Filter device

Abstract

To suppress lowering of the maintenance performance of a filter device.SOLUTION: A filter device 1 comprises: a mesh-shaped filter 6 having an upper filter 6U which is exposed to an outdoor space 2O while being oriented vertically upward, and a lower filter 6L which is exposed to the outdoor space 2O while being oriented vertically downward; a cylindrical duct 7 communicating with an indoor space 2I at one end 7I; and a box-shaped body 8 having an upper opening 8U being an opening to which the upper filter 6U is extended, a lower opening 8L being an opening to which the lower filter 6L is extended, and a duct opening 8D being an opening to which the other end 7O of the duct 7 is connected. In the filter 6, an upper region being at least a part of a region in which the upper filter 6U is extended is overlapped on a lower region being at least a part of a region in which the lower filter 6L is extended via only the internal space 8I of the body 8 in an upper face view.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a filter device for ventilation that exchanges air between indoors and outdoors. [Background technology]

[0002] As one type of filter device provided for ventilation, a technique is known in which a filter for collecting foreign matter is provided in a duct that connects the indoors and outdoors, and the filter prevents the intrusion of foreign matter from the outdoors into the indoors. For example, a device has been proposed in which a filter is installed inside a tube spaced apart from both ends of a cylindrical duct with one end located indoors and the other end located outdoors (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-107105 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in a device in which a filter is installed inside the duct, foreign matter from the outdoors may remain attached to the filter or remain inside the duct, which requires the removal of the foreign matter from inside the duct, which may lead to reduced maintainability. Therefore, there is room for improvement in preventing deterioration in the maintainability of the filter device.

[0005] The present invention has been devised in view of the above problems, and one of its objectives is to prevent deterioration in the maintainability of the filter device. However, in addition to this objective, another objective of the present invention is to achieve actions and effects derived from the configurations shown in the "Mode for Carrying Out the Invention" described later, which are actions and effects that cannot be obtained by conventional techniques. [Means for solving the problem]

[0006] The filter device disclosed herein has the following configurations (1) to (8). (1) a mesh-like filter including an upper filter exposed facing vertically upward with respect to an outdoor space and a lower filter exposed facing vertically downward with respect to the outdoor space; A cylindrical duct having one end communicating with an indoor space; a box-shaped body provided with an upper opening, which is an opening through which the upper filter is stretched, a lower opening, which is an opening through which the lower filter is stretched, and a duct opening, which is an opening to which the other end of the duct is connected, The filter is provided such that an upper region, which is at least a part of an area in which the upper filter extends, overlaps with a lower region, which is at least a part of an area in which the lower filter extends, only through the internal space of the body, in a top view. A filter device comprising:

[0007] (2) The body is closed in all areas except for the upper opening, the lower opening, and the duct opening. The filter device according to (1) above. (3) The duct has an upwardly sloping portion that is positioned vertically upward from the other end connected to the duct opening toward the indoor space. The filter device according to (1) or (2), (4) The body is provided with the duct opening oriented along a vertical direction, A plate-shaped baffle plate is provided extending from a vertically upper portion of the region surrounding the duct opening into the internal space in an eave-like manner. The filter device according to any one of (1) to (3) above, (5) An exhaust unit that forcibly exhausts air to the outdoor space, or an intake / exhaust unit having an intake unit that forcibly draws air from the indoor space, The filter device according to any one of (1) to (4) above, (6) The mesh of the upper filter is set finer than that of the lower filter. The filter device according to any one of (1) to (5), (7) The body is provided with the duct opening oriented along a horizontal direction adjacent to the lower opening, The duct extends vertically downward from the other end connected to the duct opening, a cylindrical internal duct protruding vertically upward from the duct opening, the upper end of which communicates with the internal space, and the lower end of which communicates with a cylindrical interior of the duct; an umbrella portion that is spaced apart from the upper end of the internal duct in the internal space and covers the upper end of the internal duct from above; The filter device according to any one of (1) to (6), (8) The upper filter is provided with a bleaching unit having at least one of a water sprinkling unit that sprays water on the upper filter and an irradiation unit that irradiates the upper filter with electromagnetic waves. The filter device according to any one of (1) to (7), Effect of the Invention

[0008] According to the present invention, deterioration in maintainability of the filter device can be suppressed. [Brief description of the drawings]

[0009] [Figure 1]FIG. 2 is a schematic diagram showing a filter device together with a building. [Diagram 2] FIG. 2 is an exploded perspective view showing the filter device. [Diagram 3] FIG. 13 is a schematic diagram showing a filter device according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, a filter device as an embodiment will be described. The filter device of the present embodiment is a device used for ventilation of a building. The term "ventilation" as used herein includes intake of air from the outside of a building to the inside of the building and exhaust of air from the inside of the building to the outside of the building. In addition, "ventilation" is not limited to natural ventilation that takes in and expels air without using a power source such as a fan or blower, but also includes forced ventilation that uses a power source such as a fan or blower.

[0011] The directions used in this embodiment are defined as follows. The direction in which gravity acts is defined as downward (shown as "D" in the figure), and the opposite direction of downward is defined as upward (shown as "U" in the figure). Up and downward are parallel to the vertical direction, and the direction perpendicular to the vertical direction is the horizontal direction. Downward can be rephrased as the vertically lower side, and upward can be rephrased as the vertically upper side. The expression "along a specified direction" such as the vertical or horizontal direction is not limited to a form parallel to the specified direction, but also includes a form slightly inclined relative to the specified direction. For example, a form inclined at an angle of 15°, 30°, or 45° relative to the specified direction is included in a form along the specified direction.

[0012] I. One embodiment In the following embodiment, the configuration of the filter device is described in items [1] and [2]. Item [1] provides an overview of a building to which the filter device is applied, and item [2] provides a detailed description of the filter device. Then, the actions and effects of the configurations of items [1] and [2] are described in item [3].

[0013] [1. Building with filter device installed] 1, the filter device 1 is installed in a building 2 that encloses an indoor space 2I. The building 2 may be called a factory or facility if a production line is installed in the indoor space 2I, or may be called a warehouse if works or products are stored in the indoor space 2I. The building 2 is provided with an erected wall 3 and a roof 4 covering the upper part. The wall 3 and the roof 4 separate an indoor space 2I and an outdoor space 2O of the building 2. In the building 2 illustrated here, a building-side duct 5 provided separately from the filter device 1 communicates with the indoor space 2I.

[0014] 1 shows an example in which a filter device 1 is attached to each of a wall 3, a roof 4, and a building-side duct 5. In this embodiment, three types of filter devices 10, 20, and 30 are illustrated as the filter device 1. The first filter device 10 is the simplest configuration of the filter device 1. The first filter device 10 illustrated in Fig. 1 is attached to the building-side duct 5 at three locations, and to the roof 4 at two locations in the left and right centers and one location on the left side, for a total of six locations.

[0015] The second filter device 20 is a filter device 1 in which a structure is added to the first filter device 10. The second filter device 20 illustrated in FIG. These first and second filter devices 10, 20 have their inlets and outlets for exchanging air with the indoor space 2I provided along the vertical direction, and are, so to speak, attached horizontally.

[0016] On the other hand, the third filter device 30 has an entrance for exchanging air with the indoor space 2I arranged horizontally, and is thus attached vertically. The third filter device 30 illustrated in FIG. 1 is attached to one location on the right side of the roof 4.

[0017] [2. Filter device] Hereinafter, the configuration of the filter device 1 common to the three types of filter devices 10, 20, and 30 will be described with reference to FIGS. The filter device 1 includes a mesh filter 6 exposed to the outdoor space 2O, a cylindrical duct 7 communicating with the indoor space 2I (see FIG. 1), and a box-shaped body 8 (a "box," so to speak) to which the filter 6 and duct 7 are attached and which has an internal space 8I.

[0018] The filter 6 is a mesh filter for removing foreign matter. This filter 6 is a so-called pre-filter, and since it is exposed to the outdoor space 2O, it is preferable that it be weather resistant, and it is preferable that its shape is such that foreign objects such as flying insects are less likely to become caught in the filter 6. For example, from the viewpoint of ensuring weather resistance, it is preferable to use a filter 6 made of a stainless steel material, and from the viewpoint of ensuring a shape that is less likely to trap foreign matter, it is preferable to use a plain-woven filter 6. One specific example of the filter 6 is a stainless steel mesh filter having a mesh of plain-woven stainless steel wires.

[0019] In addition, from the viewpoint of preventing clogging of the filter 6, it is preferable to set the mesh (density of the mesh) of the filter 6 to a predetermined lower limit density or higher, and from the viewpoint of ensuring the removal of foreign matter by the filter 6, it is preferable to set the mesh to a predetermined upper limit density or lower. Another viewpoint for setting the predetermined lower limit density is to set the size at which insects, which are one type of foreign matter, can be captured by the filter 6 (i.e., a size at which insects cannot pass through the filter 6). For example, it is preferable to set the predetermined lower limit density to 10 [mesh / inch].

[0020] In the present filter device 1, two types of filters 6U and 6L are provided as the filters 6, which will be described below. Upper filter 6U: A filter 6 arranged above the internal space 8I. Lower filter 6L: A filter 6 arranged below the internal space 8I.

[0021] The filters 6U and 6L illustrated here are arranged to extend in the horizontal direction. The filters 6U and 6L may have a common mesh, or may have different meshes. For example, the upper filter 6U may have a larger mesh (finer mesh) than the lower filter 6L. The filter device 1 is not provided with any filters other than the filters 6U and 6L, and no filters are provided inside the duct 7 or in the internal space 8I of the body 8.

[0022] The upper filter 6U is disposed facing upward and exposed to the outdoor space 2O. In other words, the outdoor space 2O is above the upper filter 6U, and the internal space 8I of the body 8 is below it. Since the upper filter 6U is exposed facing upward, it can be said that the upper filter 6U is disposed in a location exposed to sunlight, wind and rain. The lower filter 6L is disposed facing downward and exposed to the outdoor space 20. In other words, the outdoor space 20 exists below the downward-facing lower filter 6L, and the internal space 8I of the body 8 exists above it.

[0023] The duct 7 is a cylindrical portion that forms a path for air to flow between the internal space 8I of the body 8 and the indoor space 2I (see FIG. 1) of the building 2. That is, both ends 7I, 7O of the duct 7 communicate with the spaces 2I, 8I. Specifically, of both ends 7I, 7O of the duct 7, one end 7I communicates with the indoor space 2I (see FIG. 1), and the other end 7O communicates with the internal space 8I. Due to this form of communication, at least a portion of the path of the air flow passage connecting the spaces 2I, 8I is formed by the duct 7. The duct 7 is a portion provided outside the internal space 8I of the body 8, and is provided separately from the building-side duct 5 of the building 2, and therefore may be referred to as an "apparatus duct 7."

[0024] The body 8 is a framework to which the filter 6 is attached and to which the duct 7 is connected. The body 8 is provided with the following openings 8U, 8L, and 8D at the locations where the filter 6 and the duct 7 are attached. Upper opening 8U: Opening where upper filter 6U is installed Lower opening 8L: Opening where lower filter 6L is installed Duct opening 8D: an opening to which the other end 7O of the duct 7 is attached

[0025] Each of these openings 8U, 8L, and 8D is a space penetrating the body 8. The upper opening 8U is disposed at the top of the body 8, and the lower opening 8L is disposed at the bottom of the body 8. The duct opening 8D is disposed at any position of the body 8, such as the side or bottom. The entire area of ​​the body 8 is closed except for the openings 8U, 8L, and 8D. Specifically, if a peripheral wall-like portion erected in the vertical direction between the upper opening 8U and the lower opening 8L is defined as a side surface, when the duct opening 8D is provided on the side surface, the entire area of ​​the side surface except for the duct opening 8D is closed, and when the duct opening 8D is not provided on the side surface, the entire area of ​​the side surface is closed.

[0026] An upper filter 6U is stretched over the upper opening 8U so as to cover the entire area. Similarly, a lower filter 6L is stretched over the lower opening 8L so as to cover the entire area. Here, "stretched" means provided in a stretched state. The other end 7O of the duct 7 is connected to the duct opening 8D. In this manner, the other end 7O of the duct 7 communicates with the internal space 8I.

[0027] In the filter device 1 of this embodiment in which the filter 6, the duct 7, and the body 8 are provided as described above, an upper region and a lower region are provided so as to overlap each other when viewed from above. Upper region: at least a part of the region in which the upper filter 6U extends Lower region: at least a part of the region in which the lower filter 6L extends

[0028] In the filter device 1 of this embodiment, only the internal space 8I exists below the upper region and above the lower region. In other words, no structure or device that can be installed in the internal space 8I is provided below the upper region and above the lower region, and the upper region is provided so as to overlap with the lower region in a top view via only the internal space 8I. Next, the configuration of each of the three types of filter devices 10, 20, and 30 will be described.

[0029] [2-1. First filter device] First, the configuration of a first filter device 10 will be described with reference to FIGS. In the first filter device 10, a duct opening 8D oriented along the vertical direction is disposed on a side of the body 8. That is, in the first filter device 10, the duct opening 8D is provided in a peripheral wall-like portion (i.e., a side surface) erected along the vertical direction between an upper opening 8U and a lower opening 8L. One end 7I of a duct 7, the other end 7O of which is connected to this duct opening 8D, forms an entrance / exit for exchanging air with an indoor space 2I (see FIG. 1).

[0030] The duct 7 connected to the duct opening 8D is provided with an upwardly inclined portion 79 that is positioned upward from the other end 7O connected to the duct opening 8D toward the indoor space 2I (see FIG. 1). The upwardly sloping section 79 is positioned at least in the upstream portion of the path through which air flows, assuming that the internal space 8I side is the upstream side of the path through which air flows from the internal space 8I of the body 8 to the indoor space 2I of the building 2 (see Figure 1).

[0031] In addition, the filter 6 of the first filter device 10 exemplified here is provided in a planar shape along the horizontal direction. The first filter device 10 is provided such that nothing is provided in the internal space 8I of the body 8, and the entire area into which the upper filter 6U extends overlaps the entire area into which the lower filter 6L extends in a top view. That is, the entire area into which the upper filter 6U extends is the upper area, and the entire area into which the lower filter 6L extends is the lower area, and these upper and lower areas are disposed so as to be vertically separated from each other only via the internal space 8I of the body 8.

[0032] The first filter device 10 attached at six locations as illustrated in FIG. 1 will be further divided into the following three types of filter devices 11, 12, and 13, which will be described below. Duct filter device 11: Filter device 10 attached to building side duct 5 Forced ventilation filter device 12: Filter device 10 attached to the center of the roof 4 Roof filter device 13: Filter device 10 attached to the left side of the roof 4

[0033] The duct filter device 11 and the roof filter device 13 are natural ventilation devices that ventilate without using a power source. The forced ventilation filter device 12, as its name suggests, is a forced ventilation device that ventilates using a power source. In the duct filter device 11, one end 7I of the duct 7 is connected to the building-side duct 5. That is, the internal space 8I of the body 8 in the duct filter device 11 communicates with the indoor space 2I (see FIG. 1 ) via the duct 7 of the duct filter device 11 and the building-side duct 5 of the building 2. In the embodiment illustrated in FIG. 1 , three duct filter devices 11 are provided lined up one above the other.

[0034] The forced ventilation filter device 12 is a device equipped with an intake and exhaust unit 14 (power source) such as a fan or a blower. Fig. 1 shows an example in which the intake and exhaust unit 14 is disposed on the indoor space 2I side of the upward gradient section 79. The location where the intake and exhaust unit 14 is disposed as illustrated in Fig. 1 may be regarded as the inside of the duct 7 of the forced ventilation filter device 12, or may be regarded as a recess in the roof 4 of the building 2. In the roof filter device 13, one end 7I of the duct 7 is connected to the roof 4 of the building 2. In the embodiment illustrated in FIG. 1, the roof filter device 13 is attached to the side of a portion of the roof 4 of the building 2 that protrudes upward.

[0035] Hereinafter, the forced ventilation filter device 12 will be described in detail with reference to FIG. 1, focusing on the configuration of the intake and exhaust system. The intake and exhaust section 14 of the forced ventilation filter device 12 can be operated as an intake section that draws air into the indoor space 2I, or as an exhaust section that exhausts air to the outdoor space 2O, by setting the rotation direction of the fan and the blowing direction of the blower. Therefore, the intake and exhaust section 14 may be called either an intake section or an exhaust section.

[0036] The intake and exhaust section 14 is a power source that, when operating as an intake section, forcibly draws air into the indoor space 2I, and, when operating as an exhaust section, forcibly exhausts air to the outdoor space 2O. In addition, since sucking air into the indoor space 2I can be rephrased as supplying air to the indoor space 2I, the "air intake section" may be expressed as the "air supply section," and similarly, the "air intake and exhaust section 14" may be expressed as the "air supply and exhaust section 14."

[0037] By adjusting the operating state of the intake and exhaust unit 14, it is possible to set the flow rate of air passing through the filter 6 of the filter device 1. The flow rate of air set in this manner can be said to be the amount of air passing through the mesh of the filter 6 per unit time, or the wind speed passing through the filter 6. It is preferable that the air speed passing through the filter 6 is set according to the desired degree of positive pressure or negative pressure based on various specifications such as the size of the indoor space 2I, the number of filter devices 1 installed, the area of ​​the openings 8U and 8L provided for the filter 6, and the effective opening rate of the filter 6. Alternatively, the mesh density or wire diameter related to the effective opening rate of the filter 6 may be selected, the opening area may be set, or the number of filter devices 1 installed and the opening area for the filter 6 may be set, based on the desired degree of positive pressure in addition to the size of the indoor space 2I.

[0038] For example, when creating positive pressure, the wind speed at the mesh openings of the upper filter 6U of the forced ventilation filter device 12 is set so that more air is sucked in than the amount of air naturally discharged from the filter devices 1 other than the forced ventilation filter device 12. In this case, it is preferable that the speed of the wind passing through the upper filter 6U of the forced ventilation filter device 12 from the outdoor space 2O to the internal space 8I is set within a predetermined wind speed range.

[0039] The specified wind speed range is preferably set to above a specified lower limit wind speed in order to ensure the amount of air supplied to the indoor space 2I, and is preferably set to below a specified upper limit wind speed in order to prevent foreign matter such as insects from continuing to adhere to the upper filter 6U.

[0040] [2-2. Second filter device] As shown in FIG. 1, the second filter device 20 differs from the first filter device 10 in that the second filter device 20 is installed at a different location and is provided with a baffle plate 29, but the other configurations are similar to those of the first filter device 10. The baffle plate 29 is a plate-like member extending in a eaves-like manner from an upper part of the region surrounding the duct opening 8D into the internal space 8I. That is, in the second filter device 20, the baffle plate 29 is provided in the internal space 8I of the body 8. Functionally, the baffle plate 29 is a member that prevents foreign matter from entering the cylinder of the duct 7 through the duct opening 8D in the internal space 8I of the body 8.

[0041] As described above, a portion of the upper filter 6U extends above, and a portion of the lower filter 6L extends below, the baffle plate 29 installed inside the body 8. Therefore, in the second filter device 20, the upper region and the lower region that overlap in top view only through the internal space 8I are regions excluding the region that overlaps with the baffle plate 29 in top view, out of the extending regions of the filters 6U and 6L.

[0042] [2-3.Third filter device] As shown in FIG. 1, the third filter device 30 differs from the first filter device 10 and the second filter device 20 in that it is installed at a different location and does not have the above-mentioned upwardly sloping section 79, but instead has an internal duct 38 and an umbrella section 39. In the third filter device 30, a duct opening 8D oriented along the horizontal direction is disposed in the lower part of the body 8. A lower opening 8L is disposed adjacent to this duct opening 8D. In other words, the openings 8D and 8L are provided adjacent to each other and continuous with each other.

[0043] The duct opening 8D in the third filter device 30 is fitted with not only the duct 7 provided on the outside with respect to the internal space 8I, but also a cylindrical internal duct 38 that protrudes inward with respect to the internal space 8I. The other end 7O of the duct 7 is connected to the duct opening 8D, and the duct 7 extends downward from the duct opening 8D. A lower end 3L of an internal duct 38 is connected to the duct opening 8D, and the internal duct 38, which communicates with the inside of the cylinder of the duct 7, is provided protruding upward from the duct opening 8D. An upper end 3U, which is the end of the internal duct 38 protruding upward, communicates with the internal space 8I.

[0044] The duct 7 and the internal duct 38 may be provided separately from each other, or may be formed as an integrated cylindrical body. If the duct 7 and the internal duct 38 are an integrally formed cylindrical body, the duct 7 and the internal duct 38 are attached to the duct opening 8D by inserting this cylindrical body into the duct opening 8D.

[0045] An umbrella portion 39 that covers the upper end 3U of the internal duct from above is provided in the internal space 8I of the third filter device 30. The umbrella portion 39 is disposed away from the upper end 3U of the internal duct . In the embodiment illustrated here, the umbrella portion 39 is formed in a gable roof shape or a dome shape, and the straight internal duct 38 is entirely covered by the umbrella portion 39 in top view.

[0046] A part of the upper filter 6U extends upward relative to the internal duct 38 and the umbrella portion 39, and a part of the lower filter 6L extends downward relative to a region of the umbrella portion 39 excluding the region that overlaps with the internal duct 38 in a bottom view. Therefore, in the third filter device 30, the upper region and the lower region that overlap in a top view via only the internal space 8I are the region where the filters 6U, 6L extend excluding the region that overlaps with the umbrella portion 39 in a top view. Although FIG. 1 illustrates an example in which the upper filter 6U in the third filter device 30 extends horizontally, the upper filter 6U may be provided in a gable roof shape.

[0047] [3. Actions and Effects] Since the filter device 1 of the present embodiment has the above-mentioned configuration, it is possible to obtain the following actions and effects. (1) According to the filter device 1, air from the outdoor space 2O can be taken into the indoor space 2I by flowing from the upper opening 8U in which the upper filter 6U is stretched and the lower opening 8L in which the lower filter 6L is stretched, through the internal space 8I of the body 8, and from the other end 7O of the duct 7 at the duct opening 8D to one end 7I in that order. Conversely, air from the indoor space 2I can be flowed from one end 7I of the duct 7 to the duct opening 8D at the other end 7O, and then through the internal space 8I, and then discharged to the outdoor space 2O from the upper filter 6U stretched over the upper opening 8U and the lower opening 8L in which the lower filter 6L is stretched.

[0048] In this filter device 1, the filter 6 is stretched across both the upper opening 8U and the lower opening 8L, so that it is possible to ensure a larger extension area of ​​the filter 6 compared to a filter device in which a filter is stretched across only one of the upper opening and the lower opening. This makes it possible to ensure the flow rate of air taken in or exhausted through the filter 6 while suppressing the wind speed passing through the filter 6 stretched across both the upper opening 8U and the lower opening 8L.

[0049] According to the filter device 1 of the present embodiment, the upper region is provided so as to overlap the lower region in a top view with only the internal space 8I therebetween, and therefore the following action mechanisms a and b are achieved. Mechanism of action a: Insects and other foreign objects attached to the upper filter 6U are repeatedly dried out by exposure to sunlight and swollen by exposure to rain, which causes them to deteriorate and be naturally broken down. Mechanism of action b: Foreign matter that has been crushed by mechanism of action a to a size smaller than the mesh of the upper filter 6U passes through the mesh of the upper filter 6U by gravity and falls into the internal space 8I, then passes through the mesh of the lower filter 6L and is discharged again into the outdoor space 2O.

[0050] Due to the above-mentioned action mechanisms a and b, foreign matter adhering to the upper filter 6U is naturally removed, so that the maintainability of the filter device 1 can be ensured. In a conventional filter device in which a filter is provided inside a duct cylinder, maintenance work is required to remove foreign matter from the filter inside the duct cylinder. In contrast, the filter device 1 of the present embodiment can theoretically or structurally eliminate the need for maintenance work to remove foreign matter inside the duct cylinder. Therefore, deterioration in maintainability of the filter device 1 can be suppressed.

[0051] In addition, since the filter device 1 has filters 6 stretched over both the upper opening 8U and the lower opening 8L, rain falls from the upper filter 6U of the upper opening 8U through the internal space 8I onto the lower filter 6L of the lower opening 8L. Therefore, the lower filter 6L is naturally washed with water by rainfall, and even if foreign matter is attached to the lower filter 6L, the foreign matter can be washed off and removed by the rainwater.

[0052] Therefore, in a filter device in which a filter is installed only in the lower opening, foreign matter adhering to the filter in the lower opening is difficult to remove, whereas the filter device 1 can improve the maintainability of the lower filter 6L. (2) Furthermore, since all areas of the body 8 except for the openings 8U, 8L, and 8D are closed, it is possible to structurally prevent wind and rain from blowing into the duct opening 8D.

[0053] (3) The first and second filter devices 10 and 20 are provided with an upwardly inclined portion 79 located upward from the other end 7O connected to the duct opening 8D toward the indoor space 2I. Therefore, even if a foreign object enters the internal space 8I of the body 8, the foreign object is forced downward by gravity in the internal space 8I, and the intrusion of the foreign object from the internal space 8I into the upwardly inclined portion 79 of the duct 7 is structurally suppressed. For example, the intrusion of foreign objects such as insects, rain, and snow into the duct 7 is further suppressed by the upwardly inclined portion 79. In this way, the intrusion of foreign objects into the duct 7 is suppressed, and thus the maintainability of the first and second filter devices 10 and 20 can be suppressed from decreasing.

[0054] (4) The second filter device 20 is provided with a plate-shaped baffle plate 29 that extends in an eave-like manner from an upper part of the region surrounding the duct opening 8D into the internal space 8I. Therefore, even if rain or snow infiltrates into the internal space 8I from the upper filter 6U toward the duct opening 8D, the eave-shaped baffle plate 29 can structurally prevent foreign matter such as rain or snow from entering the duct opening 8D. This also contributes to preventing a decrease in the maintainability of the second filter device 20.

[0055] (5) The third filter device 30 is provided with the intake and exhaust section 14 which functions as an intake section and an exhaust section. The intake and exhaust section 14 operating as an exhaust section can forcibly exhaust air to the outdoor space 2O. The intake / exhaust section 14 operating as an intake section can forcibly draw air into the indoor space 2I.

[0056] (6) If the upper filter 6U is set to have a larger mesh (finer mesh) than the lower filter 6L, it is possible to prevent foreign matter that falls through the mesh of the upper filter 6U from being caught by the lower filter 6L and remaining in the internal space 8I of the body 8. This improves the ability to remove foreign matter, and further prevents deterioration in the maintainability of the filter device 1.

[0057] (7) The third filter device 30 has a cylindrical internal duct 38 that protrudes upward from the duct opening 8D and has an upper end 3U that communicates with the internal space 8I and a lower end 3L that communicates with the cylindrical interior of the duct 7, and is provided with an umbrella portion 39 that covers the upper end 3U of the internal duct 38 from above. Therefore, the umbrella portion 39 can structurally prevent foreign matter that has passed through the upper filter 6U and fallen from the internal duct 38 from entering the duct 7. Since the intrusion of foreign matter into the duct 7 is thus prevented, the maintainability of the third filter device 30 can be prevented from decreasing.

[0058] [II. Modifications] The above-described embodiment is merely an example, and is not intended to exclude various modifications and application of techniques not explicitly stated in the embodiment. Each configuration of the present embodiment can be modified in various ways without departing from the spirit of the embodiment. In addition, the configurations can be selected as necessary, and can be combined appropriately.

[0059] For example, as shown in FIG. 3, a filter device 1' according to a modified example may be provided with an exposed portion 40' that promotes crushing of foreign matter. 3 is provided with a water sprinkling section 41' that sprinkles water on the upper filter 6U', and an irradiation section 42' that irradiates the upper filter 6U' with electromagnetic waves. The water sprinkling section 41' can be a shower that sprinkles water on the upper filter 6U' from above, and the irradiation section 42' can be a light that irradiates the upper filter 6U' with electromagnetic waves from above.

[0060] The water sprinkling unit 41' sprinkles water on the foreign matter adhering to the upper filter 6U', and can be said to be a device for exposing the foreign matter to water. The irradiation unit 42' irradiates electromagnetic waves on the foreign matter adhering to the upper filter 6U', and can be said to be a device for exposing the foreign matter to electromagnetic waves. Since foreign matter such as insects attached to the upper filter 6U' swells when wet, the water sprinkling section 41' has a function of promoting the swelling of the foreign matter and can also be called a swelling promotion section. Since foreign matter such as insects attached to the upper filter 6U' deteriorates in the same way as sunburn when exposed to electromagnetic waves, the irradiation section 42' that irradiates the upper filter 6U' with electromagnetic waves has a function of promoting the deterioration of the foreign matter and can also be called a deterioration promotion section.

[0061] The bleaching section 40' having the water sprinkling section 41' and the irradiation section 42' can also be said to be a crushing promotion section that promotes the natural crushing of foreign matter by promoting the swelling and deterioration of the foreign matter. When the filter device 1' is installed in a place that is not exposed to sunlight or rain, it is preferable to provide the water sprinkling section 41' and the irradiation section 42' of the exposed section 40' to the filter device 1', since crushing is not easily promoted due to swelling or deterioration of the foreign matter.

[0062] According to the filter device 1' of the modified example, the crushing of foreign matter is promoted by the bleaching section 40' having the water sprinkling section 41' and the irradiation section 42', and the removal of foreign matter, including insects, attached to the upper filter 6U' can be improved. This also makes it possible to prevent the maintainability of the filter device 1' from decreasing. It is sufficient that the exposed section 40' is provided with at least one of the water sprinkling section 41' and the irradiation section 42'. For example, if the filter device is to be installed in a building in an area with little precipitation and many sunny days, a exposed section provided with only a water sprinkling section may be used. Conversely, if the filter device is to be installed in a building in an area with much precipitation and few sunny days, a exposed section provided with only an irradiation section may be used.

[0063] The filter is not limited to a flat shape along the horizontal direction, but may be a gable roof shape or a curved shape. Specific examples of the filter shape include a corrugated sheet with a wave-like or triangular wave cross section, a flat or curved shed roof shape, etc. From the viewpoint of allowing the accumulated snow to fall naturally from the upper filter, it is preferable to adopt an upper filter with an upwardly convex cross section such as a gable roof shape.

[0064] If an upper filter or lower filter having an uneven shape is used for the upper opening or lower opening, the extension area of ​​the upper filter or lower filter will be larger than the opening area of ​​the upper opening or lower opening. With such an upper filter or lower filter, the speed of wind passing through the upper filter or lower filter can be reduced without increasing the opening area of ​​the upper opening or lower opening (body size). In other words, the opening area of ​​the upper opening or lower opening (body size) can be reduced while maintaining the speed of wind passing through the upper filter or lower filter.

[0065] In addition, at least one of the duct filter device, roof filter device, second filter device, and third filter device exemplified in one embodiment may be provided with an intake and exhaust section like a forced ventilation filter device. Alternatively, a body may be employed in which an opening through which a filter is stretched is provided in at least a portion of the area other than the upper opening, the lower opening, and the duct opening. [Explanation of symbols]

[0066] 1,1′ Filter device 10 First filter device 11 Duct filter device 12 Filter device for forced ventilation 13 Roof Filter Device 14 Intake and exhaust section (intake section, exhaust section) 2. Building 20 Second filter device 29 Baffle Plate 2I Indoor space 2O outdoor space 3. Wall 30 Third filter device 38 Internal Duct 39 Umbrella section 3U top 3L bottom end 4. Roof 40' Bleached section 41′ Water spray part 42' Irradiation section 5. Building side duct 6 Filters 6U Upper Filter 6L Lower Filter 7 Duct 79 Uphill Section 7I One end 7O Other end 8. Body 8U upper opening 8L Lower opening 8D Duct opening 8I Interior space

Claims

1. a mesh-like filter including an upper filter exposed facing vertically upward with respect to an outdoor space and a lower filter exposed facing vertically downward with respect to the outdoor space; A cylindrical duct having one end communicating with an indoor space; a box-shaped body provided with an upper opening, which is an opening through which the upper filter is stretched, a lower opening, which is an opening through which the lower filter is stretched, and a duct opening, which is an opening to which the other end of the duct is connected, The filter is provided such that an upper region, which is at least a part of an area in which the upper filter extends, overlaps with a lower region, which is at least a part of an area in which the lower filter extends, only through the internal space of the body, in a top view. A filter device comprising:

2. The body is closed in all areas except for the upper opening, the lower opening, and the duct opening.

2. The filter device according to claim 1 .

3. The duct has an upwardly sloping portion that is positioned vertically upward from the other end connected to the duct opening toward the indoor space.

2. The filter device according to claim 1 .

4. The body is provided with the duct opening oriented along a vertical direction, A plate-shaped baffle plate is provided extending from a vertically upper portion of the region surrounding the duct opening into the internal space in an eave-like manner.

2. The filter device according to claim 1 .

5. An exhaust unit that forcibly exhausts air to the outdoor space, or an intake / exhaust unit having an intake unit that forcibly draws air from the indoor space, 2. The filter device according to claim 1 .

6. The mesh of the upper filter is set finer than that of the lower filter.

2. The filter device according to claim 1 .

7. The body is provided with the duct opening oriented along a horizontal direction adjacent to the lower opening, The duct extends vertically downward from the other end connected to the duct opening, a cylindrical internal duct protruding vertically upward from the duct opening, the upper end of which communicates with the internal space, and the lower end of which communicates with a cylindrical interior of the duct; an umbrella portion that is spaced apart from the upper end of the internal duct in the internal space and covers the upper end of the internal duct from above; 2. The filter device according to claim 1 .

8. The upper filter is provided with a bleaching unit having at least one of a water sprinkling unit that sprays water on the upper filter and an irradiation unit that irradiates the upper filter with electromagnetic waves.

8. The filter device according to claim 1, wherein the filter device is a filter unit.

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