Once through fan

[0059] (Embodiment 1)

[0060] figure 1 It is an exploded cross-sectional view of the cross-flow fan according to Embodiment 1 of the present invention. figure 2 It is a cross-sectional view showing one impeller of the cross flow fan of the first embodiment. image 3 Yes figure 2 A-A cross-sectional view of the cross-flow fan. Figure 4 It is a cross-sectional view of the main part showing the connection part of the blade, the protrusion, and the reinforcing plate in the impeller of the first embodiment. Figure 5 Yes Figure 4 B-B cross-sectional view of the connection part. In addition, for documents related to prior art ( Figure 7 ~ Figure 12 ) The same structural components of the cross-flow fan are marked with the same symbols, and the description is omitted.

[0061] in Figure 1 to Figure 5 Among them, the cross-flow fan 21 has an impeller 22 in which a plurality of cylindrical blades 9 are connected in a shaft (rotating shaft 21x) direction, and end plates 3 and 4 are provided at both ends. A disc-shaped reinforcing plate 10 is provided inside the impeller 2. The outer diameter of the reinforcing plate 10 is formed to be smaller than the diameter of the inner circumference of the plurality of blades 9 arranged in a cylindrical shape (that is, the diameter of the inner end portion 9 a of the blade 9 ). The side surface of the reinforcing plate 10 and the inner ends 9 a of the plurality of blades 9 are connected by the protrusions 11. In addition, the plurality of blades 9, the reinforcing plate 10, and the protrusion 11 are integrally molded by injection molding of resin or the like. In addition, the joining structure of the respective impeller 22 and the joining structure of the impeller 22 and the end plates 3 and 4 adopt the same structure as the cross-flow fan of the prior art document, so the description thereof is omitted.

[0062] Here, mainly use Figure 4 with Figure 5 The structure of the blade 9, the reinforcing plate 10, and the protrusion 11 of the impeller 22 will be described in detail. One end 9x of the blade 9 in the axial direction of the impeller 22 (the end on the side opposite to the annular base plate 5) is radially inward from the inner end 9a of each blade 9 (toward the rotating shaft 21x The direction to go) the protrusion 11 is formed in a protruding manner.

[0063] Such as Figure 4 As shown, the protrusion 11 has a substantially triangular shape in a plan view, so that the protruding length from the inner end portion 9a of the blade 9 increases as it approaches the side surface of the reinforcing plate 10, and the protrusion length increases as it approaches the side surface of the reinforcing plate 10. Small way to form. The reinforcing plate 10 is formed in a disk shape, and is connected to the protrusion 11 on the side surface near the outer periphery thereof. In addition, the outer peripheral end of the reinforcing plate 10 is located on the radially inner side of the inner end 9a of the blade 9.

[0064] Such as Figure 5 As shown, the blade 9 has a smooth wing shape with no steps between the inner end portion 9a and the outer end portion 9c. The protrusion 11 formed to protrude radially inward from a part of the inner end portion 9a of the blade 9 has a shape that extends the shape of the wing as it is. In addition, in the impeller 22 of the first embodiment, the end surface of the end portion 9x of the blade 9 and the side surface of the reinforcing plate 10 (the inner side surface of the impeller 22) are located at the same position in the axial direction.

[0065] The cross-sectional shape of the surface perpendicular to the rotating shaft 1x of the cross-flow fan 21 in the projection 11 connecting the reinforcing plate 10 and the inner ends 9a of the plurality of blades 9 has a step 12 on the axis side of the rotating shaft 1x. This step 12 is formed on the outer surface of the protrusion 11 by the mold for injection molding as a parting line. Such as Figure 4 with Figure 5 As shown, the step 12 is formed around the outer surface of the protrusion 11 so as to extend along the outer end surface of the reinforcing plate 10.

[0066] As the step 12 of the protrusion 11 goes radially outward, the thickness (wall thickness) of the protrusion 11 and the blade 9 becomes smaller, and as the step 12 of the protrusion 11 goes radially inward, the protrusion 11 In such a way that the thickness (wall thickness) becomes larger, each blade 9 and protrusion 11 are formed.

[0067] With regard to the cross-flow fan 21 of the first embodiment configured as described above, the operation, function, and effect will be described below.

[0068] First, when constructing the impeller 22, the outer diameter of the reinforcing plate 10 is smaller than the diameter (inner circumferential diameter) of the inner end portion 9a of the blade 9, and the protrusion 11 connecting the reinforcing plate 10 and the blade 9 is provided. While ensuring the strength of the blade 9, the impeller 22 is made larger in diameter and integrally molded.

[0069] In addition, the outer diameter of the reinforcing plate 10 is smaller than the inner circumference of the blade 9, so the parting line (that is, the step 12) generated on the outer surface of the reinforcing plate 10 can be formed on the protrusion 11 during demolding during injection molding. produce. That is, in the cross-sectional shape of the protrusion 11 at the plane perpendicular to the rotation axis 1x of the cross-flow fan 21, the parting line is not the part located between the inner end 9a and the outer end 9c of the blade 9, Instead, when the mold is placed on the outer surface of the protrusion 10, a step 12 can be generated in the protrusion 11. Therefore, there is no step in the cross-sectional shape of the blade 9 (from the inner end 9a to the outer end 9c), and the inner end 9a to the outer end 9c of the blade 9 are on the pressure surface side 9p and the negative pressure surface side. There is no parting line in 9s, which can prevent air separation caused by steps. Thereby, in the cross flow fan 21 using the integrally molded impeller 22, it is possible to suppress the turbulence caused by the separation of the airflow, and it is possible to suppress the decrease in the air volume of the cross flow fan 1 and the increase in noise.

[0070] Furthermore, the blade 9 has a smooth wing shape with no steps from the inner end portion 9a to the outer end portion 9c, so the noise generated from the blade 9 can be reduced.

[0071] In addition, in the end portion 9x of the blade 9, a step 12 is formed on the outer surface of the protrusion 11 at a radially inward position than the inner end portion 9a, which is compared with the case where a step portion is formed on the outer surface of the blade 9. , It can suppress airflow peeling and reduce noise.

[0072] In addition, as the step 12 of the protrusion 11 goes radially outward, the thickness of the outer peripheral portion 11b of the protrusion 11 gradually becomes thinner, and as the step 12 goes radially inward, the inner circumference of the protrusion 11 becomes The wall thickness of the portion 11a gradually becomes thicker. Thereby, the necessary strength can be obtained at the connecting portion of the reinforcing plate 10 and the protruding portion 11 (that is, the inner peripheral side portion 11a), and at the connecting portion with the inner end portion 9a of the blade 9 (that is, the outer peripheral portion 11b), The protrusions 11 are connected along the smooth surface of the outer surface of the blade 9 in the thinned wing shape. Thereby, a step or the like is not formed in the blade 9 and the occurrence of air separation can be suppressed.

[0073] In addition, at the end 9x (on the one end side) of the plurality of blades 9 arranged in a cylindrical shape on the side opposite to the annular base plate 5 in the axial direction, the reinforcing plate 10 is connected to the inner end 9a of the blade 9 through the protrusion 11 . Accordingly, even when the height of the impeller 22 in the axial direction is longer, the cross-flow fan 21 can be configured to ensure the strength of the blades 9.

[0074] Therefore, the cross-flow fan 21 of the first embodiment can increase the diameter of the blade 9 while ensuring the strength of the blade 9, and the step 12 and the parting line are not generated in the part of the blade 9. Accordingly, in an indoor unit of an air conditioner incorporating such a cross-flow fan 21, it is possible to reduce the increase in noise caused by airflow separation as much as possible while increasing the air volume to save power.

[0075] (Embodiment 2)

[0076] Image 6 It is a figure which shows the main part of the impeller 32 which the cross flow fan 31 of Embodiment 2 of this invention has. In addition, the same components as those of the cross-flow fan 21 of Embodiment 1 described above are given the same reference numerals, and descriptions thereof are omitted.

[0077] Such as Image 6 As shown, the protrusion length of the protrusion 13 connected to the reinforcing plate 10 from the inner end 9a of the blade 9 to the radial inward direction ( Image 6 The length in the left-right direction in the middle) is formed so as to gradually decrease as it moves away from the reinforcing plate 10 in the axial direction. The axial height h of the impeller 32 of the protrusion 13 ( Image 6 The length in the vertical direction in the middle) is set to a range of 1% to 15% of the axial height H of the blade 9 (impeller 32) (that is, h/H=1% to 15%).

[0078] By setting the shape of the protrusion 13 with respect to the entire impeller 32 in this way, the strength for connecting the reinforcing plate 10 and the blade 9 can be sufficiently ensured, and the step 12 formed in the entire protrusion 13 or the protrusion 13 can be generated. The airflow peeling is suppressed to a small extent, and the turbulence at the protrusion 13 caused by the airflow peeling is suppressed. As a result, it is possible to suppress a decrease in the air volume of the cross-flow fan 31 and an increase in noise as much as possible.

[0079] In the above-mentioned embodiment, the case where the reinforcing plate has a disc shape has been described as an example, but the reinforcing plate may be formed in a ring shape.

[0080] In addition, the case where the inner side surface of the reinforcing plate 10 and the end surface of the blade 9 are located at the same position in the axial direction has been described as an example, but other various positional relationships can also be adopted. For example, as long as it is possible to realize the positional relationship where the annular base plate 5 and the reinforcement plate 10 are arranged to overlap in the axial direction when the impellers are connected to each other, in such a structure, the annular base plate 5 and the reinforcement plate The presence of 10 has little effect on air supply performance.

[0081] In addition, the parting line (step 12) may be formed on the outer surface of the protrusion, and the position where it is formed is not limited.