JP7108942B2 - discharge device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge device, and more particularly to a discharge device provided with a discharge electrode and a voltage applying section for applying a voltage thereto.

2. Description of the Related Art Conventionally, a discharge device provided with a discharge electrode and a voltage applying section has been provided. As a discharge device, a voltage is applied to a discharge electrode by a voltage applying unit, and a corona discharge is generated at the discharge electrode to generate air ions. There is known an apparatus for generating a charged fine particle liquid containing radicals (see, for example, Patent Document 1).

JP 2011-67738 A

In the discharge device, the energy input is increased to increase the amount of air ions, radicals, and charged fine particle liquid containing them (hereinafter, air ions, radicals, and charged fine particle liquid are collectively referred to as "active ingredients"). There is a demand to increase it and a demand to suppress the generation of ozone at this time. However, it is difficult for the conventional discharge device described above to satisfy both of these requirements.

SUMMARY OF THE INVENTION An object of the present invention is to propose a discharge device and a method of manufacturing the same, which can increase the amount of active ingredients produced while suppressing an increase in ozone at this time.

In order to solve the above-mentioned problems, the discharge device of the present invention comprises a discharge electrode and a voltage applying section that causes the discharge electrode to generate a discharge further developed from the corona discharge. The discharge is a discharge that intermittently generates a discharge path extending from the discharge electrode to the surroundings due to dielectric breakdown, and is a discharge in which an instantaneous current flows two to ten times as much as a corona discharge.

ADVANTAGE OF THE INVENTION The electric discharge apparatus of this invention is effective in the ability to increase the production amount of an active ingredient, and to suppress that ozone increases at this time.

FIG. 1 is a schematic diagram showing the discharge device of the first embodiment. FIG. 2A is a graph diagram schematically showing current flowing in corona discharge, and FIG. 2B is a graph diagram schematically showing current flowing in reader discharge. FIG. 3A is a schematic diagram showing the discharge device of the second embodiment, and FIG. 3B is a schematic diagram showing a modification of the same discharge device. FIG. 4A is a schematic diagram showing a discharge device of a third embodiment, and FIG. 4B is a schematic diagram showing a modification of the same discharge device. FIG. 5 is a schematic diagram showing a discharge device of a fourth embodiment. 6A is a perspective view showing a main part of a discharge device according to a fifth embodiment, FIG. 6B is a perspective view showing a main part of a discharge device according to a sixth embodiment, and FIG. 6C is a seventh embodiment. 1 is a perspective view showing a main part of the discharge device of FIG. FIG. 7 is a perspective view showing the discharge device of the eighth embodiment. FIG. 8 is a plan view showing the same discharge device. FIG. 9 is a side sectional view showing the same discharge device. FIG. 10A is a plan view showing a modification of the discharge device, and FIG. 10B is a plan view showing another modification of the discharge device. FIG. 11 is a plan view showing a main part of another modification of the discharge device same as the above. FIG. 12A is a side view showing a main part of another modification of the discharge device, and FIG. 12B is an enlarged view of part A in FIG. 12A. 13A and 13B are cross-sectional views showing a process of forming the needle-like electrode portion of the modification shown in FIGS. 12A and 12B. FIG. 14 is a perspective view showing a main part of another modification of the discharge device same as the above. FIG. 15A is a bottom view showing the discharge device of the ninth embodiment, and FIG. 15B is a perspective view showing a case where the same discharge device is provided with a lid. FIG. 16 is a perspective view showing a modification of the same discharge device. FIG. 17 is a perspective view showing another modification of the above discharge device. 18A is a graph showing the relationship between the length of the wiring between the counter electrode and the resistor and the amount of the active ingredient, and FIG. 18B is a graph showing the relationship between the length of the wiring between the voltage applying section and the resistor and the amount of the active ingredient. . FIG. 19 is a schematic diagram showing the apparatus that performed the measurements of the graphical representations of FIGS. 18A and 18B. FIG. 20 is a plan view showing the essential parts of the discharge device of the tenth embodiment; FIG. 21 is a sectional view taken along line aa of FIG. 20; FIG. 21 is a cross-sectional view taken along line bb of FIG. 20; FIG. 23 is a block diagram showing the essential parts of the discharge device of the eleventh embodiment. FIG. 24 is a block diagram showing a main part of a modification of the above discharge device.

A first invention is a discharge device comprising a discharge electrode and a voltage applying section that applies a voltage to the discharge electrode and causes the discharge electrode to generate a discharge further developed from corona discharge. The discharge is a discharge that intermittently generates a discharge path extending from the discharge electrode to the surroundings and having a dielectric breakdown. As a result, it is possible to increase the production amount of the active ingredient, and at this time, it is possible to suppress the increase in ozone.

In a second invention, in particular, the first invention further comprises a liquid supply section that supplies liquid to the discharge electrode. The discharge electrostatically atomizes the liquid supplied to the discharge electrode. As a result, it is possible to increase the amount of charged fine particle liquid generated, and at this time, it is possible to suppress an increase in ozone.

A third invention, in particular, in the first or second invention, further comprises a counter electrode located opposite to the discharge electrode. The discharge intermittently generates a discharge path between the discharge electrode and the counter electrode, in which insulation is broken so as to connect the two. This makes it possible to stably generate a discharge that intermittently generates a discharge path with dielectric breakdown between the discharge electrode and the counter electrode.

In a fourth invention, particularly in the third invention, the counter electrode has a needle-like electrode portion facing the discharge electrode. This makes it possible to stably generate a discharge that intermittently generates a discharge path with a dielectric breakdown between the discharge electrode and the needle-like electrode portion.

In a fifth aspect, in particular, in the fourth aspect, the needle-like electrode portion has a tip end portion and a base end portion on opposite sides, the discharge electrode has an axial direction, and the The distance between the tip portion and the discharge electrode is smaller than the distance between the base portion and the discharge electrode in the axial direction. This makes it possible to stably generate a discharge that intermittently generates a discharge path with a dielectric breakdown between the discharge electrode and the needle-like electrode portion.

In a sixth aspect, in particular, in the fifth aspect, the counter electrode includes a supporting electrode portion held in a posture orthogonal to the axial direction, and interposed between the supporting electrode portion and the needle-like electrode portion. A step portion is further provided. The distance between the base end portion and the discharge electrode in the axial direction is greater than the distance between the support electrode portion and the discharge electrode in the axial direction. As a result, it is possible to prevent the distal end portion of the needle-like electrode portion from protruding greatly, and to prevent deformation of the needle-like electrode portion.

In a seventh aspect, in particular, in any one of the fourth to sixth aspects, the needle-like electrode portion has a groove for suppressing deformation of the needle-like electrode portion, and the groove is formed by the needle. A part of the needle-like electrode portion is formed by bending in the thickness direction of the needle-like electrode portion. As a result, the geometrical moment of inertia of the needle electrode portion can be increased, and deformation of the needle electrode portion can be suppressed.

In an eighth aspect, in particular, in the fourth aspect, the counter electrode further includes a support electrode portion that supports the needle electrode portion, and the needle electrode portion and the support electrode portion are made of different materials. It is a member. This makes it possible to increase the resistance of the needle-like electrode portion to reader discharge while suppressing an increase in cost.

According to a ninth invention, in particular, in any one of the fourth to eighth inventions, the counter electrode includes a plurality of needle-like electrode portions. As a result, the generated active ingredient is efficiently released to the outside.

In a tenth aspect, particularly in the ninth aspect, the tip portions of the plurality of needle-like electrode portions are positioned on the same circle. Thereby, the generated active ingredient is more efficiently released to the outside.

In an eleventh aspect, in particular, in the tenth aspect, tip portions of the plurality of needle-like electrode portions are positioned equidistantly from each other in the circumferential direction of the same circle. Thereby, the generated active ingredient is more efficiently released to the outside.

In a twelfth invention, in particular, in any one of the ninth to eleventh inventions, each of the plurality of needle-like electrode portions has a rounded tip portion. As a result, it is possible to prevent large variations in intensity of electric field concentration from occurring due to manufacturing variations in the plurality of needle-shaped electrode portions.

In a thirteenth invention, in particular, in any one of the ninth to twelfth inventions, each of the plurality of needle-like electrode portions is a strip-shaped electrode portion having a thickness, and each of the plurality of needle-like electrode portions Of the edges in the thickness direction, the portions near the discharge electrodes are chamfered. As a result, it is possible to prevent large variations in intensity of electric field concentration from occurring due to manufacturing variations in the plurality of needle-shaped electrode portions.

In a fourteenth aspect, in particular, in any one of the ninth to thirteenth aspects, the plurality of needle-like electrode portions are three or more needle-like electrode portions positioned apart from each other. Thereby, the generated active ingredient is more efficiently released to the outside.

In a fifteenth aspect, in particular, in the fourteenth aspect, the counter electrode further includes an opening in which the three or more needle-like electrode portions are arranged, and the opening area of the opening is the three or more. larger than the total area of the needle-like electrode part. This makes it easier for corona discharge to progress to reader discharge.

In a sixteenth aspect, particularly in the third aspect, the counter electrode has at least one sharp convex surface facing the discharge electrode and a facing surface facing the discharge electrode, and the facing surface comprises: It has a flat surface, a concave curved surface, or a combination of these surfaces. As a result, electric field concentration tends to occur at the tip portion of the discharge electrode.

According to a seventeenth invention, in particular, in any one of the first to sixteenth inventions, it further comprises a capacitor electrically connected in parallel to the voltage applying section. Thereby, the discharge frequency of the reader discharge can be adjusted.

In an eighteenth aspect, in particular, in the method of manufacturing a discharge device according to the thirteenth aspect, the edge portions in the thickness direction of each of the plurality of needle-like electrode portions are crushed at once on one surface of the mold device. The chamfering is performed by Thereby, the positions of the tip portions of the plurality of needle-like electrode portions are aligned at once.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the present invention is not limited to the embodiments described below, and it is also possible to appropriately combine the configurations of the following embodiments.

(First embodiment)
FIG. 1 shows the basic configuration of the discharge device of the first embodiment. The discharge device of this embodiment includes a discharge electrode 1 , a voltage application section 2 , a liquid supply section 3 , a counter electrode 4 and an electric path 5 .

The discharge electrode 1 is an elongated needle-like electrode. The discharge electrode 1 has a tip portion 13 on one end side in the axial direction and a base end portion 15 on the other end side in the axial direction (opposite side of the tip portion 13). The term "needle-like" used in the present text is not limited to those with sharply pointed tips, and includes those with rounded tips.

Voltage application unit 2 is electrically connected to discharge electrode 1 so as to apply a high voltage of about 7.0 kV to discharge electrode 1 . The discharge device of this embodiment includes a counter electrode 4 , and the voltage applying section 2 is configured to apply a high voltage between the discharge electrode 1 and the counter electrode 4 .

The liquid supply unit 3 is means for supplying a liquid 35 for electrostatic atomization to the discharge electrode 1. In the discharge device of this embodiment, the cooling unit 30 cools the discharge electrode 1 to generate condensed water. The liquid supply unit 3 is configured by. The cooling part 30 contacts the base end portion 15 of the discharge electrode 1 and cools the entire discharge electrode 1 through the base end portion 15 . The liquid 35 supplied to the discharge electrode 1 by the liquid supply unit 3 is condensed water generated on the discharge electrode 1 .

The counter electrode 4 is positioned facing the tip portion 13 of the discharge electrode 1 . The counter electrode 4 has an opening 43 in its central portion. The opening 43 penetrates through the counter electrode 4 in the thickness direction. The opening 43 is provided in a region of the counter electrode 4 that is closest to the distal end portion 13 of the discharge electrode 1 . The direction in which the opening 43 penetrates and the axial direction of the discharge electrode 1 are parallel to each other. The term "parallel" used in the text is not limited to strictly parallel, but includes substantially parallel.

The current-carrying path 5 is a current-carrying path that electrically connects the counter electrode 4 to the discharge electrode 1, and the voltage applying section 2 is arranged in the middle of the current-carrying path. That is, the conducting path 5 includes a first conducting path 51 electrically connecting the voltage applying section 2 and the counter electrode 4 and a second conducting path 52 electrically connecting the voltage applying section 2 and the discharge electrode 1 .

In the discharge device of the present embodiment, a high voltage of about 7.0 kV is applied between the discharge electrode 1 and the counter electrode 4 by the voltage applying section 2 while the liquid 35 is held on the discharge electrode 1 . Thereby, discharge occurs between the discharge electrode 1 and the counter electrode 4 .

In the discharge device of this embodiment, a local corona discharge is first generated at the tip portion 13 of the discharge electrode 1 (the tip of the liquid 35 held at the tip portion 13), and this corona discharge is converted into a high-energy discharge. advance to. This high-energy discharge is a form of discharge in which a discharge path extending from the discharge electrode 1 to the surroundings and having a dielectric breakdown (all-path breakdown) is intermittently generated. In the discharge device of the present embodiment, a discharge path is intermittently (pulse-like) generated by dielectric breakdown so as to connect the discharge electrode 1 and the counter electrode 4 . Such a form of discharge is called "leader discharge".

In the leader discharge, an instantaneous current about 2 to 10 times as large as that in the corona discharge flows through the discharge path where the insulation is broken between the discharge electrode 1 and the counter electrode 4 . FIG. 2A schematically shows current flowing in a corona discharge, and FIG. 2B schematically shows current flowing in a reader discharge developed from the corona discharge. In leader discharge, radicals are generated with greater energy than in corona discharge, and a large amount of radicals about 2 to 10 times as large as those in corona discharge are generated.

Ozone is also generated when radicals are generated by the leader discharge. However, in the leader discharge, about 2 to 10 times more radicals are generated than in the corona discharge, whereas the amount of ozone generated is suppressed to the same extent as in the case of the corona discharge. In other words, the amount of ozone generated relative to the amount of radicals generated can be greatly suppressed by further developing the corona discharge to generate the leader discharge. It is believed that this is because the high-energy leader discharge destroys some of the ozone as it is emitted while being exposed to the leader discharge.

Here, the reader discharge will be further explained.

In general, when energy is applied between a pair of electrodes to generate a discharge, the form of the discharge develops into corona discharge, glow discharge, and arc discharge depending on the amount of energy applied.

A corona discharge is a discharge that is locally generated at one electrode and is not accompanied by dielectric breakdown between the electrodes. Glow discharge and arc discharge are discharges accompanied by dielectric breakdown between paired electrodes, and the dielectric breakdown discharge path continuously exists while energy is being supplied.

On the other hand, the leader discharge is accompanied by dielectric breakdown between the paired electrodes, but the dielectric breakdown does not exist continuously but occurs intermittently.

In the discharge device of the present embodiment, the electrical capacity of the voltage applying section 2 (capacity of electricity that can be discharged per unit time) is adjusted so that such a form of leader discharge occurs between the discharge electrode 1 and the counter electrode 4. is set. In other words, in the discharge device of the present embodiment, when the corona discharge progresses to dielectric breakdown, a large instantaneous current flows through the discharge path where the dielectric breakdown occurred, but immediately after that, the voltage drops and the discharge stops, and The electrical capacity of the voltage application unit 2 is set so that the voltage rises and the dielectric breakdown is repeated. This capacity setting realizes leader discharge in which instantaneous dielectric breakdown and discharge stop are alternately repeated, unlike glow discharge or arc discharge where dielectric breakdown continues.

As an example currently confirmed, the discharge frequency (the frequency of instantaneous current) in the reader discharge is about 50 Hz to 10 kHz, and the width of one pulse is about 200 ns at most. In this way, it is clearly different from glow discharge and arc discharge in that instantaneous discharge (state of high energy) and stop of discharge (state of low energy) are repeated.

In the discharge device of this embodiment, liquid 35 is supplied to discharge electrode 1 by liquid supply section 3 . Therefore, the liquid 35 is electrostatically atomized by high-energy leader discharge accompanied by intermittent dielectric breakdown, and a nanometer-sized charged fine particle liquid containing radicals is generated therein. The generated charged fine particle liquid is discharged to the outside through the opening 43 .

The charged fine particle liquid generated by leader discharge contains a large amount of radicals compared to the charged fine particle liquid generated by corona discharge, and the generation of ozone is suppressed to the same extent as in the case of corona discharge.

As described above, the discharge device of the present embodiment described with reference to FIG. It is also possible to configure without provision. In this case, air ions are generated by the reader discharge generated between the discharge electrode 1 and the counter electrode 4 .

Further, although the discharge device of this embodiment includes the counter electrode 4, it can be configured without the counter electrode 4. FIG. In this case, if a leader discharge is generated between the discharge electrode 1 and some member around the discharge electrode 1, the charged fine particle liquid is generated by the leader discharge. In the discharge device of this embodiment, it is also possible to omit both the liquid supply section 3 and the counter electrode 4 . In this case, if a leader discharge is generated between the discharge electrode 1 and some member around the discharge electrode 1, air ions are generated by the leader discharge.

(Second embodiment)
A discharge device of the second embodiment will be described with reference to FIGS. 3A and 3B. Note that detailed descriptions of the same configurations as those described in the first embodiment will be omitted.

FIG. 3A shows the basic configuration of the discharge device of this embodiment. The discharge device of this embodiment differs from that of the first embodiment in that the counter electrode 4 integrally includes a needle electrode portion 41 and a support electrode portion 42 that supports the needle electrode portion 41 .

The needle-shaped electrode portion 41 is an electrode portion that protrudes toward the discharge electrode 1 from a facing surface 420 of the support electrode portion 42 that faces the discharge electrode 1 . The needle-like electrode portion 41 has a sharp convex surface. The tip of the needle-like electrode portion 41 is positioned closest to the discharge electrode 1 in the entire counter electrode 4 . The needle-shaped electrode portion 41 is located near the opening 43 of the counter electrode 4 . Although the discharge device of the present embodiment includes one acicular electrode portion 41, it is also possible to include a plurality of acicular electrode portions 41. FIG.

The support electrode portion 42 is composed of a plate-shaped electrode portion 421 having a flat facing surface and a dome-shaped electrode portion 422 having a concavely curved facing surface. A facing surface 420 of the supporting electrode portion 42 is configured by facing surfaces of the electrode portion 421 and the electrode portion 422 . A facing surface 420 of the support electrode portion 42 has a shape in which a flat surface and a concave curved surface are combined.

Since the discharge device of the present embodiment has the above configuration, electric field concentration occurs at the needle electrode portion 41 of the counter electrode 4 and the tip portion 13 of the discharge electrode 1 (that is, the tip of the liquid 35 held at the tip portion 13). , leader discharge due to dielectric breakdown is stably generated between the needle electrode portion 41 of the counter electrode 4 and the tip portion 13 of the discharge electrode 1 . In addition, the facing surface 420 of the support electrode portion 42 further enhances the electric field concentration at the tip portion 13 of the discharge electrode 1 .

FIG. 3B shows a modification of the discharge device of this embodiment. In this modified example, the support electrode portion 42 is composed of a dome-shaped electrode portion 423 having a concavely curved facing surface. A facing surface 420 of the support electrode portion 42 is a concavely curved surface that is concavely curved around the distal end portion 13 of the discharge electrode 1 .

This modification also has the advantage that the leader discharge due to dielectric breakdown is stably generated between the needle electrode portion 41 of the counter electrode 4 and the tip portion 13 of the discharge electrode 1, and the tip portion 13 of the discharge electrode 1 There is an advantage that the electric field concentration of is further enhanced. In addition, the facing surface 420 of the supporting electrode portion 42 of the counter electrode 4 may be an appropriate flat surface, a concavely curved surface, or a surface having a shape in which these are combined.

(Third embodiment)
A discharge device according to the third embodiment will be described with reference to FIGS. 4A and 4B. Note that detailed descriptions of the same configurations as those described in the first embodiment will be omitted.

FIG. 4A shows the discharge device of this embodiment. In the discharge device of this embodiment, a limiting resistor 6 for adjusting the current peak of the leader discharge is provided in the middle of the current path 5 electrically connecting the discharge electrode 1 and the counter electrode 4 . Specifically, the limiting resistor 6 is arranged in the middle of the first conducting path 51 that electrically connects the voltage applying section 2 and the counter electrode 4 in the conducting path 5 .

In the leader discharge, an instantaneous current flows through the discharge path where the insulation is broken down, and the current resistance at that time becomes very small. current peak is suppressed. Suppressing the current peak of the instantaneous current has the advantage of suppressing the generation of NOx and the advantage of suppressing the influence of electrical noise from becoming too large. The limiting resistor 6 is not limited to being configured using a dedicated element, and any suitable configuration can be adopted as long as it has a structure having an electrical resistance as set.

FIG. 4B shows a modification of the discharge device of this embodiment. In this modification, a limiting resistor 6 is arranged in the middle of the second conducting path 52 that electrically connects the voltage applying section 2 and the discharge electrode 1 . Also in this modification, the limiting resistor 6 suppresses the peak value of the instantaneous current of the reader discharge.

(Fourth embodiment)
A discharge device according to the fourth embodiment will be described with reference to FIG. Note that detailed descriptions of the same configurations as those described in the third embodiment will be omitted.

In the discharge device of this embodiment, a capacitor 7 for adjusting the discharge frequency in the reader discharge is arranged in the middle of the conducting path 5 . The capacitor 7 is electrically connected in parallel with the voltage applying section 2 . As described above, in leader discharge, the current resistance becomes very small when instantaneous current flows. Therefore, by arranging such a capacitor 7 in the conducting path 5, the discharge frequency of the leader discharge can be effectively adjusted. be.

Capacitor 7 is not limited to one that is configured using a dedicated element, and an appropriate configuration can be adopted as long as it has a structure having a capacitance as set.

(Fifth embodiment)
A discharge device according to the fifth embodiment will be described with reference to FIG. 6A. Note that detailed descriptions of the same configurations as those described in the second embodiment will be omitted.

In the discharge device of this embodiment, as a means for stably generating a leader discharge accompanied by dielectric breakdown, instead of providing the needle-like electrode portion 41 having a sharp convex surface as in the second embodiment, Two parallel rod-like electrode portions 46 are integrally provided. The counter electrode 4 has a circular opening 43, and when viewed along the axial direction of the discharge electrode 1, two rod-shaped electrode portions 46 are positioned inside the opening 43, and the two rod-shaped electrode portions Discharge electrode 1 is located between 46 . The shortest distances between the two rod-shaped electrode portions 46 and the tip portion 13 of the discharge electrode 1 are the same. The same wording used in the text is not limited to strictly identical cases, and includes substantially identical cases.

In the discharge device of the present embodiment, leader discharge due to dielectric breakdown occurs between the tip portion 13 of the discharge electrode 1 and the portion closest to the tip portion 13 of the discharge electrode 1 among the rod-like electrode portions 46 of the counter electrode 4. can be generated stably.

(Sixth embodiment)
A discharge device according to the sixth embodiment will be described with reference to FIG. 6B. Note that detailed descriptions of the same configurations as those described in the second embodiment will be omitted.

In the discharge device of the present embodiment, as a means for stably generating the leader discharge, instead of providing the needle-like electrode portion 41, the shape of the opening edge of the opening portion 43 of the counter electrode 4 is polygonal (quadrangular). is set in The discharge electrode 1 is positioned at the center of the opening 43 when viewed along the axial direction of the discharge electrode 1 . The inner peripheral surface of the opening 43 is composed of a plurality of (four) flat surfaces continuous in the circumferential direction. The shortest distance between each flat surface and tip portion 13 of discharge electrode 1 is the same.

In the discharge device of the present embodiment, leader discharge occurs between the tip portion 13 of the discharge electrode 1 and the portion of each flat surface forming the inner peripheral surface of the opening 43 that is closest to the tip portion 13 of the discharge electrode 1. can be stably generated.

(Seventh embodiment)
A discharge device according to the seventh embodiment will be described with reference to FIG. 6C. Note that detailed descriptions of the same configurations as those described in the second embodiment will be omitted.

In the discharge device of this embodiment, as a means for stably generating a leader discharge, instead of providing the needle-shaped electrode portion 41, the shape of the opening edge of the opening portion 43 of the counter electrode 4 is provided in an elliptical shape. there is The discharge electrode 1 is positioned at the center of the opening 43 when viewed along the axial direction of the discharge electrode 1 .

In the discharge device of this embodiment, the leader discharge is stably generated between the tip portion 13 of the discharge electrode 1 and two portions of the inner peripheral surface of the opening 43 that are closest to the tip portion 13 of the discharge electrode 1. can be generated at

(Eighth embodiment)
A discharge device according to the eighth embodiment will be described with reference to FIGS. 7 to 14. FIG. Detailed descriptions of the configurations similar to those described in the second embodiment and the third embodiment will be omitted.

As shown in FIGS. 7 to 9, the discharge device of this embodiment includes a discharge electrode 1, a voltage application section 2, a liquid supply section 3 (cooling section 30), a counter electrode 4, and a current path 5. 6. The discharge electrode 1 and the counter electrode 4 are held at predetermined positions and postures by a housing 80 . The limiting resistor 6 is arranged in the middle of the first conducting path 51 that electrically connects the voltage applying section 2 and the counter electrode 4, as in the third embodiment.

The cooling unit 30 constituting the liquid supply unit 3 includes a pair of Peltier elements 301 and a pair of radiator plates 302 connected to the pair of Peltier elements 301 in a one-to-one relationship. A heat exchanger configured to cool the discharge electrode 1 . A part of each heat sink 302 is embedded in a synthetic resin housing 80, and a portion of each heat sink 302 connected to the Peltier element 301 and its peripheral portion are exposed so as to be able to dissipate heat.

Each cooling side of the pair of Peltier elements 301 is mechanically and electrically connected to the base end portion 15 of the discharge electrode 1 via solder. The heat radiating sides of the pair of Peltier elements 301 are mechanically and electrically connected to the one-to-one corresponding heat radiating plates 302 via solder. Electricity is supplied to the pair of Peltier elements 301 through the pair of radiator plates 302 and the discharge electrode 1 .

The counter electrode 4 is supported by a flat support electrode portion 42 held in a posture perpendicular to the axial direction of the discharge electrode 1 and by the support electrode portion 42 so as to be positioned closer to the discharge electrode 1 than the support electrode portion 42 is. It is provided with four needle-like electrode portions 41 . The term "orthogonal" used in the text is not limited to "orthogonal" in a strict sense, but includes "substantially orthogonal".

Each needle-like electrode portion 41 is a strip-shaped electrode portion, has a sharp tip portion 413 on one side in the longitudinal direction, and has a proximal end on the other side in the longitudinal direction (opposite side of the tip portion 413). It has a portion 415 . Each needle-like electrode portion 41 is formed so as to extend toward the center of the opening 43 from the peripheral portion of the circular opening 43 provided in the counter electrode 4 . The four needle-like electrode portions 41 extend toward each other from four portions of the peripheral portion of the opening 43 that are equally spaced in the circumferential direction. The term “equally spaced” used in the text is not limited to the case of strictly equispaced, but also includes the case of substantially evenly spaced.

As shown in FIG. 8, when viewed along the axial direction of the discharge electrode 1, the tip portions 413 of the needle-like electrode portions 41 are positioned on the same circle centered on the discharge electrode 1, and They are positioned equidistant from each other in the circumferential direction of the same circle.

As shown in FIGS. 7 and 9, each needle-like electrode portion 41 is held in a slightly inclined posture from a posture parallel to the support electrode portion 42 (a posture perpendicular to the axial direction of the discharge electrode 1). . This inclination is the inclination in the direction in which the tip portion 413 of each needle-like electrode portion 41 approaches the discharge electrode 1 . In the axial direction of the discharge electrode 1 , the distance D1 between the tip portion 413 and the discharge electrode 1 is smaller than the distance D2 between the base end portion 415 and the discharge electrode 1 .

By setting the posture of each needle-like electrode portion 41 in this way, electric field concentration is likely to occur at the tip portion 413 of each needle-like electrode portion 41. As a result, the tip portion 413 of each needle-like electrode portion 41 and the discharge There is an advantage that the leader discharge tends to occur stably between the tip portions 13 of the electrodes 1 .

Further, the counter electrode 4 includes a stepped portion 45 interposed between the support electrode portion 42 and the base end portion 415 of each needle electrode portion 41 . The stepped portion 45 constitutes the peripheral portion of the opening 43 . Each needle-like electrode portion 41 extends from the stepped portion 45 toward the center portion of the opening portion 43 . Since the step portion 45 is interposed between the support electrode portion 42 and each of the needle-like electrode portions 41, the distance D2 between the base end portion 415 and the discharge electrode 1 in the axial direction of the discharge electrode 1 is the same as the support electrode portion 42 and the discharge electrode 1. It is provided larger than the distance D3 of the electrode 1 .

By providing the counter electrode 4 with the stepped portion 45, the distal end portion 413 of the needle electrode portion 41 is prevented from protruding significantly. Therefore, when the counter electrode 4 is placed on some flat surface during transportation or assembly, the risk of deformation of the needle-shaped electrode portion 41 due to the distal end portion 413 pressing against the flat surface is reduced.

Further, each needle-like electrode portion 41 is provided with a groove portion 417 having an outer shape extending from the proximal end portion 415 toward the distal end portion 413 . The groove portion 417 is formed by bending a portion of the needle electrode portion 41 in the thickness direction of the needle electrode portion 41 . Each needle-like electrode portion 41 is provided with the groove portion 417 to increase the geometrical moment of inertia, thereby making it difficult for deformation to occur and increasing the bending strength.

The discharge device of the present embodiment described above has four needle-like electrode portions 41, and discharge caused by dielectric breakdown between the tip portion 413 of each needle-like electrode portion 41 and the tip portion 13 of the discharge electrode 1 Each path is intermittently formed to generate reader discharge. The leader discharge generated here is generated in a three-dimensionally wide area between the discharge electrode 1 and the counter electrode 4 compared to the case where only one acicular electrode portion 41 is provided. The charged fine particle liquid generated by this leader discharge is efficiently discharged to the outside through the opening 43 along the direction of the electric field formed between the four needle-like electrode portions 41 and the discharge electrode 1 .

In addition, in the discharge device of this embodiment, the tip portions 413 of the four needle-like electrode portions 41 are positioned on the same circle and are positioned equidistantly from each other in the circumferential direction of the same circle. , the generated charged fine particle liquid is more efficiently discharged to the outside through the opening 43 .

Note that the number of the needle-like electrode portions 41 is not limited to four, and a plurality of needle-like electrode portions 41 may be provided. preferable.

10A and 10B each show a modification. The modification shown in FIG. 10A is a modification in which the counter electrode 4 includes three needle-like electrode portions 41, and the modification shown in FIG. 10B is a modification in which the counter electrode 4 includes eight needle-like electrode portions 41. be. In these modified examples, the groove portion 417 and the stepped portion 45 are omitted.

In the counter electrode 4 in which the three or more needle-like electrode portions 41 are arranged in the opening 43, when viewed along the axial direction of the discharge electrode 1, the opening area of the opening 43 is equal to or greater than three needles. It is preferably set larger than the total area of the shaped electrode portion 41 . By setting the opening area in this manner, the electric field tends to concentrate on the tip portion 413 of each needle-like electrode portion 41, and the reader discharge tends to occur stably.

By the way, when the counter electrode 4 includes a plurality of needle-like electrode portions 41 as in the discharge device of the present embodiment, the strength of electric field concentration at the tip portion 413 of each needle-like electrode portion 41 should be as uniform as possible. is desirable. If the strength of the electric field concentration varies greatly, it becomes difficult to efficiently discharge the charged fine particle liquid through the opening 43 .

FIG. 11 shows a modified example in which the tip 4135 of the distal end portion 413 of each needle electrode portion 41 is rounded. The tip 4135 is a corner located at the tip when each needle-like electrode portion 41 is viewed from its thickness direction. Since the tip portion 413 of each needle-like electrode portion 41 has a rounded shape, electric field concentration is alleviated to some extent. Therefore, it is possible to prevent large variations in intensity of electric field concentration from occurring due to manufacturing variations in molding the needle-shaped electrode portions 41 .

FIGS. 12A and 12B show a modification in which the edge portion 4137 of the distal end portion 413 of each needle electrode portion 41 is chamfered. The edge portion 4137 is the edge portion of the portion near the discharge electrode 1 among the edge portions on both sides of the tip portion 413 in the thickness direction T1 (see FIG. 12B). By chamfering the edge portion 4137 of each needle-like electrode portion 41, electric field concentration is alleviated to some extent. Therefore, it is possible to prevent large variations in intensity of electric field concentration from occurring due to manufacturing variations in molding the needle-shaped electrode portions 41 .

FIG. 13 shows the main part of the mold device 9 for chamfering the end edge 4137 of each needle electrode 41 . The mold device 9 includes an upper mold 91 and a lower mold 92 for bending. When bending each needle electrode portion 41 between the upper mold 91 and the lower mold 92 , the mold device 9 bends each needle electrode on a flat surface 93 provided on the lower mold 92 side. The edges 4137 of the portion 41 are collectively crushed and chamfered. According to the mold device 9, when bending the needle-like electrode portions 41, the edge portions 4137 can be chamfered. In addition, when chamfering the needle-like electrode portions 41, the positions of the tip portions 413 (the positions of the edge portions 4137) of the needle-like electrode portions 41 are aligned. There is an advantage that the distance between the tip portion 413 and the discharge electrode 1 is made uniform.

In these modified examples, the electric field concentration at the tip portion 413 of each needle-like electrode portion 41 is alleviated, and variations in the strength of the electric field concentration are suppressed. There is also a tendency However, as described above, by setting the opening area of the opening 43 to be larger than the total area of the plurality of needle-like electrode portions 41, progress to the leader discharge is stably promoted.

FIG. 14 shows a modification in which the needle electrode portion 41 and the support electrode portion 42 of the counter electrode 4 are made of different materials. In this modification, the needle-shaped electrode portion 41 exposed to the reader discharge is made of a material having high resistance to discharge, such as titanium or tungsten, and the support electrode portion 42 has a lower discharge resistance than the needle-shaped electrode portion 41. It can be made of a material such as stainless steel. According to this modification, there is an advantage that resistance to reader discharge of the counter electrode 4 can be improved with an inexpensive structure.

(Ninth embodiment)
A discharge device of the ninth embodiment will be described with reference to FIGS. 15A to 19. FIG. Note that detailed descriptions of the same configurations as those described in the eighth embodiment will be omitted.

As shown in FIG. 15A, the limiting resistor 6 included in the discharge device of this embodiment is a high-voltage resistor 60 formed using a dedicated element. The resistor 60 includes a resistive element 601, a pair of lead wires 602 electrically and mechanically connected to the resistive element 601, and terminals electrically and mechanically connected to the ends of each lead wire 602. 603. In the high-voltage resistor 60, each lead wire 602 is generally composed of a single wire and has a property of being weak against bending (particularly a property of being weak against repeated bending). is covered with a flexible cover 605 capable of suppressing bending. Since the lead wire 602 covered with the cover 605 keeps a large radius of curvature when bent, stress concentration due to bending is alleviated.

As shown in FIGS. 15A and 15B, the discharge device of this embodiment further includes a fixing base 81 for fixing the resistor 60 . The fixed base 81 is mounted integrally with a housing 80 that supports the discharge electrode 1 and the counter electrode 4 .

A resistor element 601 and each terminal 603 are fixed at respective predetermined positions on the fixed base 81 . Thereby, each lead wire 602 is held at a predetermined position on the fixed base 81, and the risk of bending each lead wire 602 repeatedly is suppressed. A peripheral wall 811 rises from the peripheral edge of the fixed base 81 . The peripheral wall 811 surrounds at least the resistive element 601 and the pair of lead wires 602 of the resistor 60 .

As shown in FIG. 15B, the fixed base 81 can be detachably covered with a lid 82 . The resistive element 601 and the pair of lead wires 602 are covered with a peripheral wall 811 and a lid 82 so that they cannot be touched from the outside.

FIGS. 16 and 17 respectively show modifications in which the resistor 60 is installed without the fixing base 81 as shown in FIGS. 15A and 15B. In the modified example of FIG. 16, one lead wire 602 of the resistor 60 is electrically and mechanically directly connected to the opposing electrode 4 .

17, a resistor 60 is electrically and mechanically directly connected to the opposing electrode 4, and the resistor 60 is fixed to the outer surface of the housing 80. In the modification of FIG. In this modified example, the back side of the housing 80 (the side opposite to the side where the counter electrode 4 is located) also serves as a fixing base 81 .

16 and 17 are examples in which the limiting resistor 6 is directly attached to the opposing electrode 4, in other words, an example in which the length of the wiring between the opposing electrode 4 and the limiting resistor 6 is set to 0 mm. is. When the limiting resistor 6 is arranged in the first conducting path 51, the length of the wiring between the opposing electrode 4 and the limiting resistor 6 is preferably set within the range of 0 to 30 mm. This is because the current resistance becomes very small when instantaneous current flows through the discharge path where insulation is broken down. This is because the discharge becomes unstable due to the influence of

From the measurement results shown in the graph of FIG. 18A, it is confirmed that when the length of the wiring between the counter electrode 4 and the limiting resistor 6 exceeds 30 mm, the amount of active ingredients (radical amount) generated by the leader discharge decreases. be done. Although the vertical axis of FIG. 18A does not show numerical values, the upper limit of the amount of generated radicals is about 5 trillion/sec.

Further, when the limiting resistor 6 is arranged in the first conducting path 51, the length between the voltage applying section 2 and the limiting resistor 6 in the first conducting path 51 may be set within the range of 0 to 200 mm. preferable. This is because the current resistance becomes very small when an instantaneous current flows, so if the length of the wiring between the voltage applying section 2 and the limiting resistor 6 exceeds 200 mm, the stray capacitance of the wiring prevents discharge. This is because it stabilizes.

The measurement results shown in the graph of FIG. 18B also show that when the length of the wiring between the applying electrode section 2 and the limiting resistor 6 exceeds 200 mm, the amount of active ingredients (the amount of radicals) generated by the leader discharge decreases. It is confirmed. Also in FIG. 18B, the upper limit of the amount of generated radicals is about 5 trillion/sec.

The measurement results shown in the graphs of FIGS. 18A and 18B were obtained using the apparatus shown schematically in FIG. In this device, the limiting resistor 6 is arranged in the wiring that electrically connects the counter electrode 4 and the voltage applying section 2, and a metal plate 89 serving as a ground is placed at a distance D4 (=4 mm) from the limiting resistor 6. A high voltage of 7.0 kV was applied to a discharge electrode (not shown), and the amount of radicals generated by the leader discharge was measured.

The above results are obtained when the limiting resistor 6 is arranged in the first conducting path 51. However, when the limiting resistor 6 is arranged in the second conducting path 52 electrically connecting the discharge electrode 1 and the voltage applying section 2, (see FIG. 4B), similar results are obtained.

In other words, when the limiting resistor 6 is arranged in the second conducting path 52, setting the length between the discharge electrode 1 and the limiting resistor 6 in the second conducting path 52 within 30 mm stabilizes the leader discharge. It is preferable to cause Moreover, it is preferable to set the length between the voltage applying portion 2 and the limiting resistor 6 in the second conducting path 52 within 200 mm in order to stably generate the reader discharge.

(Tenth embodiment)
A discharge device according to the tenth embodiment will be described with reference to FIGS. 20 to 22. FIG. Note that detailed descriptions of the same configurations as those described in the eighth embodiment will be omitted.

FIG. 20 is a plan view showing a main part of the discharge device of this embodiment. 21 is a sectional view taken along line aa of FIG. 20, and FIG. 22 is a sectional view taken along line bb of FIG.

In FIG. 20, the discharge electrode 1, the counter electrode 4, the pair of Peltier elements 301, etc. are omitted. In the discharge device of the present embodiment, of the exposed portion (the portion not buried in the housing 80) of each heat sink 302, the corner portion is chamfered in the peripheral region of the portion 3025 where the Peltier element 301 is mounted. ing. Specifically, the portion indicated by arrow C in FIGS. 20 to 22 is chamfered. A stage-like portion 3025 on which the Peltier element 301 is mounted is not chamfered.

The chamfering of each heat sink 302 is such that when each heat sink 302 is dipped in a coating agent such as a resin (for example, a urethane-based ultraviolet curable resin), the corners of each heat sink 302 can be secured more reliably by this coating. to cover it. This is because each radiator plate 302 is manufactured by punching a sheet metal, so that after punching, a corner portion that is substantially perpendicular to the edge is formed. If each radiator plate 302 has a substantially right-angled corner portion, it is difficult to form a coating with a sufficient thickness at the corner portion, and the corner portion of each radiator plate 302 is likely to be exposed.

In the discharge device of this embodiment, the leader discharge with higher energy than the corona discharge is generated, so the acidity of the liquid 35 (condensed water) supplied to the discharge electrode 1 tends to be strengthened. Therefore, when a part of each heat sink 302 is exposed from the coating, the part is oxidized (corroded) and the durability is lowered.

As another countermeasure against this, it is conceivable to reduce the exposure by setting the film thickness of the coating to be large as a whole. However, since the coating is applied so as to cover the entire area from the cooling side to the heat radiation side of each heat sink 302 and the Peltier element 301 mounted thereon, if the thickness of the coating increases as a whole, the Peltier element 301 may be damaged. Cooling performance will decline. According to the discharge device of this embodiment, it is possible to suppress the deterioration of each heat sink 302 and the solder while suppressing the film thickness of the coating.

(Eleventh embodiment)
A discharge device of the eleventh embodiment will be described with reference to FIGS. 23 and 24. FIG. Detailed descriptions of the same configurations as those described in the eighth embodiment will be omitted.

In the discharge device of this embodiment, in order to adjust the discharge frequency (the frequency of instantaneous current) in the reader discharge, the capacitor is fed back to the low voltage side instead of arranging the capacitor on the high voltage side as in the discharge device of the fourth embodiment. A time control unit 85 is arranged.

FIG. 23 is a block diagram showing the essential parts of the discharge device of this embodiment. As shown in FIG. 23, in the discharge device of the present embodiment, in addition to the high voltage generation circuit 20 that constitutes the voltage application section 2, a voltage control section 83, a current control section 84, a feedback time control section 85, and a high voltage drive circuit 86 are provided. and an input unit 87 .

When power is supplied to the input section 87 , the high voltage drive circuit 86 operates and the high voltage is output from the high voltage generation circuit 20 . When a control signal related to this output is input to the voltage control section 83 and the current control section 84, the voltage control section 83 and the current control section 84 control the voltage and current to predetermined values via the feedback time control section 85. generate a control signal for Based on this control signal, the high-voltage drive circuit 86 raises the output voltage up to a predetermined discharge voltage, and when the output voltage drops due to discharge accompanied by dielectric breakdown, the output voltage is raised again to the predetermined discharge voltage. Repeat the work of letting This causes reader discharge.

In the discharge device of this embodiment, the feedback time control section 85 can control the feedback time from when the output voltage drops to when it returns to the predetermined discharge voltage. By controlling the feedback time, the discharge frequency of the reader discharge is adjusted.

FIG. 24 shows a modification of the discharge device of this embodiment. In this modification, the high-voltage drive circuit 86 includes a microcomputer 861 and a peripheral circuit section 862 , and the microcomputer 861 constitutes the feedback time control section 85 . Furthermore, the microcomputer 861 can be configured to serve as at least one of the voltage control section 83 and the current control section 84 .

In the discharge device of this embodiment, the discharge frequency of the leader discharge can be adjusted by the feedback time control unit 85 arranged on the low voltage side. Therefore, there is an advantage that the adjustment range of the discharge characteristics is wide, and the number of members on the high voltage side increases. It has the advantage of being less expensive and, as a result, less expensive.

INDUSTRIAL APPLICABILITY As described above, the discharge device according to the present invention generates effective components by means of leader discharge and can suppress the increase of ozone, so it can be used in refrigerators, washing machines, dryers, air conditioners, fans, air cleaners, humidifiers, It can be applied to various uses such as a device, a facial device, and an automobile.

Reference Signs List 1 discharge electrode 13 tip portion 15 base portion 2 voltage application portion 3 liquid supply portion 35 liquid 4 counter electrode 41 needle electrode portion 410 convex surface 413 tip portion 415 base portion 417 groove portion 42 support electrode portion 420 counter surface 43 opening portion 45 Stepped portion 5 Electric path 51 First electric path 52 Second electric path 6 Limiting resistor 7 Capacitor 9 Mold device 91 Upper mold 92 Lower mold 9 Mold device 93 One surface T1 Thickness direction D1 Tip of needle electrode and discharge electrode Distance between D2 Distance between the base end portion of the needle-like electrode portion and the discharge electrode D3 Distance between the support electrode portion and the discharge electrode

Claims (17)

a discharge electrode;
a voltage applying unit that applies a voltage to the discharge electrode and causes the discharge electrode to generate a discharge further developed from the corona discharge;
The discharge is
It is a discharge that intermittently generates a discharge path extending from the discharge electrode to the surroundings due to dielectric breakdown, and is characterized by being a discharge in which an instantaneous current flows 2 to 10 times as much as that of corona discharge. Device. further comprising a liquid supply unit that supplies liquid to the discharge electrode;
The discharge device according to claim 1, wherein the discharge electrostatically atomizes the liquid supplied to the discharge electrode. further comprising a counter electrode positioned opposite the discharge electrode;
The discharge is
3. The discharge device according to claim 1, wherein the discharge intermittently generates a discharge path between the discharge electrode and the counter electrode, the discharge path being dielectrically broken so as to connect the two. 4. The discharge device according to claim 3, wherein the counter electrode includes a needle-like electrode portion facing the discharge electrode. the needle-shaped electrode portion has a distal end portion and a proximal end portion on opposite sides;
the discharge electrode has an axial direction;
5. The discharge device according to claim 4, wherein the distance between the tip end portion and the discharge electrode in the axial direction is smaller than the distance between the base end portion and the discharge electrode in the axial direction. The counter electrode is
a supporting electrode portion held in a posture orthogonal to the axial direction;
further comprising a step portion interposed between the supporting electrode portion and the needle-like electrode portion;
The discharge device according to claim 5, wherein the distance between the base end portion and the discharge electrode in the axial direction is greater than the distance between the support electrode portion and the discharge electrode in the axial direction. the needle-like electrode portion has a groove for suppressing deformation of the needle-like electrode portion;
The discharge device according to any one of claims 4 to 6, wherein the groove is formed by bending a part of the needle electrode portion in a thickness direction of the needle electrode portion. . The counter electrode further comprises a support electrode section that supports the needle-shaped electrode section,
The discharge device according to claim 4, wherein the needle electrode portion and the support electrode portion are members made of different materials. The discharge device according to any one of claims 4 to 8, wherein the opposing electrode includes a plurality of the needle-like electrode portions. 10. The discharge device according to claim 9, wherein tip portions of the plurality of needle-like electrode portions are positioned on the same circle. 11. The discharge device according to claim 10, wherein tip portions of the plurality of needle-like electrode portions are positioned equidistantly from each other in the circumferential direction of the same circle. The discharge device according to any one of claims 9 to 11, wherein each of said plurality of needle-like electrode portions has a rounded tip portion. each of the plurality of needle-shaped electrode portions is a piece-shaped electrode portion having a thickness,
13. The method according to any one of claims 9 to 12, wherein, of edge portions in the thickness direction of each of the plurality of needle-like electrode portions, portions near the discharge electrode are chamfered. Discharge device as described. The discharge device according to any one of claims 9 to 13, wherein the plurality of needle-like electrode portions are three or more needle-like electrode portions positioned apart from each other. The counter electrode is
further comprising an opening in which the three or more needle-like electrode portions are arranged;
15. The discharge device according to claim 14, wherein the opening area of the opening is larger than the total area of the three or more acicular electrode parts. The counter electrode is
at least one sharp convex surface facing the discharge electrode;
A facing surface facing the discharge electrode,
4. The discharge device according to claim 3, wherein the facing surface has a flat surface, a concave curved surface, or a shape in which these are combined. The discharge device according to any one of claims 1 to 16, further comprising a capacitor electrically connected in parallel with the voltage application section.

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