JP2016132991A - Blower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blower which enables reduction of separation flow occurring at a front edge of each blade to reduce turbulence noise.SOLUTION: A blower includes: a centrifugal fan 30 rotationally driven by a fan motor 34 and including a main plate 31, a shroud 36 which is disposed facing the main plate 31, and blades 39 disposed between the main plate 31 and the shroud 36; and an orifice 40 which is disposed at the air inflow side of the shroud 36 so as to be spaced away from the shroud 36. Guide fins 44 are provided on an outer peripheral surface of the orifice 40 so as to be spaced a predetermined distance away from each other in a circumferential direction. A shroud 36 side end part of each guide fin 44 is disposed inclining in an opposite direction of a rotation direction of the centrifugal fan 30.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an air blower, and more particularly to an air blower provided with a centrifugal fan and an orifice widely used in an indoor unit of an air conditioner.

2. Description of the Related Art Conventionally, for example, an air blower that is attached to an indoor unit of an air conditioner and sucks indoor air and returns the air after heat exchange to the room is often used.
As this type of blower, conventionally, for example, an impeller including a shroud and a plurality of blades, and a bell mouth disposed between the shroud and the air suction port, on the outer peripheral surface of the bell mouth, A technique is disclosed in which a plurality of wall portions are provided that are arranged at predetermined intervals along the circumferential direction and are erected from the outer peripheral surface (see, for example, Patent Document 1).

Japanese Patent No. 5195983

However, in the conventional configuration, by operating the air blowing device, the sucked air is blown in the centrifugal direction by the blades, but a part of the air blown out from the impeller is accompanied by a swirling component, It re-enters from the gap between the shroud and bellmouth.
In this case, in the prior art, since the bell mouth is provided with a plurality of wall portions extending substantially parallel to the rotation axis of the blade, the air re-entering the impeller collides with the wall portion. Thus, the blade is forced in the direction of the rotation axis of the blade. For this reason, the re-inflowing air collides with the rotating blades to generate a separation flow, resulting in an increase in turbulent noise.

  The present invention has been made in view of the above-described points, and an object of the present invention is to provide a blower device that can reduce the separation flow generated at the leading edge of the blade and reduce turbulent noise.

In order to achieve the above object, a blower of the present invention is driven by a fan motor to rotate, and includes a main plate, a shroud disposed to face the main plate, and a plurality of blades disposed between the main plate and the shroud. A centrifugal fan, and an orifice disposed at a predetermined gap between the shroud and the air inflow side of the shroud, and a plurality of guide fins are provided on the outer peripheral surface of the orifice at a predetermined interval in the circumferential direction. The shroud side end portion of the guide fin is arranged to be inclined in the direction opposite to the rotation direction of the centrifugal fan.
According to this configuration, the plurality of guide fins that are inclined so that the upper end portion is located in the direction opposite to the rotation direction of the centrifugal fan are formed on the outer peripheral surface of the orifice. Since it is guided to incline in the direction opposite to the rotation direction of the fan and re-enters the centrifugal fan, the inflow angle of the circulation flow becomes an angle close to the inlet angle in the height direction of the blade, A circulating flow can be introduced in a direction along the surface of the wing.

  Further, the present invention is characterized in that, in the above configuration, the guide fin is such that the outermost end of the shroud side end is located radially outward from the suction side opening of the shroud.

  Further, the present invention is characterized in that, in the above configuration, the guide fin has an outermost end portion on the suction side opening side of the orifice located radially outward from the suction side opening of the orifice.

  According to the blower of the present invention, by forming the guide fins in the orifice, it is possible to increase the resistance that the circulating flow receives at the time of circulation, to reduce the circulating flow, and to circulate the circulating flow along the surface of the blade. Since it can be made to flow in the direction, the separation flow generated at the front edge of the blade can be reduced, and the turbulent noise caused by the circulation flow can be significantly reduced. Further, by reducing the turbulent noise, the air blowing performance of the centrifugal fan can be improved. As a result, the centrifugal fan can be made small, so that weight reduction and cost reduction can be achieved.

It is a longitudinal section showing a 1st embodiment of an indoor unit to which a blower concerning the present invention is applied. It is a perspective view of the air blower in 1st Embodiment. It is sectional drawing of the air blower in 1st Embodiment. It is a perspective view of the air blower in 2nd Embodiment. It is sectional drawing of the air blower in 2nd Embodiment.

Hereinafter, an embodiment of a blower according to the present invention will be described with reference to the drawings.
FIG. 1 is a side cross-sectional view of a ceiling-embedded indoor unit to which a blower according to a first embodiment of the present invention is applied.
In the present embodiment, as shown in FIG. 1, the ceiling-embedded indoor unit 10 is installed in a ceiling space 13 between a ceiling 11 of a building and a ceiling plate 12 installed below the ceiling 11. Is.
The ceiling-embedded indoor unit 10 includes an air conditioner main body 14 formed in a box shape with an open lower surface, as shown in FIG. It is installed in a manner that can be suspended from. Inside the air conditioner main body 14, a heat insulating member 16 made of polystyrene foam is disposed in contact with the inner surface of the side plate 17 of the air conditioner main body 14 to prevent condensation on the side plate 17.

  A blower device 20 is attached to the lower surface of the upper plate of the air conditioner main body 14, and in a plan view so as to surround the side of the blower device 20 between the blower device 20 and the heat insulating member 16. A heat exchanger 18 bent in a substantially square shape is disposed.

The heat exchanger 18 functions as a refrigerant evaporator during the cooling operation, and functions as a refrigerant radiator during the heating operation. The heat exchanger 18 exchanges heat between the indoor air sucked into the air conditioner main body 14 and the refrigerant, cools the air in the air-conditioned room during the cooling operation, and heats the indoor air during the heating operation. It is configured to be able to.
Further, a drain pan 19 is disposed below the heat exchanger 18 so as to correspond to the lower surface of the heat exchanger 18. The drain pan 19 is for receiving drain water generated in the heat exchanger 18. Further, a suction port 21 of the blower 20 is formed in the central portion of the drain pan 19.

As shown in FIGS. 1 and 2, a substantially rectangular decorative panel 22 is attached to the lower surface of the air conditioner body 14 so as to cover the lower opening of the air conditioner body 14.
A suction port 23 communicating with the suction port 21 of the drain pan 19 is formed in the central portion of the decorative panel 22, and a suction grill 24 covering the suction port 23 is detachably attached to the suction port 23 portion. Yes. On the air conditioner body 14 side of the suction grill 24, a filter 25 for removing dust in the air is provided.

Air outlets 26 for sending air after air conditioning into the room are formed at positions outside the suction port 23 of the decorative panel 22 and along each side of the decorative panel 22. Further, each outlet 26 is provided with a flap (not shown) for changing the air direction.
And by operating the air blower 20, indoor air is sucked in from the suction ports 21 and 23, passes through the filter 25, passes through the heat exchanger 18, and is heat-exchanged. Air is configured to be sent indoors.

FIG. 2 is a perspective view of the air blower 20 in the first embodiment of the present invention. FIG. 3 is a side cross-sectional view of the blower 20 in the first embodiment of the present invention. An arrow R in FIG. 2 indicates the direction of rotation of the centrifugal fan 100.
As shown in FIGS. 2 and 3, the blower device 20 includes a centrifugal fan 30, and the centrifugal fan 30 includes a main plate 31 formed in an annular plate shape. The main plate 31 includes an annular plate portion 32 and an inverted frustoconical motor housing portion 33 formed at the center portion of the plate portion 32 and extending downward.
A fan motor 34 is housed in the motor housing portion 33, and a rotating shaft 35 of the fan motor 34 extends downward and is connected to the bottom surface of the motor housing portion 33. Then, the main plate 31 is configured to rotate through the rotation shaft 35 by rotating the fan motor 34.

A shroud 36 is provided below the main plate 31, and the shroud 36 is formed in an annular shape with a circumferential surface formed in an arc shape. The upper edge of the shroud 36 is a discharge side opening 37, and the lower edge of the shroud 36 is a suction side opening 38 having a smaller diameter than the discharge side opening 37.
A plurality of blades 39 are integrally formed between the plate portion 32 of the main plate 31 and the inner peripheral surface of the shroud 36 with a predetermined interval in the circumferential direction. Each of the blades 39 has a twisted shape so that the mounting direction with respect to the main plate 31 and the mounting direction with respect to the shroud 36 are different.

  An orifice 40 is disposed below the shroud 36, and the orifice 40 is formed in an annular shape having a circumferential surface formed in an arc shape. The upper edge of the orifice 40 is a discharge side opening 41 having a smaller diameter than the suction side opening 38 of the shroud 36, and the lower edge of the orifice 40 is a suction side opening 42 having a larger diameter than the discharge side opening 41. Has been. An annular substrate 43 is provided on the outer peripheral side of the suction side opening 42 of the orifice 40.

  In the present embodiment, a plurality of guide fins 44 are provided on the outer peripheral surface of the orifice 40 at predetermined intervals in the circumferential direction. The outermost end at the upper end of each guide fin 44 has a protruding length substantially the same as the outer diameter of the suction side opening 38 of the shroud 36, and the lower end of the guide fin 44 is at the inner end of the substrate 43. It is formed to be located. In the present embodiment, the upper end portion of the guide fin 44 is formed to be inclined so as to be positioned in the direction opposite to the rotation direction of the centrifugal fan 30.

Next, the operation of this embodiment will be described.
By driving the fan motor 34, the centrifugal fan 30 is driven to rotate in a predetermined direction via the rotating shaft 35. By rotating the centrifugal fan 30, indoor air is sucked from the suction ports 21 and 23, and the sucked air is sent from the suction side opening 42 of the orifice 40 to the suction side opening 38 of the shroud 36 (hereinafter referred to as “this”). Air flow is called mainstream).
The air flowing in from the suction side opening 38 of the shroud 36 is substantially parallel formed by the peripheral surface of the shroud 36 and the outer peripheral surface of the motor housing portion 33 of the main plate 31 when viewed in the cross section of the centrifugal fan 30. Are bent by two arc-shaped fluid flow paths, pressurized by a plurality of blades 39, and sent in the centrifugal direction. After the air sent in the centrifugal direction is heat-exchanged by the heat exchanger 18, it is blown into the room through the outlet 26.

On the other hand, a part of the air sent in the centrifugal direction of the centrifugal fan 30 enters the inside of the shroud 36 from the gap between the suction side opening 38 of the shroud 36 and the discharge side opening 41 of the orifice 40 with a swirling component. An air flow that flows in and re-enters the centrifugal fan 30 is generated (hereinafter, this air flow is referred to as a circulation flow).
At this time, in the present embodiment, since the plurality of guide fins 44 are formed on the outer peripheral surface of the orifice 40, the circulation flow is blocked by the guide fins 44 and then re-enters the centrifugal fan 30. Become. Therefore, compared with the case where the guide fins 44 are not formed, the resistance that the circulating flow receives at the time of circulation increases, so that the circulating flow that re-enters the centrifugal fan 30 can be reduced.

  In the present embodiment, the upper end portion of the guide fin 44 is formed so as to be inclined so as to be located in the direction opposite to the rotation direction of the centrifugal fan 30, so that the circulating flow is centrifuged by the guide fin 44. The fan 30 is guided so as to incline in the direction opposite to the rotation direction of the fan 30 and re-enters the centrifugal fan 30. As a result, the inflow angle of the circulating flow becomes an angle close to the inlet angle in the height direction of the blade 39, so that the circulating flow flows in the direction along the surface of the blade 39. As a result, it is possible to reduce the separation flow generated at the front edge of the blade 39.

As described above, in the present embodiment, by forming the guide fins 44 in the orifice 40, the resistance that the circulating flow receives at the time of circulation can be increased and the circulating flow can be reduced. Since it can be made to flow in the direction along the surface of 39, the separation flow generated at the front edge of the blade 39 can be reduced, and the turbulent noise caused by the circulation flow can be remarkably reduced.
Further, by reducing the turbulent noise, the air blowing performance of the centrifugal fan 30 can be improved. As a result, the centrifugal fan 30 can be made small, so that weight reduction and cost reduction can be achieved.

Next, a second embodiment of the present invention will be described.
FIG. 4 is a perspective view of the air blower 20 in the second embodiment of the present invention. FIG. 5 is a side sectional view of the blower 20 in the second embodiment of the present invention. Note that the same parts as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

As shown in FIGS. 4 and 5, also in the present embodiment, a plurality of guide fins 44 arranged at predetermined intervals in the circumferential direction are provided on the outer peripheral surface of the orifice 40 as in the first embodiment. Yes. In the present embodiment, the outermost end of the upper end portion of each guide fin 44 has a protruding length that protrudes radially outward from the outer diameter of the suction side opening 38 of the shroud 36, The outermost end of the lower end portion of the guide fin 44 has a protruding length that protrudes radially outward from the outer diameter of the suction side opening 42 of the orifice 40. That is, in this embodiment, the width dimension of the guide fin 44 is formed larger than that in the first embodiment.
Other parts have the same configuration as in the first embodiment.

  Also in the present embodiment, as in the first embodiment, the fan motor 34 is driven and the centrifugal fan 30 is rotationally driven to suck indoor air from the suction port. It is sent to the inside of the centrifugal fan 30 through the shroud 36, pressurized by a plurality of blades 39, and sent in the centrifugal direction.

On the other hand, the circulating flow of the centrifugal fan 30 is blocked by the plurality of guide fins 44 and then re-enters the centrifugal fan 30. Here, in this embodiment, since the width dimension of the guide fin 44 is formed large, the resistance that the circulating flow receives at the time of circulation can be further increased, and the circulating flow can be further reduced.
In this embodiment, the guide fins 44 are inclined so that the circulation flow is inclined in the direction opposite to the rotation direction of the centrifugal fan 30. An angle close to the entrance angle in the height direction can be set, and the circulating flow can flow in a direction along the surface of the blade 39. As a result, the separation flow generated at the front end edge of the blade 39 can be further reduced.

As described above, also in the present embodiment, as in the first embodiment, by forming the guide fins 44 in the orifice 40, the resistance that the circulating flow receives during circulation is further increased, and the circulating flow is further reduced. In addition, since the circulating flow can flow in the direction along the surface of the blade 39, the separation flow generated at the front edge of the blade 39 can be further reduced, and the turbulent noise caused by the circulating flow is significantly reduced. Can be reduced.
Further, by reducing the turbulent noise, the air blowing performance of the centrifugal fan 30 can be improved. As a result, the centrifugal fan 30 can be made small, so that weight reduction and cost reduction can be achieved.

  In addition, this invention is not limited to the thing of said each embodiment, It can change variously as needed in the range which does not deviate from the meaning of invention.

DESCRIPTION OF SYMBOLS 10 Ceiling embedded indoor unit 14 Air conditioner main body 18 Heat exchanger 20 Blower device 22 Cosmetic panel 30 Centrifugal fan 31 Main plate 34 Fan motor 36 Shroud 37 Discharge side opening 38 Intake side opening 39 Wing 40 Orifice 41 Discharge side opening 42 Inhalation Side opening 44 Guide fin

Claims (3)

A centrifugal fan that is rotationally driven by a fan motor and includes a main plate, a shroud disposed opposite to the main plate, and a plurality of blades disposed between the main plate and the shroud;
An orifice disposed on the air inflow side of the shroud with a predetermined gap between the shroud, and
A plurality of guide fins are provided on the outer peripheral surface of the orifice at a predetermined interval in the circumferential direction, and the shroud side end portion of the guide fin is disposed to be inclined in a direction opposite to the rotation direction of the centrifugal fan. The air blower characterized.   2. The blower according to claim 1, wherein an outermost end of the shroud side end portion of the guide fin is located radially outward from a suction side opening of the shroud.   The blower according to claim 1 or 2, wherein the guide fin has an outermost end portion on the suction side opening side of the orifice positioned radially outward from the suction side opening of the orifice.

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