JPH11270495A - Impeller for centrifugal blower and centrifugal blower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an impeller for centrifugal blower which can establish the calmness. SOLUTION: An impeller 1 for centrifugal blower is composed of a main plate 2 in a disc shape, a plurality of vanes 3 fixed in row along the outer edge of the main plate 2, and a side plate 4 which is installed opposing to the main plate 2 and is to fix the vanes 3 in cooperation with the main plate 2, wherein the side plate 4 is equipped with a gas/air suction amount restricting hole 5 for restricting the suction amount of gas/air to be inhaled into the impeller 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an impeller for a centrifugal blower and a centrifugal blower for use in a water heater, a boiler, an air conditioner, a copying machine, and the like for feeding air.

[0002]

2. Description of the Related Art When a centrifugal blower (hereinafter, also referred to as a "blower") is attached to a boiler or the like to feed air for combustion, in order to improve the combustion efficiency of the boiler, discharge of air discharged from the blower is required. It is necessary to regulate the amount appropriately. In this case, a method of controlling the discharge amount by controlling the rotation speed of the impeller of the blower can be considered.
However, in this method, when the ventilation pipe between the blower and the boiler body is long, or when passing through a dustproof filter, if the rotation speed of the impeller is controlled to a low speed,
Since the static pressure of the discharge air is weak, the discharge air of the blower may not be reliably blown to the boiler body. For this reason, the applicant has already developed a blower capable of controlling the discharge amount while maintaining an appropriate static pressure by controlling the amount of air sucked into the blower.

[0003] The blower 41 which the applicant has already developed.
As shown in FIGS. 8 and 9, the casing 11 and the impeller 3
1, a suction amount regulating plate 45 and a motor 20 for rotating the impeller 31 are provided.

[0004] As shown in FIG. 8, the casing 11 is provided with a bottom plate 12 in which a rotation shaft penetration hole (not shown) for penetrating the rotation shaft 24 of the motor 20 is formed. A top plate 1 having an opening 11b for inserting a car 31 and sucking air during rotation.
3 and a peripheral plate 14 bent along the outer edges of the bottom plate 12 and the top plate 13, and a discharge port 11 a is formed by opening both ends of the peripheral plate 14. As shown in the figure, the impeller 31 includes a disk-shaped main plate 32 on which a hub 35 fixed to the rotating shaft 24 is mounted, and a plurality of blades 33, 3 mounted along the outer edge of the main plate 32.
The main plate 32 is disposed opposite to the main plate 32.
, And a ring-shaped side plate 34 for holding the blades 33, 33,. On the other hand, the suction amount regulating plate 45 is formed in a disk shape whose outer diameter is larger than the opening 11b of the casing 11, and has a suction H at a center defined by the diameter H1 according to the air suction amount. A mouth 46 is formed.

In the blower 41, when the impeller 31 is rotated, the air in the inner space S of the impeller 31 is discharged from the gaps between the blades 33, 33, as shown by arrows A1, A2 in FIG. As shown by the arrow E in FIG. 9, the ink is discharged from the discharge port 11a through the discharge path R in the casing 11. Accordingly, the air outside the casing 11 is
As shown by arrows B1 and B2 of 0, the air is sucked into the inner space S of the impeller 31 through the suction port 46 of the suction amount regulating plate 45, and at this time, a predetermined suction is performed according to the opening area of the suction port 46. Regulated by quantity.

As described above, in the blower 41, the diameter H 1 of the suction port 46 in the suction amount regulating plate 45 is appropriately changed according to the suction amount, so that the suction from the outside of the casing 11 to the inside space S of the impeller 31. The amount of air to be discharged is regulated to an appropriate amount, whereby the amount of air discharged from the discharge port 11a is regulated to an appropriate amount, and the static pressure of the discharged air is to be maintained at an appropriate value.

[0007]

However, the blower 41 already developed by the applicant has the following points to be improved. First, in the blower 41, as shown by arrows C1 and C2 in FIG. 10, the suction port 46 is formed by the pressure difference between the air in the inner space S of the impeller 31 and the air in the discharge path R.
A part of the air sucked from the outlet may leak into the discharge path R from a gap between the side plate 34 of the impeller 31 and the top plate 13 of the casing 11. Conversely, when a high load is applied to the air discharged from the discharge port 11a, the arrow D1 in FIG.
As indicated by D2, a part of the air in the discharge path R to be discharged from the discharge port 11a may flow back to the inner space S of the impeller 31 from the gap between the side plate 34 and the top plate 13. In these cases, since the air circulates through the casing 11 via the impeller 31, the intake air and the air to be discharged interfere with each other, so that the air discharge amount, the static pressure, and the impeller A surging phenomenon in which the rotation speed of the motor 31 fluctuates periodically occurs. For this reason, there is a problem that the blower 41 vibrates due to the surging phenomenon and may generate an unpleasant sound. Second, the impeller 31
Depending on the rotational speed of the air blower and the load state of a boiler or the like to which the blower 41 is attached, a part of the air to be discharged flows back into the inner space S of the impeller 31, so that the blower 41 The discharge amount and static pressure of air to be discharged from 11a may become unstable,
There is a request that this be improved.

[0008] The present invention has been made in view of the above points to be improved, and has as its main object to provide an impeller for a centrifugal blower and a centrifugal blower capable of reducing noise. It is another object of the present invention to provide an impeller for a centrifugal blower and a centrifugal blower capable of stabilizing a blowing capacity such as a gas discharge amount and a static pressure.

[0009]

According to a first aspect of the present invention, there is provided a centrifugal blower impeller having a disk-shaped main plate and a plurality of disks fixed in rows along the outer edge of the main plate. In a centrifugal blower impeller including a blade and a side plate that is arranged opposite to the main plate and fixes a plurality of blades together with the main plate, the side plate has a suction amount of gas sucked into the centrifugal blower impeller. It is characterized in that a suction amount regulating hole for regulating is formed.

According to a second aspect of the present invention, there is provided a centrifugal blower including the impeller for a centrifugal blower according to the first aspect. The “centrifugal blower” in the present invention includes a so-called “centrifugal fan” and a “centrifugal blower”.

In the impeller for a centrifugal blower according to the first aspect and the centrifugal blower according to the second aspect, a suction amount regulating hole is formed in a side plate of the impeller. Therefore, when the impeller is rotated, an appropriate static pressure is applied to the gas discharged from the centrifugal fan, and in that state, the gas around the centrifugal fan is
It is absorbed into the inner space of the impeller through the suction amount regulating hole, and at this time, the suction amount is regulated to the desired suction amount prescribed in advance by the suction amount regulating hole. On the other hand, most of the gas sucked into the impeller is discharged from the discharge port after being discharged from the gap between the blades, and only a part of the gas is leaked from the gap between the impeller and the casing of the centrifugal blower. In this case, the leaked gas is
Once leaked out of the impeller, it becomes part of the outside air. As a result, the circulation of the gas in the centrifugal blower via the impeller is prevented, and as a result, the degree of the surging phenomenon is reduced, whereby the noise is reduced.

A centrifugal blower according to a third aspect of the present invention is the centrifugal blower according to the second aspect, wherein an opening formed on a side surface of the casing for accommodating the impeller for the centrifugal blower on the side of the gas suction direction, and accommodated in the casing. And a closing means for closing a gap between the impeller for a centrifugal blower in a closed state and a side plate.

In this centrifugal blower, for example, a ring-shaped cover or the like as closing means closes a gap between an opening formed in the casing and a side plate of the impeller. In this state, the gas once discharged from the inside of the impeller to the discharge path of the centrifugal blower is always discharged from the discharge port without leaking to the outside of the centrifugal blower. Therefore, intrusion of gas into the discharge passage of the centrifugal blower from a portion other than the suction amount regulating hole of the impeller and leakage of gas from the discharge passage to the outside of the centrifugal blower are completely prevented. That is, all of the gas sucked from the suction amount regulating hole of the impeller is discharged from the discharge port, and only gas sucked from the suction amount regulating hole of the impeller is discharged from the discharge port. As a result, the circulation of gas in the centrifugal blower via the impeller is completely cut off, stabilizing the blowing capacity and causing interference between the intake air and the air to be discharged from the discharge port. Since the occurrence of the surging phenomenon itself is completely prevented, noise can be reliably reduced.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a centrifugal blower according to an embodiment of the present invention; Note that the same components as those of the blower 41 already developed by the applicant are denoted by the same reference numerals, and redundant description will be omitted.

First, a configuration and an assembling method of an impeller 1 corresponding to an impeller for a centrifugal blower according to the present invention will be described with reference to FIGS.

As shown in FIG. 1, the impeller 1 has a main plate 2 formed in a disk shape, blades 3, 3... Formed with insertion feet 3a, 3b at both ends, and a ring-shaped side plate 4. It is provided with. In this case, mounting holes 2a, 2a,... Through which the insertion feet 3a of the blades 3 can be press-fitted are formed in the main plate 2 in a row along the outer edge thereof, and the rotating shaft 24 of the motor 20 penetrates. A possible through hole 2b is formed in the center. Each of the blades 3, 3,... Is formed by bending a plate-shaped member, and is formed identically. The side plate 4 has a mounting hole 4 into which the insertion foot 3b of the blade 3 can be pressed.
are formed in a row along the outer edge thereof, and a central portion thereof corresponds to a suction amount regulating hole in the present invention, and has an inlet having a diameter H2 corresponding to a specified suction amount of air. 5
Are formed.

When assembling the impeller 1, first,
The insertion feet 3a of the blades 3 are pressed into the mounting holes 2a of the main plate 2, respectively, and the insertion feet 3b are pressed into the mounting holes 4a of the side plate 4, respectively. Next, the leading ends of the insertion feet 3a and 3b projecting from the main plate 2 and the side plate 4 are bent, and the blades 3 are sandwiched between the main plate 2 and the side plate 4, thereby integrating the main plate 2, the side plate 4 and the blades 3. . Thereby, as shown in FIG. 2, the impeller 1 is completed.

Next, the structure of the blower 10 having the impeller 1 will be described with reference to FIGS.

The blower 10 is provided with an impeller 1, a casing 11, a cover 15, and a motor 20 for rotating the impeller 1, as shown in both figures.

As shown in FIG. 4, the casing 11 includes a bottom plate 12, a top plate 13, and a peripheral plate 14. The bottom plate 12 has four screw holes 12a to 12d for fixing the motor 20 (only 12b and 12d are shown in the figure), and a rotating shaft for penetrating the rotating shaft 21 of the motor 20. Holes (not shown) are respectively formed. The top plate 13 has four screw holes 13 a to 13 d for fixing the cover 15.
b is formed along the outer periphery. The cover 15 corresponds to the closing means in the present invention, and has an outer diameter larger than the opening 11 b of the top plate 13 and an inner diameter equal to the side plate 4 of the impeller 1.
And four bolt holes 15a to 15d are formed at positions facing the screw holes 13a to 13d of the casing 11 during assembly. As shown in FIG. 5, the inner edge 15e of the cover 15 is bent substantially at a right angle. In an assembled state, the opening 11b of the casing 11 and the side plate 4 of the impeller 1 are formed.
To close the gap. As shown in FIG. 4, a screw thread is formed on the rotating shaft 21 of the motor 20 so that the flange nut 18 for fixing the impeller 1 can be tightened.
A stopper 21a is formed to abut the main plate 2 of the impeller 1 via the washer 16 during assembly to regulate the position.

Next, the assembly of the blower 10 will be described.

First, the rotary shaft 21 of the motor 20 is passed through the rotary shaft through hole of the casing 11, and the tip of the rotary shaft 21 is projected into the internal space of the casing 11. next,
Spacers 22a to 22d (in FIG.
The bolts 23a to 23d (only the bolts 23a to 23c are shown in the figure) are sandwiched between the bottom plate 12
Bolts into the screw holes 12a to 12d. Thereby, the motor 20 and the casing 11 are integrated. Next, the washer 16 is made to penetrate the rotating shaft 21 protruding into the internal space of the casing 11, and the washer 16 is brought into contact with the stopper 21 a of the rotating shaft 21.
The impeller 1 is inserted from the first opening 11b, and the rotating shaft 21 is passed through the through hole 2b. Subsequently, the rotating shaft 21
, The main plate 2 of the impeller 1 is sandwiched between the washers 16 and 17, and the flange nut 18 is fastened to the rotating shaft 21, thereby fixing the impeller 1 to the rotating shaft 21. Next, the bolt hole 15 of the cover 15
The cover 15 is fixed to the casing 11 by bolting bolts 19a to 19d penetrating through a to 15d into screw holes 13a to 13d in the top plate 13 of the casing 11, respectively. Thereby, as shown in FIG.
The blower 10 is completed.

Next, the operation principle of the blower 10 will be described.
This will be described with reference to FIG.

In the blower 10, when the impeller 1 is rotated by supplying a predetermined electric power to the motor 20,
As shown by arrows A1 and A2 in the figure, the air in the inner space S of the impeller 1 is discharged from the gap between the blades 3 to the discharge path R, and is discharged from the discharge port 11a in the direction of the arrow E in FIG. You. Accordingly, as shown by arrows B1 and B2 in FIG. 5, outside air of the casing 11 is sucked into the inner space S of the impeller 1 through the suction port 5 of the side plate 4 of the impeller 1. It is regulated to the desired inhalation amount. In this case, the side plate 4
Compared to the conventional side plate 34, the surface area is formed larger, so that the strength of the impeller 1 is improved. For this reason, the deflection of the impeller 1 during rotation can be prevented,
The noise level generated due to the deflection of the impeller 1 can be reduced.

On the other hand, in the blower 10, the cover 15 closes the gap between the opening 11 b of the casing 11 and the side plate 4 of the impeller 1. Therefore, the inner space S of the impeller 1
Is discharged only in the directions indicated by arrows A1 and A2 in FIG. In addition, the outside air that is going to flow into the discharge path R of the casing 11 in the directions indicated by the arrows C1 and C2 in the same figure is prevented from entering by the edge 15e of the cover 15. Further, the air once discharged from the impeller 1 to the discharge path R is applied to the casing 11 in a direction indicated by arrows D1 and D2 in FIG.
Even if it tries to leak outside, the edge portion 15e prevents the leak. For this reason, in the blower 10, all of the air sucked into the inner space S through the suction port 5 of the impeller 1 and once discharged to the discharge path R is removed from the centrifugal blower 10.
The air is always discharged from the discharge port 11a without being leaked to the outside, and only the air sucked from the suction port 10 is discharged from the discharge port 11a. Therefore, the circulation of the air in the casing 11 through the impeller 1 is completely cut off. Therefore, in this blower 10, the blowing capacity is stabilized, and the sucked air and the air should be discharged from the discharge port 11a. Since the occurrence of the surging phenomenon itself due to the interference with the air can be completely prevented, noise can be reliably reduced. According to the experiment by the inventor, the noise level in the normal rotation speed region of the blower 10 is reduced by 2 to 3 dB as compared with the blower 41. Therefore, 0.
In today's competition of reducing the noise level by one decibel, the blower 10 can be said to be an extremely innovative blower.

In the blower 10, the washer 1
Since the impeller 1 is fixed to the rotary shaft 21 by the flanges 6, 17 and the flange nut 18, the impeller is compared with a conventional blower 41 in which the impeller 31 is fixed to the rotary shaft 24 via the hub 35. As a result, the volume of the piece projecting into the inner space S can be reduced, so that air can be more smoothly sucked. For this reason, since the suction noise can be reduced, the noise can be further reduced, and the blowing ability can be improved.

The present invention is not limited to the configuration shown in the embodiment of the present invention. For example, in the embodiment of the present invention, the gap between the opening 11 b and the side plate 4 of the impeller 1 is closed by the cover 15.
As shown in (1), an edge 13e corresponding to the edge 15e of the cover 15 may be formed on the top plate 13 of the casing 11 itself. Further, as shown in FIG.
1c, the impeller 1 may be inserted from the bottom plate 12 side, and the motor 20 may be fixed to the bottom plate 12 of the casing 11 using the fixing plate 25. In this case, the opening 1
It is preferable that the diameter of 1b is smaller than the diameter of the side plate 4 of the impeller 1.

Further, in the embodiment of the present invention, the blades 3 are bent by press-fitting the insertion feet 3a, 3b of the blade 3 into the mounting holes 2a of the main plate 2 and the mounting holes 4a of the side plates 4. 3 is fixed to the main plate 2 and the side plate 4, but the method of fixing the blade 3 is not limited to this. For example, the blade 3 may be fixed by welding or the like, or the main plate 2, the blade 3 and the side plate 4 may be fixed by resin. It may be integrally molded.

[0029]

As described above, according to the impeller for a centrifugal blower according to the first aspect and the centrifugal blower according to the second aspect,
By forming a suction amount regulating hole in the side plate for regulating the amount of gas sucked into the centrifugal fan impeller, when the impeller is mounted on the fan and rotated, centrifugation through the impeller is performed. Since the circulation of gas in the blower can be prevented, the generation level of unpleasant noise caused by the surging phenomenon can be reduced, and as a result, noise can be reduced.

According to the centrifugal blower of the third aspect, the closing means closes the gap between the opening formed in the side surface of the casing and the side plate of the impeller for the centrifugal blower. Can be completely prevented, whereby the noise can be reliably reduced.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an impeller according to an embodiment of the present invention.

FIG. 2 is a perspective view of the impeller according to the embodiment of the present invention.

FIG. 3 is a perspective view of the centrifugal blower according to the embodiment of the present invention.

FIG. 4 is an exploded perspective view of the centrifugal blower according to the embodiment of the present invention.

FIG. 5 is a sectional view showing a flow of air when the centrifugal blower according to the embodiment of the present invention is operated.

FIG. 6 is a sectional view of a centrifugal blower according to another embodiment.

FIG. 7 is a sectional view of a centrifugal blower according to still another embodiment.

FIG. 8 is an exploded perspective view of a centrifugal blower already developed by the applicant.

FIG. 9 is a perspective view of a centrifugal blower already developed by the applicant.

FIG. 10 is a sectional view showing the flow of air when a centrifugal blower already developed by the applicant is operated.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 impeller 2 main plate 3 blade 4 side plate 5 suction port 10 blower 11 casing 11b opening 13 top plate 13e edge 15 cover 15e edge

Claims (3)

[Claims] 1. A main plate formed in a disk shape, a plurality of blades fixed in a row along an outer edge of the main plate, and the plurality of blades arranged in opposition to the main plate together with the main plate. A centrifugal blower impeller having a fixed side plate, wherein the side plate is formed with a suction amount regulating hole for regulating a suction amount of gas sucked into the centrifugal blower impeller. Centrifugal blower impeller. 2. A centrifugal blower comprising the centrifugal blower impeller according to claim 1. 3. An opening formed in a side surface of the casing accommodating the centrifugal blower impeller on the side of the gas suction direction, and the side plate of the centrifugal blower impeller stored in the casing. 3. A closing means for closing a gap between the two.
The centrifugal blower as described.