Ionic wind generator

Abstract

To suitably generate ionic wind in a case where ions generated in a generating section are accelerated at an acceleration section.SOLUTION: An ionic wind generator includes a first electrode, a second electrode disposed away from the first electrode, a third electrode disposed at a position farther away from the first electrode than the second electrode, a first power supply applying voltage that induces a corona discharge between the first electrode and the second electrode, and a second power supply applying voltage between the second electrode and the third electrode. The second electrode has an insulation coating on a surface thereof.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an ion wind generator that generates an ion wind.

Background Art

[0002] Conventionally, an ion wind generator that accelerates ions generated by discharge along an electric field to create an air current (ion wind) is known. In this type of ion wind generator, a technique has been proposed in which ions generated by a pair of electrodes are further accelerated by another electrode disposed in the downstream (for example, see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to suitably generate an ion wind when ions generated in a generation unit are accelerated in an acceleration unit.

Means for Solving the Problems

[0005] To achieve the above object, an embodiment of the present invention is an ion wind generator, comprising: a first electrode; a second electrode disposed apart from the first electrode; a third electrode disposed at a position farther from the first electrode than the second electrode; a first power source that applies a voltage for inducing a corona discharge between the first electrode and the second electrode; a second power source that applies a voltage between the second electrode and the third electrode; and the second electrode has an insulating film on its surface.

Advantages of the Invention

[0006] According to the present invention, since the second electrode has an insulating film on its surface, ions traveling from the first electrode toward the second electrode are not absorbed by the second electrode but are accelerated toward the third electrode. In addition, since the dielectric strength of the second electrode is improved, the voltage applied between the electrodes can be increased, and thus the speed of the ions can be further increased. Therefore, when ions generated at the generation part of the first electrode and the second electrode are accelerated at the acceleration part of the second electrode and the third electrode, an ion wind can be suitably generated.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0008] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0009] [Configuration of Ion Wind Generating Device] FIG. 1 is an external view of an ion wind generating device 1 according to the present embodiment, FIG. 2 is a cross-sectional view showing a schematic configuration of the ion wind generating device 1, and FIG. 3 is a perspective view showing an electrode unit 2 included in the ion wind generating device 1. The ion wind generator 1 accelerates ions generated by discharge along an electric field to generate an air current (ion wind). Specifically, as shown in FIGS. 1 to 3, the ion wind generator 1 includes an electrode unit 2 that generates an ion wind, a nozzle tube 3 that supports the electrode unit 2, and a first power source 41 and a second power source 42 that apply a voltage to the electrode unit 2.

[0010] The nozzle tube 3 is formed, for example, in a cylindrical shape with a predetermined length, allows an air current to flow inside, and supports the electrode unit 2. The nozzle tube 3 is an example of the tubular member according to the present invention. Hereinafter, the direction along the central axis of the nozzle tube 3 (the vertical direction in FIGS. 1 to 3) is referred to as the "axial direction", the direction perpendicular to the central axis is referred to as the "radial direction", and the rotational direction centered on the central axis is referred to as the "circumferential direction". Also, regarding both sides in the axial direction, depending on the direction of the air current, it may be simply referred to as the "upstream side (the upper side in FIGS. 1 to 3)" and the "downstream side (the lower side in FIGS. 1 to 3)" (see FIG. 5).

[0011] The electrode unit 2 includes a plurality of discharge electrodes 23, a plurality of reference electrodes 24, and an acceleration electrode 25. The electrode unit 2 generates and moves ions by the voltage applied between the discharge electrode 23 and the reference electrode 24, and accelerates the ions by the voltage applied between the reference electrode 24 and the acceleration electrode 25. The discharge electrode 23, the reference electrode 24, and the acceleration electrode 25 are examples of the first electrode, the second electrode, and the third electrode according to the present invention.

[0012] The plurality of discharge electrodes 23 are arranged at equal intervals over the entire circumference along the circumferential direction on the outer peripheral portion of the nozzle tube 3 at an axial position in the middle of the nozzle tube 3. Each discharge electrode 23 is formed in a rod shape (linear shape) and is arranged to extend along the axial direction. In the wall portion of the nozzle tube 3 at the axial position where the discharge electrode 23 is arranged, a plurality of slits 31 that communicate the inside and outside of the nozzle tube 3 as air inlets are opened. The slits 31 are provided corresponding to the discharge electrodes 23, and are formed, for example, such that the corresponding discharge electrode 23 is located at the center in the circumferential direction. An insulating film is coated on the surface of the discharge electrode 23. The type of the insulating film is not particularly limited as long as it can improve the dielectric strength of the discharge electrode 23.

[0013] The plurality of reference electrodes 24 are paired with the plurality of discharge electrodes 23 correspondingly. Specifically, each reference electrode 24 is formed in a long plate shape and is disposed on the inner diameter side of the nozzle tube 3 rather than the corresponding discharge electrode 23. Each reference electrode 24 is erected from the inner wall of the nozzle tube 3 toward the inner diameter side and is disposed so as to extend along the radial direction. The corner 24a on the inner diameter side and the downstream side of each reference electrode 24 is formed in a rounded and smooth R shape so that no protruding portion is formed with respect to the acceleration electrode 25. Also, each reference electrode 24 is connected to GND (chassis GND).

[0014] The acceleration electrode 25 is formed in a slightly long cylindrical shape in the axial direction and is disposed at the central portion in the radial direction on the downstream side of the reference electrode 24 in the nozzle tube 3. Both axial ends of the acceleration electrode 25 are formed in a shape that bulges toward the tip. In particular, the upstream end portion 25a of the acceleration electrode 25 on the side close to the reference electrode 24 is formed in a rounded and gently bulging shape so that no protruding portion is formed with respect to the reference electrode 24.

[0015] The first power source 41 is a DC power source that applies a predetermined DC voltage for inducing a corona discharge between the corresponding discharge electrode 23 and the reference electrode 24. In the present embodiment, the negative electrode side of the first power source 41 is connected to each discharge electrode 23, and the positive electrode side is connected to each reference electrode 24. The second power source 42 is a DC power source that applies a predetermined DC voltage between the plurality of reference electrodes 24 and the acceleration electrode 25. The second power source 42 applies a voltage (three times in the example of FIG. 2) larger than the voltage of the first power source 41 between the plurality of reference electrodes 24 and the acceleration electrode 25. In the present embodiment, the negative electrode side of the second power source 42 is connected to the reference electrode 24, and the positive electrode side is connected to the acceleration electrode 25. The first power supply 41 and the second power supply 42 are connected to a control device (not shown) and controlled thereby. The control device is a computer that integrally controls the ion wind generator 1.

[0016] [Operation of Ion Wind Generator] Subsequently, the operation of the ion wind generator 1 will be described. FIGS. 4 and 5 are diagrams for explaining the movement of ions when the ion wind generator 1 is operated. FIG. 4 is a view of the electrode unit 2 seen from the axial direction, and FIG. 5 is a cross-sectional view in the axial direction. Note that the "−" marks surrounded by circles and the accompanying arrows shown in FIGS. 4 and 5 illustrate the images of the generated and moving ions, and do not necessarily mean the exact positions and movements of the ions.

[0017] When the ion wind generator 1 is operated, the first power supply 41 applies a predetermined DC voltage between the discharge electrode 23 and the reference electrode 24. As a result, as shown in FIGS. 4 and 5, a corona discharge is induced between the corresponding discharge electrode 23 and the reference electrode 24. Then, the air around the discharge electrode 23 is ionized to generate ions. The negative ions generated at the discharge electrode 23 move toward the inner diameter side so as to gather at the center of the nozzle tube 3 by the electric field (electric field) generated between the discharge electrode 23 and the reference electrode 24.

[0018] On the other hand, a larger DC voltage is applied between the reference electrode 24 and the acceleration electrode 25 by the second power supply 42. As a result, the ions that have moved toward the inner diameter side from the discharge electrode 23 toward the reference electrode 24 are pulled by the acceleration electrode 25 by the strong electric field generated between the reference electrode 24 and the acceleration electrode 25, and are accelerated while changing the direction toward the downstream side in the axial direction. In this way, ions are generated between the discharge electrode 23 and the reference electrode 24, and these ions are accelerated between the reference electrode 24 and the acceleration electrode 25. As a result, an airflow that is suitably accelerated along the axial direction of the nozzle tube 3 is generated.

[0019] [Technical Effects of the Present Embodiment] As described above, according to the present embodiment, a corona discharge is induced between the discharge electrode (first electrode) 23 and the reference electrode (second electrode) 24, and ions are generated from the discharge electrode 23 toward the reference electrode 24. These ions are accelerated toward the acceleration electrode 25 by an electric field generated between the reference electrode 24 and the acceleration electrode (third electrode) 25. At this time, since the reference electrode 24 has an insulating film on its surface, the ions directed toward the reference electrode 24 are not absorbed by the reference electrode 24 and are accelerated toward the acceleration electrode 25. In addition, since the dielectric strength of the reference electrode 24 is improved, the voltage applied between the discharge electrode 23 and the reference electrode 24 and between the reference electrode 24 and the acceleration electrode 25 can be increased. For example, a high voltage that would cause a spark if there were no insulating film can be applied. As a result, the speed of the ions can be further increased. Therefore, when accelerating the ions generated at the discharge electrode 23 and the reference electrode 24 (generation part) by the reference electrode 24 and the acceleration electrode 25 (acceleration part), an ion wind can be suitably generated.

[0020] Further, according to the present embodiment, the first direction (axial direction) from the discharge electrode 23 toward the reference electrode 24 intersects the second direction (radial direction) from the reference electrode 24 toward the acceleration electrode 25. That is, the traveling direction of the ions at the time of generation is different from the traveling direction at the time of acceleration. Therefore, the discharge electrode 23 is disposed at a position deviated from the airflow with respect to the main airflow along the axial direction generated by the acceleration. As a result, compared with the case where the discharge electrode 23 is disposed on the airflow, the resistance (obstruction) of the airflow by the discharge electrode 23 can be reduced, and the airflow can be efficiently accelerated.

[0021] Further, according to the present embodiment, a slit 31 that communicates the inside and the outside is formed in the wall portion that supports the discharge electrode 23 in the nozzle tube 3 along the direction (axial direction) of the airflow. That is, since air is drawn into the nozzle tube 3 from the slit 31 by the airflow along the nozzle tube 3, the periphery of the discharge electrode 23 is decompressed. Therefore, a more stable corona discharge can be generated under a more decompressed low air pressure. As a result, ions can be generated more stably. In addition, the width of the slit 31 is preferably set so as to obtain an air pressure that facilitates discharge.

[0022] Moreover, according to the present embodiment, a plurality of discharge electrodes 23 are arranged along the circumferential direction on the outer peripheral portion of the nozzle tube 3, and each of the plurality of reference electrodes 24 is disposed on the inner diameter side of the nozzle tube 3 rather than the corresponding discharge electrode 23. As a result, ions generated at each discharge electrode 23 gather toward the center of the nozzle tube 3, so that the density of the ions can be suitably increased. Therefore, the thrust of the ion wind can be suitably increased, and thus the air flow can be efficiently accelerated.

[0023] Moreover, according to the present embodiment, the reference electrode 24 and the acceleration electrode 25 are formed in a rounded shape at the portions closer to each other (the corner portion 24a and the upstream end portion 25a). As a result, it is possible to make it difficult for dielectric breakdown to occur between the reference electrode 24 and the acceleration electrode 25. Consequently, the applied voltage between the reference electrode 24 and the acceleration electrode 25 can be increased to further increase the speed of the ions.

[0024] [Others] As described above, the embodiments of the present invention have been described, but the present invention is not limited to the above embodiments. For example, in the above embodiment, it is assumed that the first direction from the discharge electrode 23 toward the reference electrode 24 is orthogonal to the second direction from the reference electrode 24 toward the acceleration electrode 25. However, the first direction and the second direction only need to intersect with each other (that is, not be parallel). As a result, the effects obtained by changing the above-described directions can be obtained. In this case, a slit cannot be set, but the ions can be accelerated step by step by acceleration at the generation portion and acceleration at the acceleration electrode. Furthermore, the first direction and the second direction may be the same direction including parallel. Even in this case, an insulating film may be provided on the surface of the reference electrode 24.

[0025] Further, a plurality of ion wind generators 1 may be stacked in multiple stages in the axial direction of the nozzle tube 3. Thereby, the airflow (ion wind) generated by each ion wind generator 1 can be efficiently accelerated.

[0026] Also, an insulating film may be provided on the upstream end portion 25a of the acceleration electrode 25. Thereby, it is possible to further reduce the occurrence of dielectric breakdown between the reference electrode 24 and the acceleration electrode 25. As a result, the applied voltage between the reference electrode 24 and the acceleration electrode 25 can be increased to increase the speed of the ions.

[0027] Also, the application target of the ion wind generator according to the present invention is not particularly limited. For example, it can also be applied as a thrust source of an aircraft or the like. In addition, the details shown in the above embodiments can be appropriately changed without departing from the gist of the invention.

Explanation of Reference Numerals

[0028] 1 Ion wind generator 2 Electrode unit 3 Nozzle tube (tubular member) 23 Discharge electrode (first electrode) 24 Reference electrode (second electrode) 24a Corner portion 25 Acceleration electrode (third electrode) 25a Upstream end portion 31 Slit 41 First power source 42 Second power source

Claims

1. a first electrode, a second electrode disposed at a distance from the first electrode, a third electrode disposed at a position farther from the first electrode than the second electrode, a first power source for applying a voltage for inducing a corona discharge between the first electrode and the second electrode, a second power source for applying a voltage between the second electrode and the third electrode, comprising, wherein the second electrode has an insulating film on its surface, an ion wind generating device.

2. The ion wind generating device according to claim 1, wherein a first direction from the first electrode toward the second electrode intersects a second direction from the second electrode toward the third electrode.

3. The ion wind generating device according to claim 2, further comprising a tubular member that supports the first electrode, the second electrode, and the third electrode and extends along the second direction, wherein the tubular member supports the first electrode on a wall portion, and a slit communicating the inside and the outside is formed in the wall portion that supports the first electrode.

4. The ion wind generating device according to claim 2, further comprising a tubular member that supports the first electrode, the second electrode, and the third electrode and extends along the second direction, wherein a plurality of the first electrodes and a plurality of the second electrodes are provided so as to correspond to each other, the plurality of first electrodes are arranged along the circumferential direction on the outer peripheral portion of the tubular member, and each of the plurality of second electrodes is disposed on the inner diameter side of the tubular member closer to the inside than the corresponding first electrode.

5. The ion wind generating device according to claim 1, wherein portions of the second electrode and the third electrode closer to each other are formed in a rounded shape. ​

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