JP2021143811A - Duct and ventilator - Google Patents

Abstract

To provide a duct and a ventilator in which raindrops are hard to pass through a downstream side opening.SOLUTION: A weather cover 10, which is a duct, comprises a plurality of upstream blades 13 and downstream blades 15. The plurality of upstream blades 13 is arranged side by side in a direction from an inside wall 11E to an outside wall 11F in the vicinity of a downstream opening 11A. The upstream blade 13 is inclined with respect to a vertical direction in such a direction that its lower end is located on the outside wall 11F side with respect to its upper end. The downstream blade 15 is inclined in the vertical direction so that its upper end is located on a downstream side opening 11B side with respect to its lower end, and is inclined in a direction being opposite to the upstream blade 13.SELECTED DRAWING: Figure 4

Description

The present invention relates to a duct used as a weather cover or the like of a ventilation device, and a ventilation device provided with the duct.

Patent Document 1 discloses a duct including a duct main body having a square cross section and opening at both ends, and a plurality of blades provided inside the duct main body. In this duct, raindrops such as mist are applied to the inner surface of the outer wall constituting the curved flow path of the duct body by the above-mentioned plurality of blades and aggregated as water droplets, and the water droplets are discharged to the outside of the duct by its own weight. can do. As a result, it is possible to prevent raindrops from entering the room or the like through the opening on the downstream side of the duct body.

Japanese Unexamined Patent Publication No. 2012-12650

Even in the duct of Patent Document 1, raindrops may pass through the opening on the downstream side and invade indoors or the like, and there is room for improvement in the duct.

An object of the present invention is to provide a duct and a ventilation device in which raindrops are difficult to pass through a downstream opening.

The duct according to the present invention is a duct body having a square cross section and openings at both ends constituting a curved flow path, one end of which is a downstream opening to be sucked by an intake device, and the other end of which is an upstream opening. The main body, a plurality of upstream blades provided in the vicinity of the upstream opening inside the duct body, and downstream blades provided on the downstream side of the plurality of upstream blades inside the duct body. The duct body comprises an inner wall surface, an outer wall surface facing the inner wall surface, and a pair of side walls facing each other and connected to the inner wall surface and the outer wall surface, which form the curved flow path. Each of the plurality of upstream blades extends from one of the pair of side walls to the other, and the downstream end is inclined so as to be located closer to the outer wall than the upstream end. The blades are arranged side by side in the direction from the inner side wall toward the outer wall, and the downstream blade is located at a position away from the inner side wall and the outer wall and at the center of the flow direction of the curved flow path. Arranged, it extends from one of the pair of side walls to the other and is tilted in the direction opposite to the upstream blade.

The upstream blade is plate-shaped, and the downstream blade is located on the downstream side of the virtual surface whose upstream end is an extension of the surface of the downstream end of each of the plurality of upstream blades to the downstream side. It may be arranged in.

The upstream blade and the downstream blade are plate-shaped, and a virtual surface in which the surface of the downstream blade is extended to the upstream side is a virtual surface in which the surface of the downstream end of the upstream blade is extended to the downstream side. It may be arranged in a direction substantially orthogonal to.

A gutter for receiving water adhering to the downstream blade may be provided at the upstream end of the downstream blade.

The ventilation device according to the present invention includes a weather cover made of the duct, a ventilation fan, and a mounting frame to which the weather cover and the ventilation fan are attached.

According to the duct and the ventilation device according to the present invention, the raindrops are separated from the air flow and applied to the outer wall by the plurality of upstream blades and the downstream blades inclined in the directions opposite to the upstream blades. It can be facilitated and it becomes difficult for raindrops to pass through the downstream opening.

It is sectional drawing of the ventilation apparatus which concerns on embodiment. It is a perspective view of the weather cover of FIG. It is an enlarged perspective view of the downstream side blade of FIG. It is sectional drawing of the weather cover of FIG. 1, and is the sectional view which shows the movement of air and raindrops in a weather cover.

Hereinafter, the duct and the ventilation device according to the embodiment will be described with reference to the drawings. The duct according to the present embodiment is configured as the weather cover 10 of the ventilation device 1 shown in FIG. The ventilation device 1 is attached to the outer wall 90. In the following description, the vertical direction is the vertical direction in which the outer wall 90 extends. Further, the outdoor side of the outer wall 90 is the front, and the indoor side of the outer wall 90 is the rear. Further, the width direction of the outer wall 90 is set to the left-right direction. In addition, in FIGS. 1 and 3, the thickness of each member is exaggerated.

(Structure of ventilation device 1)
As shown in FIG. 1, the ventilation device 1 includes a weather cover 10, a ventilation fan 20, and a cylindrical mounting frame 30 to which the weather cover 10 and the ventilation fan 20 are attached. The ventilation device 1 is attached to the outer wall 90.

The ventilation fan 20 is arranged indoors, and takes in the outdoor air and draws it indoors. The weather cover 10 is arranged outdoors to prevent rainwater from entering the room through the mounting frame 30 and the ventilation fan 20. The mounting frame 30 is attached to the outer wall 90 by a mounting member such as L-shaped steel (not shown) while passing through the opening 91 of the outer wall 90.

The weather cover 10 and the mounting frame 30 form a flow path for outside air, which is the outdoor air taken in by the ventilation fan 20. Therefore, the weather cover 10 is arranged on the upstream side of the air flow path, and the ventilation fan 20 is arranged on the downstream side of the air flow path.

(Structure of weather cover 10)
As shown in FIGS. 1 and 2, the weather cover 10 includes a cover body 11 which is a tubular body having openings at both ends and a cover body 11 which constitutes a curved flow path S which is a flow path of outdoor air taken in by the ventilation fan 20. A plurality of upstream blades 13 and downstream blades 15 arranged inside the above are provided. The curved flow path S includes a linear upstream portion S1 extending in the vertical direction on the upstream side of the flow direction SS, and a linear downstream portion S2 extending in the front-rear direction on the downstream side. The curved flow path S also has a central portion S3 bent 90 degrees in an arc shape, which is arranged between the upstream portion S1 and the downstream portion S2 as the central portion of the flow direction SS. The flow direction SS is a direction along the central axis of the curved flow path S.

The cover main body 11 is a tubular body having a square cross section and openings at both ends, and the central portion thereof is bent so that the inside thereof becomes a curved flow path S. The opening at one end of the cover body 11 faces downward, and is an upstream opening 11A into which outdoor air flows. The opening at the other end of the cover body 11 faces rearward and is a downstream opening 11B that is sucked by the ventilation fan 20. During the operation of the ventilation device 1, outdoor air flows from below through the upstream opening 11A into the upstream portion S1 of the curved flow path S, passes through the central portion S3 and the downstream portion S2, and is attached to the mounting frame from the downstream opening 11B. It flows out to 30.

The cover body 11 includes four walls constituting the curved flow path S. These four walls include an inner side wall 11E, an outer wall 11F, a left side wall 11G, and a right side wall 11H. The inner side wall 11E is arranged inside the curved flow path S. The outer side wall 11F is arranged outside the curved flow path S and faces the inner side wall 11E. The outer side wall 11F includes a central wall 11FA that defines the outer edge of the central portion S3 of the curved flow path S. The central wall 11FA has a shape in which the cylinder is halved in the circumferential direction, and has a cross section of an arc having a central angle of 90 degrees. The left side wall 11G and the right side wall 11H are a pair of side walls facing each other in the left-right direction. The left side wall 11G is arranged on the left side of the curved flow path S, and is connected to the left side of the inner side wall 11E and the left side of the outer wall 11F. The right side wall 11H is arranged on the right side of the curved flow path S, and is connected to the right side of the inner side wall 11E and the right side of the outer wall 11F.

The plurality of upstream blades 13 have a plate shape and are arranged in the vicinity of the upstream opening 11A. More specifically, the plurality of upstream blades 13 are arranged in the upstream portion S1 of the curved flow path S. The plurality of upstream blades 13 are arranged side by side in a direction from the inner side wall 11E toward the outer wall 11F, more specifically, in an oblique direction downward toward the front. The left end and the right end of the upstream blade 13 are fixed to the left side wall 11G and the right side wall 11H by welding or the like, respectively. Therefore, the upstream blade 13 extends from one of the pair of side walls 11G and 11H to the other. The upstream blade 13 extends along the left-right direction, which is the opposite direction between the left side wall 11G and the right side wall 11H.

The upstream blade 13 is tilted in the vertical direction, and the downstream end is located on the outer wall 11F side, that is, outside the curved flow path S, than the upstream end. The upstream blade 13 is bent so that the plate-shaped first portion 13A on the downstream side is tilted at a larger angle with respect to the vertical direction than the plate-shaped second portion 13B on the upstream side. Each of the plurality of upstream blades 13 has the same shape and is tilted at the same angle.

The downstream blade 15 is provided on the downstream side of the plurality of upstream blades 13. The downstream blade 15 is arranged at a position away from the inner side wall 11E and the outer wall 11F and at the central portion S3 of the curved flow path S. The left end and the right end of the downstream blade 15 are fixed to the left side wall 11G and the right side wall 11H by welding or the like, respectively. Therefore, the downstream blade 15 extends from one of the pair of side walls 11G and 11H to the other. The downstream blade 15 extends along the left-right direction, which is the opposite direction between the left side wall 11G and the right side wall 11H.

The downstream blade 15 has a plate shape and is inclined in the direction opposite to the upstream blade 13. Specifically, the downstream blade 15 is located along the tangential direction of the curved flow direction of the central portion S3 of the curved flow path S, in other words, the upper end of the downstream blade 15 is located closer to the downstream opening 11B than the lower end. It is tilted with respect to the vertical direction. Further, in the downstream blade 15, the virtual surface (see the dotted straight line Z1 in FIG. 1) in which the surface of the downstream blade 15 is extended to the upstream side is the surface (upstream side) of the first portion 13A on the downstream side of the upstream blade 13. It is arranged in a direction substantially orthogonal to the virtual surface (see the dotted straight line Z2 in FIG. 1) extending downstream (the surface facing the above). Further, the downstream blade 15 has a virtual surface whose upstream end extends the surface (surface facing the upstream side) of the first portion 13A on the downstream side of each of the plurality of upstream blades 13 to the downstream side (FIG. 1). It is arranged so as to be located on the downstream side of the dotted straight line Z2). That is, the virtual surface passes through the downstream side of the upstream end of the downstream blade 15. Further, the downstream blade 15 is arranged substantially in the center between the central wall 11FA of the outer wall 11F and the central wall 11EA of the inner side wall 11E that partition the central portion S3 of the curved flow path S.

The upstream end of the downstream blade 15 is bent in a substantially U shape. As a result, a gutter 15A extending along the left-right direction and projecting to the outside of the curved flow path S is formed at the upstream end of the downstream blade 15. As shown in FIG. 3, the gutter 15A is provided with one end in the left-right direction having a gap D with the left side wall 11G. Similarly, the other end of the gutter 15A is also provided with a gap from the right side wall 11H.

(Operation of ventilation device 1)
Returning to FIG. 1, the ventilation fan 20 sucks the outdoor air through the upstream opening 11A of the weather cover 10. As a result, air flows into the weather cover 10. The air that has flowed into the weather cover 10 flows out from the downstream opening 11B, is sucked into the ventilation fan 20 through the mounting frame 30, and is supplied indoors.

(Flow of air and raindrops in the weather cover 10 when the ventilation device 1 operates)
The state of the inside of the weather cover 10 when the ventilation fan 20 operates in rainy weather and the outdoor air is drawn indoors will be described with reference to FIG. In rainy weather, raindrops enter the weather cover 10 together with air. In FIG. 4, the alternate long and short dash arrow indicates the movement path of air, and the dotted arrow indicates the movement path of raindrops U1 and U2. In the following description, the outside refers to the outside of the curved flow path S, that is, the outer wall 11F side, and the inside refers to the inside of the curved flow path S, that is, the inner side wall 11E side.

When the ventilation fan 20 operates, the inside of the weather cover 10 is taken into the indoor side through the downstream opening 11B, and as shown by arrows N1 to N4 in FIG. 4, air flows into the upstream opening 11A from below and at the same time. Raindrops U1 and U2 also infiltrate on the air.

Air and raindrops U1 that have entered the cover body 11 from the outer region of the upstream opening 11A pass between the upstream blades 13 that are tilted in the vertical direction, as shown by arrows N5 and N6, and the upstream blades. Guided to the outside by 13, it hits the outer wall 11F. The air that hits the outer side wall 11F then moves in the weather cover 10 along the outer wall 11F and flows into the mounting frame 30. On the other hand, the raindrops U1 that hit the outer wall 11F adhere to the outer wall 11F, move downward along the outer wall 11F, and are finally discharged below the weather cover 10, that is, to the outside. Depending on the size of the raindrops U1, a plurality of raindrops U1 may gather and grow into water droplets, and then move downward along the outer wall 11F.

The air that has entered the cover body 11 from the inner region of the upstream opening 11A is guided by the upstream blade 13 and moves outward as shown by the arrow N7. Here, the upstream end of the downstream blade 15 is located on the downstream side of the virtual surface (see the dotted straight line Z2 in FIG. 1) in which the surface of the first portion 13A on the downstream side of the upstream blade 13 is extended to the downstream side. Therefore, the air that goes outward through the upstream blade 13 flows to the outside of the upstream end through the upstream side of the upstream end of the downstream blade 15. This outward air does not reach the outer wall 11F, but moves to a region outside the downstream blade 15 as shown by arrow N8, and moves to the region outside the downstream blade 15 and the central wall 11FA of the downstream blade 15 and the outer wall 11F. Pass between and. The air that has passed through the upstream blade 13 does not go toward this region G1 due to the vortex described later that is generated in the region G1 that is inside and downstream of the downstream blade 15. The air passing between the downstream blade 15 and the central wall 11FA of the outer wall 11F does not follow the downstream blade 15 due to the boundary layer peeling that occurs in the vicinity region G2 of the surface facing the outside of the downstream blade 15. As shown by the arrow N9, it makes a large turn around the outside of the downstream side blade 15 and heads toward the downstream side opening 11B.

Here, since the air guided by the plurality of upstream blades 13 is not guided toward the region G1, the region G1 has a lower atmospheric pressure than the surrounding region. Therefore, most of the air that makes a large turn around the outside of the downstream blade 15 and moves in the direction of the downstream opening 11B flows to the downstream opening 11B as shown by arrow N10, but a part of the air flows as shown by arrow N11. Then, it flows into the region G1 and an air vortex is generated in the region G1. Since this vortex turns counterclockwise toward the paper surface of FIG. 4, it prevents the air guided by the upstream blade 13 from heading toward the region G1. Therefore, in the weather cover 10, most of the air flowing into the upstream opening 11A passes between the downstream blade 15 and the central wall 11FA of the outer wall 11F and goes toward the downstream opening 11B.

On the other hand, the raindrops U2 that have entered the cover body 11 from the inner region of the upstream opening 11A are guided by the upstream blade 13 together with the air indicated by the arrow N7 and move outward as shown by the arrow N12. .. As shown by the arrow N13, the raindrops U2 guided by the plurality of upstream blades 13 move on the air halfway. After that, the raindrops U2 are touched to the outside of the air by the centrifugal force acting on the raindrops U2 when the air makes a large turn around the outside of the downstream blade 15, and the raindrops U2 are touched to the outside of the air as shown by the arrow N14. It moves to the central wall 11FA and adheres. The raindrops U2 adhering to the central wall 11FA move downward along the outer wall 11F, and are finally discharged to the outside of the weather cover 10. Depending on the size of the raindrops U2, a plurality of raindrops U2 may gather and grow into water droplets, and then move downward along the outer wall 11F.

Further, in this embodiment, raindrops may adhere to the outer surface of the downstream blade 15, but since the gutter 15A is provided at the upstream end of the downstream blade 15, as shown in FIG. 3, the downstream side The gutter 15A receives the raindrops Y or the water droplets in which the raindrops Y adhere to the blade 15 and fall along the downstream blade 15. Further, a gap D is provided between one end of the gutter 15A and the left side wall 11G, and a gap is also provided between the other end of the gutter 15A and the right side wall 11H. It falls along the left side wall 11G or the right side wall 11H from the above, and is discharged to the outside of the weather cover 10.

(Effects, etc.)
According to the weather cover 10 of the present embodiment, since the plurality of upstream blades 13 and downstream blades 15 that are inclined in opposite directions are provided, the boundary layer peeling can occur in the vicinity of the downstream blades 15. The air that has flowed into the weather cover 10 is made to make a large turn between the downstream blade 15 and the outer wall 11F, and the raindrops that have entered with the air are separated from the air flow and hit the outer wall 11F. Can be done. Therefore, according to the weather cover 10, raindrops can hardly enter the room through the downstream opening 11B. In particular, in the weather cover 10, most of the air flowing into the upstream opening 11A is passed between the downstream blade 15 and the central wall 11FA of the outer wall 11F due to the vortex of the region G1, so that the air flows into the weather cover 10. Raindrops also do not pass through region G1 so that many raindrops can hit the outer wall 11F.

Even with the weather cover of the comparative example having a plurality of upstream blades 13 but not having a downstream blade 15, raindrops having a large diameter of 0.7 mm or more can be applied to the outer wall 11F to some extent, but 0. Most of the raindrops having a diameter less than 7 mm get on the air and pass through the downstream opening 11B. In the weather cover 10 provided with the downstream blade 15 as in this embodiment, more raindrops having a small diameter can be applied to the outer wall 11F due to the large turning, and the raindrops pass through the more downstream opening 11B. It's getting harder. Further, in the weather cover 10, more raindrops having a large diameter can be applied to the outer wall 11F.

Further, the downstream blade 15 has a virtual surface whose upstream end extends the surface of the downstream first portion 13A (which may be the downstream end) of each of the plurality of upstream blades 13 to the downstream side. It is arranged so as to be located on the downstream side of the dotted straight line Z2 in FIG. Thereby, the air guided by the plurality of upstream blades 13 can be effectively guided between the upstream blades 13 and the outer wall 11F. Further, in the downstream blade 15, a virtual surface (see the dotted straight line Z1 in FIG. 1) in which the surface of the downstream blade 15 is extended to the upstream side is a first portion 13A on the downstream side of the upstream blade 13 (particularly on the downstream side). The surface of the end portion) is arranged in a direction substantially orthogonal to the virtual surface (see the dotted straight line Z2 in FIG. 1) extending to the downstream side. The degree of orthogonality is preferably 80 to 100 degrees. As a result, the air guided by the upstream blade 13 passes near the lower end of the downstream blade 15 at an angle close to the perpendicular direction of the surface of the downstream blade 15, so that the region of the boundary layer peeling is increased. , The above air can be made larger, and raindrops are more likely to separate. Further, this makes it possible to effectively guide the air guided by the plurality of upstream blades 13 between the upstream blades 13 and the outer wall 11F. Further, the downstream blade 15 is arranged substantially in the center between the central wall 11FA of the outer wall 11F and the central wall 11EA of the inner side wall 11E that partition the central portion S3 of the curved flow path S. As a result, the smoothness of the air flow in the weather cover 10 can be ensured to some extent.

Further, in this embodiment, since the gutter 15A is provided, it is possible to prevent raindrops and the like from directly falling downward from the downstream blade 15. If raindrops fall directly from the downstream blade 15, the raindrops may be blown by the air flowing into the weather cover 10, but this can be prevented by the gutter 15A. Further, the gap between the left and right ends of the gutter 15A and the left side wall 11G and the right side wall 11H allows the water stored in the gutter 15A to be dropped along the left side wall 11G or the right side wall 11H. The water can be made less likely to be agitated by air.

(Modification example)
The structure of the above embodiment may be applied to a duct other than the weather cover 10 as a member constituting a curved flow path in a long air passage. In this case, the cover body becomes a duct body. The ventilation fan may be another air intake device. Examples of the intake device include a sirocco fan, a pump, and the like, in addition to a ventilation fan. The upstream blade 13 and the downstream blade 15 may be curved instead of flat. The weather cover 10 and the ventilation fan 20 may be attached to the attachment frame 30 via other members.

1 Ventilation device, 10 weather cover, 11 cover body, 11A upstream side opening, 11B downstream side opening, 11E inner side wall, 11F outer side wall, 11EA, 11FA central wall, 11G left side wall, 11H right side wall, 13 upstream side blade, 13A 1st part on the downstream side, 13B 2nd part on the upstream side, 15 downstream side blade, 15A gutter, 20 ventilation fan, 30 mounting frame, D gap, G1 area, G2 neighborhood area, S curved flow path, S1 upstream part, S2 Central part, S3 downstream part, SS flow direction, U1, U2, Y rain gutters.

Claims (5)

A duct body having a square cross section and both ends opening to form a curved flow path, one end of which is a downstream opening to be sucked by an intake device, and the other end of which is an upstream opening.
A plurality of upstream blades provided in the vicinity of the upstream opening inside the duct body,
A downstream blade provided on the downstream side of the plurality of upstream blades inside the duct body is provided.
The duct body includes an inner wall surface, an outer wall surface facing the inner wall surface, and a pair of side walls facing each other and connected to the inner wall surface and the outer wall surface, which form the curved flow path.
Each of the plurality of upstream blades extends from one of the pair of side walls to the other, and the downstream end is inclined so as to be located closer to the outer wall than the upstream end.
The plurality of upstream blades are arranged side by side in a direction from the inner side wall toward the outer wall.
The downstream blade is arranged at a position away from the inner side wall and the outer wall and at the center of the curved flow path in the flow direction, extends from one of the pair of side walls to the other, and with the upstream blade. Leaning in the opposite direction,
duct. The duct according to claim 1.
The upstream blade is plate-shaped
The downstream blade is arranged so that the upstream end is located on the downstream side of the virtual surface extending the surface of the downstream end of each of the plurality of upstream blades to the downstream side.
duct. The duct according to claim 1 or 2.
The upstream blade and the downstream blade are plate-shaped.
The virtual surface extending the surface of the downstream blade to the upstream side is arranged in a direction substantially orthogonal to the virtual surface extending the surface of the downstream end of the upstream blade to the downstream side.
duct. The duct according to any one of claims 1 to 3.
At the upstream end of the downstream blade, a gutter for receiving water adhering to the downstream blade is provided.
duct. The weather cover made of the duct according to any one of claims 1 to 4 and the weather cover.
Ventilation fan and
A mounting frame to which the weather cover and the ventilation fan are mounted,
Ventilation system equipped with.

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