CN118327943A

CN118327943A - A piezoelectric micro pump

Info

Publication number: CN118327943A
Application number: CN202410583505.9A
Authority: CN
Inventors: 林汉记; 张四海
Original assignee: Xiamen Micro Energy Electronic Technology Co ltd
Current assignee: Xiamen Micro Energy Electronic Technology Co ltd
Priority date: 2024-05-11
Filing date: 2024-05-11
Publication date: 2024-07-12
Also published as: WO2025236739A1

Abstract

The invention provides a piezoelectric micropump, which comprises a pump body, a piezoelectric pump and a piezoelectric pump, wherein the pump body is provided with a square cavity; the vibration isolation sheet is horizontally arranged in the middle of the square cavity, the square cavity is divided into an upper independent cavity and a lower independent cavity, two holes are respectively formed in the end walls of the upper cavity and the lower cavity in a penetrating mode, and one hole is formed in the middle of the end wall of the cavity; the one-way valve is arranged on one hole of the cavity; an actuator attached to one of the surfaces of the vibration isolation sheet and electrically connected to the attached surface; and a deformation sheet disposed on the other face of the vibration isolation sheet. 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 the larger fluid pressure and flow are brought.

Description

Piezoelectric micropump

Technical Field

The invention relates to the technical field of micropumps, in particular to a piezoelectric micropump.

Background

Piezoelectric micropumps are commonly used in portable electronic devices, such as portable blood pressure monitors, head-mounted massagers, etc., and are relatively small-sized pumps for delivering positive pressure or providing vacuum. In order to achieve the desired goals of small size, high efficiency, and silent operation, such pumps must operate at very high frequencies, typically about 20kHz or more. In order to operate at high frequencies, the valves with which the pump is equipped must respond to high frequency oscillating pressures that can be rectified to produce a net fluid flow through the pump.

The piezoelectric micropump in the prior art has the problem that the area of a vibration cavity is limited, and the braking area of an actuator is small, so that the vibration amplitude is insufficient, the formed gas pressure is small, and the fluid pressure and the fluid flow can be influenced, so that a new piezoelectric micropump is needed to solve some problems in the prior art.

Disclosure of Invention

The present invention is directed to a piezoelectric micropump that solves some of the problems of the prior art.

In order to achieve the above purpose, the invention adopts the following technical scheme: a piezoelectric micropump, comprising:

A pump body with a square cavity;

The vibration isolation sheet is horizontally arranged in the middle of the square cavity, the square cavity is divided into an upper independent cavity and a lower independent cavity, two holes are respectively formed in the end walls of the upper cavity and the lower cavity in a penetrating mode, and one hole is formed in the middle of the end wall of the cavity;

The one-way valve is arranged on one hole of the cavity;

An actuator attached to one of the surfaces of the vibration isolation sheet and electrically connected to the attached surface;

and a deformation sheet disposed on the other face of the vibration isolation sheet.

Further, the vibration isolation sheet is made of elastic materials.

Further, the vibration isolation sheet is made of a polyurethane film or a PET film, or is made of a composite material of the polyurethane film and a metal sheet, or is made of a composite material of the PET film and the metal sheet.

Further, the planar area where the vibration isolation sheet is attached to the actuator is provided with a pressure node, the pressure node is irregularly annular, the pressure at the pressure node tends to be zero, and the pressures at two sides of the pressure node are opposite.

Further, the one-way valve is a film valve with a pressure relief function.

Further, the check valve includes:

the spacer is provided with a valve area and a gas leakage area which penetrate through the upper end and the lower end of the spacer, the gas leakage area is arranged beside the valve area, and the gas leakage area is communicated with the valve area through a communication area;

The two plates are respectively arranged on the upper side and the lower side of the spacer, the positions of the two plates in the valve area are respectively and vertically penetrated with corresponding first holes, and the positions of the two plates in the air leakage area are vertically penetrated with third holes;

The valve is arranged between the spacer and the plate provided with the third hole, the valve and the plate provided with the third hole are respectively and vertically penetrated by corresponding second holes at the positions of the valve area, and the second holes are deviated from the first holes.

Further, the actuator is made of piezoelectric material.

Further, the actuator is any one of a square actuator, a polygonal actuator, or a circular actuator.

Further, electrodes are respectively arranged on the upper surface and the lower surface of the actuator, a plurality of electrodes are arranged on the joint surface of the actuator and the vibration isolation sheet, and the electrodes are electrically connected with the vibration isolation sheet;

The annular electrode is communicated with the electrode on the other surface of the actuator through a side edge electric connection part.

After the technical scheme is adopted, compared with the prior art, the method has the following beneficial effects: the square cavity can provide a larger braking area for the actuator, thereby bringing about an increase in vibration amplitude, so that the formed gas pressure is increased, and larger fluid pressure and flow are brought about.

Drawings

In order to more clearly illustrate the embodiments of the invention or the technical solutions of the prior art, the drawings which are used in the description of the embodiments or the prior art will be briefly described, it being obvious that the drawings in the description below are only some embodiments of the invention, and that other drawings can be obtained according to these drawings without inventive faculty for a person skilled in the art.

FIG. 1 is a schematic diagram of the structure of the present invention;

FIG. 2 is a schematic diagram of an exploded construction of the present invention;

FIG. 3 is a schematic view of a partial structure of the present invention;

fig. 4 is a partial structural schematic diagram of the vibration isolation sheet 2 in the present invention;

FIG. 5 is a pressure map of the present invention;

Fig. 6 is a partial schematic view of the actuator 4 of the present invention in a square shape;

Fig. 7 is a partial schematic structural view of the actuator 4 of the present invention in a polygonal shape;

fig. 8 is a partial schematic structural view of the actuator 4 of the present invention when it is circular;

fig. 9 is a schematic view showing one of the structures of the single valve 3 in the present invention;

FIG. 10 is a schematic view of a partial structure of the valve 34 of the present invention in engagement with the second plate 33;

FIG. 11 is a partial schematic view of the valve 34 of the present invention in engagement with the first plate 32;

Fig. 12 is a schematic view of another structure of the single-plate valve 3 according to the present invention.

Reference numerals illustrate: 1. a pump body; 11. an upper pump shell; 12. a lower pump shell; 13. an upper cavity; 14. a lower cavity; 141. a fourth hole; 142. a fifth hole; 15. an air outlet hole; 16. a vent hole; 2. a vibration isolation sheet; 21. electrically connecting the input end; 22. a pressure node; 3. a one-way valve; 31. a spacer; 311. a baffle; 312. a valve region; 313. a venting area; 314. a communication region; 32. a first plate; 33. a second plate; 34. a valve; 35. a first hole; 36. a second hole; 37. a third hole; 4. an actuator; 41. a ring electrode; 411. the side edge electric connection part; 42. a circular electrode; 5. deformation sheet.

Detailed Description

The present invention will be described in further detail with reference to the following examples in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.

In view of the problems of the prior art, the present invention provides a piezoelectric micropump, and the present invention is described in detail below with reference to the accompanying drawings.

Referring to fig. 1 to 11, the technical scheme adopted in this embodiment is as follows: the piezoelectric micropump comprises a pump body 1, a vibration isolation sheet 2, a one-way valve 3, an actuator 4 and a deformation sheet 5, wherein the pump body 1 comprises 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 containing fluid, and the ratio between the side length and the height of the cavity is larger than 2.5.

The middle position of the cavity is provided with a vibration isolation sheet 2, the square cavity or the approximately square cavity is separated by the vibration isolation sheet 2 to form an upper cavity 13 and a lower cavity 14, and the two cavities are independent. Specifically, the vibration isolation sheet 2 has a generally square structure, and the edges thereof are pressed against the casing ends of the upper and lower pump casings 11, 12 to divide the cavity into upper and lower independent portions. One side of the vibration isolation sheet 2 extends to the outside of the pump body 1 to form a thin strip body, and the tail end of the thin strip body is an electric connection input end 21.

It should be specifically noted that, the center positions of the end walls of the upper cavity 13 and the lower cavity 14 are respectively penetrated with a fourth hole 141, and the end walls of the upper cavity 13 and the lower cavity 14 are respectively penetrated with a fifth hole 142, and the fifth holes 142 are arranged at any positions of the end walls except the positions of the fourth holes 141. A one-way valve 3 is mounted in one of the fourth 141 or fifth 142 apertures to enable fluid to flow through the cavity in use.

The vibration isolation sheet 2 is arranged between the actuator 4 and the deformation sheet 5, and the abutting surface of the actuator 4 and the vibration isolation sheet 2 is electrically connected. 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 sheet 2, and the actuator 4 and the two electrodes or more electrodes of the vibration isolation sheet 2 are electrically connected on the bonding surface.

Wherein, an annular electrode 41 is arranged outside the joint surface of the actuator 4 and the vibration isolation sheet 2, the annular electrode 41 is communicated with the electrode on the other surface of the actuator 4 through a side edge electric connection 411, and the annular electrode 41 is electrically contacted with at least one of a plurality of conductive tracks of the vibration isolation sheet 2. At this time, the actuator 4 is provided with a circular electrode 42 inside the ring electrode 41.

Preferably, the actuator 4 is made of piezoelectric material, and may be a square actuator, an approximately square actuator, a polygonal actuator or a circular actuator. After the 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 is integrally bonded with the vibration isolation sheet 2 and the deformation sheet 5, so that the deformation sheet 5 expands or contracts in the actuator 4 to deform, and the deformation sheet 5 drives the vibration isolation sheet 2 to vibrate by inputting an alternating voltage to the actuator 4.

Preferably, the vibration isolation sheet 2 is made of a material with elastic characteristics, such as a polyurethane film, a PET film, or a composite material of a polyurethane film or a PET film and a metal sheet.

As shown in fig. 5, the actuator 4 and the deformation sheet 5 generate waveform vibration under the action of an alternating electric field, a pressure node 22 exists in the plane area where the vibration isolation sheet 2 is attached to the actuator 4, the pressure node 22 presents an irregular ring shape, the pressure tends to be zero, the pressures on two sides of the pressure node 22 are opposite, and two wave crest areas are formed, one inside the pressure node 22 and the other outside the pressure node 22, and fluid is driven to flow unidirectionally under the action of pressure.

The driving frequency of the actuator 4 shown exceeds 20KHz and the effect of the vibrations is near silence outside the area that can be perceived by the hearing of the human ear.

Preferably, the one-way valve 3 is a one-way valve with a pressure relief function, has both air outlet and pressure relief functions, can solve the problem that the existing piezoelectric micropump does not have the pressure relief function, so that the application equipment needs to be independently provided with a pressure relief valve, can well save the internal space of the application equipment, reduce the volume of the equipment and the cost, and is more convenient to use.

Specifically, the one-way valve 3 includes a spacer 31, a first plate 32, a second plate 33, and a valve 34, where the spacer 31 has a hollow area extending longitudinally through the upper and lower ends of the spacer, and a baffle 311 horizontally extends in the hollow area to partition the hollow area into a valve area 312 and a venting area 313, and the valve area 312 is communicated with the venting area 313 through a communication area 314. The first plate 32 and the second plate 33 are respectively disposed on the upper and lower sides of the spacer 31, the positions of the first plate 32 and the second plate 33 in the valve area 312 are respectively and vertically perforated with a first hole 35, and the first hole 35 on the first plate 32 is correspondingly disposed with the first hole 35 on the second plate 33.

The valve 34 is disposed between the second plate 33 and the spacer 31, the second plate 33 and the valve 34 are vertically provided with second holes 36 respectively at positions of the valve area 312, the second holes 36 on the second plate 33 correspond to the second holes 36 on the valve 34, and the second holes 36 are offset from the first holes 35.

Specifically, the third hole 37 is vertically formed in the position of the second plate 33 in the air release area 313, and when the pump is in operation, 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 release hole 16 of the pump body are sequentially communicated to form an air release channel.

Specifically, the communication region 314 is disposed at an extension port of the baffle 311, and the area of the baffle 311 is larger than that of the communication region 314. Preferably, two baffles 311 are disposed between the valve area 312 and the air release area 313, and the two baffles 311 are disposed symmetrically with respect to each other, and the communication area 314 is disposed between opposite extending ports of the two baffles 311.

Preferably, the valve area 312 is disposed at the center of the spacer 31 and has an area larger than that of the air leakage area 313. The area of the venting area 313 is approximately one fifth the area of the valve area 312.

In addition, the valve area 312 may be a monolithic area or may be formed of areas that are interconnected in multiple pieces.

It should be noted that two venting areas 313 may be provided, and two venting areas 313 are symmetrically disposed at two opposite sides of the valve area 312. In practice, the number of specific arrangement of the air release areas 313 is not limited to one or two, and may be adjusted according to actual design requirements.

The check valve 3 is arranged in the pump body 1, when the actuator 4 works, vibration of the actuator 4 can bring about change of air flow pressure in the cavity, the check valve 3 vibrates up and down at the same frequency under the change of air pressure at two sides in synchronization with the input frequency, when the valve 34 is close to the second plate 33, the first hole 35 of the first plate 32 is communicated with the second hole 36 of the second plate 33, at the moment, the air pressure in the pump cavity is higher than that in the air passage, and the air pump is in an exhaust state; when the valve 34 is pressed against the first plate 32, the pressure in the air passage is higher than that in the pump cavity, the valve is in a closed state, and the air pump is in a stopped pumping state at the moment; at this time, since the up-and-down vibration of the valve 34 and the actuator are the same-frequency high-frequency motion, the motion time is very short, and at this time, the motion 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;

When the actuator 4 stops working, the pressure in the pump cavity is communicated with the outside, the pressure of the air outlet pipeline is longer than that of the pump cavity, the valve 34 is tightly attached to the first plate 32 in the central area, and in the peripheral air outlet hole 16 area, as the pressure of the air outlet pipeline cannot be relieved, air can overflow to the outer area through the air outlet hole 15 to enable the valve 34 to be tightly attached to the first plate 32, so that the third hole 37 is opened, the opening of the air outlet hole 16 is realized, and the air pressure in the air outlet pipeline is discharged through the air outlet hole 16;

When the actuator 4 is operated again, the pump chamber pressure is greater than the pressure in the air outlet pipe, the valve 34 will restore to close the third hole 37 under the pressure, and the high-frequency action air outlet state is restored.

As shown in fig. 12, the valve 34 of the single valve 3 may be further disposed between the first plate 32 and the spacer 31, and in this case, the first plate 32 is vertically provided with a third hole 37 at a position of the relief area 313. In the presence of pressure on the end face of the first plate 32, the valve 34 closes a third hole 37 in the first plate 32, the third hole 37 being provided in the first plate 37 for pushing the valve 34 against the second plate 33 by means of air pressure.

The square or approximately square cavity can provide larger braking area for the actuator 4, so that the vibration amplitude is increased, the formed gas pressure is increased, larger fluid pressure and flow are brought, the air outlet and pressure relief functions are achieved, the application equipment does not need to be additionally and independently provided with a pressure relief valve, the internal space of the application equipment can be well saved, the equipment volume is reduced, the cost is reduced, the use is convenient, and the popularization and application values are very high.

In the description of the present invention, unless otherwise indicated, the meaning of "a plurality" is two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front," "rear," "head," "tail," and the like are used as an orientation or positional relationship based on that shown in the drawings, merely to facilitate description of the invention and to simplify the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the invention. Furthermore, the terms "first," "second," "third," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

The foregoing is merely illustrative of the present invention and not restrictive, and other modifications and equivalents thereof may occur to those skilled in the art without departing from the spirit and scope of the present invention.

Claims

1. A piezoelectric micropump, comprising:

A pump body with a square cavity;

The one-way valve is arranged on one hole of the cavity;

2. The piezoelectric micropump of claim 1, wherein the vibration isolation sheet is made of an elastic material.

3. The piezoelectric micropump of claim 1, wherein the vibration isolation sheet is a polyurethane film or a PET film, or the vibration isolation sheet is made of a composite material of a polyurethane film and a metal sheet, or the vibration isolation sheet is made of a composite material of a PET film and a metal sheet.

4. The piezoelectric micropump of claim 1, wherein the planar area of the vibration isolation plate attached to the actuator has a pressure node, the pressure node is irregularly annular, the pressure at the pressure node tends to be zero, and the pressures at both sides of the pressure node are opposite.

5. The piezoelectric micropump of claim 1, wherein the one-way valve is a membrane valve with a pressure relief function.

6. The piezoelectric micropump of any one of claims 1 or 5, wherein the one-way valve comprises:

the two plates are respectively arranged on the upper side and the lower side of the spacer, the positions of the two plates in the valve area are respectively and vertically penetrated with corresponding first holes, and the positions of the plates in the air leakage area are vertically penetrated with third holes;

the valve is arranged between the spacer and any plate, corresponding second holes are respectively and vertically formed in the positions of the valve and one plate in the valve area in a penetrating mode, and the second holes are arranged in a deviating mode from the first holes.

7. The piezoelectric micropump of claim 1, wherein the actuator is made of a piezoelectric material.

8. The piezoelectric micropump of any one of claims 1 or 7, wherein the actuator is any one of a square actuator, a polygonal actuator, or a circular actuator.

9. The piezoelectric micropump of claim 8, wherein 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 sheet and electrically connected with the plurality of electrodes of the vibration isolation sheet;