JP3391318B2 - Centrifugal fan and air conditioner equipped with the fan - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a centrifugal fan and an air conditioner including the fan.

[0002]

2. Description of the Related Art FIG. 16 shows a conventional general centrifugal fan 5
The main part of 0 is shown. The centrifugal fan 50 includes an outer peripheral portion of a hub 51 that is connected to a motor 54 and is rotationally driven.
A vane 53 having a curved plate shape is provided between the hub 51 and the shroud 52 between the outer periphery of the shroud 52 which is provided with a suction port 56 at its center and is opposed to the hub 51 at a predetermined interval. It is configured by arranging a plurality of sheets at predetermined intervals in the circumferential direction. And this centrifugal fan 50
The air A sucked from the suction port 56 by being rotationally driven by the motor 54 is, as shown by a streamline A in the figure, an air outlet 57 opened to the outer peripheral surface by the respective blades 53, 53, ... It is designed to blow out to the outside in the radial direction.

By the way, in such a centrifugal fan 50, there is a tendency to use it as a resin molded product from the viewpoint of reduction of driving power due to its weight reduction, and thus the centrifugal fan is constituted by the resin molded product. If it is, it is impossible to integrally mold it from the manufacturing technology,
There is no choice but to make this a divided structure.

Therefore, how to combine the above-mentioned three members constituting the centrifugal fan 50, that is, the hub 51, the shroud 52, and the plurality of blades 53, 53, ... Is a problem. As shown in FIG. 17, the hub 51 and the blades 53, 53, ... Are integrally resin-molded from the standpoint of securing strength performance against air-blowing resistance. Separately, the shroud 52 formed by resin molding is joined and fixed to be integrated.

[0005]

However, the centrifugal fan 50 having such a conventional structure has the following problems.

That is, as shown in FIG.
On the inner peripheral surface 53d side (that is, on the negative pressure surface side of the blade 53), since the inner peripheral surface 53d near the one end 53f of the blade 53 and the inner surface 52a of the shroud 52 are corners, The blade 5 is sucked from the suction port 56.
A part of the air flow flowing into the No. 3 side collides with this corner portion to cause a pressure loss, and also a blowing noise due to the turbulence of the air flow.

Such an air flow collision phenomenon is not limited to the corner portion between the inner peripheral surface 53d of the blade 53 and the inner surface 52a of the shroud 52, and, for example, as shown in FIG. It also occurs on the edge 53a side. That is, the front edge 53a of the blade 53 basically extends in a direction parallel to the axial direction of the hub 51.
In a portion 53a ₁ near the connecting portion to the above, this is bent linearly outward in the radial direction and the tip thereof is joined to the inner surface 52a of the shroud 52 from a substantially orthogonal direction. Therefore, the airflow flowing along the inner surface 52a side of the shroud 52 flows into the neighboring portion 53a _{1 from} a substantially orthogonal direction and collides with this, which is one of the causes of pressure loss and blowing noise. It will be. Also, FIG.
As shown in FIG. 7, the blades 53 are attached to the inner surface 5 of the hub 51.
Since the blades 53 and the hub 51 are erected in a substantially orthogonal state from 1a, the connecting portion between the blades 53 and the hub 51 is also a corner portion. At this corner portion as well as on the shroud 52 side, an air flow collision phenomenon. May occur.

On the other hand, at the connecting portion between the outer peripheral surface 53c of the blade 53 and the inner surface 52a of the shroud 52, the connecting portion is a corner portion, like the inner peripheral surface 53d side. Inflowing air is less likely to flow around the corners, and this is the dead water region S, which is one of the causes of lowering the blowing performance.

In view of the above conventional problems, the present invention has a centrifugal fan capable of realizing high air blowing performance by suppressing the collision of an air flow and the generation of a dead water area as much as possible, and the centrifugal fan. The purpose of the invention is to provide an air conditioner equipped with a fan.

[0010]

In the present invention, the following constitution is adopted as a concrete means for solving such a problem.

In the first invention of the present application, the blades 4 are fixedly arranged in an upright state on the outer peripheral portion of the hub 2 which is rotationally driven, and the shroud 3 having the suction port 5 in the central portion is connected to the hub 2 as described above. In a centrifugal fan in which the blades 4 are sandwiched between and facing each other, a curved surface portion that connects the ridge line portion of the front edge 4a of the blade 4 and the inner surface 3a of the shroud 3 smoothly connects them. It is characterized by being composed of 13.

According to the second invention of the present application, the rotary drive is performed.
When the blades 4 are fixedly arranged in an upright state on the outer peripheral portion of the hub 2,
The shroud 3 with the suction port 5 in the center,
Do not place the blades 4 facing each other with the blades 2 in between.
In the centrifugal fan, the inner surface 3a of the shroud 3
Slide the connecting portion of the blade 4 with the outer peripheral surface 4c on both sides.
In addition to the curved surface portion 11 that connects the crab, the connecting portion between the ridge line portion of the front edge 4a of the blade 4 and the inner surface 3a of the shroud 3 is configured by the curved surface portion 13 that smoothly connects the both , and further the shroud 3 The inner surface 3a of the
The position of the blade 4 is located at a position corresponding to the inner peripheral surface 4d of the blade 4.
It is characterized in that a positioning rib 21 for determining is provided .

The third invention of the present application is the same as the second invention.
In the centrifugal fan according to the above , the radius of curvature or the cross-sectional area of the curved surface portion 11 is set to the innermost peripheral portion 4g and the outermost peripheral portion 4h of the blade 4.
It is characterized in that both are set to be substantially zero.

According to the fourth invention of the present application, a rotary drive is provided.
When the blades 4 are fixedly arranged in an upright state on the outer peripheral portion of the hub 2,
The shroud 3 with the suction port 5 in the center,
Do not place the blades 4 facing each other with the blades 2 in between.
In the centrifugal fan, the inner surface 3a of the shroud 3
Slide the connecting portion of the blade 4 with the inner peripheral surface 4a on both sides.
In addition to the curved surface portion 12 connecting to the crab, the connecting portion between the ridgeline portion of the front edge 4a of the blade 4 and the inner surface 3a of the shroud 3 is configured by the curved surface portion 13 that smoothly connects the both , and further the curved surface portion 12 radius of curvature or cross-sectional area
On both the innermost peripheral portion 4g and the outermost peripheral portion 4h of the blade 4.
And set it so that it is approximately zero.
It corresponds to the inner surface 3a of the louver 3 and the inner peripheral surface 4d of the blade 4.
Positioning ribs 2 for positioning the blades 4 at the positions
1 is provided .

In the fifth invention of the present application, the second, third or
In the centrifugal fan according to the fourth aspect of the present invention, the curved surface portion 1 of the outer peripheral surface 4c of the blade 4 and the inner surface 3a of the shroud 3 is used.
1, the ridge line portion of the front edge 4a of the blade 4 and the curved surface portion 13 of the inner surface 3a of the shroud 3 are integrally formed and subsequently joined to the blade 4 on the hub 2 side. I am trying.

In the sixth invention of the present application, the second, third or
In the centrifugal fan according to the fourth aspect of the present invention, a curved surface portion 1 of the inner peripheral surface 4d of the blade 4 and the inner surface 3a of the shroud 3 is provided.
2 and the curved portion 13 of the ridge line of the front edge 4a of the blade 4 and the inner surface 3a of the shroud 3 are integrally formed and are subsequently joined to the blade 4 on the hub 2 side. I am trying.

In the seventh invention of the present application, the second, third or
In the centrifugal fan according to the fourth invention, the blade 4
The curved surface portions 11 and 12 of the outer peripheral surface 4c and the inner peripheral surface 4d of the shroud 3 and the inner surface 3a of the shroud 3, and the curved surface portion 13 of the ridge line portion of the front edge 4a of the blade 4 and the inner surface 3a of the shroud 3. The shroud 3 is integrally formed with the shroud 3 and is subsequently joined to the blade 4 on the hub 2 side.

In the eighth invention of the present application, the fifth, sixth or
In the centrifugal fan according to the seventh invention, the curved surface portions 11, 12, 1 formed integrally with the shroud 3 are provided.
3 is joined to a portion integrally formed with the hub 2 side excluding the curved surface portions 11, 12, 13 and a rib receiving groove 22 is formed on the curved surface portions 11, 12, 13 side. Positioning ribs 21 are respectively provided on the side of the hub 2 where the components are integrally formed, and the rib receiving grooves 22 and the positioning ribs 21 are fitted in concave and convex.

In the ninth invention of the present application, in the air conditioner constructed by disposing the centrifugal fan 1 and the heat exchanger 32 in the casing 31, the centrifugal fan 1 is the above-mentioned first.
The centrifugal fan according to any one of the first, second, third, fourth, fifth, sixth, seventh or eighth is applied.

[0020]

According to the present invention, the following effects can be obtained by adopting such a configuration.

(A) According to the centrifugal fan of the first invention of the present application, a curved surface portion that smoothly connects the ridge line portion of the front edge 4 a of the blade 4 and the inner surface 3 a of the shroud 3 to these two portions. Since it is composed of 13, the airflow flowing into the connecting portion is connected like the conventional structure in which the connecting portion is linear and is joined to the inner surface 3a side of the shroud 3 in a substantially orthogonal direction. As compared with the case of flowing in from a direction substantially orthogonal to the portion, the air flows into the connecting portion at a smaller inflow angle and is smoothly guided by the curved surface portion 13, so that the air flow can collide with the connecting portion. As much as possible, the pressure loss of the centrifugal fan 1 and the blowing noise are reduced accordingly.

(B) The centrifugal fan according to the second invention of the present application has the following effects.

That is, in the centrifugal fan according to the present invention,
Inner surface 3a of the shroud 3 and outer peripheral surface 4c of the blades 4
Curved surface part 11 that smoothly connects both sides to the connection part with
And the inner surface 3a of the shroud 3 and
The blade 4 at a position corresponding to the inner peripheral surface 4d of the blade 4.
Since the positioning rib 21 for positioning the
Along the inner surface 3a of the shroud 3 and the inner surface 3a
Airflow flowing toward the connecting portion with the outer peripheral surface 4c of the blade 4.
The curved surface 11 guides the flow smoothly.
The connection to the connection as if it were a corner.
The sudden phenomenon is surely prevented, and the pressure of the centrifugal fan 1 is correspondingly increased.
The loss is reduced and the blowing noise is reduced.

Further, since the connecting portion between the ridgeline portion of the front edge 4a of the blade 4 and the inner surface 3a of the shroud 3 is constituted by the curved surface portion 13 that smoothly connects the both, the air flowing into the connecting portion is formed. The flow is compared with a case where the connection portion is linear and flows from the substantially orthogonal direction to the connection portion as in the conventional structure in which the connection portion is joined to the inner surface side of the shroud 3 in the substantially orthogonal direction, By flowing into the connecting portion at a smaller inflow angle and being smoothly guided by the curved surface portion 13, collision of the air flow with the connecting portion is prevented as much as possible, and the pressure loss of the centrifugal fan 1 is reduced accordingly. It is intended to reduce the blowing noise.

(C) The centrifugal fan according to the third aspect of the present invention has the following effects.

That is, in the centrifugal fan according to the present invention,
The radius of curvature or the cross-sectional area of the curved surface portion 11 is defined as
It becomes approximately zero in both the innermost peripheral portion 4g and the outermost peripheral portion 4h.
Since it is set as follows,
Collision of air flow at the connecting part is avoided, and it is described in (a) above.
In addition to the effect of
In the innermost peripheral portion 4g of the curved surface portion 11, the curved surface portion 11 is formed.
Since the radius of curvature or the cross-sectional area of the
The transition of the air flow flowing from the g side to the curved surface 11 side is more
It becomes smooth and the air flow guiding function of the curved surface portion 11 becomes
If it is even better, the outermost circumference of the curved surface portion 11
In the portion 4h, the radius of curvature or the cross-sectional area of the curved surface portion 11 is
It is blown out through the curved surface portion 11 because it is set to almost zero.
The width of the air flow that is generated, that is, the width of the wake of the blade 4 is reduced,
Turbulence is suppressed and blast noise can be generated due to turbulence in the wake.
Will be suppressed as much as possible.

Further, since the connecting portion between the ridgeline portion of the front edge 4a of the blade 4 and the inner surface 3a of the shroud 3 is formed by the curved surface portion 13 that smoothly connects the both, air flowing into the connecting portion is formed. The flow is compared with a case where the connection portion is linear and flows from the substantially orthogonal direction to the connection portion as in the conventional structure in which the connection portion is joined to the inner surface side of the shroud 3 in the substantially orthogonal direction, By flowing into the connecting portion at a smaller inflow angle and being smoothly guided by the curved surface portion 13, collision of the air flow with the connecting portion is prevented as much as possible, and the pressure loss of the centrifugal fan 1 is reduced accordingly. It is intended to reduce the blowing noise.

(D) The centrifugal fan according to the fourth invention of the present application has the following effects.

That is, in the centrifugal fan according to the present invention,
The inner surface 3a of the shroud 3 and the inner peripheral surface 4d of the blade 4
Curved surface part 12 that smoothly connects these two sides to the connection part with
And the radius of curvature of the curved surface portion 12 or
The area of the blade 4 is defined by the innermost peripheral portion 4g and the outermost peripheral portion 4h.
On the other hand, it is set so that
It corresponds to the inner surface 3a of the louver 3 and the inner peripheral surface 4d of the blade 4.
Positioning ribs 2 for positioning the blades 4 at the positions
1 is provided, the inner surface 3a of the shroud 3 is
At the connecting portion between the inner surface 3a and the outer peripheral surface 4c of the blade 4,
The air flow that flows in toward the air flow is generated by the curved surface portion 12.
If this is smoothly guided and the connection is a corner
The collision phenomenon to the connection part is surely prevented, and the centrifugal flap is
In addition to reducing the pressure loss of the fan and the noise of the blower,
In the innermost peripheral portion 4g of the curved surface portion 12, the curved surface
By setting the radius of curvature or the cross-sectional area of the portion 12 to be substantially zero, the innermost
Transition of airflow flowing from the peripheral portion 4g side to the curved surface portion 12 side
Is smoother and the curved surface 12 guides the air flow.
If the action is further improved, the curved surface portion 12
At the outermost peripheral portion 4h, the radius of curvature of the curved surface portion 12 or disconnection
Since the area is almost zero,
The width of the air flow blown out, that is, the wake of the blade 4 is small.
The turbulence is suppressed and the blast noise is generated due to the turbulence in the wake.
Life is suppressed as much as possible.

Further, since the connecting portion between the ridgeline portion of the front edge 4a of the blade 4 and the inner surface 3a of the shroud 3 is constituted by the curved surface portion 13 which smoothly connects the both, air flowing into the connecting portion is formed. The flow is compared with a case where the connection portion is linear and flows from the substantially orthogonal direction to the connection portion as in the conventional structure in which the connection portion is joined to the inner surface side of the shroud 3 in the substantially orthogonal direction, By flowing into the connecting portion at a smaller inflow angle and being smoothly guided by the curved surface portion 13, collision of the air flow with the connecting portion is prevented as much as possible, and the pressure loss of the centrifugal fan 1 is reduced accordingly. It is intended to reduce the blowing noise.

(E) According to the centrifugal fan of the fifth invention of the present application, in the centrifugal fan of the second, third or fourth invention, the outer peripheral surface 4c of the blade 4 and the inner surface of the shroud 3 are provided. 3a, the curved surface portion 11 of the front edge 4a of the blade 4 and the curved surface portion 13 of the inner surface 3a of the shroud 3 are integrally formed, and afterwards the hub 2 is formed.
Since it is joined to the above-mentioned blade 4 on the side,
In addition to the effects described in (b), (c) or (d) , the following unique effects can be obtained.

That is, for example, on the blade 4 side integrally formed with the hub 2, the curved surface portions 11,
If 13 is integrally formed, the shape of this resin molded product becomes complicated and its molding becomes difficult.
By integrally forming the shroud 3 on the side of the shroud 3 which has a simple shape, the shroud 3 can be easily manufactured, and the manufacturing cost can be reduced accordingly.

(F) According to the centrifugal fan of the sixth invention of the present application, in the centrifugal fan of the second, third or fourth invention, the inner peripheral surface 4d of the blade 4 and the shroud 3 are The curved surface portion 12 of the inner surface 3a, the ridge line portion of the front edge 4a of the blade 4 and the curved surface portion 13 of the inner surface 3a of the shroud 3 are integrally formed, and afterwards, the blade 4 on the hub 2 side. Since it is designed to be joined to
In addition to the effects described in (b), (c) or (d) , the following unique effects can be obtained.

That is, for example, on the blade 4 side integrally formed with the hub 2, the curved surface portions 12,
If 13 is integrally formed, the shape of this resin molded product becomes complicated and its molding becomes difficult.
By integrally forming the shroud 3 on the side of the shroud 3 which has a simple shape, the shroud 3 can be easily manufactured, and the manufacturing cost can be reduced accordingly.

(G) According to the centrifugal fan of the seventh invention of the present application, in the centrifugal fan of the second, third or fourth invention, the outer peripheral surface 4c and the inner peripheral surface 4d of the blade 4 are A curved surface portion 11 with the inner surface 3a of the shroud 3,
12, a ridge line portion of the front edge 4a of the blade 4 and a curved surface portion 13 of the inner surface 3a of the shroud 3 are integrally formed with the shroud 3, and subsequently joined to the blade 4 on the hub 2 side. Therefore, the above (b), (c) or
In addition to the effect described in (d) , the following unique effect can be obtained.

That is, for example, on the side of the blade 4 formed integrally with the hub 2, the curved surface portions 11,
When 12 and 13 are integrally formed, the shape of this resin molded product becomes complicated and its molding becomes difficult.
By integrally forming 1, 12, 13 on the side of the shroud 3 having a simple shape, the shroud 3 can be easily manufactured, and the manufacturing cost can be reduced accordingly.

(H) According to the centrifugal fan of the eighth invention of the present application, in the centrifugal fan of the fifth, sixth or seventh invention, the curved surface portion integrally formed with the shroud 3 is used. 11, 12, 13 to the curved surface portion 11,
The curved surface portions 11, 12, 13 are configured to be joined together with the integral constituent portion with the hub 2 side except 12 and 13.
Since the rib receiving groove 22 is provided on the side, and the positioning rib 21 is provided on the side of the integrally formed portion on the side of the hub 2, the rib receiving groove 22 and the positioning rib 21 are fitted in concave and convex. When the curved surface portions 11, 12, 13 side integrally formed with the shroud 3 and the integral constituent portion on the hub 2 side are joined, positioning is easily performed by the concave and convex fitting, and in the joined state, For example, as compared with the case of joining flat surfaces, the joining strength is further improved.

(B) According to the air conditioner of the ninth invention of the present application, in the air conditioner configured by disposing the centrifugal fan 1 and the heat exchanger 32 in the casing 31,
As the centrifugal fan 1, the first, second, third and third
Since the centrifugal fan according to the fourth, fifth, sixth, seventh or eighth invention is applied, the centrifugal fan has the characteristics of low pressure loss and low blowing noise.
It is possible to provide an air conditioner having both high air conditioning performance and quietness.

[0039]

BEST MODE FOR CARRYING OUT THE INVENTION A centrifugal fan and an air conditioner according to the present invention will be specifically described below based on preferred embodiments.

A: Centrifugal fan Five embodiments are shown below as embodiments of the centrifugal fan according to the present invention. A-1: First Embodiment FIGS. 1 and 2 show a first embodiment of a centrifugal fan according to the present invention. The centrifugal fan 1 according to the first embodiment is provided with a hub 2 to which a motor 7 is connected in the central portion thereof and which is driven to rotate by the motor 7, and a suction port 5 in the central portion thereof, A plurality of shrouds 3 that are coaxially opposed to each other at a predetermined interval, and a plurality of shrouds that have a curved plate shape and are arranged in an upright state across the inner surface 2a of the hub 2 and the inner surface 3a of the shroud 3. , And blades 4, 4 ,. All of the above-mentioned members constituting the centrifugal fan 1 are molded from a resin material, and the molding structure thereof is, as shown in FIG. 3, the blades 4, 4 ,. Is integrally resin-molded together with the hub 2, the shroud 3 is resin-molded by itself, and the centrifugal fan 1 is obtained by subsequently joining the both.

Further, as shown in FIG. 3, the integrally molded product of the hub 2 and the blades 4, 4, ... Is joined to the molded product of the shroud 3 only on the inner surface 3a side of the shroud 3 in advance. The positioning rib 21 is integrally molded, and the tip 4f of the blade 4 integrally molded with the hub 2 is abutted against the inner surface of the shroud 3 so as to be aligned with the positioning rib 21, and the both are bonded. It is fixed by joining and integrated.

By the way, in the centrifugal fan 1 in this embodiment, by applying the present gun onset bright, the outer peripheral surface 4 of the blade 4
The connecting portion between c and the inner surface 3a of the shroud 3 is formed into a curved surface portion 11 which is a curved surface smoothly connecting the outer peripheral surface 4c of the blade 4 to the inner surface 3a of the shroud 3. The curved surface portion 11, as shown in FIG. 4, are formed in a portion of the over the outermost periphery 4h from the innermost portion 4g of the connecting portion, in this case, in those of this embodiment, the gun onset The shape of the curved surface portion 11 is made larger by applying the light, and the curvature radius of the surface of the curved surface portion 11 or the cross-sectional area of the curved surface portion 11 is large at the intermediate portion between the innermost peripheral portion 4g and the outermost peripheral portion 4h. It is set to be substantially zero in both the inner peripheral portion 4g and the outermost peripheral portion 4h.

When the centrifugal fan 1 thus constructed is rotationally driven by the motor 7, the air flow sucked into the fan from the suction port 5 is blown by the blades 4, 4 ,. In response, the air is blown outward in the radial direction from the air outlet 6 formed between the outer peripheral portions of the hub 2 and the shroud 3.

In this case, in the centrifugal fan 1 of this embodiment, the connecting portion between the inner surface 3a of the shroud 3 and the outer peripheral surface 4c of the blade 4 is formed by the curved surface portion 11 that smoothly connects both surfaces. The curved surface 11 smoothly guides the airflow flowing along the inner surface 3a of the shroud 3 toward the connecting portion between the inner surface 3a and the outer peripheral surface 4c of the blade 4. For this reason, it is possible to prevent the air flow from colliding with the connection portion as much as possible, for example, when the connection portion is a corner portion, and as a result, in the centrifugal fan 1, the air flow is prevented. Since the pressure loss is reduced and high static pressure is obtained as much as there is no collision, the blast noise is suppressed because the turbulence of the air flow caused by the collision is also prevented, and higher ventilation performance is realized. It is something.

Further, in this case, in the centrifugal fan 1 of this embodiment, the radius of curvature or the cross-sectional area of the curved surface portion 11 is substantially zero in both the innermost peripheral portion 4g and the outermost peripheral portion 4h of the blade 4. Therefore, in the innermost peripheral portion of the curved surface portion 11, the transition of the air flow flowing from the innermost peripheral portion 4g side to the curved surface portion 11 side becomes smoother, and the air by the curved surface portion 11 becomes smoother. If the flow guiding function is further improved, a higher static pressure is secured. Further, on the outermost peripheral portion 4h side of the curved surface portion 11, since the width of the airflow blown through the curved surface portion 11, that is, the wake of the blade 4 is reduced, and its turbulence is suppressed, The generation of blower noise due to turbulence in the wake is suppressed as much as possible, and the centrifugal fan 1
The reduction of the blowing noise as a whole is further promoted.

FIG. 15 shows a comparison of the blowing noise and static pressure of the centrifugal fan 1 with those of the centrifugal fan having the conventional structure. Here, "air volume - blowing noise characteristic diagram" and - in each of the "air volume static pressure characteristic diagram", code L ₁
Reference characters L ₂ and L ₂ indicate the characteristics of the centrifugal fan 1 according to this embodiment, and reference characters L ₁₀ and L ₂₀ indicate the characteristics of the centrifugal fan having the conventional structure. From FIG. 15, it can be seen that the centrifugal fan 1 of this embodiment has characteristics that the blowing noise is low and the static pressure is high as compared with the centrifugal fan having the conventional structure. Further, such characteristics can be similarly obtained in the centrifugal fans of the following second to fifth embodiments.

A-2: Second Embodiment FIGS. 5 and 6 show a main part of a centrifugal fan 1 according to a second embodiment of the present invention (FIG. 5 shows II in FIG. 1).
-Corresponding to section II). The centrifugal fan 1 according to the second embodiment, like the centrifugal fan 1 according to the first embodiment, spans between a hub 2 and a shroud 3 that are coaxially opposed to each other. , The blades 4, 4, ... Are arranged, and the molding structure thereof is the same as in the centrifugal fan 1 of the first embodiment, the hub 2 and the blades 4, 4 ,. The structure is such that the integrally molded product and the molded product having only the shroud 3 are subsequently joined together.

The centrifugal fan 1 according to the second embodiment is the centrifugal fan 1 according to the first embodiment.
There are the following two structural differences. In other words, this in such a centrifugal fan 1 in the second embodiment, first, first, by applying the present gun onset Ming, of ridge portions of the shroud side end portion 4a ₁ of the front edge 4a of the blade 4, The vicinity of the connection portion to the inner surface 3a of the shroud 3 is a curved surface portion 13 which is a curved surface smoothly connected from the ridge portion to the inner surface 3a of the shroud 3. Second, the book
By applying the gun onset bright, as shown in FIGS. 5 to 7, the connecting portion between the inner surface 3a of the inner peripheral surface 4d and the shroud 3 of the distal end portion 4f toward the blade 4, both the faces 4d, the 3a A smoothly connected curved surface is used as the curved surface portion 12, and the shape of the curved surface portion 12 is such that the radius of curvature of the surface of the curved surface portion 12 or the cross-sectional area of the curved surface portion 12 is the innermost peripheral portion 4g of the connection portion. This is a point set to be substantially zero in both of the outermost peripheral portions 4h.

In the centrifugal fan 1 according to the second embodiment configured as described above, the front edge 4 of the blade 4 is
Since the connecting portion between the ridge line portion at the shroud-side end portion 4a ₁ of a and the inner surface 3a of the shroud 3 is formed by the curved surface portion 13 that smoothly connects the both, the air flow flowing into the connecting portion is It is smaller than in the case where the connection portion is linear and flows in the connection portion from the substantially orthogonal direction as in the conventional structure which is joined to the inner surface 3a side of the shroud 3 in the substantially orthogonal direction. It will flow into the connection at an inflow angle. As a result, the air flow is curved as described above.
To more smoothly flow into the connection portion, and the collision of the air flow with the connection portion is prevented as much as possible, so that the pressure loss of the centrifugal fan 1 and the blowing noise are reduced.

Further, in the centrifugal fan 1 according to the second embodiment, the inner surface 3a of the shroud 3 and the blades 4 are provided.
Since the connecting portion with the inner peripheral surface 4d is formed by the curved surface portion 12 that smoothly connects the both surfaces, the inner surface 3a and the outer peripheral surface 4c of the blade 4 along the inner surface 3a of the shroud 3.
The curved surface portion 12 smoothly guides the flow of the airflow flowing toward the connection portion with the, and the collision phenomenon to the connection portion is reliably prevented as in the case where the connection portion is a corner portion, The pressure loss of the centrifugal fan 1 and the blowing noise can be reduced.

Further, in this case, since the radius of curvature or the cross-sectional area of the curved surface portion 12 is set to be substantially zero in both the innermost peripheral portion 4g and the outermost peripheral portion 4h of the blade 4, At the innermost peripheral portion of the curved surface portion 12, the innermost peripheral portion 4
The transition of the air flow flowing from the g side to the curved surface portion 12 side becomes smoother, and the guiding function of the air flow by the curved surface portion 12 is further improved, and at the outermost peripheral portion 4h of the curved surface portion 12, The width of the air flow blown out through the curved surface portion 12, that is, the width of the wake of the blades 4 is reduced, and its turbulence is suppressed, so that the generation of blowing noise due to the turbulence of the wake is suppressed as much as possible. .

A-3: Third Embodiment FIG. 8 shows a centrifugal fan 1 according to a third embodiment of the present invention. The basic configuration of the centrifugal fan 1, that is, the configuration in which the blades 4, 4, ... Are disposed between the hub 2 and the shroud 3 that are coaxially opposed to each other, has the above-described first configuration.
It is similar to the centrifugal fan 1 according to the embodiment of the present invention, and on the premise of such a basic configuration, the connecting portions between the inner surface 3a of the shroud 3 and the outer peripheral surface 4c and the inner peripheral surface 4d of the blade 4 are smoothed on both sides. Curved surface parts 11 and 12 connected to
The curved radii or cross-sectional areas of the curved surface portions 11 and 12 are substantially zero in both the innermost peripheral portion 4g and the outermost peripheral portion 4h of the blade 4. It is set so that

In the centrifugal fan 1 according to the third embodiment having such a configuration, the inner surface 3a of the shroud 3 is described.
The airflows flowing along the inner surface 3a of the shroud 3 and the outer peripheral surface 4c of the vane 4 and the connecting portion of the inner surface 3a of the shroud 3 and the inner peripheral surface 4d of the vane 4 along , The flow is smoothly guided by the curved surfaces 11 and 12, and the collision phenomenon to the respective connecting portions is reliably prevented as in the case where the respective connecting portions are corners. The pressure loss and the blowing noise are reduced.

A-4: Fourth Embodiment FIGS. 9 and 10 show a centrifugal fan 1 according to a fourth embodiment of the present invention. Centrifugal fan 1 according to the fourth embodiment, which has been constructed by applying the present gun onset Ming, three members constituting the centrifugal fan 1, that is, the hub 2 and the shroud 3 and a plurality Blades 4,
4, ... Are both resin-molded products, and these three members are a resin-molded product of the hub 2 and the blades 4, 4, ... And a resin-molded product of the shroud 3 only. The centrifugal fan 1 of each of the above-described embodiments having a two-part structure
Although the basic molding structure in 1) follows this, the details of the molding structure are different from these.

That is, in each of the above embodiments,
The tip portion 4f of the blade 4 and the inner surface 3a of the shroud 3
Curved surface portions 11 and 12 at the connection portion with and the blade 4
Of the front edge 4a of the shroud and the curved surface portion 1 at the connecting portion between the ridge portion of the shroud-side end portion 4a ₁ and the inner surface 3a of the shroud 3
3 is formed on the side of the integrally molded product of the vane 4 and the hub 2, both of them are integrally molded on the side of the shroud 3 in the fourth embodiment. ing. Further, in this embodiment, each curved surface portion 1 described above is used.
1 and 12, the radius of curvature or the cross-sectional area thereof is set to be substantially zero in both the innermost peripheral portion 4g and the outermost peripheral portion 4h of the blade 4, as in the above-described embodiments. It is the same.

Here, for convenience of explanation, the blade 4 is
Of the curved surface portions 11, 12 and 13 integrally formed on the shroud 3 side, the curved surface portions 1 and 12 are attached to the attached portion 4A and the curved surface portions 1 are
The main part 4B is an integral part of the hub 2 except for the parts 1, 12, and 13.

Further, in the centrifugal fan 1, as shown in FIG. 10, in this embodiment, the accessory portion 4A is abutted on the main body portion 4B of the blade 4 and is joined and fixed so that each of the above-mentioned components is removed. It is configured by integrating the members 2, 3 and 4, but in this case, the main body portion 4B has a positioning rib 21 formed of a convex strip, and the end portion of the auxiliary portion 4A has a concave groove. Each rib receiving groove 22 is provided.

In the centrifugal fan 1 according to the fourth embodiment having such a configuration, first, the outer peripheral surface 4c of the blade 4 is first described.
Since the inner peripheral surface 4d and the inner peripheral surface 4d are smoothly connected to the inner surface 3a of the shroud 3 by the curved surface portions 11 and 12, respectively, the inner surface 3a is formed along the inner surface 3a of the shroud 3.
The airflow flowing toward the connecting portion between the blade 4 and the outer peripheral surface 4c of the blade 4 is smoothly guided by the curved surface portion 12, and the airflow to the connecting portion is the same as when the connecting portion is a corner portion. The collision phenomenon is reliably prevented, and the pressure loss of the centrifugal fan and the blowing noise are reduced. Also in this case,
Since the radius of curvature or the cross-sectional area of each of the curved surface portions 11 and 12 is set to be substantially zero in both the innermost peripheral portion 4g and the outermost peripheral portion 4h of the blade 4, In the inner peripheral part, the transition of the airflow flowing from the innermost peripheral part 4g side to the curved surface part 12 side becomes smoother, and the guiding function of the airflow by the curved surface part 12 is further improved. In the outermost peripheral portion 4h of 12, the width of the air flow blown out through the curved surface portion 12, that is, the wake of the blade 4 is reduced, and its turbulence is suppressed, so that the blast noise due to the turbulence of the wake can be generated. It will be suppressed as much as possible.

The connecting portion between the ridgeline portion of the front edge 4a of the blade 4 and the inner surface 3a of the shroud 3 is the curved surface portion 13
Since the airflows flowing into the connection portions are smoothly connected to each other by the conventional structure in which the connection portions are linear and are joined to the inner surface 3a side of the shroud 3 in a substantially orthogonal direction. Compared with the case of flowing in from the direction substantially orthogonal to the connecting portion, the air flows into the connecting portion at a smaller inflow angle and is smoothly guided by the curved surface portion 13 so that the air flow collides with the connecting portion. Is prevented as much as possible,
Therefore, the pressure loss of the centrifugal fan 1 and the blowing noise can be reduced.

Further, when the hub 2 side and the shroud 3 side are adhesively joined, the positioning rib 21 is fitted into the rib receiving groove 22 so that the positioning of both of them can be performed easily and quickly. The cost can be reduced, and the joining of the both is performed by the positioning rib 2
By performing the concave-convex fitting between the rib 1 and the rib receiving groove 22, the joining strength can be further enhanced, as compared with the case of the abutting joining structure of flat surfaces as in the above-described embodiments. The reliability in use of the centrifugal fan 1 is further enhanced.

Further, since the attachment portion 4A of the blade 4 is formed integrally with the shroud 3, for example, the attachment portion 4A is formed integrally with the main body portion 4B on the hub 2 side. Compared with the case, the structure on the hub 2 side is simplified and can be easily molded, and the manufacturing cost can be reduced accordingly.

A-5: Fifth Embodiment FIGS. 11 to 13 show a centrifugal fan 1 according to a fifth embodiment of the present invention. The centrifugal fan 1 of this embodiment has the same basic configuration as the centrifugal fan of each of the above-described embodiments, and is different from these in the connecting portion between the blade 4 and the shroud 3 as in each of the above-described embodiments. Rather than providing the curved surface portion, curved surface portions 14 and 15 are provided at the connecting portions between the inner surface 2a of the hub 2 and the outer peripheral surface 4c and the inner peripheral surface 4d of the blade 4 formed integrally with the inner surface 2a. It is a point.

With such a structure, the airflow flowing from the suction port 5 toward the hub 2 is smoothly guided by the curved surface portions 14 and 15, and the connecting portion is a corner portion. As in some cases, the collision phenomenon to the connecting portion is reliably prevented, and the pressure loss and the blowing noise in the centrifugal fan 1 are reduced accordingly.

In this embodiment, the hub 2 described above is used.
Although the curved portions 14 and 15 are provided only on the side, in another embodiment, the configuration in this embodiment, that is,
Needless to say, the configuration in which the curved surface portions 14 and 15 are provided only on the hub 2 side may be added to the configurations of the above-described embodiments.

B: Air Conditioner FIG. 14 shows an air conditioner Z having the centrifugal fan 1 according to the first embodiment as an example of an air conditioner having the centrifugal fan according to the present invention. Is shown. The air conditioner Z is an indoor unit of a separate type air conditioner that is embedded in the ceiling 35, and the centrifugal fan 1 is provided at a substantially central portion of the casing 31 with the suction port 5 thereof.
Is arranged downward, and the heat exchanger 32 is arranged on the outer peripheral side of the centrifugal fan 1 so as to face the outlet 6.
It is configured by arranging. Then, by operating the centrifugal fan 1, the indoor air sucked from the suction port 33 provided in the central portion of the lower surface 31a of the casing 31 is heat-exchanged in the heat exchanger 32 into hot air or cold air,
The air is blown out into the room from the air outlet 34 provided on the outer peripheral portion of the lower surface 31a.

In this air conditioner Z, the centrifugal fan 1 according to the embodiments of the present invention is provided as a centrifugal fan, so that the characteristics of the centrifugal fan 1 as described in each of the above embodiments, that is, the pressure loss. It has both high air conditioning performance and quietness based on the characteristics of low air flow and low blowing noise.

Of course, the centrifugal fan 1 according to each of the above-described embodiments can be appropriately selected and applied as the centrifugal fan.

[Brief description of drawings]

FIG. 1 is a plan view of a centrifugal fan according to a first embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a main part of II-II in FIG.

FIG. 3 is an enlarged sectional view taken along the line III-III in FIG.

FIG. 4 is a perspective view of a portion IV in FIG.

FIG. 5 is a sectional view of essential parts of a centrifugal fan according to a second embodiment of the present invention.

6 is a VI-VI enlarged cross-sectional view of FIG.

7 is a perspective view of a portion VII of FIG.

FIG. 8 is a cross-sectional view of essential parts of a centrifugal fan according to a third embodiment of the present invention.

FIG. 9 is a sectional view of essential parts of a centrifugal fan according to a fourth embodiment of the present invention.

10 is an enlarged cross-sectional view taken along line XX of FIG.

FIG. 11 is a sectional view of essential parts of a centrifugal fan according to a fifth embodiment of the present invention.

12 is an enlarged sectional view taken along line XII-XII of FIG.

13 is a perspective view of a portion XIII in FIG.

FIG. 14 is a cross-sectional view of an air conditioner according to the present invention.

FIG. 15 is a characteristic diagram of “air volume-blowing noise / static pressure” of the centrifugal fan.

FIG. 16 is a sectional view of a main part of a conventional centrifugal fan.

17 is an enlarged sectional view taken along line XVII-XVII in FIG.

[Explanation of symbols]

1 is a centrifugal fan, 2 is a hub, 3 is a shroud, 4 is a blade, 5 is an inlet, 6 is an outlet, 7 is a motor, 11 to 11
5 is a curved surface portion, 31 is a casing, 32 is a heat exchanger, 33
Is an inlet, 34 is an outlet, and 35 is a ceiling.

─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-60-88898 (JP, A) JP-A-7-109997 (JP, A) JP-A-5-312191 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) F04D 29/28 F04D 29/30

Claims (9)

(57) [Claims] 1. A hub (2), which is rotationally driven, has blades (4) fixedly installed on the outer periphery of the hub (2), and a shroud (3) having a suction port (5) in the center thereof is provided in the hub. A centrifugal fan arranged so as to face each other with the blade (4) sandwiched between the blade (4) and the ridge line portion of the front edge (4a) of the blade (4) and the inner surface of the shroud (3). A centrifugal fan, characterized in that a connecting portion with (3a) is constituted by a curved surface portion (13) that smoothly connects the both. 2. A wing is provided on an outer peripheral portion of a hub (2) which is rotationally driven.
The root (4) is fixedly installed in an upright state, and at the center
The shroud (3) provided with the suction port (5) is attached to the hub.
Arranged facing each other with the blade (4) sandwiched between (2)
A centrifugal fan comprising: an inner surface (3a) of the shroud (3) and the blades (4).
The connecting part with the outer peripheral surface (4c) smoothly connects both surfaces.
The shroud (3) and the ridge line portion of the front edge (4a) of the blade (4) are constituted by the curved surface portion (11) which is slanted.
Connection between the inner surface (3a) of is a curved surface portion that connects smoothly the both of them (13), further and above the inner surface (3a) of the shroud (3)
The blade is located at a position corresponding to the inner peripheral surface (4d) of the blade (4).
A positioning rib (21) for positioning (4) is provided.
Centrifugal fan characterized in that it is. 3. The curvature radius or cross-sectional area of the curved surface portion (11) according to claim 2, wherein the radius of curvature or the cross-sectional area of the blade (4) is substantially zero at both the innermost peripheral portion (4g) and the outermost peripheral portion (4h). Centrifugal fan characterized by being set to be. 4. A wing is provided on an outer peripheral portion of a hub (2) which is rotationally driven.
The root (4) is fixedly installed in an upright state, and at the center
The shroud (3) provided with the suction port (5) is attached to the hub.
Arranged facing each other with the blade (4) sandwiched between (2)
A centrifugal fan comprising: an inner surface (3a) of the shroud (3) and the blades (4).
The inner peripheral surface (4a) of the joint smoothly connects both surfaces.
The shroud (3) and the ridge line portion of the front edge (4a) of the blade (4) , which is composed of the curved surface portion (12 )
The connecting portion with the inner surface (3a) of the curved surface portion (13) smoothly connects the both , and further the radius of curvature or the cross-sectional area of the curved surface portion (12) is
Of the innermost peripheral portion (4g) and the outermost peripheral portion (4h) of the blade (4)
Both are set to be approximately zero, and
The inner surface (3a) of the shroud (3) and the blade
The blade is provided at a position corresponding to the inner peripheral surface (4d) of (4).
A positioning rib (21) for positioning (4) is provided.
Centrifugal fan characterized in that it is. 5. The curved surface portion (11) of the outer peripheral surface (4c) of the blade (4) and the inner surface (3a) of the shroud (3) according to claim 2, 3 or 4 , and the blade (4). Ridge of the front edge (4a) and the shroud (3)
Centrifugal fan characterized in that the inner surface (3a) and the curved surface portion (13) are integrally formed and are subsequently joined to the blades (4) on the hub (2) side. 6. The curved surface portion (12) of the inner peripheral surface (4d) of the blade (4) and the inner surface (3a) of the shroud (3) according to claim 2, 3 or 4 , and the blade (4). ) The ridge of the front edge (4a) and the shroud (3)
Centrifugal fan characterized in that the inner surface (3a) and the curved surface portion (13) are integrally formed and are subsequently joined to the blades (4) on the hub (2) side. 7. The curved surface portion (1) according to claim 2, 3 or 4, wherein an outer peripheral surface (4c) and an inner peripheral surface (4d) of the blade (4) and an inner surface (3a) of the shroud (3).
1) and 12), the ridgeline part of the front edge (4a) of the blade (4) and the curved surface part (13) of the inner surface (3a) of the shroud (3) are integrated with the shroud (3). Centrifugal fan, characterized in that it is formed integrally and is subsequently joined to the blades (4) on the hub (2) side. 8. The curved surface portion (11), (12), (13) integrally formed with the shroud (3) according to claim 5, 6 or 7 ,
Ribs are formed on the curved surface portions (11), (12) and (13) side, which are joined together with the integral portion of the hub (2) side except for (12) and (13). Receiving groove (2
2), positioning ribs (21) are respectively provided on the integrated component side of the hub (2) side, and the rib receiving groove (22) and the positioning rib (21) are fitted in concave and convex. Characteristic centrifugal fan. 9. An air conditioner configured by arranging a centrifugal fan (1) and a heat exchanger (32) in a casing (31), wherein the centrifugal fan (1) comprises : 2, 3, 4,
An air conditioner to which the centrifugal fan according to 5, 6, 7 or 8 is applied.