Piezoelectric micro pump

Abstract

The utility model provides a piezoelectric micro pump which comprises a pump body. The pump body is provided with a square cavity. The vibration isolation piece is horizontally arranged in the middle of the square cavity, the square cavity is divided into an upper cavity body and a lower cavity body which are independent, two holes are formed in the end walls of the upper cavity body and the lower cavity body in a penetrating mode respectively, and one hole is formed in the middle of the end wall of each cavity body; the one-way valve is arranged on one hole of the cavity; the actuator is attached to one face of the vibration isolation piece, and electric connection is formed on the attached face; and the deformation sheet is arranged on the other surface of the vibration isolation sheet. Compared with the prior art, the square cavity can provide a larger braking area for the actuator, so that the vibration amplitude is increased, the formed gas pressure is increased, and larger fluid pressure and flow are brought.

Description

Technical Field

[0001] The utility model relates to the technical field of micro pumps, in particular to a piezoelectric micro pump. Background Art

[0002] Piezoelectric micropumps are generally used in some portable electronic devices, such as some portable blood pressure monitors, head-mounted massagers, etc. They are relatively small pumps used to deliver positive pressure or provide vacuum. In order to achieve the desired goals of small size, high efficiency and silent operation, such pumps must operate at very high frequencies, usually around 20kHz or higher. In order to operate at high frequencies, the valves equipped with the pump must respond to high-frequency oscillating pressure, which can be rectified to produce a net fluid flow through the pump.

[0003] The piezoelectric micropump in the prior art has the problem of limited vibration cavity area and small braking area of ​​the actuator, which leads to insufficient vibration amplitude and small gas pressure, which in turn affects the fluid pressure and flow. Therefore, a new piezoelectric micropump is urgently needed to solve some problems existing in the prior art. Utility Model Content

[0004] The utility model aims to provide a piezoelectric micro pump to solve some problems existing in the prior art.

[0005] To achieve the above purpose, the utility model adopts the following technical solution: a piezoelectric micro pump, comprising:

[0006] A pump body, wherein the pump body has a square cavity;

[0007] A vibration isolation plate, the vibration isolation plate is horizontally arranged in the middle of the square cavity, and the square cavity is divided into two independent cavities, the end walls of the upper and lower cavities are respectively penetrated with two holes, and one of the holes is opened in the middle of the end wall of the cavity;

[0008] a one-way valve, the one-way valve being disposed on one of the holes in the cavity;

[0009] An actuator, the actuator is bonded to one of the surfaces of the vibration isolation plate and forms an electrical connection on the bonded surface;

[0010] The deformation plate is arranged on the other surface of the vibration isolation plate.

[0011] Furthermore, the vibration isolation plate is made of elastic material.

[0012] Furthermore, the vibration isolation plate is a polyurethane film or a PET film, or the vibration isolation plate is made of a composite material of a polyurethane film and a metal sheet, or the vibration isolation plate is made of a composite material of a PET film and a metal sheet.

[0013] Furthermore, there is a pressure node on the plane area where the vibration isolation plate and the actuator are attached. The pressure node is in an irregular ring shape, and the pressure at the pressure node tends to zero, and the pressures on both sides of the pressure node are in opposite directions.

[0014] Furthermore, the one-way valve is a membrane valve with a pressure relief function.

[0015] Furthermore, the one-way valve comprises:

[0016] A spacer, wherein the spacer has a valve area and a gas leakage area penetrating the upper and lower ends thereof, wherein the gas leakage area is arranged beside the valve area, and the gas leakage area is connected with the valve area through the communication area;

[0017] Plates, wherein two plates are provided, and the two plates are respectively provided on the upper and lower sides of the spacer, and the two plates are located in the valve area and vertically penetrate the corresponding first holes, and one of the plates is located in the air release area and vertically penetrates the third hole;

[0018] The valve is arranged between the spacer and the plate with the third hole. The valve and the plate with the third hole are located in the valve area and vertically penetrate through corresponding second holes respectively. The second hole is arranged away from the first hole.

[0019] Furthermore, the actuator is made of piezoelectric material.

[0020] Furthermore, the actuator is any one of a square actuator, a polygonal actuator or a circular actuator.

[0021] Further, the upper and lower surfaces of the actuator are respectively provided with electrodes, and a plurality of electrodes are provided on the bonding surface of the actuator and the vibration isolation plate, forming an electrical connection with the plurality of electrodes of the vibration isolation plate;

[0022] Wherein, an annular electrode is arranged on the outer side of the bonding surface between the actuator and the vibration isolation plate, and the annular electrode is connected with the electrode on the other side of the actuator through the side electrical connection.

[0023] Compared with the existing technology, the above technical solution has the following beneficial effects: the square cavity can provide a larger braking area for the actuator, thereby increasing the vibration amplitude, increasing the gas pressure formed, and bringing greater fluid pressure and flow. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0025] Figure 1 It is a simplified structural diagram of the utility model;

[0026] Figure 2 It is a schematic diagram of the explosion structure of the utility model;

[0027] Figure 3 It is a partial structural schematic diagram of the utility model;

[0028] Figure 4 It is a partial structural schematic diagram of the vibration isolation plate 2 in the utility model;

[0029] Figure 5 It is a pressure diagram of the utility model;

[0030] Figure 6 It is a partial structural schematic diagram of the actuator 4 of the utility model when it is square;

[0031] Figure 7 It is a partial structural schematic diagram of the actuator 4 of the utility model when it is a polygon;

[0032] Figure 8 It is a partial structural schematic diagram of the actuator 4 of the utility model when it is circular;

[0033] Fig. 9 It is a structural schematic diagram of one type of the monolithic valve 3 in the utility model;

[0034] Fig.10 It is a schematic diagram of the local structure of the valve 34 of the utility model when it is attached to the second plate 33;

[0035] Fig.11 It is a schematic diagram of the local structure of the valve 34 of the utility model when it is attached to the first plate 32;

[0036] Fig.12 It is another structural schematic diagram of the single-piece valve 3 in the utility model.

[0037] Explanation of the accompanying drawings: 1. Pump body; 11. Upper pump shell; 12. Lower pump shell; 13. Upper cavity; 14. Lower cavity; 141. Fourth hole; 142. Fifth hole; 15. Air outlet; 16. Leakage hole; 2. Vibration isolation plate; 21. Electrical connection input terminal; 22. Pressure node; 3. One-way valve; 31. Spacer; 311. Baffle; 312. Valve area; 313. Leakage area; 314. Connecting area; 32. First plate; 33. Second plate; 34. Valve; 35. First hole; 36. Second hole; 37. Third hole; 4. Actuator; 41. Ring electrode; 411. Side electrical connection; 42. Circular electrode; 5. Deformation plate. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail in combination with the embodiments below. It should be understood that the specific embodiments described here are only used to explain the utility model, and are not used to limit the utility model.

[0039] In view of the problems existing in the prior art, the utility model provides a piezoelectric micro pump, which is described in detail below in conjunction with the accompanying drawings.

[0040] See also Figure 1-Figure 11 As shown, the technical solution adopted in this specific embodiment is: a piezoelectric micro pump, including a pump body 1, a vibration isolation plate 2, a one-way valve 3, an actuator 4, and a deformation plate 5, the pump body 1 includes an upper pump shell 11 and a lower pump shell 12, the upper pump shell 11 and the lower pump shell 12 are connected to form a square cavity or an approximately square cavity for accommodating fluid, and the ratio between the side length and the height of the cavity is greater than 2.5.

[0041] A vibration isolation plate 2 is provided in the middle of the cavity, and the vibration isolation plate 2 separates the square cavity or the approximately square cavity into an upper cavity 13 and a lower cavity 14, and the two cavities are independent. Specifically, the vibration isolation plate 2 generally presents a square structure, and its edge is pressed with the shell ends of the upper pump shell 11 and the lower pump shell 12 to divide the cavity into two independent parts, upper and lower. One side of the vibration isolation plate 2 extends to the outside of the pump body 1 to form a thin strip, and the tail end of the thin strip is the electrical connection input terminal 21.

[0042] It should be specifically explained that a fourth hole 141 is respectively provided through the center of the end wall of the upper cavity 13 and the lower cavity 14, and a fifth hole 142 is also provided through the end wall of the upper cavity 13 and the lower cavity 14, and the fifth hole 142 is arranged at any position of the end wall except the position of the fourth hole 141. A one-way valve 3 is installed at one of the fourth hole 141 or the fifth hole 142 to allow the fluid to flow through the cavity when in use.

[0043] The vibration isolation plate 2 is arranged between the actuator 4 and the deformable plate 5, and the actuator 4 is electrically connected to the bonding surface of the vibration isolation plate 2. Specifically, the upper and lower surfaces of the actuator 4 are respectively provided with electrodes, wherein at least two electrodes are arranged on the bonding surface of the actuator 4 and the vibration isolation plate 2, and the two electrodes or multiple electrodes of the actuator 4 and the vibration isolation plate 2 are electrically connected on the bonding surface.

[0044] Among them, an annular electrode 41 is arranged outside the bonding surface of the actuator 4 and the vibration isolation plate 2, and the annular electrode 41 is connected to the electrode on the other side of the actuator 4 through the side electrical connection 411, and the annular electrode 41 forms an electrical contact with at least one of the multiple conductive tracks of the vibration isolation plate 2. At this time, a circular electrode 42 is arranged inside the annular electrode 41 of the actuator 4.

[0045] Preferably, the actuator 4 is made of piezoelectric material and can be a square actuator, a nearly square actuator, a polygonal actuator or a circular actuator. After voltage is applied to the electrodes of the actuator 4, the actuator 4 will expand or shrink due to the piezoelectric effect. Since the actuator 4 is bonded to the vibration isolation plate 2 and the deformation plate 5 as a whole, the deformation plate 5 will deform when the actuator 4 expands or shrinks. By inputting an alternating voltage to the actuator 4, the deformation plate 5 will drive the vibration isolation plate 2 to vibrate.

[0046] Preferably, the vibration isolation plate 2 is made of a material with elastic characteristics, which may be a polyurethane film, or a PET film, or may be made of a composite material of a polyurethane film or a PET film and a metal sheet.

[0047] like Figure 5 As shown, the actuator 4 and the deformable plate 5 generate waveform vibration under the action of the alternating electric field. There is a pressure node 22 in the plane area where the vibration isolation plate 2 and the actuator 4 are in contact. The pressure node 22 is irregularly annular, and the pressure there tends to be zero. The pressures on both sides of the pressure node 22 are in opposite directions, thereby forming two peak areas, one on the inner side of the pressure node 22 and the other on the outer side of the pressure node 22. Under the action of pressure, the fluid is driven to flow in one direction.

[0048] The driving frequency of the actuator 4 shown is over 20 KHz, which is beyond the range that can be perceived by human ears, and the effect of the vibration is close to silence.

[0049] Preferably, the one-way valve 3 is a one-way valve with a pressure relief function, which has both air outlet and pressure relief functions. It can solve the problem that the existing piezoelectric micropump does not have a pressure relief function, resulting in the application equipment needing to be separately configured with a pressure relief valve. It can well save the internal space of the application equipment, reduce the size of the equipment and reduce costs, and is more convenient to use.

[0050] It should be specifically explained that the one-way valve 3 includes a spacer 31, a first plate 32, a second plate 33, and a valve 34. The spacer 31 has a hollow area that runs through the upper and lower ends thereof in the longitudinal direction. A baffle 311 extends horizontally in the hollow area to separate the hollow area into a valve area 312 and a gas release area 313. The valve area 312 and the gas release area 313 are connected through a connecting area 314. The first plate 32 and the second plate 33 are respectively arranged on the upper and lower sides of the spacer 31. The first plate 32 and the second plate 33 are respectively vertically penetrated at the position of the valve area 312 to form a first hole 35. The first hole 35 on the first plate 32 and the first hole 35 on the second plate 33 are arranged correspondingly.

[0051] The valve 34 is arranged between the second plate 33 and the spacer 31, and the second plate 33 and the valve 34 are respectively vertically penetrated by a second hole 36 at the position of the valve area 312. The second hole 36 on the second plate 33 corresponds to the second hole 36 on the valve 34, and the second hole 36 is arranged offset from the first hole 35.

[0052] It should be specifically explained that a third hole 37 is vertically penetrated through the second plate 33 at the position of the air leakage area 313. When working, the air outlet hole 15 of the pump body 1, the second hole 36 on the second plate 33, the third hole 37, and the air leakage hole 16 of the pump body are connected in sequence to form an air leakage channel.

[0053] Specifically, the communication area 314 is arranged at the extension port of the baffle 311, and the area of ​​the baffle 311 is larger than the area of ​​the communication area 314. Preferably, two baffles 311 are arranged between the valve area 312 and the air release area 313, and the two baffles 311 are relatively symmetrically arranged, and the communication area 314 is arranged between the relatively extended ports of the two baffles 311.

[0054] Preferably, the valve region 312 is disposed at the center of the spacer 31 , and its area is larger than that of the air leakage region 313 . The area of ​​the air leakage region 313 is approximately one fifth of that of the valve region 312 .

[0055] In addition, the valve area 312 may be a one-piece area or may be composed of multiple interconnected areas.

[0056] It should be specifically noted that two air leakage areas 313 can be provided, and the two air leakage areas 313 are symmetrically arranged at opposite sides of the valve area 312. In fact, the specific number of the air leakage areas 313 is not limited to one or two, and can be adjusted according to actual design requirements.

[0057] The one-way valve 3 is installed inside the pump body 1. When the actuator 4 is working, the vibration of the actuator 4 can bring about changes in the airflow pressure in the cavity area. Synchronously with the input frequency, the one-way valve 3 vibrates up and down at the same frequency under the changes in the air pressure on both sides. When the valve 34 is close to the second plate 33, the first hole 35 of the first plate 32 is connected to the second hole 36 of the second plate 33. At this time, the gas pressure in the pump cavity is greater than that in the airway, and the air pump is in an exhaust state; when the valve 34 is close to the first plate 32, the pressure in the airway is greater than that in the pump cavity, the valve is in a closed state, and the air pump is in a stopped pumping state at this time; at this time, since the up and down vibration of the valve 34 is the same frequency and high frequency action as the actuator, the action time is very short. At this time, the action area of ​​the valve 34 only moves up and down in the middle area of ​​the spacer 31, and the third hole 37 is closed by the valve 34 and is always in a closed state;

[0058] When the actuator 4 stops working, the pressure in the pump chamber is connected to the outside, and the pressure in the air outlet pipe is greater than that in the pump chamber for a long time. The valve 34 not only clings to the first plate 32 in the central area, but also in the peripheral air leakage hole 16 area, since the pressure in the air outlet pipe cannot be relieved, the gas will overflow to the outside area through the air outlet hole 15, making the valve 34 cling to the first plate 32, thereby opening the third hole 37, and then realizing the opening of the air leakage hole 16, and the air pressure in the air outlet pipe is discharged through the air leakage hole 16;

[0059] When the actuator 4 works again, the pressure in the pump chamber is greater than that in the air outlet pipe, and the valve 34 will resume closing the third hole 37 under the action of pressure and resume the high-frequency action air outlet state.

[0060] See also Fig.12 As shown, the valve 34 of the monolithic valve 3 can also be arranged between the first plate 32 and the spacer 31. In this case, the first plate 32 is located at the pressure relief area 313 and vertically penetrates through a third hole 37. When there is pressure on the end surface of the first plate 32, the valve 34 closes the third hole 37 on the first plate 32. The purpose of providing the third hole 37 on the first plate 37 is to use air pressure to push the valve 34 onto the second plate 33.

[0061] The square or nearly square cavity can provide a larger braking area for the actuator 4, thereby increasing the vibration amplitude, increasing the gas pressure formed, and bringing about a greater fluid pressure and flow rate. At the same time, it has both the air outlet and pressure relief functions. The application equipment does not need to install a separate pressure relief valve, which can save the internal space of the application equipment, reduce the size of the equipment and reduce costs. It is easy to use and has great value for promotion and application.

[0062] In the description of the present invention, unless otherwise specified, "multiple" means two or more; the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third" and the like are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0063] The above description is only used to illustrate the technical solution of the utility model rather than to limit it. Other modifications or equivalent substitutions made to the technical solution of the utility model by ordinary technicians in this field should be included in the scope of the claims of the utility model as long as they do not depart from the spirit and scope of the technical solution of the utility model.

Claims

1. A piezoelectric micro pump, characterized in that: include: A pump body, wherein the pump body has a square cavity; A vibration isolation plate, the vibration isolation plate is horizontally arranged in the middle of the square cavity, and the square cavity is divided into two independent cavities, the end walls of the upper and lower cavities are respectively penetrated with two holes, and one of the holes is opened in the middle of the end wall of the cavity; a one-way valve, the one-way valve being disposed on one of the holes in the cavity; An actuator, the actuator is bonded to one of the surfaces of the vibration isolation plate and forms an electrical connection on the bonded surface; The deformation plate is arranged on the other surface of the vibration isolation plate.

2. The piezoelectric micro pump according to claim 1, characterized in that: The vibration isolation plate is made of elastic material.

3. The piezoelectric micro pump according to claim 1, characterized in that: The vibration isolation plate is a polyurethane film or a PET film, or the vibration isolation plate is made of a composite material of a polyurethane film and a metal sheet, or the vibration isolation plate is made of a composite material of a PET film and a metal sheet.

4. The piezoelectric micro pump according to claim 1, characterized in that: There is a pressure node on the plane area where the vibration isolation plate and the actuator are attached. The pressure node is in an irregular ring shape, and the pressure at the pressure node tends to zero. The pressures on both sides of the pressure node are in opposite directions.

5. The piezoelectric micro pump according to claim 1, characterized in that: The one-way valve is a membrane valve with a pressure relief function.

6. The piezoelectric micro pump according to any one of claims 1 or 5, characterized in that: The one-way valve comprises: A spacer, wherein the spacer has a valve area and a gas leakage area penetrating the upper and lower ends thereof, wherein the gas leakage area is arranged beside the valve area, and the gas leakage area is connected with the valve area through the communication area; Plates, two plates are provided, the two plates are respectively provided on the upper and lower sides of the spacer, the two plates are located in the valve area and vertically penetrate the corresponding first holes, and the plates are located in the air release area and vertically penetrate the third holes; The valve is arranged between the spacer and any one of the plates, and the valve and one of the plates are respectively vertically penetrated at the position of the valve area to open a corresponding second hole, and the second hole is arranged away from the first hole.

7. The piezoelectric micro pump according to claim 1, characterized in that: The actuator is made of piezoelectric material.

8. The piezoelectric micropump according to any one of claims 1 or 7, characterized in that: The actuator is any one of a square actuator, a polygonal actuator or a circular actuator.

9. The piezoelectric micro pump according to claim 8, characterized in that: The upper and lower surfaces of the actuator are respectively provided with electrodes, and a plurality of electrodes are provided on the contact surface between the actuator and the vibration isolation plate, and are electrically connected with the plurality of electrodes of the vibration isolation plate; Wherein, an annular electrode is arranged on the outer side of the bonding surface between the actuator and the vibration isolation plate, and the annular electrode is connected with the electrode on the other side of the actuator through the side electrical connection.

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