JPH0610892A - Axial flow blower and air conditioner using this blower - Google Patents

Abstract

PURPOSE:To attain good assembly workability, miniaturization and power saving by achieving reduction of noise due to a vortex, generated between a mouth ring and blades of an axial fan, and a high air pressure CONSTITUTION:Disk-shaped mouth rings 4, 5 for partitioning suction and delivery sides are vertically fixed further with a distance D spaced, to an internal surface of a cylindrical case 3, to hollow most of a delivery side surface of the mouth ring in the downstream to a vertical or suction side, and an axial fan 1 is mounted on the inside of the mouth rings 4, 5. Throttle riseup parts 4a, 5a parallelly folded to the internal surface of the case 3 are provided in internal peripheral sides of the mouth rings 4, 5, and a space in point ends of these throttle riseup parts 4a, 5a serves as an opening part 8 of a bag-shaped space part 6 interposed by the mouth rings 4, 5. A vortex 7, generated in the periphery of a blade 1a by rotating the axial fan 1, is sucked into the bag- shaped space part 6 from the opening part 8, to eliminate a reverse flow toward the blade from the delivery side surface, and a noise due to this reverse flow is reduced to increase an air amount.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an axial flow type blower provided with a mouth ring for partitioning a suction side and a discharge side and an air conditioner using the same.

[0002]

2. Description of the Related Art As an axial flow type blower used for a conventional industrial blower, a ventilation fan, an air conditioner, etc., a suction side and a discharge side are separated from the axial flow fan, and the suction side to the discharge side are divided. It is known that a mouth ring is provided in order to facilitate the circulation of air. This will be described with reference to FIGS. 14 and 15. A mouth ring 62 is attached to the case so as to surround the axial fan 60 with a limited width, and the right side in the drawing is the suction side and the left side is the discharge side. On the side,
In this way, the suction side and the discharge side are clearly divided by the mouth ring 62. When the axial fan 60 rotates and air is sucked in from the suction side, the mouth ring 62
Negative pressure is generated in the suction side portion of the case, whereby the suctioned air near the inner surface of the case is smoothly guided to the central portion of the case and is sent to the discharge side through the axial fan 60. .

[0003]

However, in such an axial flow type blower, due to the rotation of the axial flow fan 60 housed in the case, a vortex is generated between the axial flow fan 60 and the tip of the blade. However, there is a problem that this causes noise. This will be described with reference to FIGS. 14 and 15.

FIG. 14 shows the state of the flow by the axial fan 60 when the load is small (the ventilation resistance is small). As a whole, this flow is in the form of a contracted flow up to the discharge end. Becomes In this case, unlike the mere suction action, the vortex 61 is added to the tip of the blade 60a as it approaches the trailing edge 60aa.
Occurs and grows gradually from upstream to downstream,
Since the gap between the mouth ring 62 and the blade 60a is narrow, the vortex noise increases, and the vortex 61 is forced to enter the blade 60a side, which interferes with the action of the blade 60a and raises the noise level. . At the same time, there is also a problem that the effective diameter Da4 of the fan that actually blows air becomes smaller, which lowers the air pressure and lowers the air flow rate.

When the load is large (the ventilation resistance is large)
As shown in FIG. 15, the downstream position (mouse ring 6
At the outlet end of 2), the discharge flow becomes an expanded flow that is directed in the centrifugal direction, so that the vortex 61 is moved closer to the center side of the width W of the mouth ring 62 and becomes a large vortex 61, which is the same as when the load is small. Since the gap between the blade and the blade 60a is narrow, the vortex noise rises, and the vortex 61 is forced to enter the blade 60a side, which interferes with the action of the blade 60a and raises the noise level. At the same time, there has been a problem that the effective diameter Da5 of the fan that actually blows air becomes smaller, which lowers the air pressure and reduces the amount of air blown.

An example of a method for eliminating the vortex generated at the tip of the blade of such an axial flow fan is disclosed in, for example, JP-A-61-1.
It is disclosed in Japanese Patent Publication No. 49600 and Japanese Utility Model Publication No. 63-193792. The former expands the space between the axial fan and the case, encloses the axial fan in the meantime, and has a large cross-sectional funnel-shaped throttle surface so that the narrow opening faces the axial fan side. A partition plate is provided so that the vortex generated at the tip of the blade of the axial fan enters the space formed by the partition plate through the opening of this partition plate. A ring is provided. However, when such a method is applied to the axial flow type blower provided with the mouth ring shown in FIGS. 14 and 15, the axial flow fan must be downsized by the amount of the partition plate and the sound deadening ring attached. Or, if the dimensions of the case and axial fan are not changed, not only will the vortex enter the blades because the partition plates are close, but also a backflow from the funnel-shaped throttle surface on the discharge side to the blades will occur. Therefore, there was a problem that the noise was increased and the air volume was decreased. Moreover, it is difficult to perform sheet metal drawing with a wide funnel-shaped drawing.

Further, in Japanese Patent Laid-Open No. 1-131835, a mouth ring on a plate is provided on the outer circumference of a propeller fan to bend the air flow in the direction of the propeller of the fan. In order to eliminate this, a guide piece is provided in this portion so that the air can smoothly flow by this guide piece. But,
This does not eliminate the vortex generated at the tip of the propeller, and even if it is applied to the axial flow type blower shown in FIGS. 14 and 15, the noise due to the vortex cannot be killed.

As a method for preventing a decrease in wind pressure and a stall, there is a method described in Japanese Utility Model Publication No. 3-29593. This is to arrange a ring-shaped ring with a specified cross-sectional shape without a pressure partitioning action in front of the suction side of the fan mouth ring. There is a problem that the noise is increased by inhibiting the noise, increasing the turbulence, decreasing the wind pressure, and increasing the noise. There is also a problem that the air flow is obstructed by the support member of the ring.

In the conventional axial flow type blower shown in FIGS. 14 and 15, the width W of the cylindrical portion of the mouth ring 62 has an optimum dimension depending on the load or the thickness B of the impeller. In such a case, there is a problem that changing the width W of the cylindrical portion involves changing the manufacturing mold.

Furthermore, when such an axial flow type blower is used in an air conditioner or the like, most of the case has a rectangular cross section, so that the outer shape of the mouth ring 39 must be rectangular according to the case. However, in such a case, it is very difficult to manufacture a cylindrical mouth ring having a wide width W by deep drawing by pressing from an iron plate, and even when this is resin-molded, a molding die is used. In addition to being able to be divided in the axial direction as well as in the radial direction, there is a problem that the molding die becomes complicated and expensive. Further, even if the outer shape is made circular by using a roller diaphragm, in this case, it is necessary to add a rectangular plate to the outside or attach it to the front case in the axial direction, and the conventional width W in the axial direction is wide. Mouth ring 62
There was a problem in that it was difficult to insert the bar of the spot welding machine or the front case of the driver into the narrow case in order to mount it in a narrow case.

The object of the present invention is to solve the above problems, to improve the mouth ring without increasing the size of the case or downsizing the fan, and to realize the reduction of blowing noise and the increase of wind pressure. Another object of the present invention is to provide a low-noise, high-wind pressure air conditioner using the axial flow type blower.

Another object of the present invention is to provide an axial-flow type blower having a mouth ring having a simple structure and easy to manufacture, and a compact, low-noise, power-saving type air conditioner using the same. Especially.

[0013]

In order to achieve the above object, according to the present invention, a mouth ring is arranged side by side at a predetermined distance in a direction perpendicular to an inner surface of a case and parallel to an axis of an axial fan. The first and second mouth rings are formed, and the position of the discharge side face is vertical to the case or indented in the suction direction except for the squeezing rising part at the inner end of the second mouth ring located downstream. A bag-shaped space having an opening facing the blade of the axial fan is formed between the first and second mouth rings.

Further, according to the present invention, the end portions of the first and second mouth rings on the axial fan side are bent to form a throttle rising portion parallel to the tips of the blades of the axial fan.

[0015]

By providing the bag-shaped space portion facing the outer circumference of the blade of the axial fan with the first and second mouth rings,
The vortex generated at the tip of this blade is sucked into this bag-shaped space without restraining its movement, which makes the movement of the vortex itself smooth and, moreover, from the blade of the axial fan. The growth of eddies downstream is also suppressed by going away,
Interference with the blade of the axial fan is reduced. At the same time,
The effective diameter of the fan that actually blows air becomes large, and low noise and high air pressure are achieved.

By providing a narrowing rising portion at the ends of the first and second mouth rings on the side of the axial fan, the bag-shaped space portion is in a partially closed state, and sucked vortices cause the bag-shaped space. It becomes difficult to get out of the part. For this reason, the noise and the wind pressure are further reduced. Also, the second
Since most of the discharge side of the mouth ring is dented in the case vertically or in the suction direction, there is no backflow from the discharge side, and low noise and high wind pressure can be achieved.

Further, since the mouth ring can be composed of two pieces, the throttle rising portion formed at the end portion on the axial flow type fan side may be short.
The mouth ring can be easily manufactured by shallow drawing. Furthermore, it becomes easy to adjust the distance between these mouth rings according to the load and the thickness of the impeller. Furthermore,
Since a narrow air conditioner can be mounted in the case one by one, the work for mounting the air conditioner in the case is facilitated.

[0018]

Embodiments of the present invention will now be described in detail with reference to the drawings. 1 to 3 show an embodiment of an axial-flow type blower according to the present invention. FIG. 1 is a longitudinal sectional view showing a state when a load is small, FIG. 2 is a front view thereof, and FIG. 3 is a load. FIG. 1 is a longitudinal sectional view of a large fan, where 1 is an axial fan, 1
a is its wing, 3 is a blower guide circular tube case, 4 and 5 are mouth rings, 4a and 5a are diaphragm rising portions, 6 is a bag-like space portion, 7 is a vortex, and 8 is an opening portion.

In FIGS. 1 and 2, two mouth rings 4 and 5 are attached to the inner surface of a cylindrical air guide case 3 having a cylindrical shape side by side in the central axis direction of the air guide circular tube case 3. Inside the mouth rings 4 and 5
Axial fan 1 coaxially with the inner surface of the circular tube case 3 for air guide
Are arranged. The axial fan 1 has, for example, four blades 1a and is rotated by a motor (not shown), whereby air flows in a direction indicated by an arrow X.

The mouth rings 4 and 5 are disc-shaped, and their inner diameter portions (the axial flow fan 1 side in the drawing) are bent to form throttle rising portions 4a and 5a, respectively. It is attached so as to be perpendicular to the inner surface of the case 3. That is, most of the surface except for the rising portion to be dictated is configured to be perpendicular to the case. The squeezing rising portions 4a and 5a of the mouth rings 4 and 5 are arranged so that their tips are opposed to each other with a predetermined interval, whereby a bag-shaped space portion 6 is formed between the mouth rings 4 and 5. At the same time, the gap between the tips of the squeezing rising portions 4a and 5a serves as the opening 8 of the bag-shaped space 6. The throttle R of the downstream-side throttle rising portion 5a is an axial fan 1
The outer diameter is less than 4%. The throttle rising portions 4a and 5a are parallel to the inner surface of the blower guide circular tube case 3, and the opening 8 is formed in a cylindrical surface formed by the tips of the blades 1a when the axial fan 1 rotates. They are positioned so as to face each other at a predetermined interval and to face a part of the cylindrical surface on the downstream side.

These mouth rings 4 and 5 are on the suction side (on the right side of the axial fan 1 in FIG. 1) on the outer periphery of the axial fan 1.
And the discharge side (on the left side of the axial fan 1 in FIG. 1). When the axial fan 1 rotates, the action of the mouth ring 4 causes the suction side outer periphery, that is, the mouth ring 4 shown in FIG.
On the upper right side, a negative pressure is generated near the inner surface of the blower guide circular tube case 3, so that, of the air sucked from the outside, the air passing near the inner surface of the blower guide circular tube case 3 is also drawn to the axial fan 1. As a result, the flow of air becomes smooth.

In such a structure, when the load is small, the entire flow of air due to the rotation of the axial fan 1 is as shown by the arrow X as in the conventional case, and the vortex 7 is formed at the tip of the blade 1a.
Occurs, but the bag-shaped space 6 between the mouth rings 4 and 5
Becomes negative pressure, so that the vortex 7 is sucked into the bag-shaped space portion 6 and moves away from the wing 1a, so that a natural body can be formed outward. In addition, most of the surface of the second mouth ring 5 located downstream is perpendicular to the case, and since the squeeze rising portion 5a is small, the angle formed between the discharge side surface and the discharge flow becomes steep, Backflow can be eliminated from the discharge side surface.

Therefore, the growth of the vortex 7 is suppressed and the vortex noise is reduced, and the vortex 7 is less likely to interfere with the rotation of the blade 1a, and the blade does not interfere with the backflow and the blade noise. Can also be reduced. Moreover, the effective diameter Da1 of the axial flow fan 1 that actually performs the blowing action becomes large, and a high wind pressure can be obtained.

When the load is large, as shown in FIG. 3, the discharge flow of the air that has passed through the axial fan 1 becomes an expanded flow that is directed in the centrifugal direction at the outlet side of the mouth ring 5 at the rear side, and therefore, the blades. The vortex 7 generated at the tip of the la is a mouth ring 4,
The space 5 is drawn toward the opening 8 side and sucked into the bag-shaped space 6. Moreover, since the bag-shaped space portion 6 is partially closed by the squeezing rising portions 4a and 5a, the vortex 7 that once entered is difficult to escape from the bag-shaped space portion 6.

Therefore, also in this case, the vortex 7 can be made a natural body outward away from the wing 1a, and the vortex 7 on the downstream side can be formed.
Is also suppressed and the vortex noise is reduced, and the vortex 7 less interferes with the blade 1a, so that the blade noise is also reduced.
In addition, it is not necessary to insert a new component, which requires a large space between the circular pipe case 3 and the axial fan 1, and it is possible to carry out with the dimensions of the conventional circular pipe and the dimensions of the axial fan. Instead, the effective diameter Da2 of the axial fan 1 that actually performs the blowing action becomes large, and a high wind pressure can be obtained.

Here, the dimension h of the squeezing rising portions 4a, 5a of the mouth rings 4, 5 may be small. Therefore, each of the mouth rings 4 and 5 can be easily manufactured from a single flat plate and extremely easily by drawing using the same die. In particular, the downsizing and rising portion 5a of the downstream second mouth ring 5 can be downsized to have the effect of preventing backflow.

Next, specific performance effects of this embodiment will be described. Here, the axial flow fan 1 has an outer diameter A = 4.
Using a propeller fan consisting of four blades of 00 mm and impeller thickness B = 110 mm, the inner diameter C of the mouth rings 4, 5
= 415 mm, dimension h of the rising portions 4a and 5a of h = 20
mm, these two identical mouth rings 4,
5 with a distance D = 70 mm, and a circular pipe case 3 for air guide
An axial flow type blower, which is attached to the air conditioner and has a bag-shaped space 8 having an opening 8 having a width of 30 mm, which is 585 min / min.
As a result of operating at the rotation speed, the maximum air volume is 29 m ³ / m
It was in.

Comparing this with the conventional axial flow type blower using a cylindrical mouth ring with a width W = 70 mm as shown in FIGS. 14 and 15, the load is relatively small and the air flow is 24 m.
The noise at the time of ³ / min was 39 dB in the conventional example, whereas it was 36 dB in this embodiment, which was 3 dB.
B decreased and the wind pressure (total pressure) was 18P compared to the conventional one.
However, in this example, the pressure was 20 Pa, which was 11% higher. Air volume with large load 12m ³ / mi
The noise at the time of n is 46 dB in the conventional case, but is 44.5 dB in this embodiment, which is 1.5 dB.
B decreased, and the wind pressure (total pressure) was 29 Pa in the conventional example, while it was 33 Pa in this example, which was 14%.
It became high. Further, the maximum efficiency of the fan was 57% (at 23 m ³ / min) in the conventional case, but was improved to 61% (at 24 m ³ / min) in this embodiment.
As described above, the effect of this example could be sufficiently confirmed.

Further, the throttle R of the downstream throttle riser 5a has a noise of 4% (R2) or less of the outer diameter of the axial flow fan when the air volume is 24 m ³ / min, as compared with the case without R.
It was found that the effect was only less than 0.3 dB increase, 1 dB increase at 5%, 1.5% increase at 6%, and the above-mentioned throttle R should be as small as 4% or less. I was able to confirm that I can reduce.

Next, another embodiment of the axial-flow type blower according to the present invention will be described with reference to the drawings showing the main part thereof. However,
In each drawing, the same reference numerals are given to the portions corresponding to FIGS.

The embodiment shown in FIG. 4 has a mouth ring 7, 8
The tips of the respective squeezing rising portions 8a and 9a are further bent toward the bag-shaped space portion 10. This allows the tips of the squeezing rising portions 8a and 9a to be added in addition to the effects described in FIGS. The bent portion smoothens the rotation of the vortex in the bag-shaped space portion 10, further improving noise reduction.

In the embodiment shown in FIG. 5, the mouth ring 12,
The mouth rings 12 and 13 are attached to the blower guide circular pipe case 3 so that the respective throttle rising portions 12a and 13a face the discharge side in the same direction. It becomes the bag-shaped space portion 14. As a result, in addition to the effects described with reference to FIGS. 1 to 3, the discharge side surface of the second mouth ring 13 located downstream is configured to be dented from the tip of the throttle rising portion 9a toward the suction side. Since it is possible to efficiently eliminate the backward flow that is directed, it is possible to not only enhance the effect of reducing noise, but also obtain the effect of the air volume because the rising portion 9a is directed downstream. Further, the mouth rings 12 and 13 can be manufactured in the same mold, and the mounting work of the mouth rings 12 and 13 can be carried out in the same procedure, which is simple.

The embodiment shown in FIG. 6 is one in which one mouth ring 16 is attached in the middle of the other mouth ring 17 in the radial direction, that is, on the vertical surface 17b to form a bag-shaped space portion 18. In addition to the effect described in 5, the two mouth rings 16 and 17 can be assembled as a set before being attached to the air guide circular tube case 3, and the mouth ring 1
A space 20 between the blower guide circular tube case 3 and the blower guide circular tube case 3 can be utilized as a storage portion for other components such as a heat exchanger and electric parts.
Here, the squeezing rising portions of the mouth rings 12 and 13 are oriented in the same direction, but as shown in FIG. 1, the tips may be opposed to each other, or the shape as shown in FIG. May be

In the embodiment shown in FIG. 7, the mouth ring 2 is used.
The riser portions 21a and 22a of the diaphragms 1 and 22 are respectively flat portions 21b and 22 which are perpendicular to the blower guide circular pipe case 3.
It is assumed that it is bent from b with a large radius of curvature, and these flat portions 21b and 22b are fixed back to back. A bag-shaped space 23 is formed by the inclined outer surfaces of the diaphragm rising portions 21a and 22a.

With this structure, in addition to the effect described with reference to FIG. 6, a new circular tube case is unnecessary, and the bag-shaped space 23
Is composed of a slope, the vortex can be smoothly rotated by using the slope, which further improves noise reduction. Moreover, in terms of production, the two mouth rings 21 and 22 can be assembled as a set and the two can be closely attached to each other, so that the positioning thereof is easy. Further, the squeezing rising portion 21 is larger than the embodiment shown in FIG.
Since the space 24 outside the a and 22a can also be widened, this can be utilized as a storage place for other parts, and the small size of the air conditioner or the like using this embodiment is promoted.

In the embodiment shown in FIG. 8, the mouth ring 25,
26 so that the respective diaphragm rising portions 25a and 26a are in opposite directions, and are positioned with a predetermined interval,
Moreover, the bent portions 25b and 26b at the other ends of the flat portions of the mouth rings 25 and 26 are overlapped and closed and fixed. A bag-shaped space 27 is formed between the flat portions of the mouth rings 25 and 26. In addition to the effect of the embodiment shown in FIG. 7, this embodiment can increase the width and depth of the bag-shaped space 27.

The embodiment shown in FIG. 9 is the same as the embodiment shown in FIGS. 1 to 3 except that the sound absorbing material 28 is arranged on the wall surface of the bag-shaped space portion 6, and the embodiment shown in FIGS. In addition to the effects of the above embodiment, the noise of the vortex and the noise generated by the wing interference of the vortex are absorbed, so that the audibility is improved and the noise level is significantly reduced. As the sound absorbing material 28, a fibrous material such as glass wool or a porous material such as foamed soft urethane foam is suitable.

Of course, a sound absorbing material may be similarly arranged in the bag-shaped space in the embodiment shown in FIGS. 4, 5, 6, and 8.

In the embodiment shown in FIG. 10, the mouth ring 3
0 is a bag in which mouth rings 30aa and 30ab equivalent to the mouth rings 4 and 5 in FIG. 1 are continuously connected and integrated at a connecting portion 30c, and a bag having a tire-shaped cross section inside thereof. The shaped space forms 31. An opening 32 is formed on the opposite side of the outer end 30c, and the outer end 30c has a circular shape concentric with the opening 32.

With this configuration, in this embodiment, the configuration shown in FIG.
Compared with the embodiment shown in FIGS. 3A to 3C, it is particularly suitable for an industrial exhaust fan using a circular duct having a round outer diameter, and the mouth ring can be treated as one part. The performance is the same as that of the embodiment shown in FIGS. Although the mouth ring 30 has a tire-shaped cross section, it can be manufactured by using an elastic material such as a rubber that can be released from the mold.

The embodiment shown in FIG. 11 is the same as the embodiment shown in FIG. 10, but the two squeezing rising portions 33ba, 33bb of the mouth ring 33 are oriented in opposite directions to each other, and the bag formed inside the bag is formed. The opening 35 of the space portion 34 is enlarged.

With this configuration, in this embodiment, as shown in FIG.
-Compared to the embodiment shown in Fig. 3, it is particularly suitable for use in an exhaust fan having a round outer shape, for example, a circular duct, and the mouth ring can be treated as one part. The performance is the same as that of the embodiment shown in FIGS. Further, since the bag-shaped space portion 34 of the mouth ring 33 has a skirt-spreading shape, it can be manufactured by drawing a coil material of a flat iron plate by roller processing, and the material can be effectively used.

Of course, in the embodiment shown in FIG. 10, the mouth ring 30aa and 30ab may have the same direction of the squeeze rising portions, and in the embodiment shown in FIG. 11, the squeeze rising portions 33ba and 33bb of the mouth ring 30 may be the same. The directions may be the same. Further, in this and the embodiment shown in FIGS. 10 and 11, as in the embodiment shown in FIG. 9, a sound absorbing material may be arranged in the bag-shaped spaces 31, 34.

12 and 13 show an embodiment of an air conditioner (here, an outdoor unit of a separate room air conditioner) using the embodiment shown in FIGS. 1 to 3, and FIG. Is a longitudinal sectional view thereof, and FIG. 13 is a section line A of FIG.
It is the top view seen from -A, 40 is a bottom base, 41 is an upper case of an outdoor unit, 41a is a top plate, 41b, 41
c is a side plate, 42 is an axial fan, 42a is a blade, 43 is a fan motor, 44 is a heat exchanger, 45 is a front case and a guard,
46 and 47 are mouth rings, 46b and 47b are diaphragm rising portions, 48 is an opening portion, 49 is a bag-like space portion, and 50 is a vortex.

In FIGS. 12 and 13, the bottom base 40 is shown.
The upper case 41 of the unit including the upper plate 41a and the left and right side plates 41b and 41c is assembled to form a case of the outdoor unit. In such an outdoor unit, the outer shape and the cross section of the ventilation path are rectangular, which improves the installability.

Inside the case, a heat exchanger 44 is provided on the suction side (right side in FIG. 12), an axial fan 42 is provided on the opposite discharge side, and a fan motor 43 for rotating the same.
Mouth rings 46, 47 etc. are arranged respectively. 44
Is a heat exchanger and is arranged so as to face the suction side of the axial fan 42. The mouth rings 46 and 47 are axial fans 4
2 has the same structure as the mouth rings 4 and 5 shown in FIG. 1 and FIG. 3, but their inner circumferences are circular, whereas the outer circumferences are , Fig. 13
As is clear from the above, it has a rectangular shape similar to the cross-sectional shape of the outdoor unit, and is fixed to the upper case 41 and the bottom base 40 to partition the suction side and the discharge side.

As the mouth rings 46 and 47,
It goes without saying that the mouth ring described above other than FIGS. 1 and 3 may be used.

The mouth ring 46 is provided on the inner surface of the upper plate 41a.
The mouth rings 47 are arranged downstream (air discharge side) of the mouth rings 46 and are attached to the front end portions of the upper plates 41a, respectively, so that the bag-shaped space 49 is formed by the mouth rings 46, 47. Nose riser 4
An opening 48 of the bag space 49 is formed in an annular shape between 6b and 47b. Downstream throttling rising portion 47b
The aperture R of the shaft is reduced to 3% of the outer diameter of the axial fan. A front case and a guard 45 are arranged on the outer surface of the mouth ring 47 on the discharge port side. The outer surface of the mouth ring 47 on the discharge port side also serves as the front case of the outdoor unit.

In the air conditioner having such a configuration, when the axial fan 42 is rotated by the fan motor 43, air is sucked from the heat exchanger 44 side and heat is exchanged, and the axial flow inside the mouth rings 46 and 47 is increased. Fan 42,
It is discharged to the outside through the guard 45. In this case, the tips of the blades 42a of the axial fan 42 and the mouth rings 46, 47
As described above, the vortex 50 generated between the vortex 50 and the vortex 50 is sucked into the bag-shaped space 49, moves away from the blade 42a, and circulates in the natural body, and the growth of the vortex 50 is suppressed downstream thereof. Also, there is no backflow from the discharge side surface. As a result, the interference of the vortex 50 with the blades 42a is reduced and the noise is reduced. Along with this, similarly to the embodiment described with reference to FIGS. The effective diameter becomes large and a high air pressure is obtained, so that the air volume increases and the heat exchange amount increases.

When a refrigerating cycle is formed together with the heat exchanger 44 by using a compressor, the heat exchange is improved and the compression ratio of the refrigerant is reduced, so that COP (heat exchange amount / power consumption) is reduced. Further, by utilizing the increase in heat exchange amount for downsizing of the compressor, significant power saving can be realized. Further, by reducing the heat exchanger for which the air volume increases, the product can be downsized and the power consumption can be further reduced.

Furthermore, in this embodiment, since two mouth rings are structurally used, the optimum mouth rings 46 and 47 are selected in accordance with the load and the impeller thickness X of the axial fan 42. In addition to being able to adjust the position and the distance Y between them, since the drawing rise portions 46a, 47a of the mouth rings 46, 47 can be small, the mouth rings 46, 47 can be easily formed by shallow drawing by a press. You can Moreover, the mouth ring 46 is a base 40
And can be easily attached to the upper case 41,
Since the mouth ring 47 can be manufactured integrally as a front case, the cost of the product can be reduced.

[0052]

As described above, according to the present invention,
A first mouth ring and a second mouth ring, which divide the suction side and the discharge side, are arranged side by side on the outer peripheral side of the axial fan with a distance, and between the inner ends of the two mouth rings facing each other. By forming an annular opening with this, a bag-shaped space was formed in the cross section made by two mouth rings, so the vortex created at the tip of the wing is distant and the circulation of the vortex is smoothed,
In addition to suppressing the growth of vortices in the downstream, in addition to this, most of the discharge side surface of the mouth ring located downstream is dented in the direction perpendicular to the axial center of the axial fan or in the suction direction. Since backflow can be eliminated to reduce the interference of vortices with the blades and increase the blade area of the axial fan that actually blows air, low noise and high wind pressure performance can be obtained. Also, high efficiency of the fan can be obtained.

Further, by forming two mouth rings as one set, the axial thickness can be easily selected and manufactured according to the load, and the inner edge of the mouth ring can be easily pressed to be formed because the rise of the drawing is small. Since it is possible to change the size of the case and the size of the axial flow fan,
Many advantages can be obtained in production.

Further, when applied to an air conditioner, low noise and high air flow performance can be obtained, which not only contributes to power saving and downsizing, but also facilitates manufacturing and mounting work of the mouth ring. It is possible to provide an axial flow type blower having the advantage of.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a state where an axial flow type blower according to an embodiment of the present invention has a small load.

FIG. 2 is a front view of the embodiment shown in FIG.

FIG. 3 is a vertical cross-sectional view showing a state when the load of the embodiment shown in FIG. 1 is large.

FIG. 4 is a vertical sectional view showing another specific example of the mouth ring in FIG.

5 is a vertical sectional view showing still another specific example of the mouth ring in FIG.

FIG. 6 is a vertical cross-sectional view showing still another specific example of the mouth ring in FIG.

7 is a vertical sectional view showing still another specific example of the mouth ring in FIG.

FIG. 8 is a vertical cross-sectional view showing still another specific example of the mouth ring in FIG.

9 is a vertical sectional view showing still another specific example of the mouth ring in FIG.

10 is a vertical cross-sectional view showing still another specific example of the mouth ring in FIG.

FIG. 11 is a vertical cross-sectional view showing still another specific example of the mouth ring in FIG.

FIG. 12 is a vertical sectional view of an air conditioner showing a tenth embodiment of the present invention.

FIG. 13 is a cross-sectional view taken along the line AA of the air conditioner of FIG. 12 showing a tenth embodiment of the present invention.

FIG. 14 is a vertical cross-sectional view showing a state of an example of a conventional axial-flow blower when the load is small.

FIG. 15 is a vertical cross-sectional view showing a state when the load of the conventional example shown in FIG. 14 is large.

[Explanation of symbols]

 1 Axial fan 1a Blade 3 Circular tube case for air guide 4 Mouth ring 4a Throttling rising part 5 Mouth ring 5a Throttling rising part 6 Bag-shaped space 7 Vortex 8 Opening

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location F24F 1/00 316 6803-3L

Claims (12)

[Claims] 1. An axial flow blower comprising an axial fan and a mouth ring on the outer peripheral side of the axial fan that divides a suction side and a discharge side into a case. A structure in which the second mouth ring is perpendicular to the inner surface of the case, and most of the discharge side surface is dented in the case vertically or in the suction direction, except for the inner end squeezing rising portion of the second mouth ring located downstream. None, and the first and second mouth rings are arranged side by side with a predetermined distance in a direction parallel to the axis of the axial fan, and the shaft is provided between the first and second mouth rings. An axial flow type blower characterized in that a bag-shaped space having an opening facing the blade of a flow fan is formed. 2. The throttle riser, which is bent in a direction parallel to the axis of the axial fan, is provided at a tip of the first and second mouth rings on the axial fan side, and the throttle riser is provided. An axial flow type blower characterized in that the radius of curvature of the rising portion is set to 40% or less of the outer diameter of the axial flow fan. 3. The axial flow fan according to claim 2, wherein a sound absorbing material is arranged in the bag-shaped space. 4. The method according to claim 2 or 3,
An axial flow blower, wherein the second mouth ring has a flat surface portion perpendicular to the case, and the other is attached to the flat surface portion. 5. The method according to claim 2, wherein the first and second mouth rings are connected to each other by a connecting portion parallel to an inner surface of the case in a flat surface portion perpendicular to the inner surface of the case. A characteristic axial flow blower. 6. The method according to claim 2, 3, 4 or 5, wherein the leading ends of the aperture rising portions of the first and second mouth rings are opposed to each other, and the openings are formed between the leading ends. Axial flow type blower. 7. The squeezing rising portions of the first and second mouth rings face each other, and the tips of these squeezing rising portions are bent toward the bag-shaped space portion side according to claim 2, 3, 4, or 5. The axial flow type blower characterized by being. 8. The axial flow blower according to claim 2, 3, 4 or 5, wherein the directions of the rising portions of the first and second mouth rings are the same. 9. The axial-flow blower according to claim 2, 3, 4 or 5, wherein directions of the rising portions of the first and second mouth rings are opposite to each other. 10. The second mouth ring according to claim 2, wherein the first mouth ring and the second mouth ring are arcuate from a plane portion perpendicular to the inner surface of the case, and the tips are parallel to the axis of the axial fan. It has a bent squeezing rising portion, and the squeezing rising portion is reversed in direction, and a flat surface portion perpendicular to the inner surface of the case in the first and second mouth rings is closely attached. Axial blower. 11. A unit case formed by an upper case and a base, wherein:
The axial-flow blower according to 8, 9, or 10 is arranged, and a heat exchanger is provided on the suction side so as to face the axial-flow fan of the axial-flow blower, and a front case and a guard are provided on the discharge side. An air conditioner characterized by being arranged. 12. The first mouth ring according to claim 11, wherein the first mouth ring is arranged on a suction side with respect to the second mouth ring, and the first mouth ring is the upper case. The air conditioner attached to the base, wherein the second mouth ring is integrally formed with the front case.