JPH0893695A - Fan casing - Google Patents

Abstract

PURPOSE: To ensure high static pressure of blowout air flow and restrain noises by preventing the counter-flow of air in a blowout port. CONSTITUTION: A rib 21H for shielding a portion of a blowout port 21C is provided. The rib 21H is continued to a tongue part 21F along the outer peripheral shape of an impeller 22 received in a swirl chamber 21A. In a preferred embodiment, as the rib 21H separates from the tongue part 21F along the outer peripheral shape, the opening area of the blowout port 21C is gradually increased. Thus, even if some blowout air near the tongue part 21F tends to flow backward, the air flow flowing backward is interrupted by the rib 21H, so that the counterflow of the blown out air can be surely blocked. Thus, the reduction of the static pressure caused by the counterflow of blowout air flow and the generation of abnormal noises can be surely blocked.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fan casing, and more particularly to a fan casing suitable for a sirocco fan incorporated in an air conditioner.

[0002]

2. Description of the Related Art Generally, a fan casing of a blower is
As shown in FIG. 5B, the spiral chamber 2 that houses the impeller 1
And an air inlet 3 for introducing outside air into the swirl chamber 2,
An outlet 4 is provided for blowing the introduced air from the swirl chamber 2. The outlet 4 is partitioned by a wall surface 5 that is continuous with the swirl chamber 2 and a tongue portion 6.

This type of blower is built in an air conditioner such as a heat exchange ventilator and allows air to flow through a predetermined ventilation resistance (for example, a heat exchange element or a filter). At this time, in the blower type blower that blows air to the ventilation resistance, the air outlet 4 is made to face the ventilation resistance, and the pressurized air to which the centrifugal force is applied by the impeller 1 is pressure-fed to the ventilation resistance. ing.

[0004]

The blower described above is preferably one having a high static pressure of the blowout flow and a low noise level in order to uniformly blow air to the ventilation resistance. However, when a blower such as that described above is used in a small air conditioner, it becomes impossible to secure a sufficient distance from the outlet of the fan casing to the ventilation resistance, and if the static pressure of the blowout flow is increased, the air will There was the problem of backflow near the tongue. When such a backflow occurs, there has been a problem that the static pressure of the blowout flow is reduced, and moreover, abnormal noise is generated at the blowout port.

The present invention has been made in view of the above problems, and it is possible to prevent the backflow of air at the air outlet, thereby ensuring a high static pressure of the air outlet and suppressing noise. The purpose is to provide a casing.

[0006]

In order to solve the above-mentioned problems, the structure according to claim 1 of the present invention is a fan provided with a swirl chamber for accommodating an impeller and a tongue portion for defining an outlet of the swirl chamber. A fan casing, characterized in that the casing is provided with a rib that blocks a part of the air outlet by continuing with the tongue along the outer peripheral shape of the impeller housed in the spiral chamber.

According to a second aspect of the present invention, in the fan casing according to the first aspect, the rib gradually increases the opening area of the air outlet as the rib moves away from the tongue along the outer peripheral shape. It is a thing.

[0008]

In the structure according to the first aspect of the invention, as the impeller rotates in the spiral chamber, the air pressurized in the spiral chamber is blown out from the air outlet. Here, since the rib that is continuous with the tongue that defines the air outlet extends in the direction along the outer peripheral shape of the impeller and shields part of the air outlet, the vicinity of the tongue in the blown air Even if an object tries to backflow, the airflow in the backflow direction is blocked by the ribs.

Further, in the structure of claim 2, the rib is
Since the opening area of the air outlet is gradually increased as it moves away from the tongue along the outer peripheral shape, the main flow of air blown out is blown out from the air outlet without being blocked by the ribs, but the reverse flow is In the vicinity of the tongue portion where it is likely to occur, the rib surely blocks the flow of air in the reverse flow direction.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings. FIG. 1 is an exploded perspective view showing a blower adopting a fan casing according to an embodiment of the present invention with a part thereof broken away, and FIG. 2 is a heat exchange as an air conditioner adopting the blower of FIG. FIG. 3 is a perspective view showing a schematic configuration of a ventilation device, FIG. 3 is a schematic bottom view of the heat exchange ventilation device of FIG. 2, and FIG. 4 is a graph showing air volume-static pressure characteristics and air volume-sound pressure level characteristics at an outlet. 5 is a graph showing FIG.
Shows a schematic configuration of a fan casing measured in the graph of FIG. 4, (A) is a schematic sectional view of the present embodiment, and (B) is a schematic sectional view of a conventional example.

First, referring to FIGS. 2 and 3, the heat exchange ventilator according to the present embodiment is provided with a box-shaped casing 10 which is embedded in the ceiling. Blower 20 for circulating air, and blower 20
And a heat exchange element 30 for exchanging heat between the air blown by the air. The casing 10 is
The one side wall is provided with an outdoor air introduction port OA for introducing the outdoor air into the inside and an exhaust port EA for discharging the indoor air to the outside. Further, a decorative panel 11 is attached to a lower portion of the casing 10, and the decorative panel 11 supplies a supply port SA for supplying the outdoor air introduced from the outdoor air introduction port OA to the room and an indoor air. An indoor air introduction port RA for introducing the air inside and discharging it from the exhaust port EA is partitioned. Then, in the casing 10, an air supply path SP for supplying the outdoor air introduced from the outdoor air introduction port OA to the supply port SA and the indoor air introduced from the indoor air introduction port RA are discharged. An exhaust path EP for discharging from the EA is partitioned inside.

The blower 20 has a fan casing 21.
The fan casing 21 partitions each of the air supply passage SP and the exhaust passage EP of the casing 10. Also, the blower 20 is
A pair of impellers 22 mounted on the fan casing 21
And an attachment plate 23 for attaching the impeller 22 to the fan casing 21, and the impeller 22 pumps air flowing through the paths SP and EP.

Referring to FIGS. 1 and 3, fan casing 21 is a foamed resin molded body molded by a well-known bead molding method, and has a pair of spiral chambers 21A provided for each impeller 22, 22. Is equipped with. Each swirl chamber 21A has an air introduction port 21B for introducing air into the swirl chamber 21A.
And a blowout port 21C that blows out the introduced air from the swirl chamber 21A. In this embodiment, the swirl chamber 21A of the fan casing 21 is partitioned so that the impeller 22 whose rotation center extends vertically can be introduced from the bottom when the fan chamber 21 is mounted on the heat exchange ventilation device. The air inlet 21B is formed in the upper part of the fan casing 21 and opens in the substantially central portion of the spiral chamber 21A. Although not specifically shown, this air inlet 2
A bell mouth is fitted into 1B, and air is introduced from the bell mouth into the swirl chamber 21A. In order to connect the bellmouth for air supply and the outdoor air introduction port OA, the fan casing 21 has a cutout 21D.
Is formed, and a notch 21K and a step S are formed in the fan casing 21 to connect the exhaust bellmouth and the indoor air introduction port RA (see FIG. 1). Further, the blowout port 21C is formed on a side portion of the fan casing 21 so that the air pressurized in the swirl chamber 21A is pumped in a tangential direction A1 of the swirl chamber 21A substantially orthogonal to the side portion. There is.

As shown in FIG. 3, the outlet 21C is
A wall surface 21E that extends in the tangential direction A1 and is continuous with the spiral chamber 21A, and is partitioned by a tongue portion 21F. In the tongue portion 21F, the tip end portion 21G in bottom view is slightly inward of the spiral chamber 21A (the impeller 2 housed in the spiral chamber 21A).
2 toward the center). Further, in this embodiment, the rib 21H continuous with the tongue portion 21F is integrally formed.

As shown in FIG. 1, the rib 21H has an upper wall portion 2 which divides the swirl chamber 21A and the air introduction port 21B.
It rises from the lower surface of 1J and extends along the outer circumference of the impeller 22 housed in the spiral chamber 21A. The rib 21H slightly blocks the upper portion of the air outlet 21C, that is, the side on which the air inlet 21B is defined. Further, the rib 21H of the present embodiment has one end side which is continuous with the tongue portion 21F and the other end side which is interrupted at an intermediate portion of the blowout port 21C (see FIG. 3). Then, as shown in FIG. 1, the protruding height from the upper wall portion 21J increases toward the end portion on the tongue portion 21F side. In other words, the rib 21H of the present embodiment gradually increases the opening area of the outlet 21C as the rib 21H moves away from the tongue 21F along the outer peripheral shape of the impeller 22. Figure 5
Referring to (A), the maximum protrusion height h of the rib 21H
Is preferably 0.1 to 0.4 times the axial dimension H of the impeller 22. In this embodiment, a backflow prevention function,
It is set to 0.15 times, which is most compatible with the blowing performance.

Next, referring to FIG. 1, the impeller 22 will be described.
Is a rotary shaft 24 of a motor 24 fixed to a mounting plate 23.
An end plate 22A fixed to A, an end ring 22B facing the end plate 22A, and a large number of blades 22C arranged between the end plate 22A and the end ring 22B are integrally provided, As described above, the impeller 22 is introduced into the spiral chamber 22A from the end ring 22B side with the center of rotation being along the vertical direction. Therefore, in this embodiment, the rib 2
1H faces the end ring 22B (see FIG. 5A).

The mounting plate 23 is used for the fan casing 2
The bottom surface of the fan casing 21 is fixed to the lower surface of the fan casing 21 with screws (not shown).
Next, referring to FIGS. 2 and 3, the heat exchange element 30 includes an element body 31 and an element body 31.
And a pair of filters 33 detachably attached to the holding frame 32.

The element body 31 is formed by stacking a large number of unit members made of a material such as paper so that the air supply side flow passage communicating with the air supply passage SP and the exhaust side flow passage communicating with the exhaust passage EP. And are divided so that the heat of the air passing through both flow passages is exchanged. In the present embodiment, the heat exchange element 30 is arranged such that the stacking direction L of the unit members is horizontal along the direction in which the impellers 22, 22 of the blower 20 are continuously arranged. Each flow passage is formed along the direction orthogonal to the stacking direction L.

In this embodiment, the impellers 22 and 22 corresponding to the respective upstream sides of the air supply path SP and the exhaust path EP are provided.
And the flow passages of the heat exchange element 30 are set on the downstream side of the impellers 22, 22. The air supply side outlet 21C of each blower 20 communicates with the air supply side flow passage of the heat exchange element 30 through a static pressure chamber 40 for making the blowout flow a static pressure and at the exhaust side. The air outlet 21C is close to the exhaust side flow passage of the heat exchange element 30 due to the demand for downsizing.

According to the above structure, each impeller 22 is driven by the corresponding motor 24, and the spiral chamber 21A is driven.
By rotating inside, the outdoor air introduced from the outdoor air introduction port OA is pumped into the static pressure chamber 40 by the impeller 22 on the air supply side, and further passes through the heat exchange element 30 to supply air. While being supplied to the room through the port SA, the air in the room is introduced into the casing 10 through the outdoor air introduction port RA, and is pressure-fed to the heat exchange element 30 by the impeller 22 on the exhaust side, and then from the exhaust port EA. It is discharged outdoors.

In the above-mentioned process, as each impeller 22 rotates in the corresponding spiral chamber 21A, the air introduced from the air inlet 21B is pressurized in the spiral chamber 21A and blown out from the outlet 21C. To be done. Here, the rib 21H that is continuous with the tongue portion 21F that defines the outlet 21C is
The outlet 21 extends in a direction along the outer peripheral shape of the impeller 22.
Since a part of C is shielded, even if one of the blown air near the tongue portion 21F attempts to flow backward, the air flow in the reverse flow direction is blocked by the rib 21H.

Explaining in more detail, the air outlet 2 on the air supply side
1C pumps air to the heat exchange element 30 through the static pressure chamber 40 and is close to the static pressure chamber 40, so that when the static pressure of air in the static pressure chamber 40 increases, the tongue portion Backflow of air is more likely to occur on the 21F side. Also,
The air outlet 21C on the exhaust side is arranged close to the filter 33 of the heat exchange element 30, so that the tongue portion 2 is caused by the air flow resistance of the heat exchange element 30 which becomes ventilation resistance.
Backflow of air is more likely to occur on the 1F side. However, in the present embodiment, by providing the ribs 21H, even if one of the blown air near the tongue portion 21F tries to flow backward, the air flow in the reverse flow direction is blocked by the ribs 21H. It is possible to reliably prevent the backflow of the blown air. Therefore, it is possible to reliably prevent the generation of abnormal noise due to the reverse flow of the blowout flow and the decrease in static pressure, and to realize uniform air blowing to the heat exchange element 30.

Moreover, in the structure of this embodiment, the rib 21H
However, since the opening area of the blowout port 21C is gradually increased from the tongue portion 21F toward the wall surface, the main flow of blown air is blown out from the blowout port 21C without being blocked by the ribs 21H, but a reverse flow occurs. Easy to get tongue 21F, 21
In the vicinity of F, the rib 21H reliably blocks the flow of air in the reverse flow direction. Therefore, there is an advantage that it is possible to achieve both the backflow prevention and the suppression of the reduction of the blown air volume.

As shown in FIG. 5 (A), in the present embodiment, the rib 21H can effectively prevent the backflow of air. Therefore, as shown in FIG. 4, the static pressure is high with respect to the air volume. Moreover, the sound pressure level is lowered. On the other hand, since the conventional product cannot prevent backflow (see FIG. 5B), the static pressure is low and the sound pressure level is high as shown in FIG. .

As described above, according to this embodiment, the outlet 2
There is a remarkable effect that the backflow of air at 1C can be prevented, the static pressure of the blower 20 can be kept high, and the noise can be suppressed. The above-described embodiments are merely examples of preferred embodiments of the present invention, and the present invention is not limited to the above-mentioned embodiments. It goes without saying that various design changes can be made without changing the gist of the present invention.

[0026]

As described above, according to the first aspect of the present invention.
In the configuration described, even if one of the blown air near the tongue portion tries to flow backward, the flow of the air in the reverse flow direction is blocked by the ribs, so it is possible to reliably prevent the flow back of the blown air. You can Therefore, there is an advantage that it is possible to reliably prevent the generation of abnormal noise due to the reverse flow of the blowout flow and the decrease in static pressure.

According to the second aspect of the present invention, the main flow of the blown air is blown out from the blowout port without being blocked by the ribs, but the ribs surely flow backward in the vicinity of the tongue where backflow easily occurs. Since the flow of the air in the directional direction is blocked, there is an advantage that it is possible to achieve both the backflow prevention and the suppression of the decrease in the air flow rate. Therefore, according to the present invention, it is possible to prevent the backflow of air at the air outlet, thereby ensuring a high static pressure of the air outlet and suppressing noise.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a blower adopting a fan casing according to an embodiment of the present invention with a part thereof cut away.

FIG. 2 is a perspective view showing a schematic configuration of a heat exchange ventilator as an air conditioner, which employs the blower of FIG.

3 is a bottom schematic view of the heat exchange ventilator of FIG.

FIG. 4 is a graph showing air volume-static pressure characteristics and air volume-sound pressure level characteristics at an outlet.

5 shows a schematic configuration of a fan casing measured in the graph of FIG. 4, (A) is a schematic sectional view of the present embodiment, and (B) is a schematic sectional view of a conventional example.

[Explanation of symbols]

 20 Blower 21 Fan casing 21A Swirl chamber 21C Air outlet 21F Tongue 21H Rib 22 Impeller

Claims (2)

[Claims] Claim: What is claimed is: 1. A swirl chamber (21A), comprising: a swirl chamber (21A) accommodating an impeller (22); and a tongue portion (21F) defining a blowout port (21C) of the swirl chamber (21A). By continuing to the tongue (21F) along the outer peripheral shape of the impeller (22) housed in the blower outlet (21C)
A fan casing having a rib (21H) for shielding a part of the fan casing. 2. The fan casing according to claim 1, wherein the rib (21H) gradually increases the opening area of the air outlet (21C) as the rib (21H) moves away from the tongue (21F) along the outer peripheral shape. There is something.