JPH01167475A - Pump employing piezoelectric element - Google Patents

Abstract

PURPOSE:To reduce pulsation by forming a plurality of flow paths in multi- layers in a structure laminated with this boards and arranging piezoelectric elements in multi-layers in the flow path while facing each other thereby increasing counter-flow resistance and delivery pressure. CONSTITUTION:At least three sheets of piezoelectric elements 1a, 1b, 1c are assembled into an uppermost thin board 2a while a through-hole 3a is made at a section of next thin board 2b corresponding to the piezoelectric element and joint section thereof, and piezoelectric elements 1d, 1e, 1f are arranged on a third thin board 2c such that they face with the piezoelectric elements on the first thin board 2a. Furthermore, notches 4, 5 corresponding to delivery and suction ports are provided. A fourth thin board 2d is constructed similarly with the second thin board 2b and a fifth thin board 2e is constructed similarly with the first thin board 2a. When they are laminated, two flow paths are formed and opened/closed through three sets of piezoelectric elements.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a micro-volume liquid delivery pump, and more particularly to a piezoelectric element applied pump suitable for a small, multi-channel micro-liquid delivery pump.

[Conventional technology]

Conventionally, as described in JP-A-52-106103, two concentric cylinders are provided, at least one of the concentric cylinders is divided into radially polarized piezoelectric elements, and these piezoelectric elements are sequentially polarized. It was deformed in the radial direction to force liquid between the concentric cylinders.

[Problem that the invention seeks to solve]

In the above conventional technology, the pressure applied to the liquid when the piezoelectric element is deformed generates flows in both the upstream and downstream directions. No consideration has been given to reducing the resistance, requiring a pressure source upstream, or when the supply destination is a higher pressure area, or reducing the size of multiple channels. Problems such as the inability to transport liquid due to resistance due to the surface tension of the liquid (because the tubes and channels are thin for transporting minute amounts of liquid) and the problem of not being able to deal with this problem especially with regard to multi-channel design and miniaturization in narrow spaces. there were.

The object of the present invention is to form a plurality of channels in a multilayered manner in a structure in which thin plates of approximately 0.2+n++ are laminated, and to arrange piezoelectric elements facing each other in a multilayered manner through the channels. , by arranging piezoelectric elements in parallel, the backflow resistance is increased,
Increase discharge pressure, reduce pulsation, and increase the number of channels.
The object of the present invention is to provide a piezoelectric element applied pump that enables miniaturization.

[Means for solving problems]

The above purpose is to form a flow path in a multilayer structure of thin plates,
By providing three or more piezoelectric elements at opposing positions across the plurality of flow channels and making their movements C1 different from each other, a basic structure is provided that simultaneously generates a flow in the plurality of flow channels. By arranging three or more basic structures in parallel and using this movement to strongly prevent backflow and increase discharge pressure, a multi-channel, small-sized micro-liquid pump is achieved.

[Effect]

The case will be explained in the case of five thin plates made up of at least five thin plates. At least three piezoelectric bare hands are built into the topmost thin plate, through-holes are built into the next thin plate in the part corresponding to the piezoelectric element and the connecting part, and the third thin plate is fitted with the first piezoelectric element. The piezoelectric element is arranged so as to face the piezoelectric element of the thin plate, and notches corresponding to the discharge port and the suction port are provided.

The fourth thin plate has the same configuration as the second thin plate, and the third thin plate has the same configuration as the first thin plate.

By stacking these, two channels are formed, and these two channels are opened and closed by a set of three piezoelectric elements.

This combination of three piezoelectric elements opens and closes the flow path at high speed, prevents backflow, and merges two flow paths into one to prevent pulsation, making it a compact piezoelectric pump element for multi-channel use. can perform the following actions.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. Its structure consists of five thin plates 2a, 2b, and 2c.

Piezoelectric elements 1a, lb, and lc are incorporated into the 0g plate 2a, which is made up of 2d and 2e, and these are laminated. thin plate 2
A channel through hole 3a is formed in b as shown in the figure.

The thin plate 2c is basically the same as the thin plate 2a, and the piezoelectric element 1
d, e, and f are incorporated, and notches (suction part 4, discharge part 5) are formed. The thin plate 2d is the same as the thin plate 2b, and the thin plate 2e is also the same as the thin plate 2a. The liquid flows from the suction port 4 through two routes: one through the through hole 3a formed by the thin plates 2a, 2b, and 2c, and the other through the through hole 3b formed through the thin plates 2c, 2d, and 2e.

FIG. 2 is a cross-sectional view of a pump using a piezoelectric element when a VC layer is formed.
, 1b, 10.1c and 1f, through the through hole 3b, 1d
and 1g, 1e and 1h, 1f and 11 are facing each other, and l
a-1d-1g, 1b-1'e-1h, and 1c-1f
Each set of -1i operates simultaneously. Within each set, piezoelectric elements 1a and 1g are deflected in the same direction, and the pressure f
f1la moves in the opposite direction, and the through hole 3a
If the side is open, the through hole 3b side is closed, and the through hole 3a side is closed.
If the side is closed, the through hole 3b side is opened, and the intermittent flows in the two channels are combined to form a continuous flow. FIG. 3 shows the operation sequence of this device, in which (a) shows the starting state, and (b)
) is the piezoelectric element 1a.

ld and Ig are reversed, the volume between the piezoelectric elements 1a and 1d increases, and liquid flows into it from the suction port 4.

At the same time, the volume between the piezoelectric elements 1d and 1g decreases, and the liquid therein is pushed out and flows out from the discharge port 5. At this time, since the space surrounded by the piezoelectric elements 1b and 18 and 1c and 1f is narrow, it becomes a strong resistor and prevents backflow. Also, part of the liquid between the piezoelectric elements 1d and 1g flows backward, but it is absorbed into the space between the piezoelectric elements 1a and 1b, so that the liquid is finally transferred to the piezoelectric Elements 1b, 18 and 1h
is reversed, the space between the piezoelectric elements 1b and 10 increases, and at the same time, the space between the piezoelectric elements 1e and 1h decreases, and at the same time, the space between the piezoelectric elements 1b and 10 increases, and the liquid from the suction port 4 is further guided. Push out. In the next step (d), piezoelectric elements 1a, 1d, and 1g, piezoelectric elements 1c, and 1f and 11 are reversed, and the volume of the space between piezoelectric elements 1a and 1d and the space between piezoelectric elements 1f and 11 is reduced. , the former pushes out the liquid in the through hole 3a to the discharge part 5,
The latter pushes out the liquid in the through hole 3b to the discharge part 5. At the same time, the volume of the space between the piezoelectric elements 1c and 1f and the space between the piezoelectric elements 1d and 1g increases, and the former pushes out the liquid in the through hole 3b. The liquid in 3a is sucked out toward the discharge port 5, and the latter sucks the liquid in the suction port 4 into the flow path 3b.

In the next step (e), the piezoelectric elements 1b, 1e, and 1h are reversed, the space between the piezoelectric elements 1b and le is reduced, and the flow path 3a
The liquid is further pushed out to the discharge port 5.

At the same time, the space between the piezoelectric elements 1e and 1h increases and the liquid in the through hole 3b is further sucked out from the suction part 4 toward the discharge part 5. and 1f and 11 are reversed, ° piezoelectric elements 1a and 1d
The volume of the space between the piezoelectric elements 1f and 11 increases, and the volume of the space between the piezoelectric elements 1f and 11 increases.

The liquid is sucked into the through hole 3a from the suction part 4, and the latter further sucks the liquid in the through hole 3b toward the discharge port.

At the same time, the volumes of the space between the piezoelectric elements 1c and 1f and the space between the piezoelectric elements 1d and 1g decrease, and the former pushes out the liquid in the through hole 3a to the discharge part 5, and the latter pushes out the liquid in the through hole 3.
The next step of pushing out the liquid b towards the discharge part 5 is (
Return to step c), repeat this sequence one by one, and send out a small amount of liquid.

According to this embodiment, by making the suction part and the discharge part common to the two channels, it is possible to reduce the frequency of the piezoelectric element by half when considering the flow rate as a reference.

According to this embodiment, the piezoelectric elements are arranged to face each other through the flow path and are in contact with each other, so that, except for the outer piezoelectric element, the piezoelectric elements are shared by the flow path sandwiching the piezoelectric element. Since the operation also takes advantage of the sharing, there is no waste in operation, and the piezoelectric element driving device can be well controlled if there are as many channels as there are piezoelectric element pairs arranged along the flow path. Since it is not complicated and has a structure in which narrow thin plates are layered, it is possible to simultaneously achieve miniaturization and multi-channel design.

〔Effect of the invention〕

According to the present invention, the backflow resistance is increased, the discharge pressure is increased,
It is possible to reduce pulsation, and enable multi-channel and miniaturization.

[Brief explanation of the drawing]

FIG. 1 is a layered cross-sectional view of an embodiment of the present invention, FIG. 2 is a cross-sectional principle diagram of an embodiment of the present invention, and FIG. 3 is a sequence explanatory diagram of an embodiment of the present invention. 1... Piezoelectric element, 2... Thin plate, 3... Through hole, 4
...Notch. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1. In a flow path formed by a first thin plate forming a through hole and a second thin plate incorporating a piezoelectric element, three or more piezoelectric elements sandwich the flow path. A piezoelectric element applied pump characterized in that the piezoelectric elements are adjacent to each other. 2. A pump using a piezoelectric element according to claim 1, wherein the piezoelectric elements adjacent to each other across the flow path are deflected in opposite directions. 3. The piezoelectric element pump according to claim 1, wherein a check valve or a resistor for preventing backflow is provided at the fluid inlet and outlet of the flow path. 4. In a flow path formed by a first thin plate forming a through hole and a second thin plate incorporating a piezoelectric element, three or more enlarged portions of the flow path are provided, and each enlarged portion is A pump using a piezoelectric element, in which the piezoelectric element is applied to each of the piezoelectric elements, and each of the piezoelectric elements can be driven independently.