Patent Description:
There have been conventionally known discharge units which discharge between a discharge electrode and a counter electrode. A discharge unit is mounted on such a device as an air conditioner, an air cleaner, or the like (e.g. Patent Literature <NUM>). In the discharge unit recited in paragraphs <NUM> and <NUM> and <FIG> of Patent Literature <NUM>, a discharge electrode is fixed to an electrode fixing plate of a sheet metal member, and the sheet metal member is fixed to a counter electrode by using a fixing insulator. Specifically, the sheet metal member and the fixing insulator configure an integral supporting member, and this supporting member supports the discharge electrode and the counter electrode.

When such a device as an air conditioner, an air cleaner, or the like is operated to use a discharge unit, conductive contaminants such as tobacco stains included in room air, ammonium nitrate generated by discharging, and the like adhere to a supporting member. In a structure where a discharge electrode and a counter electrode are supported by an integral supporting member, when more contaminants adhere to the supporting member, insulating properties between the discharge electrode and the counter electrode might be deteriorated. Then, when further more contaminants are adhered to cause the discharge electrode to connect to the counter electrode, the discharge electrode and the counter electrode conduct with each other to prevent discharging.

<CIT> discloses an induction electrode having a needle-like discharge electrode, a plate-like portion in which a through hole into which a tip portion of the discharge electrode is inserted, and a leg portion protruding from the plate-like portion. An ion generating element which supports an electrode and the leg portion and includes a supporting substrate on which the tip portion and the plate portion are both disposed on one side of the supporting substrate. A supporting position of the leg portion, a longitudinal direction thereof intersects a juxtaposition direction of the support position of the discharge electrode and the support position of the leg portion, and a slit penetrating the support substrate is formed.

<CIT> discloses an ion generating element for generating positive ions and negative ions by corona discharge, comprising: an induction electrode and a discharge electrode for generating a corona discharge between the induction electrode and the discharge electrode, A first needle electrode that generates positive ions by causing corona discharge with an induction electrode, and a second needle-like electrode that generates negative ions by causing corona discharge between the induction electrode and the first needle- And an electrode formed between the first needle electrode and the second needle electrode, the wall being made of an insulator.

<CIT> discloses an active species emission unit which comprises a case unit having either a cylindrical or box shape, further comprising an aperture unit on one end thereof. A discharge electrode, a leading end whereof is inserted via the aperture unit into the case unit, and a semiconductor electric unit which is positioned vertically facing the discharge electrode in the vicinity of the leading end thereof. A power source connection unit which serves as a ground potential is positioned on the exterior periphery of the semiconductor electric unit. Voltage is applied from a power source unit to the power source connection unit and the discharge electrode and an active species emitted by a corona discharge.

<CIT> discloses a discharge electrode which is made of a metal material, and includes a plate-like electrode support plate and a plurality of discharge sections arranged along, and supported at, a side edge portion of the electrode support plate so as to be opposed to a counter electrode.

An object of the present invention is to suppress deterioration of insulating properties between a discharge electrode and a counter electrode in a discharge unit provided with an insulation member having a surface continuous from the discharge electrode to the counter electrode.

The present invention provides a discharge unit according to claim <NUM>.

In the following, description will be made of a discharge unit according to an embodiment of the present invention with reference to the drawings. As shown in <FIG>, a discharge unit <NUM> according to the present embodiment can be mounted in, for example, an air conditioning device <NUM>. The air conditioning device <NUM> shown in <FIG> adjusts temperature of air in a room space S.

As shown in <FIG>, the air conditioning device <NUM> is disposed on a back face of a ceiling C. The air conditioning device <NUM> includes an oblong box-shaped air-conditioning casing <NUM>. An inside air duct <NUM> is connected to one side surface of the air-conditioning casing <NUM> in a longitudinal direction. An air supply duct <NUM> is connected to the other side surface of the air-conditioning casing <NUM> in the longitudinal direction. Inside the air-conditioning casing <NUM>, an air passage 11a is formed. The inside air duct <NUM> has an inflow end communicating with the room space S and an outflow end communicating with the air passage 11a. The air supply duct <NUM> has an inflow end communicating with the air passage 11a and an outflow end communicating with the room space S.

In the air passage 11a, a prefilter <NUM>, the discharge unit <NUM>, a catalyst filter <NUM>, a heat exchanger <NUM>, and a fan <NUM> are arranged sequentially from an upstream side of an air flow (inside air duct <NUM> side) to a downstream side (air supply duct <NUM> side). The prefilter <NUM> collects relatively large dusts in air. The discharge unit <NUM> generates activated species along with discharging, and the activated species decompose harmful substances and odorous substances in the air.

The catalyst filter <NUM> is formed, for example, by a honeycomb-structure base material which supports a catalyst on a surface thereof. As the catalyst, manganese-based catalysts, precious metal-based catalysts, or the like are used. The catalyst filter <NUM> further activates the activated species generated by discharging to promote decomposition of harmful substances and odorous substances in the air. In the catalyst filter <NUM>, an absorbent (e.g., activated carbon) is supported which absorbs harmful substances and odorous substances in the air.

The heat exchanger <NUM> heats and cools air flowing through the air passage 11a. Specifically, the heat exchanger <NUM> is connected to a refrigerant circuit (not shown). In the refrigerant circuit, a charged refrigerant is circulated to have a refrigeration cycle. The heat exchanger <NUM> functions as an evaporator which cools air by a low-pressure refrigerant flowing inside thereof. Additionally, the heat exchanger <NUM> functions as a condenser which heats air by a high-pressure refrigerant flowing inside thereof. The fan <NUM> carries air in the air passage 11a.

The discharge unit <NUM> is configured to have a streamer discharge system. Specifically, the discharge unit <NUM> generates low-temperature plasma by streamer discharging, which is followed by generation of highly reactive activated species (high-speed electron, ion, radical, ozone, and the like) in the air. As shown in <FIG>, <FIG>, and <FIG>, the discharge unit <NUM> includes a casing <NUM>, a voltage supply unit <NUM> housed in the casing <NUM>, and a discharging processing unit <NUM> housed in the casing <NUM>.

As shown in <FIG> and <FIG>, the casing <NUM> is formed in a generally rectangular solid form with an oblong box-shape. The casing <NUM> is formed of an insulative resin material. The casing <NUM> is configured with a lower case portion <NUM>, and an upper case portion <NUM> attached to the top portion of the lower case portion <NUM>. Inside the casing <NUM>, a partition portion <NUM> is provided at a middle part of the casing <NUM> in a longitudinal direction (right-left direction) thereof. The partition portion <NUM> partitions an inner part of the casing <NUM> into two, right and left spaces. Of these spaces, the right space forms a housing chamber <NUM> and the left space forms a processing chamber <NUM> (ventilation passage).

The partition portion <NUM> is configured with an upper partition wall 23a and a lower partition wall <NUM>. The upper partition wall 23a is integrally formed inside the upper case portion <NUM>. The lower partition wall <NUM> is formed integrally with an insulation member <NUM>, which will be detailed later. In the partition portion <NUM>, the upper partition wall 23a and the lower partition wall <NUM> are arranged vertically adjacent to each other such that a lower face of the upper partition wall 23a and an upper face of the lower partition wall <NUM> are in contact with each other.

As shown in <FIG>, in a front face of the casing <NUM>, a first vent <NUM> (inflow port) is formed. The first vent <NUM> is arranged in a part closer to the left side of the casing <NUM> so as to communicate with the processing chamber <NUM>. Air flown into the first vent <NUM> flows to the inside of the processing chamber <NUM>.

As shown in <FIG>, in a rear face of the casing <NUM>, a second vent <NUM> (outflow port) is formed. The second vent <NUM> is arranged in a part closer to the left side of the casing <NUM> so as to communicate with the processing chamber <NUM>. The air inside the processing chamber <NUM> flows out of the casing <NUM>.

As shown in <FIG> and <FIG>, a slide cover <NUM> is provided at a right end in the middle of the upper case portion <NUM> in a front-rear direction. The slide cover <NUM> is formed to be detachable from a main body of the casing <NUM>. When the slide cover <NUM> is removed, a connector <NUM> of the voltage supply unit <NUM> (see <FIG>) is exposed to the outside of the casing <NUM>.

As shown in <FIG>, the voltage supply unit <NUM> is arranged in the housing chamber <NUM>. The voltage supply unit <NUM> is configured to supply a power supply voltage supplied from an external power supply to the discharging processing unit <NUM>. The voltage supply unit <NUM> includes a substrate <NUM>, the connector <NUM>, a power supply transformer <NUM>, and an earth terminal portion <NUM>. The substrate <NUM> is disposed in the vicinity of a bottom portion of the housing chamber <NUM>. The substrate <NUM> is formed to be laterally oblong plate-shaped and is arranged over an entire region of the housing chamber <NUM>.

The connector <NUM> is disposed on an upper face of a right end portion of the substrate <NUM>. The connector <NUM> is exposed to the outside of the casing <NUM> by removing the above-described slide cover <NUM>. To the connector <NUM>, a wire to be electrically linked to the external power supply is connected.

The power supply transformer <NUM> is disposed on the upper face closer to the left side of the substrate <NUM>. The power supply transformer <NUM> is configured to raise a voltage which is supplied via the connector <NUM>. In a left end portion of the power supply transformer <NUM>, a supply terminal portion <NUM> is provided. A feeder plate <NUM> of a discharge electrode <NUM> is fixed to the supply terminal portion <NUM> via a fastening member (screw <NUM>).

The earth terminal portion <NUM> is disposed on the upper face closer to the left side and on the rear side of the substrate <NUM>. An earth plate (not shown) of a counter electrode <NUM> is fixed to the earth terminal portion <NUM> via a fastening member (screw <NUM>).

As shown in <FIG> and <FIG>, the discharging processing unit <NUM> is generally arranged in the processing chamber <NUM>. The discharging processing unit <NUM> is configured to cause streamer discharging to purify air. The discharging processing unit <NUM> includes the insulation member <NUM>, the counter electrode <NUM>, the discharge electrode <NUM>, and a stabilizer <NUM>.

The insulation member <NUM> is formed of an insulative resin material and configures a supporting member which supports the discharge electrode <NUM> and the counter electrode <NUM> while insulating the same. The counter electrode <NUM> and the discharge electrode <NUM> are formed of a conductive metal material. The counter electrode <NUM> is electrically connected to an earth connection portion <NUM> to be grounded. The discharge electrode <NUM> is electrically connected to the voltage supply unit <NUM> and is supplied with a high voltage (e.g., <NUM> kV). When a voltage is supplied from the voltage supply unit <NUM> to the discharge electrode <NUM>, a streamer discharge is generated between both electrodes <NUM> and <NUM>. The stabilizer <NUM> is formed of a conductive resin material and is at the same potential of the discharge electrode <NUM>. The stabilizer <NUM> configures a conductive member (fixing member) for forming a stable electric field in the vicinity of the discharge electrode <NUM>.

As shown in <FIG>, the insulation member <NUM> is disposed at a bottom of the lower case portion <NUM>. As shown also in <FIG>, the insulation member <NUM> includes a joint portion <NUM>, a base portion <NUM>, a supporting portion <NUM>, and the lower partition wall <NUM>.

The joint portion <NUM> is disposed on the left side of the lower partition wall <NUM> in the processing chamber <NUM>. The joint portion <NUM> has a main body portion <NUM> and a connection portion <NUM>. The main body portion <NUM> is formed to have a rectangular solid form extending from a front edge to a rear edge of the lower case portion <NUM>. The connection portion <NUM> is formed continuously between a rear end portion of a right side surface of the main body portion <NUM> and the lower partition wall <NUM>.

The base portion <NUM> extends and protrudes from a middle part of a left side surface of the main body portion <NUM> in the front-rear direction. The base portion <NUM> has a pair of opposed wall portions standing upward from the bottom of the lower case portion <NUM> and extending parallel to each other, and a U-shaped joint wall portion linking distal ends of the opposed wall portions. The paired opposed wall portions are spaced apart from each other in the front-rear direction. This forms an arc portion 44a with an arc-shaped cross section in the base portion <NUM>. In the insulation member <NUM>, an oval groove <NUM> (recessed portion) is formed from the base portion <NUM> to the middle part of the main body portion <NUM>. The oval groove <NUM> is a laterally oblong elliptic column-shaped groove with a lower side blocked and an upper side opened.

The supporting portion <NUM> is arranged in a middle part of the oval groove <NUM> in the right-left direction and in the front-rear direction. The supporting portion <NUM> has a supporting portion main body <NUM> and a protrusion portion <NUM> (engagement portion) protruding upwardly from the supporting portion main body <NUM>. The supporting portion main body <NUM> is formed in a pillar shape with a transverse section having a laterally oblong oval shape.

The protrusion portion <NUM> is disposed in a middle part of the supporting portion main body <NUM> in the right-left direction and in the front-rear direction. Similarly to the supporting portion main body <NUM>, the protrusion portion <NUM> is formed in a pillar shape with a transverse section having a laterally oblong oval shape. A height, a width in the right-left direction, and a thickness in the front-rear direction of the protrusion portion <NUM> are all smaller than those of the supporting portion main body <NUM>. Accordingly, on an upper end surface of the supporting portion main body <NUM>, an oblong and oval annular placement surface <NUM> is formed around the protrusion portion <NUM>. The placement surface <NUM> is formed to be a generally horizontal plane. The supporting portion <NUM> supports the discharge electrode <NUM> and the stabilizer <NUM>.

The lower partition wall <NUM> extends from the front edge to the rear edge of the lower case portion <NUM>. The lower partition wall <NUM> is arranged closer to a front side of the lower case portion <NUM>.

As shown in <FIG> and <FIG>, the counter electrode <NUM> is supported by the insulation member <NUM>. The counter electrode <NUM>, which can be molded integrally, for example, with the insulation member <NUM>, is not limited thereto, but may be formed separately. In integral molding, the counter electrode <NUM> and the insulation member <NUM> are configured to be an integral unit by insert molding. The counter electrode <NUM> is formed to have such a flat plate-shape as to be located on the same plane (horizontal plane) as a whole. The counter electrode <NUM> includes a rectangular frame-shaped counter electrode main body 60a, and an earth plate (not shown) which extends rightward from a rear portion on the right side of the counter electrode main body 60a and is fixed to the earth terminal portion <NUM>.

The counter electrode main body 60a is configured with a first opposed plate <NUM>, a second opposed plate <NUM>, a first joint plate <NUM>, and a second joint plate (not shown) which are annularly combined. The first opposed plate <NUM> is located on a front side of the counter electrode main body 60a and extends in the right-left direction. The second opposed plate <NUM> is located on a rear side of the counter electrode main body 60a and extends in the right-left direction. Between the first opposed plate <NUM> and a front face of the base portion <NUM>, an oblong rectangular front side space portion <NUM> is formed. Between the second opposed plate <NUM> and a rear face of the base portion <NUM>, an oblong rectangular rear side space portion <NUM> is formed.

The first joint plate <NUM> is located on the left side of the counter electrode main body 60a to extend in the front-rear direction. The first joint plate <NUM> joins a left end of the first opposed plate <NUM> and a left end of the second opposed plate <NUM>. On an inner edge (right side) of the first joint plate <NUM>, an arc groove 63a with which the arc portion 44a of the base portion <NUM> engages is formed. The second joint plate is located on the right side of the counter electrode main body 60a to extend in the front-rear direction. The second joint plate joins a right end of the first opposed plate <NUM> and a right end of the second opposed plate <NUM>. The second joint plate is embedded in a top portion of the main body portion <NUM>.

As shown in <FIG> and <FIG>, the discharge electrode <NUM> is supported on a top portion of the insulation member <NUM>. The discharge electrode <NUM> is formed to be such a thin plate as to be located on the same plane (on the horizontal plane) as a whole. A thickness of the discharge electrode <NUM> is extremely small as compared with a thickness of the counter electrode <NUM>. The discharge electrode <NUM> includes an electrode supporting plate <NUM>, a plurality of discharging needles <NUM> and <NUM> supported in a side edge portion of the electrode supporting plate <NUM>, and a feeder plate <NUM> extending and protruding rightward from a front end portion of a right side of the electrode supporting plate <NUM>. The feeder plate <NUM> is connected to the supply terminal portion <NUM> via the screw <NUM>.

The electrode supporting plate <NUM> is arranged above the base portion <NUM>. The electrode supporting plate <NUM> extends in the right-left direction along the base portion <NUM>. At a center of the electrode supporting plate <NUM> (in a middle part of the electrode supporting plate <NUM> in a longitudinal direction and a width direction), a positioning hole <NUM> (opening hole), in which the protrusion portion <NUM> of the supporting portion <NUM> fits, is formed. The positioning hole <NUM> is formed to have a laterally oblong oval shape so as to correspond to a contour of the protrusion portion <NUM>. When the protrusion portion <NUM> fits in the positioning hole <NUM>, the electrode supporting plate <NUM> is disposed on the placement surface <NUM>. This maintains flatness of the electrode supporting plate <NUM>. In other words, the electrode supporting plate <NUM> is supported in a horizontal state by the placement surface <NUM>.

At a front edge of the electrode supporting plate <NUM>, the plurality of long needle-shaped or bar-shaped first discharging needles <NUM> are supported. The plurality of first discharging needles <NUM> are aligned at intervals along the front edge of the electrode supporting plate <NUM> to straightly and horizontally extend forward from the electrode supporting plate <NUM>. The first discharging needles <NUM> are arranged in parallel to each other. At a rear edge of the electrode supporting plate <NUM>, the plurality of long needle-shaped or bar-shaped second discharging needles <NUM> are supported. The plurality of second discharging needles <NUM> are aligned at intervals along the rear edge of the electrode supporting plate <NUM> to straightly and horizontally extend backward from the electrode supporting plate <NUM>. The second discharging needles <NUM> are arranged in parallel to each other. The electrode supporting plate <NUM> is formed to have an oblong shape extending in an alignment direction of the plurality of discharging needles <NUM> and <NUM>. This enables provision of numerous discharging needles <NUM> and <NUM> in the front and rear side edge portions of the electrode supporting plate <NUM>. The plurality of first discharging needles <NUM> and the plurality of second discharging needles <NUM> are generally coaxial in the front-rear direction, but may be arranged to be displaced in the right-left direction.

The first discharging needles <NUM> are parallel to the first opposed plate <NUM>, and the second discharging needles <NUM> are parallel to the second opposed plate <NUM>. A lower part of a tip of the first discharging needle <NUM> is opposed to the first opposed plate <NUM>, and a lower part of a tip of the second discharging needle <NUM> is opposed to the second opposed plate <NUM>.

The stabilizer <NUM> is arranged above the supporting portion <NUM> and the discharge electrode <NUM>. The stabilizer <NUM> includes a tubular wall portion <NUM> having a tubular shape, and a canopy portion <NUM> stretching out right and left and backward and forward from an upper end portion of the tubular wall portion <NUM>. In the tubular wall portion <NUM>, the protrusion portion <NUM> of the insulation member <NUM> fits. Accordingly, the stabilizer <NUM> is disposed on the top of the electrode supporting plate <NUM> to determine a relative positional relation between the stabilizer <NUM>, and the electrode supporting plate <NUM> and the counter electrode <NUM>.

A contour of the canopy portion <NUM> is formed to be a laterally oblong rectangular plate. With the protrusion portion <NUM> being fit in the tubular wall portion <NUM>, the canopy portion <NUM> is in a generally horizontal state. A front edge of the canopy portion <NUM> stretches out further frontward than the tips of the first discharging needles <NUM>. A rear edge of the canopy portion <NUM> stretches out further rearward than the tips of the second discharging needles <NUM>. In other words, a lower face of the canopy portion <NUM> forms a horizontal plane to be in parallel to the respective discharging needles <NUM> and <NUM> so as to follow the respective discharging needles <NUM> and <NUM>.

The air conditioning device <NUM> switches between a cooling operation and a heating operation. When the fan <NUM> of the air conditioning device <NUM> is operated, air in the room space S is sucked into the air passage 11a via the inside air duct <NUM>. This air passes through the prefilter <NUM>. The prefilter <NUM> collects relatively large dusts in the air.

The air having passed through the prefilter <NUM> passes through the discharge unit <NUM> (see <FIG>). Specifically, this air flows into the processing chamber <NUM> from the first vent <NUM> of the casing <NUM>. In the discharge unit <NUM>, a high voltage is supplied from the power supply transformer <NUM> of the voltage supply unit <NUM> to the discharge electrode <NUM>. As a result, streamer discharging progresses from the tip of each of the discharging needles <NUM> and <NUM> of the discharge electrode <NUM> toward the opposed plates <NUM> and <NUM> (see <FIG>). The high voltage is supplied also to the stabilizer <NUM> to be connected to the discharge electrode <NUM>. This stabilizes the streamer discharging directed from the discharging needles <NUM> and <NUM> to the opposed plates <NUM> and <NUM>.

When the discharging processing unit <NUM> generates a streamer discharge, activated species are resultantly generated in the air. As a result, harmful substances and odorous substances in the air are oxidized and decomposed by the activated species to purify the air. The air in the processing chamber <NUM> flows out of the casing <NUM> from the second vent <NUM> together with the activated species (see <FIG>) to pass through the catalyst filter <NUM>. The catalyst filter <NUM> adsorbs odorous substances and the like in the air. Decomposition of the adsorbed odorous substances by the activated species leads to reproduction of an adsorbent.

Thus purified air is heated or cooled by the heat exchanger <NUM>, and then supplied to the room space S via the air supply duct <NUM>. This leads to heating or cooling of the room space S, as well as to purification of room air.

Next, description will be made of a structure for suppressing adhesion of contaminants in the discharge unit <NUM> of the present embodiment.

As described above, in the discharge unit <NUM> of the present embodiment, the discharge electrode <NUM> and the counter electrode <NUM> are supported by one member (integral member), i.e., the insulation member <NUM>. In a structure in which the discharge electrode <NUM> and the counter electrode <NUM> are thus supported by the insulation member <NUM> as an integral supporting member, a continuous surface is formed from the discharge electrode <NUM> to the counter electrode <NUM>.

Specifically, for example, in <FIG>, the discharge electrode <NUM> disposed on the placement surface <NUM> of the supporting portion main body <NUM> (discharge electrode supporting portion <NUM>) of the insulation member <NUM> and the counter electrode <NUM> supported on the base portion <NUM> (counter electrode supporting portion <NUM>) are continuous by surfaces S1, S2, and S3 in a following manner. Specifically, the discharge electrode <NUM> and the counter electrode <NUM> are continuous by a surface S0 of the insulation member <NUM> including an outer surface S1 of the supporting portion main body <NUM>, an inner surface S2 of the base portion <NUM>, and a bottom surface S3 which links the outer surface S1 and the inner surface S2 at the bottom.

Accordingly, for example, in a discharging processing unit in a discharge unit of a reference example shown in <FIG>, when adhesion of contaminants to the surface S0 (S1, S2, and S3) of the insulation member <NUM> progresses, insulating properties between the discharge electrode <NUM> and the counter electrode <NUM> might be deteriorated.

Under these circumstances, the discharge unit <NUM> of the present embodiment is provided with an adhesion suppress structure for suppressing contaminants from adhering to the surface S0 of the insulation member <NUM>.

<FIG>, and <FIG> to <FIG> are sectional views showing the discharging processing unit <NUM> in the present embodiment. <FIG> shows a structure for suppressing adhesion of contaminants in a first structure example as defining the invention in the appended claims, <FIG> shows a structure for suppressing adhesion of contaminants in a second structure example, <FIG> shows a structure for suppressing adhesion of contaminants in a third structure example, and <FIG> shows a structure for suppressing adhesion of contaminants in a fourth structure example. Positions of these cross sections are positions taken along line A - A in <FIG>.

In the adhesion suppress structures shown in the first to fourth structure examples shown in <FIG>, and <FIG> to <FIG>, a wall portion <NUM> is provided which suppresses adhesion of contaminants M to the surface of the insulation member <NUM>. The wall portion <NUM> is provided on one side (inside) with respect to a discharge region D formed by the discharge electrode <NUM>. According to the invention, the wall portion <NUM> is provided closer to the side of the supporting portion main body <NUM> (the side of the discharge electrode supporting portion <NUM>) than the discharge region D.

In the present embodiment, the wall portion <NUM> is formed of an insulative material. The wall portion <NUM> may have a structure fixed to the insulation member <NUM> after being molded separately from the insulation member <NUM>, or may be integrally molded with the insulation member <NUM>. Additionally, the wall portion <NUM> may be formed of the same material as that of the insulation member <NUM> or formed of a material different from that of the insulation member <NUM>.

In the discharge unit <NUM> of the present embodiment, provision of the wall portion <NUM> as described above suppresses conductive contaminants M such as ammonium nitrate generated in the discharge region D and tobacco stains contained in room air from adhering to the surface S0 of the insulation member <NUM>. This suppresses deterioration in insulating properties between the discharge electrode <NUM> and the counter electrode <NUM> in the insulation member <NUM> having the surface S0 continuous from the discharge electrode <NUM> to the counter electrode <NUM>.

Although in the following, the first to fourth structure examples will be specifically described, the structure for suppressing adhesion of contaminants in the discharge unit <NUM> of the present embodiment is not limited to the following structure.

In <FIG>, the surface S0 of the insulation member <NUM> includes the outer surface S1 of the supporting portion main body <NUM> (discharge electrode supporting portion <NUM>), the inner surface S2 of the base portion <NUM> (counter electrode supporting portion <NUM>), and the bottom surface S3 which links the outer surface S1 and the inner surface S2 at the bottom of the supporting portion <NUM>. Then, the discharge electrode <NUM> and the counter electrode <NUM> are made continuous by the surface S0 (S1, S2, and S3) of the insulation member <NUM>.

In the first structure example shown in <FIG>, the wall portion <NUM> includes an extension portion <NUM> extending from an attachment portion P1 of the insulation member <NUM> to which the counter electrode <NUM> is attached to the side of the discharge electrode <NUM>. In the present embodiment, the attachment portion P1 is an upper end portion of the base portion <NUM> (counter electrode supporting portion <NUM>) or a part in the vicinity thereof as shown in <FIG> and <FIG>. The extension portion <NUM> is arranged in parallel to the counter electrode supporting portion <NUM> over the entire region where the plurality of discharging needles <NUM> (<NUM>) are provided. A gap is formed between a distal end portion (upper end portion) 91a of the extension portion <NUM> and the discharging needles <NUM> and <NUM>.

In the first structure example, the extension portion <NUM>, which extends from the attachment portion P1 to the side of the discharge electrode <NUM>, effectively functions as a barrier which suppresses the contaminants M generated in the discharge region D between the discharge electrode <NUM> and the counter electrode <NUM> from entering the surface S0 side of the insulation member <NUM>.

Additionally, provision of the extension portion <NUM> makes a distance L2 between the discharging needle <NUM> (<NUM>) of the discharge electrode <NUM> and the extension portion <NUM> of the wall portion <NUM> be shorter than a distance L1 between the discharging needle <NUM> (<NUM>) of the discharge electrode <NUM> and the opposed plate <NUM> (<NUM>) of the counter electrode <NUM>. As a result, the contaminants M such as ammonium nitrate generated in the discharge region D between the discharging needle <NUM> (<NUM>) of the discharge electrode <NUM> and the opposed plate <NUM> (<NUM>) of the counter electrode <NUM> and tobacco stains contained in room air are unlikely to pass through the gap between the discharge electrode <NUM> and the extension portion <NUM> of the wall portion <NUM>. This enhances an effect of suppressing adhesion of the contaminants M to the surface S0 of the insulation member <NUM>.

Additionally, the distance L2 between the discharging needle <NUM> (<NUM>) of the discharge electrode <NUM> and the extension portion <NUM> (upper end portion 91a) of the wall portion <NUM> is <NUM>% or more and <NUM>% or less of the distance L1 between the discharging needle <NUM> (<NUM>) of the discharge electrode <NUM> and the opposed plate <NUM> (<NUM>) of the counter electrode <NUM>. In other words, a ratio of the distance L2 to the distance L1 (L2/L1 × <NUM>%) is <NUM>% or more and <NUM>% or less.

When the distance L2 is less than <NUM>% of the distance L1, provision of the discharging needle <NUM> (<NUM>) and the extension portion <NUM> close to each other causes discharging to be generated easily. This makes it difficult to exhibit streamer discharging which is to be originally generated between the discharge electrode (<NUM>) and the counter electrode (<NUM>). By contrast, when the distance L2 exceeds <NUM>% of the distance L1, the contaminants M easily pass through the gap between the discharging needle <NUM> (<NUM>) and the extension portion <NUM>, so that it is difficult to effectively suppress adhesion of the contaminants M to the surfaces S1, S2, and S3 of the insulation member <NUM>. Therefore, the distance L2 is preferably <NUM>% or more and <NUM>% or less of the distance L1, more preferably <NUM>% or more and <NUM>% or less, and most preferably <NUM>%.

The graph of <FIG> shows an approximate curve of a relation between a ratio of the distance L2 to the distance L1 (the horizontal axis) and a durable- year of the discharge unit <NUM> (the vertical axis). As is clear from the graph, when the ratio of the distance L2 to the distance L1 is less than <NUM>% and when the same exceeds <NUM>%, a target durable-year (available period) of <NUM> years cannot be achieved. This is because of discharging generated between the discharging needle <NUM> (<NUM>) and the extension portion <NUM> or adhesion of contaminants to the surface of the insulation member <NUM> as described above, and maintenance is required before reaching <NUM> years of use. By contrast, by setting the ratio of the distance L2 to the distance L1 to be <NUM>% or more and <NUM>% or less, more than <NUM> years of durable-year can be achieved to enable continuous use of the discharge unit <NUM> for <NUM> years without maintenance. In particular, when the ratio of the distance L2 to the distance L1 is <NUM>% or more and <NUM>% or less, the durable-year exceeds <NUM> years, and when the ratio is <NUM>%, the durable-year reaches the maximum of <NUM> years.

Additionally, both of the distance between the discharging needle <NUM> and the extension portion <NUM> and the distance between the discharging needle <NUM> and the extension portion <NUM> may be <NUM>% or more and <NUM>% or less of the distance L1, but the present invention is not limited thereto. In other words, only the distance between the discharging needle <NUM> located on one side when viewed from the discharge electrode supporting portion <NUM> and the extension portion <NUM> may be within the above range, or only the distance between the discharging needle <NUM> located on the other side when viewed from the discharge electrode supporting portion <NUM> and the extension portion <NUM> may be within the above range.

Further, in the first structure example and according to the invention, the distal end portion (upper end portion) 91a of the extension portion <NUM> is located closer to the discharging needle <NUM> (<NUM>) of the discharge electrode <NUM> than to the opposed plate <NUM> (<NUM>) of the counter electrode <NUM>. Such location of the distal end portion (upper end portion) 91a of the extension portion <NUM> further enhances the effect of suppressing adhesion of the contaminants M to the surface S0 of the insulation member <NUM> as compared with location closer to the opposed plate <NUM> (<NUM>) of the counter electrode <NUM> than to the discharging needle <NUM> (<NUM>) of the discharge electrode <NUM>.

Additionally, in the present embodiment, since the insulation member <NUM> has the continuous recessed surface S0 formed by the above surfaces S1, S2, and S3, the surface area of the insulation member <NUM> is increased to enable a further increase in time until adhesion of the contaminants M to the surface S0 of the insulation member <NUM> causes conduction between the discharge electrode <NUM> and the counter electrode <NUM>.

The first structure example can be also used in combination with at least one of second to fourth structure examples to be described later.

In the second structure example shown in <FIG>, the wall portion <NUM> includes a sectioning portion <NUM> which sections a recessed inner space (i.e., the recessed inner space formed by the recessed portion <NUM> (oval groove <NUM>)) formed with the discharge electrode supporting portion <NUM> and the counter electrode supporting portion <NUM> into a first space 46A and a second space 46B. The first space 46A is located on a side of the discharge region D, and the second space 46B is located on the side opposite to the discharge region D with respect to the first space 46A (in the present embodiment, located on the side of the discharge electrode supporting portion <NUM>).

The sectioning portion <NUM> is a barrier standing from the bottom surface S3 of the supporting portion <NUM> of the insulation member <NUM> toward the discharging needle <NUM> (<NUM>) of the discharge electrode <NUM>. The sectioning portion <NUM> is arranged approximately in parallel to the discharge electrode supporting portion <NUM> over the entire region where the plurality of discharging needles <NUM> (<NUM>) are provided. A gap is formed between the sectioning portion <NUM> and the discharge electrode supporting portion <NUM>, and a gap is formed also between the sectioning portion <NUM> and the counter electrode supporting portion <NUM>. These gaps have substantially the same size. A gap is formed also between the distal end portion (upper end portion) 92a of the sectioning portion <NUM> and the discharging needles <NUM> and <NUM>.

In the second structure example, provision of the sectioning portion <NUM> enables an increase in a creepage distance from the discharge electrode <NUM> to the counter electrode <NUM> as indicated by a broken line in <FIG>.

Additionally, in the second structure example, since the sectioning portion <NUM> functions as a barrier, the contaminants M are more unlikely to reach the second space 46B as compared with the first space 46A. Therefore, it is possible to effectively suppress adhesion of the contaminants M to the surface forming the second space 46B (the surface S1 and a part of the surface S3) of the surface S0 of the insulation member <NUM>.

From the foregoing, in the second structure example, deterioration in the insulating properties between the discharge electrode <NUM> and the counter electrode <NUM> can be suppressed.

Additionally, provision of the sectioning portion <NUM> makes a distance L3 between the discharging needle <NUM> (<NUM>) of the discharge electrode <NUM> and the sectioning portion <NUM> of the wall portion <NUM> be shorter than the distance L1 between the discharging needle <NUM> (<NUM>) of the discharge electrode <NUM> and the opposed plate <NUM> (<NUM>) of the counter electrode <NUM>. As a result, the contaminants M such as ammonium nitrate generated in the discharge region D between the discharging needle <NUM> (<NUM>) of the discharge electrode <NUM> and the opposed plate <NUM> (<NUM>) of the counter electrode <NUM> and tobacco stains contained in room air are unlikely to pass through the gap between the discharge electrode <NUM> and the sectioning portion <NUM> of the wall portion <NUM>. This enhances an effect of suppressing adhesion of the contaminants M to the surface forming the second space 46B in the insulation member <NUM>.

Additionally, similarly to the first structure example, the distance L3 between the discharging needle <NUM> (<NUM>) of the discharge electrode <NUM> and the sectioning portion <NUM> (upper end portion 92a) of the wall portion <NUM> is <NUM>% or more and <NUM>% or less (preferably <NUM>% or more and <NUM>% or less, or <NUM>%) of the distance L1 between the discharging needle <NUM> (<NUM>) of the discharge electrode <NUM> and the opposed plate <NUM> (<NUM>) of the counter electrode <NUM>. This suppresses discharging generated due to the discharging needle <NUM> (<NUM>) and the sectioning portion <NUM> provided close to each other, and effectively suppresses the contaminants M generated in the discharge region from passing through the gap between the discharging needle <NUM> (<NUM>) and the sectioning portion <NUM> and entering the side of the second space 46B.

Additionally, both of the distance between the discharging needle <NUM> and the sectioning portion <NUM> and the distance between the discharging needle <NUM> and the sectioning portion <NUM> may be <NUM>% or more and <NUM>% or less of the distance L1, but the present invention is not limited thereto. In other words, only the distance between the discharging needle <NUM> located on one side when viewed from the discharge electrode supporting portion <NUM> and the sectioning portion <NUM> may be within the above range, or only the distance between the discharging needle <NUM> located on the other side when viewed from the discharge electrode supporting portion <NUM> and the sectioning portion <NUM> may be within the above range.

The second structure example can be also used in combination with at least one of the first structure example described above and third and fourth structure examples to be described later. Additionally, when using the first structure example and the second structure example in combination, a ratio of the distance L2, L3 to the distance L1 may be within the range of <NUM>% or more and <NUM>% or less in both of the first and second structure examples, or the ratio of the distance L2, L3 to the distance L1 may be within the range in only one of the examples.

In the third structure example shown in <FIG>, the wall portion <NUM> includes a plurality of projecting portions <NUM> provided on the surface of the insulation member <NUM>. Accordingly, in the third structure example, provision of the plurality of projecting portions <NUM> enables an increase in the surface area of the surface of the insulation member <NUM>. This enables a further increase in time until adhesion of the contaminants M to the surface of the insulation member <NUM> causes conduction between the discharge electrode <NUM> and the counter electrode <NUM>. In other words, a creepage distance on the surface of the insulation member <NUM> can be increased.

In specific example of <FIG>, the projecting portions <NUM> are provided on both the discharge electrode supporting portion <NUM> and the counter electrode supporting portion <NUM>. The projecting portions <NUM> provided on the discharge electrode supporting portion <NUM> project to the side of the counter electrode supporting portion <NUM>, and a gap is provided between distal end portions of the projecting portions <NUM> and the counter electrode supporting portion <NUM>. Additionally, the projecting portions <NUM> provided on the counter electrode supporting portion <NUM> project to the side of the discharge electrode supporting portion <NUM>, and a gap is provided between the distal end portions of the projecting portions <NUM> and the discharge electrode supporting portion <NUM>. In <FIG>, the projecting portions <NUM> provided on the discharge electrode supporting portion <NUM> and the projecting portions <NUM> provided on the counter electrode supporting portion <NUM>, which are located opposed to each other with an interval, may be provided at positions displaced from each other.

The projecting portions <NUM> may be provided only on either one of the discharge electrode supporting portion <NUM> and the counter electrode supporting portion <NUM>. Additionally, although the plurality of projecting portions <NUM> are provided in the specific example of <FIG>, only one projecting portion <NUM> may be provided.

In the present embodiment, although the projecting portions <NUM> have a plate-shape which extends approximately in parallel to the discharge electrode supporting portion <NUM> over the entire region where the plurality of discharging needles <NUM> (<NUM>) are provided, the shape is not limited thereto. Each projecting portion <NUM> may have, for example, a shape projecting in a bar-form.

Additionally, in the third structure example, the projecting portions <NUM> also function as a barrier which suppresses the contaminants M from moving in the inner space of the recessed portion <NUM> (oval groove <NUM>), i.e., the recessed inner space formed by the discharge electrode supporting portion <NUM> and the counter electrode supporting portion <NUM>.

The third structure example can be also used in combination with at least one of the first and second structure examples described above and a fourth structure example to be described later.

In the fourth structure example shown in <FIG>, the insulation member <NUM> has a plurality of hole portions <NUM> which pass through the insulation member <NUM>. The hole portions <NUM> are provided in both the counter electrode supporting portion <NUM> and a bottom portion <NUM> of the supporting portion <NUM>. Although an opening size of the hole portions <NUM> provided in the bottom portion <NUM> is larger than an opening size of the hole portions <NUM> provided in the counter electrode supporting portion <NUM>, the size is not limited thereto.

In the fourth structure example, part of air containing the contaminants M and having reached close to the surface of the insulation member <NUM> flows out of the insulation member <NUM> through the hole portions <NUM>. This enables reduction in an amount of adhesion of the contaminants M to the surface of the insulation member <NUM>.

The fourth structure example shown in <FIG> is preferably used in combination with at least one of the first structure example, second structure example and third structure example described above. <FIG> illustrates a case where the extension portion <NUM> (the first structure example) indicated by a chain double-dashed line is used in combination with the fourth structure example.

<FIG> is a schematic view showing another example of the air conditioning device <NUM> including the discharge unit <NUM> according to the embodiment of the present invention. The air conditioning device <NUM> shown in <FIG> is an air cleaner <NUM> for purifying air in a room space.

As shown in <FIG>, the air cleaner <NUM> includes a box-shaped air-conditioning casing <NUM>. Inside the air-conditioning casing <NUM>, an air passage 11a is formed. The air-conditioning casing <NUM> has an air inlet port 11b communicating with the air passage 11a, and an air outlet port 11c. Air sucked from the air inlet port 11b into the air-conditioning casing <NUM> flows through the air passage 11a to be blown out of the air-conditioning casing <NUM> from the air outlet port 11c.

In the air passage 11a, a prefilter <NUM>, a discharge unit <NUM>, a catalyst filter <NUM>, and a fan <NUM> are arranged sequentially from an upstream side (the air inlet port 11b side) of an air flow to a downstream side (the air outlet port 11c side).

The discharge unit <NUM> generates low-temperature plasma by streamer discharging, which is followed by generation of highly reactive activated species (high-speed electron, ion, radical, ozone, and the like) in the air. In the air cleaner <NUM> shown in <FIG>, the same discharge unit <NUM> as those shown in <FIG> can be used. Additionally, also the prefilter <NUM>, the catalyst filter <NUM>, and the fan <NUM> are the same as the corresponding members of the above-described air conditioning device <NUM> shown in <FIG>.

In the air cleaner <NUM>, when the fan <NUM> is operated, air in the room space is sucked into the air passage 11a through the air inlet port 11b. This air passes through the prefilter <NUM>. The prefilter <NUM> collects relatively large dusts in the air.

The air having passed through the prefilter <NUM> passes through the discharge unit <NUM>. In the discharge unit <NUM>, when a high voltage is supplied to the discharge electrode <NUM>, streamer discharging progresses from the tip of each of the discharging needles <NUM> and <NUM> of the discharge electrode <NUM> toward the opposed plates <NUM> and <NUM> of the counter electrode <NUM> (see <FIG>). When the discharging processing unit <NUM> generates a streamer discharge, activated species are resultantly generated in the air. As a result, harmful substances and odorous substances in the air are oxidized and decomposed by the activated species to purify the air.

The air having passed through the discharge unit <NUM> flows out of the discharge unit <NUM> together with the activated species to pass through the catalyst filter <NUM>. The catalyst filter <NUM> adsorbs odorous substances and the like in the air. The adsorbed odorous substances are decomposed by the activated species to reproduce the adsorbent. Thus purified air is supplied to the room space through the air outlet port 11c.

The present invention is not limited to the above embodiment, but defined by the appended claims.

Although the embodiment in which the discharge unit <NUM> is mounted in the air conditioning device <NUM> has been illustrated, the discharge unit <NUM> can be also mounted in a device other than the air conditioning device <NUM>.

Although the embodiment in which the discharge unit <NUM> is configured to have a streamer discharging system has been illustrated, discharging system is not limited to the streamer discharging, but may be other system of discharging.

The above embodiment will be outlined as follows.

The discharge unit of the present embodiment includes discharge electrode (which includes an electrode supporting plate, a plurality of discharging needles supported in a side edge portion of the electrode supporting plate and a feeder plate extending and protruding rightward from a front end portion of a right side of the electrode supporting plate), a counter electrode (configured with a first opposed plate and a second opposed plate) which is opposed to the discharge electrode, and an insulation member having a surface which is continuous from the discharge electrode to the counter electrode, in which a wall portion which is configured to suppress contaminants from adhering to the surface of the insulation member is provided on one side with respect to a discharge region formed by the discharge electrode.

In this configuration, provision of a wall portion on one side with respect to the discharge region formed by the discharge electrode suppresses conductive contaminants such as ammonium nitrate generated in the discharge region and tobacco stains contained in room air from adhering to the surface of the insulation member. This suppresses deterioration in insulating properties between the discharge electrode and the counter electrode in the insulation member having the surface continuous from the discharge electrode to the counter electrode.

In the discharge unit, the wall portion is provided closer to the side of the discharge electrode supporting portion than the discharge region. In the discharge unit, a distance between the discharge electrode and the wall portion is preferably shorter than a distance between the discharge electrode and the counter electrode.

In this configuration, by setting the distance between the discharge electrode and the wall portion to be shorter than the distance between the discharge electrode and the counter electrode, the contaminants such as ammonium nitrate generated in the discharge region between the discharge electrode and the counter electrode and tobacco stains contained in room air are unlikely to pass through the gap between the discharge electrode and the wall portion. This further enhances an effect of suppressing adhesion of the contaminants to the surface of the insulation member.

In the discharge unit, the distance between the discharge electrode and the wall portion is preferably <NUM>% or more and <NUM>% or less of the distance between the discharge electrode and the counter electrode.

When the distance between the discharge electrode and the wall portion is less than <NUM>% of the distance between the discharge electrode and the counter electrode, provision of the discharge electrode and the wall portion close to each other causes discharging to be generated easily. This makes it difficult to exhibit the original discharging performance between the discharge electrode and the counter electrode. By contrast, when the distance between the discharge electrode and the wall portion exceeds <NUM>% of the distance between the discharge electrode and the counter electrode, contaminants easily pass through the gap between the discharge electrode and the wall portion, so that it is difficult to effectively suppress adhesion of the contaminants to the surface of the insulation member. Accordingly, the distance between the discharge electrode and the wall portion is preferably <NUM>% or more and <NUM>% or less of the distance between the discharge electrode and the counter electrode, more preferably <NUM>% or more and <NUM>% or less, and most preferably <NUM>% in view of suppressing discharging between the discharge electrode and the wall portion, as well as effectively suppressing adhesion of the contaminants to the surface of the insulation member.

In the discharge unit, the wall portion includes an extension portion extending from a part, to which the counter electrode is attached, of the insulation member to a side of the discharge electrode, wherein a distal end portion of the extension portion is located closer to the discharging needle of the discharge electrode than to the opposed plate of the counter electrode.

In this configuration, the extension portion of the wall portion extends from the part to which the counter electrode is attached to the side of the discharge electrode, and thus effectively functions as a barrier which suppresses the contaminants generated in the discharge region between the discharge electrode and the counter electrode from entering the surface side of the insulation member.

In the discharge unit, the insulation member has a recessed-shape.

In the above-described configuration, provision of the wall portion enables adhesion of the contaminants to the surface of the insulation member to be suppressed. However, it is difficult to completely prevent adhesion of the contaminants and it is inevitable that the contaminants are gradually adhered to the surface of the insulation member with a lapse of time of use. Thus, in this configuration, since a surface area of the insulation member is increased because the insulation member has a recessed-shape, time until adhesion of the contaminants to the surface of the insulation member causes conduction between the discharge electrode and the counter electrode can be further increased.

In the discharge unit, the insulation member includes a discharge electrode supporting portion which supports the discharge electrode, and a counter electrode supporting portion which supports the counter electrode, and the wall portion may include a sectioning portion which sections a recessed inner space formed with the discharge electrode supporting portion and the counter electrode supporting portion into a first space on a side of the discharge region and a second space on a side opposite to the discharge region with respect to the first space.

In this configuration, the sectioning portion of the wall portion sections a recessed inner space formed by the discharge electrode supporting portion and the counter electrode supporting portion into the first space on a side of the discharge region and the second space on the side opposite to the discharge region with respect to the first space. The second space is located at the side opposite to the discharge region with respect to the first space on the side of the discharge region. Accordingly, since the sectioning portion functions as a barrier, the contaminants are more unlikely to reach the second space as compared with the first space. Therefore, in this configuration, since it is possible to effectively suppress adhesion of the contaminants to the surface forming the second space out of the surface of the insulation member, deterioration in insulating properties between the discharge electrode and the counter electrode can be suppressed.

In the discharge unit, the wall portion may include one or a plurality of projecting portions provided on the surface of the insulation member.

In this configuration, provision of one or a plurality of projecting portions enables an increase in the surface area of the insulation member. As a result, time until adhesion of the contaminants to the surface of the insulation member causes conduction between the discharge electrode and the counter electrode can be further increased.

In this discharge unit, the insulation member may have one or a plurality of hole portions which passes through the insulation member.

Claim 1:
A discharge unit (<NUM>) comprising:
a discharge electrode (<NUM>) including an electrode supporting plate (<NUM>), a plurality of discharging needles (<NUM>,<NUM>) supported in a side edge portion of the electrode supporting plate (<NUM>) and a feeder plate (<NUM>) extending and protruding rightward from a front end portion of a right side of the electrode supporting plate (<NUM>);
a counter electrode (<NUM>) which is opposed to the discharge electrode (<NUM>) and is configured with a first opposed plate (<NUM>) and a second opposed plate (<NUM>); and
an insulation member (<NUM>) having a surface, which is continuous from the discharge electrode (<NUM>) to the counter electrode (<NUM>),
wherein a wall portion (<NUM>), which is configured to suppress a contaminant from adhering to the surface of the insulation member (<NUM>) is provided on one side with respect to a discharge region formed by the discharge electrode (<NUM>),
wherein the wall portion (<NUM>) includes an extension portion (<NUM>) extending from a part of the insulation member (<NUM>) to which the counter electrode (<NUM>) is attached to a side of the discharge electrode (<NUM>),
wherein the insulation member (<NUM>) includes a discharge electrode supporting portion (<NUM>) which supports the discharge electrode (<NUM>),
wherein the wall portion (<NUM>) is provided closer to the side of the discharge electrode supporting portion (<NUM>) than the discharge region (D),
wherein a distal end portion (91a) of the extension portion (<NUM>) is located closer to the discharging needle (<NUM> or <NUM>) of the discharge electrode (<NUM>) than to the opposed plate (<NUM> or <NUM>) of the counter electrode (<NUM>),
wherein the insulation member (<NUM>) has a recessed-shape and includes a counter electrode supporting portion (<NUM>) which supports the counter electrode (<NUM>).