JPS6270677A - Piezoelectric pump - Google Patents

Abstract

PURPOSE:To increase a rate of volume flow of a fluid by arranging two piezoelectric plates in such a way that the space between them where they face each other is made wider as they go starting from the inlet port side toward the outlet port side. CONSTITUTION:A pair of piezoelectric plates 11 is provided on the upper and lower sides of a fluid passage in a pump main body 1, and a tank chamber 10 is formed between both of the piezoelectric plates 11. And each of these piezoelectric plates 11 is arranged in such a way that the space between them where they face each other is made wider gradually as they go from the inlet port (2) side toward the outlet port (3) side. As this configuration allows the component of a force to the direction of the outlet port 3 which is produced when these piezoelectric plates 11 are deflected inward, to act on a fluid so as to enable a discharging flow rate to be increased for increasing the rate of volume flow of a pump.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a piezo pump that sucks in and discharges fluid by utilizing the vibration of a voltage plate that is deflected by the application of voltage.

Problems to be Solved by the Prior Art and the Invention In the piezo pump 1, a pair of piezoelectric plates that are deflected by voltage application are stretched across both open ends of a hole formed in the pump body.
A tank chamber is formed between both piezoelectric plates, and a fluid inlet and outlet are provided on both sides of the center of the tank chamber.
By alternately bending both piezoelectric plates in the direction in which the corresponding surfaces move away from each other and in the direction in which they approach each other, the volume of the tank chamber is alternately increased and decreased, so that the fluid sucked into the tank chamber from the suction port is discharged from the discharge port. However, the conventional one is
Since a pair of piezoelectric plates are stretched parallel to each other,
When the fluid flows inside the tank chamber, a large frictional resistance is generated between it and the piezoelectric plate, and the piezoelectric plate vibrates perpendicularly to the direction of the fluid flow, so the fluid is directed toward the discharge port. It is difficult to obtain a sufficient pressing force and therefore it is difficult to sufficiently increase the discharge flow rate of the fluid, and an improvement has been desired.

The present invention was completed based on such a request, and an object of the present invention is to increase the velocity of the fluid flowing inside the tank chamber and increase the discharge flow rate.

Means for solving the interlayer point In order to achieve the above object, the piezo pump of the present invention has the following features:
At both open ends of the hole drilled through the pump body.

A pair of piezoelectric plates that are deflected by the application of a voltage are stretched to form a tank chamber between the pressure plates, and a fluid inlet and outlet are provided on both sides of the tank chamber, sandwiching the center of the pressure plate. The fluid sucked into the tank chamber from the suction port is discharged from the discharge port by alternately bending the piezoelectric plate in a direction in which the corresponding surfaces move away from each other and in a direction in which the corresponding surfaces approach each other to alternately increase and decrease the volume of the tank chamber. In such a piezo pump, the impulse electric plates are arranged diagonally opposite each other in such a manner that the corresponding spacing gradually increases from the suction port side to the discharge port side.

Functions and Effects The present invention has the above-described configuration, and the pair of piezoelectric plates alternately widens and narrows the distance between the corresponding surfaces by applying a voltage, thereby alternately increasing and decreasing the fluid volume in the tank chamber. By repeating this process, fluid is sucked into the tank chamber from the suction port and discharged from the discharge port, and the corresponding interval between the pair of piezoelectric plates gradually becomes wider from the suction port side to the discharge port side. Therefore, the frictional resistance that occurs between the fluid and the piezoelectric plate when it flows through the tank chamber is reduced, and
The direction of vibration of the piezoelectric plate is oblique to the direction of fluid flow, and when the piezoelectric plate vibrates, it is possible to obtain a component force that presses the fluid toward the discharge port. The speed can be increased and the discharge flow rate of the fluid can be increased.

Embodiment One embodiment of the present invention will be described below with reference to the accompanying drawings.

In the figure, reference numeral 1 denotes a pump body made of synthetic resin and having a substantially square plan view, and a fluid inlet 2 and a discharge outlet 3 are formed on two corresponding sides thereof, and the upper surface of the pump body l. and a circular hole 4.4 is bored in the lower surface, respectively.
As shown in Fig. 3, these circular holes 4.4 are arranged symmetrically in an oblique position with their respective center lines inclined and the depth gradually becoming shallower from the suction port 2 side to the discharge port 3 side. As shown in FIG. 2, in the partition wall 5 between both circular holes 4.4, there is a flow passage 6 whose width gradually increases from the suction port 2 side to the discharge port 3 side. One end and the other end of this flow passage 6 are communicated with the suction port 2 and the discharge port 3 through the through hole 7.8, respectively, and the inlet port 2 and the discharge port 3 are provided with a reverse A stop valve 9.9 is installed.

A pair of piezoelectric plates 11.
11 is stretched, and the tank chamber 1 is placed between the impact electric plates 11 and 11.
0 is formed, and this piezoelectric plate 11 is made by welding electrode coatings to both the upper and lower surfaces of a ceramic plate 12 whose volume changes when a voltage is applied, and then bonding and fixing this to one surface of the diaphragm 14. The diaphragm 1 of this piezoelectric plate 11
A rubber seal ring 15 is fitted on the outer periphery of the pressure plate 11, and the diaphragms 14.14 of the impact electric plate 11 face each other and assume a mating posture, so that both the seal rings 15.15 fit into the circular holes 4, 4.
As shown in FIG. 3, the impulse electric plates 11 and 11 are placed in an oblique position in which the corresponding interval gradually increases from the suction port 2 side to the discharge port 3 side. is taking.

The diaphragm 14.14 of each piezoelectric plate 11 is attached to one electrode rod 18 of a pair of electrode rods 18.18 implanted through the mounting portion 17 of the pump body l, and the other electrode rod 18
Then, the electrode coatings on the outside of each piezoelectric plate 11 are connected with respective lead wires, and furthermore, a ring-shaped suppressor 20.2.0 is applied to the outside of each seal ring 15, and an electrode rod 18 is installed. After covering the upper and lower surfaces of the part 17 with covers 21.2I that protect the connection parts with the lead wires, the pump body 1
Cover plates 22 and 22 are applied to both the upper and lower sides of the cover plate, and are fixed by tightening the four corners with bolts 23 and nuts 24.

Next, the operation of this embodiment will be explained.

When the electrode rods 18.18 are connected to an AC power source and a positive voltage is applied to the ceramic plate 12 of each piezoelectric plate 11, the ceramic plate 12 is distorted and tends to expand in the radial direction, and the ceramic plate 12 While the outer surface of the ceramic plate 12 can freely expand, the inner surface is fixed to and restrained by the diaphragm 14 via the electrode coating, causing the ceramic plate 12 to bulge outward. When a negative voltage is applied to the ceramic plate 12, the piezoelectric plate 11 as a whole swells outward and bends.Conversely, when a negative voltage is applied to the ceramic plate 12, the ceramic plate 12 is distorted in the opposite direction and tends to contract in the radial direction. This is because the inner surface of the plate 12 is constrained.

The ceramic plate 12 is recessed inward, the entire piezoelectric plate 11 is bent inward, and positive and negative voltages are applied alternately to the ceramic plate 12.12, so that both piezoelectric plates 11.11 move in a direction in which their corresponding surfaces are separated from each other. flexing alternately in the direction of approaching
When both piezoelectric plates 11 and 11 are bent in the direction away from each other and the volume of the tank chamber 10 is increased, the check valve 9 of the suction port 2
opens, the check valve 9 of the discharge port 3 closes, and the suction port 2
The fluid is sucked into the flow passage 6 of the tank chamber 10 from the tank chamber 10, and the two piezoelectric plates 11 and 11 are bent in the direction toward each other, and the tank chamber I
When the volume of O decreases, the check valve 9 of the discharge port 3 opens and the check valve 9 of the suction port 2 closes, and the fluid in the flow path 6 is discharged from the discharge port 3. Since the corresponding interval between the pair of piezoelectric plates 11.11 gradually becomes wider from the suction port 2 side to the discharge port 3 side, the fluid flows between both piezoelectric plates 11 and 11.
The frictional resistance generated between the piezoelectric plate 11 and the piezoelectric plate 11 is small when the fluid flows between them, and when both piezoelectric plates 1 bend inward to discharge the fluid, the fluid is pushed toward the discharge port 3 side. A force component is obtained, thus increasing the velocity of the fluid and increasing the discharge flow rate.

In addition, in the above embodiment, the piezoelectric plate 11 is tilted by 2° to 5° on one side so that the intersection angle is 5°, and if it has such an intersection angle, the above-mentioned fluid speed increasing effect can be obtained. However, in order to achieve a greater speed-increasing effect, it is desirable that the intersection angle between the two piezoelectric plates 11 be approximately 10°.

Further, in the above embodiment, since the partition wall 5 is provided in the tank chamber 10 and the volume of the tank chamber 10 is reduced,
After the pump is started, it takes less time for the tank chamber 10 to be filled with fluid, which shortens the start-up time until steady discharge occurs.Furthermore, since the fluid flows straight along the flow path 6, the tank chamber 10 is filled with fluid. This prevents the formation of air pockets due to swirling of the fluid within the fluid flow path 10, and the fluid is discharged at a constant flow rate of 1.1 with small variations. Since it gradually becomes wider toward the side, the frictional resistance generated between it and the side surface of the flow path 6 can be kept small.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway perspective view of a pump body according to an embodiment of the present invention, FIG. 2 is a plan view thereof, and FIG. 3 is a sectional view of the piezo pump of this embodiment.

Claims (1)

[Claims] A pair of piezoelectric plates that are deflected by applying a voltage are stretched over both open ends of a hole made through the pump body, and a tank chamber is formed between the two piezoelectric plates, and the center of the tank chamber is sandwiched between the two piezoelectric plates. A fluid suction port and a fluid discharge port are provided on both sides, and the volume of the tank chamber is alternately increased or decreased by alternately bending both the piezoelectric plates in a direction in which the corresponding surfaces move away from each other and in a direction in which the corresponding surfaces approach each other. In the piezo pump, the fluid sucked into the tank chamber from the suction port is discharged from the discharge port, in which both piezoelectric plates are placed in an oblique position such that the corresponding spacing gradually increases from the suction port side to the discharge port side. A piezo pump characterized by being installed oppositely.