JP2019112970A - pump - Google Patents

Abstract

To provide a pump capable of stably discharging a fluid from a discharge port regardless of viscosity of the fluid.SOLUTION: A pump 11 includes: a case 12 having a fluid chamber 19 communicating with a suction port 17 into which a fluid is suctioned and a discharge port 18 from which the fluid is discharged, a storage chamber 20 located adjacent to the fluid chamber 19, and an annular seal surface 26a located at a border between the fluid chamber 19 and the storage chamber 20; and an actuator 22 which is stored in the storage chamber 20 and has a dielectric layer made of a dielectric elastomer and a pair of electrode layers which face each other across a center part of the dielectric layer and are made of a conductive elastomer. A surface in the actuator 22 facing the fluid chamber 19 is formed as a fluid chamber formation surface 22a forming a part of a wall surface forming the fluid chamber 19. A surface in the actuator 22 which is opposite to the fluid chamber formation surface 22a is fixed to a bottom surface in the case 12. A peripheral edge part at the fluid chamber formation surface 22a side in the actuator 22 cooperates with the seal surface 26a to seal a space between the fluid chamber 19 and the storage chamber 20.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a pump utilizing an actuator made of dielectric elastomer.

  Conventionally, as this type of pump, for example, a diaphragm type pump as shown in Patent Document 1 is known. Such a pump includes a housing, a diaphragm that divides the inside of the housing into a first chamber and a second chamber, and a spring that connects a central portion of the diaphragm and an inner wall of the second chamber facing the central portion. There is. The diaphragm is composed of a film type of electrostrictive stretchable polymer (actuator) which enables expansion and contraction of the area accompanying contraction and expansion in the thickness direction by fluctuation of applied voltage and current.

  The first chamber is formed with an inlet and an outlet opposite to each other along the diaphragm. The suction port is provided with a suction valve body that allows fluid to enter the first chamber from the outside and prevents fluid from flowing out of the first chamber. On the other hand, at the discharge port, a discharge valve is disposed which prevents the inflow of fluid from the outside into the first chamber and allows the fluid to flow out of the first chamber.

  Then, by repeating application and stop of voltage or current to the electrostrictive stretchable polymer constituting the diaphragm, the stretchable force of the electrostrictive stretchable polymer and biasing force of the spring cause the diaphragm to be between the first chamber and the second chamber. Reciprocating at As a result, the supply of fluid from the outside to the first chamber through the suction port and the discharge of fluid from the first chamber to the outside through the discharge port are performed.

JP 2001-286162 A (FIG. 6)

  By the way, in the pump as described above, the peripheral portion of the diaphragm is supported by the housing and the central portion of the diaphragm is connected to the inner wall of the second chamber via a spring. The part between is separated from the housing. For this reason, when the viscosity of the fluid is high or the discharge pressure is high, the diaphragm receives the reaction force from the fluid when it presses the fluid in the first chamber, and the fluid expands. As a result, since the diaphragm does not perform the desired operation, there is a problem that the discharge of the fluid from the outlet becomes unstable.

  The present invention has been made in view of the problems existing in such prior art. The object is to provide a pump capable of stably discharging the fluid from the outlet regardless of the viscosity of the fluid.

Hereinafter, the means for solving the above-mentioned subject and its operation effect are described.
A pump for solving the above problems includes: a fluid chamber in communication with both an inlet through which fluid is sucked and an outlet through which the fluid is drained and capable of containing the fluid, and a storage chamber adjacent to the fluid chamber. A case having a ring-shaped sealing surface located at the boundary between the fluid chamber and the storage chamber, a pair of housings housed in the storage chamber and facing each other across the central portion of the dielectric layer and the dielectric layer made of dielectric elastomer. An actuator having an electroconductive elastomer electrode layer, a first valve capable of opening and closing the suction port, and a second valve capable of opening and closing the discharge port, and a surface of the actuator facing the fluid chamber is The fluid chamber forming surface includes a central portion of at least a portion of the actuator and forms a portion of a wall surface forming the fluid chamber, and the surface of the actuator opposite to the fluid chamber forming surface is Is fixed to the inner surface of the case, the peripheral portion of said fluid chamber forming surface side of the actuator, and summarized in that in cooperation with the sealing surface seals between said storage chamber and said fluid chamber.

  According to this configuration, when a voltage is applied to the actuator, the fluid chamber forming surface is elastically deformed quickly so as to be recessed from a flat state, and when the application of the voltage to the actuator is stopped, the fluid chamber forming surface is not deformed before the elastic deformation. It will be restored to its flat state quickly. In this case, since the surface on the opposite side of the fluid chamber forming surface of the actuator is fixed to the inner surface of the case, even when the viscosity of the fluid is high, the fluid chamber forming surface of the actuator is elastically deformed from the elastically deformed state so as to be depressed. It is stably restored to its original original flat state. Therefore, even when the viscosity of the fluid is high, the fluid in the fluid chamber can be smoothly pressurized by the fluid chamber forming surface, so that the fluid can be stably discharged from the outlet regardless of the viscosity of the fluid.

  In the pump, the case includes: a fluid chamber case that defines the fluid chamber; a storage chamber case that defines the storage chamber; and an annular seal member that protrudes and is fixed to the fluid chamber case. It is preferable that the sealing surface be constituted by a surface on the storage chamber side of the sealing member.

According to this configuration, since the fluid chamber can be widened, the first valve and the second valve can be easily incorporated into the fluid chamber.
In the pump, it is preferable that the fluid chamber formation surface be formed of a protective layer formed of a material having a permeability to the fluid lower than that of the material forming the dielectric layer.

According to this configuration, since the fluid chamber formation surface is formed by the protective layer, even a material having low resistance to fluid can be used as a material for forming the dielectric layer.
In the pump, the dielectric layer is preferably formed of a crosslinked polyrotaxane.

  According to this configuration, since the dielectric constant is higher than when the dielectric layer is formed of, for example, silicone elastomer, the expansion ratio of the actuator to the applied voltage can be increased. Therefore, even when the voltage applied to the actuator is small, a relatively large amount of fluid can be transferred.

In the pump, it is preferable that the first valve and the second valve be configured by an elastic body that opens and closes by being elastically deformed by a pressure change of the fluid chamber.
According to this configuration, the sound generated by the opening and closing of the valve body can be reduced.

  According to the present invention, the fluid can be stably discharged from the outlet regardless of the viscosity of the fluid.

BRIEF DESCRIPTION OF THE DRAWINGS The perspective view which shows the pump of one Embodiment. FIG. 2 is a cross-sectional view of FIG. The cross-sectional schematic diagram of the actuator in a pump. Sectional drawing which shows a state when fluid is inhaled from the suction port of a pump. Sectional drawing which shows the state when a fluid is discharged from the discharge port of a pump.

Hereinafter, one embodiment of a pump will be described according to the drawings.
As shown in FIGS. 1 and 2, the pump 11 includes a case 12 having a substantially rectangular parallelepiped shape. The case 12 includes a first case 13 as an example of a storage case defining the storage chamber 20, a second case 14 stacked on the first case 13, and a third case stacked on the second case 14. It is divided into fifteen. The first case 13, the second case 14 and the third case 15 are integrally connected by bolts 16 at their four corners.

  In the present embodiment, the second case 14 and the third case 15 have substantially the same thickness, and the first case 13 has a thickness about four times that of the second case 14 or the third case 15. . The second case 14 and the third case 15 constitute a fluid chamber case that defines a fluid chamber 19 having a valve structure therein.

  The third case 15 defines an upper portion of the fluid chamber 19 and is formed to be separated such that a cylindrical inlet 17 through which the fluid is sucked and a cylindrical outlet 18 through which the fluid is discharged form a pair. ing. The second case 14 defines a side of the fluid chamber 19 and is formed with a fluid chamber 19 in communication with both the inlet 17 and the outlet 18 and capable of containing the fluid sucked from the inlet 17. The first case 13 is formed with a storage chamber 20 adjacent to and in fluid communication with the fluid chamber 19.

  The storage chamber 20 is formed substantially throughout the inside of the first case 13. On the bottom surface in the first case 13, a rigid bottom plate 21 is provided so as to cover the entire bottom surface. A cylindrical actuator 22 is fixed to the central portion of the bottom plate 21 by adhesion over the entire surface. The height (axial length) of the actuator 22 is substantially the same as the depth of the storage chamber 20. That is, the actuator 22 is accommodated in the central portion of the accommodation chamber 20. Therefore, a space 23 is formed between the circumferential surface of the actuator 22 and the inner side surface of the first case 13. A hole 24 communicating the inside and the outside of the first case 13 is formed on one side wall of the first case 13. That is, the space 23 is open to the atmosphere through the holes 24.

  As shown in FIG. 2, a surface of the actuator 22 facing the fluid chamber 19 includes a central portion of at least a part of the actuator 22 and a flat fluid chamber forming surface 22 a which forms a part of a wall forming the fluid chamber 19. It is assumed. The fluid chamber forming surface 22 a is formed of a protective layer 25. The protective layer 25 protects the first opposing electrode layer 32, the second opposing electrode layer 33, the dielectric layer 34, and the like described later from the fluid of the fluid chamber 19. The surface of the actuator 22 opposite to the fluid chamber forming surface 22 a is fixed to the bottom surface (inner surface) in the first case 13 via the bottom plate 21.

  The case 12 includes a second case 14 and a third case 15 that constitute a fluid chamber case that defines the fluid chamber 19, a first case 13 that defines a storage chamber case that defines the storage chamber 20, and a second case 14. And an annular seal member 26 which protrudes inward and is fixed. The surface of the seal member 26 on the storage chamber 20 side is an annular seal surface 26 a located at the boundary between the fluid chamber 19 and the storage chamber 20. That is, the sealing surface 26 a is configured by the surface of the sealing member 26 on the storage chamber 20 side.

  A first valve 27 capable of opening and closing the suction port 17 and a second valve 28 capable of opening and closing the exhaust port 18 are disposed between the second case 14 and the third case 15. The first valve 27 and the second valve 28 are configured by an elastic body 29 such as rubber that opens and closes by being elastically deformed by a pressure change of the fluid chamber 19. In the present embodiment, the first valve 27 and the second valve 28 are configured by a single elastic body 29 formed in a substantially rectangular plate shape. That is, one end in the longitudinal direction of the elastic body 29 constitutes the first valve 27, and the other end constitutes the second valve 28.

  The second case 14 is formed with a first recess 30 that allows elastic deformation when the first valve 27 opens. The third case 15 is formed with a second recess 31 which allows elastic deformation when the second valve 28 performs the valve opening operation. Therefore, the first valve 27 is opened by elastically deforming toward the first recess 30 only when the fluid chamber 19 is depressurized, and the second valve 28 is opened only when the fluid chamber 19 is pressurized. The valve is opened by being elastically deformed toward the recess 31 side.

  That is, the first valve 27 is a one-way valve that allows the fluid to enter the fluid chamber 19 from the inlet 17 and prevents the fluid from flowing from the fluid chamber 19 to the inlet 17. The second valve 28 is an exhaust valve. It is a one-way valve that prevents the ingress of fluid from the outlet 18 into the fluid chamber 19 and allows the outflow of fluid from the fluid chamber 19 into the outlet 18.

  As shown in FIG. 3, the actuator 22 is a piezoelectric element made of elastomer, and the first counter electrode layer 32 and the second counter electrode layer 33 constituting the pair of conductive elastomer electrode layers are dielectric layers 34 made of dielectric elastomer. The multi-layered structure is alternately arranged so as to sandwich the central portion of. That is, the first counter electrode layer 32 and the second counter electrode layer 33 are opposed so as to form a pair with the central portion of the dielectric layer 34 interposed therebetween.

  The first opposing electrode layer 32 and the second opposing electrode layer 33 are formed in a thin film shape having a thickness of, for example, 1 to 100 μm. From the peripheral edge of each of the counter electrode layers 32 and 33, linear extension electrodes 32a and 33a connected to the external wires 36 extend to the circumferential surface of the actuator 22.

  Therefore, in the actuator 22, both the first opposing electrode layer 32 and the second opposing electrode layer 33 in the stacking direction are the first region A1 of the peripheral edge where the first opposing electrode layer 32 and the second opposing electrode layer 33 do not overlap, and An overlapping central second area A2 is provided. In this case, the seal member 26 is sealed by pressure contact with the first area A1 of the fluid chamber forming surface 22a. That is, the peripheral portion on the fluid chamber forming surface 22 a side of the actuator 22 cooperates with the sealing surface 26 a to seal between the fluid chamber 19 and the storage chamber 20. In the present embodiment, the protective layer 25 is formed of a material having lower permeability to fluid than the material forming the dielectric layer 34.

  The conductive elastomer (the material of the first opposing electrode layer 32 and the second opposing electrode layer 33) constituting the first opposing electrode layer 32 and the second opposing electrode layer 33 is not particularly limited, and a known elastomer piezoelectric element is used. Conductive elastomers used in the present invention can be used. As said conductive elastomer, the conductive elastomer containing an insulating polymer and a conductive filler is mentioned, for example.

  Examples of the insulating polymer include crosslinked polyrotaxane, silicone elastomer, acrylic elastomer, and urethane elastomer. One of these insulating polymers may be used, or multiple types may be used in combination. Examples of the conductive filler include metal particles such as ketjen black (registered trademark), carbon black, copper and silver. One of these conductive fillers may be used, or a plurality of them may be used in combination.

  The dielectric layer 34 is formed in a thin film shape whose thickness is, for example, 10 to 300 μm. The dielectric elastomer (the material of the dielectric layer 34) constituting the dielectric layer 34 is not particularly limited, and dielectric elastomers used in known elastomeric piezoelectric elements can be used.

  Examples of the dielectric elastomer include crosslinked polyrotaxane, silicone elastomer, acrylic elastomer, and urethane elastomer. One of these dielectric elastomers may be used, or multiple types may be used in combination. The dielectric elastomer (the material of the dielectric layer 34) constituting the dielectric layer 34 of the present embodiment is formed of a crosslinked polyrotaxane.

  An insulating elastomer insulating portion 35 is provided in a region between the dielectric layers 34 adjacent to each other in the stacking direction and in a region where the first counter electrode layer 32 and the second counter electrode layer 33 are not disposed. . The thickness of the insulating portion 35 is the same as the thickness of the first opposing electrode layer 32 and the second opposing electrode layer 33.

  The insulation elastomer (material of the insulation part 35) which comprises the insulation part 35 can use the well-known insulation elastomer used for an insulation part in well-known elastomer piezoelectric elements etc. Examples of the insulating elastomer include cross-linked polyrotaxane, silicone elastomer, acrylic elastomer, and urethane elastomer. One of these insulating elastomers may be used, or multiple types may be used in combination.

  The first opposing electrode layers 32 and the second opposing electrode layers 33 are electrically connected to the power supply 37 via the extension electrodes 32 a and 33 a and the electric wires 36. Therefore, a voltage is applied by the power supply 37 between each first opposing electrode layer 32 and each second opposing electrode layer 33.

Next, the operation of the pump 11 will be described.
As shown in FIGS. 3 and 4, when a voltage is applied to the actuator 22, the surface on the opposite side of the fluid chamber forming surface 22 a in the actuator 22 is fixed to the bottom plate 21, so the actuator 22 is a fluid chamber forming surface It elastically deforms so that the 2nd field A2 in 22a becomes depressed. Then, since the volume of the fluid chamber 19 increases, the fluid chamber 19 is depressurized. Due to the pressure reduction of the fluid chamber 19, the first valve 27 is opened, and the fluid flows into the fluid chamber 19 from the suction port 17.

  At this time, since the first area A1 of the actuator 22 is hardly elastically deformed, the sealing state by the seal member 26 is maintained. Therefore, the fluid in the fluid chamber 19 does not enter the space 23 of the storage chamber 20 from between the seal member 26 and the protective layer 25.

  Subsequently, when the application of the voltage to the actuator 22 is stopped, as shown in FIG. 5, the fluid chamber forming surface 22a of the actuator 22 elastically deformed so as to be recessed is in an original flat state before elastic deformation by elastic restoring force. Return to Then, the fluid in the fluid chamber 19 is pressurized by the actuator 22, and the first valve 27 is closed and the second valve 28 is opened. Thereby, the fluid in the fluid chamber 19 flows to the discharge port 18 and is discharged to the outside.

  Then, the pump 11 repeatedly performs the application of the voltage to the actuator 22 and the stop of the application of the voltage to the actuator 22 described above, thereby suctioning the fluid from the suction port 17 and discharging the fluid from the discharge port 18. Repeat In this case, the actuator 22 only deforms so as to repeat the depression and return to the flat state of the second region A2 in the fluid chamber forming surface 22a which is the surface opposite to the surface fixed to the bottom plate 21. Therefore, even when the viscosity of the fluid is high, the deformation operation is stabilized with high repeatability. Therefore, the pump 11 can stably discharge the fluid in the fluid chamber 19 from the outlet 18 regardless of the viscosity of the fluid.

(Modification example)
The above embodiment may be modified as follows.
The first valve 27 and the second valve 28 do not necessarily have to be constituted by the elastic body 29. That is, the first valve 27 and the second valve 28 may be configured by, for example, a ball valve used in Patent Document 1 or another general one-way valve.

The protective layer 25 may be omitted.
The entire surface of the actuator 22 may be covered with the protective layer 25.
The fluid chamber case may be one in which the second case 14 and the third case 15 are integrated and a flange portion extending outward from the lower edge of the lower case is formed. In this case, by expanding the storage chamber 20 and the actuator 22 to the lower surface of the flange portion, the lower surface of a part of the flange portion can be used as a sealing surface, so the sealing member 26 can be omitted.

  The number of laminated dielectric layers 34 in the actuator 22 and the area of the fluid chamber forming surface 22 a may be changed as appropriate. In this way, it is possible to adjust the suction amount of fluid (suction pressure) from the suction port 17 and the discharge amount of fluid from the discharge port 18 (discharge pressure), so that the pump 11 has a desired specification. Can.

The driving speed and the stroke of the actuator 22 may be controlled by the control unit.
In the above embodiment, the lower surface of the actuator 22 is adhered to the bottom plate 21 and the bottom plate 21 is disposed on the bottom surface in the first case 13. However, the bottom plate 21 is omitted and the lower surface of the actuator 22 is directly on the bottom surface in the first case 13. It may be adhered and fixed to Also, the lower surface of the actuator 22 may be fixed to the bottom surface in the first case 13 using a negative pressure such as a suction cup, for example. In this way, the actuator 22 can be easily fixed to the bottom surface in the first case 13 simply by pressing the lower surface of the actuator 22 against the bottom surface in the first case 13.

  11: Pump, 12: Case, 13: First case constituting the storage case, 14: Second case constituting the fluid chamber case, 15: Third case constituting the fluid chamber case, 17: Suction port, 18 ... Discharge port, 19 ... Fluid chamber, 20 ... Storage chamber, 22 ... Actuator, 22 a ... Fluid chamber formation surface, 25 ... Protective layer, 26 ... Seal member, 26 a ... Seal surface, 27 ... First valve, 28 ... Second Valve 29 elastic body 32 first opposing electrode layer constituting electrode layer 33 second opposing electrode layer constituting electrode layer 34 dielectric layer

Claims (5)

A fluid chamber in communication with both an inlet through which fluid is drawn and an outlet through which the fluid is drained, a fluid chamber capable of receiving the fluid, a receiving chamber adjacent to the fluid chamber, the fluid chamber, and the receiving chamber A case having an annular sealing surface located at the boundary of
An actuator which is accommodated in the accommodating chamber and which has a dielectric layer made of a dielectric elastomer and a pair of electrode layers made of a conductive elastomer opposed to each other across the central portion of the dielectric layer;
A first valve capable of opening and closing the suction port;
A second valve capable of opening and closing the outlet;
Equipped with
The surface facing the fluid chamber in the actuator is a fluid chamber forming surface that includes a central portion of at least a portion of the actuator and forms a portion of a wall surface forming the fluid chamber,
The surface of the actuator opposite to the fluid chamber forming surface is fixed to the inner surface of the case,
A peripheral edge on the fluid chamber forming surface side of the actuator cooperates with the seal surface to seal between the fluid chamber and the storage chamber. The case is
A fluid chamber case defining the fluid chamber;
A storage case defining the storage chamber;
An annular seal member projecting inward and fixed to the fluid chamber case;
Equipped with
The pump according to claim 1, wherein the sealing surface is constituted by a surface of the sealing member on the storage chamber side.   The fluid chamber forming surface is formed of a protective layer formed of a material having a permeability to the fluid lower than that of the material forming the dielectric layer. pump.   The pump according to any one of claims 1 to 3, wherein the dielectric layer is formed of a crosslinked polyrotaxane.   5. The first valve and the second valve according to any one of claims 1 to 4, wherein the first valve and the second valve are made of an elastic body that opens and closes by elastic deformation due to pressure change of the fluid chamber. The pump according to claim 1.