KR100561728B1 - piezoelectric pump - Google Patents

Abstract

The present invention provides a piezoelectric pump capable of pumping a fluid without a check valve by allowing a plurality of piezoelectric actuators to which a piezoelectric element is attached to the conductive elastic plate to sequentially interoperate with each other in a different displacement difference.

A pump case 20 having a suction hole 21 to which the fluid suction pipe 11 is connected and a discharge hole 22 to which the fluid discharge pipe 12 is connected, and a piezoelectric element attached to the conductive elastic plate 31. In a piezoelectric pump including a controller 40 for controlling a piezoelectric actuator 30 for causing displacement and pumping fluid to an outlet side, a plurality of channels sharing the flow passage 24 inside the pump case 20. The fluid pumping chamber 23 is installed, and each of the fluid pumping chambers 23 is provided with piezoelectric actuators 30 which share the adjacent flow paths 24 with each other, so that the controller 40 controls the respective piezoelectric actuators 30. The piezoelectric actuator 30 controlled by the controller 40 is configured to operate in conjunction with each other by sequentially controlling different displacement differences, and the 0 °, 90 °, 180 °, and 270 ° displacement widths (phase difference) are controlled. Characterized in that it is set to have.

Piezoelectric pumps, check valves, conductive elastic plates, piezoelectric elements

Description

Piezoelectric pump

1 is an exemplary diagram of a piezoelectric pump using a conventional unimorph piezoelectric actuator;

Figure 2 is an illustration of a piezoelectric pump using a conventional bimorph piezoelectric actuator,

3 is a diagram illustrating an operation relationship of a conventional piezoelectric pump;

Figure 4 is an illustration of a disk-type piezoelectric actuator to which the present invention is applied,

5 is an exemplary view of a piezoelectric pump to which the present invention is applied;

Figure 6 is a reference diagram representing the flow of other fluid in the operation of the piezoelectric pump according to the present invention,

Figure 7 is an illustration of a piezoelectric pump case according to another configuration of the present invention,

Figure 8 is an illustration of a piezoelectric pump according to another embodiment of the present invention,

9 is a cross-sectional view of the piezoelectric pump shown in FIG. 8;

<Explanation of symbols for the main parts of the drawings>

11: fluid suction pipe 12: fluid discharge pipe

20: pump case 21: suction hole

22: discharge hole 23: fluid pumping chamber

24: Euro 30: Piezo actuator

31 conductive conductive plate 34 piezoelectric element

40: controller

The present invention relates to a piezoelectric pump for pumping a small amount of fluid, and more particularly, a plurality of piezoelectric actuators (unimorph or bimorph) to which a piezoelectric element is attached to a conductive elastic plate (unimorph or bimorph) form a different displacement difference and sequentially interlock. The present invention provides a piezoelectric pump that is simple in structure and can reduce failure and noise by pumping fluid without a check valve.

The diaphragm pump is mainly used as a small pump for micro fluid transfer, and the diaphragm displaces the diaphragm by converting the rotational movement of the small motor and the small motor into a reciprocating motion of the rod, thereby providing a relatively small amount through the check valve. Is configured to pump fluid.

Conventionally, as shown in FIG. 1, a fluid suction hole 21 and a discharge hole 22 are provided in a pump case 20, and applied to an inner side of a conductive elastic plate 31, that is, a shim. Controller connected to the lead wires (35a, 35b) of the unimorph piezoelectric actuator 30 is built into a unimorph piezoelectric actuator (30) of the method that is attached to the piezoelectric element 34 to cause a displacement in accordance with the voltage When an electromotive force is applied through the electric field signal of the piezoelectric element 34, the piezoelectric element 34 is displaced in one direction and pumps to the outlet side after introducing the fluid.

As another example, as shown in FIG. 2, a bimorph piezoelectric actuator 30a having piezoelectric elements 34: 34a and 34b attached to both surfaces of the conductive elastic plate 31 has been proposed. The piezoelectric actuator 30a pumps fluid by applying an electromotive force, causing displacement in both directions to which the piezoelectric elements 34a and 34b are attached, thereby causing a larger displacement than the unimorph piezoelectric actuator described above. It is configured to.

The piezoelectric actuator of the above-described conventional structure only generates displacement in accordance with the electric field signal, and thus requires separate check valves 10a and 10b for controlling the suction and discharge of the pumping fluid.

However, the check valves 10a and 10b form a ball to control the flow path inside the sheet and a seat on which the ball rests, so that leakage occurs when the check valve 10 does not operate properly. This has the disadvantage of lowering the pumping performance.

In addition, the check valves 10a and 10b not only generate noise during pumping due to the use of balls for intermittent flow, but also have a problem in that the number of parts increases and the configuration is complicated.

The present invention has been made in view of the problems of the prior art as described above, the present invention is a piezoelectric pump that does not require an improved check valve to perform the pumping action only a plurality of piezoelectric actuators without using a check valve. The purpose of the present invention is to prevent deterioration of pumping performance and noise caused by using a check valve.

In addition, the present invention is another object of the piezoelectric pump structure to be simple yet compact so that it can be used in a variety of medical equipment or home appliances, such as suitable for small amount of fluid transfer.

In order to achieve the above object, the present invention provides a pump case in which a suction hole connected to a fluid suction pipe and a discharge hole connected to a fluid discharge tube are formed in an inner fluid pumping chamber in which a piezoelectric actuator is accommodated, and a piezoelectric element attached to a conductive elastic plate. A piezoelectric actuator including a piezoelectric actuator configured to cause displacement and pump the fluid introduced into a suction hole of a pump case to an outlet discharge hole, and a controller for controlling the piezoelectric actuator, the plurality of which share a flow path inside the pump case. A fluid pumping chamber is installed, and each of the fluid pumping chambers is provided with piezoelectric actuators which share adjacent flow paths so that the controller sequentially controls the respective piezoelectric actuators so that they operate in conjunction with each other with different displacements. The controller is adjacent to one piezo actuator Provides a piezoelectric pump, characterized in that another of the piezoelectric actuator so as to set a different displacement (0 °, 90 °, 180 °, 270 ° displacement) width (a phase difference).

In addition, the present invention is the pump case in which the suction hole and the discharge hole is formed in the inner fluid pumping chamber in which the piezoelectric actuator is accommodated, and the piezoelectric element attached to the conductive elastic plate causes displacement, and the fluid introduced into the suction hole of the pump case is discharged to the outlet side. In a piezoelectric pump including a piezoelectric actuator to be pumped, and a controller for controlling the piezoelectric actuator, the pump case has a plurality of pump cases stacked on the upper and lower sides thereof, and the piezoelectric actuator is assembled to each pump case. The suction hole and the discharge hole are connected to the discharge hole and the suction hole of the pump case stacked on the upper side, and the upper pump case has a fluid suction pipe directly connected to the suction hole of the pump case located at the lower side and the discharge hole of the upper pump case. The fluid discharge pipe to be connected together is installed together, the pump case On one side the guide groove is formed to provide a piezoelectric pump, characterized in that is configured to secure and remove the pump casing which is assembled by a guide block with the guide groove, the up and down laminating.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 4 shows an exemplary view of a disk-type piezoelectric actuator according to the present invention, the piezoelectric actuator 30 is a piezoelectric element 34 is attached to one side of the conductive elastic plate 31, the conductive elastic plate 31 And the piezoelectric element 34 is provided with lead wires 35: 35a and 35b to be soldered and connected to each other. When the controller 40 generates an electric field signal by applying electromotive force to the piezoelectric actuator 30 through the lead wire 35, the piezoelectric element ( 34 has a disk shape for causing displacement in one direction and pumping the fluid introduced into the suction hole 21 of the pump case 20 to the discharge hole 22 at the outlet side.

In addition, the pump case 20 accommodating the piezoelectric actuator 30 has a fluid suction hole 21 to which the fluid suction pipe 11 is connected, and a discharge hole 22 to which the fluid discharge tube 12 is connected, and an inner side thereof. It is provided with a fluid pumping chamber 23 in which the piezoelectric actuator 30 is accommodated.

The piezoelectric actuator 30 mounted in the fluid pumping chamber 23 of the pump case 20 to pump the fluid is connected to the controller 40 controlling the piezoelectric actuator 30 according to the electric field signal of the controller 40. ) Causes the displacement to pump the fluid to the outlet side.

The pump case 20 has a suction hole 21 in which the fluid suction pipe 11 is connected to the inner fluid pumping chamber 23 in which the piezoelectric actuator 30 is accommodated, and a discharge hole 22 in which the fluid discharge pipe 12 is connected. A plurality of fluid pumping chambers 23: 231, 232, 233, 234, and 235, which share a flow path 24, are formed inside the pump case 20, respectively. A plurality of piezoelectric actuators 30: 301, 302, 303, 304, and 305 that share adjacent flow paths 24 are mounted in the housing.

These are connected to the controller 40, respectively, so that the controller 40 sequentially controls the respective piezoelectric actuators 30 so that they can operate in conjunction with each other in a different displacement difference.

Each piezoelectric actuator 30 controlled by the controller 40 is set in order to have a 0 °, 90 °, 180 °, and 270 ° displacement width (phase difference) so that they can operate sequentially in conjunction with each other.

Meanwhile, in the present invention, in one embodiment, a plurality of piezoelectric actuators 30 are arranged side by side in one pump case 20 through a fluid discharge port facing the fluid flowing through one fluid suction inlet. Although the piezoelectric pump having a discharged configuration is illustrated and described, another embodiment may form the piezoelectric pump in a compact and compact structure as shown in FIGS. 7 to 9.

Figure 7 is an exemplary view of a piezoelectric pump case according to another configuration of the present invention, Figure 8 is an illustration of a piezoelectric pump having a structure in which a plurality of pump cases are stacked up and down, Figure 9 is a cross-sectional view of the piezoelectric pump,

As shown therein, the pump case 20 having the suction hole 21 and the discharge hole 22 is formed in the inner fluid pumping chamber 23 in which the piezoelectric actuator 30 is accommodated, and attached to the conductive elastic plate 31. The piezoelectric element 34 which causes the displacement and pumps the fluid introduced into the suction hole 21 of the pump case 20 to the outlet side discharge hole 22, and the piezoelectric actuator 30 In the piezoelectric pump including a controller 40 for controlling the pump case, a plurality of pump cases 201, 202, 203, 204 are stacked on the upper and lower sides thereof, and the piezoelectric actuator 30 is assembled to each pump case 20. Suction hole 21 and discharge hole 22 are connected to discharge hole 22 and suction hole 21 of pump case 202 stacked on the upper side, and the uppermost pump case 204 Fluid suction pipe 11 directly connected to the suction hole 21 of the pump case 201 located on the lower side The discharge hole 22 the fluid discharge pipe 12 is connected to the top side of the pump case 204 is juxtaposed with.

In addition, the guide groove 26 is formed on one side of the pump case 20 to fix and separate the pump case 20 stacked up and down by the guide block 27 assembled into the guide groove 26. And a lead wire drawing passage 271 formed on the inner surface of the guide block 27 to form a recess in the inner surface of the guide block 27 so as to lead the lead wire 35 soldered to each piezoelectric actuator 30 to the outside. And a lead wire 35 drawn out through the guide block 27 to the controller 40.

Thus, when the piezoelectric pump having a configuration stacked up and down is assembled such that the discharge hole of each piezoelectric actuator is connected to the inlet port of another pump case adjacent to the pump, the fluid pumped through the first pump case 201 is the second pump case. 202 may be introduced, and the fluid introduced into the second pump case 202 may be sequentially pumped through the third and fourth pump cases 203 and 204.

In order to discharge the inflow of the fluid and the pumped fluid to the desired area, the pump case 204 located at the top thereof includes a fluid supply pipe 11 for supplying the fluid to the piezoelectric pump and a fluid discharge pipe for transporting the pumped fluid through the discharge port. 12 is installed together, the fluid supply pipe 11 is directly connected to the fluid suction hole of the pump case 201 located at the bottom.

In the present invention configured as described above, a plurality of unimorphic piezoelectric actuators are disposed inside the pump case, and each piezoelectric actuator discharges the fluid introduced into the suction hole 21 of the pump case 20 to the outlet side discharge hole 22. By applying electric fields such that they operate in conjunction with each other to pump, it is possible to sequentially pump a plurality of piezoelectric actuators so that the fluid introduced to the suction side proceeds to the outlet side without a check valve.

When an electromotive force is applied to the piezoelectric actuator, the first piezoelectric actuator causes a displacement from the suction side of the piezoelectric actuator connected to the suction port formed in the pump case when the displacement is induced in one direction, and the second piezoelectric actuator is subjected to a 90 ° phase delay. The displacement starts, and the third piezoelectric actuator starts the displacement with a 180 ° delay, and the pumping operation is repeated in which the fluid is introduced into the space generated by the displacement of each actuator and discharged to the outlet side.

As described above, the present invention uses a plurality of piezoelectric actuators attached to the pump case by applying an electric field so that they operate in conjunction with each other, it is possible to pump the fluid introduced to the suction side to the outlet side without a check valve, so that the number of parts It is a very useful invention having the advantage of being able to realize low noise because it is small and its structure is simple and does not frequently cause trouble or repair, and there is no noise caused by the check valve.

Claims (4)

delete A discharge hole in which the fluid suction pipe 11 is connected to the suction hole 21 and the fluid discharge pipe 12 are connected to the plurality of fluid pumping chambers 23 sharing the flow passage 24 inside the piezoelectric actuator 30 is accommodated. The pump case 20 in which the ball 22 is formed and the piezoelectric element 34 attached to the conductive elastic plate 31 cause displacement, and the fluid flowing into the suction hole 21 of the pump case 20 is discharged. The piezoelectric actuator 30 and the piezoelectric actuator 30 which share the flow path 24 adjacent to each other are pumped to the discharge hole 22, and each adjacent fluid pumping chamber 23 is mounted, and they interlock | operate by making different displacements. In the piezoelectric pump comprising a controller 40 which is configured to operate and to control each piezoelectric actuator 30 in sequence, Each piezoelectric actuator 30 controlled by the controller 40 is configured to operate in a displacement width (phase difference) of 0 °, 90 °, 180 °, 270 °. A pump case 20 in which the suction hole 21 and the discharge hole 22 are formed in the inner fluid pumping chamber 23 in which the piezoelectric actuator 30 is accommodated, and the piezoelectric element 34 attached to the conductive elastic plate 31. ) Causes a displacement and a piezoelectric actuator including a piezoelectric actuator 30 configured to pump the fluid introduced into the suction hole 21 of the pump case 20 to the outlet side discharge hole 22, and a controller 40 controlling the same. In the pump, The pump case 20 has a plurality of pump cases 201, 202, 203, and 204 stacked on top and bottom thereof, and the suction hole 21 and the discharge hole 22 of the piezoelectric actuator 30 assembled to each pump case 20. ) Is connected to the discharge hole 22 and the suction hole 21 of the pump case 202 stacked on the upper side thereof, and the suction hole of the pump case 201 located at the bottom of the pump case 204 at the uppermost side. A fluid suction pipe 11 directly connected to 21 and a fluid discharge pipe 12 connected to a discharge hole 22 of the uppermost pump case 204 are provided together, and each of the fluid discharge pipes 12 connected to the pump case 20 is provided together. The piezoelectric actuator 30 is a piezoelectric pump, characterized in that the controller 40 is configured to control sequentially so that they operate in conjunction with different displacements. According to claim 3, The guide groove 26 is formed on one side of the pump case 20, The guide groove 26 is provided with a guide block 27 having a lead wire drawing passage 271 is provided, Piezoelectric pump, characterized in that configured to fix and separate the pump case 20 to be stacked below.

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