JP2008295114A - Electric response fluid pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric response fluid pump producing a practically sufficient pressure. <P>SOLUTION: A boosting unit 10 includes an introduction channel 13 for introducing electric response fluid and having counter walls becoming narrower gradually from the introduction side toward the discharge side, electrodes 15 and 16 provided on the counter walls of the introduction channel 13 while making a predetermined angle, and a narrow channel 14 connected to the discharge side of the introduction channel 13 and boosting the pressure of the conduction channel 13 in the circulation process. A DC power supply 20 applies a DC voltage to the electrodes 15 and 16. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electrically responsive fluid pump using an EHD (Electro Hydro Dynamics Phenomenon) pumping phenomenon that occurs in an electrically responsive fluid.

Various electric response fluid pumps using the EHD pumping phenomenon have been proposed so far (for example, Patent Documents 1 and 2). These electric response fluid pumps apply a DC voltage of several kV to several tens of kV between both electrodes in a state where the first and second electrodes are opposed to each other with a predetermined interval in the electric response liquid. This utilizes the fact that the liquid flows due to the attractive force generated between the heterocharge layer made of ions ionized from the liquid and the electrode pair. Since this electrically responsive fluid pump uses the continuous flow of the electrically responsive fluid, a low noise pump without pulsation can be realized.
JP 2003-284316 A JP 2005-269809 A

  However, the above-described conventional electrically responsive fluid pump has a problem that it does not reach a practically sufficient pressure.

  An object of the present invention is to provide an electrically responsive fluid pump that can obtain a practically sufficient pressure.

  An electrically responsive fluid pump according to a first aspect of the present invention includes an introduction path for introducing an electrically responsive fluid, an electrode pair provided in the introduction path, the interval of which gradually decreases from the introduction side to the discharge side, and discharge of the introduction path And a voltage increasing means for applying a voltage to the electrode pair, and a voltage increasing unit that includes a narrow path that increases the pressure of the electrically responsive fluid that has passed through the introduction path in the course of flow. .

  The electrically responsive fluid pump according to the second aspect of the present invention introduces or discharges the electrically responsive fluid so that the opposing walls gradually narrow from one side to the other side and the opposing walls are opposed to each other. First and second introduction / discharge passages arranged symmetrically to each other, and first and second electrodes provided on opposing walls of the first and second introduction / discharge passages and facing each other at a predetermined angle. A pair and a narrowing connected to the side where the opposing wall of the first and second introduction / discharge passages is narrowed to increase the pressure of the electrically responsive fluid that has passed through the first or second introduction / discharge passage in the course of flow. A step-up unit having a path; a power source for generating a voltage to be applied to the first or second electrode pair; and a switch means for applying the voltage to one of the first and second electrode pairs. It is characterized by having.

  According to the present invention, the fluid moves toward the narrow path by the electrode pair facing each other at a predetermined angle, and the pressure of the fluid is sufficiently increased in the process of passing the fluid through the narrow path. Can be obtained.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  1A and 1B are diagrams showing an EHD pump according to a first embodiment of the present invention, in which FIG. 1A is a plan view with a part cut away, FIG. 1B is a perspective view of the main part, and FIG. (c) is the perspective view which notched a part of (b).

  The EHD pump includes a booster unit 10 and a DC power supply 20. The pressure increasing unit 10 includes a cylindrical flow pipe 11 having a rectangular cross section with one end being a liquid inlet 11a and the other end being a liquid discharge opening 11b, and a cell 12 disposed inside the flow pipe 11; Is provided. The cell 12 is formed obliquely so that the end surface on the inlet 11 a side forms a predetermined angle with respect to the side wall of the flow tube 11, and the end surface on the discharge port 11 b side with respect to the side wall of the flow tube 11. It is formed at a right angle and is brought into close contact with the inner surface of the side wall of the flow tube 11 through the long side surface, and a predetermined gap is formed between the short side surface and the inner surface of the side wall of the flow tube 11. A liquid introduction path 13 is formed between the end surface formed obliquely with respect to the inner surface of the side wall of the flow pipe 11 and the inner surface of the side wall facing the end surface, and the end surface and the inner surface of the side wall facing the end surface are formed. Flat electrodes 15 and 16 are provided. The gap between the short side surface of the cell 12 following the introduction channel 13 and the inner surface of the side wall of the flow pipe 11 forms a narrow channel 14.

  According to the EHD pump configured as described above, by applying a DC voltage from the DC power supply 20 to the electrodes 15 and 16, the liquid is caused by the attractive force between the ions ionized from the liquid in the introduction path 13 and the electrodes 15 and 16. It moves from the introduction path 13 toward the narrow path 14. The liquid introduced into the narrow path 14 is pressurized and discharged from the discharge port 11b side. In this embodiment, a DC voltage is applied to the electrodes 15 and 16, but since the direction of fluid flow does not change depending on the polarity of the voltage, an AC voltage is applied to the electrodes 15 and 16 instead of the DC voltage. You may do it.

  Here, as shown in FIG. 2, the electrode angle θ is 75 °, the channel length l of the narrow channel 14 is 10 mm, the width w is 10 mm, the gap g is 1 mm, and the applied DC voltage is 1 to 10 V / mm. Using hydrofluoroether (HFE-7200, HFE-7300, manufactured by Sumitomo 3M), fluorine-modified silicone oil, silicone oil, and DBDN (di-n-butyl dodecanedioate) as electrical responsive fluids The discharge pressure of the electrically responsive fluid was measured by the pressure sensor 17. A graph of the discharge pressure against the applied voltage is shown in FIG. Similarly, a graph of the current value with respect to the applied voltage is shown in FIG.

  As is clear from FIG. 3, in all the fluids used, the pressure increased with voltage application, and when the fluorine-modified silicone oil showing the highest pressure was used, when the applied voltage was 10 kV / mm, the pressure was 3 It rose to 5 kPa. Further, the current value was 16 μA at maximum even in the highest fluid, and was not a particularly high value.

  FIG. 5 shows the relationship between the electrode angle θ and the pressure, and FIG. 6 shows the relationship between the electrode angle θ and the current. As described above, the dimensional relationship of the boosting unit 1 was HFE-7200, and the applied voltage was changed by 1 kV / mm from 5 to 10 kV / mm. As a result, as is apparent from FIG. 5, it was found that the pressure increased after the electrode angle exceeded 0 °, and a high pressure was obtained even at 90 ° or more, and in particular, 60 to 75 ° was desirable. The highest pressure was 4 kPa at an electrode angle of 75 ° when the applied voltage was 10 kV / mm. Further, as shown in FIG. 6, the current value was stable at a low value when the electrode angle was in the range of 15 to 90 °.

  FIG. 7 is a graph showing the relationship between the flow path length l of the narrow portion 14 and the pressure.

  For each of the cases where the electrode angle θ is 30 ° and the voltage applied to the electrodes is 1, 2, 3,..., 9, 10 kV / mm, the gap g of the narrow path 14 is 2 mm, the width w is 20 mm, and the flow path The pressure was measured by changing the length to 1, 2, 3, 4, 5, 10, 15, 20, 25, and 30 mm. In addition, the above-mentioned HFE-7200 was used as a fluid. As is clear from FIG. 7, it was found that when the channel length was 2 mm or more, a stable pressure was obtained, and a constant pressure was maintained even when the channel length was increased, and the variation factor decreased as the channel length increased. The flow path length of 2 mm or more is an optimum value under the above experimental conditions, and is a value that varies depending on the characteristics of the fluid such as the size of the experimental apparatus and the viscosity of the fluid.

  FIGS. 8A and 8B are diagrams showing an EHD pump according to a second embodiment of the present invention. FIG. 8A is a plan view with a part cut away, and FIG. 8B is a part with a part cut out. FIG.

  In this embodiment, the cell 32 disposed inside the flow pipe 31 constituting the pressure increasing unit 30 is symmetrical with the two cells 12 in the first embodiment in contact with two perpendicular end faces in the direction of fluid flow. It is made to arrange. Further, a first introduction / discharge path 33 is formed between one end surface formed obliquely with respect to the inner surface of the side wall of the flow pipe 31 and the inner surface of the side wall opposed thereto, and the other end surface formed obliquely. And a second introduction / discharge passage 34 is formed between the inner wall and the inner surface of the opposite side wall. Flat electrodes 35 and 36 are provided on the end surfaces forming these introduction and discharge passages 33 and 34, and electrodes 35 to 36 are provided on the inner surface of the side wall of the flow pipe 31 so as to face these electrodes 35 and 36. One flat electrode 37 covering 36 is provided. Further, the gap between the short side surface of the cell 32 connecting the introduction / discharge passages 33 and 34 and the inner surface of the side wall of the flow pipe 31 forms a narrow passage 38.

  A DC voltage from the DC power supply 20 is alternatively applied to the electrodes 35, 36 and the electrode 37 via the changeover switch 21.

  According to such a configuration, the flow direction of the fluid can be switched by switching the changeover switch 21.

  FIGS. 9A and 9B are views showing an EHD pump according to a third embodiment of the present invention. FIG. 9A is a plan view with a part cut away, and FIG. FIG.

  In this embodiment, the cell 42 arranged inside the flow pipe 41 that constitutes the pressure increasing unit 40 has the side surfaces that are long in the direction perpendicular to the direction of the fluid flow. They are arranged in contact and symmetrically. As a result, both ends of the cell 42 in the fluid flow direction are formed by two surfaces each having an acute predetermined angle, and both side surfaces of the both ends and inner surfaces of both side walls of the flow pipe 41 facing the both sides are formed. The first and second introduction / discharge paths 43 and 44 are formed between the two. At both ends of the cell 42, V-shaped electrodes 45, 46 having a predetermined angle along two surfaces forming a predetermined angle are provided, and inner surfaces of both side walls of the flow pipe 41 facing these electrodes 45, 46 are provided. Flat electrodes 47 and 48 are provided, respectively. Further, narrow passages 49 and 50 are formed in the gaps between the both side surfaces of the cell 42 and the flow pipe 41, respectively.

  Also in this embodiment, a direct current voltage from the direct current power source 20 is alternatively applied to the electrodes 45 and 46 and the electrodes 47 and 48 via the changeover switch 21, thereby allowing fluid to flow. The flow direction can be switched.

  According to this embodiment, since two narrow paths can be provided in a small space, the boosting effect can be further enhanced.

  FIG. 10 is a diagram showing an EHD pump according to the fourth embodiment of the present invention.

  In this embodiment, a plurality of booster units 10 of the first embodiment are arranged in series. Inside the flow pipe 51, the cells 12 in the first embodiment are arranged in a plurality of stages in series. A DC voltage is applied to the electrode 15 of each stage from the DC power supply 20 via the switch 22. The electrode 17 is formed as one electrode 17 so as to cover the whole of the plurality of electrodes 15. In this way, a higher pressure can be obtained by connecting the booster units 10 in series.

  FIG. 11 is a diagram showing an EHD pump according to the fifth embodiment of the present invention.

  In this embodiment, a plurality of booster units 10 of the first embodiment are arranged in parallel. A plurality of cells 12 in the first embodiment are arranged in parallel inside the flow pipe 61. Thus, by connecting a plurality of boosting units 10 in parallel, the flow rate can be increased as compared with one boosting unit.

  FIG. 12 is a diagram showing an EHD pump according to the sixth embodiment of the present invention.

  In this embodiment, the arrangement of the electrodes is changed without changing the basic principle of generating pressure. That is, in this embodiment, the side wall of the flow pipe 71 constituting the boosting unit 70 has a thick portion 71a and a thin portion 71b, and the thick portion 71a and the thin portion 71b are interposed via the inclined surface 71c. It is connected. One side wall has a thin portion 71b on the fluid introduction side (or discharge side), and the other side wall has a thin portion 71b on the fluid discharge side (or introduction side). As a result, first and second introduction / discharge paths 73 and 74 are formed at both ends of the flow pipe 71. A narrow path 75 is formed in a portion where the thick portions 71a face each other. Electrodes 76 and 77 are provided on the inclined surfaces 71 c on both side walls of the flow pipe 71, and electrodes 78 and 79 are provided on the thick portion 71 a facing the electrodes 76 and 77, respectively.

  FIG. 13 is a diagram showing an EHD pump according to the seventh embodiment of the present invention.

  This embodiment is an example in which a plurality of boosting units 70 of the sixth embodiment are provided in parallel. Inside the flow pipe 81, a plurality of parallelogram cells 82 are arranged in parallel with a predetermined gap, and the electrode structure similar to that of the sixth embodiment is provided on the side walls of the cells 82 and the flow pipe 81. Is formed.

  Also according to this embodiment, the flow rate of the pump can be increased.

  FIG. 14 is a diagram showing an EHD pump according to the eighth embodiment of the present invention.

  This embodiment is an example in which a plurality of booster units 70 of the sixth embodiment are arranged in series. In this embodiment, the inner surface of the side wall of the flow pipe 91 is a gentle zigzag surface formed by combining inclined surfaces. By disposing the inner surfaces of the side walls so as to be opposed to each other, the narrow path 92 and the introduction / discharge paths 93 on both sides thereof are arranged. And form.

  This embodiment can also increase the pump pressure.

  FIGS. 15A and 15B are views showing an EHD pump according to a ninth embodiment of the present invention, in which FIG. 15A is a partially cutaway plan view, and FIG. 15B is a perspective view.

  This embodiment is an example in which a plurality of booster units 40 of the third embodiment shown in FIG. 9 are arranged in series.

  In the pump case 101, four grooves 102a to 102d are formed in parallel, and an introduction port (or discharge port) 103 is provided on one end side of the first stage groove 102a, and one end side of the fourth stage groove 102d. A discharge port (or introduction port) 104 is provided at the top. The other ends of the first-stage groove 102a and the second-stage groove 102b, and the other-end side of the third-stage groove 102c and the fourth-stage groove 102d are connected by a U-shaped groove 105, respectively. One end side of 102 b and the third stage groove 102 c are connected by a U-shaped groove 106. Thereby, each groove | channel 102a-102d is connected in series. In these grooves 102a to 102d, the cells 42 in the third embodiment are arranged in series in multiple stages.

  According to this structure, a sufficient pressure can be obtained because a sufficient distance can be ensured by arranging a sufficient number of booster units 40 in a small space.

  FIG. 16 is a partially cutaway perspective view showing a main part of an EHD pump according to the tenth embodiment of the present invention.

  In this embodiment, a booster unit 110 is formed by coaxially disposing a cell 112 in which a cone and a column are combined inside a cylindrical flow pipe 111. The booster unit 110 uses a cylindrical electrode 113 and a conical electrode 114.

  According to this configuration, since the electrode and the peripheral shape are circular curved surfaces, the utilization efficiency in the circumferential direction is increased, and more efficient boosting is possible. The cells 112 may be held by connecting a part of the circumferential direction with the flow pipe 111 or extending the axial center part and connecting with a part of the flow pipe 111.

  FIG. 17 is a partially cutaway perspective view showing a main part of an EHD pump according to the eleventh embodiment of the present invention.

  In this embodiment, inside the cylindrical flow pipe 121, a cell 122 having a cone coupled to the downstream side of the cell 112 of the embodiment of FIG. Is.

  FIG. 18 shows an example in which a plurality of such boosting units 120 are arranged in multiple stages, and FIG. 19 shows an example in which a plurality of boosting units 120 are provided in parallel.

  Further, in each of the embodiments described above, each electrode pair is planar, but as shown in FIG. 20, one of the electrode pairs can be curved.

  In FIG. 5A, among the flow pipe 131 and the cell 132 constituting the pressure increasing unit 130, the surface on the inlet side of the cell 132 is a convex curved surface that is inclined obliquely, and the electrode 135 having a convex curved surface on the convex curved surface. Is provided, and an electrode 136 is provided on the inner surface of the side wall of the flow pipe 131 opposite to this. In FIG. 5B, of the flow-through pipe 141 and the cell 142 constituting the boosting unit 140, the surface on the inlet side of the cell 142 is a concave curved surface that is inclined obliquely, and the concave curved surface has a concave curved surface. The electrode 135 is provided, and the electrode 136 is provided on the inner surface of the side wall of the flow pipe 131 facing the electrode 135.

  In both the convex and concave cases, a sufficient pressure can be obtained with respect to the applied voltage, as shown in FIGS.

  Although various examples have been described above, such a pump can be applied to various uses such as a hydrostatic bearing, a fluid bearing, power of a robot arm, and cooling in a sealed space.

It is a figure which shows the EHD pump which concerns on the 1st Embodiment of this invention. It is a figure for demonstrating the dimension of the principal part of the pump. It is a graph which shows the relationship between the applied voltage and discharge pressure of the pump. It is a graph which shows the relationship between the applied voltage and current value of the pump. It is a graph which shows the relationship between the electrode angle and pressure of the pump. It is a graph which shows the relationship between the electrode angle of the same pump, and an electric current value. It is a graph which shows the relationship between the flow path length of the narrow path of the pump, and pressure. It is a figure which shows the EHD pump which concerns on the 2nd Embodiment of this invention. It is a figure which shows the EHD pump which concerns on the 3rd Embodiment of this invention. It is a figure which shows the EHD pump which concerns on the 4th Embodiment of this invention. It is a figure which shows the EHD pump which concerns on the 5th Embodiment of this invention. It is a figure which shows the EHD pump which concerns on the 6th Embodiment of this invention. It is a figure which shows the EHD pump which concerns on the 7th Embodiment of this invention. It is a figure which shows the EHD pump which concerns on the 8th Embodiment of this invention. It is a figure which shows the EHD pump which concerns on the 9th Embodiment of this invention. It is a figure which shows the EHD pump which concerns on the 10th Embodiment of this invention. It is a figure which shows the EHD pump which concerns on the 11th Embodiment of this invention. It is a figure which shows the EHD pump which concerns on the 12th Embodiment of this invention. It is a figure which shows the EHD pump which concerns on the 13th Embodiment of this invention. It is a figure which shows the EHD pump which concerns on the 14th Embodiment of this invention. It is a graph which shows the relationship of the pressure with respect to the applied voltage of the EHD pump shown to Fig.20 (a). It is a graph which shows the relationship of the pressure with respect to the applied voltage of the EHD pump shown in FIG.20 (b).

Explanation of symbols

  10, 30, 40, 70, 110, 120, 130, 140 ... boosting unit, 11, 31, 41, 51, 61, 71, 81, 91, 111, 121, 131, 141 ... flow pipe, 12, 32 , 42, 82, 112, 122, 132, 142 ... cell, 13 ... introduction route, 14, 38, 49, 50, 75, 92 ... narrow path, 15, 16, 35-37, 45-48, 76-79. , 135, 136, 145, 146... Electrodes, 20... DC power supply, 33, 34, 73, 74, 93.

Claims (6)

An introduction path that introduces an electrical response fluid, an electrode pair that is provided in the introduction path and whose interval gradually decreases from the introduction side to the discharge side, and an electrical response fluid that is connected to the discharge side of the introduction path and passes through the introduction path. A boost unit with a narrow path that boosts the pressure in the flow process;
An electrically responsive fluid pump comprising: voltage applying means for applying a voltage to the electrode pair. The first and second introduction and discharge are arranged symmetrically so that the opposite walls are gradually narrowed from one side to the other side and the opposite walls are opposed to each other by introducing or discharging the electrically responsive fluid. A first electrode pair and a second electrode pair which are provided on opposing walls of the first and second introduction / discharge paths and are opposed to each other at a predetermined angle, and the first and second introduction / discharge paths A pressure increasing unit provided with a narrow path that is connected to the side on which the opposing wall is narrowed and pressurizes the electrically responsive fluid that has passed through the first or second introduction / discharge path in the course of flow;
A power source for generating a voltage to be applied to the first or second electrode pair;
An electrically responsive fluid pump comprising: switch means for applying the voltage to one of the first and second electrode pairs.   3. The electric response fluid pump according to claim 1, wherein a plurality of the boosting units are provided in series.   3. The electric response fluid pump according to claim 1, wherein a plurality of the boosting units are provided in parallel.   5. The electrically responsive fluid pump according to claim 1, wherein an angle formed by the electrode pair is greater than 0 ° and 90 ° or less.   6. The electrically responsive fluid pump according to claim 1, wherein at least one of the electrode pairs is a flat surface or a curved surface.

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