Ventilation units and systems

Abstract

To provide a ventilation unit and a ventilation system that enables an inner frame to be smoothly attached and suppress damage to an inner surface of an outer frame.SOLUTION: Ventilation structure 2 is configured to suck and ventilate air in a room 3 by connecting an opening part 8 formed in a wall material 7 provided on a wall surface in the room and a ventilation duct 12. The ventilation structure 2 is provided between the opening part 8 of the wall material 7 and a ventilation duct side opening part 15A drawn and placed in the vicinity of the opening part 8, and the ventilation structure comprises: an outer frame 20 that communicates both opening parts 8 and 15A; an inner frame 30 to which a dust filter 33 is replaceably attached, which is attached to the outer frame 20 so that the outer frame can be freely taken in and out from a front side; and a lock mechanism 40 that locks the inner frame 30 with respect to the outer frame 20. The lock mechanism 40 comprises: a lock member 43 provided on the outer frame 20, in which a protruding piece 43A having an outer surface formed into a curved surface is elastically urged to freely appear and disappear; and a hole 45 that is provided in the inner frame 30 for receiving the protruding piece 43A of the lock member 43.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a ventilation unit and ventilation system (hereinafter also referred to as a ventilation structure) for a toilet or the like that is used by an unspecified number of people. [Background technology]

[0002] In toilets, there is a ventilation structure in which a ventilation opening is provided in the baseboard between the wall material that defines the interior of the toilet and the floor, this opening is connected to a ventilation duct via a branch pipe, the other end of the ventilation duct is connected to the outdoors, and the air is forcibly exhausted by a ventilation fan (see, for example, Patent Document 1).

[0003] In this type of ventilation structure, a ventilation box is connected to the open end of the branch pipe, and the ventilation box is positioned on the back side to match the shape of the opening in the baseboard. The ventilation box is equipped with a dust-proof mesh. Over time, dust accumulates in the mesh, reducing ventilation performance. Therefore, if a dust-clogging mesh is discovered during maintenance and inspection, the ventilation box is removed and replaced. However, to replace the mesh, the toilet must first be stopped from use and the baseboard removed. Then, the ventilation box is detached from the end of the branch pipe and the mesh of the ventilation box is replaced. After the replacement, the ventilation box with the new mesh attached is connected to the branch pipe, and the baseboard is reinstalled in its original position, completing the replacement process. This results in the problem of the time-consuming replacement process, and the toilet cannot be used during the replacement process.

[0004] Meanwhile, a ventilation unit (ventilation box) is known in which an opening is formed in the wall material side, an outer frame is attached to a box-shaped connecting duct that communicates with a ventilation duct, and an inner frame with a replaceable dust filter attached is attached so that it can be freely inserted and removed from the front side (see Patent Document 2). In this ventilation unit, locking members that are resiliently biased outward by torsion springs are provided on both left and right sides of the inner frame, and holes are drilled on both left and right sides of the outer frame to receive the locking members when the inner frame is attached. When the inner frame is attached to or detached from the outer frame, the protruding ends of the locking members of the inner frame slide on both left and right sides of the outer frame between the outer opening of the outer frame and the holes, from the outer frame opening toward the holes or from the holes toward the outer frame opening, while receiving the biasing force of the torsion spring. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Utility Model Registration No. 2525300 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-21688 Summary of the Invention [Problem to be solved by the invention]

[0006] In the above ventilation unit structure, the protruding end slides against the outer frame halfway through fitting the inner frame to the outer frame, preventing smooth installation of the inner frame. Also, when attaching or detaching the inner frame to or from the outer frame, the protruding end of the locking member applies force to the inner surface of the outer frame, and depending on the material, this can leave band-like marks and damage the decorative surface.

[0007] The present invention has been made to solve the above-mentioned problems, and aims to provide a ventilation unit and ventilation system that has a simple configuration, allows the inner frame to be attached and detached smoothly, and can prevent scratches from occurring on the decorative surface of the outer frame. [Means for solving the problem]

[0008] The ventilation unit according to one aspect of the present invention is a ventilation unit that can be attached to a connecting duct that communicates with a ventilation duct and that has a connecting opening facing an opening provided in an inner wall surface, and includes an outer frame that can be fitted into the connecting duct, an inner frame that is attached to the outer frame so that it can be freely inserted and removed from the front side and to which a replaceable dust filter is attached, and a locking mechanism that locks the inner frame to the outer frame. For example, the connecting duct is box-shaped, and the outer frame and inner frame can be configured to be rectangular tubular in shape to match the internal space size (cross-sectional shape) of the connecting duct.

[0009] In the present invention, the locking mechanism is provided on an outer frame that is fitted into the connecting duct, and includes a locking member on the inside of which a protruding piece with a curved outer surface is resiliently biased so as to be freely protruded and retracted, and a receiving portion provided on the inner frame that receives the protruding piece of the locking member.

[0010] When the inner frame is inserted or removed from the outer frame, the receiving portion of the inner frame reaches the locking member of the outer frame, receiving and locking the locking member. When the inner frame is fitted into the outer frame, the locking member provided on the inside of the outer frame is prevented from protruding from the inner surface of the outer frame by the rear end of the inner frame's connecting duct (where, for example, a dust filter attachment / detachment portion is provided), allowing the inner frame to be smoothly attached all the way to the stopping position. Furthermore, regardless of the material, sliding marks are prevented from being left on the outer frame, and the aesthetic appearance of the inner surface of the outer frame is maintained.

[0011] For example, the receiving portion may be a hole, or may be a recess in the outer surface of the inner frame.

[0012] The outer frame may be provided with a stopper that restricts the inner frame from moving backward when the inner frame is fitted into the outer frame and housed therein, thereby enabling the inner frame to be securely held at a predetermined position in the inward / outward direction relative to the outer frame.

[0013] It is also possible to provide a flange portion at the outer end of the outer frame in the inward / outward direction, and the inward / outward mounting position of the stopper can be set at a position where the inner frame protrudes outward beyond the flange portion of the outer frame.

[0014] A ventilation system according to one aspect of the present invention includes the ventilation unit described above, a ventilation duct, and a connection duct to which the ventilation unit can be attached, which has an opening facing the indoor space and communicates with the ventilation duct. The connection duct is provided with a receiving portion capable of receiving at least a part of the locking member protruding from the outer surface of the outer frame. For example, the receiving portion is formed by a hole.

[0015] To facilitate cleaning of the inside of the connecting duct, it is possible to provide a slope between the bottom and the inner wall facing the opening of the connecting duct. Also, to increase the speed of the air passing through the ventilation duct, it is possible to make the opening tubular part of the connecting duct that connects to the ventilation duct an elliptical cross section. [Effects of the Invention]

[0016] According to the ventilation unit and ventilation system of the present invention, the inner frame can be smoothly attached and detached with a simple configuration, and scratches on the decorative surface of the outer frame can be reduced. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is an explanatory diagram showing a toilet in which a ventilation structure according to one embodiment of the present invention is installed. [Figure 2] 2 is an explanatory diagram showing the arrangement of the ventilation duct, outer frame, inner frame, and toilet bowl of the ventilation structure of FIG. 1. FIG. [Figure 3] 2 is a front view showing the state in which an inner frame is attached to the outer frame of the ventilation structure of FIG. 1, a longitudinal cross-sectional view of that state, a cross-sectional view of the main part, and an explanatory diagram showing the connection between the branch pipe and the connecting duct. [Figure 4] 2 is a perspective view showing a state in which the outer frame and the inner frame of the ventilation structure of FIG. 1 are separated. FIG. [Figure 5] 10A and 10B are explanatory views showing a locking member exposed on the outer surface of an outer frame of the locking mechanism and a cross-sectional view of a main part. [Figure 6] An explanatory diagram showing a lower wall panel with an opening formed therein, an explanatory diagram showing the state in which the outer frame is inserted through the opening in the lower wall panel and the flange portion is attached to the lower wall panel, and an explanatory diagram showing the state in which the inner frame with a dust filter attached is fitted into the outer frame. [Figure 7] FIG. 10 is a perspective view showing a ventilation structure according to a modified example of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0018] The ventilation structure (ventilation system) of this embodiment is a ventilation structure that connects an opening formed in a wall material installed on a wall surface inside a room to a ventilation duct, and ventilates the room by sucking in air.The ventilation structure is installed between the opening in the wall material and the opening on the ventilation duct side that is drawn in and positioned near the opening, and is composed of an outer frame that connects these two openings, an inner frame that is attached to the outer frame so that it can be freely inserted and removed from the front side and has a replaceable dust filter attached to it, and a locking mechanism that locks the inner frame to the outer frame.This locking mechanism is realized by configuring it to include a locking member that is installed on the outer frame and has a protruding piece with a curved outer surface that is resiliently biased so that it can be freely protruded and retracted, and a receiving portion that is installed on the inner frame and receives the protruding piece of the locking member.

[0019] The present invention will be described below with reference to examples shown in the drawings. A ventilation structure (ventilation system) 2 according to one embodiment of the present invention is installed in a room 3, such as a toilet, used by an unspecified number of people, as shown in FIGS. 1 and 2. Upper wall panels (wall materials) 5 are installed in parallel on the wall surfaces of the room 3 at a predetermined height from the floor 4. Lower wall panels (wall materials) 7 are installed between the floor 4 and the upper wall panels 5, providing an internal storage space S for equipment. The lower wall panels 7 are composed of a shorter lower wall panel 7A with a ventilation opening 8 formed at the bottom and a longer lower wall panel 7B with a toilet 9 attached to the front side. These lower wall panels 7A and 7B are arranged alternately to form a lower wall panel section 10. The equipment storage space S (see FIG. 2) formed between the lower wall panel section 10 and the wall surface on which the upper wall panel 5 is installed is provided with a top panel 11 that covers the upper opening.

[0020] As shown in Figure 2, a ventilation duct 12 is drawn into the space S defined between the lower wall panel portion 10 and the wall surface. The intake and exhaust ends of the ventilation duct 12 are connected to the outside air via a ventilation fan (not shown). Branch pipes 13 (13A, 13B, 13C) are connected to the ventilation duct 12 at predetermined intervals depending on the arrangement of the toilet 9. These branch pipes 13 are drawn near the ventilation opening 8, and the other end opening 14 of the branch pipe 13 faces the opening 8 of the lower wall panel 7A at a predetermined distance (see Figure 3 (B)). The lower end opening 14 of this branch pipe 13 is connected to the upper opening tubular portion 15B of the connection duct 15. The opening tubular portion 15B has an elliptical cross section to increase the wind speed. The connection duct 15 is disposed opposite to the opening 8, and a connection opening 15A is formed on the surface facing the opening 8, into which one end of the outer frame 20 described below is fitted.

[0021] In the ventilation structure 2 according to this embodiment, a box-shaped ventilation unit 100 can be detachably attached to a connection duct 15 that fits into an opening 8 formed in a wall surface facing the space of the room 3. An outer frame 20 connects and communicates with the opening 8 in the lower wall panel 7A and the connection opening 15A of the connection duct 15. As shown in FIG. 4 , the outer frame 20 is formed in a rectangular tubular shape so that its outer periphery matches the rectangular opening 8 in the lower wall panel 7A. The outer frame 20 includes an outer frame main body 21 that connects and communicates between the opening 8 in the lower wall panel 7A and the connection opening 15A of the connection duct 15, a flange portion 23 formed on the front edge (the outer edge in the inward / outward direction) of the outer frame main body 21, and a stopper 24 formed to protrude from the inner surface of the outer frame main body 21 at a predetermined distance in the depth direction from the front edge. When the outer frame body 21 is inserted through the opening 8 of the lower wall panel 7A and connected to the connecting duct 15, the flange portion 23 faces and abuts against the opening periphery 8A of the lower wall panel 7A. Mounting holes are drilled in the corners of the flange portion 23. The outer frame 20 is attached to the lower wall panel 7A by fitting the inner opening end 20A facing inward and outward into the connecting opening 15A of the connecting duct 15 through the opening 8 of the lower wall panel 7A, abutting the flange portion 23 against the opening periphery 8A of the lower wall panel 7A, and threading the mounting screws 22 into the mounting holes in the flange portion 23 (see FIG. 3(C)). In this way, the outer frame 20 connects the room 3 to the ventilation duct 12 via the connecting duct 15 and the branch pipe 13.

[0022] The inner frame 30 is attached to the outer frame 20 so as to be freely inserted and removed from the outer opening (front opening) 20B in the inward / outward direction. The inner frame 30 is formed in a square tube shape that roughly matches the inner surface of the outer frame main body 21 so that it can be fitted into the inner surface of the outer frame main body 21. Armor plates 31 are attached horizontally at predetermined intervals to the outer side (front side) of the inner frame 30. Support plates 32 that support the armour plates 31 are provided on both the left and right sides of the armour plates 31. These armour plates 31 and support plates 32 form handles. The armour plates 31 are gripped by the operator's hands and are used to insert and remove the inner frame 30 from the outer frame 20.

[0023] The inner frame 30 has a removable section 34 on its rear side (inner side in the inward / outward direction) for attaching a replaceable dust filter 33. The removable section 34 is formed by bending both inner side edges of the inner frame 30 inward and bending the bottom edge upward, allowing the dust filter 33 to be inserted and removed through the top opening. Once the dust filter 33 is attached to the removable section 34, the worker grasps the armor plate 31 by hand and pushes it into the outer frame 20. When the inner end surface of the removable section 34 abuts against the stopper 24 of the outer frame 20, further displacement of the inner frame 30 is restricted, and the inner frame 30 is attached to the outer frame 20 in this restricted position. At this time, the outer end surface of the inner frame 30 is positioned approximately flush with the flange portion 23. Because no protruding parts are present, safety is ensured even if a user's body comes into contact with the removable section 34. Furthermore, by making the surfaces flush, it is possible to impress users with the aesthetic design. Spare inner frames 30 may be stocked in case of theft or damage.

[0024] The dust filter 33 is constructed from a single plate of stainless steel punched metal with numerous circular holes. This dust filter 33 is available in multiple types with different circular hole diameters, allowing for selection of an appropriate filter by varying the aperture ratio depending on the facility's ventilation plan. Because the dust filter 33 is constructed from a single metal plate, the inner frame 30 is removed from the outer frame 20, the dust filter 33 is pulled out of the inner frame 30, and cleaned on-site to remove moisture. The dust filter 33 is then reinserted into the inner frame 30, and the inner frame 30 with the attached dust filter 33 is then attached to the outer frame 20, completing the cleaning process. If on-site cleaning is not possible, the dust filter 33 can be removed from the inner frame 30 and replaced with a new one. The dirty dust filter 33 can be cleaned elsewhere, or the entire inner frame 30 can be replaced with a new one. The dust filter 33 may also be constructed from a single plate with a lattice pattern or numerous slits. The dust filter 33 may be made of a disposable synthetic resin plate instead of a metal plate. The outer frame 20, inner frame 30, and dust filter 33 are coated with an anti-rust paint in a color that matches the wall panels 5, 7A, and 7B.

[0025] The connecting duct 15 is formed in a box shape, and has an inclined portion 18 between the bottom 17 and the inner wall 16 facing the opening 15A. This allows cleaning water to easily flow outward when the inner frame 30 is removed from the outer frame 20 to clean the inside of the outer frame 20 and the connecting duct 15. Waterproof adhesive tape, such as aluminum tape, is attached to the step between the inner edge of the outer frame 20 and the inner surface of the connecting duct 15. Even when the inner frame 30 is removed from the outer frame 20, the inner surface of the outer frame 20 has a decorative surface formed by plating or painting, so that the appearance is maintained even when the inner surface is exposed.

[0026] A locking mechanism 40 is provided on the inner frame 30 and the outer frame 20. As shown in Figures 5(A) and (B) , the locking mechanism 40 is provided on both left and right frame sections 21A, 21B of the outer frame 20, and is configured to include locking members 43, 43 having a triangular door spring structure that resiliently biases protruding pieces 43A, 43A that are V-shaped in cross section inside these side frames 21A, 21B so that they can protrude and retract, and holes (receiving portions) 45, 45 that are formed on both left and right frame sections 30A, 30B of the inner frame 30 corresponding to the protruding pieces 43A, 43A of the locking members 43, 43, respectively, and that receive these protruding pieces 43A, 43A when the inner frame 30 is fitted into the outer frame 20 and abuts against the stopper 24.

[0027] Each locking member 43, 43 is provided above and below the outside of openings 42, 42 that open into both the left and right side frames 21A, 21B of the outer frame 20, and is configured to include a support plate 35 with an opening formed therein, shaft support portions 41A, 41B formed above and below the opening of this support plate 35, a shaft 41C journaled between these shaft support portions 41A, 41B, a protruding piece 43A made of a bent metal piece with a dog-ear cross section that is housed so as to be able to freely move in and out of the openings 42, 42 inside the left and right side frames 21A, 21B of the outer frame 20 but is prevented from falling out, and a torsion spring (spring) 44 that is inserted onto the shaft 41C and has both ends pressed against the inner surfaces of the protruding piece 43A to resiliently urge the protruding piece 43A toward the inside of the left and right side frames 21A, 21B.

[0028] Furthermore, the holes 45, 45 bored in the left and right frame portions 30A, 30B of the inner frame 30, respectively, are adapted to receive the protruding pieces 43A of the locking member 43 when the inner frame 30 reaches the stopper 24 of the outer frame 20. Therefore, in the locking mechanism 40, when the inner frame 30 is fitted into the outer frame 20 from the attachment / detachment portion 34 side and the outer surfaces of the left and right frame portions 30A, 30B of the inner frame 30 abut against the protruding pieces 43A, 43A, the left and right frame portions 30A, 30B retract the protruding pieces 43A, 43A inward from the openings 42, 42 against the biasing force of the torsion springs 44, 44, and when the inner frame 30 abuts against the stopper 24, the resilient biasing force of the torsion springs 44, 44 causes the protruding pieces 43A, 43A to protrude into the holes 45, 45 of the inner frame 30, thereby locking and holding the inner frame 30 in that position. When the inner frame 30 is pulled outward with a force that overcomes the elastic force of the torsion springs 44, the protruding pieces 43A, 43A disengage from the holes 45, 45, the lock is forcibly released, and the inner frame 30 is pulled out from the outer frame 20. Note that the receiving portion that receives the protruding piece 43A of the locking member 43 is configured as a hole 45 drilled in the inner frame 30, but this is not limited to this and the inner frame 30 may be configured by forming a recess that is recessed inward. Therefore, the protruding pieces 43A, 43A of the locking members 43, 43 slide only between the rear edge of the inner frame 30 and the holes 45, 45 formed in both the left and right frames 30A, 30B, and no sliding marks are left on the outer frame 20.

[0029] The connecting duct 15 is formed with a hole (accommodating portion) 19, which accommodates portions of the locking members 43, 43 provided on the outer frame 20 that protrude outward from both side frames 21A, 21B of the outer frame 20, i.e., the support plate 35, the shaft support portions 41A, 41B, the shaft 41C, and the torsion spring 44. That is, when the inner frame 30 is fitted into the outer frame 20 and the protruding pieces 43A, 43A are inserted into the holes 45, 45 and locked, the hole (accommodating portion) 19 accommodates portions of the locking members 43, 43. The connecting duct 15 is made of a thin metal plate and is deformable. Instead of the hole 19, a recessed portion may be formed on the outside of the connecting duct 15 to accommodate portions of the locking members 43, 43.

[0030] Next, the operation of the ventilation structure 2 according to the embodiment will be described. In the ventilation structure 2 according to the embodiment, first, a connecting duct 15 is installed in the branch pipe 13 of the ventilation duct 12, and an opening 8 is formed in the lower wall panel 7A according to the arrangement of the connecting duct 15. Next, the lower wall panel 7A with the opening 8 formed therein is installed in a room 3 such as a toilet (see FIG. 6A). Then, the outer frame 20 is inserted into the lower wall panel 7A through the opening 8, and the inner opening end 20A of the outer frame 20 facing inward and outward is fitted into the connecting opening 15A of the connecting duct 15, so that the flange portion 23 abuts against the opening periphery 8A of the lower wall panel 7A, and the flange portion 23 is attached to the lower wall panel 7A with the mounting screws 22. In this state, the branch pipe 13 and the room 3 are connected by the outer frame 20 (see FIG. 6B). Next, the dust filter 33 is attached to the detachable portion 34 of the inner frame 30. The inner frame 30 is then fitted into the front opening 20B of the outer frame body 21 by manually grasping the armor plate 31 and pushing it in until it abuts against the stopper 24, attaching it to the outer frame 20 in the restricted position. At this time, the protruding piece 43A of the locking member 43 of the locking mechanism 40 is resiliently held by the torsion spring 44 in the hole 45 of the inner frame 30, so that the inner frame 30 is securely held relative to the outer frame 20. At this time, parts 35, 41A, 41B, 41C, and 44 of the locking member 43 are received in the hole 19 of the connecting duct 15. Thus, air within the chamber 3 is guided through the dust filter 33 of the inner frame 30, the connecting duct 15, the branch pipe 13, and the ventilation duct 12, and then exhausted.

[0031] As described above, with the locking mechanism 40 of the ventilation structure according to this embodiment, even if the inner frame 30 is repeatedly attached and detached, no sliding marks of the locking members 43, 43 are left on the outer frame 20 side. This maintains the aesthetic appearance of the decorative surface of the outer frame 20. Furthermore, since the connecting duct 15 connected to the bottom 21C of the outer frame 20 has an inclined portion 18 between the inner wall 16 and the bottom 17, when the inner frame 30 is removed for cleaning, cleaning water flows more easily to the outside, making the cleaning process more efficient.

[0032] FIG. 7 is a perspective view showing a ventilation structure according to a modification of the above-described embodiment. In the ventilation structure 2 according to the above-described embodiment, the stopper 24 is attached to the outer surface of the inner frame 30, i.e., at a position where the front surface and the flange of the outer frame are flush with each other. By making the outer and inner frames flush with each other, the aesthetic design is emphasized to the user. In contrast, the stopper is attached to the inner and outer sides so that the front surface 130C of the inner frame 130 protrudes outward from the flange 123 of the outer frame 120. Protruding the front surface of the inner frame outward gives a strong design impression to the user, emphasizing consideration for the ventilation environment. Alternatively, the front surface of the inner frame may be recessed inward from the flange of the outer frame.

[0033] In the above embodiment, the dust filter 33 is provided on the rear edge of the inner frame 30. However, this is not a limitation. The dust filter 33 may be provided further outward in the inward / outward direction of the inner frame 30, and the holes 45, 45 of the inner frame 30 may be provided closer to the rear edge to shorten the sliding distance of the locking members 43, 43. In the above embodiment, the locking members are formed from bent metal pieces with a U-shaped cross section. However, this is not a limitation. The locking members may be formed from spherical or roll-shaped members that are resiliently biased and can protrude and retract freely. Furthermore, in the above embodiment, the flange portion 23 of the outer frame 20 is attached to the outside of the lower wall panel (wall material) 7A. However, this is not a limitation. If the front surface of the inner frame is flush with the flange portion of the outer frame or protrudes outward or recedes inward, the flange portion 23 may be attached to the rear (inner) side of the lower wall panel 7A to make the design surface appear smaller. Furthermore, while the inner frame 30 is provided with a detachable portion 34 for the dust filter 33, the present invention is not limited to this, and the dust filter may be attached to a square frame in advance, and the square frame may be detachably fitted to the inner frame 30. Furthermore, in the above embodiment, the ventilation structure is provided indoors, such as in a toilet, but the present invention is not limited to this, and it goes without saying that the structure may be provided in any facility where an unspecified number of people enter and exit. [Explanation of symbols]

[0034] 2 Ventilation structure (ventilation system) 3 rooms 7. Wall materials 8 Openings 12 Ventilation duct 15 Connecting duct 15A connection opening 15B Opening cylinder part 18 Slope 19 holes (receiving section) 20 Outer Frame 30 inner frame 33 Dust filter 40 Locking mechanism 43 Locking member 43A Projecting piece 45 holes (receiving part) 100 ventilation unit

Claims

1. A ventilation unit for a toilet that can be attached to a connection duct that forms a connection opening facing an opening provided in a wall surface of a toilet room and communicates with a ventilation duct, a square cylindrical outer frame that can be fitted into the connection duct; an inner frame in the shape of a square tube to which a dustproof filter is replaceably attached, the inner frame being fitted into and housed in the outer frame through an opening on the front side and then pulled out; a locking mechanism that locks the inner frame to the outer frame, The locking mechanism is provided with a locking member provided on the outer frame, the locking member having a protruding piece with a curved outer surface resiliently biased by a spring so as to be able to protrude and retract freely, and a receiving portion provided on the inner frame for receiving the protruding piece of the locking member. When the inner frame is pushed into the outer frame from the front opening, the inner frame hits the protruding piece and retreats in the opposite direction to the protruding direction of the protruding piece, so that the inner frame is accommodated within the outer frame along both side surfaces of the outer frame, and the inner frame is locked with respect to the outer frame at a position where the discharge piece protrudes from the receiving portion, This ventilation unit for a toilet is characterized in that when the inner frame is pulled toward the front opening of the outer frame with a force that overcomes the biasing force of the spring, the lock is released and the inner frame is pulled out from the outer frame.

2. 2. The ventilation unit for a toilet according to claim 1, wherein the receiving portion is constituted by a hole.

3. A ventilation unit for a toilet that can be attached to a connection duct that forms a connection opening facing an opening provided in a wall surface of a toilet room and communicates with a ventilation duct, an outer frame that can be fitted to the connecting duct; an inner frame that is attached to the outer frame so as to be freely inserted and removed, and to which a dustproof filter is attached so as to be replaceable, the inner frame being inserted and housed through an opening on the front side of the outer frame and then pulled out; a locking mechanism that locks the inner frame to the outer frame, The locking mechanism includes a locking member provided on the outer frame and having a protruding piece formed on the inner surface of the outer frame elastically biased so as to be protruding and retracting, and a receiving portion provided on the inner frame for receiving the protruding piece of the locking member. When the inner frame hits the protruding piece, the protruding piece retracts in the opposite direction to the protruding direction, The outer frame is provided with a stopper for restricting the retraction of the inner frame when the inner frame is fitted into the outer frame and housed therein; This ventilation unit for a toilet is characterized in that the stopper is attached at a position where the inner frame protrudes from a flange portion formed on the edge of the front opening of the outer frame when the inner frame is housed in the outer frame.

4. A ventilation unit; Ventilation ducts and The ventilation unit can be attached to an opening in the wall of the toilet room. a connecting duct that forms a connecting opening and communicates with the ventilation duct; The ventilation unit comprises an outer frame that can be fitted into the connecting duct, an inner frame that is attached to the outer frame so as to be freely inserted and removed from the front side and to which a dustproof filter is attached so as to be replaceable, and a locking mechanism that locks the inner frame to the outer frame, the locking mechanism comprising a locking member that is provided on the outer frame and has a protruding piece formed on its inner surface into a curved surface and is resiliently biased so as to be protruded and retracted, and a receiving portion that is provided on the inner frame and receives the protruding piece of the locking member, A ventilation system for a toilet, characterized in that the connecting duct is provided with a storage portion capable of storing at least a part of a locking member protruding from the outer surface of the outer frame.

5. 5. The toilet ventilation system according to claim 4, wherein the receiving portion is constituted by a hole.

6. 6. The ventilation system for a toilet according to claim 4, wherein the connecting duct has an inclined portion between the bottom and an inner wall facing the opening.

7. 7. The toilet ventilation system according to claim 4, wherein the opening of the connecting duct, which is connected to the ventilation duct, has an elliptical cross section.

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