JP2001280288A - Impeller structure of multiblade blower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the air supply efficiency of a multiblade blower, such as a crossflow fan, etc., and to reduce the generation of air supply noise. SOLUTION: A multiblade blower 9 is provided with an impeller 9a consisting of a number of blades 19, 19, etc., juxtaposed at given pitches in a peripheral direction. A camber line radius R2 on the outer periphery C2 of the impeller consisting of the blades 19, 19, etc., is increased to a value higher than a camber line radius R1 on the inner periphery C1 side of the impeller.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of an impeller of a multi-blade blower such as a cross flow fan.

[0002]

2. Description of the Related Art For example, a cross-flow fan (through-flow type blower) generally has an impeller composed of a number of blades in a spiral fan housing, and a multi-blade blower structure in which air flows in a radial direction of the impeller. It has become.

FIGS. 6 to 8 show an example of a configuration in which such a cross-flow fan is applied to an indoor unit for an air conditioner.

First, FIG. 6 shows the overall structure of the indoor unit 1 in the air conditioner constructed by employing the cross flow fan 9.

In FIG. 6, reference numeral 2 denotes a main body casing of the indoor unit 1 for an air conditioner. Air suction grills 3 and 4 are formed on an upper surface side and an upper part on a front side, respectively. Is provided with an air blowing opening 5.

In the main body casing 2, there is provided an air passage 7 from the air suction grills 3, 4 to the air outlet 5, and upstream of the air passage 7, the air suction grill is provided. A heat exchanger 6 having a V-shaped cross section facing 3 and 4 has a cross flow fan 9 and a tongue 12 downstream thereof.
And a scroll unit 10 are sequentially provided. The tongue portion 12 and the scroll portion 10 form a spiral fan housing.
The impellers (fan rotors) 9a of the cross flow fan 9 are installed inside 0a and 12a so as to be rotatable in the arrow direction.

As shown in FIG. 7, the tongue portion 12 is located on the side of the air suction grille 4 and has a predetermined height along the outer diameter of an impeller (fan rotor) 9a of the cross flow fan 9. Is provided.

The lower side is connected to an air flow guide portion 12b which also serves as a drain pan below the heat exchanger 6. The air flow guide portion 12b allows the air flow blown from the impeller (fan rotor) 9a of the cross flow fan 9 to efficiently flow the air blow opening 5a.
The air outlet passage 8 having a diffuser structure as shown in the drawing is formed on the downstream side together with the downstream portion 10b of the scroll portion 10 toward the air outlet opening 5 so as to be blown out from the direction.

Reference numeral 14 denotes the scroll unit 10
A wind direction changing plate provided in the air blowing passage 8 having a diffuser structure between the air flow guide portion 12b below the tongue portion 12 and the air flow guide portion 12b.

The shape of the tongue 12 is formed as shown in the figure. The tongue 12 passes through the heat exchanger 6 from the impeller (fan rotor) 9a of the cross flow fan 9 to the air blowing opening 5. The air flow is blown out in a direction orthogonal to the rotation axis 15 of the impeller (fan rotor) 9a while being curved in the rotation direction as a whole as shown by a chain line arrow, and then flows into the air blowing passage 8. Along the air blowing opening 5 and is blown out to the front side.

FIG. 8 shows the cross flow fan 9.
The structure of the impeller (fan rotor) 9a of FIG.

The impeller (fan rotor) 9a is shown in the figure in the circumferential direction of the outer peripheral edge of a plurality of circular support plates 16, 16... Like many long blades (blades) 1
9 and 19 are inserted and supported at a predetermined pitch in a state parallel to the rotary shaft 15, and both ends thereof are fixed by circular hub plates 17, 17.

When the impeller 9a is rotated by the fan motor as shown in FIG. 6, first, air is sucked in from the air suction port formed on one side surface of the scroll portion 10 as shown by an arrow, so that the impeller is rotated. The air is blown out in the centrifugal direction on the air outlet side of the vehicle 9a as indicated by the arrow, and then blown out from the air blowing opening 5 at the end of the scroll passage of the scroll portion 10.

By the way, the blades 19 of the impeller 9a of the cross flow fan 9 as described above, for example, as shown in FIG. Radius R, the inlet angle θ _{1 of} the air flow, the outlet angle θ ₂ of the air flow, and the mounting angles of the impeller 9a with respect to the inner and outer peripheral sides C ₁ and C ₂ (the blades with respect to the diameter a of the impeller 9a). The blowing efficiency and noise characteristics are determined by the constituent requirements such as the inclination angle of the string b) θ ₃ and the plate thickness D.

[0015] In this regard, in the conventional cross-flow fan configured, for example, as shown in FIG. 9, the inner circumference C ₁ side from the impeller 9a of the thickness D and the camber line radius R impeller 9a of the blade 19 single arcuate surface shape is formed, the desired inlet angle theta _1, desired exit angle theta _2, set the desired setting angle theta _3, as much as possible blowing efficiency of each fixed to the outer C ₂ side To obtain an impeller structure with high noise and low noise.

These points are the same as in the case of a so-called sirocco fan, for example, which has many common features as a multi-blade fan.

[0017]

However, in the above-mentioned conventional blade formed in a single circular arc shape, the region of the cross-flow fan 9 where the air flow is blown out of the impeller 9a is arranged in the blade 1 side.
It has been confirmed by computer simulation and experiments that the flow largely separates in the wake area A of the blade 19 when the blade 9 passes. Further, as a result of sound source search, it was confirmed that the separation of the airflow in the downstream area A of the blade is a main factor of the noise of the cross flow fan.

In the cross flow fan as described above, as is apparent from FIGS. 6 and 7, the impeller 9a
When the blades 19 pass through the upstream suction side area and when they pass through the downstream blow side area, the
The flow direction with respect to the nozzle 9 is opposite to the above. In the case of a single arc-shaped surface as described above, if the flow is designed to suppress the separation of the flow in the downstream area A of the blade when passing through the blow-out area, the suction-side area will be reversed. In this case, there is a problem that the flow around the blades 19 is deteriorated, the blowing efficiency is reduced, and the blowing noise is increased.

The present invention has been made in order to solve such a problem. The radius of the warp line of the entire blade is made larger on the outer peripheral side of the impeller than on the inner peripheral side of the impeller, so that the wake area in the downstream area of the blade is improved. It is an object of the present invention to provide an impeller structure of a multi-blade blower in which the amount of separation is reduced, the blowing efficiency is increased, and the noise over a wide band can be reduced as effectively as possible.

[0020]

Means for Solving the Problems Claims 1 to 3 of this application
In order to achieve the above object, the present invention is provided with the following means for solving the problems.

(1) The invention according to the first aspect of the present invention is, for example, as shown in FIGS. 1 to 3, in a fan-shaped housing 10 or 12 having a predetermined shape, a plurality of fan housings are juxtaposed at a predetermined pitch in a circumferential direction. a multiblade fan 9 made comprises a vane 19 consists of ... impeller 9a, each blade 19, 19, ... of the impeller outer circumference C ₂ side of the warp beam radius R ₂ of the impeller It is characterized in that greater than camber line radius R ₁ of the circumferential C ₁ side.

According to such a configuration, the inner circumference C _{1 of} the impeller is provided.
Large second arcuate surface the radius of curvature extending to the outer periphery C ₂ side from the first arcuate surface small first arcuate surface of small radius of curvature from the side to the impeller outer circumference C ₂ side direction and the inner circumferential C ₁ side curvature And a blade shape composed of two sets of arc surfaces that are smoothly continuous with each other.

The blades 19, 19,... Of this shape have a blade shape downstream of the blow-off side, which is nearly straight, and the wake flowing between the blades 19, 19,.
9, 19... (A negative pressure surface), and the amount of peeling is effectively reduced.

As a result, broadband noise is reduced as much as possible.

(2) The invention according to claim 2 The present invention is, for example, as shown in FIGS. 1 to 3, in the configuration of the invention according to claim 1, wherein the inner circumference C ₁ of each of the blades 19, 19. thickness D from the side toward the impeller outer circumference C ₂ side
Are substantially the same.

The effect of the invention of the first aspect, the thickness D of toward the impeller outer circumference C ₂ side from the impeller inner circumference C ₁ side of each blade 19, ... of the impeller 9, substantially the same It is also realized effectively in the case.

(3) Invention of Claim 3 According to the present invention, as shown in FIGS. 1 to 3, for example, in the configuration of the invention of Claim 1, the inner circumference C ₁ of each of the blades 19, 19. thickness D from the side toward the impeller outer circumference C ₂ side
But greatly impeller inner circumference C ₁ side, is characterized in that gradually decreases to the impeller outer circumference C ₂ side direction.

The effect of the invention of the first aspect, the thickness D of toward the impeller outer circumference C ₂ side from the impeller inner circumference C ₁ side of each blade 19, ... of the impeller 9a is, within the impeller larger in the circumferential C ₁ side, in the case of those Eafuoiru shape gradually decreases toward the said impeller outer circumference C ₂ side, it is possible to effectively achieve the Eafuoiru effect at the air outlet side region upstream of the impeller 9a , The separation of the flow from the upstream region to the entire downstream region of the blades 19 can be effectively reduced in the region, and the blowing efficiency can be more effectively improved and the blowing noise can be reduced. can do.

[0029]

As described above, according to the structure of the impeller of the multi-blade blower according to the present invention, it is possible to provide a high-performance multi-blade blower having as high a blowing efficiency as possible and low aerodynamic noise.

[0030]

1 to 4 show the configuration and operation of an impeller structure of a multi-blade blower according to an embodiment of the present invention.

First, FIG. 1 shows a cross-flow as an example of a multi-blade blower applied between the tongue portion 12 and the scroll portion 10 of the air conditioner indoor unit 1 (see FIG. 6) similar to the above-mentioned conventional example. The structure of an impeller (fan rotor) 9a portion of the fan 9 is shown in an enlarged manner.

The impeller (fan rotor) 9a has a plurality of circular support plates 16, 16,... as shown, juxtaposed in parallel to fitted support and the rotary shaft 15 a large number of elongate vane (blade) 19, 19 ... at a predetermined pitch in the predetermined mounting angle theta _3, which Each end of each blade 19, 19.
Is fixed.

When the impeller 9a is rotated by a fan motor (not shown) as shown in FIG. 1, air is first sucked from an upstream air inlet formed on one side of the scroll portion 10 as shown by an arrow. Then, air is blown out in the centrifugal direction downstream of the impeller 9a, and then blown out from the air blowing opening at the end of the scroll passage 8 of the scroll portion 10.

In the case of this embodiment, each of the blades 19 of the impeller 9a has a substantially constant plate thickness D, as shown in FIG. the camber line radius R ₂ of the outer circumference C ₂ side (R ₁ = 11 mm for example, as an example, R ₂ = 20 mm) is increased to be configured than the inner circumference C ₁ side of the camber line radius R ₁ of the impeller 9a, inlet angle theta _1, as the exit angle theta ₂ is an optimum value, is mounted at the desired mounting angle theta _3.

[0035] Thus, according to such a configuration, the impeller first arcuate surface 9a smaller from the inner circumference C ₁ side radius of curvature on the outer peripheral C ₂ side direction of the inner peripheral side of curvature first small radius of
Can be obtained vanes shaped like the arc surface of the cross consists of two pairs of arcuate surface smoothly continuous to the illustrated and large second arcuate surface of a radius of curvature which extends to the outer periphery C ₂ side direction.

In the blades 19, 19,... Of this shape, the blade shape in the wake area A on the blow-out side of the impeller 9a becomes almost straight. For example, as shown in FIG.
The wake that flows between 9, 19,... Flows smoothly along the blade surface (negative pressure surface), and the amount of separation is effectively reduced as compared with the conventional case (see a comparison with the conventional example in FIG. 10). .

As a result, as shown in the graph of FIG. 4, for example, the broadband noise is reduced as much as possible in the entire region from the small air volume region to the large air volume region as compared with the conventional example.

As a result, according to the structure of the impeller of the multi-blade blower according to the embodiment of the present invention, it is possible to provide a multi-blade blower having as low aerodynamic noise as possible and high fan efficiency.

[0039] (Modification 1) In the configuration of the embodiment of the present invention, as described above, the outer peripheral C ₂ a thickness D of the blade 19, 19, ..., from the inner circumference C ₁ side of the impeller 9a The structure was almost the same on the side.

However, each impeller 1 of the impeller 9a of the present invention is used.
9, 19 ... are, for example, as shown in FIG. 5, in the configuration of the above embodiment, further, the thickness D, greatly impeller inner circumference C ₁ side of each blade 19, 19 ... to one, it may be configured to Eafuoiru shape as gradually decreases toward the outer periphery C ₂ side from the portion.

As described above, each blade 19, 1 of the impeller 9 is used.
9 the thickness D of the impeller inner circumference C ₁ side ... to the outer C ₂ side, large at the inner circumference C ₁ side, when the Eafuoiru shape becomes gradually smaller toward the outer periphery C ₂ side, the blade Since the air oil effect can be effectively realized in the upper part of the air outlet side of the vehicle 9a, the flow from the upstream region to the downstream region of the blades 19, 19,... Thus, the blowing efficiency can be further improved, and the noise in a wide band can be more effectively reduced.

(Modification 2) The structure similar to that of the above embodiment is not limited to the case of the cross flow fan 9 as described above, and similarly applies to a multi-blade blower such as a so-called sirocco fan. It can be applied and a similar effect can be realized.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a structure of an impeller of a multi-blade blower (cross flow fan) according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view showing a configuration of a blade of the impeller unit.

FIG. 3 is an explanatory view showing an operation of a blade of the impeller unit.

FIG. 4 is an explanatory diagram showing the effect of reducing the separation vortex in the wake region by the blade structure of the impeller unit in comparison with the case of the conventional blade structure.

FIG. 5 is a diagram showing a structure of a blade of an impeller according to a first modification.

FIG. 6 is a cross-sectional view showing a configuration of an air conditioner indoor unit configured by employing a multi-blade blower (cross flow fan).

FIG. 7 is a multi-blade blower (cross flow fan) of the indoor unit.
It is sectional drawing of a part.

FIG. 8 is an enlarged perspective view of a main part showing a configuration of an impeller portion of the multi-blade blower (cross flow fan).

FIG. 9 is a diagram showing general components of the blades of the impeller unit.

FIG. 10 is a view showing a conventional structure of a blade of the impeller unit.

FIG. 11 is an explanatory diagram showing a separation vortex generation phenomenon in a wake region caused by a conventional structure of the blade of the impeller.

[Explanation of symbols]

9 is a cross flow fan, 9a is an impeller of a cross flow fan, 10 is a scroll part, 12 is a tongue, 19 is a blade, 19a is an inner circumference, 19b is an outer circumference, θ ₁ is an entrance angle, θ ₂ is an exit angle, theta ₃ is mounted angle, R ₁ is the inner circumferential side camber line radius, R ₂ is an outer peripheral side camber line radius.

 ────────────────────────────────────────────────── ─── Continued on the front page F term (reference) 3H031 AA03 AA07 AA13 BA02 BA03 BA05 BA06 BA12 BA15 BA22 BA35 3H033 AA02 AA18 BB02 BB09 CC01 DD06 DD12 DD17 DD19 EE05 EE06 EE08 EE19

Claims (3)

[Claims] 1. A fan housing having a predetermined shape.
2) An impeller (9a) composed of a number of blades (19), (19),... Arranged side by side at a predetermined pitch in the circumferential direction.
, The radius of curvature (R ₂ ) of each of the blades (19), (19)... On the outer periphery (C ₂ ) side of the impeller is defined as the inner periphery of the impeller (C). impeller structure of the multi-blade fan, characterized in that is larger than ₁₎ of the camber line radius (R _1). 2. The plate thickness (D) of each of the blades (19), (19)... From the inner circumference (C ₁ ) side to the outer circumference (C ₂ ) side of the impeller is substantially the same. The impeller structure of a multi-blade blower according to claim 1, wherein: 3. The plate thickness (D) of each of the blades (19), (19)... From the inner circumference (C ₁ ) side to the outer circumference (C ₂ ) side of the impeller is equal to the inner circumference (C _{1). 2.} The impeller structure of a multi-blade blower according to claim 1, wherein the structure is large on the side of ( ₁ ) and gradually decreases in the direction of the outer circumference (C2) of the impeller.