JP7442109B2 - discharge device - Google Patents

Description

The present invention relates to a discharge device, and more particularly to a discharge device that includes a discharge electrode and a voltage application section that applies a voltage to the discharge electrode.

Conventionally, a discharge device including a discharge electrode and a voltage application section has been provided. As a discharge device, there is a device that applies a voltage to the discharge electrode using a voltage application part and causes a corona discharge at the discharge electrode to generate air ions, or a device that supplies liquid to the discharge electrode and then uses the discharge electrode to generate corona discharge. An apparatus for generating a charged fine particle liquid containing radicals is known (for example, see Patent Document 1).

JP2011-67738A

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

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

In order to solve the above problems, a discharge device of the present invention includes a discharge electrode, a voltage application section that applies a voltage to the discharge electrode to cause discharge to occur in the discharge electrode, and a voltage application section that receives the output of the voltage application section. A voltage control unit and a current control unit that generate control signals for controlling the voltage and current to predetermined values, and based on the control signals, increase the output voltage to a predetermined discharge voltage, causing dielectric breakdown. When discharge occurs and the output voltage drops, the high voltage drive circuit repeatedly increases the output voltage to the predetermined discharge voltage, and controls the feedback time from when the output voltage drops until it returns to the predetermined discharge voltage. and a feedback time control section.

The discharge device of the present invention has the effect of being able to increase the amount of active ingredients produced and suppressing the increase in ozone at this time.

FIG. 1 is a schematic diagram showing a discharge device according to a first embodiment. FIG. 2A is a graph diagram schematically showing a current flowing in a corona discharge, and FIG. 2B is a graph diagram schematically showing a current flowing in a leader discharge. FIG. 3A is a schematic diagram showing a discharge device of the second embodiment, and FIG. 3B is a schematic diagram showing a modification of the discharge device. FIG. 4A is a schematic diagram showing a discharge device of the third embodiment, and FIG. 4B is a schematic diagram showing a modification of the discharge device. FIG. 5 is a schematic diagram showing a discharge device according to a fourth embodiment. FIG. 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 perspective view showing a main part of a discharge device according to a seventh embodiment. FIG. 2 is a perspective view showing the main parts of the discharge device of FIG. FIG. 7 is a perspective view showing a discharge device according to an eighth embodiment. FIG. 8 is a plan view showing the discharge device same as the above. FIG. 9 is a side sectional view showing the discharge device same as the above. FIG. 10A is a plan view showing a modification of the discharge device as described above, and FIG. 10B is a plan view showing another modification of the discharge device as described above. FIG. 11 is a plan view showing a main part of another modified example of the above discharge device. FIG. 12A is a side view showing a main part of another modified example of the discharge device same as the above, and FIG. 12B is an enlarged view of section A in FIG. 12A. FIG. 13 is a cross-sectional view showing a process of forming the modified needle-like electrode portion shown in FIGS. 12A and 12B. FIG. 14 is a perspective view showing a main part of another modified example 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 the case where the above discharge device is provided with a lid. FIG. 16 is a perspective view showing a modification of the above discharge device. FIG. 17 is a perspective view showing another modification of the above discharge device. FIG. 18A is a graph diagram showing the relationship between the wiring length between the counter electrode and the resistor and the amount of active ingredient, and FIG. 18B is a graph diagram showing the relationship between the wiring length between the voltage application part and the resistor and the amount of active ingredient. . FIG. 19 is a schematic diagram showing an apparatus that performed the measurements shown in the graphs of FIGS. 18A and 18B. It is a top view which shows the principal part of the discharge device of 10th Embodiment. 21 is a sectional view taken along line a-a in FIG. 20. FIG. 21 is a sectional view taken along line bb in FIG. 20. FIG. FIG. 23 is a block diagram showing the main parts of the discharge device according to the eleventh embodiment. FIG. 24 is a block diagram showing main parts of a modified example of the discharge device same as the above.

A first invention is a discharge device that includes a discharge electrode and a voltage application section that applies a voltage to the discharge electrode and causes the discharge electrode to generate a discharge that is further developed from a corona discharge. The discharge is a discharge that intermittently generates a dielectrically broken discharge path extending from the discharge electrode to the surrounding area. Thereby, the amount of active ingredients produced can be increased, and at the same time, an increase in ozone can be suppressed.

A second aspect of the present invention is particularly based on the first aspect, further comprising a liquid supply section that supplies liquid to the discharge electrode. The liquid supplied to the discharge electrode is electrostatically atomized by the discharge. Thereby, it is possible to increase the amount of charged fine particle liquid produced, and at the same time, it is possible to suppress an increase in ozone.

In a third aspect of the present invention, particularly in the first or second aspect of the present invention, the discharge electrode further includes a counter electrode located opposite to the discharge electrode. The discharge intermittently generates a dielectrically broken discharge path between the discharge electrode and the counter electrode so as to connect the two. Thereby, a discharge that intermittently generates a dielectrically broken discharge path can be stably generated between the discharge electrode and the counter electrode.

In a fourth aspect, particularly in the third aspect, the opposing electrode includes a needle-shaped electrode portion facing the discharge electrode. Thereby, a discharge that intermittently generates a dielectrically broken discharge path can be stably generated between the discharge electrode and the needle-like electrode portion.

In a fifth invention, particularly in the fourth invention, 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, and the discharge electrode has an axial direction, and The distance between the tip end portion and the discharge electrode is smaller than the distance between the base end portion and the discharge electrode in the axial direction. Thereby, a discharge that intermittently generates a dielectrically broken discharge path can be stably generated between the discharge electrode and the needle-like electrode portion.

In a sixth invention, particularly in the fifth invention, the counter electrode is interposed between a supporting electrode part held in a posture perpendicular to the axial direction, and the supporting electrode part and the needle-shaped electrode part. It further includes a stepped portion. A distance between the base end portion and the discharge electrode in the axial direction is greater than a distance between the support electrode portion and the discharge electrode in the axial direction. Thereby, it is possible to suppress the tip portion of the needle-like electrode portion from protruding greatly and to suppress deformation of the needle-like electrode portion.

In a seventh invention, particularly in any one of the fourth to sixth inventions, the needle-like electrode part has a groove part for suppressing deformation of the needle-like electrode part, and the groove part is arranged in the needle-like electrode part. A part of the needle-shaped electrode part is formed by bending in the thickness direction of the needle-shaped electrode part. Thereby, it is possible to increase the moment of inertia of the acicular electrode portion and suppress deformation of the acicular electrode portion.

In an eighth invention, particularly in the fourth invention, the counter electrode further includes a support electrode part that supports the needle electrode part, and the needle electrode part and the support electrode part are made of different materials. It is a member. Thereby, it is possible to increase the resistance of the needle-shaped electrode portion to leader discharge while suppressing an increase in cost.

In a ninth invention, particularly in any one of the fourth to eighth inventions, the opposing electrode includes a plurality of the needle-like electrode parts. As a result, the produced active ingredients are efficiently released to the outside.

In a tenth invention, particularly in the ninth invention, the tip portions of each of the plurality of needle-like electrode portions are located on the same circle. This allows the produced active ingredient to be released to the outside more efficiently.

In an eleventh invention, particularly in the tenth invention, the tip portions of each of the plurality of needle-like electrode portions are located at equal distances from each other in the circumferential direction of the same circle. This allows the produced active ingredient to be released to the outside more efficiently.

In a twelfth invention, particularly in any one of the ninth to eleventh inventions, each of the plurality of needle-shaped electrode portions has a rounded tip portion. This prevents large variations in the intensity of electric field concentration from occurring due to manufacturing variations in the plurality of needle-like electrode parts.

In a thirteenth invention, in particular, in any one of the ninth to twelfth inventions, each of the plurality of needle-like electrode parts is a thick strip-shaped electrode part, and each of the plurality of needle-like electrode parts is A portion of the edge portion in the thickness direction near the discharge electrode is chamfered. This prevents large variations in the intensity of electric field concentration from occurring due to manufacturing variations in the plurality of needle-like electrode parts.

In a fourteenth invention, particularly in any one of the ninth to thirteenth inventions, the plurality of needle-like electrode parts are three or more needle-like electrode parts located apart from each other. This allows the produced active ingredient to be released to the outside more efficiently.

In a fifteenth invention, particularly in the fourteenth invention, the counter electrode further includes an opening in which the three or more needle-like electrode parts are arranged, and the opening area of the opening is larger than the three or more needle-like electrode parts. is larger than the total area of the needle-like electrode portion. This facilitates the progression from corona discharge to leader discharge.

In a sixteenth aspect, particularly in the third aspect, the opposing electrode includes at least one sharp convex surface facing the discharge electrode, and an opposing surface facing the discharge electrode, and the opposing surface includes: It has a flat surface, a concave curved surface, or a combination thereof. Thereby, electric field concentration tends to occur at the tip portion of the discharge electrode.

A seventeenth invention, particularly in any one of the first to sixteenth inventions, further includes a capacitor electrically connected in parallel to the voltage application section. Thereby, the discharge frequency of the leader discharge can be adjusted.

In an 18th invention, in particular, in the method for manufacturing a discharge device according to the 13th invention, the edge portions in the thickness direction of each of the plurality of needle electrode portions are crushed at one time on one surface of a mold device. The above-mentioned chamfering is performed by. Thereby, the positions of the tip portions of the plurality of needle-shaped electrode portions are aligned at once.

Embodiments of the present invention will be described below with reference to the drawings. Note that the present invention is not limited to the embodiments described below, and the configurations of the embodiments described below can be combined as appropriate.

(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 a current supply path 5.

The discharge electrode 1 is an elongated needle-like electrode. The discharge electrode 1 has a distal end portion 13 at one end in the axial direction, and a base end portion 15 at the other end in the axial direction (opposite to the distal end portion 13). The term "acicular" used in this text is not limited to those with a sharp tip, but also includes those with a rounded tip.

The voltage application section 2 is electrically connected to the discharge electrode 1 so as to apply a high voltage of about 7.0 kV to the discharge electrode 1. The discharge device of this embodiment includes a counter electrode 4, and the voltage application 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 a means for supplying a liquid 35 for electrostatic atomization to the discharge electrode 1, and in the discharge device of this embodiment, the cooling unit 30 cools the discharge electrode 1 and generates dew condensation water. The liquid supply section 3 is configured by: The cooling unit 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 that the liquid supply unit 3 supplies to the discharge electrode 1 is dew condensation water that occurs on the discharge electrode 1 .

The counter electrode 4 is located opposite 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 the counter electrode 4 in the thickness direction. The opening 43 is provided in a region of the opposing electrode 4 that is closest to the tip portion 13 of the discharge electrode 1 . The penetrating direction of the opening 43 and the axial direction of the discharge electrode 1 are parallel to each other. The term "parallel" used in this 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 disposed in the middle thereof. That is, the energization path 5 includes a first energization path 51 that electrically connects the voltage application section 2 and the counter electrode 4, and a second energization path 52 that electrically connects the voltage application section 2 and the discharge electrode 1.

In the discharge device of this embodiment, a high voltage of about 7.0 kV is applied between the discharge electrode 1 and the counter electrode 4 by the voltage application unit 2 while the liquid 35 is held in the discharge electrode 1 . As a result, 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 in the tip portion 13), and this corona discharge is further converted into a high-energy discharge. progress to. This high-energy discharge is a type of discharge in which a dielectrically broken (total broken) discharge path extending from the discharge electrode 1 to the surrounding area occurs intermittently. In the discharge device of this embodiment, a dielectrically broken discharge path that connects the discharge electrode 1 and the counter electrode 4 is generated intermittently (in a pulsed manner). This type of discharge is called a "leader discharge."

In leader discharge, an instantaneous current about 2 to 10 times that in corona discharge flows through a discharge path broken down between discharge electrode 1 and counter electrode 4. FIG. 2A schematically shows a current flowing in a corona discharge, and FIG. 2B schematically shows a current flowing in a leader discharge developed from a 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 in corona discharge is generated.

When radicals are generated by leader discharge, ozone is also generated. However, in leader discharge, about 2 to 10 times more radicals are generated than in corona discharge, whereas the amount of ozone generated is suppressed to the same level as in corona discharge. In other words, by further developing corona discharge and generating leader discharge, the amount of ozone generated relative to the amount of radicals generated can be significantly suppressed. This is thought to be because when the generated ozone is released while being exposed to the leader discharge, a portion of the ozone is destroyed by the high-energy leader discharge.

Here, leader discharge will be further explained.

Generally, when energy is applied between a pair of electrodes to generate a discharge, the form of the discharge progresses to corona discharge, glow discharge, and arc discharge depending on the amount of input energy.

Corona discharge is a discharge that occurs locally 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 a pair of electrodes, and as long as energy is applied, a discharge path with dielectric breakdown continues to exist.

In contrast, leader discharge is accompanied by dielectric breakdown between a pair of electrodes, but the dielectric breakdown does not exist continuously but occurs intermittently.

In the discharge device of this embodiment, the electrical capacity (capacity of electricity that can be released per unit time) of the voltage application section 2 is adjusted so that this type of leader discharge occurs between the discharge electrode 1 and the counter electrode 4. is set. In other words, in the discharge device of this embodiment, when corona discharge progresses to dielectric breakdown, a large instantaneous current flows through the dielectrically broken discharge path, but immediately after that, the voltage drops and the discharge stops, and then The electrical capacity of the voltage application section 2 is set so that the voltage increases and dielectric breakdown occurs repeatedly. This capacitance setting realizes a leader discharge in which instantaneous dielectric breakdown and discharge stop are alternately repeated, rather than continuous dielectric breakdown as in glow discharge or arc discharge.

As an example currently confirmed, the discharge frequency (frequency of instantaneous current) in leader 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 it repeats instantaneous discharge (high energy state) and discharge stop (low energy state).

In the discharge device of this embodiment, the liquid 35 is supplied to the discharge electrode 1 by the 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. 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 larger amount of radicals than 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.

The discharge device of this embodiment described above based on FIG. It is also possible to configure the system without it. In this case, air ions are generated by the leader discharge that occurs between the discharge electrode 1 and the counter electrode 4.

Moreover, although the discharge device of this embodiment is equipped with the counter electrode 4, it is also possible to configure it without 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, a charged fine particle liquid is generated by the leader discharge. In the discharge device of this embodiment, it is also possible not to include both the liquid supply section 3 and the counter electrode 4. In this case, if a leader discharge is caused between the discharge electrode 1 and some member around the discharge electrode 1, air ions are generated by the leader discharge.

(Second embodiment)
The discharge device of the second embodiment will be described based on FIGS. 3A and 3B. Note that detailed explanations of configurations similar to 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 is different from the first embodiment in that the counter electrode 4 integrally includes a needle-like electrode section 41 and a supporting electrode section 42 that supports the needle-like electrode section 41 .

The needle-like electrode portion 41 is an electrode portion that protrudes from the opposing surface 420 of the support electrode portion 42 that faces the discharge electrode 1 toward the side that approaches the discharge electrode 1 . The needle electrode portion 41 has a sharp convex surface. Of the entire counter electrode 4, the tip of the needle-like electrode portion 41 is located closest to the discharge electrode 1. The needle-like electrode portion 41 is located near the opening 43 that the counter electrode 4 has. Although the discharge device of this embodiment includes one needle-like electrode section 41, it is also possible to include a plurality of needle-like electrode sections 41.

The supporting electrode section 42 includes a flat electrode section 421 having a flat opposing surface and a dome-shaped electrode section 422 having a concave opposing surface. The opposing surfaces of the electrode section 421 and the electrode section 422 constitute the opposing surface 420 of the supporting electrode section 42 . The opposing surface 420 of the supporting electrode section 42 has a shape that is a combination of a flat surface and a concave curved surface.

Since the discharge device of this embodiment has the above configuration, electric field concentration occurs between the needle-shaped 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 in the tip portion 13). , leader discharge occurs stably between the needle-like electrode portion 41 of the counter electrode 4 and the tip portion 13 of the discharge electrode 1 due to dielectric breakdown. In addition, the opposing surface 420 of the supporting electrode portion 42 further increases 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 modification, the support electrode section 42 is comprised of a dome-shaped electrode section 423 having a concave opposing surface. The opposing surface 420 of the supporting electrode portion 42 is a concave curved surface that is concavely curved around the tip portion 13 of the discharge electrode 1 .

This modification also has the advantage that leader discharge occurs stably due to dielectric breakdown between the needle-shaped electrode part 41 of the counter electrode 4 and the tip part 13 of the discharge electrode 1, and This has the advantage that electric field concentration can be further increased. Note that the opposing surface 420 of the supporting electrode portion 42 of the opposing electrode 4 may be any suitable flat surface, concave curved surface, or a combination thereof.

(Third embodiment)
A discharge device of a third embodiment will be described based on FIGS. 4A and 4B. Note that detailed explanations of configurations similar to 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 leader discharge is provided in the middle of a current-carrying path 5 that electrically connects the discharge electrode 1 and the counter electrode 4. Specifically, a limiting resistor 6 is disposed in the middle of a first current conducting path 51 that electrically connects the voltage applying section 2 and the counter electrode 4 in the current conducting path 5 .

In leader discharge, an instantaneous current flows through a dielectrically broken discharge path, and the current resistance at that time becomes very small. Therefore, in the discharge device of this embodiment, a limiting resistor 6 is provided in the first current-carrying path 51 to control the instantaneous current. This suppresses the current peak. 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 constructed using a dedicated element, and may have any suitable structure as long as it has a set electrical resistance.

FIG. 4B shows a modification of the discharge device of this embodiment. In this modification, a limiting resistor 6 is disposed in the middle of a second energizing path 52 that electrically connects the voltage application section 2 and the discharge electrode 1. Also in this modification, the peak value of the instantaneous current of the leader discharge is suppressed by the limiting resistor 6.

(Fourth embodiment)
A discharge device according to a fourth embodiment will be described based on FIG. 5. Note that detailed explanations of configurations similar to those described in the third embodiment will be omitted.

In the discharge device of this embodiment, a capacitor 7 is disposed in the middle of the energizing path 5 to adjust the discharge frequency in leader discharge. Capacitor 7 is electrically connected in parallel to voltage application section 2 . As mentioned above, in leader discharge, the current resistance when instantaneous current flows becomes very small, so by arranging such a capacitor 7 in the current carrying path 5, the discharge frequency of leader discharge can be effectively adjusted. Ru.

The capacitor 7 is not limited to one constructed using a dedicated element, and may have any suitable structure as long as it has a set capacitance.

(Fifth embodiment)
A discharge device according to a fifth embodiment will be described based on FIG. 6A. Note that detailed explanations of configurations similar to those described in the second embodiment will be omitted.

In the discharge device of this embodiment, as a means for stably generating 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-shaped 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 parts 46 are located inside the opening 43, and two rod-shaped electrode parts 46 are located inside the opening 43. Discharge electrode 1 is located between 46. The shortest distance between the two rod-shaped electrode parts 46 and the tip part 13 of the discharge electrode 1 is the same. The same words used in the text are not limited to strictly the same, but include substantially the same.

In the discharge device of this embodiment, leader discharge due to dielectric breakdown occurs between the portion of each rod-shaped electrode portion 46 of the counter electrode 4 that is closest to the tip portion 13 of the discharge electrode 1 and the tip portion 13 of the discharge electrode 1. It can be generated stably.

(Sixth embodiment)
A discharge device according to the sixth embodiment will be described based on FIG. 6B. Note that detailed explanations of configurations similar to those described in the second embodiment will be omitted.

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

In the discharge device of this embodiment, a leader discharge is generated 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 flat surfaces forming the inner peripheral surface of the opening 43. can be generated stably.

(Seventh embodiment)
The discharge device of the seventh embodiment will be described based on FIG. 6C. Note that detailed explanations of configurations similar to those described in the second embodiment will be omitted.

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

In the discharge device of this embodiment, leader discharge is stably performed 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.

(Eighth embodiment)
The discharge device of the eighth embodiment will be explained based on FIGS. 7 to 14. Note that detailed explanations of 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 conduction path 5, and further includes a limiting resistor. It is equipped with 6. The discharge electrode 1 and the counter electrode 4 are held at predetermined positions and postures by a housing 80. As in the third embodiment, the limiting resistor 6 is disposed in the middle of the first energizing path 51 that electrically connects the voltage applying section 2 and the counter electrode 4.

The cooling unit 30 constituting the liquid supply unit 3 includes a pair of Peltier elements 301 and a pair of heat sinks 302 connected one-to-one to the pair of Peltier elements 301. This is a heat exchanger configured to cool the discharge electrode 1. A portion of each heat sink 302 is embedded in the synthetic resin casing 80, and a portion of each heat sink 302 connected to the Peltier element 301 and a surrounding portion thereof are exposed to enable heat radiation.

The cooling side of each 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 radiation side of each of the pair of Peltier elements 301 is mechanically and electrically connected to the corresponding heat radiation plate 302 via solder. The pair of Peltier elements 301 are energized through the pair of heat sinks 302 and the discharge electrode 1.

The counter electrode 4 is supported by a flat support electrode part 42 held in a posture perpendicular to the axial direction of the discharge electrode 1 and by the support electrode part 42 so as to be located closer to the discharge electrode 1 than the support electrode part 42. It has four needle-like electrode parts 41. The word orthogonal used in this text is not limited to orthogonal in a strict sense, but includes substantially orthogonal.

Each needle-like electrode part 41 is an elongated piece-like electrode part, and has a sharp tip part 413 on one side in the longitudinal direction, and a proximal end on the other side in the longitudinal direction (opposite side of the tip part 413). It has a portion 415. Each needle-shaped electrode portion 41 is formed to extend from the periphery of the circular opening 43 of the counter electrode 4 toward the center of the opening 43 . The four needle-shaped electrode portions 41 extend from four portions of the peripheral edge of the opening 43 that are equally spaced apart in the circumferential direction in a direction toward each other. The words "evenly spaced" used in this text are not limited to strictly evenly spaced, but include substantially equally spaced.

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

As shown in FIGS. 7 and 9, each needle electrode part 41 is held in a slightly inclined position from a position parallel to the supporting electrode part 42 (a position perpendicular to the axial direction of the discharge electrode 1). . This inclination is a 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 distal end 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 part 41 in this way, electric field concentration tends to occur at the tip part 413 of each needle-like electrode part 41, and as a result, the distal end part 413 of each needle-like electrode part 41 and discharge There is an advantage that leader discharge is more likely 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 supporting electrode portion 42 and the base end portion 415 of each needle electrode portion 41. The step portion 45 constitutes a peripheral portion of the opening portion 43 . Each needle-like electrode portion 41 extends from the stepped portion 45 toward the center of the opening 43 . Since the step portion 45 is interposed between the supporting electrode portion 42 and each needle electrode portion 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 distance D3 between the electrodes 1 and 1 is greater than the distance D3 between the electrodes 1.

By providing the counter electrode 4 with the stepped portion 45, the tip portion 413 of the needle electrode portion 41 is prevented from protruding greatly. Therefore, when the counter electrode 4 is placed on some plane during transportation or assembly, the risk that the tip portion 413 will be pressed against the plane and the needle-like electrode part 41 will be deformed is reduced.

Further, each needle-shaped electrode portion 41 is provided with a groove portion 417 having an outer shape extending from the base end portion 415 toward the distal end portion 413. The groove portion 417 is formed by pressing and bending a part of the needle electrode portion 41 in the thickness direction of the needle electrode portion 41 . Each acicular electrode portion 41 has a groove portion 417, thereby increasing the moment of inertia of the area, thereby making deformation less likely to occur and increasing bending strength.

The discharge device of the present embodiment described above is provided with four needle-shaped electrode parts 41, and a discharge caused by dielectric breakdown between the tip part 413 of each needle-shaped electrode part 41 and the tip part 13 of the discharge electrode 1 is provided. Each path is formed intermittently to generate a leader discharge. The leader discharge that occurs here occurs in a three-dimensionally wider area between the discharge electrode 1 and the counter electrode 4, compared to the case where there is only one needle-like electrode portion 41. 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-shaped electrode parts 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 located on the same circle and are spaced from each other at equal distances 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 needle-like electrode parts 41 is not limited to four, and may be a plurality, but in order to efficiently discharge the charged fine particle liquid to the outside, the number of needle-like electrode parts 41 should be three or more. preferable.

Modifications are shown in FIGS. 10A and 10B, respectively. The modification shown in FIG. 10A is a modification in which the counter electrode 4 has three needle-like electrode parts 41, and the modification shown in FIG. 10B is a modification in which the counter electrode 4 has eight needle-like electrode parts 41. be. In these modifications, the groove portion 417 and the stepped portion 45 are omitted.

In the counter electrode 4 in which three or more needle-like electrode parts 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 the same as that of the three or more needles. It is preferable that the area is set larger than the total area of the shaped electrode portion 41. If the opening area is set in this manner, the electric field is likely to concentrate on the tip portion 413 of each needle-shaped electrode portion 41, and leader discharge is likely to occur stably.

By the way, when the counter electrode 4 includes a plurality of needle-like electrode parts 41 as in the discharge device of this embodiment, the intensity of electric field concentration at the tip portion 413 of each needle-like electrode part 41 is as uniform as possible. This is desirable. If large variations occur in the intensity of electric field concentration, it becomes difficult for the charged fine particle liquid to be efficiently discharged through the opening 43.

FIG. 11 shows a modified example in which the tip end 4135 of the tip portion 413 of each needle electrode portion 41 is rounded. The tip 4135 is a corner located at the tip end when each needle-like electrode portion 41 is viewed from the thickness direction. Since the tip portion 413 of each needle electrode portion 41 has a rounded shape, electric field concentration is alleviated to some extent. Therefore, large variations in the intensity of electric field concentration due to manufacturing variations in forming each needle-like electrode part 41 can be suppressed.

12A and 12B show a modification in which the end edge 4137 of the tip portion 413 of each needle-shaped electrode portion 41 is chamfered. The edge portion 4137 is an edge portion of a 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 electrode portion 41, electric field concentration is alleviated to some extent. Therefore, large variations in the intensity of electric field concentration due to manufacturing variations in forming each needle-like electrode part 41 can be suppressed.

FIG. 13 shows a main part of the mold device 9 that chamfers the end edge 4137 of each needle electrode part 41. The mold device 9 includes an upper mold 91 and a lower mold 92 for bending. The mold device 9 bends each needle electrode part 41 on a flat surface 93 provided on the side of the lower mold 92 when bending each needle electrode part 41 between the upper mold 91 and the lower mold 92. The edge portion 4137 of the portion 41 is crushed all at once and chamfered. According to this mold device 9, when bending each needle-shaped electrode portion 41, the end edge portion 4137 can be chamfered at the same time. In addition, when chamfering each needle electrode portion 41, the positions of the tip portions 413 of each needle electrode portion 41 (positions of edge portions 4137) are aligned, and as a result, the positions of the tip portions 413 of each needle electrode portion 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 electrode part 41 is relaxed, and variations in the strength of the electric field concentration are suppressed, but when the electric field concentration is relaxed, it becomes difficult to develop into a leader discharge. There are also trends. 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 parts 41, the progression to leader discharge is stably promoted.

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

(Ninth embodiment)
A discharge device according to the ninth embodiment will be described based on FIGS. 15A to 19. Note that detailed explanations 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 resistance element 601, a pair of lead wires 602 electrically and mechanically connected to the resistance element 601, and a terminal electrically and mechanically connected to the end 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 that can suppress bending. Since the lead wire 602 covered by the cover 605 maintains 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 fixing base 81 is integrally attached to a housing 80 that supports the discharge electrode 1 and the counter electrode 4.

A resistive element 601 and each terminal 603 are fixed to the fixed base 81 at respective predetermined positions. Thereby, each lead wire 602 is held at a predetermined position on the fixing base 81, and the risk of each lead wire 602 being repeatedly bent is suppressed. A peripheral wall 811 stands up from the peripheral edge of the fixed base 81. The peripheral wall 811 is located so as to surround at least the resistance element 601 and the pair of lead wires 602 of the resistor 60.

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

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

In the modification shown in FIG. 17, a resistor 60 is electrically and mechanically directly connected to the counter electrode 4, and furthermore, the resistor 60 is fixed to the outer surface of the casing 80. In this modification, a portion on the back side of the casing 80 (the side opposite to the side where the counter electrode 4 is located) also serves as the fixing base 81.

The modified examples shown in FIGS. 16 and 17 are examples in which the limiting resistor 6 is directly attached to the counter electrode 4. In other words, the length of the wiring between the counter electrode 4 and the limiting resistor 6 is set to 0 mm. It is. When the limiting resistor 6 is disposed in the first energizing path 51, the length of the wiring between the counter electrode 4 and the limiting resistor 6 is preferably set within the range of 0 to 30 mm. This is because when the instantaneous current flows through a dielectrically broken discharge path, the current resistance becomes very small, so if the length of the wiring between the counter electrode 4 and the limiting resistor 6 exceeds 30 mm, the stray capacitance of that wiring This is because the discharge becomes unstable due to the influence of

The measurement results shown in the graph of FIG. 18A also confirm 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 leader discharge decreases. be done. Although no numerical value is shown on the vertical axis of FIG. 18A, the upper limit of the amount of generated radicals is about 5 trillion/sec.

Further, when the limiting resistor 6 is disposed in the first energizing path 51, the length between the voltage application section 2 and the limiting resistor 6 in the first energizing path 51 may be set within a range of 0 to 200 mm. preferable. This is because when an instantaneous current flows, the current resistance becomes very small, so if the length of the wiring between the voltage application section 2 and the limiting resistor 6 exceeds 200 mm, the discharge will not be possible due to the influence of the stray capacitance of the wiring. 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 application electrode section 2 and the limiting resistor 6 exceeds 200 mm, the amount of active ingredients (radical amount) generated by 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 measured using the apparatus schematically shown in FIG. 19. In this device, a limiting resistor 6 is placed 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 between the electrode and a discharge electrode (not shown), and the amount of radicals generated by leader discharge was measured.

The above results are the results when the limiting resistor 6 is arranged in the first energizing path 51, but when the limiting resistor 6 is arranged in the second energizing path 52 that electrically connects the discharge electrode 1 and the voltage application section 2. A similar result can be obtained when (see FIG. 4B).

In other words, when the limiting resistor 6 is disposed in the second energizing path 52, setting the length between the discharge electrode 1 and the limiting resistor 6 in the second energizing path 52 to within 30 mm stabilizes the leader discharge. It is preferable to cause this to occur. In addition, it is preferable to set the length between the voltage application section 2 and the limiting resistor 6 in the second energizing path 52 to within 200 mm in order to stably generate the leader discharge.

(10th embodiment)
The discharge device of the tenth embodiment will be explained based on FIGS. 20 to 22. Note that detailed explanations of configurations similar to those described in the eighth embodiment will be omitted.

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

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 this embodiment, among the exposed portions (portions not buried in the housing 80) of each heat sink 302, corner portions are chamfered in the area around 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. The stage-shaped portion 3025 on which the Peltier element 301 is mounted is not chamfered.

The chamfering of each heat sink 302 is done when coating each heat sink 302 by dipping it in a coating agent such as a resin (for example, urethane-based ultraviolet curing resin). It is done to cover the This is because each heat dissipation plate 302 is manufactured by die-cutting a sheet metal, so after die-cutting, a corner portion that is substantially perpendicular to the edge thereof is formed. If each heat sink 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 heat sink 302 is likely to be exposed.

In the discharge device of this embodiment, a leader discharge with higher energy than corona discharge is generated, so that the acidity of the liquid 35 (condensed water) supplied to the discharge electrode 1 tends to be further strengthened. Therefore, if a portion of each heat sink 302 is exposed from the coating, that portion will oxidize (corrode) and its durability will decrease.

Another possible countermeasure to this problem is to increase the overall thickness of the coating to suppress exposure. However, since the coating is applied to cover each heat dissipation plate 302 and the entire Peltier element 301 mounted thereon from the cooling side to the heat dissipation side, if the overall thickness of the coating increases, the Peltier element 301 Cooling performance will deteriorate. According to the discharge device of this embodiment, it is possible to suppress deterioration of each heat sink 302 and solder while suppressing the thickness of the coating.

(Eleventh embodiment)
A discharge device according to an eleventh embodiment will be described based on FIGS. 23 and 24. Note that detailed explanations of configurations similar to those described in the eighth embodiment will be omitted.

In the discharge device of this embodiment, in order to adjust the discharge frequency (frequency of instantaneous current) in leader discharge, instead of placing a capacitor on the high voltage side as in the discharge device of the fourth embodiment, the capacitor is returned to the low voltage side. A time control section 85 is arranged.

FIG. 23 is a block diagram showing the main parts of the discharge device of this embodiment. As shown in FIG. 23, the discharge device of this embodiment includes, in addition to the high voltage generation circuit 20 constituting 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. and an input section 87.

When power is supplied to the input section 87, the high voltage drive circuit 86 operates and a high voltage is output from the high voltage generation circuit 20. When the control signal regarding 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. Generates a control signal to Based on this control signal, the high voltage drive circuit 86 increases the output voltage until it reaches a predetermined discharge voltage, and when a discharge accompanied by dielectric breakdown occurs and the output voltage decreases, the output voltage is increased again to the predetermined discharge voltage. Repeat the task of This causes leader discharge.

In the discharge device of this embodiment, the feedback time control section 85 can control the feedback time from when the output voltage decreases until it returns to a predetermined discharge voltage. By controlling the feedback time, the discharge frequency of the leader discharge can be 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 a feedback time control section 85. Furthermore, it is also possible to configure the microcomputer 861 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, so there is an advantage that the discharge characteristics can be adjusted over a wide range, and the number of components on the high voltage side is increased. This has the advantage of reducing costs, and as a result, reducing costs.

As described above, the discharge device according to the present invention generates active ingredients through leader discharge and can suppress the increase in ozone. It can be applied to a variety of uses such as utensils, facial beauty devices, and automobiles.

1 Discharge electrode 13 Tip part 15 Base end part 2 Voltage application part 3 Liquid supply part 35 Liquid 4 Opposed electrode 41 Needle electrode part 410 Convex surface 413 Tip part 415 Base end part 417 Groove part 42 Support electrode part 420 Opposing surface 43 Opening part 45 Stepped portion 5 Current conducting path 51 First current conducting path 52 Second current conducting path 6 Limiting resistor 7 Capacitor 9 Mold device 91 Upper mold 92 Lower mold 9 Mold device 93 One side T1 Thickness direction D1 Tip portion of needle-like electrode portion and discharge electrode D2 Distance between the proximal end of the needle electrode part and the discharge electrode D3 Distance between the supporting electrode part and the discharge electrode

Claims (5)

a discharge electrode;
a voltage application unit that applies a voltage to the discharge electrode to cause discharge to occur in the discharge electrode;
a voltage control section and a current control section that receive the output of the voltage application section and generate control signals for controlling the voltage and current to predetermined values;
High-voltage drive that increases the output voltage until it reaches a predetermined discharge voltage based on the control signal, and when a discharge accompanied by dielectric breakdown occurs and the output voltage decreases, the output voltage is increased again to the predetermined discharge voltage. circuit and
A discharge device comprising: a feedback time control section that controls a feedback time from when the output voltage decreases until it returns to a predetermined discharge voltage again. The discharge device according to claim 1, wherein the discharge is a discharge that has further developed from a corona discharge, and is a discharge that intermittently generates a dielectrically broken discharge path extending from the discharge electrode to the surrounding area. further comprising a liquid supply unit that supplies liquid to the discharge electrode,
The discharge device according to claim 1 or 2, wherein the liquid supplied to the discharge electrode is electrostatically atomized by the discharge. further comprising a counter electrode located opposite to the discharge electrode,
The discharge is
4. The discharge is a discharge that intermittently generates a dielectrically broken discharge path between the discharge electrode and the counter electrode so as to connect the two. Discharge device. The discharge device according to claim 4, wherein the counter electrode includes a needle-like electrode portion facing the discharge electrode.

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