JP7808286B2 - Ventilation units and systems - Google Patents

Description

The present invention relates to a ventilation unit and ventilation system (hereinafter also referred to as a ventilation structure) for toilets and other facilities used by an unspecified number of people.

In toilets, a ventilation opening is provided in the baseboard between the floor and the wall material that defines the interior of the toilet. This opening is connected to a ventilation duct via a branch pipe, and the other end of the ventilation duct is connected to the outdoors, with the air forced out by a ventilation fan (see, for example, Patent Document 1).

In this type of ventilation structure, a ventilation box is connected to the open end of the branch pipe and placed 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 can become clogged in the mesh, reducing ventilation performance. Therefore, if a clogged mesh is discovered during maintenance and inspection, the ventilation box is removed and replaced. However, to replace the mesh, the toilet must first be closed and the baseboard removed. The ventilation box is then 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 replacement process being time-consuming and preventing the toilet from being used during the work.

Meanwhile, a ventilation unit (ventilation box) is known in which an opening is formed on the wall material side, an outer frame is attached to a box-shaped connecting duct that communicates with the ventilation duct, and an inner frame with a replaceable dust filter is attached so that it can be freely inserted and removed from the front side (see Patent Document 2). In this 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 end of the locking member of the inner frame slides between the outer opening of the outer frame and the hole, from the outer frame opening toward the hole, or from the hole toward the outer frame opening, on both left and right sides of the outer frame while being biased by the torsion spring.

Utility Model Registration No. 2525300 Japanese Patent Application Laid-Open No. 2015-21688

With the above ventilation unit structure, the protruding end slides against the outer frame halfway through fitting the inner frame into the outer frame, preventing smooth installation of the inner frame. Furthermore, when attaching or detaching the inner frame to or from the outer frame, the inner surface of the outer frame is subjected to force from the protruding end of the locking member, and depending on the material, this can leave band-like rubbing marks and damage the decorative surface.

The present invention was made to solve the above problems, and aims to provide a ventilation unit and ventilation system with a simple configuration that allows for smooth attachment and detachment of the inner frame and reduces the occurrence of scratches on the decorative surface of the outer frame.

One aspect of the present invention is a ventilation unit that can be attached to a connecting duct that communicates with the ventilation duct and has a connecting opening facing an opening provided in an inner wall surface. It includes an outer frame that can be fitted into the connecting duct, an inner frame that can be freely inserted and removed from the front side of the outer frame 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 can be box-shaped, and the outer and inner frames can be configured to be rectangular cylindrical to match the size (cross-sectional shape) of the internal space of the connecting duct.

In this invention, the locking mechanism is provided on an outer frame that fits over the connecting duct, and includes a locking member with a curved outer surface that is resiliently biased so that it can freely protrude and retract, and a receiving portion that is provided on the inner frame and receives the locking member's protruding piece.

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 attached to 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.

For example, the receiving portion can be configured as a hole. It can also be configured as a recess on the outer surface of the inner frame.

The outer frame may be provided with a stopper that prevents the inner frame from moving backward when the inner frame is fitted into the outer frame, ensuring that the inner frame is held securely in a predetermined position in the inward/outward direction relative to the outer frame.

It is also possible to provide a flange on the outer end of the outer frame, and the stopper's mounting position in the inward/outward direction can be set so that the inner frame protrudes outward beyond the flange on the outer frame.

One aspect of the present invention is a ventilation system that includes the above-described ventilation unit, a ventilation duct, and a connection duct to which the ventilation unit can be attached, which forms an opening toward the indoor space and communicates with the ventilation duct. The connection duct is provided with a storage portion that can store at least a portion of the locking member that protrudes from the outer surface of the outer frame. For example, the storage portion is configured as a hole.

To facilitate cleaning inside the connecting duct, it is possible to provide a sloped section between the bottom and the inner wall facing the opening. Also, to increase the speed of the air passing through the ventilation duct, it is possible to make the opening tubular section of the connecting duct that connects to the ventilation duct elliptical in cross section.

The ventilation unit and ventilation system according to the present invention have a simple configuration that allows for smooth attachment and detachment of the inner frame, reducing the risk of scratches on the decorative surface of the outer frame.

1 is an explanatory diagram showing a toilet in which a ventilation structure according to one embodiment of the present invention is installed. 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. [0023] FIG. 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 view showing the connection between the branch pipe and the connecting duct. 2 is a perspective view showing the ventilation structure of FIG. 1 in a state where the outer frame and the inner frame are separated. FIG. 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. 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. FIG. 10 is a perspective view showing a ventilation structure according to a modified example of the embodiment.

The ventilation structure (ventilation system) of this embodiment connects an opening formed in a wall material installed on an indoor wall to a ventilation duct, and draws in indoor air for ventilation. The ventilation structure is arranged between the opening in the wall material and the ventilation duct opening located 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 and has a replaceable dust filter attached, and a locking mechanism that locks the inner frame to the outer frame. This locking mechanism is realized by comprising a locking member attached to the outer frame and having 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 attached to the inner frame that receives the protruding piece of the locking member.

The present invention will now be described with reference to the accompanying 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 side by side on the wall surfaces of the room 3 at a predetermined height above the floor 4. Lower wall panels (wall materials) 7 are installed side by side between the floor 4 and the upper wall panels 5, providing an internal equipment storage space S. The lower wall panels 7 are comprised of a narrow lower wall panel 7A with a ventilation opening 8 formed at the bottom and a long 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. A top panel 11 is provided to cover the upper opening of 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.

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 upper opening 14 of this branch pipe 13 is connected to the upper tubular opening portion 15B of the connecting duct 15. The tubular opening portion 15B has an elliptical cross section to increase wind speed. The connection duct 15 is positioned facing 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.

In the ventilation structure 2 according to this embodiment, a box-shaped ventilation unit 100 can be detachably attached to a connecting duct 15 that fits into an opening 8 formed in a wall surface facing the interior space of the room 3. An outer frame 20 connects and communicates the opening 8 in the lower wall panel 7A with the connecting opening 15A of the connecting duct 15. As shown in FIG. 4, the outer frame 20 is formed in a rectangular cylindrical shape with its outer periphery matching the rectangular opening 8 in the lower wall panel 7A. The outer frame 20 includes an outer frame body 21 that connects and communicates between the opening 8 in the lower wall panel 7A and the connecting opening 15A of the connecting duct 15, a flange portion 23 formed on the front edge (the outer edge in the inward/outward direction) of the outer frame body 21, and a stopper 24 formed protruding from the inner surface of the outer frame body 21 a predetermined distance in the depth direction from the front edge. When the outer frame body 21 is inserted through the opening 8 in 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 inserting the inner opening end 20A (facing inward and outward) into the connecting opening 15A of the connecting duct 15 through the opening 8 in 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 Figure 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.

The inner frame 30 is attached to the outer frame 20 so that it can be freely inserted and removed through the outer opening (front opening) 20B in the inward/outward direction. The inner frame 30 is formed in a rectangular cylindrical 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 a specified interval to the outer side (front side) of the inner frame 30. Support plates 32 that support the armor plates 31 are provided on both the left and right sides of the armor plates 31. These armor plates 31 and support plates 32 form a handle. The armor plates 31 are gripped by the operator's hand and used to insert and remove the inner frame 30 from the outer frame 20.

The inner frame 30 has a removable section 34 on its back (inner side) 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 with their hands and pushes it into the outer frame 20. When the inner end face of the removable section 34 abuts 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 face of the inner frame 30 is positioned approximately flush with the flange 23. This elimination of protruding parts ensures safety even if a user's body comes into contact with the removable section 34. Furthermore, having the same surface makes an aesthetic impression on users. Spare inner frames 30 may be stocked in case of theft or damage.

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 inner frame 30 with the attached dust filter 33 is then reinserted into the inner frame 30 on-site, and the cleaning process is completed by attaching the inner frame 30 with the attached dust filter 33 back to the outer frame 20. 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. Additionally, the dust filter 33 may be made of a synthetic resin plate instead of a metal plate, making it disposable. The outer frame 20, inner frame 30, and dust filter 33 are also coated with an anti-rust paint in a color that matches the wall panels 5, 7A, and 7B.

The connecting duct 15 is formed in a box shape, with a sloped portion 18 provided 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 connecting duct 15. Waterproof adhesive tape, such as aluminum tape, is affixed 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 is plated or painted to form a decorative surface, maintaining its aesthetic appearance even when the inner surface is exposed.

The inner frame 30 and outer frame 20 are provided with a locking mechanism 40. As shown in Figures 5A and 5B, the locking mechanism 40 is provided on both the left and right side frames 21A and 21B of the outer frame 20. The locking mechanism 40 is comprised of locking members 43, 43 having a triangular door spring structure with protruding pieces 43A, 43A with a V-shaped cross section resiliently biased inside the side frames 21A and 21B, and holes (receiving portions) 45, 45 formed on both the left and right side frames 30A and 30B of the inner frame 30 corresponding to the protruding pieces 43A, 43A of the locking members 43, 43, respectively, which receive the protruding pieces 43A, 43A when the inner frame 30 is fitted into the outer frame 20 and abuts against the stopper 24.

Each locking member 43, 43 is located above and below the outside of openings 42, 42 that open into both the left and right frame members 21A, 21B of the outer frame 20, respectively. It is composed of a support plate 35 with an opening formed therein; shaft support portions 41A, 41B formed above and below the opening of the support plate 35, respectively; a shaft 41C journaled between these shaft support portions 41A, 41B; a protruding piece 43A made of a bent metal piece with a dogleg cross section that is housed inside the left and right frame members 21A, 21B of the outer frame 20 through the openings 42, 42 and is prevented from falling out; and a torsion spring 44 that is inserted onto the shaft 41C and has both ends pressing against the inner surface of the protruding piece 43A, resiliently urging the protruding piece 43A toward the inside of the left and right frame members 21A, 21B.

In addition, the holes 45, 45 drilled in the left and right frame portions 30A, 30B of the inner frame 30 are designed to receive the protruding pieces 43A of the locking member 43 as described above when the inner frame 30 reaches the stopper 24 of the outer frame 20. Therefore, when the inner frame 30 is fitted into the outer frame 20 from the detachable 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. 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, 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 disengage from the holes 45, the lock is forcibly released, and the inner frame 30 can be pulled out from the outer frame 20. While the receiving portion for receiving the protruding piece 43A of the locking member 43 is formed by a hole 45 drilled in the inner frame 30, this is not limited to this and the inner frame 30 may also be formed by forming a recess that is recessed inward. As a result, the protruding pieces 43A of the locking members 43 slide only between the rear edge of the inner frame 30 and the holes 45 formed in the left and right frame sections 30A, 30B, leaving no sliding marks on the outer frame 20.

The connection duct 15 has a hole (accommodation portion) 19 formed therein, 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, shaft support portions 41A, 41B, shaft 41C, and torsion spring 44. In other words, 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 to lock, portions of the locking members 43, 43 are accommodated. The connection duct 15 is made of a thin metal plate and is deformable. Instead of this hole 19, a recessed portion may be formed on the outside of the connection duct 15 to accommodate portions of the locking members 43, 43.

Next, the operation of the ventilation structure 2 according to the above embodiment will be described. In the ventilation structure 2 according to the above embodiment, first, a connecting duct 15 is installed in the branch pipe 13 of the ventilation duct 12, and an opening 8 is provided in the lower wall panel 7A according to the arrangement of this 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). The outer frame 20 is then inserted into the lower wall panel 7A through the opening 8, and the inner opening end 20A of the outer frame 20 is fitted into the connecting opening 15A of the connecting duct 15, bringing the flange portion 23 into contact with the opening periphery 8A of the lower wall panel 7A. The flange portion 23 is then 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 removable portion 34 of the inner frame 30. The inner frame 30 is then manually grasped by the armor plate 31 and inserted into the front opening 20B of the outer frame body 21, pushing it in until it abuts against the stopper 24 and is attached 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 in place by the torsion spring 44, protruding into the hole 45 of the inner frame 30, so that the inner frame 30 is securely held against the outer frame 20. At this time, portions 35, 41A, 41B, 41C, and 44 of the locking member 43 are accommodated in the hole 19 of the connecting duct 15. Air within the chamber 3 is then guided through the dust filter 33 of the inner frame 30, the connecting duct 15, the branch pipe 13, and the ventilation duct 12, where it is exhausted.

As such, 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 from the locking members 43, 43 are left on the outer frame 20. This allows the decorative surface of the outer frame 20 to maintain its aesthetic appearance. Furthermore, 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. This makes it easier for cleaning water to flow outward when the inner frame 30 is removed and cleaned, making the cleaning process more efficient.

Figure 7 is a perspective view showing a ventilation structure according to a modification of the above embodiment. In the ventilation structure 2 according to the above embodiment, the stopper 24 is attached in the inward/outward direction to the outer surface of the inner frame 30, i.e., at a position where the front surface and the flange portion of the outer frame are flush with each other. By making the outer and inner frames flush with each other, a design aesthetic is impressed on the user. In contrast, the stopper is attached in the inward/outward direction to a position where the front surface 130C of the inner frame 130 protrudes outward from the flange portion 123 of the outer frame 120. Having the front surface of the inner frame protrude outward gives a strong design impression to the user, emphasizing consideration for the ventilation environment. The front surface of the inner frame may also be set back inward from the flange portion of the outer frame.

While the above embodiment features a dust filter 33 on the rear edge of the inner frame 30, this is not a limitation. The filter may be located further outward in the inward/outward direction of the inner frame 30, with the holes 45, 45 of the inner frame 30 positioned closer to the rear edge, thereby shortening the sliding distance of the locking members 43, 43. While the above embodiment features a bent metal piece with a U-shaped cross section, this is not a limitation. The locking member may be a spherical or roll-shaped member that is resiliently biased and can be retracted. Furthermore, while the above embodiment features a flange 23 of the outer frame 20 attached to the outside of the lower wall panel (wall material) 7A, this is not a limitation. If the front surface of the inner frame is flush with the flange of the outer frame, or if the flange 23 is projected outward or recessed inward, the flange 23 may be attached to the rear (inner) side of the lower wall panel 7A to reduce the appearance of the design surface. Furthermore, while the inner frame 30 is provided with a detachable portion 34 for the dust filter 33, this is not limited to this; the dust filter may be pre-attached to a square frame, and this square frame may be detachably fitted to the inner frame 30. Furthermore, in the above embodiment, the ventilation structure is installed indoors, such as in a toilet, but this is not limited to this, and it goes without saying that it may be installed in any facility where an unspecified number of people enter and exit.

2. Ventilation structure (ventilation system)
3 Chamber 7 Wall material 8 Opening 12 Ventilation duct 15 Connection duct 15A Connection opening 15B Opening tubular portion 18 Inclined portion 19 Hole (accommodation portion)
20 outer frame 30 inner frame 33 dustproof filter 40 locking mechanism 43 locking member 43A protruding piece 45 hole (receiving portion)
100 ventilation unit

Claims (7)

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 . A toilet ventilation unit as described in claim 1, characterized in that the receiving portion is composed of a hole. 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, when the inner frame is housed in the outer frame, the inner frame protrudes from a flange portion formed on the edge of the front opening of the outer frame. A ventilation unit;
Ventilation ducts and
a connecting duct that can be fitted with a ventilation unit, that forms a connecting opening facing an opening provided in a wall surface of the indoor space of the toilet, and that 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. The toilet ventilation system of claim 4, characterized in that the storage portion is composed of a hole. A toilet ventilation system as described in claim 4 or 5, characterized in that the connecting duct has a sloped portion between the inner wall facing the opening and the bottom. 7. The ventilation system for a toilet according to claim 4, wherein the cylindrical opening of the connection duct, which is connected to the ventilation duct, has an elliptical cross section.