JPH03542Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention relates to a piezo pump, and more specifically to an improvement of a piezo pump that suctions and pumps fluid by the vibration of a piezoelectric vibrator, that is, a piezo vibrator. Regarding.

(B) Prior art A pump using a piezo element vibrates the piezo oscillator by applying a voltage to the piezo oscillator to periodically change the volume of the pump chamber limited by the piezo oscillator. This gives it a pump effect.

A conventional pump of this type is disclosed in, for example, Japanese Unexamined Patent Publication No. 59-41684.
This conventional pump, as shown in FIG.
A pair of disc-shaped piezo oscillators c are installed in the chamber b of the main body a.
are provided facing each other and separated from each other, and their peripheral parts are fixed and held by a holder d, and fluid is passed into the pump chamber through an inlet port f and an outlet port g that communicate with a pump chamber e formed between piezo vibrators c. A check valve h and a check valve i passing from the pump chamber to the outside are provided respectively, and the piezoelectric vibrator is vibrated to suck fluid from an inlet port f and discharge it from an outlet port g.

However, in conventional piezo pumps including the above-mentioned structure, the piezo vibrator is directly exposed to the fluid to be pumped, and therefore, when pumping a conductive liquid such as water, there is a problem that electrical shock may occur due to current leakage. Furthermore, since the peripheral portion of the piezo vibrator is firmly held by the holder, the movement of the piezo vibrator is suppressed and becomes small, resulting in a problem that a sufficient discharge flow rate cannot be obtained.

(c) Problems to be solved by the invention The problems to be solved by the invention are to electrically insulate the piezoelectric vibrator and the fluid to be pumped, and to allow large vibrations of the vibrator to increase the pump discharge flow rate. It is to aim for it.

(d) Means for solving the problem The present invention provides a pair of piezoelectric vibrators facing each other in the pump body, and an inlet port and an outlet port that communicate with the pump chamber formed between the piezoelectric vibrators. In a piezo pump that is provided with a check valve, vibrates the piezo vibrator to change the volume of the pump chamber, and thereby pumps fluid, an insulating coating is provided on at least surfaces facing each other of the piezo vibrator, The body is provided with a pair of annular protrusions around the hole that defines the pump chamber, the tips of which are pointed and protrude in opposite directions, and the annular protrusions are brought into contact with the surface of the insulating coating of the piezo vibrator. and a cover is attached to both sides of the main body, and each cover is provided with an annular protrusion protruding toward the annular protrusion of the main body with a pointed tip and having approximately the same diameter as the annular protrusion of the main body. , the annular protrusion of the cover is brought into contact with the surface of the piezo vibrator on the side opposite to the pump chamber in alignment with the annular protrusion of the main body, and the annular protrusion of the main body and cover contacts the peripheral part of the piezo vibrator. It is configured to support.

(e) Effect In the above configuration, when a voltage is applied to the pair of piezo vibrators simultaneously, the piezo vibrators vibrate in such a way that their centers alternate between protruding toward the pump chamber and protruding toward the opposite side of the pump chamber. The volume of the pump chamber is changed periodically. Fluid is then drawn into the pump chamber through the inlet port and expelled from there through the outlet port.

(f) Embodiments Examples of the piezo pump of the present invention will be described below with reference to the drawings.

1 and 2, a piezo pump 1 according to this embodiment is shown. This piezo pump 1 includes a main body 2 having a circular stepped hole 21 passing through it, an inlet port 22 and an outlet port 23 communicating with the hole 21, and a pair of piezo vibrators ( (hereinafter simply referred to as a vibrator) 3, a cover 4 that closes a hole 21, and check valves 5 (5a, 5b) provided in an inlet port 22 and an outlet port 23.

A pair of annular protrusions 24 are formed in the main body 2 in the hole 21 and protrude in opposite directions toward the open end. The cross-sectional shape of the annular protrusion 24 has a pointed tip to minimize contact with the vibrator 3.
Inlet port 22 and outlet port 23 open into hole 21 between both annular projections 24 .

The vibrator 3, as shown in detail in FIG.
It has a known structure in which a piezo element 32 is bonded to one surface of a circular diaphragm 31, and an insulating coating 33 is further applied to the surface of the diaphragm 31 on the side opposite to the piezo element. The vibrator 3 is housed in the hole 21 with the insulating coating in contact with the annular protrusion 24 .

As shown in FIG. 3, the cover 4 is formed with an annular protrusion 42 that is fitted into the hole 21 of the main body 2, and the cross-sectional shape of the tip 43 is similar to that of the annular protrusion 2.
Like 4, it is pointed. Annular projections 24 and 42
The tip edges of the oscillators are formed into circles with approximately the same diameter, so that when the oscillator 3 is supported, the oscillator can vibrate to the maximum extent possible. When the cover 4 is fixed to the main body 2 as shown in FIG. 1, the tip 43 of the annular projection 42 of the cover 4 supports the vibrator 3 so that it can vibrate while being pressed against the annular projection 24.

The check valve 5 has a hollow cone 51 made of a flexible material so that the wall becomes thinner toward the tip, and a plurality of slits 52 are provided at the tip of the cone 51 at intervals in the circumferential direction. When the fluid flows in the direction of the arrow, the slitted tip opens to allow the fluid to flow, and in the opposite case it closes to prevent the flow. Note that the check valve is not limited to the structure shown in the drawings, but may have a known structure such as one using a ball and a spring.

In the above configuration, when a predetermined voltage is simultaneously applied between the pair of lead wires 34 and 35 of the pair of vibrators 3, the center portion of the vibrator protrudes toward the pump chamber 25, which is limited between the vibrators. The pump chamber 25 vibrates by repeating the state of protruding in opposite directions alternately, thereby periodically changing the volume of the pump chamber 25. and when the volume of the pump chamber increases, the inlet port 22
Fluid flows from the pump chamber 25 into the pump chamber 25 and is expelled from the pump chamber through the outlet port as the volume of the pump decreases.

Note that the insulating coating may be provided all around the vibrator.

(g) Effects According to the present invention, the following effects can be achieved.

Since the insulating coating is provided on the surface of the vibrator on the pump chamber side, the fluid to be pumped and the vibrator are insulated, thereby preventing electric leakage accidents.

Various fluids can be handled by changing the type of insulation coating.

The amplitude of the vibrator can be increased and the discharge flow rate can be increased.

[Brief explanation of drawings]

Fig. 1 is a sectional view of an embodiment of the piezo pump according to the present invention, Fig. 2 is a plan view of the piezo pump shown in Fig. 1 with the upper cover and vibrator removed, and Fig. 3 is a perspective view of the cover. , FIG. 4 is a side view of a piezo vibrator, and FIG. 5 is a sectional view showing an example of a conventional piezo pump. 1: Piezo pump, 2: Main body, 21: Hole, 2
2: Inlet port, 23: Outlet port, 24: Annular protrusion, 25: Pump chamber, 3: Piezo vibrator, 4:
Cover, 42: Annular protrusion, 5: Check valve.

Claims (1)

[Scope of utility model registration request] A pair of piezo oscillators are provided in the pump body in opposition to each other, and check valves are provided in the inlet and outlet ports that communicate with the pump chamber formed between the piezo oscillators, and the piezo oscillators are vibrated. In a piezo pump that changes the volume of the pump chamber and thereby pumps fluid, an insulating coating is provided on at least the surfaces facing each other of the piezo vibrators, and a tip is provided on the main body around a hole that defines the pump chamber. A pair of annular protrusions are provided that are sharpened and protrude in opposite directions, and the annular protrusions are brought into contact with the surface of the insulating coating of the piezo vibrator. Covers are attached to both sides of the main body, and the covers are attached to each other. Each is provided with an annular protrusion that protrudes toward the annular protrusion of the main body with a pointed tip and has approximately the same diameter as the annular protrusion of the main body, and the annular protrusion of the cover is connected to the anti-pump of the piezo vibrator. A piezo pump characterized in that the piezo vibrator is brought into contact with a chamber-side surface in alignment with an annular protrusion of the main body, and the annular protrusion of the main body and cover supports a peripheral portion of the piezo vibrator.