JP2715784B2 - Cross flow fan device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cross flow fan device used for an indoor unit of an air conditioner.

[0002]

2. Description of the Related Art In an air conditioner, an indoor unit equipped with a cross-flow fan has recently been remarkably reduced in thickness. The direction desired for the cross flow fan is often different due to the distance and the positional relationship between the vessel and the cross flow fan. This reduces the amount of air discharged from the cross flow fan, which is one of the causes of the performance degradation of the cross flow fan.

A method for increasing the amount of air discharged from a cross flow fan is disclosed in Japanese Patent Application Laid-Open No. 63-189699. In this embodiment, as shown in FIG. 4, a projection 54 is provided on a back plate 53a of a housing 53 accommodating a cross flow fan 51 and a heat exchanger 52 disposed on the suction side thereof. The suction air volume of the flow fan 51 is increased. FIG.
, 55 is a scroll, and 56 is a suction grill.

[0004]

However, in the conventional example in which the projection 54 is provided on the back plate 53a to increase the suction air flow as shown in FIG. 4, a sufficient increase in the discharge air flow could not be expected.

The present invention has been made in view of the above circumstances, and pre-swirls the air flow sucked into the cross flow fan in the direction opposite to the rotation direction on the suction side of the cross flow fan. The purpose is to increase the discharge air volume and improve its performance.

[0006]

A cross-flow fan device according to the present invention includes a cross-flow fan 1 on the suction side.
A plurality of guide vanes 7 are arranged in an arc shape concentric with the rotation center P of the cross flow fan 1, and these guide vanes 7
The guide angle between the tangent line A of the air inlet side end 71 passing through the rotation center P and the intersection line B orthogonal to the tangent line A and the tangent line C of the air outlet side end 72 is 20 to 50 degrees. It is set.

[0007]

According to the cross-flow fan device thus configured, the plurality of guide vanes 7... Perform the same function as the centripetal fan on the suction side of the cross-flow fan 1.

[0008]

FIG. 1 is an explanatory view of an indoor unit of an air conditioner using a cross flow fan device according to an embodiment of the present invention, and FIG. 2 is an enlarged view of the main part. In FIG. 1, 1 is a cross flow fan, 2 is a heat exchanger arranged on the suction side of the cross flow fan 1, 3 is a housing, 5 is a scroll, and 6 is a suction grill.

In this indoor unit, a plurality of guide vanes are formed in an arc shape concentric with the rotation center P of the cross flow fan 1 on the suction side of the cross flow fan 1 between the cross flow fan 1 and the heat exchanger 2. 7 are arranged at the same pitch as the blade pitch of the cross flow fan 1. R indicates the rotation direction of the cross flow fan. As shown in FIG. 2 in a further enlarged manner, each guide vane 7 has a tangent A of the air inflow side end 71 passing through the rotation center P and an intersection line B orthogonal to the tangent A and an air outflow. The guide angle α between the side end 72 and the tangent C is 20 to 50.
Set to degree.

In the cross-flow fan device thus configured, the air flow passing through the heat exchanger 2 from the suction tool 6 due to the rotation of the cross-flow fan 1 hits the guide vanes 7 so that the flow direction is changed. 1 is changed into the direction opposite to the rotation direction R and is sucked into the cross flow fan 1. In this case, the guide vanes 7 function similarly to the centripetal fan on the suction side of the cross flow fan 1. As a result, the amount of air blown into the cross flow fan 1 increases, thereby increasing the amount of air discharged, thereby improving the performance of the cross flow fan 1.

FIG. 3 shows a change in the discharge air amount when the guide angle α is variously changed in the cross flow fan device of the embodiment. In the same figure, A is a characteristic of a device having only a cross flow fan without a guide blade, and B, C, and D are each a guide angle α of the guide blade of 3;
0 °, 45 °, and 90 ° are characteristics of the cross flow fan device, and E and F indicate that the guide angle α of the guide blade is −4, respectively.
It is a characteristic of the cross flow fan device of 5 degrees and -30 degrees. The vertical axis represents the number of rotations of the cross flow fan.

As is apparent from FIG. 3, when the guide angle α of the guide blade is positive, that is, as shown schematically in the lower right of FIG. 3, the bending direction and guide of the blade (lower stage) of the cross flow fan. In the case where the bending direction of the blade (upper stage) is opposite (B, C), and in the case where the guide blade is flat (D), the discharge air volume increases as compared with the device (A) using the cross flow fan alone. And the guide angle α of the guide blade
Is negative, that is, when the bending direction of the blade (lower stage) of the cross flow fan and the bending direction of the guide blade (upper stage) are the same (E, F), the discharge air volume is It is smaller than the device (A).

It is clear from the above that if the guide angle α is 0 to 90 degrees, the discharge air volume increases and the performance is improved. However, when the guide angle α is set to a positive angle close to 90 degrees, the effect of improving the performance does not appear so remarkably. If the guide angle α is an angle close to 0 °, the flow direction of the air flow is extremely changed by the guide blades, and a phenomenon that the noise is increased undesirably occurs. Therefore, in the present invention, the guide angle α is set to 20
By limiting the range to 50 degrees, the effect of improving the performance is remarkably exhibited, and the noise can be suppressed to a small level. When the guide angle α is 20 to 50 degrees, the airflow immediately before being sucked into the crossflow fan is given a pre-swirl without difficulty, and it was confirmed that the guide blades functioned similarly to the centripetal fan.

In the above embodiment, the pitch of the plurality of guide blades 7 is set to the same pitch as the blade pitch of the cross flow fan 1, but the pitch of the guide blades 7 is different from the pitch of the cross flow fan 1. You may. Further, in the embodiment, although the guide vanes 7 are provided over the entire circumference on the suction side of the cross flow fan 1, it has been confirmed that the performance is improved even when provided only in a part thereof.

[0015]

According to the present invention, a plurality of guide vanes are arranged in a row in an arc shape concentric with the rotation center of the cross flow fan on the suction side of the cross flow fan. There is an effect that the suction air flow rate of the flow fan increases, which increases the discharge air flow rate and improves the performance. In addition, the guide vane has a tangent at the air inflow side end passing through the center of rotation of the cross flow fan,
In addition, since the guide angle between the intersection line perpendicular to the tangent line and the tangent line at the air outflow end is set to 20 to 50 degrees, the performance improvement by the centripetal action becomes remarkable.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram when a cross flow fan device according to an embodiment of the present invention is applied to an indoor unit of an air conditioner.

FIG. 2 is an enlarged view of a main part of FIG. 1;

FIG. 3 is a drawing-substitute graph showing the performance of a cross-flow fan device in terms of a discharge air volume.

FIG. 4 is an explanatory diagram in a case where a cross-flow fan device according to a conventional example is applied to an indoor unit of an air conditioner.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 cross flow fan 7 guide blade 71 air inlet side end of guide blade 72 air outlet side end of guide blade P rotation center of cross flow fan A tangent to air inlet side end of guide blade B cross line C guide blade Tangent line at the air outlet side α Guide angle

Claims (1)

(57) [Claims] 1. A suction side of a cross flow fan (1),
A plurality of guide vanes (7) are arranged in an arc shape concentric with the rotation center (P) of the cross flow fan (1), and these guide vanes (7) are tangential to the air inflow side end (71). (A) passes through the rotation center (P) and intersects a cross line (B) perpendicular to the tangent line (A) with the air outflow end (7).
A cross flow fan device wherein a guide angle between the tangent (C) and 2) is set to 20 to 50 degrees.