JP2002202094A - Centrifugal blower and vehicle air-conditioner equipped with it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a centrifugal blower and a vehicle air-conditioner equipped with it capable of achieving enhanced fan characteristics without bringing about large-sized construction of the device. SOLUTION: The peripheral edge of a main plate 11c is formed approximately in a wavy shape in which auxial blade side passages 21 formed as recessed toward the main blades 11b and main blade side passages 22 formed as recessed oppositely to the auxial blade side passages 21 are alternately arranged continuously, wherein the main blades 11b are positioned in such a way as pinching each main blade side passage 22 from the sides.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a centrifugal blower for blowing a fluid introduced into an impeller by the rotational centrifugal force of the impeller, and a vehicle air conditioner provided with the centrifugal blower.

[0002]

2. Description of the Related Art An example of this type of conventional centrifugal blower is shown in FIG.
And FIG. 6 is a sectional view taken along the line AA of FIG. 7, and FIG. 7 is a sectional view taken along the line BB of FIG. Centrifugal blower 1
Comprises an impeller 2, a motor 3 for driving the impeller 2 to rotate, a casing 4 for housing the impeller 2 and the motor 3, and a bell mouth 5 for introducing air toward the impeller 2 in the casing 4. It has a schematic configuration.

[0003] The impeller 2 has a plurality of main blades 2b arranged in parallel with and around the axis 2a of the impeller 2, a main plate 2c to which the lower end edges of these main blades 2b and the shaft 3a of the motor 3 are fixed. A plurality of sub-blades 2d fixed to the back side of the main plate 2c on which the main blades 2b are fixed, and a reinforcing ring 2e for fixing the upper end of each main blade 2b from the periphery. . The shape of the main plate 2c is raised at the center where the motor 3 is housed, and the annular portion around the raised center has a flat disk shape. The main plate 2c is connected to each main blade 2b and each sub blade 2d.
Has only the role of fixing the front and rear sides of the front and back sides. The casing 4 has a substantially snail-like outer shape when viewed from the line of sight in FIG. 7, and the bell mouth 5 is integrally provided on one side wall 4a (see FIG. 6). The bell mouth 5 has a ring shape tapered from the one side wall 4a toward the impeller 2, and is arranged coaxially with the impeller 2.

According to the centrifugal blower 1, when the motor 3 is started, the impeller 2 rotates around the axis 2a, and the suction flow SA taken into the impeller 2 via the bell mouth 5 is generated by centrifugal force. It is sent out around the outside of the impeller 2. The suction flow SA sent out in this way is guided to the discharge port 6 along the inner wall surface of the casing 4, and is discharged out of the casing 4 via the discharge port 6.

[0005]

By the way, in the conventional centrifugal blower 1 described above, it is desired to improve the fan characteristics of the main blades 2b by ensuring the effective blade width of the main blades 2b as long as possible. In detail, for example, when the outer diameter of the impeller 2 is D2 and the length in the direction of the axis 2a is B, the aspect ratio B / D2 is taken on the horizontal axis, and the air volume Q is taken on the vertical axis. Figure 8 shows the fan characteristics.
The tendency shown in FIG. That is, as the aspect ratio B / D2 gradually increases, the air volume Q increases, and after reaching the peak point P, the air volume Q gradually decreases. Since the aspect ratio B / D2 of the peak point P is approximately 0.8, it is desirable to increase the aspect ratio B / D2 to approximately 0.8 in order to obtain high fan characteristics. However, since this type of device generally requires a reduction in size, it is necessary to suppress the length B of the impeller 2 to a practical length.

With this background, the length of each main blade 2b is increased to improve the fan characteristics and the aspect ratio B / D is increased.
Although there is a demand to increase the ratio 2, in practice, there is a problem that the aspect ratio B / D2 of about 0.4 to 0.7 has to be selected due to the limitation due to the demand for downsizing of the apparatus. Was. That is, the downsizing of the apparatus has hindered the improvement of the fan characteristics.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a centrifugal blower capable of achieving a further improvement in fan characteristics without increasing the size of the device, and a vehicular air conditioner provided with the same. Aim.

[0008]

The present invention employs the following means in order to solve the above-mentioned problems. That is, the centrifugal blower according to claim 1 of the present invention has an impeller including a plurality of main blades arranged in an annular shape and a main plate to which the edges of the main blades are joined, and is incorporated into the impeller. In the centrifugal blower that blows the fluid by the rotational centrifugal force of the impeller, the outer peripheral edge of the main plate is formed so as to be concave toward each of the main blades when the outer peripheral edge is viewed from the side. Sub-blade side flow path,
The sub-blade-side flow path and the main blade-side flow path formed so as to be recessed toward the opposite side form a substantially corrugated shape in which the main blade-side flow paths are alternately and continuously arranged. Is disposed at a position sandwiching from both sides.

According to the centrifugal blower of the first aspect,
When the impeller is rotated, the centrifugal force causes the fluid to be sent out of the impeller so as to pass through the gap flow path between the main blades. At this time, the gap flow passage effective for sending out the fluid has conventionally been the same length as the entire length of each main blade, but in the present invention, the main blade side flow is added to the entire length of each main blade. Since the length of the road is increased by the addition of the depth, the overall length of each main blade becomes as long as the depth, and the amount of air to be blown can be increased. In addition, since each main blade itself does not actually become longer than before, the size of the impeller does not increase.

According to a second aspect of the present invention, there is provided a vehicle air conditioner including the centrifugal blower according to the first aspect. According to the vehicle air conditioner of the second aspect, since the centrifugal blower having high fan characteristics while being compact is equipped, the air conditioner itself can be further improved in air conditioning performance without being enlarged. Will be able to

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A centrifugal blower according to the present invention is a device for blowing a fluid introduced into an impeller by the rotational centrifugal force of the impeller. One embodiment of the device will be described below with reference to FIGS. However, it goes without saying that the present invention is not limited to this. In the following description, an example in which the centrifugal blower of the present invention is applied to a vehicle air conditioner will be described. FIG.
FIG. 3 is a view showing the centrifugal blower of the present embodiment, and is a cross-sectional view taken along line CC of FIG. 2. FIG. 2 is a sectional view taken along line DD of FIG. FIG. 3 is a diagram showing a main part of the main plate, and is a partial side view taken along line EE in FIG. Also,
FIG. 4 is a perspective view of the main plate. Also, FIG.
It is a part enlarged view.

As shown in FIGS. 1 and 2, a centrifugal blower 10 of the present embodiment comprises an impeller 11, a motor 12 for rotating the impeller 11, a casing 13 for accommodating the impeller 11 and the motor 12, and Bellmouth 1 for introducing air toward impeller 11 in casing 13
4 and a bypass pipe 17 connecting the suction port 15 and the discharge port 16 of the nose N of the casing 13.

The casing 13 is a box having a substantially snail-like outer shape when viewed from the line of sight in FIG. 2, and has a side wall 13a integrally formed with the bell mouth 14 (FIG. 1).
And a side wall 13b parallel to and opposed to the side wall 13a.
And the peripheral edge between these side walls 13a and 13b is
And a peripheral wall 13c to be joined. The shaft 12a of the motor 12 is provided on the side wall 13a.
The bell mouth 14 is integrally formed so as to be coaxial. The bell mouth 14 tapers from the side wall 13a toward the impeller 11 and is viewed from a cross section including the axis thereof (that is, viewed from the line of sight of FIG. 1).
Has a curved shape convex toward the inner peripheral side. Therefore, the inner peripheral surface of the bell mouth 14 forms a circular flow path in which the flow path area from the inlet 14a to the outlet 14b gradually narrows. The side wall 13b is formed with through holes for passing the suction port 15 and the discharge port 16, respectively. Then, a part of the flow on the nose N side is sucked from the suction port 15 and is discharged to the motor 12 from the discharge port 16 via the bypass pipe 17 so that the motor 12 can be cooled.

The impeller 11 has a plurality of main blades 11 parallel to its axis 11a (the same axis as the shaft 12a of the motor 12) and arranged annularly around the axis 11a.
b, the lower edge of each of these main blades 11b and the motor 1
It comprises a main plate 11c to which the second shaft 12a is fixed, and a reinforcing ring 11d for fixing the end of each main blade 11b on the side opposite to the main plate 11c. Each main blade 11b is a wing that is long in the direction of the axis 11a and, as shown in FIG. 2, is inclined so as to form a predetermined angle with respect to the radial direction of the axis 11a. The main blades 11b are arranged at equal pitch intervals from each other, and each gap formed between the main blades 11b expands with a twist from the center of the impeller 11 (the axis 11a) to the outside. The gap flow path 11f is formed.

As shown in FIG. 1, the main plate 11c is a disk having a raised central portion for accommodating the motor 12, and the main blades 11b are fixed to the upper surface thereof. The shaft 12a of the motor 12 is connected to the center of the main plate 11c. On the other hand, the motor 12
It is fixed to the side wall 13b of the casing 13. As shown in FIGS. 3 and 4, when the outer peripheral edge of the main plate 11 c is viewed from the surrounding side, each main blade 1 c
A sub-blade-side flow path 21 formed so as to be recessed toward the side where 1b is fixed, and a main blade-side flow path 22 formed so as to be recessed toward the side opposite to the sub-blade side flow path 21. Have a substantially wave shape alternately and continuously arranged. Then, as shown in FIGS. 2 and 3, each main blade 11b is arranged at a position sandwiching the main blade side flow path 22 from both sides.

As shown in FIG. 2, the main blade-side flow path 22 is located at the center of the main plate 11c (the axis 11).
a) a flow path whose flow path depth and width gradually increase with twisting in one direction from a) toward the outer peripheral edge side,
A plurality is annularly arranged around the center of the main plate 11c. The twisted shape of the main blade side flow path 22 is the same as each of the gap flow paths 11f as shown in the figure, and the main blade side flow path 22 and the gap flow path 11f are substantially integrated. One flow path is formed.

When viewed from the back side (the back side in FIG. 2) of the side on which the main blade side flow path 22 is formed, the auxiliary blade side flow path 21 extends from the center (the axis 11a) of the main plate 11c to the outer peripheral edge. The flow path is such that the flow path depth and the flow path width gradually increase while being twisted in one direction toward the portion, and the main plate 11c
Are arranged in a ring around the center of. When viewed through the main plate 11c, these sub-blade-side flow paths 21 have the same shape as the main blade-side flow path 22 and have a twist in the same direction. Therefore, in the main plate 11c of the present embodiment, the protruding wall portion forming the sub-blade-side flow path 21 substantially serves as a sub-blade (the sub-blade 2d described in the related art).

When the impeller 11 is manufactured by injection molding, the main plate 11c and each of the main blades 11b may be formed as separate parts and then joined together, or they may be integrally formed from the beginning. It is good also as what is shape | molded in the turned state. However, it is of course more preferable from the viewpoint of manufacturing cost to integrally form the two from the beginning, since the number of parts and the number of manufacturing steps can be reduced.

The centrifugal blower 10 having the configuration described above
Will be described below with reference to FIGS. 1 and 5. First, when the motor 12 is started, the impeller 11 rotates around the axis 11a, takes in the suction flow SA into the impeller 11 via the bell mouth 14, and sends it out to the outer periphery of the impeller 11 by centrifugal force. The suction flow SA sent out in this manner is guided to the discharge port 18 along the inner wall surface of the casing 13, and is discharged out of the casing 13 through the discharge port 18. On the other hand, by the rotation of the main plate 11c, the flow in the space of the impeller 11 on the side where the motor 12 is arranged is sent to the outer periphery of the impeller 11 by centrifugal force. Then, a negative pressure is generated in the space of the impeller 11 to form a flow that sucks a part of the flow on the nose N side. Then, the motor 12 is cooled by this flow.

At this time, the flow path for sucking out the flow SA out of the impeller 11 on the side of the main blade 11b of the main plate 11c has conventionally been able to secure only the gap flow path having the same length as the entire length of each main blade 2b. On the other hand, in the present embodiment, as shown in FIG. 5, the total length L of the main blade 11b is increased by adding the depth dimension d of the main blade side flow path 22, so that the total length of the main blade 11b is reduced. It becomes longer by the depth dimension d, and the amount of air can be increased. This is due to an increase in the centrifugal force due to the extension of the effective blade width (addition of centrifugal force to the extent that the main plate side flow path 22 makes) and an increase in the flow path area due to the addition of the main plate side flow path 22. Moreover, each main blade 11b
The impeller is not longer than before, so the impeller 11
Does not increase in size.

According to the centrifugal blower 10 of the present embodiment described above, two effects of (1) improvement of fan characteristics and (2) noise reduction can be achieved. That is, (1) According to the centrifugal blower 10 of the present embodiment, the length obtained by adding the concave depth d of the main plate-side flow path 22 to the total length L of each main blade 11b is substantially effective for the impeller 11. Since the blade width can be set, the effective blade width can be secured long without increasing the total length of each main blade 11b. Accordingly, while maintaining the axial length of the impeller 11 as before, the fan width can be increased by increasing the effective blade width, thereby further improving the fan characteristics without increasing the size of the device. It is possible to do.

(2) In FIG. 5, when the flow near the bell mouth 14 in the direction of the axis 11a is denoted by V1, the flow near the main plate 11c is denoted by V2.
If c is a simple flat disk shape as in the prior art, V2> V
1 is obtained. In contrast, the main plate 11c of the present embodiment
In this case, the suction flow SA flows into the main plate-side flow path 22 by the addition of the main plate-side flow path 22, and the flow velocity here decreases. In general, since the energy of sound is proportional to the fifth to sixth powers of the flow velocity, a decrease in the flow velocity lowers the energy of the sound, whereby the noise can be reduced.

By providing the centrifugal blower 10 described above, according to the vehicle air conditioner of the present embodiment, it is possible to further improve the air conditioning performance without increasing the size of the air conditioner itself. .

In the above embodiment, the case where the centrifugal blower 10 is provided in a vehicle air conditioner has been described as an example. However, the present invention is not limited to this, and the centrifugal blower of the present invention may be applied to other uses. Of course.

[0025]

According to the centrifugal blower according to the first aspect of the present invention,
A configuration in which the outer peripheral edge of the main plate has a roughly corrugated shape in which sub-blade-side flow paths and main blade-side flow paths are alternately and continuously arranged, and each main blade is arranged at a position sandwiching each main blade-side flow path from both sides. It was adopted. According to this configuration, the length obtained by adding the recess depth of the main plate-side flow path to the total length of each main blade can be used as the substantial effective blade width of the impeller.
The effective blade width can be increased without increasing the overall length of each main blade. Therefore, while the axial length of the impeller is maintained as before, the fan width can be increased by increasing the effective blade width, thereby further improving the fan characteristics without increasing the size of the device. It becomes possible.

According to the second aspect of the present invention, since the centrifugal blower having high fan characteristics while being compact is provided, the air conditioning performance is further improved without increasing the size of the air conditioner itself. Can be achieved.

[Brief description of the drawings]

FIG. 1 is a view showing one embodiment of a centrifugal blower of the present invention, and is a cross-sectional view taken along the line CC of FIG. 2;

FIG. 2 is a view showing the centrifugal blower, and is a view similar to FIG.
It is D sectional drawing.

FIG. 3 is a view showing a main part of a main plate of the centrifugal blower, and is a partial side view as seen from a line EE in FIG. 2;

FIG. 4 is a perspective view showing a main plate of the centrifugal blower.

FIG. 5 is a view showing a main part of the centrifugal blower, and FIG.
It is an enlarged view of the F section.

6 is a view showing a conventional centrifugal blower, and is a cross-sectional view along AA in FIG. 7;

FIG. 7 is a sectional view of the centrifugal blower taken along the line BB in FIG. 6;

FIG. 8 is a graph showing the relationship between the shape of the centrifugal blower and the fan characteristics, with the horizontal axis representing the aspect ratio B / D2 and the vertical axis representing the air flow rate Q.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Centrifugal blower 11 ... Impeller 11b ... Main blade 11c ... Main plate 21 ... Sub blade side flow path 22 ... Main blade side flow path SA ... Suction flow (fluid)

Claims (2)

[Claims] 1. An impeller having a plurality of main blades arranged in an annular shape and a main plate to which edges of the main blades are joined, and a fluid introduced into the impeller is centrifuged by a rotary centrifuge of the impeller. In a centrifugal blower that blows by force, the outer peripheral edge of the main plate is a sub-blade-side flow path formed to be concave toward each of the main blades when the outer peripheral edge is viewed from the surrounding side. The sub-blade-side flow path and the main blade-side flow path formed so as to be recessed toward the opposite side form a substantially corrugated shape in which the main blade-side flow paths are alternately and continuously arranged. A centrifugal blower, which is arranged at a position sandwiching the よ り from both sides. 2. A vehicle air conditioner comprising the centrifugal blower according to claim 1.