JPH03107585A - Piezoelectric pump - Google Patents

Abstract

PURPOSE:To fill or drop a very small amount of fluid continuously and accurately at high speed by arranging a pair of piezoelectric elements in a face-to-face relation on each outer side surface of a pair of counter-arranged elastic members arranged in a face-to-face relation, from a fluid inlet pipe to a fluid discharge pipe. CONSTITUTION:On each outer side surface of a pair of first elastic plates 1, 2 from a fluid inlet pipe 5 to a fluid discharge pipe 6, piezoelectric devices 3, 4 are arranged in a face-to-face relation in a zigzag way, and so as for a part thereof to be overlapped, and second elastic plates 7, 8 are arranged on the surface thereof, whereby piezoelectric elastic bodies 9, 10 are formed. A circumference of each piezoelectric elastic body 9, 10 is sealed air-tight with a frame body 11. To each piezoelectric device 3, 4, each voltage cable group is connected, respectively. By applying voltage to each piezoelectric device 3, 4 in turn, so as to alternately deform it, each piezoelectric elastic body 9, 10 is stretched and contracted, whereby fluid is taken in and discharged.

Description

[Detailed Description of the Invention] [Summary] This invention relates to a piezoelectric pump that uses a piezoelectric element as a driving source to continuously inject and drop a relatively small amount of fluid (gas, liquid, etc.) accurately and at high speed. By devising one part, the amount of injection or dripping of a minute amount of fluid can be easily and variably controlled without limiting the fluid storage capacity, and moreover, the minute amount of fluid can be dripped continuously, accurately, and at high speed. - A pair of elastic members are disposed facing each other, the periphery thereof is hermetically sealed, and a fluid suction pipe is provided on one side and a fluid discharge pipe is provided on the other side, A plurality of piezoelectric elements are arranged on the outer surface of each elastic member so as to face each other in a zigzag pattern from the fluid suction pipe side to the fluid discharge pipe side, and some of the piezoelectric elements are arranged in a zigzag manner to face each other in an Oharab relationship. By supplying a signal to the piezoelectric element that causes it to alternately expand and contract from the fluid suction pipe side to the fluid discharge pipe side,
By alternately bending a portion of the pair of elastic members between the opposing piezoelectric elements in the directions of separating and approaching each other, the fluid sucked from the fluid suction pipe is sequentially transferred to the fluid discharge pipe side. The fluid is configured to be discharged from a fluid discharge pipe.

[Industrial application field]

The present invention relates to a piezoelectric pump that uses a piezoelectric element as a driving source to continuously inject and drop a relatively small amount of fluid (gas, liquid, etc.) accurately and at high speed.

In fields such as medicine, chemical industry, or chemical analysis,
Various devices for injecting or dropping relatively small amounts of fluid such as gas or chemicals are widely used, and the amount of injection or dropping of the small amount of fluid can be easily variably controlled.
There is a need for a WFZ configuration that can continuously and accurately inject and drop small amounts of fluid at high speed.

[Prior Art] Conventionally, a micro cylinder or the like has been used for injecting or dropping a small amount of chemical substances or fluids such as chemicals.

[Problem to be solved by the invention]

By the way, in the micro cylinder as mentioned above,
The capacity of a cylinder that accommodates fluid is naturally limited, and if it is necessary to inject or drop an amount of fluid that exceeds the capacity of the cylinder, resupply the emptied microcylinder with fluid and continue. Fluid must be injected or dispensed, and such fluid delivery operations may result in incorrect injected or dispensed amounts each time the fluid inject or dispense operation is interrupted. There were also problems such as chemical reactions changing abnormally, leading to a decrease in reliability.

In view of the above-mentioned conventional situation, the present invention devises the fluid extrusion drive unit so that the amount of injection or dripping of a small amount of fluid can be easily and variably controlled without limiting the fluid storage capacity.
Moreover, it is an object of the present invention to provide a novel piezoelectric pump capable of continuously injecting and dropping small amounts of fluid accurately and at high speed.

[Means to solve the problem]

In order to achieve the above-mentioned object, the present invention arranges a pair of elastic members facing each other, airtightly seals the periphery thereof, and has a fluid suction pipe on one side and a fluid discharge pipe on the other side, and each A plurality of piezoelectric elements are arranged on the outer surface of the elastic member in a zigzag pattern facing each other from the fluid suction pipe side to the fluid discharge pipe side, and some of the piezoelectric elements face each other in an Ohara-tube relationship. A signal that alternately expands and contracts sequentially from the fluid suction pipe side to the fluid discharge pipe side is supplied to the piezoelectric element to separate and approach a portion of the pair of elastic members between the opposing piezoelectric elements. By alternately bending in the directions, the fluid sucked in from the fluid suction pipe is sequentially transferred to the fluid discharge pipe side and discharged from the fluid discharge pipe.

[For production]

In the configuration of the present invention, a plurality of piezoelectric elements are arranged in a zigzag manner to face each other on the outer surfaces of a pair of opposing elastic members, and a plurality of piezoelectric elements are arranged in a zigzag-like manner so that a portion of the piezoelectric elements overlap with each other, and a plurality of piezoelectric elements are provided with fluid from the fluid suction pipe side. By supplying a voltage signal that generates a strain that alternately repeats expansion and contraction toward the discharge pipe side, parts of the pair of elastic members between the opposing piezoelectric elements are moved apart and brought closer together. Alternately bend in the direction you want.

Each time this bending phenomenon is moved from the fluid suction pipe side to the fluid discharge pipe side, the small amount of fluid sucked from the fluid suction pipe into the spaced part caused by the bending is sequentially transferred to the fluid discharge pipe side, and the fluid is discharged. It can be drained from the pipe.

The speed and amount of deflection at which the corresponding surfaces of the elastic members between the opposing piezoelectric elements are deflected in the directions n in which they move away from and approach each other are determined by the frequency of the voltage signal applied to each of the corresponding piezoelectric elements;
Alternatively, it can be realized by controlling the method of applying a voltage signal to the piezoelectric element using an external control circuit or the like.

In addition, responses such as voltage application to the corresponding piezoelectric element and expansion and contraction of each piezoelectric element, and deflection of the pair of elastic members, are extremely fast, and the fluid sucked from the fluid suction pipe is transferred to the fluid discharge pipe at high speed. Since it can be transported, it becomes possible to inject or drop a small amount of fluid at high speed.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a perspective view showing the structure of an embodiment of a piezoelectric pump according to the present invention, and FIG. 2 is a sectional view taken along the line A--A shown in FIG.

In both of these figures, 1 and 2 are a pair of elastic plates made of hard rubber, etc., and the outer surfaces of the pair of first elastic plates 1 and 2 are arranged so that the side is closer to the fluid discharge vibro than the fluid suction pipe 5 side. A plurality of piezoelectric elements 3 and 4 are arranged in two layers facing each other in a zigzag pattern, with some overlapping, and a second elastic plate 7.8 is bonded to the surface of each piezoelectric element 3, 4. It constitutes a piezoelectric elastic body 9.10.

The pair of piezoelectric elastic bodies 9.10 are arranged facing each other as shown in the figure, and the periphery thereof is hermetically sealed by the frame 11, and the pair of piezoelectric elastic bodies 9.10 are pressed against each other in a U-shape. A preload is applied as shown.

Further, the pair of piezoelectric elastic bodies 9 and 1 facing each other have a fluid suction pipe 5 on one side and a fluid discharge vibro on the other side.
It is arranged so that it communicates with 0.

] 2.13 is a group of voltage cables for applying voltage to each of the plurality of piezoelectric elements 3 and 4 embedded in the pair of piezoelectric elastic bodies 9.10.

In such a structure, a voltage is sequentially applied to each of the plurality of piezoelectric elements 34 embedded in the pair of piezoelectric elastic bodies 9 and 10 described in ii from the fluid suction pipe 5 side, and the corresponding piezoelectric elements 3.4 are By sequentially repeating the distortion due to expansion and contraction, the corresponding surfaces of the pair of piezoelectric elastic bodies 9 0 facing each other as shown in FIG. The minute amount of fluid sucked into the spaced part al formed by the deflection that concaves inward and the deflection that partially expands outward from the fluid suction pipe 5 is generated as shown in FIG. As shown in the separation part d
As 1 is moved as l)2+ al..., it is sequentially transferred to the fluid ejection vibro side and can be ejected from the fluid ejection vibro.

Note that the plurality of piezoelectric elements embedded in the pair of piezoelectric elastic bodies 9 and 10 are not necessarily limited to a two-layer structure.
Although a layered structure may be used, as shown in this example, a two-layer structure can be obtained by arranging a plurality of piezoelectric elements arranged in a single layer at positions where the strain phase of the piezoelectric elements is shifted from each other in a layered manner. By doing so, the separation portion can be moved continuously and smoothly.

Further, the unit discharge amount of the small amount of fluid discharged from the fluid discharge vibro can be controlled with high precision by adjusting the size of the piezoelectric elements arranged in layers, the voltage application method, etc.

Furthermore, the response such as the deflection of the pair of elastic members due to the expansion and contraction of each piezoelectric element corresponding to the application of voltage is extremely fast, and the other end of the fluid discharge vibro is filled with a large fluid such as gas or liquid. By connecting it to a supply tank and supplying the fluid to the piezoelectric pump to drive it, the fluid sucked from the fluid suction pipe 5 can be continuously transferred at high speed to the fluid discharge pipe side, so that a trace amount of fluid can be transferred to the fluid discharge pipe side. It becomes easy to inject or drop a unit of fluid into a required area at high speed.

Furthermore, this piezoelectric pump can be easily miniaturized, and by having a structure in which the fluid injection tip or the fluid droplet tip is directly connected, the volume between them is minimized, reducing waste of internal fluid. be able to.

〔Effect of the invention〕

As is clear from the above description, according to the piezoelectric pump according to the present invention, it is possible to easily and variably control the discharge amount of a minute amount of fluid, and it is possible to continuously inject and drop a minute amount of fluid at high speed. It has an excellent advantage of being able to transport fluids, and can be applied to small devices that continuously and rapidly inject or drop small amounts of fluids consisting of gases or liquids such as pharmaceuticals in fields such as the chemical industry and medical research. It has a remarkable effect in practice.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the configuration of an embodiment of a piezoelectric pump according to the present invention, FIG. 2 is a sectional view taken along the cutting line A-A shown in FIG. 1, and FIG. 1 is a conceptual diagram for explaining an example of the operation of a piezoelectric pump according to the present invention. In FIGS. 1 to 3 (al, (bl), 1.2 is a first elastic plate, 3 and 4 are Piezoelectric element, 5 is a fluid suction vibrator, 6
is a fluid discharge pipe, 7 and 8 are second elastic plates, 9.10 is a piezoelectric elastic body, 11 is a frame body, 12.13 is a voltage cable, a
l+a2+a3 respectively indicate the separation parts. 1

Claims (1)

[Claims] A pair of elastic members (1, 2) are arranged facing each other, the periphery thereof is hermetically sealed, and a fluid suction pipe (5) is provided on one side.
, a fluid discharge pipe (6) is provided on the other side, and a plurality of grooves are provided on the outer surface of each of the elastic members (1, 2) from the fluid suction pipe (5) side to the fluid discharge pipe (6) side. Piezoelectric elements (3, 4) are arranged to face each other in a zigzag pattern, and a fluid discharge pipe (6) is connected to each piezoelectric element (3) facing each other in a partially overlapping relationship from the fluid suction pipe (5) side. ) side, a portion of the pair of elastic members (1, 2) between the opposing piezoelectric elements is alternately moved away from and toward each other. By bending the fluid suction pipe (5
) A piezoelectric pump characterized in that the fluid sucked from the fluid discharge pipe (6) is sequentially transferred to the fluid discharge pipe (6) and discharged from the fluid discharge pipe (6).