WO2018143326A1

WO2018143326A1 - Ventilation port hood

Info

Publication number: WO2018143326A1
Application number: PCT/JP2018/003370
Authority: WO
Inventors: 健吾中原; 訓央清本; 耕次飯尾
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2017-02-06
Filing date: 2018-02-01
Publication date: 2018-08-09

Abstract

A ventilation port hood (1) comprises: a cover (2) where an air current flows in from a side surface part (7) and flows out from a bottom surface part; a cylindrical tube (5) penetrating from the inner side of the cover (2) through the bottom surface part; a space dividing plate that respectively forms a first turning chamber and a second turning chamber in the outer peripheral side of the cylindrical tube (5) and the inner peripheral side of the cover (2); and a columnar member provided so as to face the end surface of the cylindrical tube (5) in the first turning chamber. The cover (2) has a top surface (6) facing the bottom surface part, is provided with a first air supply port (8) in the side surface part (7) at the bottom surface part side thereof, and is provided with a second air supply port in the side surface part (7) at the top surface (6) side thereof. The space dividing plate has a through hole by which the first turning chamber and the second turning chamber communicate, and when the second air supply port is the base point around the center axis, the through hole is positioned such that a distance in the flow direction of the air current going around the first turning chamber is longer than a distance in the reverse flow direction.

Description

Ventilation hood

The present invention relates to a vent hood that is attached to an air intake port of a building outdoor wall that arranges a blower on the downstream side of an air flow and takes outdoor air into the room in order to ventilate the room.

Conventionally, as this type of vent opening hood, for example, the one of Patent Document 1 is known.

The ventilation hood is installed for the purpose of preventing the inflow of rain and wind from the ventilation opening, which is the air intake on the outdoor wall of the building. The vent hood has a cover to prevent rain and wind, an inlet for taking in air, a cylindrical outlet that protrudes to the back of the vent hood to connect to the ventilation duct, small animals and large flying objects It consists of a gallery to prevent inflow.

Also, there is a cyclone separation device as a device for separating small animals and large scattered matter mixed in the air. For example, the thing of patent document 2 is known.

FIG. 17 is a cross-sectional view showing a conventional cyclone separator. As shown in FIG. 17, the cyclone separation device includes an inflow port 101, a swirl chamber 102, an inner tube 103, an inner tube tip 104, and a deposition unit 105. The air containing the foreign matter flows into the apparatus from the inlet 101 and flows in the swirl chamber 102 as a swirling airflow. At this time, the foreign matter is separated to the outer peripheral side of the swirl chamber 102 by centrifugal force. The separated foreign matter accumulates in the accumulation portion 105, and the air flows from the inner cylindrical tube tip 104 into the inner cylindrical tube 103 and flows out of the apparatus.

Also, if a net or the like is used at the inlet, clogging may occur due to foreign matter, and the ventilation air flow may decrease unless maintenance is performed. For this reason, there is a vent hood that uses the cyclone technology that does not cause clogging as in Patent Document 3. This is because the outside air that has flowed in from the inflow port is turned into a swirling airflow by fixed blades provided at the inflow port, and a through-hole that penetrates the separation chamber is provided on the wall surface of the swirl chamber. It is moved and deposited in the separation chamber. As a result, the air from which the foreign matter has been removed flows out from the outlet and is supplied to the room.

JP 2011-242081 A Japanese Patent Laid-Open No. 2000-128591 JP 2008-36579 A

In such a conventional vent hood, there are wide gaps in the louver, and small insects such as moths, mosquitoes and flies flow in. Therefore, a net was installed as a filtration device in the vent hood, and these small insects were collected by the filtration method to prevent inflow into the room.

However, these small insects accumulate on the net, causing clogging, making it impossible to take in air and securing a predetermined ventilation rate, and there is a problem that maintenance work to remove clogging occurs. It was.

Also, in the cyclone separation device, the traveling direction of the swirling airflow was reversed on the outside and inside of the inner tube, and the air turbulence increased near the end of the inner tube, and the pressure loss increased. In order to suppress the turbulence of the air, a collar-like ring is provided on the outer peripheral surface side of the inner tube near the tip of the inner tube, or the cross section is circular along the outer wall circumferential direction of the inner tube at the end of the inner tube There is a method of providing a ring having a shape. Thereby, the turbulence of the air at the end when the traveling direction of the swirling airflow is reversed between the outside and the inside of the inner tube is suppressed, and the pressure loss is reduced. However, these methods have been difficult to put into practical use as ventilation hoods.

In the vent hood with the function of separating foreign matter using the cyclone technology as in the above-mentioned Patent Document 3, if there are many gaps in the separation chamber for separating foreign matters, the outside air enters the inside from the gap, and the gap A flow toward the outlet is generated. Since this flow is in the opposite direction to the direction in which the foreign matter moves from the swirl chamber to the separation chamber, the foreign matter prevents the foreign matter from moving into the separation chamber, and the foreign matter enters the room from the outlet without being separated. There was also.

SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and an object thereof is to provide a vent hood that can separate small insects, water droplets and the like (hereinafter, foreign matter) and does not require maintenance work. .

In order to achieve this object, the vent hood according to the present invention includes a cover having a rotating body shape in which an airflow flows in from a side surface portion and flows out from a bottom surface portion, and includes a central axis of the cover. A cylindrical tube provided so that the inside of the cover can be made negative pressure through the bottom surface of the cover, and a space for the first swirl chamber and the second swirl chamber on the outer peripheral side of the cylindrical tube and the inner peripheral side of the cover, respectively. A space dividing plate to be formed; and a columnar member provided to face the end surface of the cylindrical tube in the first swirl chamber. The cover has a top surface facing the bottom surface portion, a first air supply port is provided on the bottom surface side of the side surface portion, and a second air supply port is provided on the top surface side of the side surface portion. The first air supply port is a plurality of openings formed by a plurality of fixed blades arranged so as to go around the side surface portion. The second air supply port is an opening that is vertically long along the central axis direction and can be positioned at the lowermost portion of the side surface portion in a state where the central axis is horizontally disposed. The space dividing plate has a through hole that communicates the first swirl chamber and the second swirl chamber. The position of the through hole is such that the distance in the flow direction of the airflow swirling in the first swirl chamber is longer than the distance in the counterflow direction when the second air supply port is the base point around the central axis. is there. This achieves the intended purpose.

The outdoor air that has entered through the first air supply port flows into the first swirl chamber as a swirling airflow. The foreign matter contained in the swirling airflow receives centrifugal force, circulates in the vicinity of the space dividing plate, and moves to the second swirling chamber through a through hole provided in the space dividing plate. A natural wind is flowing around the vent hood, the static pressure decreases outside the second air supply port, a flow toward the outside occurs, and the foreign matter stored in the second air supply port, which is the separation chamber Is discharged to the outside from the second air supply port. That is, the effect that the foreign matter can be separated without providing a filtering device is obtained, the occurrence of clogging is eliminated, and the separated foreign matter does not continue to accumulate, so that maintenance work is not required. The effect that can be obtained.

FIG. 1 is an external perspective view from above of a vent hood according to Embodiment 1 of the present invention. FIG. 2 is an external perspective view from below of the vent hood according to the first embodiment. FIG. 3 is a cross-sectional view taken along the central axis, showing the internal structure of the vent hood in the first embodiment. FIG. 4 is a rear view of the first embodiment with the base of the vent hood removed. FIG. 5 is a front view of the first embodiment with the cover of the vent hood removed. FIG. 6 is a diagram showing the shape of the water shielding member of the vent hood in the second embodiment. FIG. 7 is a view showing notches provided in the water shielding member of the vent hood in the third embodiment. FIG. 8 is an external perspective view of the vent hood according to the fourth embodiment as viewed from the front side. FIG. 9 is an external perspective view of the vent hood according to the fourth embodiment as viewed from the back side. FIG. 10 is a cross-sectional view along the central axis of the vent hood according to the fourth embodiment. FIG. 11 is a cross-sectional view of the inner tube of the vent hood in the fourth embodiment. FIG. 12 is an external perspective view of the airflow conversion member according to the fourth embodiment. FIG. 13 is a diagram showing the flow of the airflow when the inner tube in the description of the fourth embodiment does not change the axial sectional area. FIG. 14 is an external view of the vent hood according to the fifth embodiment as viewed from the top side. FIG. 15 is a cross-sectional view along the central axis of the vent hood according to the fifth embodiment. FIG. 16 is a partially enlarged view of a portion A in FIG. 14 of the ventilation hood according to the fifth embodiment. FIG. 17 is a cross-sectional view showing a conventional cyclone separator.

A vent hood according to claim 1 of the present invention includes a cover having a rotating body shape in which an airflow flows in from a side surface portion and flows out from a bottom surface portion, and includes a central axis of the cover and penetrates the bottom surface portion from the inside of the cover. A cylindrical tube provided so that the inside of the cover can be under negative pressure, and a space dividing plate that forms a space for a first swirl chamber and a second swirl chamber on the outer peripheral side of the cylindrical tube and the inner peripheral side of the cover, respectively And a columnar member provided to face the end face of the cylindrical tube in the first swirl chamber. The cover has a top surface facing the bottom surface portion, the first air supply port is provided on the bottom surface side of the side surface portion, the second air supply port is provided on the top surface side of the side surface portion, and the first air supply port is provided. The mouth is a plurality of openings formed by a plurality of fixed blades arranged so as to circulate around the side surface portion, and the second air supply port extends along the central axis direction in a state where the central axis is horizontally arranged. The opening is vertically long and can be positioned at the lowermost portion of the side surface. The space dividing plate has a through hole that communicates the first swirl chamber and the second swirl chamber, and the position of the through hole is the first swirl when the second supply port is the base point around the central axis. It has a configuration in which the distance in the flow direction of the airflow swirling through the chamber is longer than the distance in the counterflow direction.

As a result, for example, the blower communicating with the cylindrical tube can make the inside of the cover have a negative pressure, so that outdoor air that has entered through the first air supply port flows into the first swirl chamber as a swirling airflow. . Here, the foreign matter contained in the swirling airflow receives centrifugal force, circulates in the vicinity of the space dividing plate, and moves to the second swirling chamber from the through hole provided in the space dividing plate. That is, the second swirl chamber is a separation chamber for receiving the separated foreign matter. The foreign matter moves under the second swirl chamber, which has become a separation chamber, due to gravity and near the second air supply port. The foreign matter that has moved to the second air supply port is discharged from the second air supply port to the outside due to the influence of outdoor natural wind.

Also, since the inside of the cover is under negative pressure, air usually flows from the second air supply port.

Since a part of the swirling airflow in the first swirl chamber flows into the second swirl chamber through the through hole with directivity, the airflow in the second swirl chamber is in the same swirling direction as the airflow in the first swirl chamber, and The airflow flowing in from the air mouth turns on the swirling airflow. As a result, foreign matter that has moved from the first swirl chamber to the second swirl chamber and foreign matter that has flowed into the second swirl chamber from the second air supply port can be moved to the outer peripheral side of the second swirl chamber. Since movement from the through hole to the first swirl chamber can be suppressed, a decrease in separation performance can be suppressed.

In the vent hood according to claim 2 of the present invention, the space dividing plate has a cylindrical shape or a truncated cone shape arranged on the top surface side of the first air supply port in the central axis direction. You may have the structure by which the end surface of the cylindrical tube was extended in the axial direction at the inner peripheral side of the space division | segmentation board.

As a result, while the air and foreign matter flowing in from the first air supply port swirl, the traveling direction once becomes the top surface side direction of the cover, and the traveling direction of the swirling flow is reversed on the top surface side and flows into the cylindrical tube. It becomes. Thereby, since the distance in the traveling direction of the swirl flow can be earned, the foreign matter can be sufficiently moved to the outer peripheral side by the centrifugal force, and the separation performance can be improved.

Moreover, the ventilation opening hood which concerns on Claim 3 of this invention is the 1st shielding member standingly arranged so that a part of flow path of the airflow in a 2nd swirl chamber might be interrupted | blocked on the space division board in the 2nd swirl chamber. The first shielding member may be provided on the through hole side from the line connecting the central axis and the second air supply port, and may extend from the central axis side to the outer peripheral side of the space dividing plate. Good.

This can suppress a decrease in the separation performance of foreign matter. That is, the foreign matter separated into the second swirl chamber moves to the vicinity of the second air supply port due to gravity, but rises by the air flowing in from the second air supply port. However, since the soaring foreign matter collides with the first shielding member and loses momentum, the foreign matter is prevented from moving toward the through hole side, flowing into the first swirl chamber from the through hole, and scattering downstream. Further, by providing the first shielding member, the air flowing in from the second air supply port can be directed in the direction opposite to the first shielding member. Therefore, the swirl flow in the second swirl chamber can be strengthened, foreign matter in the second swirl chamber can be prevented from flowing into the first swirl chamber from the through hole, and the reduction in separation performance can be suppressed.

The vent hood according to claim 4 of the present invention is a second shielding member that is erected on the space dividing plate so as to block a part of the flow path of the airflow in the second swirl chamber in the second swirl chamber. The second shielding member is provided above the central axis when the second air supply port is positioned at the lowest position, and has a configuration extending from the central axis side to the outer peripheral side of the space dividing plate. You may do it.

This can suppress a decrease in the separation performance of foreign matter.

The upper part of the second swirl chamber has a flow in the same direction as the flow direction of the airflow swirling in the first swirl chamber. When there is no second shielding member, among the foreign substances that move along the flow in the second swirl chamber, the foreign substances that move along the surface of the space dividing plate flow into the first swirl chamber as they are through the through hole. , Scattered to the downstream side, causing a reduction in separation performance. Therefore, the second shielding member can prevent the movement of the foreign matter on the surface of the space dividing plate, prevent the inflow from the through hole to the first swirl chamber, and suppress the decrease in the separation performance.

In the vent hood according to claim 5 of the present invention, in the state where the second air supply port is positioned at the lowermost part of the side surface of the cover, one opening of the first air supply port is formed at the upper and lower portions of the cover. And a blind plate may be arranged between the other openings.

This makes it possible to suppress the inflow of foreign matter and water droplets falling from directly above the vent hood because the slats are arranged on the top of the cover. In addition, since the slab is disposed at the lower part of the cover, the foreign matter discharged from the second air supply port to the outside can be prevented from flowing again from the first air supply port, and the decrease in separation performance can be suppressed.

In the vent hood according to claim 6 of the present invention, in the first swirl chamber, the columnar member is erected from the wall surface on the top surface side, and a ring-shaped water shielding member surrounding the outer periphery of the columnar member is provided on the wall surface. You may have the structure comprised.

Thereby, it is possible to suppress water droplets flowing from the first air supply port from being scattered downstream of the ventilation port hood. The water droplets swirl on the swirl flow in the first swirl chamber and receive centrifugal force like the foreign matter. When the water droplets moved to the outer peripheral side collide with the space dividing plate, they adhere to the surface. Some of the attached water droplets move downward due to gravity, and some of them collide with the cylindrical member and scatter along the cylindrical member surface into the cylindrical tube. Therefore, by providing a ring-shaped water-impervious member so as to surround the periphery of the cylindrical member, it is possible to suppress water droplets from being transmitted to the cylindrical member, and it is possible to suppress deterioration of water droplet separation performance.

Moreover, even if the ventilation opening hood which concerns on Claim 7 of this invention has a structure which provided the inclination in the side surface by the side of a cylindrical member so that water might flow out from the inner side of a water-impervious member to the outer side. Good.

This makes it easier for the water droplets that have entered the inside of the water-impervious member to move downward due to gravity and then move outward due to the inclination provided on the inner side surface of the water-impervious member, thereby preventing the water droplets from being transmitted to the cylindrical member It is possible to suppress a drop in water droplet separation performance.

Further, the vent hood according to claim 8 of the present invention may have a configuration in which the water shielding member has a notch at the lowest position in a state where the central axis is horizontally disposed.

This makes it easier for water droplets that enter the inside of the water-impervious member to move downward due to gravity and then move from the notch to the outer side of the water-impervious member, thereby preventing the water droplets from being transmitted to the cylindrical member. It is possible to suppress a drop in water droplet separation performance.

Further, in the vent hood according to claim 9, the cylindrical tube includes an inner tube extending from the outlet provided in the bottom surface portion into the first swirl chamber, and is an inner tube that is a tip of the inner tube. The end portion of the cylindrical wall that forms the tip opening has a flow path that reverses the traveling direction of the swirling airflow flowing in from the first air supply opening on the outside and inside of the inner tube, and is perpendicular to the central axis of the inner tube. The cross-sectional area on the surface changes in the direction of the central axis, and the cross-sectional area is minimized at the end of the cylindrical wall from the middle position of the entire length of the inner tube, and the minimum cross-sectional area of the inner tube You may have the structure which was made to become large gradually toward the cylindrical wall edge part side from this position.

As a result, it is possible to suppress the phenomenon of air separation that occurs toward the downstream side starting from the end portion of the inner cylindrical tube front end port, and to suppress energy loss of air flowing from the inner cylindrical tube front end port to the downstream side. Therefore, the pressure loss of the apparatus can be reduced.

The vent hood according to claim 10 is provided with an R-shaped portion that bulges out toward the outside of the inner tube at the end of the cylindrical wall, and the inner and outer surfaces of the inner tube are R You may have the structure that it connects with the circular arc continuously along the shape part.

Thereby, even if the direction of the swirling airflow is different between the outside and the inside of the inner tube, it is possible to suppress the separation of the air generated at the end of the cylindrical wall, and the energy loss of the air that tends to flow into the inner tube Therefore, the pressure loss of the apparatus can be reduced.

In the vent hood according to claim 11, an R-shaped portion that bulges out toward the outside of the inner tube is provided at the end of the cylindrical wall, and the outer surface of the inner tube is formed on the surface of the R-shaped portion. The groove may be formed over the entire circumference.

As a result, water droplets that have entered from the first air supply port, which is an inflow port, are prevented from flowing into the inner peripheral surface of the inner cylindrical tube through the outer peripheral surface of the inner cylindrical tube without increasing pressure loss. can do. When water droplets are transmitted through the R-shaped part, they are trapped in the groove part, moved downward by gravity, and dropped downward from the lowermost part of the groove part, so that water droplets are prevented from flowing into the inner peripheral surface of the inner tube. Can do.

In the vent hood according to claim 12, the diameter of the tip end of the inner tube is φin, the diameter of the minimum cross-sectional area of the inner tube is φmin, and the diameter of the end on the outlet side of the inner tube is φout. In this case, a relationship of φin> φout> φmin may be established, and φmin = (0.75 to 0.85) × φin may be provided.

This makes it possible to determine the optimum shape of the inner tube that reduces the pressure loss, and to reduce the pressure loss to the maximum.

The vent hood according to claim 13 of the present invention is a cover having a rotating body shape in which airflow flows in from a side surface portion and flows out from a bottom surface portion, an opening that closes the bottom surface portion and is an airflow outlet in the center portion. A base plate, a space dividing plate that divides the inside of the cover into a first swirl chamber on the inner periphery side and a second swirl chamber on the outer periphery side, and penetrates the base plate, and the first swirl chamber and the outside A cylindrical tube provided in communication therewith. The cover has a top surface facing the bottom surface portion, and a first air supply port having a structure capable of generating a swirling airflow in the first swirl chamber is provided on the bottom surface portion side of the side surface portion. A second air supply port that communicates the second swirl chamber and the outside is provided on the surface side. The first air supply port is connected to the bottom surface side of the cover. The cylindrical tube extends from the base plate into the first swirl chamber, and has an inner cylindrical tube front end through which air flows into the first swirl chamber, and an outlet through which air flows into the bottom surface. The space dividing plate has a through hole for communicating the first swirl chamber and the second swirl chamber, and a ring-shaped contact surface on the outer peripheral portion on the bottom surface portion side. The contact surface is a conical surface whose diameter decreases toward the top surface, and the contact surface and the inner peripheral surface of the cover are in close contact with each other through packing.

As a result, in the second swirl chamber, which is a space surrounded by the space dividing plate and the cover, a gap is filled between the contact surface and the cover by the packing, so that outside air is generated between the space dividing plate and the cover. Inflow into the second swirl chamber is suppressed, and a decrease in separation performance can be suppressed.

Further, the contact surface is a conical surface, that is, an inclined surface whose diameter on the top surface side is reduced, so that the contact area with the packing is increased, and the outside air is reliably prevented from flowing into the separation chamber. be able to.

In addition, when the contact surface is inclined, when assembling the ventilation hood, the space dividing plate is inserted into the cover after the packing is attached to either the cover or the contact surface. However, in either case, the packing is smoothly fitted by the effect of the inclination, and the sealing property can be easily obtained.

In the vent hood according to claim 14, the packing is affixed to the inner side surface of the cover, and a flange portion projecting to the outer peripheral side is provided on the bottom surface side of the space dividing plate. A plurality of fixed blades are erected on the bottom surface side of the flange portion, the fixed blades are integrated with the space dividing plate, and the outer peripheral end of the flange portion is provided with a contact rib protruding to the top surface side, The outer peripheral surface of the contact rib may be a contact surface.

Thereby, the gap between the fixed blade and the space dividing plate can be eliminated by integrating the fixed blade and the space dividing plate. If there is a gap between the fixed vane and the space dividing plate, an airflow passing through the gap is generated without passing through the fixed vane for swirling the airflow. Becomes weaker, the centrifugal force applied to the foreign matter is weakened, and the separation performance of the foreign matter is lowered.

Also, since the fixed blade and the space dividing plate are integrated, the extra space can be reduced compared to the case of using separate members, which leads to downsizing of the vent hood.

Even in such a configuration, when the space dividing plate integrated with the fixed blade is incorporated into the cover, the contact rib is inclined as a conical surface, so that the packing attached to the inner surface of the cover is gradually removed. Will be pressed against. Therefore, the packing can be smoothly fitted, sealing can be easily obtained, and a decrease in separation performance can be suppressed.

In the vent hood according to claim 15, the space dividing plate may have a truncated cone shape whose diameter decreases toward the top surface so as to be in the same inclination direction as the contact surface.

Thereby, even if the swirling airflow in the first swirl chamber moves away from the first air supply port, and the flow velocity of the swirling airflow decreases, the inside of the first swirl chamber moves toward the top surface away from the first air supply port. The diameter is smaller. Therefore, the fall of the centrifugal force concerning a foreign material can be suppressed. Thereby, the fall of separation performance can be controlled.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is an external perspective view from above of a vent hood according to Embodiment 1 of the present invention. In addition, FIG. 1 is the external appearance (perspective view from diagonally above) when looking down from the upper side of the outdoor side when attached to the outer wall of the house on the front side of the vent hood 1. The central axis 4 is horizontal.

FIG. 2 is an external perspective view from below of the vent hood according to the first embodiment. In addition, FIG. 2 is the external appearance (perspective view from diagonally below) seen when looking up from the lower part of the outdoor side. FIG. 3 is a cross-sectional view taken along the central axis of the vent hood in the first embodiment. FIG. 4 is a rear view of the first embodiment with the base of the vent hood removed. FIG. 5 is a front view of the first embodiment with the cover of the vent hood removed.

The ventilation hood 1 is attached to an air supply opening that is an air intake provided on the outer wall of the house when outdoor air is taken into the house. And the ventilation opening hood 1 is connected to the air blower installed in the house through a ventilation duct, takes in outdoor air, and supplies it indoors.

As shown in FIGS. 1 and 2, the vent hood 1 includes a cover 2 having a rotating body shape at least on the inside, a base plate 3 that forms the bottom surface of the cover 2, and a central axis 4 of the cover 2. And a cylindrical tube 5 fixed so as to penetrate therethrough. Here, the rotating body shape is a shape formed by rotating around the central axis 4. Further, the airflow flows from the side surface portion 7 of the cover 2 and flows out from the bottom surface portion of the cover 2.

A dome-shaped top surface 6 for projecting the cover 2 outward is provided on the front side of the vent hood 1, that is, on the surface opposite to the base plate 3 that is the bottom surface portion. Further, the most protruding portion of the top surface 6 coincides with the central axis 4. Note that the shape of the cover 2 is not limited to the dome shape, and may be a cylindrical shape. That is, the top surface 6 may be flat.

The side surface portion 7 of the cover 2 is provided with a first air supply port 8, a blind plate 9 that covers a part of the first air supply port 8, and a second air supply port 10.

The first air supply port 8 is a plurality of openings formed by a plurality of fixed blades 11 arranged at predetermined intervals so as to circulate around the side surface portion 7. In the present embodiment, 20 fixed blades 11 are provided and all face the same angle with respect to the central axis 4. Thereby, the airflow that has passed through the fixed blade 11 becomes a swirling airflow. The first air supply port 8 is provided in the side surface portion 7 and particularly at a position close to the base plate 3 side. That is, the first air supply port 8 is provided on the bottom surface side of the ventilation port hood 1.

The upstream end 12 of the fixed blade 11 is arranged on the same surface as the side surface 7 of the cover 2 in FIG. May be arranged.

The blind plate 9 is to suppress the inflow of airflow at the upper and lower portions of the first air supply port 8. The cover 2 does not have the fixed blades 11 provided on the blind plate 9, but the fixed blades 11 may also be provided on the inner side of the blind plate 9. The blind plate 9 is configured to be disposed between one opening of the first air supply port 8 and the other opening.

The blind plate 9 also has a role of connecting the base plate 3 and the cover 2. Thereby, since the base plate 3, the cylindrical tube 5, and the cover 2 are integrated, the ventilation port hood 1 can be fixed to the building outer wall by inserting the cylindrical tube 5 into the ventilation port of the building outer wall.

The cylindrical tube 5 is provided so that the inside of the cover 2 can be made negative pressure outside the vent hood 1. For example, by connecting a blower (not shown) to the cylindrical tube 5, the inside of the cover 2, that is, the inside of the vent hood 1 can be set to a negative pressure. Thus, by making the inside of the cover 2 have a negative pressure, air flows in from the side surface portion 7 of the cover 2 and flows out of the cylindrical tube 5. As shown in FIG. 3, the cylindrical tube 5 includes the central axis 4 of the cover 2 and is provided so as to penetrate the bottom surface from the inside of the cover 2.

The second air supply port 10 is provided at the lowermost portion of the side surface portion 7 on the top surface 6 side as shown in FIG. In the present embodiment, the shape of the second air supply port 10 is a vertically long shape in the direction along the central axis 4. The second air supply port 10 is provided in the side surface portion 7 at a position adjacent to the lower blind plate 9 in the direction along the central axis 4. The second air supply port 10 may not be completely adjacent to the blind plate 9, and there may be a gap between the second air supply port 10 and the blind plate 9. In the present embodiment, the second air supply port with respect to the opening area of the first air supply port 8 (the opening area here is calculated from the circumferential length of the side surface portion 7 and the opening width in the direction of the central axis 4). The opening area of 10 is about 0.6%, which is very small with respect to the first air inlet 8.

Next, the internal structure of the vent hood 1 in the present embodiment will be described.

As shown in FIG. 3, a space dividing plate 13 and a cylindrical member 14 are provided inside the cover 2.

The space dividing plate 13 forms spaces for forming the first swirl chamber 15 and the second swirl chamber 19 on the outer peripheral side of the cylindrical tube 5 and the inner peripheral side of the cover 2, respectively.

It can also be said that the space dividing plate 13 divides the inside of the cover 2 into an inner circumferential first swirl chamber 15 and an outer circumferential second swirl chamber 19.

The columnar member 14 is a columnar body having the same axis as the central axis 4 of the cover 2 in the first swirl chamber 15, and is provided at a position facing the end surface of the cylindrical tube 5 using the fixed plate 16. . Here, the fixing plate 16 is provided on the top surface 6 side in the cover 2. In this embodiment, the columnar member 14 is supported using the fixed plate 16, but the columnar member 14 may be directly fixed to the inner wall of the cover 2 without using the fixed plate 16.

As shown in FIG. 4, four cylindrical blades 17 that are curved in an arc shape in a cross section perpendicular to the central axis 4 are arranged uniformly and radially on the cylindrical tube 5 side of the cylindrical member 14.

The cylindrical tube end surface 18 which is an end surface located inside the cover 2 of the cylindrical tube 5 extends into the space dividing plate 13 as shown in FIG.

As shown in FIG. 3, the space dividing plate 13 is a cylinder that extends further in the direction of the central axis 4 from the position sandwiching the fixed blade 11 with respect to the base plate 3 in the direction of the central axis 4. And the fixed plate 16 is arrange | positioned at the top surface 6 located in the extended termination | terminus. That is, the space dividing plate 13 is a cylindrical body having a trapezoidal cross section in the direction of the central axis 4 inside the cover 2. Due to the shape of the truncated cone, the swirling diameter of the swirling flow swirling in the first swirling chamber 15 decreases as the distance from the first air supply port 8 side increases in the direction of the central axis 4. The space dividing plate 13 may be cylindrical. In this case, the swirl diameter of the swirl flow swirling in the first swirl chamber 15 is the same at any location.

As shown in FIG. 5, the space dividing plate 13 is provided with a through hole 21 that communicates the first swirl chamber 15 and the second swirl chamber 19. The space dividing plate 13 includes a first shielding member 22 and a second shielding member 23 arranged on the second swirl chamber 19 side.

As shown in FIG. 4, the through-hole 21 is a distance in the flow direction (arrow in FIG. 4) of the airflow that swirls around the first swirl chamber 15 around the central axis 4 when the second air supply port 10 is the starting point. Is longer than the distance in the counter-flow direction, and is provided close to the fixed plate 16 side above the central axis 4. In FIG. 3, the through hole 21 does not overlap with the cylindrical tube 5, but the through hole 21 may be extended in the direction of the central axis 4 to an overlapping position. Further, the through hole 21 may be opened over the entire region of the space dividing plate 13 in the direction of the central axis 4.

The first shielding member 22 extends in the vicinity of the second air inlet 10 in the second swirl chamber 19 from the center side to the outer peripheral side on the through hole 21 side from the line connecting the central shaft 4 and the second air inlet 10. This is a plate-like body. As shown in FIG. 3, a gap is provided between the first shielding member 22 and the cover 2 so that a part of the flow path in the second swirl chamber 19 is shielded.

The second shielding member 23 is a plate-like member extending from the center side to the outer peripheral side at the uppermost part in the second swirl chamber 19 in the state where the second air inlet 10 shown in FIG. . Similar to the first shielding member 22, a part of the flow path in the second swirl chamber 19 is shielded, and a gap is provided between the second shielding member 23 and the cover 2. In addition, the 2nd shielding member 23 does not need to be provided in the uppermost part in the 2nd turning chamber 19. FIG. Specifically, the second shielding member 23 only needs to be provided above the central axis 4.

Further, the fixing plate 16 is provided with a water shielding member 25.

The water-impervious member 25 is a rib-like member that surrounds the cylindrical member 14 with a gap from the side surface of the cylindrical member 14. The water-impervious member 25 in the present embodiment is a ring shape having a continuous circumferential shape, and its side surface is parallel to the columnar member 14. In addition, if the space | interval of the side surface of the cylindrical member 14 and the water shielding member 25 is opened too much, the water shielding effect will become small. Therefore, the water shielding member 25 is preferably arranged at a position smaller than the average diameter of the end of the space dividing plate 13 on the top surface 6 side of the cover 2 and the diameter of the cylindrical member 14. That is, the diameter of the water shielding member 25 is preferably smaller than the average diameter of the end of the space dividing plate 13 on the top surface 6 side and the diameter of the columnar member 14.

Next, the flow of the airflow will be explained.

In the above configuration, the vent hood 1 is attached to the air supply port portion of the outdoor outer wall when supplying the outdoor air into the house or the like using a blower, and the airflow flows by the downstream blower. Outdoor air flows into the vent hood 1 from the first air inlet 8 and the second air inlet 10. As described above, since the opening area of the first air supply port 8 is much larger than the opening area of the second air supply port 10, most of the inflow air flows from the first air supply port 8. The air flowing in from the first air supply port 8 becomes a swirling airflow swirling around the central axis 4 by a plurality of obliquely arranged fixed blades 11, passes through the first swirling chamber 15, and is ventilated from the cylindrical tube 5. It flows out of the mouth hood 1.

The air flowing in from the second air supply port 10 flows into the second swirl chamber 19, but the flow of the airflow is suppressed by the first shielding member 22 shown in FIG. Therefore, most of the air that flows in from the second air supply port 10 flows toward the side opposite to the first shielding member 22, passes through the annular second swirl chamber 19, and passes through the through hole 21 to form the first swirl chamber. Flow into. Thereafter, the air flowing into the first swirl chamber 15 flows out of the vent hood 1 from the cylindrical tube 5. A part of the swirl flow in the first swirl chamber 15 flows into the second swirl chamber 19 from the through hole 21. The directional airflow flowing from the first swirl chamber 15 to the second swirl chamber 19 and the directivity flowing from the second swirl chamber 19 to the first swirl chamber 15 by the first shielding member 22 described above. Due to the air flow, the air in the second swirl chamber 19 swirls in the same direction as the air in the first swirl chamber 15.

Next, the movement of foreign matter (for example, small insects such as mosquitoes, fruit flies, mushrooms, and moths) and water droplets flowing into the vent hood 1 together with air will be described.

The foreign matter that flows in with the air from the first air supply port 8 receives centrifugal force due to the swirling flow in the first swirling chamber 15 and moves to the outer peripheral side of the first swirling chamber 15. The foreign matter that has moved to the outer peripheral side of the first swirl chamber 15 moves to the second swirl chamber 19 through the through hole 21 and is temporarily stored in the second swirl chamber 19.

Further, the water droplets flowing in along with the air from the first air supply port 8 move to the outer peripheral side in the first swirl chamber 15 like the foreign matter. Then, it collides with the wall surface of the space dividing plate 13 and adheres to the wall surface. The adhering water droplets gather together and become larger, and sag due to gravity.

The foreign matter and water droplets that have flowed in from the second air supply port 10 are swirled by the swirling flow in the second swirl chamber 19, receive centrifugal force, and move to the outer peripheral side. The air in the second swirl chamber 19 flows from the through hole 21 to the first swirl chamber 15, but the foreign matter swirls on the outer peripheral side, so that it is difficult to flow into the first swirl chamber 15 from the through hole 21. The water droplets adhere to the wall surface of the second swirl chamber 19, drop downward due to gravity, and are discharged from the second air inlet 10.

As described above, the foreign matter is stored in the second swirl chamber 19, but is discharged from the second air supply port 10 by natural wind flowing outside the vent hood. That is, when natural wind flows outside the second air inlet 10, the static pressure decreases according to Bernoulli's theorem. At this time, when the pressure falls below the static pressure in the ventilation port hood 1 near the second air supply port 10, the foreign matter is pulled out and is discharged from the second air supply port 10 to the outside of the ventilation port hood 1.

Next, effects and operations in this embodiment will be described.

The characteristic structure of the vent hood 1 in the present embodiment is that the vent hood 1 has a double structure consisting of a first swirl chamber 15 and a second swirl chamber 19 by a space dividing plate 13. It is. As described above, the second swirl chamber 19 serves as a separation chamber that temporarily stores the foreign matter separated by the centrifugal force in the first swirl chamber 15. Since the general cyclone structure has a separation chamber (dust collection chamber) below the swirl chamber, it becomes longer vertically, but the vent hood 1 in the present embodiment is a first swirl that is a swirl chamber. By providing the second swirl chamber 19 which is a separation chamber around the chamber 15, a compact structure is obtained.

As the name of the second swirl chamber 19, the separation chamber of the vent hood 1 in the present embodiment has a structure that swirls the airflow by the inflow of swirl flow from the through hole 21 and the first shielding member 22. . Thereby, since the foreign material in the second swirl chamber 19 moves to the outer peripheral side, the foreign material rarely returns from the through hole 21 to the first swirl chamber 15. In the case of a large foreign object that cannot move to the outer peripheral side, it moves while being pushed by the swirling flow along the space dividing plate 13. In this case, since it collides with the second shielding member 23 at the upper part of the second swirling chamber 19, It cannot proceed further and does not flow to the through hole 21 side. That is, it is possible to prevent a large foreign object that is difficult to work with centrifugal force from flowing into the first swirl chamber 15.

The position of the through hole 21 is arranged at a suitable position in the present embodiment in order to enhance the separation performance of the foreign material and prevent the foreign material from flowing into the first swirl chamber 15 from the second swirl chamber 19. The foreign matter swirls within the first swirl chamber 15 and receives a force that moves to the outer peripheral side due to centrifugal force. However, while the foreign matter swirls downward from the upper part of the first swirl chamber 15, the second swirl chamber 19. When you move to, the force by gravity is also combined. Thereby, even after the foreign matter moves to the second swirl chamber 19, it can be quickly moved to the lower part of the second swirl chamber 19 by the inertial force and gravity due to the swirl. This effect is most apparent at the position in the present embodiment. Furthermore, in order to allow a large amount of foreign matter to be stored in the second swirl chamber 19, it may be better to position the through hole 21 on the upper side, so the through hole 21 is disposed above the central axis 4. is doing.

As shown in FIG. 5, the second shielding member 23 is desirably arranged at the uppermost part of the second swirl chamber 19. Since the uppermost portion is the uppermost portion of the frustoconical space dividing plate 13, the space dividing plate 13 is inclined downwardly on either surface of the second shielding member 23, and foreign matter accumulates. It becomes difficult.

If foreign matter enters the first swirl chamber 15 from the second swirl chamber 19 through the through hole 21, it collides with the side surface of the cylindrical member 14 when moving from the through hole 21 toward the central axis 4 direction. To do. Therefore, it is difficult for foreign matter to flow directly into the cylindrical tube 5. The vicinity of the central axis 4 in the first swirl chamber 15 is a swirl flow toward the cylindrical tube 5, but the columnar member 14 is a barrier. Therefore, the foreign matter flowing in from the through hole 21 is prevented from directly entering the swirling flow in the vicinity of the central axis 4, and the foreign matter is prevented from scattering downstream.

Further, foreign matter in the second swirl chamber 19 often exists near the second air inlet 10 due to gravity. For this reason, when air flows in from the second air supply port 10, the foreign matter soars. However, at that time, the movement of the foreign matter is limited by the first shielding member 22 so that the foreign matter does not move to the through hole 21 side (left side in FIG. 5) and flow into the first swirl chamber 15 from the through hole 21. Yes. As a result, foreign matter that has been swollen by the air flowing in from the second air supply port 10 is prevented from flowing into the first swirl chamber 15 from the through hole 21.

Since the vent hood 1 can discharge the separated foreign matter again to the outdoors, no maintenance is required. As described above, the foreign matter once separated and stored in the second swirl chamber 19 is discharged to the outside from the second air supply port 10 by natural wind, so that the foreign matter continues to accumulate in the vent hood 1. There is no.

As shown in FIG. 3, the cylindrical tube 5 is arranged such that the end surface 18 of the cylindrical tube extends into the space dividing plate 13. That is, the cylindrical tube 5 that is an outlet, the first swirl chamber 15 that is a swirl chamber, and the second swirl chamber 19 that is a separation chamber (dust collection chamber) are simultaneously overlapped. According to this structure, the ventilation opening hood 1 can be made into a compact structure.

In addition, since foreign matter and water droplets cannot flow directly into the cylindrical tube 5 from the first air supply port 8, it is difficult for the foreign matter and water droplets to be scattered downstream of the ventilation port hood 1, that is, compact and has good separation performance. Become.

The cylindrical member 14 prevents foreign matter flowing into the first swirl chamber 15 from the second swirl chamber 19 through the through-hole 21 and into the cylindrical tube 5 and suppresses a decrease in separation performance. The flow of airflow in the through-hole 21 includes both a flow from the first swirl chamber 15 to the second swirl chamber 19 and a flow in the opposite direction, but the flow flowing into the first swirl chamber 15 side is mainly. This occurs near the fixed plate 16 side. Therefore, even if the foreign matter flows into the first swirl chamber 15 side, it rebounds by colliding with the cylindrical member 14. The bounced foreign matter flows in the swirl flow in the first swirl chamber 15, receives centrifugal force by swirling, and can be moved again from the through hole 21 to the second swirl chamber 19, thus reducing the separation performance. Can be suppressed.

Furthermore, in the present embodiment, four circular arc-shaped cylindrical blades 17 are provided on the upper surface side (cylindrical tube 5 side) of the columnar member 14. The cylindrical blade 17 swells to receive the swirling flow in the first swirling chamber 15 indicated by the arrow in FIG. As a result, the swirl flow is converted into a flow in the downstream direction by the cylindrical blades 17 and air flows smoothly downstream, so that the pressure loss is reduced. That is, the cylindrical blade 17 has an effect of reducing the pressure loss of the vent hood 1. In addition, by visualization of the flow by fluid analysis, the flow of the swirling flow toward the downstream (in the direction of the cylindrical tube 5) is grasped, and the cylindrical member 14 has a diameter substantially equal to the diameter of the swirling flow toward the cylindrical tube 5. The diameter was determined. The diameter of the swirling flow toward the cylindrical tube 5 correlates with the inner diameter of the cylindrical tube 5, and the diameter of the swirling flow toward the cylindrical tube 5 is about 70 to 80% of the inner diameter of the cylindrical tube 5. It is.

The blind plate 9 is located above and below the first air inlet 8, and the upper blind plate 9 prevents rain falling from above or foreign matter falling from flowing into the first air inlet 8. effective. The lower blind plate 9 has an effect of preventing foreign matter discharged from the nearby second air inlet 10 from flowing again from the first air inlet 8. In this embodiment, both of the blind plates 9 also serve as support plates that connect the base plate 3 and the cover 2.

The cover 2 has a dome shape on the front side of the vent hood 1. As a result, the inside of the second swirl chamber 19 is inclined, and the separated foreign matter moves along the inclination and easily collects in the vicinity of the second air inlet 10. Further, since the shape of the second air supply port 10 is a vertically long shape that is long in the central axis direction, an opening is provided in the direction of the central axis 4 of the second swirl chamber 19. By these actions, foreign matter can be efficiently discharged from the second air supply port 10.

換気 Ventilation hood 1 is required to play a role in preventing water from entering the room when it rains. In the vent hood 1 in the present embodiment, the cylindrical pipe end surface 18 that is the end of the cylindrical pipe 5 connected to the room and the first air supply port 8 are not directly connected as described above. Inflow of water droplets is suppressed. Further, in the first swirl chamber 15, the water droplets move to the outer peripheral side due to the swirl flow and adhere to the wall surface of the space dividing plate 13. By these actions, the ventilation hood has a structure in which rain does not easily enter.

Furthermore, a water shielding member 25 is provided around the cylindrical member 14 in order to prevent water from entering. The water droplets adhering to the wall surface of the space dividing plate 13 move downward along the fixed plate 16 due to gravity. At this time, the water droplets colliding with the water shielding member 25 move downward along the water shielding member 25, so that the dripping water droplets do not reach the cylindrical member 14. Since a flow toward the cylindrical tube 5 is generated in the vicinity of the cylindrical member 14, water droplets attached to the cylindrical member 14 are likely to be scattered into the cylindrical tube 5. The water-impervious member 25 can suppress a drop in water droplet separation performance by preventing such water droplets from being scattered.

Also, the front of the vent hood 1 is covered with the cover 2 and there is no opening on the front side, so that the wind does not flow directly into the room.

As described above, the vent hood 1 has a foreign matter separation function using centrifugal force, and has a compact configuration and low pressure loss. Furthermore, in the vent hood 1, the separated foreign matter is discharged to the outside by the force of natural wind, and there is no narrow gap that causes clogging, so that the maintenance work of removing the foreign matter becomes unnecessary.

(Embodiment 2)
Next, another configuration example of the water shielding member will be described.

Description of parts having the same configuration and operation as the first embodiment will be omitted.

FIG. 6 is a diagram showing the shape of the water shielding member of the vent hood according to the second embodiment. FIG. 6 is a partially enlarged cross-sectional view of the water shielding member 125 in the second embodiment. The water-impervious member 125 in the present embodiment has an inclined surface so that the side surface on the central axis 4 side widens toward the cylindrical tube 5 side. As a result, when the water droplets that have entered the inner peripheral side of the water-impervious member 125 move downward due to gravity, the water droplets are not collected inside the water-impervious member 125 but are discharged outside the water-impervious member 125 along the inclined surface. Is done. Therefore, it is possible to prevent water droplets from being scattered downstream, so that it is possible to suppress a decrease in separation performance.

(Embodiment 3)
A description of portions having the same configuration and operation as those of the first embodiment will be omitted.

FIG. 7 is a front view showing the shape of the water-impervious member in the third embodiment. In the water-impervious member 225 in the present embodiment, a notch 226 is provided at a position located at the lowest part in the direction of gravity. Thus, when the water droplets that have entered the inner peripheral side of the water-impervious member 225 move downward due to gravity, the water droplets are not collected inside the water-impervious member 225 and are discharged from the notch 226 to the outside of the water-impervious member 225 The Therefore, it is possible to prevent water droplets from being scattered downstream, so that it is possible to suppress a decrease in separation performance.

(Embodiment 4)
Next, in the present embodiment, a mode in which pressure loss can be further reduced without increasing the size of the apparatus and without reducing the separation performance of foreign matters will be described. In addition, about the structure already demonstrated in description of Embodiment 1-3, in order to avoid duplication, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.

FIG. 8 is an external perspective view of the vent hood according to the fourth embodiment as viewed from the front side. In addition, FIG. 8 is the external appearance which looks when it looks down from upper direction of the outdoor side, when it attaches to a house outer wall in the front side of the ventilation opening hood 300. FIG. FIG. 9 is an external perspective view of the vent hood according to the fourth embodiment as viewed from the back side. FIG. 9 is a view of the rear side of the vent hood 300 as viewed from the outer wall side of the house. FIG. 10 is a cross-sectional view along the central axis of the vent hood according to the fourth embodiment.

As shown in FIG. 10, the cylindrical tube 5 includes an inner tube 330 that extends from the base plate 3 to the inside of the vent hood 300 and a connection tube 331 that extends to the outside of the vent hood 300. In the present embodiment, the features of the inner tube 330 extending inward from the base plate 3 will be described. Details of the inner tube 330 will be described later.

10, the vent hood 300 can be connected to a ventilation duct embedded in the outer wall of the house using a connecting pipe 331 indicated by a dotted line.

As shown in FIGS. 8 and 9, the ventilation port hood 300 includes a cover 2 and a base plate 3 that is a bottom surface of the cover 2. The vent hood 300 is provided with a slat 9 on the side surface of the cover 2 so as to bend along the circular shape of the cover 2.

The cover 2 and the base plate 3 are connected via a blind plate 9. As a result, a gap is provided between the cover 2 and the base plate 3 to form the first air supply port 8. The first air inlet 8 is configured to be in contact with the base plate 3 on the side surface of the vent hood 300 and is formed over 360 degrees, but air does not flow into the blind plate 9 portion.

The first air supply port 8 is provided with a plurality of fixed blades 11 arranged obliquely toward the central axis 4 so that the inflowing air turns.

As shown in FIG. 8, a second air inlet 10 is provided in a portion located at the lower part of the cover 2.

As shown in FIG. 9, a circular opening is provided in the center of the base plate 3, and this opening serves as an air outlet 332.

Next, the internal configuration of the vent hood 300 according to the present embodiment will be described with reference to FIG.

The inner side of the cover 2 is divided into a first swirl chamber 15 and a second swirl chamber 19 by a space dividing plate 13. In the cross section crossing the central axis 4, the second swirl chamber 19 is annular and surrounds the first swirl chamber 15. That is, the inner periphery side of the cover 2 is the first swirl chamber 15, and the outer periphery side of the cover 2 is the second swirl chamber 19. A through hole 21 is provided in the space dividing plate 13, and the first swirl chamber 15 and the second swirl chamber 19 are spatially connected via the through hole 21.

An outlet 332 is provided at the center of the base plate 3. The outlet 332 has a circular shape, and its center overlaps the central axis 4. The inner tube 330 is provided so as to extend from the outlet 332 into the first swirl chamber 15. In the cross-sectional view of FIG. 10, the inner cylindrical tube 330 overlaps the fixed blade 11, and the inner cylindrical tube distal end 333 of the inner cylindrical tube 330 into which the air in the first swirl chamber 15 flows further overlaps the space dividing plate 13. It is extended to.

The columnar member 14 is provided at a position facing the inner tube 330 on the top surface 6 side in the first swirl chamber 15. A ring-shaped water shielding member 25 is provided around the cylindrical member 14 on the top surface 6 side in the first swirl chamber 15.

As shown in FIG. 10, the space dividing plate 13 has a cross-sectional area of the first swirl chamber 15 (from the end of the first air supply port 8, that is, the end of the fixed blade 11 toward the top surface 6 of the cover 2). The central axis 4 and the vertical plane are inclined so as to be small. The second swirl chamber 19 is a space formed in the gap between the space dividing plate 13 and the cover 2.

When the central shaft 4 is in a horizontal state, the second air supply port 10 is an opening provided on the side surface of the cover 2 so as to be positioned at the lower part in the gravity direction. The second air supply port 10 is a rectangular opening that is long in the direction of the central axis 4, and the outside and the second swirl chamber 19 are spatially connected.

The connecting pipe 331 is fixed to the base plate 3 and has a cylindrical shape having an inner diameter approximately the same size as the outflow port 332 (diameter). Moreover, the center of the connecting pipe 331 overlaps the central axis 4.

FIG. 11 is a cross-sectional view of the inner tube of the vent hood in the present embodiment. FIG. 11 is a cross-sectional view of the inner cylindrical tube 330 cut in the axial direction along a plane including the central axis 4.

The shape of the inner tube 330 is such that the cross-sectional area obtained by cutting the inner tube 330 along a plane perpendicular to the central axis 4 changes in the axial direction. Note that the inner diameter of the inner tube 330 that overlaps the outlet 332 has the same size as the diameter of the outlet 332. The diameter of this portion, that is, the outlet 332 is defined as a diameter φout. Further, the diameter at the position where the cross-sectional area of the inner tube 330 is minimum, that is, the minimum diameter is defined as the minimum diameter φmin. Then, the diameter of the inner cylindrical tube tip 333 (located on the cylindrical tube end face 18), which is the inlet through which air first flows into the inner cylindrical tube 330, that is, the diameter of the inlet is defined as the diameter φin.

The position of the minimum diameter φmin in the direction of the central axis 4 is located between the intermediate position of the entire length (in the axial direction) of the inner cylindrical tube 330 and the distal end port 333 of the inner cylindrical tube. In addition, the diameter φin of the inner cylindrical tube distal end 333 is the largest, and the relationship of diameter φin> diameter φout> minimum diameter φmin is established.

A cylindrical wall end 334 that forms the inner tube pipe distal end 333 is an R-shaped portion 335 in which the outer side of the inner tube 330 bulges out roundly. Are connected.

A groove 337 is formed on the surface of the R-shaped portion 335 over 360 degrees with the central axis 4 as the center. The width of the groove 337 is 1/3 to 1/5 of the depth.

In the present embodiment, in order to attach the inner cylindrical tube 330 to the base plate 3, a flange 338 for fixing the base plate 3 is provided at the diameter φout portion of the inner cylindrical tube 330, that is, the peripheral portion of the outflow port 332. ing.

FIG. 12 is an external perspective view of the cylindrical member in the present embodiment.

The cover 2 side of the columnar member 314 is configured by a cylindrical columnar body 339 as shown in FIG. The cylindrical member 314 has a conical shape on the inner cylinder tube 330 side of the cylindrical body 339 with the inner cylinder tube 330 side as an apex, and an arc blade 340 (corresponding to the cylindrical blade 17) is provided on the outer periphery of the conical shape. Four pieces are equally arranged in a circular shape.

Next, a foreign matter separation mechanism in the vent hood 300 will be described.

The outdoor air containing foreign matter flows into the vent hood 300 from the first air inlet 8, turns into a swirling airflow by the fixed vanes 11, and swirls in the first swirl chamber 15 toward the front side of the vent hood 300. To do. Here, the foreign matter moves to the space dividing plate 13 side by centrifugal force, and moves to the second swirl chamber 19 through the through hole 21. The air from which the foreign matter is separated flows into the inner tube 330 from the inner tube end 333 and flows out of the apparatus through the outlet 332. That is, the swirling airflow that has flowed in from the first air supply port 8 at the inner tube pipe front end port 333 has its traveling direction reversed. In addition, it can be said that the swirling airflow that flows in from the first air supply port 8 can reverse the traveling direction between the outside and the inside of the inner tube 330.

The foreign matter moved to the second swirl chamber 19 is temporarily stored in the second swirl chamber 19. Since the inside of the ventilation opening hood 300 has a negative pressure by the blower, air flows into the second swirl chamber 19 from the second air supply opening 10. The inflowing air passes through the through hole 21 and flows into the first swirl chamber 15 and merges with the swirling airflow in the first swirl chamber 15.

In addition, when natural wind blows on the outdoor side of the second air supply port 10, the static pressure decreases on the outdoor side of the second air supply port 10. When the static pressure on the outdoor side of the second air supply port 10 becomes lower than the static pressure on the second swirl chamber 19 side, the separated foreign matter is pulled out outdoors. As a result, the foreign matter is automatically discharged to the outside, so that the foreign matter does not continue to be stored in the second swirl chamber 19 and the maintenance for removing the stored matter can be made unnecessary.

FIG. 13 is a view for explaining the flow of the airflow when the axial sectional area of the inner tube does not change. The white arrow indicates the direction of airflow, and the black arrow indicates the airflow vector. The black line inside the black arrow is a line (stream line) indicating the flow direction of the airflow.

When the inner tube is in the shape of FIG. 13, when the blower is driven, the airflow outside the inner tube flows from the inner tube end 433 while changing the traveling direction, as indicated by the black arrows. At this time, a vortex as shown by a streamline is generated starting from the cylindrical wall end 434 of the inner tube pipe front end 433. This eddy current impedes the flow of the air flow, thereby increasing the pressure loss. That is, the vortex generated in the inner cylindrical tube has caused the pressure loss.

Therefore, the inner tube 330 shown in FIG. 11 of the present invention is provided with a wall surface slightly smaller along the outer surface of the vortex. As shown in FIG. 13, the position where the thickness of the eddy current becomes maximum is between the inner cylindrical tube front end 433 and the intermediate position of the entire length of the inner cylindrical tube 330. Therefore, the inner tube 330 of the present embodiment includes a minimum cross-sectional area portion corresponding to a portion where the thickness of the eddy current is maximum, that is, a portion having a minimum diameter φmin.

The minimum diameter φmin is provided between the inner tube pipe tip 333 and the intermediate position of the entire length of the inner tube 330. The minimum diameter φmin is preferably φmin = (0.77 to 0.87) × φin. In the present embodiment, φmin = 0.82 × φin.

When the minimum diameter φmin is smaller than 0.77 times the diameter φin, which is the diameter of the inner tube end 333, the air passage area is reduced, so that the ventilation resistance is increased and the pressure loss is increased. Also, if the minimum diameter φmin is larger than 0.87 times the diameter φin, which is the diameter of the inner tube end 333, the vortex generated from the cylindrical wall end 334 cannot be completely eliminated, and the pressure loss is sufficiently reduced. It cannot be reduced. By setting the minimum diameter φmin to 0.77 to 0.82 times the diameter φin, which is the diameter of the inner tube end 333, the inner peripheral surface 336 is provided slightly smaller along the outer surface of the vortex flow. Become. According to this configuration, due to the airflow attracting effect on the inner peripheral surface 336, the effective area in which the airflow flows in the original traveling direction can be expanded. As a result, the airflow resistance can be reduced and the pressure loss can be reduced.

After passing through the minimum cross-sectional area portion, in order to reduce the flow velocity, the cross-sectional area of the inner tube 330 is gradually increased so as not to disturb the air flow, and the diameter of the outlet 332 is increased to the same size as the outlet 332. Is the diameter φout.

Furthermore, as shown in FIG. 11, the cylindrical wall end 334 is provided with an R-shaped portion 335 that bulges outwardly from the inner tube 330. The inner peripheral surface 336 and the outer peripheral surface 341 of the inner tube 330 are continuously connected along an arc shape along the R-shaped portion 335. A groove 337 is provided on the surface of the maximum diameter portion 342 of the R-shaped portion 335 around the entire center axis 4. By forming the cylindrical wall end portion 334 as described above, the direction of the airflow is smoothly changed along the R-shaped portion 335 while suppressing the occurrence of the separation phenomenon of the airflow flowing through the outer peripheral surface 341 of the inner tube 330. Can be changed. Therefore, the inflow loss when flowing into the inner cylindrical tube 330 can be reduced, and the pressure loss can be reduced.

As described above, the width of the groove 337 provided in the R-shaped portion 335 is as narrow as 1/3 to 1/5 of the depth and does not affect the air flow, so that the pressure loss due to the groove 337 does not increase. .

The groove 337 is for preventing water droplets that have entered from the first air supply port 8 from flowing into the inner tube 330 through the outer peripheral surface 341 of the inner tube 330.

Thus, the shape of the inner tube 330 of the present invention has three effects. First, the inflow loss of the air flowing into the inner tube 330 can be reduced by the R-shaped portion 335 provided at the cylindrical wall end 334. Second, by reducing the cross-sectional area of the inner cylindrical tube 330, the influence of the vortex generated from the end of the inner cylindrical tube 330, that is, the cylindrical wall end 334 can be eliminated. Third, the cross-sectional area can then be gradually increased to reduce the flow velocity. These three effects can significantly reduce pressure loss. Further, by providing the groove 337 in the R-shaped portion 335, it is possible to prevent water droplets from entering without increasing the pressure loss.

In the prior art document (Japanese Patent Laid-Open No. 2000-128591), only the inflow loss is reduced, so that the effect of reducing the pressure loss is limited.

Further, by extending the cylindrical wall end portion 334 to a position overlapping the space dividing plate 13, water droplets that have entered from the first air supply port 8 directly enter the inner cylindrical tube 330 from the inner cylindrical tube distal end port 333. Can be prevented.

Further, since the structure of the inner tube 330 according to the present embodiment does not affect the separation of foreign matter, the pressure loss can be reduced while maintaining the separation performance.

The cylindrical member 14 can receive the swirling airflow with the arc blade 340 and collect it at the center. The root portion of the arc blade 340 has a conical shape with the inner tube 330 side as a vertex. According to this configuration, the airflow received by the arc blade 340 is gathered at the center and is directed toward the apex side, that is, the inner tube 330 side along the conical surface, so that air tends to flow smoothly downstream. Under the influence of this flow, the airflow flowing in the vicinity of the inner peripheral surface 336 of the inner tube 330, particularly the airflow flowing along the wall surface near the minimum diameter φmin, tends to flow smoothly downstream. That is, the cylindrical member 14 and the shape of the inner cylindrical tube 330 which is the shape of the present embodiment are combined to further reduce the pressure loss.

(Embodiment 5)
In the present embodiment, a configuration of a vent hood that is easy to assemble, prevents outside air from flowing into the separation chamber, and can suppress a decrease in separation performance will be described.

In addition, about the structure already demonstrated in description of Embodiment 1-4, in order to avoid duplication, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.

FIG. 14 is an external perspective view of the vent hood according to the fifth embodiment as viewed from the front side. In addition, FIG. 14 is the external appearance which looks when it looks down from the outdoor side upper direction, when it attaches to a house outer wall by the front side of the ventilation opening hood 500 similarly to FIG.

FIG. 15 is a cross-sectional view along the central axis of the vent hood according to the fifth embodiment. As shown in FIG. 15, an exhaust duct is connected to the connection pipe 531, and a blower is connected to the downstream side of the exhaust duct.

Next, the external configuration of the vent hood 500 will be described.

As shown in FIG. 14, the vent hood 500 of the present embodiment is attached to the outer wall surface of the house with the central axis 4 substantially horizontal. In the present embodiment, the left side in FIG. 15 is the top surface side of the ventilation hood 500 (the top surface 6 side of the cover 2), and the cover 2 is provided to cover. On the other hand, the right side in FIG. 15 is the bottom side of the vent hood 500 (the bottom side of the cover 2), and the base plate 3 is provided. The upper and lower portions of the cover 2 are each provided with a blank 9 for bending along the arc shape of the cover 2, thereby connecting the cover 2 and the base plate 3. The internal space that can be formed by connection is cylindrical.

The cover 2 and the base plate 3 are connected via a blind plate 9. As a result, a gap is provided between the cover 2 and the base plate 3 to form the first air supply port 8. The first air supply port 8 is configured to contact the base plate 3 on the side surface of the ventilation port hood 500 so that air can flow in approximately 360 degrees around the central axis 4. In addition, the blanking board 9 part is a shielding part, and air does not flow in.

The first air supply port 8 is provided with a plurality of fixed blades 11 that are plate-like members arranged obliquely toward the central axis 4 so that the inflowing air turns. In other words, the fixed blade 11 is provided at a predetermined angle in the same direction with respect to the tangent of the arc centered on the central axis 4 in a cross section orthogonal to the central axis 4.

As shown in FIG. 14, a second air inlet 10 is provided in a portion located at the lower part of the cover 2.

Next, the internal structure of the vent hood 500 will be described with reference to FIG.

The inside of the cover 2 is divided into a first swirl chamber 15 and a second swirl chamber 19 by a space dividing plate 13, and the second swirl chamber 19 has an annular shape and surrounds the first swirl chamber 15. A through hole 21 is provided in the space dividing plate 13, and the first swirl chamber 15 and the second swirl chamber 19 are spatially connected via the through hole 21.

In FIG. 15, the space dividing plate 13 is a cross-sectional area (center) of the first swirl chamber 15 from the end on the first air supply port 8 side, that is, the end on the fixed blade 11 side toward the top surface 6 side of the cover 2. It has a truncated cone shape that is inclined so that the surface perpendicular to the axis 4 becomes smaller. A space formed by disposing the space dividing plate 13 that is a truncated cone inside the cover 2 that is a cylinder is a second swirl chamber 19.

Further, as shown in FIG. 15, the base plate 3 is provided with a circular opening 532 in the center so as to be coaxial with the central axis 4. A cylindrical tube 5 is provided so as to penetrate through the opening 532. The inner side portion of the ventilation hood 500 of the cylindrical tube 5, that is, the inner cylindrical tube 530 is provided with a cylindrical wall end portion 534 through which air flows. Further, the outside of the ventilation hood 500 of the cylindrical tube 5 is a connection tube 531 to which a ventilation duct can be connected. The cylindrical wall end portion 534 extends in the direction of the central axis 4 to a position overlapping the space dividing plate 13 in FIG.

As shown in FIG. 14, the second air supply port 10 is an opening provided on the side surface of the cover 2 so that the central axis 4 is positioned at the lower part in the gravitational direction in a horizontal state. The second air supply port 10 is a rectangular opening that is long in the direction of the central axis 4 and spatially connects the second swirl chamber 19 and the outdoors.

As shown in FIG. 15, a lower shielding plate 545 and an upper shielding plate 546 are provided in the second swirl chamber 19. A plurality of lower shielding plates 545 are provided on the through hole 21 side in the vicinity of the second air inlet 10. The upper shielding plate 546 is provided so as to be positioned at the upper part in the gravity direction with the second air supply port 10 at the lowest position. The lower shielding plate 545 and the upper shielding plate 546 are provided in the second swirl chamber 19 radially about the central axis 4. The lower shielding plate 545 and the upper shielding plate 546 do not completely block the second swirl chamber 19 as a separation chamber, and a gap is formed between the lower shielding plate 545 and the upper shielding plate 546 and the cover 2. It is left and foreign objects and air can come and go. A plurality of lower shielding plates 545 are provided between the second air supply port 10 and the through hole 21. In the present embodiment, the space dividing plate 13, the plurality of fixed blades 11, the lower shielding plate 545, and the upper shielding plate 546 are integrated.

Next, the separation mechanism will be described.

The outdoor air containing foreign matter flows into the ventilation hood 500 from the first air supply port 8 and becomes a swirling airflow by the fixed blade 11. As a result, the outdoor air containing foreign matter swirls in the first swirl chamber 15 while heading toward the top side of the vent hood 500. Here, the foreign substance moves to the outer peripheral side of the first swirl chamber 15 by centrifugal force, that is, to the space dividing plate 13 side, and moves to the second swirl chamber 19 through the through hole 21 by centrifugal force. The air from which the foreign matter has been separated flows into the inner tube 530 and out of the apparatus through the connection tube 531.

The foreign matter moved to the second swirl chamber 19 is temporarily stored in the second swirl chamber 19. Since the ventilation port hood 500 has a negative pressure by the blower, air flows into the second swirl chamber 19 from the second air supply port 10. The air that flows into the second swirl chamber 19 from the outside tends to go to the through hole 21 provided in the space dividing plate 13, but is blocked by the lower shielding plate 545 and the upper shielding plate 546. Therefore, a small amount of air flows into the first swirl chamber 15 from the second air supply port 10 through the through hole 21. The slight air flows from the second swirl chamber 19 through the through hole 21 to the first swirl chamber 15, and merges with the swirl airflow in the first swirl chamber 15.

On the other hand, when natural wind blows on the outdoor side of the second air supply port 10, the static pressure on the outdoor side of the second air supply port 10 decreases. When the static pressure on the outdoor side of the second air supply port 10 becomes lower than the static pressure on the second swirl chamber 19 side, the separated foreign matter is pulled out outdoors. As a result, the foreign matter is automatically discharged to the outside, so that the foreign matter does not continue to be stored in the second swirl chamber 19 and the maintenance for removing the stored matter can be made unnecessary.

Next, features of the present embodiment will be described.

FIG. 16 is an enlarged view of a portion A in FIG. FIG. 16 is a view in which the space dividing plate 13 is to be fitted into the cover 2 to which the packing 547 is attached.

The space dividing plate 13 is provided with fixed blades 11, an upper shielding plate 546, and a lower shielding plate 545. If these are formed integrally, handling during assembly becomes easy. The space dividing plate 13 includes a flange portion 548 that protrudes toward the outer peripheral side on the base plate 3 side. The fixed blade 11 is erected from the flange portion 548 to the base plate 3 side. Furthermore, a ring-shaped contact rib 549 is provided at the outer peripheral end of the flange portion 548 so as to stand up toward the top surface side of the ventilation port hood 500.

The outer peripheral surface of the contact rib 549 is a contact surface 550 that comes into contact with a packing 547 described later. The contact surface 550 is a conical surface whose diameter decreases toward the top surface of the vent hood 500. The inclination direction of the contact surface 550 is the same as the inclination direction of the truncated conical space dividing plate 13.

15 and FIG. 16, a packing 547 is attached to the inside of the cover 2. The packing 547 has an inner diameter that is smaller than the outer diameter of the contact rib 549.

When assembling the vent hood 500 of the present embodiment, the space dividing plate 13 is inserted into the cover 2 and the upper and lower blind plates 9 and the base plate 3 are fixed.

Since the outer diameter of the contact rib 549 on the tip side (the top surface side of the vent hood 500) is slightly larger than the inner diameter of the attached packing 547 (it may be the same as or smaller than the inner diameter of the packing 547), the space When the dividing plate 13 is fixed to the cover 2, the space dividing plate 13 is easily fitted into the cover 2. When the space dividing plate 13 is further inserted, the contact rib 549 gradually crushes the packing 547 along the inclination of the contact surface 550. For this reason, the space dividing plate 13 can smoothly squeeze the packing 547 to keep the cover 2 firmly sealed.

Although not shown in the drawing, a wire net or the like may be provided in the first air supply port 8 in order to prevent large insects from entering from the first air supply port 8. That is, a cylindrical wire mesh may be provided so as to cover the first air supply port 8. The wire mesh provided in the first air supply port 8 has substantially the same diameter as the inner diameter of the cover 2, and the space dividing plate 13 may be inserted after the wire mesh is connected in advance to the cover 2 side. In this case, the packing 547 may be attached to the inner peripheral side of the cover 2. That is, when the packing 547 is attached to the space dividing plate 13 side, the packing 547 needs to have a thickness that makes the outer diameter of the packing 547 larger than the inner diameter of the cover 2. In this state, if the space dividing plate 13 is to be inserted into the cover 2, the packing 547 provided so as to swell toward the outer peripheral side is caught by the tip of the wire mesh, making assembly very difficult. Therefore, the packing 547 may be attached to the cover 2 side. When the packing 547 is attached to the cover 2 side, the abutment surface 550 is an inclined surface when the space dividing plate 13 is inserted, so that the packing 547 can be gradually crushed, which facilitates assembly. Become.

In this way, by sealing the space between the second swirl chamber 19 and the cover 2 with the packing 547, the communication portion between the second swirl chamber 19 and the outside can be limited to the portion of the second air inlet 10. . That is, the outside air directly flowing into the second swirl chamber 19 is only from the second air supply port 10, thereby increasing the flow from the second swirl chamber 19 to the first swirl chamber 15 through the through hole 21. Can be prevented. Therefore, the movement of the foreign matter from the first swirl chamber 15 to the second swirl chamber 19 can be prevented from being hindered, so that a decrease in separation performance can be suppressed. Moreover, since the outside air flowing in from the second air supply port 10 suppresses the flow toward the through hole 21 by the lower shielding plate 545 and the upper shielding plate 546, it does not affect the separation performance.

That is, since it is possible to suppress the outside air from flowing into the second swirl chamber 19 from the gap between the space dividing plate 13 and the cover 2, it is possible to suppress a decrease in separation performance. Since the contact surface 550 that contacts the packing 547 is a conical surface, the packing 547 can be gradually crushed during the assembly, so that the assembly is facilitated and the inclined contact surface 550 is inclined. Since the packing 547 is pressed down firmly, the sealing performance is also improved.

The cyclone separation device according to the present invention is configured to reduce the size of the device and reduce the size and to improve the design, while separating the foreign matter and returning it to the outdoors, and also preventing the entry of wind and rain. Therefore, it is useful as an outdoor hood or the like attached to the ventilation opening (supply side) of the building.

1,300,500 Ventilation hood 2 Cover 3 Base plate 4 Center shaft 5 Cylindrical tube 6 Top surface 7 Side surface 8 First air supply port 9 Blind plate 10 Second air supply port 11 Fixed vane 12 Upstream end portion 13 Space Dividing plate 14,314 Column member 15 First swirl chamber 16 Fixed plate 17 Cylindrical blade 18 End surface of cylindrical tube 19 Second swirl chamber 21 Through hole 22 First shielding member 23

Second shielding member

25, 125, 225 Water shielding member 226

Cutting Notch

103, 330, 530

Inner tube

331, 531 Connection tube 332

Outflow port

333, 433

Inner tube end

334, 434, 534 Cylindrical wall end 335 R-shaped portion 336 Inner peripheral surface 337 Groove 338 Flange 339 Cylinder 340 Arc blade 341 Outer peripheral surface 342 Maximum diameter portion 545 Lower shielding plate 546 Upper shielding plate 547 Packing 548 flange portion 549 contacts the rib 550 abutting surface

Claims

A cover having a rotating body shape in which airflow flows in from the side surface and flows out from the bottom surface;
A cylindrical tube that includes the central axis of the cover and that is provided so as to pass through the bottom surface from the inside of the cover and make the inside of the cover negative pressure;
A space dividing plate for forming a space that becomes a first swirl chamber and a second swirl chamber on the outer peripheral side of the cylindrical tube and the inner peripheral side of the cover, respectively;
A cylindrical member provided to face the end surface of the cylindrical tube in the first swirl chamber, and the cover has a top surface facing the bottom surface portion, and a first surface on the bottom surface portion side of the side surface portion. An air supply port is provided, and a second air supply port is provided on the top surface side of the side surface portion,
The first air supply port is a plurality of openings formed by a plurality of fixed blades arranged so as to go around the side surface portion,
The second air supply port is an opening that is vertically long along the direction of the central axis in a state where the central axis is horizontally disposed, and can be positioned at the lowermost portion of the side surface portion,
The space dividing plate has a through hole that communicates the first swirl chamber and the second swirl chamber, and the position of the through hole is based on the second air supply port around the central axis. A vent hood in which the distance in the flow direction of the airflow swirling in the first swirl chamber is longer than the distance in the counterflow direction.
The space dividing plate has a cylindrical shape or a truncated cone shape arranged on the top surface side of the first air supply port in the central axis direction, and an inner periphery of the space dividing plate in the central axis direction. The ventilating hood according to claim 1, wherein an end surface of the cylindrical tube extends on a side.
In the second swirl chamber, a first shielding member is provided on the space dividing plate so as to stand upright so as to block a part of the flow path of the air flow in the second swirl chamber,
The said 1st shielding member is provided in the said through-hole side from the line | wire which connected the said center axis | shaft and the said 2nd air supply port, It extended to the outer peripheral side of the said space division board from the said center axis | shaft side. Ventilation hood as described.
In the second swirl chamber, a second shielding member is provided on the space dividing plate so as to block a part of the flow path of the airflow in the second swirl chamber, and the second shielding member is 4. The ventilation port according to claim 2, wherein when the second air supply port is positioned at a lowermost part, the ventilation port is provided above the central axis and extends from the central axis side to the outer peripheral side of the space dividing plate. hood.
In the state where the second air supply port is located at the lowermost portion of the side surface portion,
The ventilating hood according to claim 1, wherein a blind plate is disposed between one opening and the other opening of the first air supply opening at an upper part and a lower part of the cover.
2. The ventilation port according to claim 1, wherein in the first swirl chamber, the columnar member is erected from a wall surface on the top surface side, and a ring-shaped water-impervious member surrounding the outer periphery of the columnar member is provided on the wall surface. hood.
The ventilation opening hood according to claim 6, wherein the water shielding member is provided with an inclination on a side surface on the cylindrical member side so that water flows from the inside to the outside of the water shielding member.
The ventilation hood according to claim 6 or 7, wherein the water shielding member is provided with a notch at a lowermost position in a state where the central axis is horizontally arranged.
The cylindrical tube includes an inner tube extending from the outlet provided in the bottom surface portion into the first swirl chamber, and a cylindrical wall end that forms an inner tube tube distal end that is a tip of the inner tube The portion has a flow path that reverses the traveling direction of the swirling airflow flowing in from the first air supply port between the outside and the inside of the inner tube,
The cross-sectional area in a plane perpendicular to the central axis of the inner tube is changing in the central axis direction,
The cross-sectional area is minimized on the cylindrical wall end side with respect to the intermediate position of the entire length of the inner cylindrical tube, and from the position of the minimum cross-sectional area of the inner cylindrical tube toward the cylindrical wall end side. The vent hood according to claim 1, wherein the hood is gradually enlarged.
The cylindrical wall end portion is provided with an R-shaped portion that bulges out toward the outside of the inner tube, and the inner and outer peripheral surfaces of the inner tube are continuously along the R-shaped portion. The ventilation opening hood of Claim 9 connected with the circular arc.
The cylindrical wall end portion is provided with an R-shaped portion that bulges out toward the outside of the inner cylindrical tube, and a groove is formed on the outer peripheral surface of the inner cylindrical tube on the surface of the R-shaped portion over the entire circumference. The ventilation opening hood of Claim 9 formed.
When the diameter of the front end of the inner tube is φin, the diameter of the minimum cross-sectional area of the inner tube is φmin, and the diameter of the end on the outlet side of the inner tube is φout, φin> φout> φmin The ventilating hood according to claim 9, which is related and φmin = (0.75 to 0.85) × φin.
A cover having a rotating body shape in which airflow flows in from the side surface and flows out from the bottom surface;
A base plate that closes the bottom surface and is provided with an opening that is an outlet of the airflow at the center;
A space dividing plate for dividing the inside of the cover into a first swirl chamber on the inner peripheral side and a second swirl chamber on the outer peripheral side;
A cylindrical tube penetrating the base plate and provided to communicate with the first swirl chamber and the outside,
The cover has a top surface facing the bottom surface portion, and a first air supply port having a structure capable of generating a swirling airflow in the first swirl chamber is provided on the bottom surface portion side of the side surface portion,
A second air supply port that communicates the second swirl chamber and the outside is provided on the top surface side of the side surface portion;
The first air supply port is connected to the bottom surface side of the cover,
The cylindrical tube extends from the base plate into the first swirl chamber, and has a front end opening of the inner tube that allows air to flow into the first swirl chamber side, and an outlet through which the air flows out to the bottom surface side. Have
The space dividing plate has a through hole for communicating the first swirl chamber and the second swirl chamber, and a ring-shaped contact surface on an outer peripheral portion on the bottom surface portion side,
The contact surface is a conical surface whose diameter decreases toward the top surface, and the contact surface and the inner peripheral surface of the cover are in close contact with each other through packing.
The packing is affixed to the inner surface of the cover,
On the bottom surface portion side of the space dividing plate, a flange portion protruding to the outer peripheral side is provided,
In the first air supply port, a plurality of fixed blades are erected on the bottom surface portion side of the flange portion, and the fixed blades are integrated with the space dividing plate,
The ventilation port hood according to claim 13, wherein a contact rib projecting toward the top surface is provided at an outer peripheral end of the flange portion, and the outer peripheral surface of the contact rib is the contact surface.
The ventilating hood according to claim 14, wherein the space dividing plate has a truncated cone shape whose diameter decreases toward the top surface side so as to be in the same inclination direction as the contact surface.