Air purifiers, air conditioners, and ventilation fans

Abstract

To obtain an air purifier that eliminates the need for grounding work and prevents contamination of the mounting surface caused by an electric field extending from the air purifier to the mounting surface on which it is installed. [Solution] The air purifier 1 comprises a rectangular parallelepiped housing 10 having a first surface on which an air intake port 13 is provided for drawing in air, and a second surface different from the first surface on which an air outlet is provided for blowing out air, a blower 200, and a discharge-type electrostatic precipitator 120. The housing 10 has a stepped portion at the rear end of the side surface of the rectangular parallelepiped shape, and has a conductive component that is housed and mounted in the stepped portion on the side surface in the in-plane direction of the mounting surface, and contacts and covers the stepped portion from the outside of the housing 10. The conductive component does not cover the front surface 10e of the housing 10 and does not cover any area on the side other than the stepped portion.

Description

Technical Field

[0001] The present disclosure relates to an air purifier for purifying indoor air, an air conditioner having an indoor air purification function, and a ventilation fan.

Background Art

[0002] Conventionally, a method of collecting impurities in air using ions generated by discharge has been used. Patent Document 1 discloses an indoor unit of an air conditioner equipped with a function of removing and purifying impurities such as dust contained in indoor air. In the indoor unit disclosed in Patent Document 1, a conductor is provided around an ion generator, and by preventing the charging of the ion generator or the housing due to the discharge by the conductor, the charging of the wall surface where the indoor unit is installed is prevented, and the contamination of the wall surface due to the adhesion of dust to the wall surface is prevented.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the structure in which a conductor is provided around an ion generator as in the technology described in Patent Document 1 above, there is a problem that the amount of discharge from the conductor is limited and earthing work is required to connect the conductor to the ground. Further, in the technology described in Patent Document 1 above, since the electric field generated from the ion generator due to the potential of the charged ion generator cannot be sufficiently shielded, even if earthing work is performed, the effect of preventing the contamination of the wall surface is insufficient.

[0005] This disclosure has been made in view of the above, and aims to provide an air purifier that eliminates the need for grounding work and can prevent contamination of the mounting surface caused by an electric field extending from the air purifier to the mounting surface on which the air purifier is installed. [Means for solving the problem]

[0006] To solve the above-mentioned problems and achieve the objective, the air purifier according to this disclosure is an air purifier that is installed on a mounting surface in a room and purifies the air in the room. The air purifier comprises a rectangular parallelepiped housing having a first surface on which an air intake port is provided and a second surface different from the first surface on which an air outlet is provided; a blower housed in the housing that generates an airflow that draws in air from the intake port and blows air out from the outlet; and a discharge-type electrostatic precipitator housed in the housing that removes impurities from the airflow. The housing has a stepped portion at the rear end of the side surface of the rectangular parallelepiped shape, and has a conductive component that is housed and mounted in the stepped portion on the side surface in the in-plane direction of the mounting surface, and contacts and covers the stepped portion from the outside of the housing. The conductive component does not cover the front of the housing and does not cover any area other than the stepped portion on the side surface. [Effects of the Invention]

[0007] The air purifier described herein eliminates the need for grounding work and has the effect of preventing contamination of the mounting surface caused by an electric field extending from the air purifier to the mounting surface on which it is installed. [Brief explanation of the drawing]

[0008] [Figure 1] This figure shows the external appearance of the air purifier according to Embodiment 1, and is a perspective view of the air purifier seen from below. [Figure 2] This figure shows the external appearance of the air purifier according to Embodiment 1, and is a perspective view of the air purifier seen from above. [Figure 3]This is a schematic diagram showing the configuration of the air purifier according to Embodiment 1, and corresponds to the cross-section along line III-III in Figure 1. [Figure 4] A schematic diagram illustrating the principle of electrostatic precipitation in the electrostatic precipitator of the air purifier according to Embodiment 1. [Figure 5] This figure shows the external appearance of the air purifier according to Embodiment 2, and is a perspective view of the air purifier seen from below. [Figure 6] This figure shows the external appearance of the air purifier according to Embodiment 2, and is a perspective view of the air purifier seen from above. [Figure 7] This is a schematic diagram showing the configuration of the air purifier according to Embodiment 2, and corresponds to the cross-section along line VII-VII in Figure 5. [Figure 8] Rear view of the housing showing an example of the appearance when conductive components are arranged on the four sides of the housing of the air purifier according to Embodiment 2. [Figure 9] Enlarged cross-sectional view showing the second side and the area around the conductive components in the housing of the air purifier according to Embodiment 2. [Figure 10] Enlarged cross-sectional view showing a modified example of another conductive component of the air purifier according to Embodiment 2. [Figure 11] Enlarged cross-sectional view showing the second side of the housing and the area around other conductive components of a modified example of the air purifier according to Embodiment 2. [Figure 12] This figure shows the simulation results of the electric field strength on the wall surface where the air purifier according to Embodiment 2 is installed. [Figure 13] A schematic diagram showing the configuration of the air purifier according to Embodiment 3. [Figure 14] Enlarged cross-sectional view showing the area around the conductive component in the housing of the air purifier according to Embodiment 3. [Modes for carrying out the invention]

[0009] The air purifier, air conditioner, and ventilation fan according to the embodiment will be described in detail below with reference to the drawings. Note that, for ease of understanding, the scale of each component in the following drawings may differ from the actual scale. The same applies between drawings.

[0010] Embodiment 1. (Overall configuration of air purifier 1) Figure 1 is a diagram showing the external appearance of the air purifier 1 according to Embodiment 1, and is a perspective view of the air purifier 1 seen from below. Figure 2 is a diagram showing the external appearance of the air purifier 1 according to Embodiment 1, and is a perspective view of the air purifier 1 seen from above. Figure 3 is a schematic diagram showing the configuration of the air purifier 1 according to Embodiment 1, and is a diagram corresponding to the cross-section along line III-III in Figure 1. Note that in Figure 3, some hatching has been omitted for ease of understanding.

[0011] Air purifier 1 is an air purifier that can be installed on wall surfaces 500 and ceiling surfaces and cleans the indoor air environment by removing indoor air pollution. Wall surfaces 500 and ceiling surfaces are installation surfaces on which air purifier 1 is installed. Air purifier 1 has a housing 10 that constitutes the outer casing of air purifier 1. Housing 10 is composed of a housing body 11 and a front panel 12 and has a rectangular parallelepiped shape. Housing 10 is made of conductive resin and has a rectangular parallelepiped shape in which the depth dimension is smaller than the width dimension and height dimension.

[0012] The width direction of the air purifier 1 corresponds to the width direction of the housing 10 and corresponds to the X-axis direction in FIGS. 1 to 3. The width direction of the air purifier 1 can be equivalently referred to as the left-right direction. The depth direction of the air purifier 1 corresponds to the depth direction of the housing 10 and corresponds to the Y-axis direction in FIGS. 1 to 3. The depth direction of the air purifier 1 can be equivalently referred to as the thickness direction of the air purifier 1 or the thickness direction of the housing 10. The height direction of the air purifier 1 corresponds to the height direction of the housing 10 and corresponds to the Z-axis direction in FIGS. 1 to 3. When the air purifier 1 is installed on the wall surface 500, the height direction of the air purifier 1 is the up-down direction and is a direction parallel to the vertical direction. When the air purifier 1 is installed on the ceiling surface, the height direction of the air purifier 1 corresponds to a direction parallel to the horizontal direction. Further, in the air purifier 1, the side where the front panel 12 is located in the depth direction is the front side, and the side opposite to the side where the front panel 12 is located in the depth direction is the back side. The left-right direction is the left-right direction when the air purifier 1 is viewed from the front side.

[0013] The housing main body 11 is the first component that constitutes the housing 10 and has a rectangular parallelepiped shape with one side open. As shown in FIGS. 1 and 2, the housing 10 has an upper surface 10a, a lower surface 10b, a first side surface 10c, a second side surface 10d, a front surface 10e, and a back surface 10f. The first side surface 10c is the side surface on the left when viewed from the front side. The second side surface 10d is the side surface on the right when viewed from the front side. The first side surface 10c and the second side surface 10d are a pair of side surfaces that face each other in the width direction of the housing 10. The front surface 10e is constituted by the front panel 12. The housing main body 11 has an opening on one side on the front side, that is, the side corresponding to the front surface 10e of the housing 10. Incidentally, each of the upper surface 10a, the lower surface 10b, the first side surface 10c, the second side surface 10d, and the back surface 10f can also be regarded as the upper surface of the housing main body 11, the lower surface of the housing main body 11, the first side surface of the housing main body 11, the second side surface of the housing main body 11, and the back surface of the housing main body 11.

[0014] The air purifier 1 is installed on the wall surface 500 with its back surface 10f facing the wall surface 500. Specifically, the air purifier 1 is installed on the wall surface 500 with its upper surface 10a facing upward in the vertical direction, its lower surface 10b facing downward in the vertical direction, its front surface 10e and back surface 10f being parallel to the vertical direction, and its back surface 10f facing the wall surface 500. Therefore, when the air purifier 1 is installed on the wall surface 500, the back surface 10f of the housing 10 that faces the front panel 12 in the housing 10 becomes the opposing surface that faces the wall surface 500.

[0015] In the housing 10, a suction port 13, which is an opening for taking in indoor air into the interior of the housing 10, is formed on the first side surface 10c. That is, the housing main body 11 has the suction port 13 formed on the first surface of the housing main body 11, which is the side surface adjacent to the left side on the opened side. Also, in the housing 10, a blowout port 14, which is an opening for blowing out the air inside the housing 10 to the outside of the housing 10, is formed on the lower surface 10b. That is, the housing main body 11 has the blowout port 14 formed on the second surface of the housing main body 11, which is the side surface adjacent to the lower side on the opened side, and the blowout port 14 is formed so as to open downward in the vertical direction in the state of being installed on the wall surface 500.

[0016] The front panel 12 is a lid that covers the opened side of the housing main body 11 and is the second component that constitutes the housing 10. That is, the front surface of the air purifier 1 and the front surface 10e of the housing 10 are constituted by the front panel 12. The air purifier 1 can access each component housed inside the housing 10 when the front panel 12 opens to the front side.

[0017] The air purifier 1 is mounted to the wall 500 via a metal mounting bracket 400. The reasons why the mounting bracket 400 is necessary for mounting the air purifier 1 to the wall 500 are as follows: The first reason is to distribute the load applied to the back 10f and reduce the stress applied to the fastening part by widening the fixing range between the back 10f and the wall 500, thereby safely mounting the air purifier 1. The second reason is that in order to mount the air purifier 1 to the wall 500 in the correct position without tilting, it is necessary to precisely screw-fix the air purifier 1, but it is difficult to determine the screw fixing position while supporting the mass of the air purifier 1 during the installation work, so a lightweight part is used to precisely determine the fixing position of the air purifier 1. In other words, the reason why mounting brackets 400 are necessary for installing the air purifier 1 on the wall surface 500 is to facilitate safe and precise installation of the air purifier 1 without any concerns about wobbling or coming loose, and without any misalignment of the installation position or angle.

[0018] (Internal components of air purifier 1) The air purifier 1 comprises a dust collection unit 100, a blower 200, and a circuit unit 300 inside the housing 10. The dust collection unit 100, the blower 200, and the circuit unit 300 are housed in this order in the width direction of the housing 10, starting from the first side surface 10c where the intake port 13 is formed. That is, the dust collection unit 100, the blower 200, and the circuit unit 300 are housed in this order in the direction from the first side surface 10c to the second side surface 10d.

[0019] The air purifier 1 has several electrical components inside its casing 10, including a light-emitting diode (LED), an operation switch, a remote control receiver, a sensor, and a power supply for an electrostatic precipitator. Each of these electrical components is connected by electrical wiring to the low-voltage circuit board 302 of the circuit section 300, which will be described later.

[0020] The display LED functions as a display unit that shows various information related to the operation of the air purifier 1, such as the operating airflow of the air purifier 1 and the level of indoor air pollution. The operation switch is an operation unit for turning the power of the air purifier 1 on or off, the operating airflow of the air purifier 1, and switching between the automatic operation mode and the manual operation mode of the air purifier 1. The sensor is a detection unit that detects the air quality of the indoor air, such as dust in the indoor air, odor in the indoor air, and the level of carbon dioxide (CO2) pollution in the indoor air. The electrostatic precipitator power supply is a power supply unit that supplies high-voltage power to discharge the dust collection unit 100 to the electrostatic precipitator 120, which will be described later.

[0021] The dust collection unit 100 is located inside the housing 10, on the first side surface 10c in the width direction of the housing 10. That is, the dust collection unit 100 is housed inside the housing 10, on the side of the intake port 13 in the width direction of the housing 10. The dust collection unit 100 comprises a mesh filter 110, an electrostatic precipitator 120, and a deodorizing filter 130. The mesh filter 110, the electrostatic precipitator 120, and the deodorizing filter 130 are housed in this order in the width direction of the housing 10, starting from the first side surface 10c where the intake port 13 is formed. That is, the mesh filter 110, the electrostatic precipitator 120, and the deodorizing filter 130 are housed in this order in the direction from the first side surface 10c toward the second side surface 10d. Furthermore, it can be said that the mesh filter 110, the electrostatic precipitator 120, and the deodorizing filter 130 are housed in this order starting from the upwind side of the airflow drawn into the air purifier 1.

[0022] The mesh filter 110 removes impurities such as dust and dirt from the air drawn into the air purifier 1, and purifies the air drawn into the air purifier 1 by filtering it. When considering the pressure loss of the mesh filter 110, it is preferable to use a material with a coarse mesh. On the other hand, when considering the periodic maintenance of the downstream electrostatic precipitator 120, the mesh opening size of the mesh filter 110 is preferably about 0.5 mm in order to prevent electrical short circuits caused by dust bridging between the opposite electrodes of the electrostatic precipitator 120.

[0023] The electrostatic precipitator 120 removes impurities such as dust and dirt from the air drawn into the housing 10, thereby purifying the air drawn into the housing 10. The electrostatic precipitator 120 collects the fine particles by charging them with electric charge and attracting them to the dust collection electrode, thereby purifying the air drawn into the housing 10. Specifically, the electrostatic precipitator 120 generates ions by discharge through the application of a high voltage between the discharge electrode and the dust collection electrode, thereby charging the fine particles passing between the electrodes. The electrostatic precipitator 120 then collects the fine particles by attracting them to the dust collection electrode through the Coulomb force caused by the electric field between the electrodes.

[0024] Figure 4 is a schematic diagram illustrating the principle of electrostatic precipitation in the electrostatic precipitator 120 of the air purifier 1 according to Embodiment 1. The electrostatic precipitator 120 has a discharge electrode positive electrode 121 which is a discharge electrode, a discharge electrode negative electrode 122 which is a dust collection electrode, and an electrostatic precipitator power supply unit (not shown). The discharge-type dust collection device power supply is connected to the discharge electrode positive electrode 121 and the discharge electrode negative electrode 122 via wiring (not shown). In the electrostatic precipitator 120, when a high voltage is applied from the electrostatic precipitator power supply unit between the discharge electrode positive electrode 121 and the discharge electrode negative electrode 122, positively charged ions are generated by corona discharge in the discharge region 123, which is the region between the discharge electrode positive electrode 121 and the discharge electrode negative electrode 122. These positively charged ions combine with the surrounding dust particles 124, which then acquire a positive charge. These particles are then attracted to the negative electrode 122 of the low-potential discharge section, where they adhere and accumulate, thereby purifying the air. Therefore, the electrostatic precipitator 120 according to Embodiment 1 is a positive discharge type electrostatic precipitator.

[0025] The deodorizing filter 130 adsorbs and decomposes odors in the air drawn into the air purifier 1, thereby reducing the concentration of odor components in the air and deodorizing them through chemical changes in odor components into low-odor substances.

[0026] The blower 200 generates an airflow 45 that is drawn into the interior of the housing 10 from the intake port 13, passes through the dust collection section 100, and is blown out to the outside of the housing 10 from the outlet port 14. A centrifugal blower is used for the blower 200. The blower 200 has a fan 202 and a motor 203 housed inside the fan casing 201. The blower 200 draws in air from an intake port provided on the fan 202 side of the fan casing 201. A bell mouth 204 is provided on the surface of the fan casing 201 facing the front panel 12, which constitutes the intake port of the blower 200 and guides the airflow toward the fan 202 of the blower 200 after passing through the dust collection section 100. Furthermore, on the blower 200 side of the dust collection unit 100, an air passage wall 150 is provided, connected to the dust collection unit 100 side surface of the fan casing 201, to guide the airflow from the dust collection unit 100 towards the bell mouth 204. The bell mouth 204 can be described as an air guide that guides the airflow 45, which is drawn in from the intake port 13 and flows through the dust collection unit 100, into the blower 200. Air flows into the housing 10 from the intake port 13. The air that has flowed into the housing 10 is drawn into the fan 202 from the intake port of the blower 200 and blown out towards the outlet port 14.

[0027] The circuit unit 300 is a component for controlling the operation of the air purifier 1. The circuit unit 300 is located inside the housing 10, on the second side 10d side in the width direction of the housing 10. That is, the circuit unit 300 is housed inside the housing 10, on the side opposite the intake port 13, with the blower 200 in the width direction of the housing 10. The circuit unit 300 controls the operation of the electrical components mounted on the air purifier 1. The circuit unit 300 includes a control circuit for controlling the operation of the air purifier 1, i.e., a control circuit for controlling the motor 203 of the blower 200 and other electrical components, which are electrical components mounted on the air purifier 1. The circuit unit 300 includes a high-voltage circuit board 301, a low-voltage circuit board 302, and a sheet metal case 303.

[0028] The high-voltage circuit board 301 is a circuit board on which high-voltage circuits are mounted. The high-voltage circuit board 301 according to Embodiment 1 is connected to a power supply connection section and power is supplied from an external power supply. The high-voltage circuit board 301 functions as a power supply generation device that generates a drive power supply for driving the motor 203 of the blower 200, which has a relatively large drive current value among the electrical components mounted on the air purifier 1, using power supplied from an external power supply. The high-voltage circuit board 301 supplies the generated drive power supply to the motor 203.

[0029] The low-voltage circuit board 302 is a board on which low-voltage circuits are mounted. The low-voltage circuit board 302 according to Embodiment 1 is connected to a power supply connection section via a transformer (not shown), and power is supplied from an external power source. The low-voltage circuit board 302 functions as a power generation device that generates drive power for electrical components mounted on the air purifier 1, such as indicator LEDs, operation switches, sensors, and electrostatic precipitators 120, which have relatively small drive current values, using power supplied from an external power source. In other words, the low-voltage circuit board 302 functions as a power generation device that generates drive power for electrical components with a smaller drive current than the motor 203, using power supplied from an external power source. The low-voltage circuit board 302 supplies the generated drive power to electronic components such as indicator LEDs, operation switches, sensors, and electrostatic precipitators 120.

[0030] A high-voltage circuit is defined in the International Electrotechnical Commission (IEC) standard IEC-60335 as a circuit with a voltage exceeding 42.4V. A low-voltage circuit is defined in the IEC-60335 standard as a circuit with a voltage of 42.4V or less.

[0031] The sheet metal case 303 is made of metal plates and covers the front and sides of the high-voltage circuit board 301, protecting the high-voltage circuit board 301. It is also possible to cover the sheet metal case 303 from the front, back, and sides.

[0032] Next, the features of the air purifier 1 according to Embodiment 1, which is configured as described above, will be explained.

[0033] (Cabinet 10) As described above, the air purifier 1 is equipped with an electrostatic precipitator 120 inside the housing 10 that collects impurities from the air using ions generated by electrical discharge. When the air purifier 1 equipped with the electrostatic precipitator 120 is installed on a wall surface 500, if the resin housing 10 of the air purifier 1 is made of a general resin that does not have conductivity, the surface of the housing 10 will become charged, and an electric field will be generated between the housing 10 and the wall surface 500 on which the housing 10 is installed. This will cause dust to be attracted to and adhere to the wall surface 500 around the housing 10, resulting in the wall surface 500 becoming dirty.

[0034] The first reason the housing 10 becomes charged is that the electric field generated from the high-potential discharge electrode of the electrostatic precipitator 120 polarizes the surrounding area, causing the housing 10 to become charged.

[0035] Furthermore, a second cause of the housing 10 becoming charged is that some of the ions generated by the corona discharge in the electrostatic precipitator 120 flow through the housing 10 with the airflow 45, and in the process, ions adhere to the components of the air purifier 1, including the housing 10, causing them to become charged.

[0036] Here, if the ions generated by the corona discharge in the electrostatic precipitator 120 are positively charged ions, the housing 10 becomes positively charged. The wall surface 500 on which the air purifier 1 is installed is on the low-potential side connected to the earth, but if the housing 10 is made of a typical resin that does not conduct electricity, it is difficult for charge to be discharged from the housing 10 to the wall surface 500 which is the ground, and the charge of the housing 10 is maintained. Therefore, an electric field is generated from the positively charged housing 10 toward the wall surface 500, and impurities such as dust charged by the positive ions generated by the corona discharge adhere to the wall surface 500 by Coulomb force, causing the wall surface 500 to become dirty.

[0037] Therefore, in the air purifier 1, the outer casing 10 is made of a conductive material and is electrically connected to the wall surface 500 via a metal mounting bracket 400. Because the casing 10 is made of a conductive material and is electrically connected to the wall surface 500, which is the ground, the conductive casing 10 can shield the electric field generated from the electrostatic precipitator 120 and the electric field generated by the potential difference in the components caused by ions flowing downwind of the airflow 45 through the air passage inside the casing 10 from the wall surface 500. As a result, in the air purifier 1, the electric field extending from the casing 10 to the wall surface 500 is shielded by the conductive casing 10, and the occurrence of dirt on the wall surface 500 caused by the electric field can be prevented.

[0038] The side surface of the housing 10, which is made of a conductive material, can be considered a conductive part 10g. In other words, the air purifier 1 has a conductive part 10g on the side surface of the housing 10. As a result, the air purifier 1 can shield the electric field extending from the housing 10 to the wall surface 500 with the conductive part 10g, thereby preventing the generation of dirt on the wall surface 500 caused by the electric field.

[0039] Metal can be used as the conductive material for the housing 10. By constructing the housing 10 from metal, as described above, the housing 10 can shield the electric field that extends from the inside of the housing 10 to the wall surface 500 due to static charge inside the housing 10, thereby preventing the occurrence of fouling on the wall surface 500 caused by the electric field.

[0040] On the other hand, the housing 10 requires a shape with fine bumps and grooves to accommodate functions such as the intake port 13 and the outlet port 14, and considering weight reduction for improved product handling and manufacturing costs, it is generally made of resin. Therefore, in the air purifier 1, the housing 10 may be made of conductive resin.

[0041] A conductive resin is a resin that has conductive additives mixed into it and is therefore conductive. In other words, a conductive resin is a resin that contains conductive additives and is conductive.

[0042] Conductive resins have a degree of freedom in moldability due to the properties of the resin, making it possible to achieve shapes similar to those of general housings made of resins that do not contain conductive additives. Furthermore, conductive resins possess conductivity derived from conductive additives. Therefore, a housing 10 made of conductive resin can shield the electric field extending from the housing 10 to the wall surface 500. An example of a conductive additive is carbon nanoparticles.

[0043] Alternatively, the housing 10 may be constructed using a non-conductive resin that does not contain conductive additives, instead of a conductive resin, and conductivity may be added to the housing 10 by coating the surface of the non-conductive resin with a conductive paint. In other words, the housing 10 may be constructed by coating the outer surface of a non-conductive resin, which does not have conductivity, with a conductive paint.

[0044] As described above, in the air purifier 1 according to Embodiment 1, the housing 10 is made of a conductive material and is conductive, and by contacting and grounding with the wall surface 500, the generation of an electric field between the housing 10 and the wall surface 500 caused by ions generated by corona discharge in the electrostatic precipitator 120 can be suppressed. As a result, the air purifier 1 can prevent the accumulation of dirt on the wall surface 500. In other words, because the housing 10 of the air purifier 1 is made of a conductive material, dust can be prevented from adhering to the wall surface 500.

[0045] Furthermore, in the air purifier 1, the housing 10 itself is made conductive, and the housing 10 is grounded by making contact with the wall surface 500, so grounding work is unnecessary.

[0046] Therefore, the air purifier 1 according to Embodiment 1 has the effect of eliminating the need for grounding work and preventing dirt from being left on the wall surface 500 caused by the electric field extending from the air purifier 1 to the mounting surface on which the air purifier 1 is installed.

[0047] Embodiment 2. Figure 5 is a diagram showing the external appearance of the air purifier 2 according to Embodiment 2, and is a perspective view of the air purifier 2 seen from below. Figure 6 is a diagram showing the external appearance of the air purifier 2 according to Embodiment 2, and is a perspective view of the air purifier 2 seen from above. Figure 7 is a schematic diagram showing the configuration of the air purifier 2 according to Embodiment 2, and is a diagram corresponding to the cross-section along line VII-VII in Figure 5. Note that in Figure 7, some hatching has been omitted for ease of understanding. Also, in Figures 5 to 7, for the air purifier 2 according to Embodiment 2, the same reference numerals as those used for the air purifier 1 according to Embodiment 1 are used, and detailed explanations are omitted. Note that in the air purifier 2 according to Embodiment 2, the housing 10 is made of resin.

[0048] The conductive resins mentioned above are more expensive than general resins that do not contain conductive additives. Therefore, if the entire housing 10 is manufactured using conductive resin, the manufacturing cost of the air purifier will be higher than if the housing 10 were manufactured using general resin without conductive additives. For this reason, it is preferable that conductive material be used only in areas of the housing 10 where it is effective in preventing the accumulation of dirt on the wall surface 500.

[0049] In the housing 10, conductive material is used only in areas where it is effective in preventing the occurrence of dirt on the wall surface 500. Compared to manufacturing the entire housing 10 from conductive resin, this method reduces the manufacturing costs of the housing 10 and the air purifier while still achieving the effect of preventing dirt from occurring on the wall surface 500.

[0050] Therefore, the inventors measured the potential of the housing 10 and simulated the electric field strength around the housing 10. As a result, the inventors found that the electric field strength was high in the area where the housing 10 and the wall surface 500 were relatively close to each other on the wall surface 500 surrounding the housing 10, and that by arranging the conductive part 10g on the side surface of the housing 10, the electric field strength generated between the housing 10 and the wall surface 500 can be suppressed or prevented. Furthermore, the inventors found that in order to more reliably obtain the effect of preventing the occurrence of dirt on the wall surface 500 as described above, it is preferable that all four sides of the housing 10 be covered with the conductive part 10g.

[0051] Figures 5 to 7 show the state in which conductive components 20 are arranged on two of the four sides of the housing 10, namely the first side 10c and the second side 10d. Figures 5 to 7 also show the state in which the conductive components 20 are attached to the stepped-shaped portion 101 of the housing 10, which will be described later. With the air purifier 2 configured in this way, compared to the case in which the entire housing 10 is manufactured from conductive resin, it is possible to reduce the manufacturing costs of the housing 10 and the air purifier 2 while preventing the occurrence of dirt on the wall surface 500.

[0052] Figure 8 is a rear view of the housing 10, showing an example of the appearance when conductive components 20 are arranged on the four sides of the housing 10 of the air purifier 2 according to Embodiment 2. In Figure 8, the air purifier 2 is shown as viewed from the rear. Although Figure 8 is a plan view, the conductive components 20 are hatched for ease of understanding. Also, Figure 8 shows the housing 10 as viewed from the rear, with the conductive components 20 attached to the stepped-shaped section 101, which will be described later.

[0053] The conductive component 20 is made of a conductive material and is disposed on the side of the housing 10 from the outside of the housing 10 to cover that side. In other words, the conductive component 20 can be said to be a conductive part 10g. Therefore, the air purifier 2, in which the side of the housing 10 is covered with the conductive component 20, can be said to have a conductive part 10g on the side of the housing 10. As a result, the air purifier 2 can shield the electric field extending from the housing 10 to the wall surface 500 with the conductive part 10g, thereby preventing the generation of dirt on the wall surface 500 caused by the electric field.

[0054] Furthermore, when the sides of the housing 10 of the air purifier 2 are covered with conductive components 20, it is necessary that the functions of the intake port 13, which is an opening for drawing in room air into the housing 10, and the functions of the outlet port 14, which is an opening for blowing the air inside the housing 10 out to the outside, are not obstructed. For this reason, the conductive components 20 are provided with openings or notches corresponding to the shape and size of the intake port 13 and the outlet port 14 in the parts corresponding to the intake port 13 and the outlet port 14, or they are not placed on the sides of the parts corresponding to the intake port 13 and the outlet port 14. As a result, the conductive material placed on the sides of the housing 10 does not obstruct the functions of the intake port 13 and the outlet port 14.

[0055] Examples of conductive materials constituting the conductive component 20 include metals, conductive resins, and non-conductive resins coated with conductive paints.

[0056] However, metal has a metallic luster that is characteristic of metals, and its appearance does not harmonize with the resin that makes up the housing 10. For this reason, when conductive components 20 are placed on the side of the resin housing 10, the conductive components 20 made of metal stand out, and the aesthetic appearance of the air purifier 2 deteriorates. In order to maintain the visual harmony between the side of the housing 10 and the conductive components 20 when the side of the resin housing 10 is covered with conductive components 20 made of metal, one method is to paint the surface of the conductive components 20 with paint. However, when the surface of the conductive components 20 is painted, the conductivity of the surface of the conductive components 20 becomes extremely low, so the effect of using conductive material for the conductive components 20 is not fully obtained.

[0057] In contrast, by painting the surface of the conductive component 20 with conductive paint, the conductive component 20 can be given a visually harmonious appearance between the side surface of the resin housing 10 and the conductive component 20. As a result, the air purifier 2 can suppress the occurrence of dirt on the wall surface 500 while maintaining the aesthetic design of the air purifier 2, due to the conductivity of the conductive component 20 and the conductive paint.

[0058] Conductive paints are paints that have conductive additives mixed into them and possess conductivity. In other words, conductive paints are paints that contain conductive additives and are therefore conductive. An example of such paint is epoxy polyester paint. Examples of conductive additives include conductive carbon, metal powders, and metal oxide powders.

[0059] Furthermore, as shown in Figures 5 to 7, the housing 10 has a stepped portion 101 on its side surface that houses the conductive component 20 on the inside of the housing 10, relative to the side surface of the housing 10, in the in-plane direction of the wall surface 500. The conductive component 20 is attached to the stepped portion 101 on the side surface of the housing 10.

[0060] Figure 9 is an enlarged cross-sectional view showing the second side surface 10d and the area around the conductive component 20 of the housing 10 of the air purifier 2 according to Embodiment 2. Note that some hatching has been omitted in Figure 9 for ease of understanding. As shown in Figure 9, a stepped shape portion 101 is formed at the end of the second side surface 10d of the housing 10 on the rear surface 10f side.

[0061] The stepped portion 101 has a first stepped portion 102 and a second stepped portion 103 that bends and extends from the inner end of the first stepped portion 102 of the housing 10. In a cross section perpendicular to the back surface 10f, the stepped portion 101 has an L-shape in which the first stepped portion 102 and the second stepped portion 103 are connected.

[0062] The first stepped section 102 extends inward from a portion of the second side surface 10d in a direction perpendicular to the back surface 10f, in the in-plane direction of the back surface 10f of the housing 10 facing the wall surface 500 when the air purifier 2 is installed on the wall surface 500, and is parallel to the back surface 10f. In other words, the in-plane direction of the first stepped section 102 and the in-plane direction of the back surface 10f are parallel. The in-plane direction of the back surface 10f is parallel to the in-plane direction of the wall surface 500.

[0063] The second stepped portion 103 extends from the inner end of the housing 10 in the first stepped portion 102 toward the back surface 10f, bending in that direction, and is parallel to the second side surface 10d. In other words, the in-plane direction of the second stepped portion 103 and the in-plane direction of the second side surface 10d are parallel.

[0064] The conductive component 20 has a first conductive portion 21 that contacts the first stepped portion 102, and a second conductive portion 22 that bends and extends from one end of the first conductive portion 21 and contacts the second stepped portion 103. The conductive component 20 has an L-shape in a cross section perpendicular to the back surface 10f, where the first conductive portion 21 and the second conductive portion 22 are connected. The conductive component 20 is fixed to the stepped portion 101 by screwing the first conductive portion 21 to the first stepped portion 102 of the stepped portion 101 with a screw 40. Since the conductive component 20 is provided for the purpose of shielding electric fields, the first stepped portion 102 and the first conductive portion 21, and the second stepped portion 103 and the second conductive portion 22 do not necessarily have to be in contact, and gaps may exist.

[0065] Furthermore, in the air purifier 2, the first stepped section 102, which is the back side of the stepped section 101, is also covered by the conductive component 20, and the conductive component 20 is screw-fixed to the first stepped section 102. As a result, the screws 40 are less visible to the user in the air purifier 2, and the aesthetic design of the air purifier 2 is ensured.

[0066] Furthermore, the first side surface 10c of the housing 10 has the same configuration as the second side surface 10d described above.

[0067] Furthermore, in the air purifier 2, the conductive component 20 is in contact with the wall surface 500 when the air purifier 2 is installed on the wall surface 500. That is, as shown in Figure 9, the end portion 24 of the conductive component 20 in a direction perpendicular to the back surface 10f of the housing 10 is in contact with the wall surface 500 when the air purifier 2 is installed on the wall surface 500.

[0068] When the housing 10 becomes charged, an electric potential is generated within the housing 10.

[0069] In the air purifier 2, the conductive component 20 is grounded by bringing its end 24 into contact with the wall surface 500, thereby providing the conductive component 20 with an electric field shielding effect. As a result, the air purifier 2 can suppress the generation of an electric field between the housing 10 and the wall surface 500 caused by the potential generated when the housing 10 becomes charged, thereby suppressing the generation of dirt on the wall surface 500.

[0070] Figure 10 is an enlarged cross-sectional view showing a modified example of another conductive component 20a of the air purifier 2 according to Embodiment 2. Note that some hatching has been omitted in Figure 10 for ease of understanding. Figure 10 corresponds to Figure 9 and shows the other conductive component 20a being screw-fixed to the stepped portion 101. The other conductive component 20a differs from conductive component 20 in that it has a third conductive portion 23 that contacts the wall surface 500 and the back surface 10f of the housing 10 when the air purifier 2 is installed on the wall surface 500.

[0071] The other conductive component 20a has a third conductive portion 23, which ensures a larger contact area with the wall surface 500 when the air purifier 2 is installed on the wall surface 500 compared to the conductive component 20 without the third conductive portion 23.

[0072] Therefore, in the air purifier 2 using the third conductive part 23, the contact resistance between the housing 10 and the wall surface 500 can be reduced. As a result, in the air purifier 2 using the third conductive part 23, the electric field caused by the potential generated when the housing 10 becomes charged can be suppressed more effectively, and the generation of dirt on the wall surface 500 can be suppressed more effectively and reliably.

[0073] Figure 11 is an enlarged cross-sectional view showing the second side surface 10d and the area around other conductive parts 20a of the housing 10 of a modified example of the air purifier 2 according to Embodiment 2. In order to further improve the reliability of preventing the occurrence of dirt on the wall surface 500, it is preferable to use a metal mounting bracket 400 to fix the housing 10 to the wall surface 500.

[0074] When installing the air purifier 2 on a wall surface 500 using the mounting bracket 400, the mounting bracket 400 is first screw-fixed to the wall surface 500. At this time, the mounting bracket 400 is screw-fixed to the wall surface 500 so that it is in close contact with the wall surface 500. Next, the housing 10 is hooked onto the mounting bracket 400. After that, the housing 10 is screw-fixed to the mounting bracket 400. At this time, the housing 10 is screw-fixed so that the third conductive part 23 of the other conductive component 20a is in close contact and sandwiched between the back surface 10f of the housing 10 and the mounting bracket 400. In this case, it is preferable to make the mounting bracket 400 and the other conductive component 20a, or the wall surface 500 and the other conductive component 20a, in close contact by the tightening force of the screws.

[0075] Figure 12 shows the simulation results of the electric field strength on the wall surface 500 to which the air purifier 2 according to Embodiment 2 is installed. In the simulation shown in Figure 12, the conductive component 20 is not shown, but as in the case of Figure 9, the conductive component 20 is placed on the stepped shape portion 101 and is in contact with the wall surface 500.

[0076] The simulation was performed by changing the length of the conductive component 20 to several different values. The length of the conductive component 20 is the length from the wall surface 500 to the end of the conductive component 20 on the front surface 10e of the housing 10, in a direction perpendicular to the wall surface 500. Specifically, in condition 1, the length of the conductive component 20 was set to 0 mm. A length of 0 mm for the conductive component 20 means that the conductive component 20 is not placed. In condition 2, the length of the conductive component 20 was set to 18 mm. In condition 3, the length of the conductive component 20 was set to 28 mm. In condition 4, the length of the conductive component 20 was set to 38 mm. The dimension of the first stepped shape section 102 was set to 12 mm. The dimension of the second stepped shape section 103 was changed to match the dimension of the conductive component 20.

[0077] The simulation was performed with the discharge voltage of the corona discharge in the electrostatic precipitator 120, which is the primary cause of the first cause of the wall surface 500 becoming charged, set to 4kV to 10kV, and the charge of the housing 10, which is the primary cause of the second cause of the wall surface 500 becoming charged, set to 1kV. In the figure showing the simulation results in Figure 12, lighter hatching indicates a stronger electric field. Also, in the figure showing the simulation results in Figure 12, darker hatching indicates a weaker electric field. The representative point is the measurement point of the electric field strength on the wall surface 500, located 10 mm away from the side of the housing 10 on the surface of the wall surface 500.

[0078] As shown in Figure 12, it was found that the electric field strength at the wall surface 500 could be reduced by 50% in condition 2 compared to condition 1. Furthermore, it was found that as the simulation conditions were changed from condition 1 to condition 2, condition 3, and condition 4, that is, as the length of the conductive component 20 increased, the electric field strength at the representative point at the wall surface 500 decreased, and the shielding effect of the electric field increased. From this, it was found that by setting the length of the conductive component 20 from the wall surface 500 to 18 mm or more, the placement range of the conductive component 20 can be limited to an effective location to obtain the effect of preventing the occurrence of dirt on the wall surface 500, thereby efficiently suppressing the electric field generated between the housing 10 and the wall surface 500 and preventing the occurrence of dirt on the wall surface 500.

[0079] As described above, the air purifier 2 according to Embodiment 2 has the effect of preventing dirt buildup on the wall surface 500 on which the air purifier 2 is installed, similar to the air purifier 1 according to Embodiment 1, by eliminating the need for grounding work.

[0080] Furthermore, according to the air purifier 2, the placement range of the conductive component 20 is limited to an effective location to prevent the generation of dirt on the wall surface 500, thereby efficiently preventing the electric field generated between the housing 10 and the wall surface 500 and preventing the generation of dirt on the wall surface 500.

[0081] Embodiment 3. Figure 13 is a schematic diagram showing the configuration of the air purifier 3 according to Embodiment 3. For the air purifier 3 according to Embodiment 3, components similar to those of the air purifiers 1 and 2 according to Embodiments 1 and 2 are denoted by the same reference numerals as those of the air purifiers 1 and 2, and detailed explanations are omitted. In Embodiment 3, the air purifier 3 is installed in the ceiling 600 with a portion of the air purifier 3 embedded in the space above the ceiling through an opening 602 in the ceiling 600. Therefore, although the air purifier 3 basically has the same configuration as the air purifiers 1 and 2 described above, the arrangement of each component and the shape of the housing 10 differ from those of the air purifiers 1 and 2.

[0082] In the air purifier 3, a portion 10f1 of the back surface 10f of the housing 10 is used as a mounting section for installing the housing 10 to the ceiling 600. The air purifier 3 is installed to the ceiling 600 without using mounting brackets as used in Embodiment 1. Instead, the portion 10f1 of the back surface 10f of the housing 10 is fastened to the ceiling joists 603, which have high mechanical strength, from the inside of the air purifier 3 using screws 604. This installation method for the air purifier 3 is possible when the air purifier 3 is lighter than the air purifier 1.

[0083] Figure 14 is an enlarged cross-sectional view showing an enlarged view of the area around the conductive component 27 in the housing 10 of the air purifier 3 according to Embodiment 3. In Embodiment 3, the housing 10 of the air purifier 3 does not have the stepped portion 101 shown in Embodiment 2. The conductive component 27 according to Embodiment 3 has the same function as the conductive component 20 described above. The conductive component 27 has a fourth conductive portion 25 arranged perpendicular to the ceiling surface 601, and a fifth conductive portion 26 that bends and extends from one end of the fourth conductive portion 25 and is sandwiched between a part area 10f1 of the back surface 10f of the housing 10 and the ceiling surface 601. The ceiling surface 601 is the mounting surface on which the air purifier 3 according to Embodiment 3 is installed. The in-plane direction of the ceiling surface 601 is perpendicular to the in-plane direction of the side surface 10h of the housing 10. That is, the fourth conductive portion 25 is arranged parallel to the side surface 10h of the housing 10.

[0084] The conductive component 27 according to Embodiment 3 has an L-shape in which the fourth conductive portion 25 and the fifth conductive portion 26 are connected in a cross section perpendicular to the back surface 10f. The conductive component 27 is screw-fixed to the ceiling joist 603 together with a portion area 10f1 of the back surface 10f of the housing 10 by a screw 604. Therefore, the conductive component 27 according to Embodiment 3 has an L-shape comprising a fourth conductive portion 25 which is parallel to the side surface 10h of the housing 10, and a fifth conductive portion 26 which contacts the ceiling surface 601 and a portion area 10f1 of the back surface 10f of the housing 10 when the air purifier 3 is installed on the ceiling surface 601.

[0085] In the air purifier 3, the free end face of the fourth conductive part 25, which is positioned perpendicular to the ceiling surface 601, extends to the ends of the intake port 13 and outlet port 14 of the housing 10. Therefore, the air purifier 3 can suppress or prevent the occurrence of dirt on the ceiling surface 601 without compromising the aesthetic design of its appearance.

[0086] Embodiment 4. In the above, a configuration that can suppress or prevent the occurrence of dirt on the installation surface was described for air purifiers 1, 2, and 3 as shown in Figures 3, 7, and 13. The configuration shown in Figures 3, 7, and 13 can also be applied to air conditioners with air purification functions and ventilation fans with air purification functions. The same effect as described above can be obtained when the above-described configuration that can suppress or prevent the occurrence of dirt on the installation surface is applied to equipment such as air conditioners with air purification functions and ventilation fans with air purification functions.

[0087] The configurations shown in the above embodiments are examples only, and it is possible to combine them with other known technologies, combine different embodiments, and omit or modify parts of the configuration without departing from the gist of the invention. [Explanation of Symbols]

[0088] 1,2,3 Air purifier, 10 Housing, 10a Top, 10b Bottom, 10c First side, 10d Second side, 10e Front, 10f Back, 10g Conductive part, 10h Side, 11 Housing body, 12 Front panel, 13 Intake, 14 Outlet, 20,27 Conductive parts, 20a Other conductive parts, 21 First conductive part, 22 Second conductive part, 23 Third conductive part, 24 End, 25 Fourth conductive part, 26 Fifth conductive part, 40,604 Screw, 45 Airflow, 100 Dust collection part, 101 Stepped shape part, 102 First stepped shape part, 103 Second stepped shape part, 110 Mesh filter, 120 Electrostatic precipitator, 121 Discharge part positive electrode, 122 Discharge part negative electrode, 123 Discharge area, 124 Dust, 130 Deodorizing filter, 150 Air passage wall, 200 Blower, 201 Fan casing, 202 Fan, 203 Motor, 204 Bell mouth, 300 Circuit section, 301 High-voltage circuit board, 302 Low-voltage circuit board, 303 Sheet metal case, 400 Mounting hardware, 500 Wall surface, 501 Wall, 600 Ceiling, 601 Ceiling surface, 602 Opening, 603 Joist.

Claims

1. An air purifier that is installed on a surface inside a room and purifies the air inside the room, A rectangular parallelepiped housing having a first surface on which an air intake is provided, and a second surface different from the first surface on which an air outlet is provided for blowing out the air, A blower housed in the aforementioned casing, which draws in the air from the intake port and generates an airflow that blows out the air from the outlet, A discharge-type electrostatic precipitator housed in the aforementioned casing to remove impurities from the airflow, Equipped with, The aforementioned housing, The side of the rectangular parallelepiped has a stepped portion at the back end, The stepped portion has a conductive component that is housed and mounted on the inside of the side surface in the in-plane direction of the mounting surface, and contacts the stepped portion from the outside of the housing to cover the stepped portion. The conductive component shall not cover the front surface of the housing, nor shall it cover any area on the side surface other than the stepped portion. An air purifier characterized by [feature].

2. The conductive component is constructed separately from the housing by being made of metal, conductive resin, or non-conductive resin coated with conductive paint, and is detachably screw-fixed to the housing. An air purifier according to claim 1, characterized by the following:

3. The conductive component made of the aforementioned metal is coated with conductive paint on its outer surface. The air purifier according to claim 2, characterized by the following:

4. The conductive component is positioned to cover the four stepped portions of the housing. An air purifier according to claim 1, characterized by the following:

5. The conductive component is in contact with the mounting surface when the air purifier is installed on the mounting surface. An air purifier according to claim 1, characterized by the following:

6. The conductive component protrudes more than the back surface in the direction from the front surface toward the back surface of the housing, when the air purifier is installed on the mounting surface, and the back surface of the housing facing the mounting surface. The air purifier according to claim 5, characterized by the following:

7. The aforementioned stepped portion is In the state in which the air purifier is installed on the mounting surface, the back surface of the housing facing the mounting surface has a first stepped shape that extends inward from a portion of the side surface perpendicular to the back surface, bending inward from the middle of the side surface and parallel to the back surface, A second stepped portion extends from the inner end of the housing in the first stepped portion toward the rear surface, and is parallel to the side surface, It has an L-shape, The aforementioned conductive component is A first conductive portion that contacts the first stepped portion, A second conductive portion that contacts the second stepped portion, It has an L-shape, The first conductive portion is fixed to the first stepped portion. An air purifier according to claim 1, characterized by the following:

8. The conductive component has a third conductive portion that contacts the mounting surface and the back surface when the air purifier is mounted on the mounting surface. The air purifier according to claim 7, characterized by the following:

9. The aforementioned conductive component is When the air purifier is installed on the mounting surface, a fourth conductive part is provided which is parallel to the side surface, A fifth conductive part that contacts the mounting surface and the back surface of the housing when the air purifier is installed on the mounting surface, It has an L-shape, An air purifier according to any one of claims 1 to 6, characterized by the above.

10. An air conditioner that is installed on a mounting surface indoors and has an air purification function to purify the indoor air, A rectangular parallelepiped housing having a first surface on which an air intake is provided, and a second surface different from the first surface on which an air outlet is provided for blowing out the air, A blower housed in the aforementioned casing, which draws in the air from the intake port and generates an airflow that blows out the air from the outlet, A discharge-type electrostatic precipitator housed in the aforementioned casing to remove impurities from the airflow, Equipped with, The aforementioned housing, The side of the rectangular parallelepiped has a stepped portion at the back end, The stepped portion has a conductive component that is housed and mounted on the inside of the side surface in the in-plane direction of the mounting surface, and contacts the stepped portion from the outside of the housing to cover the stepped portion. The conductive component shall not cover the front surface of the housing, nor shall it cover any area on the side surface other than the stepped portion. An air conditioner characterized by the following.

11. A ventilation fan that is installed on a mounting surface indoors and has an air purification function to purify the indoor air, A rectangular parallelepiped housing having a first surface on which an air intake is provided, and a second surface different from the first surface on which an air outlet is provided for blowing out the air, A blower housed in the aforementioned casing, which draws in the air from the intake port and generates an airflow that blows out the air from the outlet, A discharge-type electrostatic precipitator housed in the aforementioned casing to remove impurities from the airflow, Equipped with, The aforementioned housing, The side of the rectangular parallelepiped has a stepped portion at the back end, The stepped portion has a conductive component that is housed and mounted on the inside of the side surface in the in-plane direction of the mounting surface, and contacts the stepped portion from the outside of the housing to cover the stepped portion. The conductive component shall not cover the front surface of the housing, nor shall it cover any area on the side surface other than the stepped portion. A ventilation fan characterized by the following.

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