JP3139447B2 - Cross flow fan - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of a cross flow fan.

[0002]

2. Description of the Related Art A so-called cross-flow fan is provided with a fan rotor composed of a large number of blades in a spiral wind passage formed by a tongue portion and a scroll portion, and in which air flows in a radial direction of the fan rotor. Conventionally, it has been widely used in indoor units for air conditioners and the like.

FIGS. 6 to 8 show examples of the structure of a conventional air conditioner indoor unit having such a cross flow fan.

In FIG. 6 to FIG. 8, reference numeral 2 denotes a cassette type main body housing of the air conditioner indoor unit 1, for example.

Air suction grills 3 and 4 are formed on the upper and front portions of the main body housing 2, respectively, and air outlet openings 5 are formed on the lower front corner portions so as to extend in both the left and right directions. In the main body housing 2, there is formed an air passage from the upstream air suction grilles 3 and 4 to the downstream air blow opening 5.
A cross fin heat exchanger 6 having, for example, a U-shaped cross section is provided inside the upstream air suction grilles 3 and 4, and a rotating shaft 9d as shown in FIG. A plurality of blades (blades) 9b, 9b,... Provided on the outer periphery of the fan rotor 9a via partition plates 9c, 9c,. A cross flow fan 9 including a tongue portion 12 and a scroll portion 10 and the like forming a spiral air passage between the tongue portion 12 and the tongue portion 12 are provided respectively. And
Downstream of the cross flow fan 9, a lower drain pan forming part 12 e of the tongue part 12 and the scroll part 10
And the downstream side extension 10b of the fan rotor 9a
A diffuser-shaped air blowing passage 8 through which the air flow blown from the air is efficiently blown out is formed.

The cross section is formed in the air suction port 13 between the air suction side end 10a of the scroll portion 10 and the air suction side end 12a of the tongue portion 12 forming the spiral wind passage. A fan rotor 9a of the flow fan 9 is provided to extend in the left-right direction and to be rotatable.

As described above, the conventional cross flow fan 9 includes the fan rotor 9a, the tongue 12, the scroll 10
In general, the L-shaped tongue 12 has an opposed surface 12b opposed to the fan rotor 9a at a position where a gap between the tongue 12 and the fan rotor 9a is minimized, as shown in FIG. It has a plane shape that is substantially parallel to a plane that is in contact with the fan rotor 9a.

However, the position where the gap is minimized has a great effect on aerodynamic performance and noise. For example, when the fan rotor 9a rotates, the air exchanged by the heat exchanger 6 is sucked in from the air suction port 13 of the cross flow fan 9 and blown out from the air blowing side. Is blown into the room from the air blow-out opening 5 through the air blow-off opening 5, and at this time, the tongue 12 forming the ceiling-side start end of the air blow-out passage 8 with respect to the air blow-out side end (lower end) 12 c portion The above fan rotor 9
After a part of the air flow blown out of the fan rotor 9a collides with the fan rotor 9a, the air flow is sucked into the fan rotor 9a again. A large concentric vortex is formed eccentric from the rotation center of the rotor 9a toward the tongue 12 side. And
This eddy current is applied to each blade 9b of the fan rotor 9a.
・ ・ Pressure fluctuates when cutting, causing blade pitch sound. This noise is related to the size of the gap between the fan rotor 9a of the cross flow fan 9 and the tongue 12, and if the gap is increased, the noise is reduced, but the suction force is reduced and the blowing efficiency is reduced. Conversely, if the gap is reduced, the air blowing efficiency increases but the noise increases.

Therefore, in general, the clearance between the tongue portion 12 and the fan rotor 9a is determined by taking the above circumstances into consideration, without reducing the air suction force and reducing the noise as much as possible. Designed for relationships.

However, in mass-producing the indoor unit, the tongue 12 and the fan rotor 9 in all products are required.
It is difficult to equalize the gap with the fan rotor 9a depending on the mounting state of the tongue 12 side, and the position with the fan rotor 9a moves slightly up and down. There is also a problem that variations occur in the gaps between the air conditioner and the air outlet, and it is not possible to obtain the ventilation efficiency and noise reduction effect as designed.

Therefore, as one of conventional examples which solves such a problem, there is one disclosed in, for example, JP-A-5-231667. In this conventional example, in order to solve the above-described problem, the center of the tongue 12 facing the fan rotor 9a in the vertical direction, that is, even if the mounting position of the tongue 12 is slightly shifted in the vertical direction, the tongue 12 The gap between the tongue 12 and the fan rotor 9a is minimized by providing a protrusion at a position where the gap between the fan rotor 9a and the fan rotor 9a hardly changes. Is stable without variation due to an assembly error for each product.

[0012]

As described above, when the fan rotor 9a of the cross flow fan 9 rotates, the flow of the air blown to the air blowing side end (lower end) 12c of the tongue 12 is reduced. The parts collide with each other and are sucked into the fan rotor 9a again.
A large concentric vortex eccentric to the tongue 12 side is formed in the blowout region of. Since the center position of the vortex and the size of the vortex greatly affect the aerodynamic performance and the blowing sound of the cross flow fan, it is desirable that the flow of the vortex is stable. However, when the surface 12b facing the fan rotor 9a has a flat tongue shape as in the above-described conventional example, even if a projection is provided, the air flow near the air blowing side end 12c of the tongue 12 may be disturbed. , The change in the pressure loss of the flow path itself cannot be prevented,
The size of the center position of the vortex tends to be unstable. for that reason,
The problem remains that the aerodynamic performance is reduced and the blowing noise is also increased.

The air suction side end 12 of the tongue 12
Since the flow is rapidly changing in the portion a, the downstream vortex is likely to be generated on the downstream side, and the blades 9b and 9 of the fan rotor 9a are formed.
There is a problem that it is difficult for air to smoothly flow into the inlet of b.

Further, the blown air has a very turbulent flow on the lower surface 12d of the tongue 12 facing the air blowing passage 8 downstream from the air blowing end 12c.

[0015] In the conventional crossflow fan, these factors are factors that hinder improvement in aerodynamic performance and noise reduction.

The present invention has been made in order to solve the above-mentioned problems, and the surface of the tongue portion facing the fan rotor is formed in a concave shape so that the tongue portion is formed in the vicinity of the air blowing region tongue portion. It is an object of the present invention to provide a cross-flow fan that improves aerodynamic performance and reduces blowing noise by making the vortex flow to be a stable flow contained in the concave portion.

[0017]

In order to achieve the above object, the present invention comprises the following problem solving means as shown in FIGS. 1 to 5, for example.

That is, the first aspect of the present invention is a cross flow fan comprising a fan rotor 9a between a tongue portion 12 and a scroll portion 10, wherein the tongue portion 12 opposing the fan rotor 9a is provided. Is formed in a substantially arc shape having a center on the scroll portion 10 side from the vicinity of the air suction side end 12a to the air blowout side end 12c so that the gap between the opposite surface 12b and the fan rotor 9a extends from the vicinity of the air suction side end 12a to the air discharge side end 12c. It is characterized in that it has a concave shape that is enlarged and then reduced again.

In the configuration of the cross flow fan of the present invention, as described above, the tongue 12 facing the fan rotor 9a is used.
Is formed in the air blowing region of the fan rotor 12a in the vicinity of the tongue portion 12, so that the vortex flows in the surface 12b facing the concave fan rotor 9a. The center position becomes a stable vortex.

The concave portion of the opposing surface 12b of the tongue portion 12 facing the fan rotor 9a has an air suction side end portion 1b.
The air outlet side end 12c of the tongue 12 is enlarged and reduced once again in an arc shape centered on the scroll portion 10 from the side 2a to the air outlet side end 12c. It is directed toward the rotor 9a. Therefore, the flow that has hitherto collided with the air outlet side end portion 12c of the tongue portion 12 and has been disturbed is smoothly divided into two by the fan rotor 9a side and the air outlet passage 8 side, and flows smoothly. The vortex in the part is eliminated.

As a result, there is no change in the pressure loss in the flow passage, and the center position of the vortex in the air blowing region on the tongue side of the fan rotor 9a is more stable, so that the aerodynamic performance is improved and the blowing noise is reduced. You.

In the cross flow fan according to the second aspect of the present invention, the shape of the opposing surface 12b of the tongue portion 12 facing the fan rotor 9a extends from near the air suction side end 12a to the air blow side end 12c. It has a concave shape connecting two arcs having a center on the scroll portion 10 side, whereby the opposing surface 12b of the tongue portion 12 facing the fan rotor 9a is connected to the opposing surface 12b and the fan rotor 9a. 2. The concave shape according to claim 1, wherein the gap between the air inlet side end 12a and the air outlet side end 12c is enlarged in a substantially arc shape centered on the scroll portion 10 side and then reduced again. Is formed.

In the cross flow fan according to the third aspect of the present invention, the air suction side of the two arcs forming the concave shape of the opposing surface 12b of the tongue portion 12 facing the fan rotor 9a according to the second aspect of the present invention. The concave shape according to the first aspect of the present invention is formed by making the radius of curvature of the arc on the end 12a side larger than the radius of curvature of the arc on the air blowing side end 12c side.

In the cross flow fan according to the fourth aspect of the present invention, the gap between the fan rotor 9a on the opposing surface 12b of the tongue 12 and the fan rotor 9a according to the first, second or third aspect of the present invention. The minimum position is the vicinity of the air blowing side end 12c of the surface 12b facing the fan rotor 9a.

Therefore, it is possible to prevent the blow-out air from flowing into the fan rotor 9a more than necessary, so that the vortex is more stable and the air suction force is improved.

Further, in the cross flow fan according to the fifth aspect of the present invention, the shape of the lower surface 12d of the tongue facing the air blowing passage 8 according to the first, second, third or fourth aspect of the present invention is formed on the air blowing passage 8 side. The air flow toward the air blowing passage 8 in the flow divided into two at the air blowing side end 12c of the tongue 12 as described above is The air flows smoothly along the lower surface 12d of the tongue forming the ceiling of the outlet passage 8.

In the cross flow fan according to the sixth aspect of the present invention, the air suction side end 12a of the tongue 12 in the first, second, third, fourth or fifth aspect of the present invention has an arcuate surface.

Therefore, the flow on the air suction side does not suddenly change from the vicinity of the air suction side end 12a to the point of closest approach to the fan rotor 9a, and the flow between the blades 9b, 9b,. It will flow in smoothly.

[0029]

As described above, according to the crossflow fan of the present invention, a high-performance crossflow fan having high aerodynamic performance and low blow sound can be provided.

[0030]

(Embodiment 1) FIGS. 1 and 2 show the structure and operation of a cross flow fan according to Embodiment 1 of the present invention.

First, in FIG. 1 and FIG.
Reference numeral 9 denotes a cross flow fan substantially the same as that shown in FIGS. 6 to 8 except for the structure of the tongue portion, 9a denotes a fan rotor of the cross flow fan 9, 10 denotes a scroll portion, and 12 denotes a tongue portion.

On the downstream side of the cross flow fan 9, a diffuser-shaped air blowing passage 8 described later is formed by the drain pan forming portion 12e of the tongue portion 12 and the downstream extension portion 10b of the scroll portion 10. Yes,
The fan rotor 9a is provided at an air suction port 13 formed between an air suction side end 10a of the scroll portion 10 and an air suction side end 12a of the tongue portion 12, and a downstream air outlet portion thereof. As shown in FIG. 6 described above, the opening is continuous with the air blowing opening on the main body housing side.

The scroll shape of the scroll portion 10 is, for example, a continuous surface of a plurality of arc portions having different curvature centers and curvature radii, and the shape of the air outlet portion is located at the most downstream side of the scroll portion 10. The diffuser shape is such that a tangent extends in the air blowing direction from the arc surface of the arc portion to be formed.

On the other hand, the tongue 12 has a scroll portion in which a gap between an opposing surface 12b facing the fan rotor 9a and the fan rotor 9a extends from near the air suction side end 12a to the air blow side end 12c. It is formed in an arcuate concave shape that increases once in a substantially arcuate shape with the center on the 10 side and then decreases again.

The tongue 12 facing the fan rotor 9a
More specifically, the concave shape of the facing surface 12b of the air outlet side end 12c is near the air suction side end 12a.
, The two arc-shaped surfaces each having a center on the scroll portion 10 side are connected to each other, and the curvature of the arc-shaped surface on the air suction side end 12a side of the two arc-shaped surfaces forming the concave shape is formed. Set the radius to the air outlet side end 12c
By making the radius of curvature larger than the radius of curvature of the side arc surface, the gap size is changed as described above.

The fan rotor 9a
Rotor 9a on the opposing surface 12b of the tongue 12 opposing the
The position where the gap between them is minimized is set to the air blowing side end 12c of the facing surface 12b.

As described above, in the configuration of the cross flow fan of the present embodiment, the fan rotor 9a of the tongue 12
The shape of the opposed surface 12b is a concave shape composed of an arc surface centered on the scroll portion 10 side, so that, for example, as shown in FIGS. Since the vortex formed in the region is accommodated in the concave portion, the center position is a stable vortex.

In this case, the concave surface of the facing surface 12b has a concave shape formed by connecting two arcs centered on the scroll portion 10 from the vicinity of the air suction side end 12a to the air discharge side end 12c. It is,
Moreover, of the two arcs forming the concave surface shape, the radius of curvature of the arc on the air suction side end 12a side is made larger than the radius of curvature of the arc on the air discharge side end 12c side to face the fan rotor 9a. Conventionally, by making the radius of curvature of the arc on the blowout side of the facing surface 12b of the tongue portion 12 relatively small and directing the air blowout side end 12c of the tongue portion 12 to the fan rotor 9a side, the air of the tongue portion 12 has conventionally been The flow that has collided with the blow-out end portion 12c and has been disturbed is smoothly split into two by the fan rotor 9a side and the air blow-out passage 8 side, and flows smoothly.

As a result, the center position of the vortex is more stable, the flow path loss is reduced, the aerodynamic performance is improved, and the blowing noise is reduced.

(Embodiment 2) Next, FIG. 3 shows a configuration of a cross flow fan according to Embodiment 2 of the present invention.

In the configuration of the cross flow fan according to the present embodiment, as in the first embodiment, in the cross flow fan 9 having the fan rotor 9a between the tongue portion 12 and the scroll portion 10, In substantially the same manner, the shape of the facing surface 12b of the tongue portion 12 facing the fan rotor 9a is as follows.
From the vicinity of the air suction side end 12a to the air discharge side end 12c, the two arcs having the center on the scroll part 10 side are connected to form a concave shape. Of the two arcs forming the concave shape, air is formed. The radius of curvature of the arc on the suction side end 12a side is set to the air blowing side end 12c.
By making the radius of curvature larger than the radius of curvature of the side arc, the opposing surface 12 of the tongue 12 facing the fan rotor 9a
b, the gap between the facing surface 12b and the fan rotor 9a is enlarged in a substantially arc shape having a center on the scroll portion 10 side from the vicinity of the air suction side end 12a to the air discharge side end 12c. After that, it is formed in a concave shape that shrinks again.

Therefore, first, in the configuration of the cross flow fan of the present embodiment, as described above, the fan rotor 9a
The shape of the opposing surface 12b of the tongue portion 12 facing the tongue portion 12 is concave, so that the vortex formed in the air blowing region of the fan rotor 12a near the tongue portion 12 faces the fan rotor 9a having the concave shape. A stable vortex flows at the center position that flows within the surface 12b.

The concave portion of the opposing surface 12b of the tongue portion 12 facing the fan rotor 9a is formed at the air suction side end portion 1.
The air outlet side end 12c of the tongue 12 is enlarged and reduced once again in an arc shape centered on the scroll portion 10 from the side 2a to the air outlet side end 12c. It is directed toward the rotor 9a. Therefore, the flow that has hitherto collided with the air outlet side end portion 12c of the tongue portion 12 and has been disturbed is smoothly divided into two by the fan rotor 9a side and the air outlet passage 8 side, and flows smoothly. The vortex in the part is eliminated.

As a result, there is no change in the pressure loss in the flow path, and the center position of the vortex in the air blowing region on the tongue side of the fan rotor 9a is more stable, so that the aerodynamic performance is improved and the blowing noise is reduced. You.

In addition to this, the position where the distance between the opposing surface 12b of the fan rotor 9a of the tongue 12 and the fan rotor 9a is minimized is determined by the air on the opposing surface 12b of the tongue 12 opposing the fan rotor 9a. Spout side end 12c
By providing it near, while making the eddy current more stable,
Further, the shape of the lower surface 12d of the tongue portion 12 facing the air blowing passage 8 side is a circular arc shape having a center on the air blowing passage 8 side.

Accordingly, of the flow divided into two at the air outlet side end 12c of the tongue 12, the air flow on the outlet side flows more smoothly along the lower surface 12d of the tongue 12.

With such a configuration, in addition to the operation of the configuration of the first embodiment as described above, the aerodynamic performance is further effectively improved and the blowing noise is reduced.

(Reference Example) Next, FIG. 4 shows a configuration of a cross flow fan according to a reference example related to the present invention.

In the structure of the cross flow fan according to the present embodiment, the flow near the tongue 12 on the side of the air inlet 13 in the structure of the conventional cross flow fan shown in FIG. By forming the shape of the suction side end 12a into a substantially 1/4 arc (arc having a circumferential angle of 90 °) from the point of closest approach to the fan rotor 9a to the suction side end, the air suction side end is formed. 12a suppresses a rapid change in the flow downstream of the fan rotor 9a.
a can smoothly flow between the blades 9b.

With this configuration, the aerodynamic performance is more effectively improved and the blowing noise is reduced as compared with the conventional configuration shown in FIG. 8 because at least the flow on the air suction side becomes smoother. You.

Third Embodiment FIG. 5 shows a configuration of a cross flow fan according to a third embodiment of the present invention.

The configuration of the crossflow fan according to the present embodiment is obtained by further combining the configuration of the reference example with the configuration of the crossflow fan according to the second embodiment.

With such a configuration, the operation of the configuration of the above-described reference example is further synergized with the operation of the configuration of the first and second embodiments, whereby the aerodynamic performance is more effectively improved and the blowing noise is reduced. Is done.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a configuration of a cross flow fan according to Embodiment 1 of the present invention.

FIG. 2 is an enlarged view showing an operation of a main part of the cross flow fan.

FIG. 3 is a cross-sectional view illustrating a configuration of a cross flow fan according to Embodiment 2 of the present invention.

FIG. 4 is a sectional view showing a configuration of a cross flow fan according to a reference example related to the present invention.

FIG. 5 is a sectional view showing a configuration of a cross flow fan according to Embodiment 3 of the present invention.

FIG. 6 is a cross-sectional view illustrating a configuration of an air conditioner indoor unit including a conventional cross flow fan.

FIG. 7 is a perspective view of a fan rotor unit of the indoor unit.

FIG. 8 is an enlarged sectional view of a main part showing a problem of the cross flow fan of the indoor unit.

[Explanation of symbols]

8 is an air passage, 9 is a cross flow fan, 9a is a fan rotor, 10 is a scroll portion, 12 is a tongue, 12a is an end of the tongue on the air suction side, 12b is a surface of the tongue facing the fan rotor, 12c is the end of the tongue on the side of air blowing, 1
3 is an air suction port.

Claims (6)

(57) [Claims] 1. A cross-flow fan comprising a fan rotor (9a) between a tongue (12) and a scroll (10), wherein the tongue (12) faces the fan rotor (9a). ), The gap between the facing surface (12b) and the fan rotor (9a) extends from near the air suction side end (12a) to the air blowing side end (12c). Scroll part (1
0) A cross-flow fan characterized by having a concave shape that expands into an arc-shaped surface centered on the side and then contracts again. 2. The concave shape of the opposing surface (12b) of the tongue (12) opposing the fan rotor (9a) extends from the vicinity of the air suction side end (12a) to the air blowing side end (12).
2. The cross flow fan according to claim 1, wherein the cross flow fan has a concave shape formed by connecting two arc surfaces each having a center on the scroll portion (10) side. 3. The two arc surfaces forming the concave surface of the opposing surface (12b) of the tongue portion (12) opposing the fan rotor (9a) have the curvature radius of the air suction side arc surface set to the air blow side arc. 3. The cross flow fan according to claim 2, wherein the radius of curvature is larger than the radius of curvature of the surface. 4. The position where the gap between the opposing surface (12b) of the tongue (12) opposing the fan rotor (9a) and the fan rotor (9a) is minimized is set to the opposing surface (12b).
The cross flow fan according to claim 1, 2 or 3, wherein the air blow side is located near an end of the air blowing side. 5. The shape of the tongue surface (12d) facing the air blowing passage (8) is a concave shape formed of a circular arc centered on the side of the air blowing passage (8). The crossflow fan according to 1, 2, 3, or 4. 6. The air suction side end (1) of the tongue (12).
2. The method according to claim 1, wherein 2a) is an arc surface.
The crossflow fan according to 3, 4 or 5.