Filters

Abstract

To provide a filter which improves degree of freedom of cutting auxiliary line arrangement and can correspond to various installation objects.SOLUTION: A filter 1 is configured from a flat plate-like filter body 2. The filter body 2 comprises, as cutting auxiliary lines 6 by cutting along which an outer edge 3 of the filter body 2 can be formed, a first perforation 7 of which a contour shape is a regular square, and a plurality of circular arc-shaped second perforations 8. An interval between holes of the first perforation 7 is so set as be different from an interval between holes of the second perforation. By constituting in this manner, the ease of cutting the first perforation and the second perforation can be adjusted, and therefore, the possibility that one perforation is cut off carelessly is prevented when cutting one perforation. Consequently, the filter improves degree of freedom cutting auxiliary lines, and can correspond to various installation objects.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a filter, and more particularly to a flat filter. [Background technology]

[0002] Fig. 8 is a perspective view showing the outline of the external shape of a conventional natural exhaust system attached to a wall, and Fig. 9 is an end view of the IX-IX line shown in Fig. 8. In addition, (1) of Fig. 8 and Fig. 9 shows the cover in a closed state, and (2) shows the cover in an open state.

[0003] With reference to these figures, a natural exhaust system 61 is attached to a wall surface 63 in a room of a house or the like, and exchanges air within the room.

[0004] The natural supply and exhaust device 61 is composed of a natural supply and exhaust body 65 and a filter 81 for the ventilation port. The natural supply and exhaust body 65 includes a flat opening and closing cover 66, a rectangular flat surface 71 overlapping the opening and closing cover 66, a ventilation port 75 formed in the center of the flat surface 71, and a frame-shaped frame 74 extending from the entire outer edge of the flat surface 71 and fixed to the wall surface. The opening and closing cover 66 has a square flat plate shape with rounded corners 68, and is attached so as to face the flat surface 71 and close the frame 74. In addition, a shaft 78 that allows the operating rod 67 protruding from the center of the surface of the opening and closing cover 66 on the ventilation port 75 side to slide is formed in the center of the ventilation port 75, and is fixed by bridging the inner wall 76 of the ventilation port 75 with a reinforcing part 77.

[0005] When the shaft 78 and the operating rod 67 of the opening / closing lid 66 are engaged in the natural supply / exhaust main body 65, the engagement position of the shaft 78 with the operating rod 67 can be changed in multiple stages, thereby making it possible to adjust the movement distance of the opening / closing lid 66 toward the room and maintain it in that state. Also, by releasing the engagement between the shaft 78 and the operating rod 67, the opening / closing lid 66 can be removed from the natural supply / exhaust main body 65.

[0006] A filter 81 large enough to cover the ventilation hole 75 is detachably attached to the center of the flat surface 71. The filter 81 is composed of a nonwoven fabric 82 and a holding portion 83 that fixes the shape of the nonwoven fabric 82.

[0007] When the natural exhaust system 61 is not in use, as shown in (1) in Figures 8 and 9, the opening / closing lid 66 is in a closed state in contact with the flat surface 71 via the cushioning material 73, and no outside air enters or leaves the room.

[0008] On the other hand, when the natural exhaust system 61 is in use, as shown in (2) in Figures 8 and 9, the engagement between the operating rod 67 of the opening / closing lid 66 and the shaft 78 of the natural exhaust system 65 is adjusted to move the opening / closing lid 66 toward the room, and the opening / closing lid 66 is held in an open state with a gap at a certain distance from the frame 74 toward the room. This allows outside air to enter and exit the room through the ventilation opening 75, as shown by the arrow in Figure 9 (2). When the outside air flows into the room, the nonwoven fabric 82 of the filter 81 removes dust particles such as pollen contained in the outside air, allowing fresh air to be taken into the room.

[0009] When such a conventional natural exhaust ventilation system 61 is used continuously, the nonwoven fabric 82 of the filter 81 becomes dirty with dust, causing a problem that the filter performance deteriorates. This problem can be solved by replacing the filter 81, but in order to replace the filter 81, it is necessary to first remove the opening and closing lid 66.

[0010] FIG. 10 is a front view showing a schematic external appearance of a conventional natural exhaust system with the opening and closing cover removed.

[0011] Referring to the figure, filter 81 is detachably attached to the center of flat surface 71 that was covered by an opening / closing lid (not shown). Therefore, in order to replace filter 81, it is necessary to first remove the opening / closing lid. And to remove the opening / closing lid, it is necessary to release the engagement between operating rod 67 of opening / closing lid 66 and shaft 78 of natural intake / exhaust body 65 as shown in Figure 9 above, which is not easy for a general user to do.

[0012] Furthermore, even after the opening and closing cover is removed, the following problems still exist when replacing the filter 81.

[0013] FIG. 11 is a front view showing, in outline, the external shapes of the natural exhaust / supply body and the filter in the conventional natural exhaust / supply system shown in FIG. 10 with the filter removed, and FIG. 12 is a perspective view showing, in outline, the external shape of the natural exhaust / supply body shown in FIG. 11.

[0014] 1 and 2, vent hole 75 is formed in a cylindrical shape, and its inner walls 76 are reinforced by rod-shaped reinforcing portion 77 that spans between them in an X-shape. A shaft 78 is provided in the center of reinforcing portion 77.

[0015] Stoppers 79, formed by a portion of the inner wall 76 protruding into the vent 75, are disposed on the inner wall 76 of the vent 75 at four positions facing each other across the vent 75, on the indoor side of the reinforcing portion 77. In addition, mounting portions 72, formed by a portion of the flat surface 71 being recessed toward the vent 75 side, are formed at four positions between the stoppers 79.

[0016] On the other hand, the filter 81 is composed of the nonwoven fabric 82 and the holding portion 83 as described above. An opening frame portion 87 is formed in the center of the holding portion 83, and the shaft body 78 is configured to pass through the opening frame portion 87 when the filter 81 is attached to the natural supply and exhaust main body 65. The nonwoven fabric 82 is attached to one side of the holding portion 83 so that the inside of the opening frame portion 87 is open. Therefore, when replacing the filter 81, it is not possible to replace only the nonwoven fabric 82, but it is necessary to replace the entire filter 81 with a new one.

[0017] As described above, in the conventional natural exhaust system 61, the filter 81 must be a filter designed specifically for the natural exhaust system, with the outer frame shape of the holder 83 fitting the shape of the mounting part 72, and therefore it cannot be adapted to various models, i.e., it lacks model compatibility. This problem also occurs in natural exhaust systems that have an opening and closing lid without an operating rod or the like.

[0018] As a filter to address the above-mentioned problems, Patent Document 1 discloses a filter body having a flat plate shape made of an elastic body, the filter body having a thickness and size sufficient to fill the entire periphery of the gap between the opening / closing lid 66 and the frame 74 in the open state. The filter body has an opening in the center through which the operating rod 67 can be inserted, and has a slit that continues from the opening to the outer edge of the filter body, so that the filter body can be attached to the gap with the frame 74 when the opening / closing lid 66 is in the open state, thereby providing a filtering effect for outside air. [Prior art documents] [Patent documents]

[0019] [Patent Document 1] JP 2017-12979 A Summary of the Invention [Problem to be solved by the invention]

[0020] However, depending on the model of the natural exhaust system 61, the open / close lid 66 may have various shapes (including sizes) such as a rectangular shape (including a square shape) or a circular shape, and therefore even the filter of Patent Document 1 has no purpose for the outer edge of the filter body to match the open / close lid 66, leaving room for improvement in model compatibility. Also, depending on the model of the natural exhaust system 61, the outer edge of the filter body may not be matched to the open / close lid 66, but may be cut into a circular shape to match the shape of the ventilation opening 75 and attached to the ventilation opening 75 for use, and therefore a single filter is required to be compatible with a wide range of models.

[0021] Here, by providing cutting assistant lines such as slits, perforations, or pressed lines on the filter, it is possible to make it easier for the user to cut the filter into the desired shape and size by hand or with scissors. However, if many cutting assistant lines are provided to accommodate various shapes of the opening and closing lid 66, the density of the cutting assistant lines will increase, causing them to approach or cross each other, which can be inconvenient as one cutting assistant line is inadvertently cut when cutting the other cutting assistant line. For this reason, the arrangement of the cutting assistant lines has been limited so that they do not approach or cross each other.

[0022] In addition, filters are used not only for natural exhaust ventilation systems, but also for other installation targets, such as the vents of range hoods, etc. Therefore, there has been a demand for a filter that can be adapted to various installation targets by improving the degree of freedom in the arrangement of the cutting guide lines.

[0023] The present invention has been made to solve the above-mentioned problems, and has an object to provide a filter that improves the degree of freedom in arranging cutting assist lines and can be used in a variety of installation targets. [Means for solving the problem]

[0024] In order to achieve the above object, the invention described in claim 1 is a filter comprising a flat filter body, the filter body being provided with a cutting assistant line along which an outer edge of the filter body is formed by cutting the filter body, the cutting assistant line including a first perforation for forming a first outer edge and a second perforation for forming a second outer edge having a shape different from that of the first outer edge, and the spacing between the holes of the first perforation is set to be different from the spacing between the holes of the second perforation. The first perforation has a rectangular contour, and the second perforation has a circular contour and is disposed inside the first perforation. This is what is being done.

[0025] With this configuration, the ease of tearing of the first perforation and the second perforation can be adjusted. Also, the outer edge of the filter body can be rectangular or a relatively small circular shape.

[0028] Claim 2 The invention described is A filter comprising a flat filter body, the filter body being provided with cutting assistant lines along which an outer edge of the filter body is formed by cutting the filter body, the cutting assistant lines including a first perforation for forming a first outer edge and a second perforation for forming a second outer edge having a shape different from that of the first outer edge, the spacing between holes of the first perforation being set to be different from the spacing between holes of the second perforation, The first perforation has a rectangular outline, and the second perforation is a portion of a circle whose outline has a diameter longer than the length of one side of the first perforation and shorter than the length of the diagonal, the portion being located inside the first perforation.

[0029] When configured like this, The ease of tearing the first and second perforations can be adjusted. When the contour shape of the second perforation is extended, a point where it intersects with the contour shape of the first perforation is generated.

[0030] Claim 3 The invention described is as follows: 2 In the configuration of the described invention, the first perforation has a square contour shape, and the center position of the contour shape coincides with that of the second perforation.

[0031] When configured in this manner, an approximately right-angled triangular portion is formed inside the four corners of the contour shape of the first perforation, surrounded by the straight-line portion of the first perforation and the arc-shaped portion of the second perforation.

[0032] Claim 4 The invention described is as follows: 3In any one of the configurations of the invention described above, the cutting assistance line further includes a third perforation for forming a through hole penetrating through the thickness direction at the center of the filter body, and the third perforation is configured so that the arrangement of the perforations is asymmetrical.

[0033] With this configuration, the third perforation can be easily cut from either the left or right side.

[0034] Claim 5 The invention described is as follows: 4 In the configuration of the described invention, the third perforation has holes spaced apart such that the holes are spaced apart less than the holes of the second perforation.

[0035] With this configuration, the third perforation is easier to tear off than the second perforation.

[0036] Claim 6 The invention described is as follows: 5 In the configuration of the invention described in any one of the above, the tear assist line further includes another perforation arranged inside the first perforation and the second perforation.

[0037] In this manner, another outer edge of the filter body can be formed. Effect of the Invention

[0042] As explained above, the invention described in claim 1 allows the ease of cutting of the first and second perforations to be adjusted, preventing the risk of inadvertently cutting one perforation when cutting the other perforation. This improves the freedom of positioning of the cutting assistance lines, making it possible to accommodate a variety of installation targets. Furthermore, since the outer edge of the filter body can be formed into a rectangle or a relatively small circle, it can be adapted to be installed on rectangular or circular objects, improving model compatibility.

[0044] Claim 2 The invention described is The ease of cutting the first and second perforations can be adjusted, which prevents the risk of accidentally cutting one perforation when cutting the other perforation. This improves the freedom of positioning the cutting assistance lines, making it possible to accommodate a variety of installation targets.When the contour shape of the second perforation is extended, a point is created where it intersects with the contour shape of the first perforation. This makes it easier to cut out the desired perforation even if the contour shapes of such perforations are arranged so that they intersect on an extension line.

[0045] Claim 3 The invention described is as follows: 2 In addition to the effects of the invention described above, a substantially right-angled triangular portion is formed inside the four corners of the outline shape of the first perforation, surrounded by the linear portion of the first perforation and the arc-shaped portion of the second perforation, making it easier to cut out the desired perforation even in such a relatively complicated arrangement of perforations.

[0046] Claim 4 The invention described is as follows: 3 In addition to the effects of the invention described in any one of the above, the third perforation makes it easy to cut from either the left or right side, so that even a relatively small through hole can be easily formed.

[0047] Claim 5 The invention described is as follows: 4 In addition to the effects of the described invention, the third perforation is easier to cut than the second perforation, making it easier to form a small through hole in the center.

[0048] Claim 6 The invention described is as follows: 5 In addition to the effects of any one of the above, another outer edge of the filter body can be formed, improving model compatibility. [Brief description of the drawings]

[0051] [Figure 1] 1 is a front view showing a schematic shape of a filter according to a first embodiment of the present invention. [Diagram 2] 2 is a front view showing in more detail the configuration of the cutting auxiliary lines of the filter shown in FIG. 1. [Diagram 3] FIG. 2 is an enlarged view of part A shown in FIG. [Figure 4]FIG. 2 is an enlarged view of part B shown in FIG. [Diagram 5] 2A to 2C are schematic perspective views showing the filter shown in FIG. 1 cut along the cutting aid lines, where (1) is cut along a first perforation and (2) is cut along a second perforation. [Figure 6] 6A and 6B are schematic perspective views showing how the filter shown in FIG. 5(1) is attached to the natural exhaust system, in which (1) is before attachment and (2) is after attachment. [Figure 7] FIG. 7 is an end view of line VII-VII shown in FIG. 6. [Figure 8] FIG. 1 is a perspective view showing a schematic external shape of a conventional natural exhaust ventilation system attached to a wall surface, where (1) shows the cover in a closed state and (2) shows the cover in an open state. [Figure 9] FIG. 9 is an end view of line IX-IX shown in FIG. 8. [Figure 10] FIG. 1 is a front view showing a schematic external appearance of a conventional natural exhaust ventilation system with an opening / closing cover removed. [Figure 11] FIG. 11 is a front view showing the outline of the external shapes of the natural exhaust body and the filter in the conventional natural exhaust system shown in FIG. 10 with the filter removed. [Figure 12] 12 is a perspective view showing a schematic external shape of the natural intake and exhaust main body shown in FIG. 11. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0052] FIG. 1 is a front view showing a schematic shape of a filter according to a first embodiment of the present invention.

[0053] Referring to the figure, the filter 1 is composed of a flat filter body 2 made of a thick nonwoven fabric. The filter body 2 has an outer edge 3 of a square shape with each side measuring 165 mm before cutting as shown in Fig. 1, which corresponds to a relatively large square shape of an openable / closable cover or vent of a natural exhaust ventilation device (not shown). Furthermore, the filter body 2 has a high shape recovery property when the shape is deformed by an external force and then the external force is removed, and does not require a structure equivalent to the retaining portion of the conventional filter described above.

[0054] The filter body 2 also includes, in order from the outer edge 3 toward the inside (center) as auxiliary cutting lines 6 along which the outer edge 3 of the filter body 2 is formed, a square-shaped first perforation 7, a plurality of arc-shaped second perforations 8, a circular fourth perforation 10, and a circular third perforation 9. Each perforation of the filter body 2 is configured so that holes penetrating in the thickness direction and connection portions that form intervals between the holes appear alternately in a dashed line when viewed from the front (as viewed from above in the thickness direction of the filter body 2) as shown in Fig. 1, and the user can easily cut along these lines with hands, scissors, etc.

[0055] Further, in the filter body 2, a slit 13 that is linear in front view is formed so as to continue from the third perforation 9 to the outer edge 3. The slit 13 penetrates in the thickness direction.

[0056] The first perforation 7 has an overall rectangular shape when viewed from the front, i.e., a rectangular outline, and by cutting along the first perforation 7, the outer edge 3 of the filter body 2 becomes a smaller rectangular shape than before cutting, so that it can be used with natural exhaust and ventilation devices that have a relatively small opening / closing lid or air vent that is square shaped.

[0057] Next, the configuration of the second perforation 8 will be described.

[0058] FIG. 2 is a front view showing in more detail the configuration of the cutting auxiliary lines of the filter shown in FIG.

[0059] Referring to the figure, the contour shape of the second perforation 8 is a portion of an imaginary circle 15, a portion of which is drawn by a dashed line, that is located inside (at the center) of the first perforation 7. That is, since the diameter D of the imaginary circle 15 is longer than the length L1 of one side of the first perforation 7, the top, bottom, left and right portions of the imaginary circle 15 appear outside the first perforation 7 as drawn by the dashed line. In addition, since the diameter D is shorter than the length L2 of the diagonal of the first perforation 7, there are portions where the contour shape of the first perforation 7 intersects with the imaginary circle 15. In other words, when the contour shape of the second perforation 8 is extended, it is arranged to intersect with the contour shape of the first perforation 7.

[0060] In addition, the center positions of the contour shapes of the first perforation 7 and the second perforation 8 coincide at point C. Therefore, inside the four corners (part A shown in FIG. 1 ) of the contour shape of the first perforation 7, a substantially right-angled triangular part 11 surrounded by the straight-line parts of the first perforation 7 and the arc-shaped parts of the second perforation 8 is formed.

[0061] The relationship between the first perforation 7 and the second perforation 8 will be described.

[0062] FIG. 3 is an enlarged view of part A shown in FIG.

[0063] 1, the first perforation 7 is composed of a plurality of linear holes 18a, 18b. The interval between adjacent holes 18a, 18b, i.e., the distance S1 of the connection portion 19 located therebetween, is about 1 mm.

[0064] The second perforations 8 are formed of a plurality of arc-shaped holes 20a, 20b. The distance S2 of the connecting portion 21, which is the interval between the adjacent holes 20a, 20b, is about 6 mm.

[0065] In this way, the interval between the holes 18 of the first perforation 7 is set narrower than the interval between the holes 20 of the second perforation 8. Therefore, the first perforation 7 can be cut with less force because the ratio of the hole portion to the entire perforation is larger than that of the second perforation 8. In this way, the second perforation 8 is prevented from being inadvertently cut when the first perforation 7 is cut. This improves the degree of freedom in the arrangement of the cutting assistance lines, making it possible to accommodate various installation targets. The ratio of the distance S1 to the distance S2 (S1:S2) is preferably set in the range of 1:2 to 1:10, and more preferably in the range of 1:3 to 1:8.

[0066] As described above, there are locations where the contour shapes of the first perforation 7 and the second perforation 8 intersect on an extended line. Note that, in order to prevent hole 20a of second perforation 8 from merging with hole 18a of first perforation 7 when extended, the ends of both are close to each other across connecting portion 22. In this way, even when the contour shapes of the perforations are arranged to intersect on an extended line, it is easy to cut out the desired perforation.

[0067] Furthermore, as described above, a substantially right-angled triangular portion 11 is formed inside the four corners of the outline shape of the first perforation 7, surrounded by the straight line portion of the first perforation 7 and the arc-shaped portion of the second perforation 8. That is, when cutting out the first perforation 7, although it is a relatively complicated arrangement of perforations that gradually approaches the hole portion of the second perforation 8, it is easy to cut out only the first perforation 7.

[0068] When cutting along the second perforation 8, the straight portions of the first perforation 7 connecting the arc-shaped portions that make up the second perforation 8 are also cut, so that the outer edge 3 of the filter body 2 becomes approximately circular with a portion that is straight.

[0069] Next, the third perforation 9 will be described.

[0070] FIG. 4 is an enlarged view of part B shown in FIG.

[0071] 1 and 4, the third perforation 9 located at the center of the filter body 2 is formed such that the arc-shaped holes 23a to 23c are connected to form a circle as a whole. On the left side of the third perforation 9 in the front view shown in FIG. 4 (the left side with the slit 13 as the axis), there is one connection part 24a, which is the interval between the holes 23a and 23b, and on the right side, there are two connection parts 24b and 24c. In other words, the ratio of the holes 23 is set to be large on the left side and small on the right side. Therefore, since the third perforation 9 is easy to cut from the left side, the user can easily cut it from the left side by pressing the area partitioned by the third perforation 9 with, for example, the thumb of the right hand. Since the arrangement of the perforations of the third perforation 9 (the positional relationship of the holes 23a to 23c) is configured asymmetrically in this way, the third perforation 9 is easy to cut from either the left or right side, and a relatively small through hole can be easily formed.

[0072] Furthermore, the distance S3 of the connecting portion 24a, which is the distance between the holes 23a, 23b of the third perforation 9, is approximately 1 mm, which is set to be narrower than the distance between the holes of the second perforation 8. With this configuration, the third perforation 9 is easier to cut out than the second perforation 8, making it easy to form a small through hole even in the center where it is difficult to use scissors or the like.

[0073] Next, the fourth perforation 10 will be described.

[0074] 1, the fourth perforation 10 is disposed inside the above-mentioned first perforation 7 and second perforation 8, and has a circular outline. By including other perforations in addition to the first perforation 7 and second perforation 8 as the cutting assist lines 2 in this manner, another outer edge 3 of an even smaller circle can be formed for the filter body 2, improving model compatibility. In the first embodiment, the spacing between the holes of the fourth perforation 10 is set to the same distance as the distance S2, which is the spacing between the holes of the second perforation.

[0075] Next, FIG. 5 is a schematic perspective view showing the filter shown in FIG. 1 cut along the cutting aid lines, (1) being cut along the first perforation, and (2) being cut along the second perforation.

[0076] 1 and 5(1), filter 1 is formed by cutting filter body 2 along first perforation 7 described above in Fig. 1, and forming outer edge 3 in a square shape when viewed from the front. Filter body 2 is also cut along third perforation 9, and a through hole 4 is formed in the center. Filter 1 is approximately 20 mm thick and is suitable for natural exhaust ventilation equipment with a square-shaped opening / closing cover or vent.

[0077] 1 and 5(2), the filter 1 is formed by cutting the filter body 2 along the second perforation 8 described above in FIG. 1, and making the outer edge 3 have the above-mentioned generally circular shape when viewed from the front. Similarly, a through hole 4 is formed in the center of the filter body 2. In this case, the filter 1 is suitable for a natural exhaust system having a circular opening / closing cover or vent hole.

[0078] Next, a method for mounting the filter 1 on the natural exhaust system will be described.

[0079] FIG. 6 is a schematic perspective view showing how the filter shown in FIG. 5(1) is attached to the natural exhaust system, where (1) is the view before attachment and (2) is the view after attachment, and FIG. 7 is an end view of the VII-VII line shown in FIG. 6.

[0080] First, referring to FIG. 6(1), when the opening / closing lid 66 is in the open position, hold the filter 1 so that the slit 13 faces the operating rod 67 of the natural exhaust device 61, and begin installation by pushing the filter 1 into the gap between the frame 74 and the opening / closing lid 66 as indicated by the arrow 25 drawn with a dashed dotted line.

[0081] As it is pushed in, the slit 13 widens from the point where it comes into contact with the operating rod 67. Then, when the entire slit 13 passes through the operating rod 67, the through hole 4 of the filter 1 engages with the operating rod 67, and the slit 13 closes to restore its shape due to the shape-restoring properties of the nonwoven fabric fibers, completing the attachment to the natural exhaust device 61 as shown in Figure 6 (2). At this time, the operating rod 67 is inserted through the through hole 4, so the attachment state is stable.

[0082] When removing the filter 1 from the natural exhaust system 61, the slit 13 can be widened by pulling it in the opposite direction to the direction in which it was pushed in during installation, making it possible to easily remove and replace the filter.

[0083] As described above, the filter body 2 of the filter 1 is cut along the first perforation 8 (see Figure 1, etc.) so that, when the filter 1 is installed, the position of the outer edge 3 of the filter body 2 approximately coincides with the projected position of the opening / closing lid 66 onto the filter body 2.

[0084] Referring to Figure 7, when the filter 1 is installed, it has a thickness sufficient to completely seal the gap between the opening / closing lid 66 and the frame body 74 (the distance between the outer edge of the opening / closing lid 66 and the frame body 74). In addition, as described above, it is large enough to completely seal the gap between the opening / closing lid 66 and the frame body 74, so that it can reliably provide a filtering effect against the outside air flowing in through the ventilation hole 75.

[0085] Furthermore, the movement of the opening / closing lid 66 toward the room can be adjusted in multiple stages, and since the filter 1 has high shape recovery properties overall, the thickness of the filter 1 can be adjusted to fit the gap between the opening / closing lid 66 and the frame 74 for various natural exhaust / air supply devices, resulting in a stable installation state.

[0086] In the above first embodiment, the specific perforations are defined as the first, second, third and fourth perforations, but any of the perforations may be defined as the first, second, third or fourth perforations. In other words, for example, when a specific perforation formed in the filter body is defined as the first perforation and another perforation is defined as the second perforation, the relationship defined in the present invention may be satisfied.

[0087] In the first embodiment, the first perforation has a narrower hole interval than the second perforation, but the hole interval may be wider, i.e., the hole interval may be different. With this configuration, the ease of cutting the first perforation and the second perforation can be adjusted, so that when cutting one perforation, the other perforation is prevented from being inadvertently cut off. It is preferable to set the hole interval relatively narrow to make the outer perforation easier to cut, and to set the hole interval relatively wide to make the inner perforation more difficult to cut. Furthermore, if the hole interval is set to be wider in the order of the first perforation, the second perforation, and the fourth perforation, it is possible to control the perforations to be more difficult to cut in the order of the first perforation, the second perforation, and the fourth perforation.

[0088] Furthermore, in the first embodiment, the outline shape of the first perforation is a square, but it may be rectangular, circular, or other shapes. Also, the shape may be slightly modified, such as by rounding the ends.

[0089] Furthermore, in the first embodiment, the second perforation is circular and intersects with the first perforation, but the second perforation may have a circular outline and be disposed inside the first perforation. In this manner, the outer edge of the filter body can be made rectangular or a relatively small circle, so that the filter body can be adapted to rectangular or circular objects, improving model compatibility.

[0090] Furthermore, the second perforation may be a contour shape formed at a certain distance from the first perforation. In this case, the second outer edge when cut will be a similar shape to the first outer edge, but reduced or enlarged, so that it can be used for installation objects that differ only in size.

[0091] Furthermore, in the above first embodiment, the filter is attached to a specific natural exhaust system, but it can be adapted to various models of natural exhaust systems that have an openable / closable cover. The present invention can be similarly applied to other installation objects as well as natural exhaust systems. For example, a filter to be attached to a range hood can be adapted to various models by providing multiple types of perforations with different hole spacing.

[0092] Furthermore, in the first embodiment, the filter is made of a thick nonwoven fabric, but the filter may be made of other materials, such as an open-cell sponge.

[0093] Furthermore, in the above first embodiment, when the filter is installed, the operating rod is inserted into the through hole, but depending on the model of the natural intake and exhaust main body, there are some in which the shaft covers the operating rod and some in which the operating rod and shaft engage on the outer surface, so it is sufficient for the operating rod or shaft to be inserted into the through hole.

[0094] Furthermore, in the above first embodiment, the open / close cover is attached via an operating rod so as to cover the frame body, and is intended for a natural exhaust ventilation system configured to be freely movable from the frame body toward the room, but the present invention can also be applied to a natural exhaust ventilation system that does not have an operating rod, etc. and has an open / close cover that is installed at a position a predetermined distance away from the frame body. In this case, the same effect can be achieved even if the filter does not have an opening or a slit.

[0095] Furthermore, in the first embodiment described above, the opening / closing cover has a square flat plate shape with rounded corners, but the present invention can also be applied to an opening / closing cover having a square flat plate shape with unrounded corners. Therefore, the square flat plate shape in the present invention is used as a concept that includes a square flat plate shape with rounded corners.

[0096] Furthermore, in the first embodiment, the fourth perforation is formed as another perforation, but the fourth perforation does not have to be provided. Also, other perforations may be added, such as providing a fifth perforation in a circular or rectangular shape on the inside of the fourth perforation.

[0097] Furthermore, in the first embodiment described above, the first perforation and the second perforation each form an outer edge of the filter body having a specific shape, but the first outer edge formed by the first perforation and the second outer edge formed by the second perforation may each have another shape as long as they are different in shape. This includes, for example, the above-mentioned first perforation and second perforation having similar shapes. [Explanation of symbols]

[0098] 1. Filter 2. Filter body 3…Outer edge 4...Through hole 6...Cutting aid line 7…First perforation 8...Second perforation 9…3rd perforation 10...4th perforation 18, 20, 23...hole 19, 21, 22…Connection parts 61...Natural exhaust system 63…Wall 66…Opening and closing cover 75…Ventilation hole In addition, the same symbols in each drawing indicate the same or corresponding parts.

Claims

1. A filter having a flat filter body, The filter body includes a cutting assistant line along which an outer edge of the filter body is formed by cutting the filter body, The cutting assistance line includes a first perforation for forming a first outer edge and a second perforation for forming a second outer edge having a shape different from that of the first outer edge, The spacing between the holes of the first perforation is set to be different from the spacing between the holes of the second perforation; The first perforation has a rectangular contour shape, A filter, wherein the second perforation has a circular outline and is disposed inside the first perforation.

2. A filter having a flat filter body, The filter body includes a cutting assistant line along which an outer edge of the filter body is formed by cutting the filter body, The cutting assistance line includes a first perforation for forming a first outer edge and a second perforation for forming a second outer edge having a shape different from that of the first outer edge, The spacing between the holes of the first perforation is set to be different from the spacing between the holes of the second perforation; The first perforation has a rectangular contour shape, The second perforation is a portion of a circle whose contour shape is longer than the length of one side of the first perforation and shorter than the length of the diagonal thereof, the portion being located inside the first perforation.

3. The filter according to claim 2 , wherein the first perforation has a square contour, and the center position of the second perforation coincides with the contour shape.

4. The cutting assist line further includes a third perforation for forming a through hole penetrating through the center of the filter body in a thickness direction, The filter according to claim 1 , wherein the third perforations are arranged asymmetrically.

5. The filter according to claim 4 , wherein the third perforations are set such that the spacing between the holes is narrower than the spacing between the holes of the second perforations.

6. The filter according to claim 1 , wherein the tear assist line further includes another perforation arranged on an inner side than the first perforation and the second perforation.

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