JP2015214912A - Axial flow fan and air conditioner with axial flow fan - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an axial flow fan and an air conditioner including this axial flow fan capable of restricting reduction in air volume while restricting a leakage flow.SOLUTION: An outer circumferential end (7) of each of blades (6) in an axial flow fan (1) comprises an opposing portion (72) oppositely facing in a radial direction against a bell-mouth (3) and a suction side portion (71) positioned at an air sucking side rather than the opposing portion (72) and the bell-mouth (3). Each of blades (6) comprises a blade end plate (8) protruded to an air blowing-out side from a portion other than the suction side portion (71) at the outer circumferential end (7). The blade end plate (8) extends from a portion other than the suction side portion (71) at the outer circumferential end (7) to an end part (82) of a rear edge (10) at the outer circumferential end (7).

Description

  The present invention relates to an axial fan and an air conditioner including the same.

  Conventionally, an axial fan used for an air conditioner or the like is known. When the axial flow fan rotates, an air flow (leakage flow) is generated in the vicinity of the outer peripheral edge of the blades from the pressure surface side with high pressure to the negative pressure surface side with low pressure. When such a leakage flow occurs, the efficiency of the fan is reduced, and therefore the rotational speed of the impeller necessary for obtaining a desired air volume increases. As the rotational speed increases, the stress acting on the blade increases, so it is necessary to increase the strength of the blade so that the reliability of the blade does not decrease.

  Patent Document 1 proposes a technique for suppressing the leakage flow from the pressure surface to the suction surface by providing a rib on the pressure surface of the blade, but the effect of reducing the leakage flow is considered to be limited. .

  Patent Document 2 discloses a blower provided with a blade end plate standing on the discharge side at the outer peripheral end of a blade. Patent Document 1 describes that the provision of a blade end plate can suppress the flow of air from the pressure surface side to the suction surface side.

  Patent Document 3 discloses a blower in which a rib is attached to the pressure surface side of the outer peripheral end of a blade not surrounded by an orifice.

JP 2009-19576 A JP 2013-96307 A JP-A-5-44695

  However, the ribs and blade end plates provided on the outer peripheral ends of the blades may inhibit air from flowing into the blades, and the air volume may be reduced by providing the ribs and blade end plates. .

  An object of the present invention is to provide an axial fan and an air conditioner equipped with the axial fan that can suppress a decrease in air flow while suppressing a leakage flow.

  The axial fan of the present invention includes an impeller (2) having a plurality of blades (6), and a bell mouth (3) surrounding the impeller (2). The outer peripheral end (7) of each blade (6) is opposed to the bell mouth (3) in the radial direction (72), and more air than the facing portion (72) and the bell mouth (3). A suction side portion (71) located on the suction side. Each blade (6) includes a blade end plate (8) that protrudes from a portion other than the suction side portion (71) in the outer peripheral end (7) to the air blowing side. The blade end plate (8) extends from a portion other than the suction side portion (71) in the outer peripheral end (7) to an end portion (82) on the rear edge (10) side in the outer peripheral end (7). .

  The axial fan of the present invention is a semi-open axial fan in which the suction side portion (71) of the impeller (2) is not surrounded by the bell mouth (3). In such a semi-open type axial fan, if the blade end plate (8) is provided in the suction side portion (71) of the impeller (2), the suction side portion (71) is radially outer. The flow of air flowing into the blades (6) from the air will be obstructed.

  Therefore, in the present invention, each blade (6) includes a blade end plate (8) that protrudes from a portion other than the suction side portion (71) at the outer peripheral end (7) to the air blowing side. Thus, in this invention, since the wing | blade end plate (8) is not provided in the suction side part (71) which is not enclosed by the bell mouth (3), it is blade | wing from a radial direction outer side in a suction side part (71). (6) It does not hinder the inflow of air. Therefore, it is possible to suppress a decrease in the air volume.

  On the other hand, the blade end plate (8) extends from a portion other than the suction side portion (71) in the outer peripheral end (7) to an end portion (82) on the rear edge (10) side in the outer peripheral end (7). Therefore, the occurrence of leakage flow is suppressed on the trailing edge (10) side where the work of the blade (6) is large, that is, on the trailing edge (10) side where the differential pressure between the pressure surface and the suction surface is large and the leakage flow is likely to occur. can do. Thereby, the fall of an air volume can be suppressed, suppressing a leak flow.

  In the axial fan, the blade end plate (8) extends from the facing portion (72) to an end portion (82) on the trailing edge (10) side. In this configuration, the leakage flow from the facing portion (72) to the end portion (82) on the rear edge (10) side can be suppressed. As a specific example of such a configuration, as shown in FIG. 4A, a configuration in which the blade end plate (8) is provided only in the facing portion (72) can be mentioned.

  In the axial fan, the outer peripheral end (7) of each blade (6) further includes a blowout side portion (73) located on the air blowout side of the opposed portion (72) and the bell mouth (3). The blade end plate (8) extends from the blowout side portion (73) at the outer peripheral end (7) to the end portion (82) on the rear edge (10) side. As described above, in the blade (6) having the outer peripheral end (7) including the blowout side portion (73) located on the blowout side from the bell mouth (3), the rear edge (10) side from the facing portion (72). It is also possible to locally provide the blade end plate (8) in the blowing side portion (73) located at the position. In this configuration, since the blade end plate (8) is locally provided on the blowout side portion (73) on the trailing edge (10) side where the pressure difference between the pressure surface and the suction surface is likely to increase, a leakage flow occurs. It is possible to suppress an increase in the weight of the blade (6).

  In the axial fan, the maximum height portion (P1) of the blade end plate (8) is more than the end (81) on the front edge (9) side of the blade end plate (8). It is preferable to be provided at a position near the end (82) on the rear edge (10) side in (8). The differential pressure between the pressure surface and the suction surface tends to be greatest near the outer peripheral end (7) and near the trailing edge (10). Therefore, the maximum height portion (P1) of the blade end plate (8) is provided at a position closer to the end portion (82) on the rear edge (10) side than the end portion (81) on the front edge (9) side. Accordingly, the height (H) of the blade end plate (8) can be made to correspond to the magnitude of the differential pressure. Thereby, a leak flow can be effectively suppressed in a place where the differential pressure is large.

  In the axial fan, the height (H) of the blade end plate (8) is the portion of the maximum height from the end (81) on the front edge (9) side of the blade end plate (8) ( It is preferable that it gradually increases to P1) and gradually decreases from the maximum height portion (P1) to the end (82) on the trailing edge (10) side of the blade end plate (8). When the height (H) of the blade end plate (8) increases or decreases in this way, the turbulence of the airflow due to the provision of the blade end plate (8) can be suppressed.

  In the axial flow fan, when the end portion (81) on the front edge (9) side of the blade end plate (8) is formed by a curved surface convex toward the front edge (9), the air flow is convex. Since the airflow smoothly flows along the curved surface, the turbulence of the airflow due to the provision of the blade end plate (8) can be suppressed.

  Since the air conditioner of the present invention includes the axial fan, the reduction of the air volume is suppressed in the axial fan, and as a result, the fan input is reduced. Therefore, in the air conditioner of the present invention, power consumption can be suppressed.

  ADVANTAGE OF THE INVENTION According to this invention, the fall of an airflow can be suppressed, suppressing a leak flow.

(A) is a front view showing a schematic structure of an outdoor unit of an air conditioner including an axial fan according to an embodiment of the present invention. (B) is sectional drawing of the outdoor unit, and is a figure when the outdoor unit is viewed from above. (A) is a perspective view which shows the impeller of the axial fan which concerns on embodiment, (B) is a perspective view which shows the impeller of the axial fan which concerns on a reference example. (A) is a front view which shows the impeller of the axial fan which concerns on embodiment, (B) is the IIIB-IIIB sectional view taken on the line of (A). (A) is a schematic diagram when the axial fan according to the embodiment is viewed from the side, and (B) is a schematic diagram when the axial fan according to the reference example is viewed from the side. (A) And (B) is the pressure distribution figure of the blade surface in the impeller of the axial-flow fan of a reference example, (A) is the figure which looked at the negative pressure surface of the blade | wing from the suction side, (B) These are the figures which looked at the pressure surface of the blade | wing from the blowing side. It is a side view which shows a part of impeller of the axial fan which concerns on embodiment. It is a figure for demonstrating the relationship between the pressure distribution of a suction surface, and the position which provides a blade end plate. (A) is the figure which expanded the blade end plate provided in the blade | wing of the axial flow fan which concerns on embodiment, and its vicinity, (B) is the figure which expanded a part of (A) further. It is the figure which compared the characteristic of the axial fan which concerns on embodiment, and the characteristic of the axial fan which concerns on a reference example. (A) is the schematic which shows the modification 1 of the axial fan which concerns on embodiment, (B) is the schematic which shows the modification 2 of the axial fan which concerns on embodiment. (A) is the schematic which shows the modification 3 of the axial fan which concerns on embodiment, (B) is the schematic which shows the modification 4 of the axial fan which concerns on embodiment.

[Overall structure of air conditioner]
Hereinafter, an axial fan 1 according to an embodiment of the present invention and an air conditioner including the same will be described with reference to the drawings. FIG. 1A is a front view showing a schematic structure of an outdoor unit 90 of an air conditioner equipped with an axial fan 1 according to the present embodiment, and FIG. 1B is a cross-sectional view of the outdoor unit 90. It is a figure when the outdoor unit 90 is seen from the top. This air conditioner includes an outdoor unit 90 shown in FIG. 1 and an indoor unit (not shown). The outdoor unit 90 includes an outdoor heat exchanger 92, a compressor 93, the axial fan 1, and the like, which are accommodated in a casing 91. The indoor unit includes an unillustrated expansion mechanism, an indoor heat exchanger, and the like. The compressor 93, the outdoor heat exchanger 92, the expansion mechanism, the indoor heat exchanger, and an unillustrated refrigerant pipe connecting them constitute a refrigerant circuit of the air conditioner.

  In the outdoor unit 90 shown in FIG. 1, an outdoor heat exchanger 92 is provided on the back side of the casing 91. The casing 91 is provided with an air suction port 94 along the outdoor heat exchanger 92. An air outlet 95 is provided on the front side of the casing 91. The air outlet 95 is provided with a fan guard 95a having a grill structure. In the outdoor unit 90, the air outlet 95 may be provided in the upper part of the casing 91, for example.

[Overall structure of axial fan]
The axial fan 1 includes an impeller 2, a bell mouth 3 (duct 3), and a motor 4. In the present embodiment, the impeller 2 is supported in the casing 91 so that the rotation axis A faces in the horizontal direction, but the direction of the rotation axis A is not limited to this. The rotation axis A may be directed in a direction inclined with respect to the horizontal direction, for example. For example, when the blower outlet 95 is provided in the upper part of the casing 91, the rotating shaft A of the impeller 2 may face the up-down direction (vertical direction). The impeller 2 is connected to the shaft 4 a of the motor 4 and is rotated about the rotation axis A by the motor 4.

  A bell mouth 3 surrounding the outer periphery of the impeller 2 is provided in the casing 91. The bell mouth 3 is disposed with a small gap between the bell mouth 3 and the impeller 2 so as not to contact the impeller 2. The bell mouth 3 is an annular member along the periphery of the impeller 2, and guides the air that has passed through the outdoor heat exchanger 92 to the air outlet 95. The bell mouth 3 is provided between a region X (suction region X) on the upstream side of the air flow from the impeller 2 and a region Y (outlet region Y) on the downstream side of the air flow from the impeller 2. It has been.

  When the motor 4 is energized and the impeller 2 rotates, a pressure difference is generated between the suction region X and the blowing region Y, and an air flow from the suction region X toward the blowing region Y is formed. The outdoor air is sucked into the casing 91 from the suction port 94, exchanges heat with the refrigerant in the outdoor heat exchanger 92 when passing through the outdoor heat exchanger 92, and then blown out of the casing 91 from the outlet 95. .

[Structure of impeller]
FIG. 2A is a perspective view showing the impeller 2 of the axial fan 1 according to the present embodiment. FIG. 3A is a front view showing the impeller 2 of the axial fan 1 according to this embodiment, and FIG. 3B is a cross-sectional view taken along the line IIIB-IIIB in FIG. As shown in FIG. 2A and FIGS. 3A and 3B, the impeller 2 includes a hub 5 and a plurality of blades 6. In the present embodiment, the impeller 2 includes five blades 6, but is not limited thereto, and may include two, three, or four blades 6, and may include six or more blades 6. May be provided.

  The hub 5 has a shape such as a columnar shape (cylindrical shape) or a truncated cone shape, but is not limited thereto. The plurality of blades 6 are arranged at equal intervals along the outer peripheral surface 5 a of the hub 5. For example, in the case of the cylindrical hub 5, the outer diameter is substantially constant. However, in the case of the truncated cone-shaped hub 5, the outer diameter increases or decreases toward the rotation axis A direction. The hub 5 may have a shape such as a combination of a columnar shape and a truncated cone shape, or may have another shape. The hub 5 has an outer peripheral surface 5a to which a plurality of blades 6 are connected. The rotation axis A of the impeller 2 is located at the center of the hub 5.

  The blades 6 are radially inner (hub 5 side) edges that are connected to the hub 5, an outer circumferential edge 7 that is a radially outer edge, and a front edge in the rotational direction D. It has a certain leading edge 9 and a trailing edge 10 that is an edge on the rear side in the rotation direction D (opposite to the rotation direction D). As shown in FIG. 2A, each blade 6 has a twisted shape so that the front edge 9 is located on the entire suction region X side as compared with the rear edge 10. Each blade 6 has a pressure surface 12 facing the outlet 95 side (blowout region Y side) and a negative pressure surface 13 facing the opposite side (suction region X side). In the present embodiment, each blade 6 includes a blade end plate 8 that suppresses an air flow (leakage flow) F <b> 3 that circulates from the pressure surface 12 side to the negative pressure surface 13 side in the vicinity of the outer peripheral end 7. Details of the blade end plate 8 will be described later.

  FIG. 4A is a schematic view of the axial fan 1 according to this embodiment as viewed from the side. As shown in FIG. 4 (A), the outer peripheral end 7 of each blade 6 is positioned opposite to the bell mouth 3 in the radial direction, and is positioned closer to the air suction side than the facing portion 72 and the bell mouth 3. And a suction side portion 71. That is, the axial fan 1 of this embodiment is a semi-open axial fan in which the suction side portion 71 of the impeller 2 is not surrounded by the bell mouth 3.

  In the present embodiment shown in FIG. 4A, the bell mouth 3 has a substantially constant inner diameter. However, the present invention is not limited to this. For example, as in Modification 1 shown in FIG. The inner diameter may gradually change in the direction. In this embodiment shown in FIG. 4A, the suction side edge of the bell mouth 3 is connected to the partition plate 3A. As shown in FIG. 1B, the partition plate 3A is supported by, for example, a casing 91, a heat exchanger 92, and the like.

  FIG. 2B is a perspective view showing the impeller 102 of the axial fan 101 according to the reference example, and FIG. 4B is a schematic view of the axial fan 101 according to the reference example seen from the side. is there. The axial fan 101 according to the reference example is the same as the axial fan 101 according to the present embodiment except that the blade 106 does not include the blade end plate 8 in the present embodiment.

  The impeller 102 in the reference example includes a hub 5 and a plurality of blades 106, and an outer peripheral end 7 of each blade 106 has a facing portion 72 that faces the bell mouth 3 in the radial direction, a facing portion 72, and a bell mouth. 3 and a suction side portion 71 located on the air suction side from the third side. That is, the axial fan 101 according to the reference example is a semi-open axial fan. In this reference example, when the axial fan 101 rotates, in the vicinity of the outer peripheral end 7 of the blade 106, an air flow F3 (leakage flow F3) that circulates from the high pressure surface 12 side to the low pressure surface 13 side is generated. To do. When such a leakage flow F3 occurs, the efficiency of the fan is reduced, and the rotational speed of the impeller 102 required to obtain a desired air volume increases.

  FIGS. 5A and 5B are pressure distribution diagrams on the blade surface of the impeller 102 of the axial fan 1 of the reference example. These pressure distribution diagrams are obtained by numerical analysis. 5A is a view of the suction surface 13 of the blade 106 as viewed from the suction side, and FIG. 5B is a view of the pressure surface 12 of the blade 106 as viewed from the blowing side.

  As shown in FIG. 5A, on the negative pressure surface 13, it can be seen that the pressure in the region SA on the radially outer peripheral end 7 side and on the rear edge 10 side in the circumferential direction is the lowest. Further, as shown in FIG. 5B, on the pressure surface 12, it can be seen that the pressure in the region SB on the outer peripheral end 7 side in the radial direction and on the rear edge 10 side in the circumferential direction is highest. Therefore, in each blade 6, the pressure difference between the pressure surface 12 and the negative pressure surface 13 tends to increase in the region SA on the radial outer peripheral end 7 side and in the circumferential rear edge 10 side. As a result, in the reference example shown in FIGS. 2B and 4B, an air flow (leakage flow) F3 that circulates from the pressure surface 12 side to the negative pressure surface 13 side tends to occur in the vicinity of the outer peripheral end 7.

  Therefore, in the axial flow fan 1 according to the present embodiment, each blade 6 is provided with a blade end plate 8 as shown in FIGS. 2 (A), 3 (A), 3 (B), and 4 (A). Yes. The blade end plate 8 is provided in a portion overlapping the bell mouth 3 in the radial direction. The blade end plate 8 protrudes from the portion other than the suction side portion 71 at the outer peripheral end 7 to the air blowing side (pressure surface 12 side). As shown in FIG. 3 (B), the blade end plate 8 protrudes from the outer peripheral end 7 in the direction parallel to the rotation axis A to the blowing side (the blowing region Y side). May be inclined toward the side closer to the hub 5, or may be inclined toward the side away from the hub 5 with respect to the rotation axis A. In the present embodiment, the outer diameter of the blade end plate 8 is substantially the same as the outer diameter of the blade 6 where the blade end plate 8 is provided.

  The blade end plate 8 extends from a portion other than the suction side portion 71 at the outer peripheral end 7 to an end portion 82 on the rear edge 10 side at the outer peripheral end 7. Thus, in this embodiment, since the blade end plate 8 is not provided in the suction side portion 71 not surrounded by the bell mouth 3, air flows into the blade 6 from the radially outer side in the suction side portion 71. Does not disturb. That is, the air flow indicated by the arrow F2 in FIG. Therefore, it is possible to suppress a decrease in the air volume. In the present embodiment, the blade end plate 8 is provided on the trailing edge 10 side with respect to the center in the rotation direction D at the outer peripheral end 7.

  Further, since the blade end plate 8 extends from a portion other than the suction side portion 71 at the outer peripheral end 7 to the end portion 82 on the rear edge 10 side at the outer peripheral end 7, the rear edge 10 side where the work amount of the blade 6 is large, That is, it is possible to suppress the occurrence of leakage flow on the trailing edge 10 side where the differential pressure between the pressure surface 12 and the negative pressure surface 13 is large and leakage flow is likely to occur.

  Specifically, as shown in FIG. 4A, the blade end plate 8 extends from the facing portion 72 to the end 82 on the trailing edge 10 side. That is, the end 81 on the leading edge 9 side of the blade end plate 8 is provided in the facing portion 72, and the end 82 on the trailing edge 10 side of the blade end plate 8 is substantially the same as the trailing edge 10 in the radial direction. In the position. The blade end plate 8 is not provided on the suction side portion 71.

  The meaning that the blade end plate 8 extends to the end 82 on the trailing edge 10 side means that the position of the end 82 on the trailing edge 10 side in the blade end plate 8 is strictly the position of the trailing edge 10 in the radial direction. The position of the end portion 82 on the rear edge 10 side is radially inward with respect to the position of the rear edge 10 as long as there is substantially no influence from the viewpoint of suppressing leakage flow on the rear edge 10 side. The case where it has shifted outside is also included.

  In the embodiment shown in FIG. 4A, the blade end plate 8 is provided only in the facing portion 72 and is provided in a range that substantially matches the range of the facing portion 72, but is not limited thereto. For example, as shown in Modifications 3 and 4 shown in FIGS. 11 (A) and 11 (B) described later, when each blade 6 includes a blowout side portion 73, the blade end plate 8 has a facing portion 72 and a blowout side. It may be provided in the portion 73 (FIG. 11A), or the blade end plate 8 may be provided only in the blowing side portion 73 (FIG. 11B).

  FIG. 6 is a side view showing a part of the impeller 2 of the axial fan 1 according to the embodiment. As shown in FIG. 6, the blade end plate 8 includes a boundary portion 83 (suction-side edge portion 83) with the outer peripheral end 7 of the blade 6 and an edge portion 84 (end surface on the blowing side) opposite to the boundary portion 83. 84). As shown in FIG. 6, the boundary 83 is smoothly curved from the end 81 on the front edge 9 side to the end 82 on the rear edge 10 side. The boundary portion 83 has a convex curved shape on the suction side (the suction region X side).

  As shown in FIGS. 6, 8 </ b> A, and 8 </ b> B, the end surface 84 on the blowing side is relative to the rotation axis A from the end 81 on the front edge 9 side to the vicinity of the end 82 on the rear edge 10 side. It has an inclined end face 841 extending in the direction of inclination. Specifically, the inclined end surface 841 is inclined with respect to the rotation axis A so as to be located on the blowing side (the blowing region Y side) from the end 81 on the front edge 9 side toward the end 82 on the rear edge 10 side. ing. In the present embodiment, the inclined end surface 841 is a flat surface as a whole, but is not limited thereto. For example, the inclined end surface 841 may be a curved surface that is recessed on the suction side (the suction region X side), and on the blowing side (the blowing region Y side). It may be a convex curved surface.

  Further, in the present embodiment, as shown in FIGS. 6 and 8A, the end surface 84 on the blowing side has an orthogonal end surface 842 connected to the rear edge side end portion of the inclined end surface 841. The orthogonal end surface 842 is a plane orthogonal to the rotation axis A. The orthogonal end surface 842 extends to the end 82 on the trailing edge 10 side of the blade end plate 8. The orthogonal end surface 842 can be omitted. In this case, for example, the inclined end surface 841 extends to the end 82 on the trailing edge 10 side of the blade end plate 8.

  As shown in FIGS. 6, 8 </ b> A, and 8 </ b> B, the blade end plate 8 has an outer surface 85 and an inner surface 86 on the opposite side. The outer side surface 85 constitutes a radially outer side surface of the blade end plate 8, and the inner side surface 86 constitutes a radially inner side surface of the blade end plate 8. The blowing-side end face 84 connects the blowing-side edge of the outer face 85 and the blowing-side edge of the inner face 86. In the present embodiment, the outer surface 85 and the inner surface 86 are curved surfaces that are curved along the facing portion 72 of the outer peripheral end 7, but are not limited thereto, and may be flat surfaces, for example.

  The position (the position of the lower end portion in FIG. 6) of the blowing side (the blowing region Y side) of the blade end plate 8 is substantially the same as the position of the trailing edge 10 (the position where the trailing edge 10 and the outer peripheral edge 7 intersect). It may be the same, and as in the specific example shown in FIG. 6, it may be on the blowing side (blowing area Y side) rather than the position of the trailing edge 10 (the position of the portion where the trailing edge 10 and the outer peripheral edge 7 intersect). .

  The height H of the blade end plate 8 may be constant from the end portion 81 on the leading edge 9 side of the blade end plate 8 to the end portion 82 on the trailing edge 10 side of the blade end plate 8, but is shown in FIG. As in the embodiment, it may be changed without being constant.

  In the specific example shown in FIG. 6, the blade end plate 8 has a shape in which the height H of one part is larger than the height H of the other part. That is, the blade end plate 8 has a maximum height portion P1 having a height H higher than that of the other portions. In the present embodiment shown in FIG. 6, the maximum height portion P1 in the blade end plate 8 is an end portion 82 on the trailing edge 10 side in the blade end plate 8 rather than the end portion 81 in the blade end plate 8 on the front edge 9 side. However, the present invention is not limited to this. The maximum height portion P1 in the blade end plate 8 may be provided at a position closer to the end portion 81 on the front edge 9 side than the end portion 82 on the rear edge 10 side in the blade end plate 8.

  Further, the height H of the blade end plate 8 gradually increases from the end portion 81 on the leading edge 9 side of the blade end plate 8 to the maximum height portion P1, and the rear end of the blade end plate 8 from the maximum height portion P1. Although gradually decreasing to the end portion 82 on the edge 10 side, the present invention is not limited to this. In the present embodiment, only one portion P1 having the maximum height in the blade end plate 8 is provided, but a plurality of portions P1 may be provided. Further, the maximum height portion P <b> 1 may have a width in a direction from the end portion 81 toward the end portion 82. In the present embodiment, the height H of the blade end plate 8 (that is, the height H at an arbitrary position on the blade end plate 8) is separated from the arbitrary position of the edge portion 84 on the blowing side in the blade end plate 8 and the boundary. This is the shortest distance from the portion 83.

  The height H of the blade end plate 8 can be set based on the pressure distribution on the blade surface as shown in FIGS. 5 (A) and 5 (B), for example. Specific examples are as follows.

  FIG. 7 is a pressure distribution diagram of the suction surface 13 of the blade 6 as viewed from the suction side and a front view of the suction surface 13 of the blade 6 as viewed from the suction side. The pressure distribution of the suction surface 13 and the blade end plate 8 are provided. It is a figure for demonstrating the relationship with a position. The pressure distribution portion in FIG. 7 is the same as the pressure distribution diagram shown in FIG. 5A, and the front view in FIG. 7 is an enlarged view of part of FIG.

  As shown in FIG. 7, the blade end plate 8 is provided at a position corresponding to the area SA where the pressure is low on the suction surface 13 (area SA on the radially outer peripheral end 7 side and the circumferential trailing edge 10 side). ing. Further, as shown in FIG. 7, the maximum height portion P1 in the blade end plate 8 is an end portion 82 on the trailing edge 10 side in the blade end plate 8 rather than the end portion 81 in the blade end plate 8 on the front edge 9 side. It is provided in the position near. As shown in FIG. 7, in the area SA, the pressure in the area SA1 on the rear edge 10 side (area SA1 closer to the rear edge 10 than the front edge 9) tends to be lower than the area on the front edge 9 side. A portion P1 having the maximum height in the blade end plate 8 can be provided at a position corresponding to such a pressure distribution.

  FIG. 8A is an enlarged view of the blade end plate 8 provided on the blade 6 of the axial flow fan 1 according to the embodiment and the vicinity thereof, and FIG. 8B is a partial view of FIG. It is the figure expanded further. As shown in FIGS. 8A and 8B, it is preferable that the end 81 on the front edge 9 side of the blade end plate 8 is formed of a curved surface convex on the front edge 9 side. In this case, since the air flow indicated by the alternate long and short dash line in FIG. 8B smoothly flows along the convex curved surface, the turbulence of the air flow due to the provision of the blade end plate 8 can be suppressed.

  FIG. 9 is a diagram comparing the characteristics of the axial fan 1 according to the embodiment and the characteristics of the axial fan 101 according to the reference example. As shown in FIG. 9, the axial flow fan 1 according to the embodiment includes the blade end plate 8. Therefore, when the air volume is the same as that in the reference example, the rotational speed can be reduced, and as a result, the fan input is reduced. ing.

[Summary of Embodiment]
As described above, in the present embodiment, each blade 6 includes the blade end plate 8 that protrudes from the facing portion 72 at the outer peripheral end 7 to the air blowing side, and the blade end plate 8 extends from the facing portion 72 to the outer peripheral end. 7 to the end 82 on the trailing edge 10 side. Accordingly, it is possible to suppress the occurrence of leakage flow on the trailing edge 10 side where the work amount of the blade 6 is large, that is, on the trailing edge 10 side where the differential pressure between the pressure surface and the suction surface is large and leakage flow is likely to occur. Further, in the present embodiment, the blade end plate 8 is not provided in the suction side portion 71 not surrounded by the bell mouth 3. Therefore, since air is not inhibited from flowing into the blades 6 from the radially outer side in the suction side portion 71, a decrease in the air volume can be suppressed. Thereby, the fall of an air volume can be suppressed, suppressing a leak flow.

  In the present embodiment, the maximum height portion P1 of the blade end plate 8 is closer to the end 82 on the trailing edge 10 side of the blade end plate 8 than the end portion 81 of the blade end plate 8 on the front edge 9 side. In the position. The pressure difference between the pressure surface and the suction surface tends to be greatest in the vicinity of the outer peripheral end 7 and in the vicinity of the trailing edge 10. Therefore, the height H of the blade end plate 8 is set by providing the portion P1 having the maximum height in the blade end plate 8 at a position closer to the end portion 82 on the rear edge 10 side than the end portion 81 on the front edge 9 side. This can correspond to the magnitude of the differential pressure. Thereby, a leak flow can be effectively suppressed in a place where the differential pressure is large.

  In the axial fan, the height (H) of the blade end plate 8 gradually increases from the end 81 on the leading edge 9 side of the blade end plate 8 to the maximum height portion P1, and from the maximum height portion P1 to the blade. The end plate 8 gradually decreases to the end 82 on the rear edge 10 side. Since the height H of the blade end plate 8 increases and decreases in this way, the turbulence of the airflow due to the provision of the blade end plate 8 can be suppressed.

[Modification]
As mentioned above, although embodiment of this invention was described, this invention is not limited to these embodiment, A various change, improvement, etc. are possible in the range which does not deviate from the meaning.

  FIG. 10A is a schematic diagram illustrating a first modification of the axial fan 1 according to the embodiment. In the first modified example, the bell mouth 3 is provided on the suction side (suction region X side) of the first portion 31 (a portion having a linear cross section) having a substantially constant inner diameter and on the rotation axis A. A second portion 32 (a portion having a curved cross section) whose inner diameter changes in the direction. The second portion 32 is connected to the end of the first portion 31 on the suction side, and the inner diameter becomes smaller toward the first portion 31. In the first modification shown in FIG. 10 (A), the edge of the bell mouth 3 on the blowing side (the blowing region Y side) is connected to the partition plate 3A. However, the present invention is not limited to this, and is shown in FIG. 4 (A). The suction side edge of the bell mouth 3 may be connected to the partition plate 3A as in the embodiment.

  In Modification 1 shown in FIG. 10A, the blade end plate 8 extends from the facing portion 72 at the outer peripheral end 7 to the end 82 on the trailing edge 10 side. The blade end plate 8 is not provided in the suction side portion 71 at the outer peripheral end 7. In the first modification, the facing portion 72 includes a portion of the outer peripheral end 7 that faces the first portion 31 in the radial direction and a portion that faces the second portion 31 in the radial direction. In the specific example shown in FIG. 10A, the blade end plate 8 is provided only in the first portion 31, but is not limited thereto, and is provided in both the first portion 31 and the second portion 32. Also good.

  FIG. 10B is a schematic diagram illustrating a second modification of the axial fan 1 according to the embodiment. In the embodiment shown in FIG. 4A, the blade end plate 8 is provided in a range that substantially matches the range of the facing portion 72, but in the second modification shown in FIG. Is provided in a part of the facing portion 72 (a range smaller than the entire range of the facing portion 72). In the second modification, the end 81 on the leading edge 9 side of the wing end plate 8 is provided on the blowing side with respect to the end on the leading edge 9 side of the bell mouth 3, and the trailing edge 10 side of the wing end plate 8 is provided. The end portion 82 is provided at substantially the same position as the rear edge 10 in the radial direction.

  FIG. 11A is a schematic diagram illustrating a third modification of the axial fan 1 according to the embodiment, and FIG. 11B is a schematic diagram illustrating a fourth modification of the axial fan 1 according to the embodiment. is there. In these modified examples 3 and 4, the outer peripheral end 7 of each blade 6 in the axial fan 1 further includes a blowout side portion 73 located on the air blowing side with respect to the facing portion 72 and the bell mouth 3.

  In the third modification shown in FIG. 11A, the blade end plate 8 extends from the facing portion 72 at the outer peripheral end 7 to the end 82 on the trailing edge 10 side. In the third modification, the blade end plate 8 is provided in the facing portion 72 and the blowout side portion 73, and is not provided in the suction side portion 71.

  In Modification 4 shown in FIG. 11B, the blade end plate 8 extends from the blowing side portion 73 at the outer peripheral end 7 to the end portion 82 on the trailing edge 10 side. In the fourth modification, the blade end plate 8 is provided in the blowing side portion 73 and is not provided in the suction side portion 71 and the facing portion 72. In this modified example 4, since the blade end plate 8 is provided locally on the outlet side portion 73 on the trailing edge 10 side where the pressure difference between the pressure surface 12 and the negative pressure surface 13 tends to be large, leakage flow occurs. While suppressing, the weight increase of the blade | wing 6 can be suppressed.

  In the said embodiment, although the case where an axial flow fan was used for the outdoor unit 90 of an air conditioner was illustrated, it is not limited to this. The axial fan can be used as a fan for an indoor unit of an air conditioner, for example, and can also be used as a fan such as a ventilation fan.

DESCRIPTION OF SYMBOLS 1 Axial fan 2 Impeller 3 Bell mouth 5 Hub 5a Hub outer peripheral surface 6 Blade 7 Blade outer peripheral end 8 Blade end plate 9 Blade front edge 10 Blade rear edge 11 Blade inner peripheral end 12 Blade pressure surface 13 Blade suction surface 71 Suction side portion of outer peripheral end 72 Opposing portion of outer peripheral end 73 Outlet side portion of outer peripheral end 81 End portion on front edge side of blade end plate 82 End portion on rear edge side of blade end plate 90 Outdoor unit A Impeller Rotation axis D Impeller rotation direction P1 Maximum height of blade end plate X Suction area Y Blowout area

Claims (8)

An axial fan comprising an impeller (2) having a plurality of blades (6) and a bell mouth (3) surrounding the impeller (2),
The outer peripheral end (7) of each blade (6) is opposed to the bell mouth (3) in the radial direction (72), and more air than the facing portion (72) and the bell mouth (3). A suction side portion (71) located on the suction side of
Each blade (6) includes a blade end plate (8) protruding from the portion other than the suction side portion (71) in the outer peripheral end (7) to the air blowing side, and the blade end plate (8) An axial fan extending from a portion other than the suction side portion (71) in the outer peripheral end (7) to an end portion (82) on the rear edge (10) side in the outer peripheral end (7).   The axial fan according to claim 1, wherein the blade end plate (8) extends from the facing portion (72) to an end (82) on the trailing edge (10) side.   The axial fan according to claim 2, wherein the blade end plate (8) is provided only in the facing portion (72). The outer peripheral end (7) of each blade (6) further includes a blowout side portion (73) located on the air blowout side of the opposed portion (72) and the bell mouth (3),
The axial flow according to claim 1, wherein the blade end plate (8) extends from the outlet side portion (73) at the outer peripheral end (7) to an end portion (82) on the rear edge (10) side. fan.   The maximum height portion (P1) of the blade end plate (8) is the trailing edge of the blade end plate (8) rather than the end portion (81) on the front edge (9) side of the blade end plate (8). The axial flow fan according to any one of claims 1 to 4, wherein the axial fan is provided at a position close to an end (82) on the (10) side.   The height (H) of the blade end plate (8) gradually increases from the end on the leading edge (9) side of the blade end plate (8) to the maximum height portion (P1), The axial fan according to claim 5, wherein the axial flow fan gradually decreases from a maximum portion (P1) to an end (82) on the trailing edge (10) side of the blade end plate (8).   The end (81) on the front edge (9) side of the blade end plate (8) is configured by a curved surface convex toward the front edge (9). An axial fan described in 1.   An air conditioner provided with the axial fan of any one of Claims 1-7.