JP2887678B2 - Piezo pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] Industrial Applicability The present invention relates to an improvement of a piezoelectric pump using a longitudinal effect type piezoelectric actuator.

Conventional technology Application was filed on October 15, 1985 (Japanese Patent Application No. 60-230256),
In the micropump disclosed in Japanese Patent Application Laid-Open No. 62-91675 on April 27, 1987, the volume of the pump chamber is large, the pump chamber is gas, and the displacement of the diaphragm is about several hundred microns. And the generation of negative pressure is so small that the liquid cannot be sucked up.

An application was filed on January 8, 1986 (Japanese Patent Application No.
No., published a patent application on July 15, 1987 (Japanese Patent Application Laid-Open No.
Even if the pump chamber size is reduced and the pump chamber volume change rate is increased, as in the case of a diaphragm pump, the part with smaller dimensions and the direction of flow will change unless a liquid flow path is provided. In this part, the distribution of the flow velocity is disturbed to generate a vortex, which lowers the pump efficiency or induces the generation of bubbles, thereby restricting the increase in the flow rate.

Problems to be Solved by the Invention The present invention reduces the volume of the pump chamber by reducing the volume of the pump chamber and preventing an increase in flow path resistance due to the reduction of the volume of the pump chamber by providing a liquid flow path. An object of the present invention is to provide a piezoelectric pump in which the rate of change is increased and the suction pressure is improved by increasing the negative pressure of the pump chamber when the pump chamber is gaseous.

Means for Solving the Problems In order to solve the above problems, the present invention provides a piezoelectric pump including a lid and a casing, wherein the lid has an inlet and an outlet. A suction-side check valve is provided in the hollow portion communicating with the suction port, and a discharge-side check valve is provided in the hollow portion communicating with the discharge port, and the suction-side check valve and the discharge-side check valve are provided. A diaphragm body having a surface covered with a stretchable elastic member formed on the surface of the base portion is attached so as to cover one side of the pump chamber facing the inside, and an L-shaped fixing member and an L-shaped fixing member fixed to the casing portion are provided in the casing portion. A leaf spring fixed to the mold fixing member, a lever attached to an open end of the leaf spring, a support member fixed perpendicularly to the other end of the lever, an L-shaped fixing member close to the leaf spring and the lever Vertical effect type piezoelectric actuator fixed between A magnifying mechanism comprising a spring having one end locked to the support member and the other end locked to the L-shaped fixing member, fixing the base of the diaphragm body and the support member, and a suction-side check valve. And a concave portion provided below the discharge-side check valve is connected to each other by a flow path.

Operation The operation of the present invention will be described below.

A voltage (the waveform of the voltage in this case is a sine wave, a rectangular wave, a triangular wave, a sawtooth wave, etc.) is applied to the longitudinal effect type piezoelectric actuator 11 of the enlargement mechanism 2b housed in the casing 2a of the casing portion 2. When the voltage is applied, the vertical effect type actuator 11 vibrates, and the vibration is magnified by the lever 14 of the magnifying mechanism 2b, causing the lever 14 to vertically move the U-shaped support member 27a fixed to the lower end of the support member 27, The diaphragm main body 9 attached to the U-shaped support member 27a is moved up and down. When the diaphragm body 9 moves downward, the pressure in the pump chamber 8 becomes negative, so that the discharge-side check valve 6a is closed, the suction-side check valve 5a is opened, and the liquid is pumped. When the diaphragm body 9 moves upward, the inside of the pump chamber 8 becomes positive pressure, so that the suction-side check valve 5a is in a closed state, and the liquid passes through the flow path and is checked on the discharge side. The valve 6a is opened and the liquid is discharged from the discharge port 4.
Discharge more.

The spring 13 pulls the U-shaped support member 27a downward. That is, the vertical effect type piezoelectric actuator 11 cannot generate a force in the contraction direction. In other words, it is weak against tensile stress.
It is helping eleven.

As described above, the suction and discharge of the liquid are repeated by the vertical vibration of the vertical effect type piezoelectric actuator 11.

Embodiment FIGS. 1 to 7 are views showing an embodiment of a piezoelectric pump according to the present invention. Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a longitudinal sectional view of a first embodiment of the piezoelectric pump according to the present invention. Reference numeral 1 is a cover, and reference numeral 2 is an enlargement mechanism.
2b is a casing part that houses 2b.

A suction port 3 and a discharge port 4 are provided at an upper portion of the lid portion 1, and a hollow portion 5 having a diameter slightly larger than the diameter of the suction port 3 is formed below the suction port 3. Is the suction side check valve
5a is attached. Similarly, a hollow portion 6 having a diameter larger than the diameter of the discharge port 4 is formed below the discharge port 4, and a discharge-side check valve 6a is attached to the bottom of the hollow portion 6.

A pump chamber 8 is formed between the suction-side check valve 5a and the discharge-side check valve 6a and the diaphragm main body 9 covered with a stretchable elastic member such as rubber. A passage 7 is formed, and recesses 5b and 6b are formed below the suction-side check valve 5a and the discharge-side check valve 6a, respectively. The flow channel 7 through which the liquid flows is formed between the concave portion 5b and the concave portion 6b, and the concave portion 5b and the concave portion 6b are connected by the flow channel 7.

The concave portions 5b, 6b formed by the suction side concave portion 5b, the flow path 7, and the discharge side concave portion 6b are formed in the minimum concave portions 5b, 6b in accordance with both the check valves 5a, 6a and the movement of the liquid. The reason for this is to prevent the pump chamber 8 from having an unnecessary volume by being formed to the minimum.

By providing the flow path 7 between the concave portion 5b and the concave portion 6b, the flow path resistance increases when the volume of the pump chamber 8 is small, but the flow path resistance does not increase.

With the pump chamber 8 configured as described above, when the volume of the pump chamber 8 is the maximum, the distance between the diaphragm main body 9 and the flow path 7 is only 200 to 500 microns. When the diaphragm body 9 reciprocates once with a displacement of 200 microns, 0.4
It has a sufficient suction force to generate a negative pressure lower than the atmospheric pressure.

The diaphragm main body 9 used in the present invention is a third main body.
As shown in the figure, the surface of the metal plate 9a is covered with a film 10 by a stretchable elastic member such as rubber, and a plurality of protrusions 10a, 10b, and 10c are provided on the outer peripheral surface of the film 10 to protrude. A groove 10d is formed on the outer peripheral back surface.

FIG. 4 shows another embodiment of the diaphragm main body 9.

Since the outer peripheral portion where the projections 10a, 10b, and 10c of the coating 10 of the diaphragm body 9 formed in this way are fixed,
The whole diaphragm main body 9 moves up and down in parallel according to the vibration of the piezoelectric actuator 11. For this reason, spherical displacement and conical displacement are not performed unlike the conventional diaphragm.

Reference numerals 20 and 21 are fixing bolts for fixing the lid 1 to the casing 2. In the present embodiment, an umbrella valve is used as the check valve, but it is not necessary to limit to the umbrella valve, and another valve may be used.

The enlargement mechanism 2b housed in the casing 2 mounts the leaf spring 15 in the L-shaped fixing member 12 and fixes the lower end of the longitudinal effect type piezoelectric actuator 11 to the L-shaped fixing member 12,
The upper end of the vertical effect type piezoelectric actuator 11 is
Is fixed to the inside of the lever 14 attached to the fixing bolt 22. Fixing bolt on the tip of the leaf spring 15
A U-shaped support member 27a having left and right support members 27b and 27c supporting the diaphragm main body 9 is fixed to the distal end portion of the lever 14 fixed by 23 via the support member 27.

A spring 13 is attached to a lower end of the support member 27, and a lower end of the spring 13 is fixed to the L-shaped fixing member 12 by a bolt 26.

FIG. 2 is a partial longitudinal sectional view taken along the line AB of FIG. 1 showing a piezoelectric pump according to the present invention. That is, the U-shaped support member 27
FIG. 3 is a view showing a state in which the diaphragm main body 9 is supported by a, and is a vertical cross-sectional view taken along line AB in FIG. 1, and the diaphragm main body 9 is a right support member 27c and a left support member 27b of a U-shaped support member 27a. Supported by

FIG. 1a shows a longitudinal sectional view of a second embodiment of the piezoelectric pump according to the present invention. As shown in FIG. 1a, a suction port protruding portion 3a is protruded in a hollow portion 5 on the suction port 3 side to form an air storage portion 5c, and a discharge port is also formed in a hollow portion 6 on the discharge port 4 side. The protrusion 4a is protruded to form the air reservoir 6c.

FIG. 5 is a view showing a third embodiment of the piezoelectric pump according to the present invention, and is a schematic view in which a part is omitted. In this embodiment, the casing portion 2 accommodating the enlargement mechanism 2b is provided with a pump chamber 8 or the like. It is arranged right beside a certain lid 1. In this example, the support member 27 supports the diaphragm main body 9. One end of a spring 13 is fixed to an L-shaped fixing member 12, and the other end of the spring 13 is fixed to a lever 14.

By arranging the enlargement mechanism 2b horizontally in this manner, there is an advantage that the size can be reduced. The longitudinal section of the lid 1 of this embodiment is the same as that shown in FIG.

FIGS. 6 and 7 show a fourth embodiment of the piezoelectric pump according to the present invention.
It is the schematic diagram which showed the Example and partially omitted. Seventh
The figure is a longitudinal sectional view of a fourth embodiment of the piezoelectric pump according to the present invention.

In the present embodiment, the suction port 3 and the suction-side check valve 33 are provided below the pump chamber 8, and a ball valve is used as the check valve. The discharge port 4 and the discharge-side check valve 32 are provided above the pump chamber 8, and a ball valve is used as the check valve. The liquid flow path 7 and the pump chamber 8 are also formed in the vertical direction, and the casing jig 2 containing the enlargement mechanism 2b is also provided in the horizontal direction. Support member 27 fixed to lever 14
Supports the diaphragm body 9, one end of a spring 13 is locked to one end of the support member 27, and the other end of the spring 13 is fixed to a mounting plate 25a fixed to the L-shaped fixing member 12. Locked to the mounting plate 25a. With this configuration, the discharge of air bubbles is facilitated.

[Effects of the Invention] Since the present invention has the above-mentioned configuration, liquid can be sucked up without priming.

In addition, a vertical effect type piezoelectric actuator is driven at 50Hz
In the case of driving at a speed, there is an effect that a flow rate of 2 liter / min can be obtained.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a first embodiment of a piezoelectric pump of the present invention, FIG. 1a is a longitudinal sectional view of a second embodiment of the piezoelectric pump of the present invention, and FIG. 2 is a piezoelectric pump of the present invention. 1 is a partial longitudinal sectional view taken along the line AB of FIG. 1, FIG. 3 is a longitudinal sectional view of a diaphragm used in the piezoelectric pump of the present invention, and FIG. 4 is used in a piezoelectric pump of the present invention. FIG. 5 is a longitudinal sectional view of another example of the diaphragm shown in FIG. 5, FIG. 5 is a perspective view of a main part of a third embodiment of the piezoelectric pump according to the present invention, and FIG. FIG. 7 is a perspective view of a main part of the embodiment, and FIG. 7 is a longitudinal sectional view taken along line BC in FIG. DESCRIPTION OF SYMBOLS 1 ... Lid part, 2 ... Casing part 2a ... Casing hollow part, 4 ... Discharge part 4a ... Discharge port protruding part, 5, 6 ... Hollow part 5a ... Suction side check valve, 5b, 6b ... Concave part 5c ... Suction side air Reservoir, 6a ... Discharge side check valve 6c ... Discharge side air reservoir, 7 ... Flow path 8 ... Pump chamber, 9 ... Diaphragm body 10 ... Coating, 10a-10c ... Convex part 10d ... Groove part, 11 ... Vertical effect type Piezoelectric actuator 12 ... L-shaped fixing member, 13 ... Spring 14 ... Lever, 15 ... Leaf spring 16-19 ... O-ring, 20, 21 ... Fixing bolt 22, 23 ... Fixing bolt, 24 ... Fixing bolt 25 ... Spring lower end, 25a ... Mounting plate 26 ... Bolt, 27 ... Support member 27a ... U-shaped support member, 27b ... Left support member 27c ... Right support member, 28-31 ... Bolt 32 ... Discharge side check valve, 33 ... Suction side check valve

Continuation of the front page (72) Inventor Hiroyuki Igawa 1-16-1 Minakugahara, Ota-ku, Tokyo Inside Nippon Keiki Seisakusho Co., Ltd. (56) References JP-A-60-98182 (JP, A) JP-A-53-106909 (JP, A) Japanese Utility Model Showa 61-103580 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) F04B 43/06, 9/00

Claims (5)

(57) [Claims] 1. A piezoelectric pump comprising a lid and a casing, wherein the lid is provided with a suction port and a discharge port, and a hollow part communicating with the suction port is provided with a suction-side check valve and a discharge port. A discharge-side check valve is provided in each of the hollow portions communicating with the outlet, and covers one side of the pump chamber where the suction-side check valve and the discharge-side check valve face each other. A diaphragm main body having a coating formed thereon is attached. Inside the casing, an L-shaped fixing member fixed to the casing, a leaf spring fixed to the L-shaped fixing member, and an open end of the leaf spring are attached. A lever, a supporting member fixed orthogonally to the other end of the lever, and
A diaphragm effect type piezoelectric actuator fixed between the mold fixing member and the lever, and an enlargement mechanism comprising a spring having one end locked to the support member and the other end locked to the L-shaped fixing member; A base portion of the piezoelectric pump and the support member are fixed, and concave portions provided below the suction-side check valve and the discharge-side check valve are connected by a flow path. 2. The piezoelectric pump according to claim 1, wherein the casing is disposed right beside the lid. 3. The support member according to claim 1, wherein the left and right support members of the U-shaped support member are fixed to the base of the diaphragm main body, and the U-shaped support member is attached to the vertical portion of the support member. Piezo pump. 4. The diaphragm main body according to claim 1, wherein a plurality of protrusions are formed on the outer peripheral surface of the coating of the diaphragm main body, and a concave portion is formed on the outer peripheral back surface of the coating. The piezoelectric pump according to any one of the above. 5. A suction-side air reservoir is formed by projecting a suction-port protrusion from a hollow portion communicating with the suction port.
5. The piezoelectric pump according to claim 1, wherein a discharge-side air reservoir is formed by projecting a discharge-port protruding portion also in a hollow portion communicating with the discharge port.