JP2005054658A - Pump device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To securely suck/discharge a compressive fluid such as gases and mixtures. <P>SOLUTION: In this pump device 1, a film-like electrostriction body 3 deformed by the application of voltage thereto is installed in a housing 2 having a suction port 2e and a discharge port 2f for the fluid. Also, in the pump device 1, the electrostriction body 3 is closely fitted to the housing 2 in the state of its outer peripheral part fixed by a fixing ring 5. A suction flow passage (unshown) for the fluid led from the suction port 2e to the fitted face thereof to the electrostriction body 3 and a discharge flow passage (unshown) for the fluid led from the face thereof closely fitted to the electrostriction body 3 to the discharge port 2f are formed in the housing 2. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a pump device that sucks and discharges fluid by the action of pressure, and in particular, a pump device that is suitably used to suck and discharge fluid in a state such as a gas phase or a mixed phase of a gas phase and a liquid phase. It is about.

  In recent years, pumps that suck and discharge fluids by the action of pressure have been miniaturized, and the miniaturized pumps have been incorporated into various devices such as medical equipment, analytical equipment, office equipment, and household equipment. It is used for For example, it can be incorporated into a patient's body to quantitatively administer a particulate or liquid drug to the affected area, or it can be incorporated into an ink jet printer to supply ink from an ink tank to a recording head. Therefore, it is considered that demand and usage in daily life will increase with further miniaturization.

By the way, among the small pumps, there are small pumps using a unimorph type piezoelectric actuator or a bimorph type piezoelectric actuator using a phenomenon that a piezoelectric element is distorted by application of a voltage as a driving source, and have been developed in recent years (for example, see Patent Document 1). In the small pump of Patent Document 1, the upper and lower sides of the pump chamber (2) are covered with the piezoelectric element (3), and the fluid control valve (5) is disposed at the suction port and the discharge port of the pump chamber. By applying an alternating voltage, the piezoelectric element is vibrated to increase or decrease the internal volume of the pump chamber (the internal pressure of the pump chamber fluctuates positively or negatively), and the fluid is sucked through each fluid control valve. The pump is sucked into the pump chamber, and the sucked fluid is discharged from the discharge port of the pump chamber.
Japanese Patent Laid-Open No. 5-263766 (paragraph number 0011, FIG. 1)

  In a pump device in which a pump chamber is disposed in advance, as in the pump device of Patent Document 1, if the fluid is an incompressible fluid such as a liquid in a state where the fluid is sucked and filled in the pump chamber, the displacement of the piezoelectric element Since the pressure of the minute can be transmitted to the fluid as it is, the fluid can be reliably discharged from the pump chamber. However, if the fluid is a compressible fluid such as a gas or a mixture, the pressure of the displacement of the piezoelectric element is If this happens, the fluid may remain in the pump chamber in a compressed state, and only a part of the fluid may be discharged from the pump chamber, or the fluid may not be discharged from the pump chamber at all.

  An object of the present invention is to reliably suck and discharge not only incompressible fluids but also compressible fluids such as gas and air-fuel mixture, and mixed fluids in which incompressible fluids and compressible fluids are mixed. It is to provide a pump device that can.

In order to solve the above-mentioned problem, the invention described in claim 1
In the pump device in which an electrostrictive body that is distorted by application of a voltage is provided in a housing having a fluid suction port and a discharge port, the electrostrictive body, when the housing discharges the fluid from the discharge port, An electrostrictive body is provided in close contact with the housing.

The invention described in claim 2
A housing having a fluid inlet and outlet;
In order to discharge the fluid from the discharge port of the housing, after forming a space with the one surface of the housing, an electrostrictive body closely contacting the housing so as to disappear the space;
It is characterized by having.

The invention according to claim 3
A housing having a fluid inlet and outlet;
An electrostrictive body that is in close contact with the one surface of the housing during non-operation, and is spaced apart from the one surface of the housing during operation;
It is characterized by having.

The invention according to claim 4
In the pump apparatus as described in any one of Claims 1-3,
The electrostrictive body has an outer peripheral portion fixed to the housing,
The housing has a fluid suction channel that leads from the suction port to the contact surface with the electrostrictive body, and a fluid discharge channel that communicates from the contact surface with the electrostrictive body to the discharge port. It is characterized by being.

  The “suction channel” and the “discharge channel” may be formed separately as different channels, or may be formed so that a part of each channel overlaps each other. May be. When the “suction channel” and the “discharge channel” are formed separately from each other, the fluid flows through the suction channel at the time of inhalation and is different from the suction channel at the time of discharge. Flows through the discharge channel. That is, the fluid flows in different flow paths at the time of suction and at the time of discharge. On the other hand, when a part of each flow path overlaps with the “suction flow path” and the “discharge flow path”, the fluid is the overlapping part of the suction flow path and the suction / discharge flow path during suction. And the flow path in the overlapping portion of the discharge flow path and the suction / discharge flow path at the time of discharge. That is, the fluid flows through each flow path while passing through the same part during suction and during discharge.

The invention described in claim 5
The pump device according to claim 4,
The housing is equipped with a plurality of the electrostrictive bodies,
Each of the plurality of electrostrictive bodies has an outer peripheral portion fixed to the housing,
The suction channel communicates from the suction port to each of the contact surfaces of all the electrostrictive bodies and the housing;
The discharge flow path is characterized in that all the electrostrictive bodies and the housing are connected to the discharge port from the respective contact surfaces.

The invention described in claim 6
The pump device according to any one of claims 1 to 5, wherein the electrostrictive body is a dielectric polymer film having thin film electrodes formed on both sides.

The invention described in claim 7
The pump device according to claim 6,
The dielectric polymer film is made of a silicon elastomer, an acrylic elastomer, or a polyurethane elastomer.

The invention according to claim 8 provides:
In the pump device according to any one of claims 1 to 7,
The pump device according to claim 1, wherein a first check valve that allows fluid inflow and blocks fluid outflow is disposed in the suction port.

The invention according to claim 9 is:
The pump device according to claim 8,
The first check valve is a duckbill valve whose tip is directed from the outside to the inside of the suction port.

The invention according to claim 10 is:
In the pump device according to any one of claims 1 to 9,
The discharge port is provided with a second check valve that allows the fluid to flow out and blocks the fluid from flowing in.

The invention according to claim 11
The pump device according to claim 10,
The second check valve is a duckbill valve whose tip is directed from the inside of the discharge port to the outside.

  According to the first aspect of the present invention, when the fluid sucked from the suction port is discharged from the discharge port due to the distortion of the electrostrictive body, the electrostrictive body is formed in close contact with the housing and formed between the electrostrictive body and the housing. Therefore, the fluid hardly disappears in the compressed state, and the fluid can be effectively transferred.

  In the invention according to claim 2, the electrostrictive body uses the negative pressure in the space formed between the electrostrictive body and the housing due to the distortion of the electrostrictive body to absorb the fluid sucked into the space. When crushing and discharging from the discharge port of the housing, the electrostrictive body comes into close contact with the housing, so that the space is almost lost. Therefore, the fluid hardly remains in a compressed state in the space, and the fluid can be transferred effectively.

  In the third aspect of the invention, since the electrostrictive body is in close contact with one surface of the housing during non-operation, the electrostrictive body is formed between the electrostrictive body and the housing when separated from the one surface of the housing during operation. It is possible to easily make negative pressure in the space. Therefore, even if the fluid is compressible, it can be efficiently sucked into the space from the suction port. When the electrostrictive body crushes the space and discharges the fluid from the discharge port of the housing, the electrostrictive body is in close contact with the housing and the space is almost lost, so that the fluid remains compressed in the space. There is almost nothing and the fluid can be transferred effectively.

  In the invention according to claim 4, since the electrostrictive body is in close contact with the housing in a state where the outer peripheral portion is fixed, the electrostrictive body can be distorted in a dome shape while the outer peripheral portion is fixed. A space is formed on the contact surface between the strain body and the housing. At this time, since negative pressure (suction force) is generated in the space, the suction force is transmitted to the suction port through the suction channel, and the fluid is sucked from the suction port and flows through the suction channel. And is temporarily stored in the space. When the application of the voltage to the electrostrictive body is released from this state, the electrostrictive body comes into close contact with the housing so as to gradually disappear the space once formed. At this time, since the space formed between the electrostrictive body and the housing disappears while shrinking, a positive pressure (pressing force) is applied to the fluid as the electrostrictive body approaches the housing, The liquid flows out from the space to the discharge channel and is discharged from the discharge port while flowing through the discharge channel.

  In the invention according to claim 5, since a plurality of electrostrictive bodies are provided in the housing, a plurality of spaces are formed simultaneously between the electrostrictive bodies and the housing, and the respective spaces are simultaneously contracted to disappear. be able to.

  In the invention described in claim 6, since the electrostrictive body is a dielectric polymer film in which thin film electrodes are formed on both surfaces, a dielectric polymer is provided by applying a potential difference between the thin film electrodes of the electrostrictive body. The film can be distorted, and conversely, the dielectric polymer film can be returned to the original state (the state before distortion) by releasing the potential difference between the thin film electrodes of the electrostrictive body.

  In the seventh aspect of the invention, since the dielectric polymer film is made of silicon elastomer, acrylic elastomer, or polyurethane elastomer, the distortion rate of the electrostrictive body is very large. Therefore, a large-capacity space can be formed on the contact surface between the electrostrictive body and the housing, and the amount of fluid sucked and discharged can be increased.

  In the invention according to claim 8, since the first check valve is disposed at the suction port, the fluid can be allowed to flow from the suction port only when the fluid is sucked, and the fluid is sucked when the fluid is discharged. Can be prevented from flowing out (leaking) out of the suction port.

  In the invention described in claim 9, since the first check valve is a duckbill valve whose tip is directed from the outside to the inside of the suction port, the first check valve is substantially in the direction in which the fluid flows when allowing the inflow of fluid. Open in the vertical direction. Therefore, the resistance of the fluid acting on the first check valve can be kept low, and chattering can be prevented from occurring in the first check valve.

  In the invention according to claim 10, since the second check valve is disposed at the discharge port, the fluid can flow out from the discharge port only at the time of discharging the fluid, and the fluid is discharged from the discharge port at the time of inhaling the fluid. Can be prevented from flowing back into the discharge port.

  In the invention according to claim 11, since the second check valve is a duckbill valve whose tip is directed from the inside of the discharge port to the outside, the second check valve is substantially in the direction in which the fluid flows when allowing the fluid to flow out. Open in the vertical direction. Therefore, the resistance of the fluid acting on the second check valve can be kept low, and chattering can be prevented from occurring in the second check valve.

Hereinafter, embodiments of a pump device according to the present invention will be described with reference to the drawings. However, the scope of the invention is not limited to the illustrated examples.
1 is a perspective view of the pump device 1, FIG. 2 is an exploded perspective view of the pump device 1, FIG. 3 is a perspective view showing an AA cross section of the pump device 1 of FIG. 1, and FIG. It is a perspective view which shows the BB cross section of 1 pump apparatus.

  As shown in FIG.1 and FIG.2, the pump apparatus 1 has the housing 2 which exhibited the external appearance which integrated the circular member and the tubular member in the outer peripheral part of the circular member. As shown in FIG. 2, the housing 2 has a disc portion 2a having a predetermined thickness, and a first through hole 2b is formed at a substantially central portion of the disc portion 2a. A wall 2c along the outer edge of the disc portion 2a is formed on the outer peripheral portion.

  On the outer peripheral portion of the disc portion 2a, a protruding portion 2d that protrudes in a square shape from the outer edge of the disc portion 2a is disposed. A suction port 2e for sucking fluid and a discharge port 2f for discharging fluid are disposed on the left and right sides (or both front and rear sides) of the protrusion 2d. The suction port 2e and the discharge port 2f are similar to each other, and both the outer diameter and the inner diameter are the same. The term “fluid” as used herein refers to all of liquid, gas, a mixture of liquid and gas, particles, etc., which freely deform or flow with respect to external force such as pressure. In the pump device 1 of the present embodiment, a compressive fluid such as a gas or an air-fuel mixture can be suitably used as the fluid.

  As shown in FIGS. 3 and 4, a second through hole 2 g that communicates from the suction port 2 e to the discharge port 2 f (or from the discharge port 2 f to the suction port 2 e) is formed inside the protruding portion 2 d of the housing 2. Yes. As shown in FIG. 3, a third through hole 2 h that communicates with the second through hole 2 g and the first through hole 2 b is also formed inside the disc portion 2 a of the housing 2. The third through hole 2h is connected to the first and second through holes 2b and 2g while intersecting in a T shape. As shown in FIG. 3, the side of the projecting portion 2d has a hole 2i opened when the third through-hole 2h is formed (which leads to the third through-hole 2h through the second through-hole 2g). Is formed). An elastic pin 2j is press-fitted into the hole 2i, and the hole 2i is completely closed by the pin 2j.

  In FIG. 2, electrostrictive bodies 3 and 4 are respectively disposed above and below the disc portion 2a. Each electrostrictive body 3, 4 is an actuator device called EAPAD (Electroactive Polymer Actuators and Device) or the like, and a so-called “dielectric polymer” called a dielectric elastomer, electrostrictive polymer or the like is formed into a film. And is sandwiched between two flexible thin film electrodes. The polymer film of each electrostrictive body 3 and 4 is made of a polymer material such as silicon (including soft silicon and fluorosilicone) type elastomer, acrylic type elastomer, polyurethane type elastomer, and the like. It is produced by a known technique such as a coating method, a casting method, or a spray method. The thin film electrodes of the electrostrictive bodies 3 and 4 are also produced by the same technique as the polymer film. When the thin film electrodes of the electrostrictive bodies 3 and 4 are made of a material such as gold (Au), It can also be produced by photolithography.

  The electrodes of the electrostrictive bodies 3 and 4 are connected to a drive circuit (not shown) via lead wires (not shown), and a voltage is applied between the thin film electrodes by the drive circuit. When a voltage is applied between the thin film electrodes and a predetermined potential difference is applied between the thin film electrodes, the electrostrictive bodies 3 and 4 are distorted so as to expand or contract the area. In the pump device 1, one electrostrictive body 3 is superimposed on the upper part of the disk portion 2 a so as to fit inside the wall 2 c, as shown in FIGS. 1 and 3, and the other electrostrictive body 4. As shown in FIG. 3, it is arrange | positioned so that it may fit in the lower part of the disc part 2a located inside the wall 2c.

  In FIG. 2, fixing rings 5 and 6 having substantially the same diameter as the diameter of the disk portion 2a of the housing 2 (inner diameter of the wall 2c) are arranged above the electrostrictive body 3 and below the electrostrictive body 4, respectively. It is installed. In the pump device 1, the fixing ring 5 has a wall so as to fix the outer peripheral portion of the electrostrictive body 3 in a state where the electrostrictive body 3 is overlaid on the upper part of the disk portion 2 a as shown in FIGS. 1 and 3. Bonded and fixed inside 2c. Similarly, as shown in FIG. 3, the fixing ring 6 is provided on the inner side of the wall 2c so as to fix the outer peripheral portion of the electrostrictive body 4 in a state where the electrostrictive body 4 is disposed below the disc portion 2a. Bonded and fixed. In such a state, each of the electrostrictive bodies 3 and 4 is in close contact with the upper portion (upper surface) and the lower portion (lower surface) of the disk portion 2a of the housing 2.

  In FIG. 2, a metal sleeve (sheath tube) 7 is provided in front of the suction port 2e of the housing 2 and a first reverse at least partly deformed by pressure applied when inserted into the sleeve 7. A stop valve 8 is provided. The outer diameter of the sleeve 7 is substantially the same as the inner diameter of the suction port 2 e, and the inner diameter of the sleeve 7 is slightly smaller than the outer diameter of the first check valve 8. In the pump device 1, first, the sleeve 7 is fitted and fixed inside the suction port 2e, and then the first check valve 8 is press-fitted and fixed inside the sleeve 7 (see FIG. 4). ).

  In FIG. 2, a second check valve 9 similar to the first check valve 8 and a sleeve 10 similar to the sleeve 7 are disposed in front of the discharge port 2 f of the housing 2. . The outer diameter of the sleeve 10 is substantially the same as the inner diameter of the discharge port 2 f, and the inner diameter of the sleeve 10 is slightly smaller than the outer diameter of the second check valve 9. In the pump device 1, the second check valve 9 is first fitted and arranged inside the discharge port 2 f, and then the sleeve 10 is press-fitted between the side wall of the first check valve 9 and the inner wall of the discharge port 2 f. -It is designed to be fixed (see Fig. 4).

Next, the check valves 8 and 9 will be described in detail with reference to FIG.
FIG. 5 is a three-side view of the check valves 8 and 9 viewed from three directions. FIG. 5A is a side view of the check valves 8 and 9, and FIG. FIG. 5C is a front view of the valves 8 and 9, and FIG. 5C is a plan view of the check valves 8 and 9.

  The first check valve 8 is a duckbill valve having a duckbill-like appearance (shaped like a duck or duck beak). Specifically, as shown in FIG. 5A, the outer surface 8a of the first check valve 8 is formed in a tapered shape so that the thickness T gradually decreases toward the tip end portion 8c. An opening 8e is formed on the inner side of the first check valve 8, and the inner surface 8b of the opening 8e is gradually increased in height H toward the tip 8c in the same manner as the outer surface 8a. It is formed in a tapered shape so as to be lowered. As shown in FIG. 5 (b), a linear outflow port 8 d is formed at the tip 8 c of the first check valve 8 in a direction perpendicular to the thickness direction of the first check valve 8. Yes. The outflow port 8d communicates from the outside of the first check valve 8 to the opening 8e (from the opening 8e to the outside).

  In the first check valve 8, when the pressure applied to the outer surface 8 a and the inner surface 8 b of the first check valve 8 is equal or the pressure applied to the outer surface 8 a of the first check valve 8 is greater than that of the inner surface 8 b. The outlet 8d is closed to prevent the fluid from flowing from the outside of the first check valve 8 to the opening 8e. On the other hand, when a larger pressure is applied to the inner surface 8b of the first check valve 8 than the outer surface 8a, the first check valve 8 is elastically deformed and the thickness T of the tip 8c is increased, thereby increasing the outlet 8d. And the fluid is allowed to flow from the opening 8e to the outside of the first check valve 8 through the outlet 8d.

  The second check valve 9 is the same as the first check valve 8 and is a duckbill valve having a duckbill-like appearance. In the second check valve 9, the outer surface 9a corresponds to the outer surface 8a of the first check valve 8, the inner surface 9b corresponds to the inner surface 8b of the first check valve 8, and the first check valve 8 A tip portion 9 c corresponds to the tip portion 8 c of the check valve 8, an outlet port 9 d corresponds to the outlet port 8 d of the first check valve 8, and the opening portion 8 e of the first check valve 8. The detailed description of the second check valve 9 will be omitted.

  In each of the check valves 8 and 9 configured as described above, in the pump device 1, as shown in FIG. 4, the first check valve 8 sucks in a state where the tip end portion 8 c faces the second through hole 2 g. The second check valve 9 is disposed inside the discharge port 2f with the tip 9c facing the outside of the discharge port 2f.

Next, the operation of the pump device 1 will be described with reference mainly to FIG.
6 (a), 6 (b), and 6 (d) are cross-sectional views taken along line AA of the pump device 1 of FIG. 1 for illustrating the operation of the pump device 1 over time, and FIGS. e) is a BB cross-sectional view of the pump device 1 of FIG. 1 for explaining the operation of the pump device 1 over time.

  In a state before the operation of the pump device 1 (a state before the drive circuit is activated), the entire surface of the two electrostrictive bodies 3 and 4 of the disk portion 2a of the housing 2 is formed as shown in FIG. It is in close contact with the top and bottom. Further, the outlets 8d and 9d of the two first and second check valves 8 and 9 are closed. When the drive circuit operates in this state, a voltage is applied between the thin film electrodes of the two electrostrictive bodies 3 and 4 to generate a potential difference. First, the electrostrictive bodies 3 and 4 are simultaneously distorted so as to increase the area.

  At this time, as shown in FIG. 6B, the outer peripheral portion of the electrostrictive body 3 disposed on the upper portion of the disk portion 2a of the housing 2 which becomes a steric hindrance to the distortion operation of the electrostrictive bodies 3 and 4 Since it is fixed by the fixing ring 5, the electrostrictive body 4 is bent so as to bend upward (actually distorted upward in a dome shape), and the electrostrictive body 4 disposed at the lower part of the disk portion 2 a of the housing 2 is Since the outer peripheral portion is fixed by the fixing ring 6, it bends so as to bend downward (actually, it is distorted in a dome shape downward). Then, space portions 11 and 12 are formed between the electrostrictive bodies 3 and 4 and the disc portion 2a, respectively, and negative pressure (suction force) is generated in each space portion 11 and 12, and the suction force is It is transmitted to the suction port 2e and the discharge port 2f via the first through hole 2b, the third through hole 2h, and the second through hole 2g.

  Therefore, as shown in FIG. 6C, at the suction port 2e, the pressure of the suction force generated in each of the space portions 11 and 12 is applied to the outer surface 8a of the first check valve 8, and the pressure applied to the outer surface 8a is increased. Since the pressure is smaller than the pressure applied to the inner surface 8b, the first check valve 8 is elastically deformed to open the outlet 8d. On the other hand, at the discharge port 2f, the suction force generated in each of the space portions 11 and 12 is applied to the inner surface 9b via the opening 9e of the second check valve 9, and the pressure applied to the inner surface 9b is greater than the pressure applied to the outer surface 9a. Therefore, the outlet 9d of the second check valve 9 is kept closed.

  In this state, the fluid disposed outside the pump device 1 is sucked from the suction port 2 e of the housing 2. The second through-hole 2g, the third through-hole 2h, and the first through-hole 2b serve as a “suction channel” for the fluid, and the fluid passes through the opening 8e of the first check valve 8 and It flows into the 2nd through-hole 2g via the outflow port 8d, and flows into each space part 11 and 12, flowing through the 2nd through-hole 2g, the 3rd through-hole 2h, and the 1st through-hole 2b in this order. To do.

  Thereafter, the drive circuit is operated again, and the application of the voltage applied between the thin film electrodes of the two electrostrictive bodies 3 and 4 is canceled or the electric field reverse to the state of FIG. When a voltage is applied between the thin film electrodes of the two electrostrictive bodies 3 and 4, the electrostrictive bodies 3 and 4 simultaneously disappear the space portions 11 and 12, as shown in FIG. Then, the original state (the state shown in FIG. 6A) is restored (to repair the distortion generated in the thickness direction and the surface direction). At this time, each of the electrostrictive bodies 3 and 4 has an upper portion of the disk portion 2a of the housing 2 while applying positive pressure (pressing force) to the fluid flowing into the space portions 11 and 12 (see FIG. 6B). Close contact with the bottom.

  The first through-hole 2b, the third through-hole 2h, and the second through-hole 2g serve as a “discharge channel” for the fluid, and the fluid that has received the pressing force is used for suction when sucked. It flows out from each space part 11 and 12 to the 1st through-hole 2b so that it may flow back in a flow path, and it flows through the 1st through-hole 2b, the 3rd through-hole 2h, and the 2nd through-hole 2g in this order. It flows out to the suction port 2e and the discharge port 2f. In the present embodiment, among the three through holes 2b, 2g, 2h constituting the fluid suction channel and the discharge channel, in particular, the first through hole 2b and the third through hole 2h are each sucked. -Since these are overlapping portions in the discharge flow path, these occupied volumes can be kept small. That is, when the operation for extruding the fluid shown in FIG. 6D is completed, the volume in which the fluid stays is extremely small.

  In such a state, as shown in FIG. 6E, at the suction port 2e, the pressure of the fluid that has flowed in is applied to the outer surface 8a of the first check valve 8, and the pressure applied to the outer surface 8a is applied to the inner surface 8b. Since it becomes larger than the pressure, the outlet 8d is closed. This prevents the fluid from flowing and prevents the fluid from flowing out from the suction port 2e. On the other hand, in the discharge port 2f, the pressure of the fluid that has flowed in is applied to the inner surface 9b via the opening 9e of the second check valve 9, and the pressure applied to the inner surface 9b is greater than the pressure applied to the outer surface 9a. The second check valve 9 is elastically deformed to open the outlet 9d. Thus, the fluid is discharged from the opening 9e of the second check valve 9 through the outlet 9d to the outside of the pump device 1 through the discharge port 2f.

  Thereafter, the pump device 1 repeats the above-described series of voltage control operations on the electrostrictive bodies 3 and 4 simultaneously, thereby sucking fluid from the suction port 2e and discharging it from the discharge port 2f as described above. A series of operations shown in FIGS. 6B to 6E are repeated.

  In the pump device 1 as described above, by applying a voltage to the electrostrictive bodies 3 and 4, the space portions 11 and 12 are formed between the electrostrictive bodies 3 and 4 and the disk portion 2 a of the housing 2. The fluid can be sucked from the suction port 2e, and by changing the voltage application state to the electrostrictive bodies 3 and 4 from this state, the space portions 11 and 12 are contracted and disappeared to discharge the fluid. It is possible to discharge from 2f. Therefore, even if the two space portions 11 and 12 are formed between the electrostrictive bodies 3 and 4 and the housing, the spaces 11 and 12 disappear while contracting, so the fluid shown in FIG. When the operation for pushing out is completed, unlike the conventional pump device in which the pump chamber is previously arranged, the fluid sucked from the suction port 2e is compressed and remains in a predetermined portion (a space like the pump chamber). Therefore, the amount of fluid sucked from the suction port 2e can be reliably discharged from the discharge port 2f. Thereby, in the pump apparatus 1, compressive fluids, such as gas and air-fuel | gaseous mixture, can be suck | inhaled and discharged reliably.

  Here, as shown in FIG. 6B, the first through-hole 2 b has the electrostrictive bodies 3, 4 of the disk portion 2 a of the housing 2 when the space portions 11, 12 are formed. It is provided at a position facing the portion farthest from the contact surface (that is, the central portion of the contact surface of the electrostrictive bodies 3 and 4). That is, as shown in FIG. 6 (d), the first electrostrictive bodies 3, 4 in the distorted state are located at positions where they are most physically displaced when they are brought into close contact with the close contact surface of the disk portion 2 a of the housing 2. Since the through holes 2b are arranged, the electrostrictive bodies 3 and 4 have a large force for pushing the fluid in the space portions 11 and 12 into the first through holes 2b, and the fluid in the space portions 11 and 12 is large. Can be efficiently transported.

  Further, in the pump device 1, since the “dielectric polymer film” constituting each electrostrictive body 3, 4 is made of silicon elastomer, acrylic elastomer, or polyurethane elastomer, one side of the diaphragm (shim material) Alternatively, the electrostrictive bodies 3 and 4 have a very large distortion rate as compared to “unimorph actuators” or “bimorph actuators” in which piezoelectric elements (piezoelectric ceramics) are attached to both surfaces. Therefore, large-capacity space portions 11 and 12 can be formed on the contact surfaces between the electrostrictive bodies 3 and 4 and the disk portion 2a of the housing 2, respectively, and the amount of fluid sucked and discharged can be increased. it can.

  Further, in the pump device 1, the first check valve 8 and the second check valve 9 are both duckbill valves, and the tip portions 8 c of the first check valve 8 and the second check valve 9 are each. 9c are directed in the direction in which the fluid flows, and are opened in a direction substantially perpendicular to the direction in which the fluid flows when fluid inflow / outflow is permitted. Therefore, the resistance of the fluid acting on the first check valve 8 and the second check valve 9 can be kept low, and chattering occurs in the first check valve 8 and the second check valve 9. Can be prevented. Since the first check valve 8 and the second check valve 9 are both duckbill valves and the resistance of the fluid acting on the check valves 8 and 9 can be kept low, the first check valve 8 And the opening / closing operation | movement of the 2nd non-return valve 9 can be made to follow the space formation operation | movement of each electrostrictive body 3 and 4 and space vanishing operation | movement substantially simultaneously. Accordingly, the electrostrictive bodies 3 and 4 can be driven with a short cycle, and as a result, the pump device 1 can be driven at a high speed.

  The present invention is not limited to the above-described embodiment, and various improvements and design changes may be made without departing from the spirit of the present invention.

  For example, in the present embodiment, the first through hole 2b is disposed at the center of the disc portion 2a of the housing 2, but the first through hole 2b is disposed at the center as in the pump device 101 shown in FIG. It may be arranged closer to the second through hole 2g. By adopting such a structure, the length of the third through-hole 2h is shortened, so that the volume of the third through-hole 2h is further reduced, and the dead space where the compressible fluid is retained can be further reduced. It is possible to reduce the adverse effects of fluid suction and discharge.

  In the present embodiment, the two electrostrictive bodies 3 and 4 are arranged one by one on the upper and lower parts of the disk portion 2a of the housing 2, but the number of electrostrictive bodies 3 and 4 is limited to this. Instead, only one of the two electrostrictive bodies 3 and 4 may be mounted on the housing 2. Conversely, for example, a plurality of electrostrictive bodies similar to the electrostrictive bodies 3 and 4 are arranged side by side on the upper or lower portion of the disk portion 2a, or the disk portion 2a is formed into a polygonal body such as a trihedron or a tetrahedron. Instead, one or a plurality of electrostrictive bodies similar to the electrostrictive bodies 3 and 4 are arranged on each surface, and three or more electrostrictive bodies similar to the electrostrictive bodies 3 and 4 are arranged on the outer periphery. You may arrange | position to the housing 2 in the state which fixed the part.

  Further, in the present embodiment, among the three through holes 2b, 2g, 2h, the first through hole 2b and the third through hole 2h serve as overlapping portions of the suction / discharge channels, and the three through holes 2b, The suction / discharge channels are formed from 2g and 2h, but the suction channels from the suction port 2e to the electrostrictive bodies 3 and 4 and the discharge channels from the electrostrictive bodies 3 and 4 to the discharge port 2f. Through holes (including three through holes 2b, 2g, and 2h) may be formed in the housing 2 so that the flow paths exist independently as separate flow paths. Of course, when three or more electrostrictive bodies similar to the electrostrictive bodies 3 and 4 are disposed in the housing 2 as described above, the suction flow paths leading from the suction port 2e to the electrostrictive bodies and the electrostrictive bodies are provided. A through-hole may be formed in the housing 2 so that the discharge flow paths leading from the body to the discharge port 2f are different from each other as separate flow paths, or the suction flow path and the discharge flow path A through hole may be formed in the housing 2 so that a part of each flow path overlaps.

  Furthermore, in this embodiment, the outer peripheral part of each electrostrictive body 3 and 4 is fixed with the two fixing rings 5 and 6, and the first through hole 2b of the housing 2 is closed with the two electrostrictive bodies 3 and 4. However, it is sufficient that at least the portion surrounding the first through hole 2b of each electrostrictive body 3, 4 is fixed without fixing the outer peripheral portion of each electrostrictive body 3, 4. Of course, as described above, when only one of the two electrostrictive bodies 3 and 4 is disposed in the housing 2, three or more electrostrictive bodies similar to the electrostrictive bodies 3 and 4 are provided in the housing 2. Even in the case of disposing, it is sufficient that at least the portion surrounding the end portion of the through hole as the suction / discharge flow path of each electrostrictive body is fixed. However, fixing the outer peripheral portion of each electrostrictive body (including electrostrictive bodies 3 and 4) has a larger space between each electrostrictive body and the housing 2 when each electrostrictive body is distorted. Each of the electrostrictive bodies (including the space portions 11 and 12) can be formed. It is more advantageous to fix the outer periphery of the electrostrictive body.

  Furthermore, in this embodiment, “dielectric polymer” in which thin film electrodes are formed on both surfaces is applied as each electrostrictive body 3, 4. However, the above “unimorph” is used as an actuator (device) in place of electrostrictive bodies 3, 4. Actuators such as “type piezoelectric actuator” and “bimorph type piezoelectric actuator” may be applied. However, unimorph actuators and bimorph actuators have a very small amount of displacement of the diaphragm, so the pressure that generates fluid suction / discharge force is very weak. Not suitable for handling.

  Further, in the present embodiment, the first check valve 8 and the second check valve 9 are both duckbill valves, but either the first check valve 8 or the second check valve 9 is used. May be duckbill valves, or both may not be duckbill valves. Examples of the check valve other than the duckbill valve include a spring type check valve, a lift type check valve, a swing type check valve, a diaphragm type check valve, and the like. From the viewpoint, it is preferable that the first check valve 8 and the second check valve 9 are both duckbill valves made of the same shape and material.

  By the way, the pump device 1 as described above can be incorporated into a fuel reforming type fuel cell power generation device, an ink jet printer, a medical device, an analysis device, and other devices / devices having a pump mechanism.

  For example, the pump device 1 can be incorporated in a fuel reforming type fuel cell power generator 30 as shown in FIG. However, FIG. 8 shows a partially broken perspective view of the power generator 30. As shown in FIG. 8, the power generation device 30 generates power using a fuel storage module 32 that stores a liquid fuel 31 obtained by mixing chemical fuel (alcohols and the like) and water, and the fuel 31 stored in the fuel storage module 32. And a power generation module 33.

  The fuel storage module 32 stores a fuel tank 34 that actually stores the fuel 31. The power generation module 33 includes a vaporizer 35, a reformer 36, a carbon monoxide remover 37, and a fuel cell 38. It is installed. In the power generation module 33, a supply pipe 39 is provided between the supply port 41 of the fuel tank 34 and the vaporizer 35, and a pump device 42 is provided in the middle of the supply pipe 39. The pump device 42 sucks and discharges an incompressible fluid such as a liquid, and may have the same structure as the pump device 1 described above, or may have a different structure. In the power generation module 33, a supply pipe 43 is also arranged between the carbon monoxide remover 37 and the fuel cell 38, and the pump device 1 according to the present invention is arranged in the middle of the supply pipe 43. . The vaporizer 35, the reformer 36, and the carbon monoxide remover 37 are each formed with a flow path through which the fluid moves. One end of the flow path of the reformer 36 is the flow path of the vaporizer 35. One end communicates with the other end, and the other end communicates with one end of the flow path of the carbon monoxide remover 37.

  When each pump device 1, 42 operates in such a power generation device 30, the fuel 31 in the fuel tank 34 is sucked into the pump device 42 through the supply pipe 40 and the supply pipe 39 disposed inside the fuel tank 32. Then, the gas is discharged from the pump device 42 to the vaporizer 35. The fuel 31 changed from the liquid phase to the gas phase in the vaporizer 35 significantly increases its volume, increases the pressure in the flow path of the vaporizer 35, and moves toward the reformer 36 under a lower pressure. At this time, the pump device 1 forcibly supplies the fluid to the supply pipe 43 so that each flow path in the reformer 36 and the carbon monoxide remover 37 is negatively pressured, and the fluid is quickly supplied to the vaporizer 35. The flow paths of the reformer 36 and the carbon monoxide remover 37 may be moved.

  The fuel 31 discharged in a vaporized state in the flow path of the vaporizer 35 is transferred into the flow path of the reformer 36. Specifically, in the flow path of the reformer 36, the fuel 31 vaporized by the vaporizer 35 is reformed into hydrogen gas, and the hydrogen gas contains carbon dioxide and a small amount of carbon monoxide as by-products. The reformed gas in a state is sent to the carbon monoxide remover 37. In the flow path of the carbon monoxide remover 3, carbon monoxide gas in the reformed gas is removed, and hydrogen gas in the reformed gas is selectively sucked into the pump device 1 and supplied from the pump device 1 to the supply pipe 43. To the fuel cell 38. Finally, in the fuel cell 38, the hydrogen supplied from the pump device 1 is used to cause an electrochemical reaction to generate electric energy.

  Since the pump device 1 according to the present invention can be suitably used when handling a compressible gas as a fluid, the power generation device 30 shown in FIG. 8 is a pump that sucks and discharges hydrogen gas in the reformed gas. Although the pump device 1 is applied as the device, the pump device 1 may be applied instead of the pump device 42 that sucks and discharges the incompressible fuel 31. Further, in the power generation device 30 shown in FIG. 8, the pump device 1 is interposed between the vaporizer 35 and the reformer 36 or between the reformer 36 and the carbon monoxide remover 37, and the pump device 1. May be used to supply the gas-phase fuel 31 from the vaporizer 35 to the reformer 36, or to supply the reformed gas from the reformer 36 to the carbon monoxide remover 37. Good.

  According to the pump device 1, by applying a voltage to the electrostrictive bodies 3, 4, the space portions 11, 12 can be formed between the electrostrictive bodies 3, 4 and the housing 2, and fluid can be sucked. By canceling the application of the voltage to the electrostrictive bodies 3 and 4 from this state, the space portions 11 and 12 can be contracted and disappeared to discharge the fluid. Thus, in the pump device 1, even if the space portions 11, 12 are formed between the electrostrictive bodies 3, 4 and the housing 2, the space portions 11, 12 disappear while contracting. Between the electrostrictive bodies 3 and 4 and the housing 2 when the fluid discharge operation 4 is performed, the volume of the space in which the fluid can remain in a compressed state is extremely small. Therefore, the fluid sucked from the suction port 2e can be reliably discharged from the discharge port 2f. Therefore, a compressive fluid such as a gas or an air-fuel mixture can be reliably sucked and discharged.

It is a perspective view of a pump apparatus. It is a disassembled perspective view of a pump apparatus. It is a perspective view which shows the AA cross section of the pump apparatus of FIG. It is a perspective view which shows the BB cross section of the pump apparatus of FIG. It is the three-plane figure which looked at the check valve from three directions, (a) Side view of check valve (b) Front view of check valve (c) Plan view of check valve. It is drawing for demonstrating operation | movement of a pump apparatus with time, (a) It is AA sectional drawing of the pump apparatus of FIG. 1 which shows the state before operation | movement of a pump apparatus, (b) Each electrostrictive body is It is AA sectional drawing of the pump apparatus of FIG. 1 which shows the distorted state, (c) It is BB sectional drawing of the pump apparatus of FIG. 1 which shows the state in which the fluid is suck | inhaled from an inlet port, (d). It is AA sectional drawing of the pump apparatus of FIG. 1 which shows the state from which distortion of each electrostrictive body was cancelled | released, (E) BB of the pump apparatus of FIG. 1 which shows the state from which a fluid is discharged from a discharge port It is sectional drawing. It is drawing which shows the other example of a pump apparatus. It is a partially broken perspective view which shows the electric power generating apparatus incorporating the pump apparatus which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pump apparatus 2 Housing 2a Disk part 2b 1st through-hole 2c Wall 2d Projection part 2e Suction port 2f Discharge port 2g 2nd through-hole 2h 3rd through-hole 2i hole 2j Pin 3, 4 Electrostrictive body 5, 6 fixing ring 7 sleeve 8 first check valve 9 second check valve 8a, 9a outer surface 8b, 9b inner surface 8c, 9c tip 8d, 9d outlet 8e, 9e opening 10 sleeve 11, 12 space DESCRIPTION OF SYMBOLS 30 Power generator 31 Fuel 32 Fuel storage module 33 Power generation module 34 Fuel tank 35 Vaporizer 36 Reformer 37 Carbon monoxide remover 38 Fuel cell 39, 40, 43 Supply pipe 41 Supply port 42 Pump apparatus

Claims (11)

In the pump device in which the electrostrictive body distorted by the application of the voltage is equipped in the housing having the fluid inlet and outlet,
The pump device, wherein the electrostrictive body is provided so that the electrostrictive body is in close contact with the housing when the housing discharges the fluid from the discharge port. A housing having a fluid inlet and outlet;
In order to discharge the fluid from the discharge port of the housing, after forming a space with the one surface of the housing, an electrostrictive body closely contacting the housing so as to disappear the space;
A pump apparatus comprising: A housing having a fluid inlet and outlet;
An electrostrictive body that is in close contact with the one surface of the housing during non-operation, and is spaced apart from the one surface of the housing during operation;
A pump apparatus comprising: In the pump apparatus as described in any one of Claims 1-3,
The electrostrictive body has an outer peripheral portion fixed to the housing,
The housing has a fluid suction channel that leads from the suction port to the contact surface with the electrostrictive body, and a fluid discharge channel that communicates from the contact surface with the electrostrictive body to the discharge port. The pump apparatus characterized by being made. The pump device according to claim 4,
The housing is equipped with a plurality of the electrostrictive bodies,
Each of the plurality of electrostrictive bodies has an outer peripheral portion fixed to the housing,
The suction channel communicates from the suction port to each of the contact surfaces of all the electrostrictive bodies and the housing;
The pump device, wherein the discharge flow path leads to the discharge port from each contact surface between all the electrostrictive bodies and the housing. In the pump device according to any one of claims 1 to 5,
The pump device, wherein the electrostrictive body is a dielectric polymer film having thin film electrodes formed on both sides. The pump device according to claim 6,
2. The pump device according to claim 1, wherein the dielectric polymer film is made of a silicon elastomer, an acrylic elastomer, or a polyurethane elastomer. In the pump device according to any one of claims 1 to 7,
The pump device according to claim 1, wherein a first check valve is provided at the suction port to allow inflow of fluid and to block outflow of fluid. The pump device according to claim 8,
The pump device according to claim 1, wherein the first check valve is a duckbill valve whose tip is directed from the outside to the inside of the suction port. In the pump device according to any one of claims 1 to 9,
2. A pump device according to claim 1, wherein a second check valve that allows fluid to flow out and blocks fluid from flowing in is disposed at the discharge port. The pump device according to claim 10,
The pump device characterized in that the second check valve is a duckbill valve whose tip is directed from the inside of the discharge port to the outside.

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