first opening (51) to form the recessed portion (43), and covers the drainage groove (62) to form a drainage channel (44); The area of ​​the guide plate (6) opposite to the second area (42) is provided with at least one guide hole (45) penetrating the guide plate (6), and the guide hole (45) is arranged near one end of the flexible plate (2) and opposite to the guide groove (62).

5. The piezoelectric pump according to claim 2, characterized in that: A first opening (51) is formed through a first area (41) corresponding to a side surface of the busbar (5) facing the flexible plate (2), and a side surface of the busbar (5) facing away from the flexible plate (2) is provided with at least one first drainage groove (54) extending from the second area (42) to the first area (41); The area of ​​the guide plate (6) opposite to the second area (42) is provided with at least one guide hole (45) penetrating the guide plate (6); and the surface of the guide plate (6) on one side facing the collector plate (5) is provided with at least one second guide groove (61) extending from the second area (42) to the first area (41) and directly opposite to the first guide groove (54); The drainage plate (6) covers the first opening (51) to form the recessed portion (43), and the drainage hole (45) is arranged near one end of the flexible plate (2) and opposite to the first drainage groove (54), and the first drainage groove (54) cooperates with the second drainage groove (61) to form a drainage channel (44).

6. The piezoelectric pump according to any one of claims 1 to 5, characterized in that: The drainage holes (45) are arranged in one-to-one correspondence with the drainage channels (44), and the drainage holes (45) are communicated with the corresponding drainage channels (44).

7. The piezoelectric pump according to claim 6, characterized in that: There are a plurality of drainage holes (45), and the plurality of drainage holes (45) are evenly distributed in the second area (42) of the drainage plate (6) around the circumference of the recessed portion (43).

8. The piezoelectric pump according to claim 1, characterized in that: The piezoelectric actuator (1) comprises a vibration plate (11) and a piezoelectric sheet (12); at least one piezoelectric sheet (12) is bonded to one or both surfaces of the piezoelectric actuator (1) in a thickness direction; the piezoelectric sheet (12) is bonded to the vibration plate (11) to form the piezoelectric actuator (1); The piezoelectric actuator (1) has a first main surface and a second main surface arranged opposite to each other in the thickness direction, and the flexible plate (2) is provided on the first main surface or / and the second main surface of the piezoelectric actuator (1).

9. The piezoelectric pump according to claim 8, characterized in that: At least one connecting boss (111) protrudes from a surface of one side of the vibration plate (11) facing the flexible plate (2); a region of the fixing portion (22) opposite to the connecting boss (111) has a notch (221); an elastic supporting portion (222) is formed in the notch (221); and the connecting boss (111) and the elastic supporting portion (222) opposite thereto are fixedly connected.

10. The piezoelectric pump according to claim 8, characterized in that: The vibration plate (11) comprises a vibration part (11-1), a peripheral part (11-2) and a connecting part (11-3); the vibration part (11-1) and the flexible part (21) are arranged opposite to each other; the peripheral part (11-2) surrounds the vibration part (11-1) via a gap (11-4); the connecting part (11-3) is arranged in the gap (11-4) and connects the vibration part (11-1) and the peripheral part (11-2); the connecting part (11-3) elastically supports the vibration part (11-1) on the peripheral part (11-2); and the fixing part (22) is joined to the peripheral part (11-2) of the vibration plate (11).

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