JP3661579B2 - Air conditioner indoor unit - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cross-flow fan used in an indoor unit of an air conditioner that performs indoor cooling or heating.
[0002]
[Prior art]
A conventional air conditioner has a shape as shown in FIG. 6 as described in JP-A-9-1000079. The cross-flow fan 1 is divided into a plurality of blocks partitioned by a disc 2, and has a portion in which the outer diameter of the blade 3 of at least one block changes between the discs of the block, and is adjacent to the at least one block The blade outer diameter in the adjacent part of the block to be made is different.
[0003]
A conventional air conditioner has a shape as shown in FIG. 7 as described in JP-A-10-77788. A plurality of blades 3 are arranged annularly at a predetermined mounting pitch in the circumferential direction between a pair of disk-like or annular end plates 2-1, 2-2, and are fixed in a transverse manner. An end plate 2 is disposed. Both end portions in the axial direction of the blade 3 are formed as widened portions Lb and Lc having a long chord length, while an intermediate portion La in the axial direction is integrally coupled to a chord width portion La having a short chord length.
[0004]
And the thickness distribution of these blade shapes is classified into the following two types. First, the wall thickness is constant from the leading edge to the trailing edge. Second, the maximum thickness position is in the middle between the leading edge and the trailing edge.
[0005]
[Problems to be solved by the invention]
However, in the fan blade of the first conventional example, the length of the blade is different when a load is applied (for example, when dust adheres to the air cleaning filter), the two-dimensional flow is likely to be disrupted. Therefore, especially in the vicinity of the side wall portion, the two-dimensional flow is likely to be disrupted, and an intermittent abnormal sound of “bazabasa” is generated, which is extremely uncomfortable. Furthermore, when the load is applied, the air blowing performance is significantly deteriorated, so that the cooling capacity or the heating capacity is lowered.
[0006]
The blade of the fan of the second conventional example has the same problem. In addition, as is apparent from the flow velocity vector of the blowing portion having the conventional blade shape shown in FIG. 8, it can be seen that the flow is separated at the leading edge portion and turbulence is generated. The present invention solves such a conventional problem, and as a method of giving the blade-shaped thickness distribution of the cross-flow fan, by placing the maximum thickness position inside from the center, even when a load is applied, A stable flow field can be formed.
[0007]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention provides an air conditioner including a cross-flow fan in which a plurality of blades are arranged annularly in a circumferential direction as a blower fan of an indoor unit, wherein the blade shape of the cross-flow fan is set to a maximum thickness position. Is provided at a position 4% from the inner side (inner diameter side) of the chord length of the blade, and the thickness of the blade is gradually reduced from the maximum thickness position toward both ends of the blade. It is.
[0009]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
[0010]
FIG. 1 is a cross-sectional view of a crossflow fan mounted on an indoor unit of an air conditioner and an enlarged view of one blade of the crossflow fan in the first embodiment of the present invention. The chord length of the blade is represented by line segment IO. The blade shape is characterized in that the maximum thickness position is disposed inside the center of the line segment.
[0011]
FIG. 2 shows the result of analyzing the PQ characteristics by changing the maximum wall thickness position from 2% to 60% from the inside of the chord length. The slope at the open point represents the level of static pressure. The relationship between the inclination and the thickness distribution position is shown in FIG. From this, the peaks where the static pressure increases are in the vicinity of 4% and 20%, and the static pressure tends to increase as the maximum thickness position moves to the inner peripheral side. Therefore, it can be seen that a high static pressure can be stably obtained when the maximum thickness position is 2% to 35%. Furthermore, the air volume performance per noise is shown in FIG. As a result, the maximum thickness position is almost stable in the region of 2% to 35% from the inside of the chord length. Here again, it can be seen that the airflow performance per noise is stable if the maximum thickness position is at a position of 2% to 35% inside the center.
[0012]
As shown in FIG. 5, the flow separation at the leading edge is reduced, as shown in the flow velocity vector of the blowing portion according to the blade shape of the present embodiment, and a smooth flow is generated and the air flow performance is improved. I was able to.
[0013]
【The invention's effect】
As is clear from the above-described embodiment, since the static pressure is increased, abnormal noise such as rustling is unlikely to occur even when a load is applied to the air conditioner body. Further, when the flow state is analyzed by focusing on the blowing portion during cooling and heating, the separation of the flow at the front edge portion is reduced and the air flow performance is improved. Moreover, since it expands gradually from the shortest distance between blades to a blowing part, trailing edge peeling reduces and air volume performance improves.
[0014]
From the above situation, the turbulence component is reduced and the noise is also reduced, and the air volume performance per the same noise is improved. In addition, the pressure near the open point will increase, and when applied to air conditioners, etc., heat exchanger dew will be generated during cooling, and dust will adhere to the filter (buzzing sound). Can be suppressed.
[Brief description of the drawings]
FIG. 1 is a sectional view showing an embodiment of the present invention and an enlarged view of one blade. FIG. 2 is a PQ characteristic diagram. FIG. 3 is a diagram showing the relationship between the level of static pressure and the thickness distribution position. FIG. 4 is a diagram showing air volume performance per noise. FIG. 5 is a flow velocity vector diagram of a blade blowing portion according to an embodiment of the present invention. FIG. 6 is a front view of a conventional cross-flow fan. FIG. 8 Flow velocity vector diagram of conventional blade blowing part
1 Cross-flow fan 2 Disc 3 Blade

Claims (1)

In an air conditioner having a cross-flow fan in which a plurality of blades are arranged annularly in the circumferential direction as a blower fan for an indoor unit, the blade shape of the cross-flow fan is set at the maximum thickness position inside the chord length of the blade (inner diameter side) The air conditioner indoor unit is characterized in that the blade thickness is gradually reduced from the maximum thickness position toward both ends of the blade.

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