JPH0447193A - Pump using bimorph displacement element - Google Patents

Abstract

PURPOSE:To prevent the generation of pulsation to discharge flow discharged from the discharge opening of a casing by converting the vibration of a bimorph displacement element using a lever member so as to enlarge the discharge quantity a fluid, and disposing cylinders and pistons in pairs. CONSTITUTION:When a current is applied to plural piezoelectric ceramic plates 10a, 10b, these are expanded alternately, so that alternate bending displacement is generated to a bimorph displacement element 10 as a whole. As a result, a vibrating part 10e at one end of an elastic shim 10c is vibrated laterally with a fixed end part 10d as a fulcrum, and a connecting member 14 is also vibrated laterally. At the same time, one end part 9b of a lever member 9 is lifted with a center part 9a as a fulcrum and the other end part 9c is lowered, and thereby one piston 7 is lifted and the other piston 8 is lowered. Accordingly, a fluid taken in from an inlet 3 flows into a cylinder 5 and a fluid in a cylinder 6 flows out from a discharge opening 4.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a pump using a pi-morph displacement element.

[Prior Art] Conventionally, pumps using bimorph displacement elements have been developed for the purpose of making devices smaller and lighter or saving energy.

As such a pump, for example, the device shown in FIG. 3 is known. This pump 20 has a fluid inlet 2 at one end.
A cylindrical cylinder 21 in which a discharge port 1a and a discharge port 21b are formed.
, a piston 22 slidably disposed within the cylinder 21, a bimorph displacement element 23 having one end 23a fixed to the wall of the cylinder 21 and the other end serving as a vibrating part 23b, and the bimorph In the vibrating part 23b of the displacement element 23,
A substantially disc-shaped resonance plate 24 is fixedly supported with a supporting protrusion 24a protruding from the back surface thereof, and is interposed between the resonance plate 24 and the piston 22 to support the piston 22. and a spring 25 for resilient support.

Therefore, according to this pump 20, first, by vibrating the vibrating portion 23b of the bimorph displacement element 23, the resonance plate 24 is vibrated. As a result, the piston 22 urged by the spring 25 slides inside the cylinder 21, and when the piston 22 slides in the distal direction, the check valve 27 disposed at the discharge port 21b is opened. When fluid is discharged and the piston 22 slides toward the rear end, a check valve 26 disposed at the suction port 21 a is opened to suck fluid into the cylinder 21 .

[Problems to be Solved by the Invention] However, the pump 20 has the following problems.

That is, the structure uses the resonance plate 24 and the spring 25 to amplify the vibration of the bimorph displacement element 23 and enlarge the sliding range of the piston 22. Therefore, since the amount of fluid discharged is proportional to the strength of the spring 25, the elastic force of the spring 25 must be increased in order to increase the amount of fluid discharged. However, if the elastic force of the spring 25 is too strong, even if the bimorph displacement element 23 is vibrated, the resonant plate 2
4 does not vibrate, and conversely there is a problem that fluid cannot be discharged.

Further, when the piston 22 is sliding in the suction direction, the fluid is not discharged and there is a problem that pulsation occurs in the discharge flow.

The present invention solves these problems, makes the sliding range of the piston larger than conventional ones, and makes it possible to increase the amount of fluid discharged with a simple structure. The object of the present invention is to provide a pump using a bimorph displacement element with a new structure that can obtain a flow.

[Means for Solving the Problems] In order to achieve the above object, the bimorph displacement element of the present invention includes a casing having a discharge port and a suction port, a branch pipe portion provided in communication with the discharge port, and a distal end discharge portion. a cylinder connected to the branch pipe and disposed within the casing;
It has a fluid passage hole, and a check valve for opening and closing the fluid passage hole is attached to the piston disposed in the cylinder, and the end part is connected to the piston rod of the piston, and the approximately center part is connected to the piston rod of the piston. a lever member disposed by being pivoted at an arbitrary position within the casing; and a bimorph displacement element having one end fixed at an arbitrary position within the casing and a vibrating section at the other end connected to the lever member. , the bimorph displacement element is energized and vibrated to rotate the lever member about its substantially central portion as a fulcrum, and the piston is slidably provided within the cylinder. Features.

In a preferred embodiment of the present invention, the cylinders and pistons are arranged in pairs, and the piston rods of each piston are connected to both ends of the lever member, and the pistons are slid alternately. It will be possible.

[Function] In this configuration, when the bimorph displacement element is energized, the vibrating part of the bimorph displacement element vibrates. This results in
The lever member rotates about its substantially central portion as a fulcrum, and a piston connected to an end of the lever member via a piston rod slides within the cylinder.

When the piston slides in the cylinder toward the rear end, the check valve opens to suck in fluid from an inlet formed in the casing. On the other hand, when the piston slides in the cylinder toward the distal end, the reverse valve closes and fluid is discharged to the outside from the discharge port.

At this time, since the piston is slid by the lever member, the amount of sliding of the piston relative to the amount of vibration of the bimorph displacement element is extremely large due to the lever principle.

Moreover, in a preferred embodiment of the present invention, since the fluid is alternately discharged from the distal end discharge portions of the two cylinders, no pulsation occurs in the discharge flow flowing out from the discharge port of the casing.

[Example] Hereinafter, the present invention will be explained in more detail based on the example shown in the drawings.

In the figure, l indicates a pump using the bimorph displacement element of this embodiment, which mainly includes a casing 2, a cylinder 5,
6, a piston 7.8, a lever member 9, and a bimorph displacement element IO.

The casing 2 has an inlet 3 and an outlet 4 at appropriate locations.
is formed. Further, from the discharge port 4, a branch pipe portion 4a,
4b is formed into a branch by, for example, drilling a wall portion of the casing 2, and the branch pipe portions 4a, 4b
Check valves 4c and 4d are disposed in the middle.

The cylinders 5 and 6 are disposed inside the casing 2 so that their distal end discharge portions 5a and 6a are connected to branch pipe portions 4a and 4b branched from the discharge port 4, respectively.

Note that the cylinder 5.6 may be molded integrally with the casing 2, or may be constructed as a separate member.

A piston 7.8 is slidably inserted into the rear end openings 5b, 6b of the cylinder 5.6. Also,
This piston 7.8 has fluid passage holes 7a, 8a, respectively.
A check valve 7b is provided with a check valve 7b which opens and closes the fluid passage holes 7a and 8a.

8b is the piston 7.8b, for example, as shown in FIG.
It is attached to the tip surface of 8. Furthermore, piston rods 7c and 8c are provided protruding from the rear end side of the piston 7.8 and are connected to a lever member 9, which will be described later.

The lever member 9 has a substantially central portion 9a serving as a fulcrum that is freely rotatably pivoted by a shaft pin 11 onto a protrusion 2a provided on the inner surface of the casing 2 facing the rear end openings 5b and 6b of the cylinders 5 and 6. It is supported and arranged. And both ends 9b of this lever member 9.

9c is the piston rod 7c as described above.

The ends of 8c are each pivoted by a pin 12.13.

The bimorph displacement element 10 is sandwiched between two piezoelectric ceramic plates 10a and 1Ob that expand and contract in the length direction, and one end or both ends are formed as shown in the drawing. The piezoelectric ceramic plate 1
The elastic shim 10c has a length that protrudes from between 0a and 1Ob. Further, lead wires (not shown) are drawn out from the piezoelectric ceramic plates 1'Oa and 10b, respectively, and are connected to an external power source or a battery disposed at an appropriate position within the casing 2.

This bimorph displacement element 10 is arranged so as to be substantially perpendicular to the arrangement direction of the lever member 9, and one end 10d of the elastic shim loc is attached to the wall of the casing 2 on the side where the cylinder 5.6 is fixed. It is fitted and fixed into the provided recess 2b, and the other end vibrating section 10e is connected to the lever member 9. Specifically, as shown in FIG.
, the other end vibrating portion 10 of the elastic shim 10c is inserted into the vertically long hole 9d bored between the fulcrum 9a and the elastic shim 10c.
The bifurcated connecting member 14 holding the e is connected to the movable bottle 9
This is a structure in which f is inserted and connected.

The pump 1 using the bimorph displacement element of this embodiment operates as follows.

First, when a current is passed through the piezoelectric ceramic plates 10a and 10b, when one of them 10a expands, the other 10b contracts.
Since one side 10a contracts when the other side 10b extends, the bimorph displacement element 10 as a whole alternately undergoes bending displacement.

As a result, the elastic shim 10c uses the fixed end portion 10d as a fulcrum, and the other end vibrating portion 10e vibrates from side to side in the drawing. As a result, the connecting member 14 holding the other end vibrating portion 10e also vibrates left and right.

When the other end vibrating portion 10e and the connecting member 14 vibrate to the right in the drawing, the movable bottle 9f presses the right side hole wall of the elongated hole 9e, so the lever member 9
is used as a fulcrum to move one end 9b upward in the drawing and the other end 9c downward to slide one piston 7 toward the rear end 5b of the cylinder, and move the other piston 8 toward the cylinder 6. slide it toward the distal end discharge part 6a side. Therefore, the check valve 7b of one piston 7 is opened, and the fluid taken in from the suction port 3 passes through the fluid passage hole 7a and flows into the cylinder 5, and the other piston 8 is opened. Since cylinder 8b closes, cylinder 6
The fluid inside is sent out to the branch pipe part 4b, and further the fluid is sent to the branch pipe part 4b.
The check valve 4d disposed in is opened to send fluid out from the discharge port 4. At this time, the reverse valve 4c disposed in the other branch pipe section 4a is closed, so that the fluid is discharged only from the discharge port 4 without flowing into the other branch pipe section 4a.

On the other hand, when the bimorph displacement element 10 vibrates to the left in the drawing, unlike the above case, the movable bin 9f moves to the elongated hole 9e.
The other piston 8 is moved upward to suck fluid into the cylinder 6 by pressing the left side hole wall of the cylinder 5, while the other piston 7 is slid toward the distal end discharge portion 5a of the cylinder 5, and the Fluid is discharged from.

At this time, the amount of fluid discharged is determined by converting the amplitude of the bimorph displacement element 10 into the sliding amount of the piston 7.8 by the lever member 9. The amount of movement is very large, and the amount of fluid discharged is large compared to conventional ones.

Furthermore, since the two cylinders and pistons are operated alternately, fluid is constantly discharged from the discharge port 4.

Note that the bomb using the bimorph displacement element of the present invention is not limited to the above-described embodiments. for example,
In the above embodiment, two cylinders 5.6 and two pistons 7.8 were arranged in pairs to prevent pulsation from occurring in the fluid discharged from the discharge port 4. It is also possible to have a structure in which a weight member or the like is attached to one end of the member 9 to discharge fluid. Also in this case, the amount of fluid discharged is larger than that of the conventional method.

[Effects of the Invention] According to the pump using the bimorph displacement element of the present invention,
Since the vibration of the bimorph displacement element is converted using a lever member, the amount of fluid discharged is larger than that of the conventional type. Further, by arranging the cylinder and the piston in pairs, it is possible to prevent pulsation from occurring in the discharge flow discharged from the discharge port of the casing.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an embodiment of a pump using the bimorph displacement element of the present invention, Fig. 2 is a partially enlarged view for explaining the operation of the members, and Fig. 3 is a cross-sectional view of a conventional pump. FIG. 1... Pump 2... Casing 3... Suction port 4... Discharge port 5.6... Cylinder 7.8... ... Piston 9 ... Lever member 10 ... Bimorph displacement element

Claims (2)

[Claims] (1) A casing having a discharge port and a suction port, a branch pipe section provided in communication with the discharge port, a cylinder whose distal end discharge section is communicatively connected to the branch pipe section and disposed within the casing, and a fluid. A piston having a passage hole and a check valve for opening and closing the fluid passage hole is attached, and the piston is disposed within the cylinder. a lever member disposed by being pivoted at an arbitrary position within the casing; a bimorph displacement element having one end fixed at an arbitrary position within the casing and a vibrating section at the other end connected to the lever member; The bimorph displacement element is energized and vibrated to rotate the lever member about its substantially center portion as a fulcrum, and the piston is slidably provided within the cylinder. A pump using a bimorph displacement element. (2) A pair of each of the cylinders and two pistons is provided, and a piston rod of each piston is connected to both ends of the lever member, so that the pistons are slidably provided alternately. A pump using the bimorph displacement element described above.