CN116857157A - Valveless piezoelectric micropump - Google Patents

Abstract

The invention provides a valveless piezoelectric micropump, comprising: the base body is provided with a fluid inlet, a flow channel and a fluid outlet; at least two flow-blocking elements, each flow-blocking element being located in the flow passage, each flow-blocking element being capable of generating a first flow resistance along a fluid from the fluid outlet to the fluid inlet; two diaphragms, each diaphragm and the flow channel forming a pump cavity, one of the two diaphragms being located between the fluid inlet and the flow blocking member adjacent to the fluid inlet, the other of the two diaphragms being located between the two flow blocking members; and the control element is respectively connected with the two diaphragms and used for controlling each diaphragm to move towards or away from the base body so as to increase or decrease the volume of the corresponding pump cavity. The valveless piezoelectric micropump provided by the embodiment of the invention not only can reduce the reflux quantity of the fluid, is beneficial to the directional flow of the fluid in the flow channel, but also can realize larger pumping quantity of the fluid and improve the flow quantity of the conveyed fluid.

Description

Valveless piezoelectric micropump

Technical Field

The invention relates to the technical field of fluid systems, in particular to a valveless piezoelectric micropump.

Background

Micropump is the core component of the microfluidic system, and its performance directly determines the performance of the microfluidic system. The moving parts of a micropump are typically an actuation part and a microvalve membrane or flap. Micropumps can generate a driving force by using piezoelectric, electrostatic, thermopneumatic, pneumatic, or magnetic effects.

Piezoelectric micropumps are a common type of reciprocating diaphragm pump. The vibration of the piezoelectric ceramic plate is realized by the inverse piezoelectric effect of the piezoelectric ceramic, so that the volume of the pump cavity is changed, and the purpose of conveying fluid is achieved. The piezoelectric micropump has the advantages of compact structure, small volume, quick response, no influence of electromagnetic interference and the like, and is widely applied to a plurality of different fields of chemistry, biomedicine, liquid cooling and fuel supply.

Piezoelectric micropumps can be classified into valved micropumps and valveless micropumps; the valved micropump realizes the directional flow of fluid through opening and closing of the check valve; the suction and pumping of the valveless micropump to the liquid are realized mainly by the pressure loss difference of the shrink tube/expansion tube, and the valveless micropump has simpler structure, higher reliability, longer service life and easier manufacture due to the absence of a check valve.

For the existing valveless micropump, when the fluid is conveyed, the directional flow of the fluid is difficult to realize, the larger outlet back pressure of the fluid is difficult to realize, the flow rate of the conveyed fluid is also smaller, and the flow rate is slower.

Disclosure of Invention

The invention aims to provide a novel technical scheme of a valveless piezoelectric micropump, which can solve at least one of the technical problems that the valveless pump in the prior art is difficult to realize directional flow of fluid, is difficult to realize larger outlet back pressure of the fluid, is smaller in flow rate of the conveyed fluid, is slower in flow rate and the like.

According to an object of the present invention, there is provided a valveless piezoelectric micropump comprising: the base body is provided with a fluid inlet, a flow channel and a fluid outlet, a first end of the flow channel is communicated with the fluid inlet, and a second end of the flow channel is communicated with the fluid outlet; at least two flow-blocking members spaced apart in a direction of fluid flow from said fluid inlet to said fluid outlet, each of said flow-blocking members being located in said flow path, each of said flow-blocking members being capable of generating a first flow resistance to fluid along the direction from said fluid outlet to said fluid inlet and a second flow resistance to fluid along the direction from said fluid inlet to said fluid outlet, said first flow resistance being greater than said second flow resistance to permit fluid to enter from said fluid inlet and exit from said fluid outlet; two diaphragms spaced apart in a fluid flow direction from the fluid inlet to the fluid outlet, each diaphragm and the flow passage forming a pump chamber, one of the two diaphragms being located between the fluid inlet and the flow blocking member adjacent to the fluid inlet, the other of the two diaphragms being located between the two flow blocking members; and the control element is respectively connected with the two diaphragms, and is used for controlling each diaphragm to move towards or away from the matrix so as to increase or decrease the volume of the corresponding pump cavity.

Optionally, the flow channel includes: the two side walls are distributed at intervals and are arranged oppositely, each side wall is connected with the bottom wall, at least one side wall comprises a first section body, a second section body and a third section body which are sequentially connected along the fluid flow direction from the fluid inlet to the fluid outlet, the flow blocking piece is arranged on the bottom wall, the curvature of a part, corresponding to the third section body, of the side wall surface of the flow blocking piece is larger than that of the third section body, and the distance between the side wall surface of the flow blocking piece and the second section body is larger than that between the side wall surface of the flow blocking piece and the third section body.

Optionally, the distance between the side wall surface of the flow blocking piece and the first section is smaller than the distance between the side wall surface of the flow blocking piece and the second section.

Optionally, along the fluid flow direction from the fluid inlet to the fluid outlet, a portion of the side wall surface of the flow blocking piece corresponding to the fluid outlet is provided with an inward concave groove body.

Optionally, the flow channel includes a first fluid channel and a second fluid channel that are mutually communicated, one of the flow blocking pieces is respectively disposed in the first fluid channel and the second fluid channel, and the substrate includes: the first plate body and the second plate body are mutually stacked, the first plate body is provided with the fluid outlet and the first fluid channel, and the second plate body is provided with the fluid inlet and the second fluid channel and simultaneously corresponds to the two vibrating membranes.

Optionally, the first fluid channel comprises: the first groove is formed in one side, close to the second plate body, of the first plate body, and the flow blocking piece is arranged in the first groove.

Optionally, the second fluid channel comprises: the second groove is formed in one side, far away from the first plate body, of the second plate body, the flow blocking piece is arranged in the second groove, and the second groove corresponds to the two vibrating membranes at the same time.

Optionally, the second groove includes: a first opening and a second opening which are spaced apart in a fluid flow direction from the fluid inlet to the fluid outlet, the first opening corresponding to one of the diaphragms, the second opening corresponding to the other diaphragm; a first slot, a first end of the first slot in communication with the first opening; the first end of the second groove is communicated with the second end of the first groove, and the flow blocking piece is arranged in the second groove; a third slot, a first end of the third slot in communication with a second end of the second slot, the second end of the third slot in communication with the second opening; wherein the radial dimension of the first opening is greater than the radial dimension of the first slot and/or the radial dimension of the second opening is greater than the radial dimension of the third slot.

Optionally, the second fluid channel further comprises: the communication hole penetrates through the second plate body in the thickness direction, the first end of the communication hole is communicated with the second groove in the stacking direction from the second plate body to the first plate body, the second end of the communication hole is communicated with the first fluid channel, and the radial size of the first end of the communication hole is smaller than that of the second end of the communication hole.

Optionally, the number of flow-blocking pieces is plural, and the number of flow-blocking pieces between two of the diaphragms is smaller than the number of flow-blocking pieces between the diaphragms and the fluid outlet.

Optionally, the control element is a piezoelectric sheet, and the piezoelectric sheet is adhered to one side of the vibrating membrane away from the substrate.

According to the valveless piezoelectric micropump provided by the embodiment of the invention, the matrix, at least two flow choking pieces, two vibrating membranes and the control element are combined, so that the backflow amount of fluid can be reduced, the directional flow of the fluid in a flow passage is facilitated, the larger pumping amount of the fluid can be realized, and the flow rate of the conveyed fluid is improved.

Other features of the present invention and its advantages will become apparent from the following detailed description of exemplary embodiments of the invention, which proceeds with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of the invention.

FIG. 1 is a cross-sectional view of a valveless piezoelectric micropump according to one embodiment of the present invention;

FIG. 2 is an exploded view of a valveless piezoelectric micropump according to one embodiment of the present invention;

FIG. 3 is a schematic structural view of a second plate according to one embodiment of the present invention;

fig. 4 is a schematic perspective view of a first plate according to an embodiment of the present invention;

FIG. 5 is a top view of a first plate according to one embodiment of the invention;

FIG. 6 is a flow schematic of a fluid moving in a positive flow direction according to one embodiment of the invention;

FIG. 7 is a schematic flow diagram of fluid moving in a reverse flow direction according to one embodiment of the invention;

fig. 8 is a schematic diagram of input signals to a control element according to one embodiment of the invention.

Reference numerals

Valveless piezoelectric micropump 100;

a base body 10;

a fluid inlet 11; a fluid outlet 12;

a flow channel 13;

a bottom wall 131;

a sidewall 132; a first segment 1321; a second segment 1322; a third segment 1323;

a first plate 14; a first fluid channel 141;

a second plate 15;

a second fluid channel 151;

a second groove 1511; a first opening 15111; a second opening 15112; a first slot 15113; a second slot 15114; third slot 15115; first pump chamber 15116; a second pump chamber 15117;

a communication hole 1512;

a choke 20; a tank body 21; a first flow blocking member 22; a second flow blocking member 23;

a diaphragm 30; a first diaphragm 31; a second diaphragm 32;

a control element 40;

a protective shell 50;

sealing pressure plate 60.

Detailed Description

Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that: the relative arrangement of the components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless it is specifically stated otherwise.

The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.

Techniques, methods, and apparatus known to one of ordinary skill in the relevant art may not be discussed in detail, but are intended to be part of the specification where appropriate.

In all examples shown and discussed herein, any specific values should be construed as merely illustrative, and not a limitation. Thus, other examples of exemplary embodiments may have different values.

It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further discussion thereof is necessary in subsequent figures.

The valveless piezoelectric micropump 100 according to an embodiment of the present invention is described in detail below with reference to specific embodiments.

As shown in fig. 1 to 8, the valveless piezoelectric micropump 100 according to the embodiment of the present invention includes a substrate 10, at least two spoilers 20, two diaphragms 30, and a control element 40.

Specifically, the base 10 is provided with a fluid inlet 11, a flow channel 13 and a fluid outlet 12, a first end of the flow channel 13 is communicated with the fluid inlet 11, a second end of the flow channel 13 is communicated with the fluid outlet 12, two flow chokes 20 are distributed at intervals along the fluid flow direction from the fluid inlet 11 to the fluid outlet 12, each flow choking 20 is positioned in the flow channel 13, each flow choking 20 can generate a first flow resistance to the fluid along the fluid from the fluid outlet 12 to the fluid inlet 11 and generate a second flow resistance to the fluid along the fluid from the fluid inlet 11 to the fluid outlet 12, and the first flow resistance is larger than the second flow resistance so that the fluid enters from the fluid inlet 11 and flows out from the fluid outlet 12.

Two diaphragms 30 are spaced apart in the fluid flow direction from the fluid inlet 11 to the fluid outlet 12, each diaphragm 30 forming a pump chamber with the flow channel 13, one of the two diaphragms 30 being located between the fluid inlet 11 and the flow-blocking member 20 adjacent to the fluid inlet 11, the other of the two diaphragms 30 being located between the two flow-blocking members 20.

The control element 40 is connected to the two diaphragms 30 for controlling the movement of each diaphragm 30 towards or away from the base body 10 to increase or decrease the volume of the corresponding pump chamber. The control element 40 can control the two diaphragms 30 to vibrate simultaneously or alternately, so as to realize the flow rate of the fluid and the output of the large pump pressure.

In other words, the valveless piezoelectric micropump 100 according to the embodiment of the present invention is mainly composed of a substrate 10, at least two flow blocking members 20, two diaphragms 30, and a control element 40, wherein the substrate 10 is provided with a fluid inlet 11, a fluid channel 13, and a fluid outlet 12, respectively, and the fluid channel 13 communicates with the fluid inlet 11 and the fluid outlet 12, that is, fluid can flow into the fluid channel 13 through the fluid inlet 11 and then flow out of the fluid channel 13 through the fluid outlet 12.

At least two flow-blocking elements 20 are provided in the flow channel 13, the two flow-blocking elements 20 being spaced apart in the direction of fluid flow from the fluid inlet 11 to the fluid outlet 12. For example, the fluid flow direction from the fluid inlet 11 to the fluid outlet 12 is defined as a forward flow direction, and the fluid flow direction from the fluid outlet 12 to the fluid inlet 11 is defined as a reverse flow direction. At this time, at least two flow blocking pieces 20 are distributed in the flow channel 13, each flow blocking piece 20 can generate a first flow resistance to the fluid along the direction from the fluid outlet 12 to the fluid inlet 11, and generate a second flow resistance to the fluid along the direction from the fluid inlet 11 to the fluid outlet 12, wherein the first flow resistance is larger than the second flow resistance, that is, the fluid in the flow channel 13 receives the second flow resistance generated by the flow blocking piece 20 when flowing along the positive flow direction, the fluid in the flow channel 13 receives the first flow resistance generated by the flow blocking piece 20 when flowing along the reverse flow direction, the first flow resistance is larger, the second flow resistance is smaller, or even zero, so that the state of the local fluid in the flow channel 13 flowing along the reverse flow direction can be effectively lightened, the effect of the whole fluid flowing from the fluid inlet 11 in the flow channel 13 is beneficial to realizing the unidirectional flow of the fluid flowing out of the fluid outlet 12, the circulation efficiency of the valveless piezoelectric micropump 100 is improved, the performance of the valveless micropump 100 is more stable, and the service life is longer. And the flow resistance in the reverse flow direction can be changed by being favorable for unidirectional flow, the reverse flow amount of the fluid is reduced, and the larger pumping amount of the fluid is realized.

Also, two diaphragms 30 are provided in the positive flow direction, each diaphragm 30 being capable of forming a pump chamber with a portion of the flow passage 13, that is, one diaphragm 30 forming one pump chamber with the flow passage 13 and the other diaphragm 30 forming the other pump chamber with the further portion of the flow passage 13. And, one of the two diaphragms 30 is located between the fluid inlet 11 and the flow blocking member 20 near the fluid inlet 11, and the other of the two diaphragms 30 is located between the two flow blocking members 20.

Each diaphragm 30 is movable toward and away from the base 10 to increase or decrease the volume of the corresponding pump chamber, which is advantageous for controlling the condition of the fluid in the flow channel 13 by changing the volume of the pump chamber, e.g. controlling the flow of fluid from the fluid inlet 11 into the flow channel 13, controlling the flow of fluid from one pump chamber to another, etc.

For convenience of explanation, two pump chambers are defined as a first pump chamber 15116 and a second pump chamber 15117, and two diaphragms 30 are defined as a first diaphragm 31 and a second diaphragm 32. And defines two spoilers 20 as a first spoiler 22 and a second spoiler 23.

Wherein, the periphery of the first vibration film 31 can be attached to the outer edge of the first pump chamber 15116, and the periphery of the second vibration film 32 can be attached to the outer edge of the second pump chamber 15117. First pump chamber 15116 is closer to fluid inlet 11 than second pump chamber 15117, first pump chamber 15116 may be positioned between fluid inlet 11 and first flow-blocking member 22, and second pump chamber 15117 may be positioned between first flow-blocking member 22 and second flow-blocking member 23.

When either diaphragm 30 bulges to increase the volume of the pump chamber, suction can be created in the pump chamber to introduce fluid into the pump chamber, as will be appreciated, during fluid introduction, if it is desired to pass through the flow resistor 20, fluid introduction in that direction will be effected. When any diaphragm 30 is compressed to reduce the volume of the pump chamber, the principle of pressure difference can be used to compress the fluid in the pump chamber to other pump chambers or other positions in the flow channel 13, and likewise, during the process of leading the fluid out of the pump chamber, if the fluid passes through the flow blocking piece 20, the fluid leading out in the direction can be influenced.

Specifically, the first pump chamber 15116 may be located between the fluid inlet 11 and the first flow blocking member 22, the second pump chamber 15117 may be located between the first flow blocking member 22 and the second flow blocking member 23, that is, the first diaphragm 31 is located between the fluid inlet 11 and the first flow blocking member 22, and the second diaphragm 32 is located between the first flow blocking member 22 and the second flow blocking member 23, so that the pressing and swelling of the first diaphragm 31 and the second diaphragm 32, respectively, can be controlled, and the unidirectional flow of the fluid in the flow passage 13 can be achieved even when the partial reflux occurs. That is, a portion of the flow path 13 corresponding to the first diaphragm 31 may be formed as a first pump chamber 15116, a portion of the flow path 13 corresponding to the second diaphragm 32 may be formed as a second pump chamber 15117, and a first choke member 22 may be provided between the first pump chamber 15116 and the second pump chamber 15117.

For example, the control element 40 applies an electric signal of the same frequency to the first diaphragm 31 and the second diaphragm 32. When the first diaphragm 31 and the second diaphragm 32 vibrate downward simultaneously, the first diaphragm 31 can squeeze the first pump chamber 15116, the second diaphragm 32 can squeeze the second pump chamber 15117, at this time, the squeezing of the first diaphragm 31 and the first flow blocking member 22 between the first pump chamber 15116 and the second pump chamber 15117 are beneficial to ensure that the fluid in the second pump chamber 15117 does not flow back into the first pump chamber 15116, but only flows to the second flow blocking member 23, and the fluid in the positive flow direction is less or not blocked due to the greater resistance of the second flow blocking member 23 to the fluid, so that the fluid in the second pump chamber 15117 passes through the second flow blocking member 23 and finally flows out through the fluid outlet 12.

When first diaphragm 31 and second diaphragm 32 vibrate simultaneously upward, the volume of both first pump chamber 15116 and second pump chamber 15117 increases, and fluid may flow into first pump chamber 15116 and second pump chamber 15117 through fluid inlet 11. At this time, the fluid between the fluid outlet 12 and the second pump chamber 15117 is also returned by the pressure, and the backflow resistance of the fluid is increased due to the blocking of the second flow blocking piece 23 during the backflow process, so that the flow rate of the fluid flowing back into the second pump chamber 15117 is far smaller than the flow rate of the fluid flowing into the first pump chamber 15116 through the fluid inlet 11, and the fluid in the valveless piezoelectric micropump can realize directional flow.

For another example, as shown in fig. 8, control element 40 applies electrical signals of different frequencies to first diaphragm 31 and second diaphragm 32, and during a first time period (time t0-t 1), first diaphragm 31 and second diaphragm 32 vibrate simultaneously downward, first pump chamber 15116, while delivering fluid to second pump chamber 15117, prevents fluid within second pump chamber 15117 from flowing back to first pump chamber 15116 via first choke 22, ensuring that fluid within second pump chamber 15117 can be output through fluid outlet 12. During the second time period (time t1-t 2), first diaphragm 31 and second diaphragm 32 vibrate simultaneously upward, and the flow rate of fluid inlet 11 into first pump chamber 15116 is substantially greater than the return flow rate of second pump chamber 15117 into first pump chamber 15116 due to first flow resistor 22 between second pump chamber 15117 and first pump chamber 15116. During a third time period (time t2-t 3), second diaphragm 32 continues to vibrate upward, as first diaphragm 31 moves downward, delivering fluid from first pump chamber 15116 into second pump chamber 15117. In the fourth period (time t3-t 4), the second diaphragm 32 vibrates downward from the highest point, and at this time, the first diaphragm 31 vibrates upward rapidly, so that the fluid in the fluid inlet 11 can be sucked into the first pump chamber 15116 and circulated reciprocally.

In addition, the number of the diaphragms 30 is plural in the embodiment of the present invention, and the pumping amount of the fluid can be improved. When the number of the diaphragms 30 is two, the valveless piezoelectric micropump 100 of the embodiment of the present invention may be a dual diaphragm valveless piezoelectric micropump.

Therefore, the valveless piezoelectric micropump 100 according to the embodiment of the present invention adopts the combination of the substrate 10, at least two flow blocking members 20, two diaphragms 30 and the control element 40, so that the backflow amount of the fluid can be reduced, the directional flow of the fluid in the flow channel 13 is facilitated, the larger pumping amount of the fluid can be realized, the flow rate of the conveyed fluid is improved, and the larger outlet back pressure of the fluid is realized.

According to an embodiment of the present invention, as shown in fig. 3, the flow channel 13 includes a bottom wall 131 and two side walls 132, the two side walls 132 are spaced apart and disposed opposite to each other, each side wall 132 is connected to the bottom wall 131, along a fluid flow direction from the fluid inlet 11 to the fluid outlet 12, as shown in fig. 6 and 7, at least one side wall 132 includes a first segment 1321, a second segment 1322 and a third segment 1323 connected in sequence, the choke 20 is disposed on the bottom wall 131, a curvature of a portion of a side wall surface 21 of the choke 20 corresponding to the third segment 1323 is greater than a curvature of the third segment 1323, and a distance between the side wall surface 21 of the choke 20 and the second segment 1322 is greater than a distance between the side wall surface 21 of the choke 20 and the third segment 1323.

In other words, the inner surface of the flow channel 13 may include a bottom wall 131 and two side walls 132, the two side walls 132 are spaced apart and disposed opposite each other, and each side wall 132 is connected to the bottom wall 131. For example, the bottom wall 131 extends in the horizontal direction to the left and right, the side walls 132 are delayed in the up and down direction, and the two side walls 132 are spaced apart in the front and rear direction; alternatively, the bottom wall 131 extends in the up-down direction, the side walls 132 are elongated in the up-down direction, and the two side walls 132 are spaced apart in the left-right direction.

Along the positive flow direction, the at least one side wall 132 includes a first segment 1321, a second segment 1322, and a third segment 1323 that are sequentially connected, and a curvature of a portion of the side wall surface 21 of the choke 20 corresponding to the third segment 1323 is greater than a curvature of the third segment 1323, so that a coanda effect, or a coanda effect, can be formed between the side wall surface 21 of the choke 20 and the third segment 1323. For example, as shown in FIG. 6, when fluid flows in a positive flow direction and past the sidewall surface 21 of the flow resistor 20, a coanda effect can be created, and fluid can flow along the sidewall surface 21 of the flow resistor 20 with less or no resistance of the flow resistor 20. As shown in fig. 7, the distance between the side wall surface 21 of the choke 20 and the second segment 1322 is larger than the distance between the side wall surface 21 of the choke 20 and the third segment 1323, so that the vortex is formed at the second segment 1322 on the basis of the wall attaching effect, and the resistance of the fluid flowing back along the reverse flowing direction is increased. Wherein the direction of the arrow in the flow channel 13 in fig. 6 and 7 is the general flow direction of the fluid.

In some embodiments of the invention, as shown in fig. 6 and 7, the spacing between the sidewall surface 21 of the flow resistor 20 and the first segment 1321 is less than the spacing between the sidewall surface 21 of the flow resistor 20 and the second segment 1322. That is, the sectional area of the flow passage at the first stage 1321 is reduced, and the region C in the drawing causes an increase in pressure loss, which is advantageous in increasing the flow resistance of the fluid and reducing the flow rate of the fluid flowing back in the reverse flow direction.

According to an embodiment of the present invention, as shown in fig. 6 and 7, along the fluid flow direction from the fluid inlet 11 to the fluid outlet 12, the portion of the sidewall surface 21 of the flow blocking member 20 corresponding to the fluid outlet 12 is provided with an inwardly recessed groove 21. That is, when the fluid flows back in the reverse flow direction, the fluid may form a vortex shown in the area a at the position of the tank 21 due to the blocking of the inner wall of the tank 21, increasing the resistance to the backflow of the fluid.

For example, the positive flow direction is from top to bottom, the side wall 132 and the bottom wall 131 enclose a triangle-like or heart-like shaped groove, the upper end of the groove communicates directly or indirectly with the fluid inlet 11, the lower end of the groove communicates directly or indirectly with the fluid outlet 12, the cross-sectional area of the upper portion of the groove is larger than the cross-sectional area of the lower portion of the groove, and the area of the cross-sectional area of the groove near the upper end is substantially the B area. A groove body 21 is further arranged at the position of the flow blocking piece 20 corresponding to the lower end of the groove, and the area of the groove body 21 is approximately an area A. When the flow path is from top to bottom, as shown in fig. 6, the fluid may flow down the outer surface of the choke 20 due to the coanda effect, and the choke 20 may not perform a choke function. In contrast, as shown in fig. 7, when the fluid flows back in the reverse flow direction, that is, from the bottom to the top, the fluid may form a vortex in the region a due to the blocking of the tank 21, and the backflow resistance of the fluid is increased. In addition, when the fluid flows back, because the curvature of the outer side wall of the flow blocking piece 20 is larger, the fluid flows back along the outer side wall of the flow blocking piece 20 preferentially due to the coanda effect, and a vortex is formed at the region B, so that the resistance of the fluid flowing to the pump cavity is further increased. And, the cross section of the water outlet position C area at the upper end of the groove is reduced, resulting in an increase in pressure loss. That is, the flow direction and flow resistance of the fluid output or the back suction can be changed by utilizing the coanda effect of the fluid through the change of the shape of the flow blocking piece 20 and the design of the special-shaped flow channel 13, so that the back flow amount of the fluid can be reduced, and the larger pumping amount of the fluid can be realized.

In some embodiments of the present invention, as shown in fig. 1, the flow channel 13 includes a first fluid channel 141 and a second fluid channel 151 that are in communication with each other, one flow blocking member 20 is respectively disposed in the first fluid channel 141 and the second fluid channel 151, the base 10 includes a first plate 14 and a second plate 15, the first plate 14 and the second plate 15 are stacked on each other, the first plate 14 is provided with a fluid outlet 12 and the first fluid channel 141, and the second plate 15 is provided with a fluid inlet and the second fluid channel 151 and corresponds to two diaphragms 30 at the same time.

That is, the base body 10 may include a first plate body 14 and a second plate body 15, the first plate body 14 and the second plate body 15 being stacked on each other, for example, in a thickness direction, in which case the first plate body 14 may become a bottom plate, and the second plate body 15 may be referred to as a pump chamber plate. The first plate 14 is provided with a fluid outlet 12 and a first fluid channel 141, the second plate 15 is provided with a fluid inlet 11 and a second fluid channel 151 corresponding to the two diaphragms 30, and fluid can flow into the second fluid channel 151 from the fluid inlet 11, then can flow into the first fluid channel 141, and finally flows out from the fluid outlet 12. For example, the first plate 14 and the second plate 15 are stacked in the up-down direction, the first plate 14 is located below the second plate 15, the first fluid channel 141 is provided on the upper surface of the first plate 14, the second fluid channel 151 is provided on the upper surface of the second plate 15, and the fluid in the second fluid channel 151 can flow into the first fluid channel 141 substantially downward, so that the structural compactness between the first plate 14 and the second plate 15 can be improved, and the length of the flow channel 13 can be controlled.

In this embodiment, by adopting the combination of the first plate 14 and the second plate 15, the shape of the base 10 can be adjusted according to the space, and the flexibility is high.

According to one embodiment of the present invention, the first fluid channel 141 includes a first groove formed in a side of the first plate 14 adjacent to the second plate 15, and a choke 20 is disposed in the first groove. For example, the second plate 15 is located above the first plate 14, and the upper surface of the first plate 14 is provided with a first groove, and at least one second choke 23 is disposed in the first groove. In the present embodiment, by providing the first fluid passage 141 on the side of the first plate body 14 close to the second plate body 15, stacking of the first plate body 14 and the second plate body 15 in the thickness direction of the first plate body 14 is facilitated.

In some embodiments of the present invention, as shown in fig. 3, the second fluid channel 151 includes a second groove 1511, where the second groove 1511 is disposed on a side of the second plate 15 away from the first plate 14, the second groove 1511 is provided with a choke piece 20, and the second groove 1511 corresponds to two diaphragms 30 at the same time. For example, the second plate 15 is located above the first plate 14, a second groove 1511 is provided on the upper surface of the second plate 15, a choke 20 is provided in the second groove 1511, and one diaphragm 30 may be provided at the first end outer edge of the second groove 1511, and the other diaphragm 30 may be provided at the second end outer edge of the second groove 1511. In this embodiment, the second groove 1511 is formed on the side of the second plate 15 away from the first plate 14, which is favorable for controlling the respective pump chambers by the two diaphragms 30, for example, the two diaphragms 30 are mounted on the same side of the second plate 15, and the two control elements 40 are mounted on the same side of the second plate 15, so that the assembly difficulty is reduced and the structure is simplified.

According to one embodiment of the present invention, as shown in fig. 2 and 3, the second groove 1511 includes a first opening 15111, a second opening 15112, a first groove 15113, a second groove 15114, and a third groove 15115.

Specifically, the first opening 15111 and the second opening 15112 are spaced apart in a fluid flow direction from the fluid inlet 11 to the fluid outlet 12, the first opening 15111 corresponds to one diaphragm 30, the second opening 15112 corresponds to the other diaphragm 30, the first end of the first groove 15113 communicates with the first opening 15111, the first end of the second groove 15114 communicates with the second end of the first groove 15113, the choke 20 is provided in the second groove 15114, the first end of the third groove 15115 communicates with the second end of the second groove 15114, and the second end of the third groove 15115 communicates with the second opening 15112.

Wherein the radial dimension of the first opening 15111 is greater than the radial dimension of the first slot 15113, and/or the radial dimension of the second opening 15112 is greater than the radial dimension of the third slot 15115.

For example, second groove 1511 includes a first opening 15111, a second opening 15112, a first groove 15113, a second groove 15114, and a third groove 15115, first opening 15111 may correspond to first pump chamber 15116, and second opening 15112 may correspond to second pump chamber 15117. The second groove 15114 communicates with the first groove 15113 and the third groove 15115, respectively, and a first choke 22 is provided in the second groove 15114, i.e., a first choke 22 is provided between the first pump chamber 15116 and the second pump chamber 15117. The radial dimension of the first opening 15111 is larger than the radial dimension of the first groove 15113, or the radial dimension of the second opening 15112 is larger than the radial dimension of the third groove 15115, facilitating the installation of the larger-sized diaphragm 30. And, when the radial dimension of third groove 15115 is smaller than the radial dimension of second opening 15112, resistance to backflow of fluid in second pump chamber 15117 into first pump chamber 15116 is increased.

In this embodiment, by defining the second recess 1511 to include the first opening 15111, the second opening 15112, the first slot 15113, the second slot 15114, and the third slot 15115, and defining the dimensions and communication relationship, it is advantageous to mount two diaphragms 30 on the same side of the second plate 15, and to increase the resistance to backflow of fluid in the second pump chamber 15117 to the first pump chamber 15116, and to achieve directional flow of fluid in the flow channel 13.

In some embodiments of the present invention, as shown in fig. 1, the second fluid passage 151 further includes a communication hole 1512, the communication hole 1512 penetrating in a thickness direction of the second plate body 15, a first end of the communication hole 1512 communicating with the second groove 1511 in a stacking direction from the second plate body 15 to the first plate body 14, a second end of the communication hole 1512 communicating with the first fluid passage 141, a radial dimension of the first end of the communication hole 1512 being smaller than a radial dimension of the second end of the communication hole 1512.

That is, the second fluid passage 151 includes the second groove 1511 and the communication hole 1512, and the fluid in the second fluid passage 151 can flow into the first fluid passage 141 through the communication hole 1512, which is advantageous in that stacking of the second plate 15 and the first plate 14 is achieved, and the space occupied by the base 10 is reduced. Further, by defining the first end of the communication hole 1512 to have a smaller radial dimension than the second end of the communication hole 1512, for example, the second plate 15 is positioned above the first plate 14, the communication hole 1512 is a tapered hole having a small upper end volume and a large lower end volume, the upper end of the communication hole 1512 communicates with the second groove 1511, and the lower end of the communication hole 1512 communicates with the first fluid passage 141. When the fluid flows back, the sectional area of the upper end of the communication hole 1512 is reduced, so that the resistance to the fluid flowing back from the first fluid passage 141 to the second fluid passage 151 can be increased, and the fluid can be reduced from entering the pump chamber communicating with the upper end of the communication hole 1512.

Alternatively, the second plate body 15 and the first plate body 14 may be stacked in the thickness direction, the fluid inlet 11 and the fluid outlet 12 may be located on the same side of the base body 10, and the communication hole 1512 may be located on the other side of the base body, facilitating arrangement of the flow blocking member 20. For example, the second plate 15 is located above the first plate 14, the fluid inlet 11 is located near the right side of the second plate 15 in the cross section along the up-down direction, the fluid outlet 12 is located near the right side of the first plate 14, the communication hole 1512 is located near the left side of the second plate 15 and extends in the top-down direction, the second groove 1511 on the second plate 15 extends in the left-right direction, and the first fluid channel 141 on the first plate 14 extends in the left-right direction, so that the length of the flow channel 13 can be extended.

According to one embodiment of the present invention, as shown in fig. 1, 4 and 5, the number of spoilers 20 is plural, and the number of spoilers 20 between two diaphragms 30 is smaller than the number of spoilers 20 between the diaphragms 30 and the fluid outlet 12. For example, the number of first flow-blocking pieces 22 in the first fluid passage 141 is smaller than the number of second flow-blocking pieces 23 in the second fluid passage 151, which is advantageous in ensuring resistance against backflow of fluid from the first fluid passage 141 to the second fluid passage 151, and also in simultaneously installing two diaphragms 30 in a limited space.

In some embodiments of the present invention, the control element 40 is a piezoelectric patch that is affixed to the side of the diaphragm 30 remote from the substrate 10. That is, the control element 40 may employ a piezoelectric sheet, for example, through which the diaphragm 30 may be driven to vibrate up and down. When a piezoelectric sheet is used, the piezoelectric sheet may be attached to the diaphragm 30.

Optionally, as shown in fig. 1 and 2, the valveless piezoelectric micropump 100 further includes a protective housing 50, where the protective housing 50 may be located on a side of the control element 40 away from the base 10, and the protective housing 50 may function to protect the control element 40 and protect the diaphragm 30.

Optionally, as shown in fig. 1 and 2, the valveless piezoelectric micropump 100 further includes a sealing platen 60, and the sealing platen 60 may be located between the protective shell 50 and the substrate 10. Two circular holes may be formed in the sealing platen 60, and a diaphragm 30 may be attached to the outside of each circular hole. In the mounting, the sealing platen 60 may be fixed to the base 10, for example, to the upper side of the second plate 15, and the lower side of the second plate 15 may be fixed to the first plate 14.

In summary, the valveless piezoelectric micropump 100 according to the embodiment of the present invention employs the combination of the base body 10, at least two flow blocking members 20, two diaphragms 30, and the control element 40, and has the advantage of simple structure, and can realize a large pumping amount.

While certain specific embodiments of the invention have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the invention. It will be appreciated by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.

Claims (11)

1. A valveless piezoelectric micropump comprising:

the base body is provided with a fluid inlet, a flow channel and a fluid outlet, a first end of the flow channel is communicated with the fluid inlet, and a second end of the flow channel is communicated with the fluid outlet;

at least two flow-blocking members spaced apart in a direction of fluid flow from said fluid inlet to said fluid outlet, each of said flow-blocking members being located in said flow path, each of said flow-blocking members being capable of generating a first flow resistance to fluid along the direction from said fluid outlet to said fluid inlet and a second flow resistance to fluid along the direction from said fluid inlet to said fluid outlet, said first flow resistance being greater than said second flow resistance to permit fluid to enter from said fluid inlet and exit from said fluid outlet;

two diaphragms spaced apart in a fluid flow direction from the fluid inlet to the fluid outlet, each diaphragm forming a pump chamber with a portion of the flow passage, one of the two diaphragms being located between the fluid inlet and the flow blocking member adjacent to the fluid inlet, the other of the two diaphragms being located between the two flow blocking members;

and the control element is respectively connected with the two diaphragms, and is used for controlling each diaphragm to move towards or away from the matrix so as to increase or decrease the volume of the corresponding pump cavity.

2. The valveless piezoelectric micropump of claim 1, wherein the flow channel comprises:

the two side walls are distributed at intervals and are arranged oppositely, each side wall is connected with the bottom wall, at least one side wall comprises a first section body, a second section body and a third section body which are sequentially connected along the fluid flow direction from the fluid inlet to the fluid outlet, the flow blocking piece is arranged on the bottom wall, the curvature of a part, corresponding to the third section body, of the side wall surface of the flow blocking piece is larger than that of the third section body, and the distance between the side wall surface of the flow blocking piece and the second section body is larger than that between the side wall surface of the flow blocking piece and the third section body.

3. The valveless piezoelectric micropump of claim 2, wherein a spacing between the sidewall surface of the flow blocking member and the first segment is less than a spacing between the sidewall surface of the flow blocking member and the second segment.

4. The valveless piezoelectric micropump according to claim 2, wherein the portion of the side wall surface of the flow blocking member corresponding to the fluid outlet is provided with an inwardly recessed groove along a fluid flow direction from the fluid inlet to the fluid outlet.

5. The valveless piezoelectric micropump according to any one of claims 1 to 4, wherein said flow path includes a first fluid passage and a second fluid passage in communication with each other, one of said flow resistors being disposed in each of said first fluid passage and said second fluid passage, said substrate including:

the first plate body and the second plate body are mutually stacked, the first plate body is provided with the fluid outlet and the first fluid channel, and the second plate body is provided with the fluid inlet and the second fluid channel and simultaneously corresponds to the two vibrating membranes.

6. The valveless piezoelectric micropump of claim 5, wherein said first fluid channel comprises:

the first groove is formed in one side, close to the second plate body, of the first plate body, and the flow blocking piece is arranged in the first groove.

7. The valveless piezoelectric micropump of claim 5, wherein said second fluid channel comprises:

the second groove is formed in one side, far away from the first plate body, of the second plate body, the flow blocking piece is arranged in the second groove, and the second groove corresponds to the two vibrating membranes at the same time.

8. The valveless piezoelectric micropump of claim 7, wherein said second recess comprises:

a first opening and a second opening which are spaced apart in a fluid flow direction from the fluid inlet to the fluid outlet, the first opening corresponding to one of the diaphragms, the second opening corresponding to the other diaphragm;

a first slot, a first end of the first slot in communication with the first opening;

the first end of the second groove is communicated with the second end of the first groove, and the flow blocking piece is arranged in the second groove;

a third slot, a first end of the third slot in communication with a second end of the second slot, the second end of the third slot in communication with the second opening;

wherein the radial dimension of the first opening is greater than the radial dimension of the first slot and/or the radial dimension of the second opening is greater than the radial dimension of the third slot.

9. The valveless piezoelectric micropump of claim 7, wherein said second fluid channel further comprises:

the communication hole penetrates through the second plate body in the thickness direction, the first end of the communication hole is communicated with the second groove in the stacking direction from the second plate body to the first plate body, the second end of the communication hole is communicated with the first fluid channel, and the radial size of the first end of the communication hole is smaller than that of the second end of the communication hole.

10. The valveless piezoelectric micropump of claim 1, wherein the number of flow resistors is a plurality, the number of flow resistors between two of the diaphragms being less than the number of flow resistors between the diaphragms and the fluid outlet.

11. The valveless piezoelectric micropump according to claim 1, wherein the control member is a piezoelectric patch attached to a side of the diaphragm remote from the substrate.