Patent Description:
In a closed space, such as houses, rooms, shopping malls, factories, and offices, high concentration aerosols may have a negative effect on the health of people. The aerosol may be generated by smoking, cooking, cleaning, welding, grinding, etc. in a closed space.

An electrostatic dust collecting apparatus is an apparatus for removing such aerosols and may be used for an air cleaner or an air conditioner having an air cleaning function.

The electrostatic dust collecting apparatus may include a dust collecting unit having a high voltage electrode and a low voltage electrode, and require a spacer to separate the high voltage electrode from the low voltage electrode. The spacer allows the high-voltage electrode and the low-voltage electrode to be spaced at a uniform distance, so that the electrostatic dust collecting apparatus may stably implement the performance.

For instance, <CIT> relates to a collector cell for an electrostatic precipitator for removing small dust particles from gas or air, said collector cell being according to the preamble of the independent claim <NUM>.

It is an object of the disclosure to provide an electrostatic dust collecting apparatus in which a sufficient distance between a high voltage electrode and a low voltage electrode is secured.

It is another object of the disclosure to provide an electrostatic dust collecting apparatus including a support member having a simple shape.

It is another object of the disclosure to provide an electrostatic dust collecting apparatus capable of reducing leakage of current, so that the output of a power supply device may be reduced.

It is another object of the disclosure to provide a method of manufacturing an electrostatic dust collecting apparatus that may simplify the manufacturing process and reducing the manufacturing cost.

According to an aspect of the disclosure, there is provided an electrostatic dust collecting apparatus including: a plurality of first electrodes and a plurality of second electrodes that are alternately stacked along a first direction; a plurality of support members configured to maintain an interval between a first electrode and a second electrode spaced apart from each other; and a support bar formed to extend along the first direction, wherein the at least one support member each includes at least one electrode insertion groove formed to allow at least one of the first electrode or the second electrode to be inserted thereinto and a coupling hole extending along the first direction and formed to allow the support bar to be coupled thereto. Each support member is formed of insulating material and the support members are stacked on each other in the first direction while being in contact with each other.

The support members may each include a body formed with the coupling hole and an electrode insertion portion formed with the at least one electrode insertion groove.

The support members may include a first support member into which the first electrode is inserted and a second support member into which the second electrode is inserted, and the first support member and the second support may be supported while in contact with each other along the first direction such that the first electrode and the second electrode are stacked along the first direction.

The support members may be provided to surround opposite end portions of at least one of the first electrode or the second electrode along a short side of the at least one of the first electrode or the second electrode.

The support members may each include a guide protrusion protruding from the electrode insertion portion along the first direction and a guide groove formed to correspond to the guide protrusion.

The guide protrusion may protrude from an upper portion of the electrode insertion portion, and the guide groove may be recessed from a lower portion of the electrode insertion portion.

The support members may further include a first support member into which the first electrode is inserted and a second support member into which the second electrode is inserted, wherein the guide groove of the first support member and the guide protrusion of the second support member may be coupled to each other.

The at least one electrode insertion groove may include a first electrode insertion groove into which the first electrode is inserted and a second electrode insertion groove spaced apart from the first electrode insertion groove along the first direction and into which the second electrode is inserted.

The support members may each include a fixing device configured to fix at least one of the first electrode or the second electrode.

The fixing device may include at least one of a hook protruding from the electrode insertion groove toward the at least one electrode insertion groove or an adhesive member.

The hook may protrude from an upper portion of the electrode insertion portion.

The first electrode may be a high voltage electrode, and the second electrode is a low voltage electrode.

A support member having a simple shape can sufficiently secure an interval between a high voltage electrode and a low voltage electrode, and reduce leakage of current between the electrodes.

Use of the support member having a simple shape reduces the output of a power supply device, so that the operating cost of the electrostatic dust collecting apparatus can be reduced.

The electrostatic dust collecting apparatus can be manufactured in a simplified manufacturing process and at reduced manufacturing cost.

The embodiments set forth herein and illustrated in the configuration of the disclosure are only the most preferred embodiments and are not representative of the full disclosure, so it should be understood that they may be replaced with various equivalents and modifications, provided that said equivalents and modifications fall within the scope of the appended claims.

The terms including ordinal numbers like "first" and "second" may be used to explain various components, but the components are not limited by the terms. The terms are only for the purpose of distinguishing a component from another. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the disclosure. Descriptions shall be understood as to include any and all combinations of one or more of the associated listed items when the items are described by using the conjunctive term "~ and/or ~," or the like.

The terms "front", "rear", "upper", "lower", "top", and "bottom" as herein used are defined with respect to the drawings, but the terms may not restrict the shape and position of the respective components.

<FIG> is a schematic diagram illustrating an electrostatic dust collecting apparatus according to an embodiment of the disclosure. <FIG> is a view illustrating the electrostatic dust collecting apparatus according to an embodiment of the disclosure. <FIG> is an exploded view illustrating the electrostatic dust collecting apparatus shown in <FIG>.

Referring to <FIG>, an electrostatic dust collecting apparatus <NUM> may include a charging unit <NUM> and a dust collecting unit <NUM> installed downstream of the charging unit <NUM>.

The electrostatic dust collecting apparatus <NUM> is provided to, through a blower fan (not shown) provided upstream or downstream of the electrostatic dust collecting apparatus <NUM>, cause air introduced into the charging unit <NUM> along a direction F shown in <FIG> to pass through the collecting unit <NUM> and then flow to the outside again.

The charging unit <NUM> includes a discharge electrode <NUM> and a counter electrode <NUM> disposed between the discharge electrodes <NUM>. The discharge electrode <NUM> is formed as a wire electrode installed between a pair of the counter electrodes <NUM>, in general, as a tungsten wire.

In <FIG>, for the sake of convenience of description, the discharge electrode <NUM> is illustrated as being disposed between a pair of the counter electrodes <NUM>, but the charging unit may include a plurality of discharge electrodes and a plurality of counter electrodes alternately disposed between the plurality of discharge electrodes.

When a voltage is applied to the discharge electrode <NUM> (e.g., a voltage of <NUM> kV to <NUM> kV), the discharge electrode <NUM> and the counter electrode has corona discharge, which allows contaminants in the air to be charged with positive polarity (+) or negative polarity (-). For the sake of convenience of description, the following description will be made on an example that contaminants in the air passing through the charging unit <NUM> are charged with a positive polarity.

The dust collecting unit <NUM> has a structure in which a plurality of positive electrodes <NUM> in a plate shape and a plurality of negative electrodes <NUM> in a plate shape are stacked at regular intervals. For example, the positive electrode <NUM> and the negative electrode <NUM> may be formed by printing carbon ink on a surface of a laminated film or may be formed as a metal plate, such as an aluminum plate.

Accordingly, when a constant voltage is applied between the positive electrode <NUM> and the negative electrode <NUM> of the dust collecting unit <NUM>, an electric field is formed between the positive electrode <NUM> and the negative electrode <NUM>. Here, the positive electrode and the negative electrode are determined based on the potential difference between the two electrodes by referring a high-level electrode as a positive electrode and a low level electrode as a negative electrode. The positive electrode <NUM> may form a first electrode <NUM>. The negative electrode <NUM> may form a second electrode <NUM>.

Contaminants that are positively charged by passing through the charging unit <NUM> may be attached to the negative electrode <NUM> of the dust collecting unit <NUM> while passing through the dust collecting unit <NUM> disposed downstream of the charging unit <NUM>. With such a configuration, contaminants in the air may be removed. Accordingly, the air passing through the dust collecting unit <NUM> may be discharged from the electrostatic dust collecting apparatus <NUM> in a clean state with pollutants removed therefrom.

The dust collecting unit <NUM> may include a dust collection sheet <NUM> and first and second covers <NUM> and <NUM> covering the dust collection sheet <NUM>.

The first and second covers <NUM> and <NUM> may be provided in a frame shape surrounding the outer periphery of the dust collecting sheet <NUM>, and have openings <NUM> and <NUM> at an inner side thereof so that air passing through the charging unit <NUM> passes through the dust collecting sheet <NUM>.

A power connection member (not shown) connected to the dust collecting sheet <NUM> and applying power to the dust collecting sheet <NUM> may be disposed on the first and second covers <NUM> and <NUM>.

The dust collecting sheet <NUM> includes a plurality of electrodes stacked one on top of each other.

<FIG> is a diagram illustrating first and second electrodes of the electrostatic dust collecting apparatus shown in <FIG>. <FIG> is a view showing a cross-section of the electrostatic dust collecting apparatus shown in <FIG> when viewed in the X direction. <FIG> is a view showing a cross-section of the electrostatic dust collecting apparatus shown in <FIG> when viewed in the Y direction.

Referring to <FIG>, the first electrode <NUM> may be disposed on the upper side, and the second electrode <NUM> may be disposed on the lower side. A support member <NUM> may be disposed between the first electrode <NUM> and the second electrode <NUM>. The support member <NUM> may be disposed to maintain an interval between the first electrode <NUM> and the second electrode <NUM>.

The support member <NUM> may be provided in at least one unit thereof. The support member <NUM> may be provided to surround each of opposite end portions of the first electrode <NUM> and the second electrode <NUM> along the short side of the first electrode <NUM> and the second electrode <NUM>. That is, the support member <NUM> may be disposed to surround opposite end portions of the first electrode <NUM> and the second electrode <NUM> along the Y direction. Therefore, the electrodes <NUM> and <NUM> and the support member <NUM> are not easily separated from each other and may be firmly coupled to each other.

The at least one support member <NUM> may be disposed to be spaced apart from each other.

The support member <NUM> is formed of an insulating material. As such, since the interval between the first electrode <NUM> and the second electrode <NUM> is secured by the insulating material, insulation breakdown may be prevented.

The support member <NUM> may include a first support member <NUM> and a second support member <NUM>. The first support member <NUM> may be formed to allow the first electrode <NUM> to be inserted thereinto. The second support member <NUM> may be formed to allow the second electrode <NUM> to be inserted thereinto.

Each of the first support member <NUM> and the second support member <NUM> may be provided in plural.

The plurality of first support members <NUM> may be disposed to be spaced apart from each other in the X direction. That is, the plurality of first support members <NUM> may be coupled to the first electrodes <NUM> while being spaced apart from each other along the X direction. The plurality of second support members <NUM> are also disposed to be spaced apart from each other along the X direction, and may be coupled to the second electrodes <NUM>.

The first support member <NUM> and the second support member <NUM> may be supported by and come in contact with each other such that the first electrode <NUM> and the second electrode <NUM> are stacked one on top of each other along the Z direction. That is, the lower surface of the first support member <NUM> and the upper surface of the second support member <NUM> may come in contact with each other, and the lower surface of the second support member <NUM> and the upper surface of another first support member <NUM> among the plurality of first support members <NUM> may come in contact with each other.

Air for removing aerosol may pass through a region between the first electrode <NUM> and the second electrode <NUM> along the Y direction.

<FIG> is a view illustrating a support member of the electrostatic dust collecting apparatus shown in <FIG>. <FIG> is a view illustrating a support member of an electrostatic dust collecting apparatus according to another embodiment of the disclosure. <FIG> is a view showing a support member of an electric precipitator according to still another embodiment of the disclosure. <FIG> is a view showing a support member of an electric precipitator according to still another embodiment of the disclosure;.

Referring to <FIG>, the support member may include a body <NUM> and an electrode insertion portion <NUM>.

The body <NUM> may include a coupling hole 301a formed to be coupled to a support rod <NUM>. The coupling hole 301a may pass through the body <NUM> along the Z direction. Therefore, the support rod <NUM>, which will be described below, may be coupled to the coupling hole 301a of the at least one support member <NUM> to thereby connect the support rod <NUM> to the first electrode <NUM> and the second electrode <NUM>. The coupling hole 301a is illustrated in a cylindrical shape, but is not limited thereto, and may be formed corresponding to the shape of the support rod <NUM>. Therefore, the coupling hole 301a may include other various shapes than a cylindrical shape as long as it can be coupled to the support rod <NUM>.

Referring to <FIG>, the body <NUM> may further include a fitting hole 301b connecting to the coupling hole 301a. The fitting hole 301b may be formed to allow the support rod <NUM> to be coupled to the coupling hole 301a therethrough. That is, the support rod <NUM> may be fitted into the fitting hole 301b.

Due to the coupling hole and the support rod, the at least one support member and the electrodes may be stably stacked, and the process may be simplified so that the manufacturing cost may be reduced.

The electrode insertion portion <NUM> may include an upper portion 302a, a lower portion 302b, and an electrode insertion groove <NUM>.

The upper portion 302a and the lower portion 302b may formed to protrude from the body <NUM> along the Y direction. The electrode insertion groove <NUM> may be provided between the upper portion 302a and the lower portion 302b. The electrode insertion groove <NUM> may be formed to allow the first electrode <NUM> or the second electrode <NUM> to be insertedly fitted thereto. In the drawing, the electrode insertion groove <NUM> is illustrated in a quadrangular shape, but is not limited thereto and may be formed to correspond to the shape of the end portion of the electrode. Thus, the electrode insertion groove <NUM> may also include a rounded shape. In addition, the position of the electrode insertion groove <NUM> is illustrated in the middle between the upper portion 302a and the lower portion 302b, but is not limited thereto, and the electrode insertion groove <NUM> may be formed at a side adjacent to the upper portion 302a or the lower portion 302b.

Each of the support members <NUM> may further include a fixing device <NUM> for fixing the electrode inserted thereinto. The fixing device <NUM> may further include an adhesive member 306a and a hook 306b. Due to the fixing device <NUM>, the coupling between the electrode and the support member <NUM> may be prevented from being easily release.

The adhesive member 306a may be formed on a surface adjacent to the electrode insertion groove <NUM> in the electrode insertion portion <NUM>. The adhesive member 306a may be formed in a shape corresponding to the electrode insertion groove <NUM>. That is, the adhesive member 306a may be disposed at a portion of the electrode insertion portion <NUM> that comes in contact with the electrode.

The hook 306b may protrude in a direction toward the electrode insertion groove <NUM> from the upper portion 302a or the lower portion 302b of the electrode insertion portion <NUM>. In the drawing, the hook 306b is illustrated as protruding from the upper portion 302a along the Z direction, but is not limited thereto and may protrude from the lower portion 302b along the Z direction. When the hook 306b is formed on the support member <NUM>, the first electrode <NUM> and the second electrode <NUM> may be formed with a groove in a shape corresponding to the hook 306b. The shape of the hook 306b is not limited to that shown in the drawing, and may include various shapes.

<FIG> is a view showing a support member of an electric precipitator according to still another embodiment of the disclosure. <FIG> is a view showing a support member of an electric precipitator according to still another embodiment of the disclosure. <FIG> is a view showing a cross section of the electrostatic dust collecting apparatus shown in <FIG>, when viewed in the X direction. <FIG> is a view showing a cross section of the electrostatic dust collecting apparatus shown in <FIG>, when viewed in the Y direction.

Referring to <FIG> and <FIG>, the electrode insertion groove <NUM> may be formed in at least one unit thereof. That is, the at least one electrode insertion groove <NUM> may include a first electrode insertion groove 303a and a second electrode insertion groove 303b. The first electrode insertion groove 303a and the second electrode insertion groove 303b may each be coupled to the first electrode <NUM> or the second electrode <NUM>. For example, the first electrode <NUM> may be inserted into the first electrode insertion groove 303a, and the second electrode <NUM> may be inserted into the second electrode insertion groove 303b. Conversely, the first electrode <NUM> may be inserted into the second electrode insertion groove 303b, and the second electrode <NUM> may be inserted into the first electrode insertion groove 303a. Since both the first electrode and the second electrode may be inserted into one support member, the number of the support members may be reduced, and management of the support members may be facilitated.

An intermediate portion 302c may be formed between the first electrode insertion groove 303a and the second electrode insertion groove 303b.

Each of the support members <NUM> may further include a guide protrusion <NUM> and a guide groove <NUM>. The guide protrusion <NUM> and the guide groove <NUM> may extend along the Z direction from the electrode insertion portion <NUM>. The guide protrusion <NUM> may be formed to protrude from the upper portion 302a, and the guide groove <NUM> may be formed to be recessed from the lower portion 302b. However, the disclosure is not limited thereto, and the guide protrusion <NUM> may protrude from the lower portion 302b, and the guide groove <NUM> may be recessed from the upper portion 302a.

The guide protrusion <NUM> and the guide groove <NUM> may be formed to correspond to each other. The guide protrusion <NUM> and the guide groove <NUM> are illustrated in a cylindrical shape, but are not limited thereto, and may include various shapes as long as they allow the support members <NUM> to be coupled to each other.

When the support members <NUM> are coupled to each other while in contact with each other due to the guide protrusion <NUM> and the guide groove <NUM>, the support members may be stably coupled to each other and prevented from being separated from each other.

<FIG> is a view showing a cross section of an electrostatic dust collecting apparatus according to still another embodiment of the disclosure, when viewed in the X direction. <FIG> is a view showing a cross section of the electrostatic dust collecting apparatus shown in <FIG>, when viewed in the Y direction.

Referring to <FIG>, the support member <NUM> may be coupled to the first electrode <NUM> and the second electrode <NUM> may be disposed between the support members <NUM>. That is, the support member <NUM> may not be coupled to the second electrode <NUM>. However, alternatively, the second electrode <NUM> may be coupled to the support member, and the first electrode <NUM> may be disposed between the support members <NUM>.

According to the above-described embodiment, the spacing between electrodes may be maintained with a small number of support members <NUM>, so that the material cost may be reduced.

<FIG> is a diagram showing a method of manufacturing an electrostatic dust collecting apparatus according to an embodiment of the disclosure. <FIG> is an enlarged view of portion A shown in <FIG>.

Referring to <FIG>, the dust collecting unit may be formed by installing the support rod <NUM> on the dust collecting case <NUM> and then alternately stacking the first electrodes <NUM> and the second electrodes <NUM> one on top of another. In this case, the support members are coupled to the first electrode <NUM> and the second electrode <NUM>, and the support rod <NUM> may be coupled to the support members <NUM> through the coupling holes 301a.

<FIG> is a diagram showing a method of manufacturing an electrostatic dust collecting apparatus according to another embodiment of the disclosure. <FIG> is an enlarged view of portion B shown in <FIG>.

Referring to <FIG>, the dust collecting unit may be formed by inserting the support rod <NUM> into the support members <NUM> that are stacked as the first electrode <NUM> and the second electrode <NUM> are alternately on the dust collection case <NUM>.

<FIG> is a view showing an electrostatic dust collecting apparatus according to still another embodiment, which is not part of the disclosure. <FIG> is a view showing a method of manufacturing an electrostatic dust collecting apparatus according to still another embodiment, which is not part of the disclosure. <FIG> is a view showing a method of manufacturing an electrostatic dust collecting apparatus according to still another embodiment, which is not part of the disclosure.

Referring to <FIG>, and <FIG>, the first electrode <NUM> and the second electrode <NUM> may have at least one support member <NUM> disposed therebetween. The support members <NUM> may be disposed to be spaced apart from each other.

The support member <NUM> may be formed of a heat-melting adhesive, such as hot melt. While the first electrode <NUM> and the second electrode <NUM> is proceeding along a direction P through a transfer roller <NUM>, the hot melt may be applied in a predetermined width and height through a nozzle <NUM>.

Subsequently, the applied hot melt is dried, and the dried support member <NUM> may be cut. That is, referring to <FIG>, the first electrode <NUM> and the second electrode <NUM> are continually formed on one electrode fabric, and after the support members <NUM> are dried, are separately cut into the first electrode <NUM> and the first electrode <NUM>. Alternatively, referring to <FIG>, the electrodes may be supplied in the form of the first electrode <NUM> and the second electrode <NUM> cut as separate electrodes and the support members <NUM> may be applied on the first electrode <NUM> and the second electrode <NUM> and cut. The transfer roller <NUM> may adjust the thickness of the support member <NUM> by adjusting the transfer speed of the first electrode <NUM> and the second electrode <NUM> according to the rotation speed. That is, when the transfer speed is high, the thickness of the support member <NUM> becomes thinner, and when the transfer speed is low, the thickness of the support member <NUM> becomes thicker.

Electrodes obtained through the above process may be stacked one on top of another and formed as shown in <FIG>. The application method is not limited to a spray method by the nozzle <NUM> and may be implemented in various ways, such as application through a roller (not shown).

<FIG> is a view showing a method of manufacturing an electrostatic dust collecting apparatus according to still another embodiment, which is not part of the disclosure. <FIG> is a cross-sectional view illustrating a stacking method of the electrostatic dust collecting apparatus shown in <FIG>, when viewed in the X direction. <FIG> is a cross-sectional view illustrating a stacking method of the electrostatic dust collecting apparatus shown in <FIG>, when viewed in the Y direction.

Referring to <FIG>, the first electrode <NUM> and the second electrode <NUM> are arranged along the Y direction, and a support member <NUM> may be disposed between the first electrode <NUM> and the second electrode <NUM>. The support member <NUM> may include a bending portion <NUM> and a connecting portion <NUM>.

The connecting portion <NUM> may be provided to connect the bending portions <NUM> provided on opposite sides of the connecting portion <NUM>.

The support member <NUM> may be formed of a flexible material to be bent. Each of the first electrode <NUM> and the second electrode <NUM> may be attached to the support member <NUM>. That is, the first electrode <NUM> and the second electrode <NUM> may be disposed on the connecting portions <NUM> and stacked along the Z direction. Accordingly, the first electrode <NUM> and the second electrode <NUM> may be disposed opposite to each other while being spaced apart from each other, and a space for passing air may be provided therebetween. The support member <NUM> may be attached to surround opposite end portions of each of the first electrode <NUM> and the second electrode <NUM> along the short side of the first electrode <NUM> and the second electrode <NUM>.

In order to directly couple the support member <NUM> to the electrode, an adhesive member may be attached between the first electrode <NUM> and the support member <NUM> and between the second electrode <NUM> and the support member <NUM>. That is, an adhesive member may be attached between the connecting portion <NUM> and at least one of the first electrode <NUM> or the second electrode <NUM>.

The bending portion <NUM> may be provided in plural. The plurality of bending portion <NUM> are provided to be spaced apart from each other and may be connected to each other through the connecting portion <NUM>.

Both the first electrode <NUM> and the second electrode <NUM> may be attached to the support member <NUM> that extends. Therefore, a separate process of cutting the support member <NUM> is not required, so that the manufacturing cost may be reduced.

<FIG> is a cross-sectional view illustrating a stacking method of an electrostatic dust collecting apparatus according to another embodiment, which is not part of the disclosure, when viewed in the X direction. <FIG> is a cross-sectional view illustrating a stacking method of the electrostatic dust collecting apparatus shown in <FIG>, when viewed in the Y direction.

Referring to <FIG> and <FIG>, a plurality of support members <NUM> may be provided. The support member <NUM> may include a first support member <NUM> and a second support member <NUM>. The first support member <NUM> may include a bending portion <NUM> and a connecting portion <NUM>, and the second support member <NUM> may also include a bending portion <NUM> and a connecting portion <NUM>.

The support members <NUM> may be attached to opposite end portions of each of the first electrode <NUM> and the second electrode <NUM> along the short side of the first electrode <NUM> and the second electrode <NUM>. The support members <NUM> may be attached to surround the opposite end portions. The connecting portions <NUM>, <NUM> are attached to the first electrode <NUM> and the second electrode <NUM>, and allow the bending portion <NUM>, <NUM> to be connected to the electrodes. The bending portion <NUM>, <NUM> and the connecting portion <NUM>, <NUM> may allow the first electrode <NUM> and the second electrode <NUM> to face each other while maintaining an interval between the first electrode <NUM> and the second electrode <NUM>.

The first support member <NUM> and the second support member <NUM> may be disposed to be spaced apart from each other. At opposite end portions along the short side of the electrode, the first support member <NUM> may be attached to one end portion of the first electrode <NUM>, and the second support member <NUM> may be attached to one end portion of the second electrode <NUM>. Accordingly, the first support member <NUM> may be formed to surround the first electrode <NUM>, and the second support member <NUM> may be formed to surround the second electrode <NUM>.

The first support member <NUM> and the second support member <NUM> may allow the first electrode <NUM> and the second electrode <NUM> to face each other while maintaining an interval between the first electrode <NUM> and the second electrode <NUM>.

Claim 1:
An electrostatic dust collecting apparatus (<NUM>) comprising:
a plurality of first electrodes (<NUM>) and
a plurality of second electrodes (<NUM>) that are alternately stacked along a direction (Z);
a plurality of support members (<NUM>) configured to space apart the first electrodes (<NUM>) and the second electrodes (<NUM>) from each other; and
a support bar (<NUM>) formed to extend along the direction (Z),
wherein each of the plurality of support members (<NUM>) includes at least one electrode insertion groove (<NUM>) formed to allow at least one of a first electrode (<NUM>) or a second electrode (<NUM>) to be inserted and a coupling hole (301a) formed along the direction (Z), wherein the support bar (<NUM>) is inserted in the coupling holes (301a) of the plurality of support members (<NUM>),
characterized in that
each of the plurality of support members (<NUM>) is formed of an insulating material; and
the support members (<NUM>) are stacked in the direction (Z) while being in contact with each other.