Piezoelectric micropump

Abstract

The present invention provides a piezoelectric micropump comprising: a pump body having a rectangular cavity; a vibration spacer horizontally installed at the center of the rectangular cavity, dividing the rectangular cavity into two independent upper and lower chambers, with two holes drilled through each of the end walls of the upper and lower chambers, one of which is located at the center of the end wall of the chamber; a check valve provided in one of the holes of the chamber; an actuator in close contact with one surface of the vibration spacer and forming an electrical connection on the contact surface; and a deformation piece provided on the other surface of the vibration spacer. In the present invention, the rectangular cavity has a larger operating area due to the actuator, thereby increasing the vibration amplitude, increasing the formed gas pressure, and thus increasing the fluid pressure and flow rate.

Description

Technical Field

[0001] The present invention relates to the technical field of micropumps, and more specifically, to piezoelectric micropumps.

Background Art

[0002] Piezoelectric micropumps are generally used in portable electronic devices such as portable blood pressure monitors and head-mounted massagers, and are relatively small pumps used to send positive pressure or provide a vacuum. To achieve the desirable goals of small size, high efficiency, and quiet operation, such pumps need to operate at a very high frequency, usually about 20 kHz or more. To operate at a high frequency, the valves equipped in the pump need to respond to the high-frequency vibration pressure. This vibration pressure can be rectified to generate a net fluid flow rate through the pump.

[0003] Conventional piezoelectric micropumps have a limited vibration cavity area and a small actuator operating area, resulting in insufficient vibration amplitude, relatively low gas pressure formed, and affecting the fluid pressure and flow rate. Therefore, in order to solve some problems existing in the prior art, the development of a new piezoelectric micropump is urgently required.

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to provide a piezoelectric micropump in order to solve some problems existing in the prior art.

Means for Solving the Problems

[0005] To achieve the above object, the present invention adopts the following technical solutions. A piezoelectric micropump, a pump body having a rectangular cavity, A vibration spacer is horizontally installed at the center of a rectangular cavity, dividing the rectangular cavity into two independent upper and lower chambers, with two holes drilled through each of the end walls of the upper and lower chambers, one of which is located at the center of the end wall of the chamber. A check valve is provided in one of the holes in the chamber, An actuator that is in close contact with one surface of a vibration spacer and forms an electrical connection on the surface in which it is in contact, The vibration spacer includes a deformable piece provided on the other side of the spacer.

[0006] Furthermore, the vibration spacer is manufactured from an elastic material.

[0007] Furthermore, the vibration spacer may be a polyurethane thin film or a PET thin film, or it may be made from a composite material of a polyurethane thin film and a metal sheet, or it may be made from a composite material of a PET thin film and a metal sheet.

[0008] Furthermore, the vibration spacer has a pressure node portion in a planar region that is in close contact with the actuator, and the pressure node portion exhibits an irregular annular shape, and the pressure at the pressure node portion approaches zero, while the pressure on both sides of the pressure node portion is directed in opposite directions.

[0009] Furthermore, the check valve is a thin-film valve equipped with a pressure release function.

[0010] Furthermore, the check valve is A separator, wherein the separator has a valve region and an exhaust region that penetrate both its upper and lower ends, the exhaust region is provided next to the valve region, and the exhaust region communicates with the valve region via a communication region, A plate, comprising two plates, the two plates being positioned above and below the separator, with corresponding first holes vertically penetrating each plate at positions in the valve region, and a third hole vertically penetrating each plate at a position in the exhaust region, A membrane, wherein the membrane is placed between a separator and a plate having a third hole, and a corresponding second hole is formed vertically through the membrane and the plate having the third hole at a position located in the valve region, with the second hole offset from the first hole.

[0011] Furthermore, the actuator is manufactured from a piezoelectric material.

[0012] Furthermore, the actuator is one of a rectangular actuator, a polygonal actuator, or a circular actuator.

[0013] Furthermore, electrodes are arranged on each of the two upper and lower surfaces of the actuator, and multiple electrodes are installed on the surface of the actuator that is in close contact with the vibration spacer, forming an electrical connection with the multiple electrodes of the vibration spacer. An annular electrode is installed on the outer surface of the actuator that is in contact with the vibration spacer, and the annular electrode communicates with an electrode on the other side of the actuator via an electrical connection on its side. [Effects of the Invention]

[0014] Adopting the above technical solution provides the following beneficial effects compared to conventional technology: The rectangular cavity increases the vibration amplitude by providing a larger working area for the actuator, thereby increasing the formed gas pressure and resulting in greater fluid pressure and flow rate. [Brief explanation of the drawing]

[0015] To more clearly describe embodiments of the present invention or technical solutions in the prior art, the drawings necessary for describing embodiments or the prior art will be briefly described below. However, the drawings in the following description represent only a few embodiments of the present invention, and it will be obvious to those skilled in the art that other drawings can be obtained based on these drawings without any creative effort. [Figure 1] This is a schematic diagram of the structure of the present invention. [Figure 2] It is a schematic diagram of the decomposition structure of the present invention. [Figure 3] It is a schematic diagram of the partial structure of the present invention. [Figure 4] It is a schematic diagram of the partial structure of the vibration spacer 2 in the present invention. [Figure 5] It is a pressure diagram of the present invention. [Figure 6] It is a schematic diagram of the partial structure when the actuator 4 of the present invention is square. [Figure 7] It is a schematic diagram of the partial structure when the actuator 4 of the present invention is polygonal. [Figure 8] It is a schematic diagram of the partial structure when the actuator 4 of the present invention is circular. [Figure 9] It is a schematic diagram of the structure of an example of the check valve 3 in the present invention. [Figure 10] It is a schematic diagram of the partial structure when the membrane 34 is in close contact with the second plate 33 in the present invention. [Figure 11] It is a schematic diagram of the partial structure when the membrane 34 is in close contact with the first plate 32 in the present invention. [Figure 12] It is another schematic diagram of the structure of the check valve 3 in the present invention.

Embodiments for Carrying Out the Invention

[0016] To more clearly illustrate the object, technical solution, and advantages of the present invention, the present invention will be described in more detail below with reference to embodiments. It should be understood that the specific embodiments described herein are for the purpose of explaining the present invention and are not intended to limit the present invention.

[0017] The present invention provides a piezoelectric micropump for the problems existing in the prior art, and the present invention will be described in detail below with reference to the drawings.

[0018] As shown in Figures 1 to 11, the technical solution employed in this specific embodiment is as follows: The piezoelectric micropump includes a pump body 1, a vibration spacer 2, a check valve 3, an actuator 4, and a deformation piece 5. The pump body 1 includes an upper pump casing 11 and a lower pump casing 12. The upper pump casing 11 and the lower pump casing 12 are connected to form a rectangular or substantially rectangular cavity used to contain fluid, and the ratio of the side length to the height of the cavity is greater than 2.5.

[0019] A vibration spacer 2 is installed in the center of the cavity, and the vibration spacer 2 divides the rectangular or approximately rectangular cavity into an upper chamber 13 and a lower chamber 14, with the two chambers being independent of each other. Specifically, the vibration spacer 2 has a roughly rectangular structure, and its edges are pressed against the casing ends of the upper pump casing 11 and the lower pump casing 12, dividing the cavity into two independent upper and lower parts. One side of the vibration spacer 2 extends to the outside of the pump body 1, forming a thin strip, and the end of this thin strip becomes an electrical connection input terminal 21.

[0020] Furthermore, a fourth hole 141 is provided through the center of the end walls of the upper chamber 13 and the lower chamber 14, and a fifth hole 142 is provided through the end walls of the upper chamber 13 and the lower chamber 14, respectively. The fifth hole 142 is installed at any position on the end wall other than the position of the fourth hole 141. A check valve 3 is installed at either the fourth hole 141 or the fifth hole 142 to allow fluid to flow through the chamber during use.

[0021] The vibration spacer 2 is installed between the actuator 4 and the deformation piece 5, and forms an electrical connection on the surface of the actuator 4 that is in close contact with the vibration spacer 2. Specifically, electrodes are installed on the upper and lower surfaces of the actuator 4, and at least two electrodes are installed on the surface of the actuator 4 that is in close contact with the vibration spacer 2. The two or more electrodes of the actuator 4 and the vibration spacer 2 form an electrical connection on the surfaces that are in close contact.

[0022] Here, an annular electrode 41 is installed on the outside of the surface of the actuator 4 that is in contact with the vibration spacer 2, and the annular electrode 41 communicates with an electrode on the other side of the actuator 4 via an electrical connection part 411 on the side. The annular electrode 41 forms electrical contact with at least one of the multiple conductive rails of the vibration spacer 2. In this case, a circular electrode 42 is installed inside the annular electrode 41 in the actuator 4.

[0023] Preferably, the actuator 4 is made of a piezoelectric material and may be a rectangular actuator, a substantially rectangular actuator, a polygonal actuator, or a circular actuator. When a voltage is applied to the electrodes of the actuator 4, the actuator 4 expands or contracts due to the piezoelectric effect, and the actuator 4, the vibration spacer 2, and the deformation piece 5 become tightly packed and integrated. As a result, the deformation piece 5 deforms due to the expansion or contraction of the actuator 4, and when an alternating voltage is input to the actuator 4, the deformation piece 5 vibrates the vibration spacer 2.

[0024] Preferably, the vibration spacer 2 is made of a material having elastic properties, and may be a polyurethane thin film, a PET thin film, or a composite material of a polyurethane thin film or a PET thin film and a metal sheet.

[0025] As shown in Figure 5, the actuator 4 and deformation piece 5 undergo waveform vibration due to the action of an alternating electric field. The vibration spacer 2 has a pressure node portion 22 in a planar region in close contact with the actuator 4. This pressure node portion 22 exhibits an irregular annular shape, and the pressure there approaches zero, while the pressure on both sides of the pressure node portion 22 is directed in opposite directions. As a result, two peak regions are formed, one inside the pressure node portion 22 and the other outside the pressure node portion 22, and the fluid flows in one direction due to the pressure action.

[0026] The driving frequency of the actuator 4 shown in the diagram is 20 kHz or higher, which is beyond the range that can be perceived by the human ear, and the vibration effect is almost silent.

[0027] Preferably, the check valve 3 is a check valve equipped with a pressure release function, combining gas venting and pressure release functions, solving the problem of conventional piezoelectric micropumps which lack a pressure release function and therefore require a pressure release valve to be installed in the applicable equipment, effectively saving internal space in the applicable equipment, reducing the volume of the equipment, lowering costs, and making it easier to use.

[0028] The check valve 3 includes a separator 31, a first plate 32, a second plate 33, and a membrane 34. The separator 31 has hollow regions that penetrate vertically through both its upper and lower ends. A stopper 311 extends horizontally within these hollow regions, dividing them into a valve region 312 and an exhaust region 313. The valve region 312 and the exhaust region 313 communicate with each other via a communication region 314. The first plate 32 and the second plate 33 are installed on the upper and lower sides of the separator 31, respectively. A first hole 35 is vertically opened in the valve region 312 of the first plate 32 and the second plate 33, and the first hole 35 of the first plate 32 and the first hole 35 of the second plate 33 are installed correspondingly.

[0029] The membrane 34 is installed between the second plate 33 and the separator 31. Second holes 36 are vertically penetrated through the second plate 33 and the membrane 34 at positions located in the valve region 312. The second holes 36 of the second plate 33 and the second holes 36 of the membrane 34 correspond to each other, and the second holes 36 are offset from the first holes 35.

[0030] Furthermore, a third hole 37 is provided vertically through the second plate 33 at a position located in the exhaust region 313. During operation, the gas vent hole 15 of the pump body 1, the second hole 36 of the second plate 33, the third hole 37, and the exhaust hole 16 of the pump body are connected in sequence to form an exhaust channel.

[0031] Specifically, the communication region 314 is installed in the extended port of the stopper 311, and the area of ​​the stopper 311 is larger than the area of ​​the communication region 314. Preferably, two stoppers 311 are installed between the valve region 312 and the exhaust region 313, and the two stoppers 311 are installed symmetrically opposite each other, and the communication region 314 is installed between the opposite extended ports of the two stoppers 311.

[0032] Preferably, the valve region 312 is located at the center of the separator 31, and its area is larger than the area of ​​the exhaust region 313. The area of ​​the exhaust region 313 is approximately one-fifth of the area of ​​the valve region 312.

[0033] Furthermore, the valve region 312 consists of an entire region or a region formed by interconnecting multiple parts.

[0034] Furthermore, two exhaust regions 313 may be installed, and the two exhaust regions 313 are installed symmetrically on opposite sides of the valve region 312. In practice, the specific number of exhaust regions 313 is not limited to one or two, but can be adjusted according to the actual design needs.

[0035] The check valve 3 is installed inside the pump body 1. When the actuator 4 operates, the vibration of the actuator 4 synchronizes the pressure change of the airflow in the chamber with the input frequency, and the check valve 3 vibrates up and down at the same frequency due to the change in air pressure on both sides. When the membrane 34 approaches the second plate 33, the first hole 35 of the first plate 32 and the second hole 36 of the second plate 33 communicate. At this time, the gas pressure in the pump chamber is higher than the gas pressure in the air passage, the air pump is in an exhaust state, and the membrane 34 is in close contact with the first plate 32. In this case, the pressure in the air passage is higher than the pressure in the pump chamber, the valve closes, and the air pump is in a pumping stop state. At this time, the up and down vibration of the membrane 34 is at the same high frequency as the actuator, so the operating time is very short. At this time, the region of up and down movement of the membrane 34 is only the central region of the separator 31, and the third hole 37 is sealed by the membrane 34 and is always in a closed state.

[0036] When actuator 4 stops operating, the pressure inside the pump chamber is connected to the outside, and the pressure in the exhaust pipe remains higher than the pressure inside the pump chamber for a long time. As a result, the membrane 34 is not only in close contact with the first plate 32 in its central region, but also unable to release the pressure in the exhaust pipe in the region of the exhaust port 16 on its outer circumference. Consequently, gas overflows to the outside through the vent hole 15, causing the membrane 34 to adhere tightly to the first plate 32, which in turn opens the third hole 37 and further opens the exhaust port 16, releasing the air pressure inside the exhaust pipe through the exhaust port 16.

[0037] When actuator 4 is activated again, the pressure inside the pump chamber becomes higher than the pressure inside the exhaust pipe, and the membrane 34, due to the action of the pressure, seals the third hole 37 again and resumes operating at a high frequency to exhaust.

[0038] As shown in Figure 12, the membrane 34 of the check valve 3 can also be installed between the first plate 32 and the separator 31. In this case, a third hole 37 is opened vertically through the first plate 32 at a position located in the pressure release region 313. When pressure is present on the end face of the first plate 32, the membrane 34 seals the third hole 37 of the first plate 32. The presence of the third hole 37 in the first plate 37 serves to press the membrane 34 against the second plate 33 using air pressure.

[0039] The rectangular or semi-rectangular cavity provides a larger working area for the actuator 4, increasing the vibration amplitude, the resulting gas pressure, and thus the fluid pressure and flow rate. Furthermore, it combines gas venting and pressure release functions, eliminating the need for separate pressure release valves in applicable equipment. This effectively saves internal space in the equipment, reduces its volume, lowers costs, and simplifies its use, making it highly valuable for widespread adoption and application.

[0040] In this description of the present invention, unless otherwise specified, "multiple" means two or more. The directions or positional relationships indicated by terms such as "up," "down," "left," "right," "inside," "outside," "tip," "rear end," "head," and "tail" are based on the directions or positional relationships shown in the drawings and are intended solely to facilitate and simplify the description of the present invention. They do not indicate or imply that the shown devices or elements have a specific direction or must be configured and operate in a specific direction, and should not be understood as limiting the present invention. Furthermore, terms such as "first," "second," and "third" are for illustrative purposes only and should not be understood as indicating or implying relative importance.

[0041] The foregoing is used solely to illustrate, and not to limit, the technical solutions of the present invention, and any other modifications or equivalent substitutions made by those skilled in the art to the technical solutions of the present invention should all be included in the claims of the present invention, as long as they do not depart from the spirit and scope of the technical solutions of the present invention. [Explanation of Symbols]

[0042] 1. Pump body 11. Upper pump casing 12 Lower pump casing 13 Upper Room 14 Lower chamber 141 Hole 4 142 Hole 5 15. Vent holes 16 exhaust holes 2. Vibration Spacer 21 Electrical connection input terminals 22 Pressure node section 3. Check valve 31 Separator 311 Stopper 312 Valve area 313 Exhaust Region 314 Communication area 32 First Plate 33 Second Plate 34 Membrane 35 Hole 1 36 2nd hole 37 Hole 3 4 Actuators 41 Annular electrode 411 Side electrical connection 42 circular electrodes 5 Deformed pieces

Claims

1. It is a piezoelectric micropump, A pump body having a rectangular cavity, A vibration spacer is horizontally installed at the center of a rectangular cavity, dividing the rectangular cavity into two independent upper and lower chambers, with two holes drilled through each of the end walls of the upper and lower chambers, one of which is located at the center of the end wall of the chamber. A check valve is provided in one of the holes in the chamber, An actuator that is in close contact with one surface of a vibration spacer and forms an electrical connection on the surface in which it is in contact, A piezoelectric micropump characterized by including a deformable piece provided on the other side of a vibrating spacer.

2. The piezoelectric micropump according to claim 1, characterized in that the vibration spacer is made of an elastic material.

3. The piezoelectric micropump according to claim 1, characterized in that the vibration spacer is a polyurethane thin film or a PET thin film, or the vibration spacer is made of a composite material of a polyurethane thin film and a metal sheet, or the vibration spacer is made of a composite material of a PET thin film and a metal sheet.

4. The piezoelectric micropump according to claim 1, wherein the vibration spacer has a pressure node portion in a planar region in close contact with the actuator, the pressure node portion exhibits an irregular annular shape, the pressure at the pressure node portion approaches zero, and the pressure on both sides of the pressure node portion is directed in opposite directions.

5. The piezoelectric micropump according to claim 1, characterized in that the check valve is a thin-film valve with a pressure release function.

6. The aforementioned check valve is, A separator, wherein the separator has a valve region and an exhaust region that penetrate both its upper and lower ends, the exhaust region is provided next to the valve region, and the exhaust region communicates with the valve region via a communication region, A plate, comprising two plates, the two plates being positioned above and below the separator, with corresponding first holes vertically penetrating each plate at positions in the valve region, and a third hole vertically penetrating each plate at positions in the exhaust region. A piezoelectric micropump according to claim 1 or 5, comprising a membrane, wherein the membrane is installed between a separator and one of the plates, and corresponding second holes are opened vertically through the membrane and one of the plates at positions located in the valve region, and the second holes are offset from the first holes.

7. The piezoelectric micropump according to claim 1, characterized in that the actuator is manufactured from a piezoelectric material.

8. The piezoelectric micropump according to claim 1 or 7, characterized in that the actuator is one of a rectangular actuator, a polygonal actuator, or a circular actuator.

9. Electrodes are arranged on each of the two upper and lower surfaces of the actuator, and multiple electrodes are installed on the surface of the actuator that is in close contact with the vibration spacer, forming an electrical connection with the multiple electrodes of the vibration spacer. The piezoelectric micropump according to claim 8, characterized in that an annular electrode is installed on the outside of the surface of the actuator that is in contact with the vibration spacer, and the annular electrode communicates with an electrode on the other side of the actuator via an electrical connection portion on the side.

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