CN106104005A

CN106104005A - Air-blast device

Info

Publication number: CN106104005A
Application number: CN201580015053.3A
Authority: CN
Inventors: 近藤广幸; 中村隆; 中村隆一; 丸山泰二
Original assignee: Panasonic Intellectual Property Management Co Ltd
Current assignee: Panasonic Intellectual Property Management Co Ltd
Priority date: 2014-03-25
Filing date: 2015-03-05
Publication date: 2016-11-09
Anticipated expiration: 2035-03-05
Also published as: JP2015194147A; CN106104005B; JP6405529B2; SA516371879B1; WO2015146007A1

Abstract

Air-blast device possesses blade (1), and this blade (1) has: the arcus part (18) heaved to the rotary shaft direction upstream side of blade (1) from blade inlet edge (8) to trailing edge (17) and the bucket front (19) configuring along blade inlet edge (8).Additionally, bucket front (19) possesses downstream at the downstream face (20) of blade (1) from blade inlet edge (8) and peels off suppressing portion (68), and this downstream is peeled off suppressing portion (68) and included: by the prominent protuberance (22) of big the first circular arc (21) of ratio of curvature arcus part (18) and the depressed part (24) to be formed in the way of adjacent with trailing edge (17) side of protuberance (22).Additionally, bucket front (19) possesses upstream side at the upstream face (25) of blade (1) from blade inlet edge (8) and peels off suppressing portion (69), and this upstream side is peeled off suppressing portion (69) and included: be formed with the end (27) of big the second circular arc (26) of ratio of curvature arcus part (18) and the groove portion (28) being formed in trailing edge (17) side of end (27).

Description

Air blower

Technical Field

The present invention relates to a blower device used in an air conditioner, a ventilation fan, or the like.

Background

Conventionally, as such an air blowing device, an air blowing device is known in which a local thickness of a blade is rapidly increased to suppress separation of an air flow and improve aerodynamic characteristics and noise characteristics (for example, see patent document 1).

The air blowing device will be described below with reference to fig. 14.

As shown in a cross-sectional view in the rotational direction of the blade 101 of the axial-flow impeller in fig. 14, a rib 102 extending along a leading edge 103 in the rotational direction of the blade 101 is provided on the negative pressure side surface of the blade 101.

Due to the rib 102, the region 104 shown on the rear side of the rib 102 generates an in-plane vortex. The surface vortex adheres to the surface 105 on the upstream side in the rotation axis direction of the blade 101, and therefore the airflow 106 is less likely to peel off from the blade 101, and the air blowing performance and the noise performance are improved.

However, in the above-described conventional blower device, since the wall thickness of the portion where the rib 102 is provided is rapidly increased compared to other portions, thermal shrinkage is likely to occur during molding, and stable molding is difficult.

Prior art documents

Patent document

Patent document 1: japanese Kokai publication Hei-5-69400

As described above, the conventional blower device has a problem that improvement in blowing performance and noise performance and stability of molding are simultaneously achieved.

Disclosure of Invention

Accordingly, the present invention provides an air blowing device that has stability of molding and does not deteriorate air blowing performance and noise performance even if a turbulent air flow flows into an impeller.

An air blowing device according to an aspect of the present invention includes: an impeller in which a plurality of blades are fixed to the outer periphery of a hub; a motor that rotates the impeller; and a frame supporting the motor. Further, the air blowing device includes: an arc-shaped portion that bulges upstream in the direction of the rotation axis of the blade from the blade leading edge to the blade trailing edge of the blade, and a blade front portion that is arranged along the blade leading edge. Further, the blade front portion includes a downstream-side separation suppressing portion on a surface of the blade on a downstream side in a rotation axis direction from a blade leading edge, and the downstream-side separation suppressing portion includes: the blade includes a protruding portion protruding in a first arc having a curvature larger than that of the arc portion, and a recessed portion formed adjacent to the blade trailing edge side of the protruding portion. Further, the blade front portion includes an upstream-side separation suppressing portion on a surface of the blade on an upstream side in a rotation axis direction from a blade leading edge, and the upstream-side separation suppressing portion includes: the blade has a second arc end portion having a curvature larger than that of the arc portion, and a groove portion formed on the blade trailing edge side of the end portion.

This makes it possible to provide an air blowing device that has stability of molding and does not deteriorate air blowing performance and noise performance even when turbulent air flows into the impeller.

Drawings

Fig. 1 is a schematic cross-sectional view of a blower according to an embodiment of the present invention.

Fig. 2 is a plan view of a blade of the air blowing device according to the embodiment of the present invention, as viewed from an upstream side in the rotation axis direction.

Fig. 3 is a sectional view taken along line 3-3 of fig. 2.

Fig. 4 is a schematic cross-sectional view showing a striped wind speed distribution region generated on the downstream side of the cover of the blower according to the embodiment of the present invention.

Fig. 5 is a schematic plan view showing a relationship between a blade leading edge of a blade of a blower device according to an embodiment of the present invention and a longitudinal direction of a wire member of a shroud.

Fig. 6A is a cross-sectional view in the rotational direction schematically illustrating separation of the airflow from the blades of the blower device according to the embodiment of the present invention.

Fig. 6B is a cross-sectional view in the rotational direction schematically showing the separation of the airflow from the blades of the blower device according to the embodiment of the present invention.

Fig. 7 is a cross-sectional view schematically showing the rotational direction of the vortices of the airflow generated in the downstream-side separation suppressing portion and the upstream-side separation suppressing portion of the blade of the air blowing device according to the embodiment of the present invention.

Fig. 8 is a cross-sectional view schematically showing the rotation direction of the airflow flowing on the downstream side in the rotation axis direction of the blades of the blower according to the embodiment of the present invention.

Fig. 9 is a cross-sectional view schematically showing the airflow flowing on the upstream side in the rotation axis direction of the blades of the blower according to the embodiment of the present invention.

Fig. 10 is a plan view of one blade of the air blowing device according to the embodiment of the present invention as viewed from above.

Fig. 11 is a perspective view of a blade in a case where a rectifying plate is disposed in a blowing device according to an embodiment of the present invention.

Fig. 12 is a cross-sectional view schematically showing a rotation direction of an air flow flowing on a negative pressure surface side of a blade in a case where a rectifying plate is arranged on the blade of the blower according to the embodiment of the present invention.

Fig. 13 is a cross-sectional view of a blowing device according to an embodiment of the present invention in the rotation direction of blades.

Fig. 14 is a cross-sectional view showing the rotation direction of blades of an impeller of a conventional air blowing device.

Detailed Description

(embodiment mode)

Hereinafter, a blower according to an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a schematic sectional view of the blower device.

As shown in fig. 1, air blowing device 90 includes: an impeller 3 having four blades 1 fixed to the periphery of a hub 2, a motor 4 connected to the downstream side of the impeller 3 and rotating the impeller 3 about a rotation shaft 7, and a frame 5 supporting the motor 4.

The blower device 90 includes a cover 51, and the cover 51 is partially connected to the frame 5 on the upstream side in the air flow direction of the impeller 3.

The cover 51 is housed in the wall to reduce the overall thickness of the blower 90, and is disposed close to the impeller 3 to reduce the protruding thickness of the cover protruding into the room to improve the interior decoration. The cover 51 is provided with an opening 52, and when the cover 51 is attached to the frame 5, air is taken into the blower 90 from the outside through the opening 52. A plurality of wire members 53 are arranged in the opening 52 to divide the opening 52. Thereby, it is difficult to directly see the impeller 3 from the outside of the air blowing device 90 to improve the appearance of the air blowing device 90.

Next, the structure of the blade 1 of the air blowing device 90 will be described in detail with reference to fig. 2 and 3. Fig. 2 is a plan view of the blade 1 as viewed from the upstream side in the rotation axis direction. Fig. 3 is a 3-3 cross-sectional view of a cross section of the blade 1 cut along the broken line 60a-60b in fig. 2, as viewed from the radially outer side in the direction toward the rotary shaft 7 (the direction of arrow 64).

As shown in fig. 2, the vane 1 rotates in the direction indicated by an arrow 65 with the rotation shaft 7 as the center, that is, counterclockwise when viewed from the upstream side of the airflow. In fig. 2, the end of the blade 1 in the direction of the rotation axis 7, that is, the contact portion with the hub 2 is referred to as a blade root 66. Further, an end portion in the outer circumferential direction of the blade 1 is referred to as a blade end 67. An upstream end of the blade 1 in the rotation direction is referred to as a blade leading edge 8, and a downstream end is referred to as a blade trailing edge 17.

As shown in fig. 2 and 3, the blade 1 has an arc-shaped portion 18 that bulges upstream in the direction of the rotation axis of the blade 1 from the blade leading edge 8 to the blade trailing edge 17. Further, the blade 1 includes a blade front portion 19 arranged along the blade leading edge 8 in a range from the blade root 66 to the blade end 67.

As shown in fig. 3, a downstream-side separation suppressing portion 68 is provided on the downstream side in the rotation axis direction of the blade front portion 19. The downstream-side peel inhibiting portion 68 includes: a protruding portion 22 in which a first arc 21 having a curvature larger than that of the arc portion 18 protrudes from the blade leading edge 8 toward the downstream surface 20 side, and a recessed portion 24 formed adjacent to the blade trailing edge 17 side of the protruding portion 22. The recessed portion 24 is connected to the downstream surface 20 of the arc portion 18 on the blade trailing edge 17 side of the protruding portion 22, and is formed by generating an inflection point due to a difference in curvature between the first arc 21 of the protruding portion 22 and the arc of the arc portion 18.

As shown in fig. 3, an upstream-side separation suppressing portion 69 is provided on the upstream side of the blade front portion 19 in the rotation axis direction. The upstream-side peel inhibiting portion 69 includes: the second arc 26 having a curvature larger than that of the arc 18 includes an end portion 27 formed to project toward the upstream surface 25 from the blade front edge 8 as a base point, and a groove portion 28 formed on the blade rear edge 17 side of the end portion 27. The end portion 27 is provided with the second arc 26 on the blade leading edge 8 side and the surface 70 on the blade trailing edge 17 side. The surface 70 is formed parallel to the rotary shaft 7 and the blade leading edge 8 from an upstream end 71 to a downstream end 72 of the end 27. In other words, the end portion 27 is formed to stand at a position on the upstream side in the rotation axis direction from the upstream surface 25 in the rotation axis direction by the structure of the surface 70.

Further, a concave portion is provided from the downstream end portion 72 so as to be recessed inward of the protruding portion 22 (upstream side in the rotation axis direction). The concave portion is connected to the upstream surface 25 at a connection point 73 on the blade trailing edge 17 side. The groove 28 is a space formed by the upstream end 71, the surface 70, the downstream end 72, and the connection point 73.

As an example of the above configuration, in the present embodiment, the diameter of the impeller 3 is set to 86mm, and the ratio of the curvature of the first arc 21 and the second arc 26 having the same curvature with the radius of 25mm to the curvature of the arc portion 18 is set to 42: 1. The curvatures of the first arc 21 and the second arc 26 are set to be the same so that the protrusion 22 and the end 27 are smoothly connected to the blade front edge 8, and the diameters of the first arc 21 and the second arc 26 are set to be 2.9 times the maximum blade thickness of the arc 18. The bottom surface (concave portion) of the groove portion 28 is formed in a semicircular shape, and the radius thereof is 34% of the first arc 21.

Next, the relationship between the speed of the airflow and the angle of the blade in the air blowing device according to the present embodiment will be described with reference to fig. 4 to 6. Fig. 4 is a schematic cross-sectional view showing a striped wind velocity distribution region generated on the downstream side of the shroud. Fig. 5 is a schematic plan view showing a relationship between a blade leading edge of the blade and a length direction of a wire member of the shroud. Fig. 6A is a cross-sectional view in the rotational direction schematically showing the separation of the airflow from the blade in the case where the direction of the airflow flowing into the blade is close to the rotational axis direction. Fig. 6B is a cross-sectional view in the rotational direction schematically showing the separation of the airflow from the blade in the case where the direction of the airflow flowing into the blade is close to the rotational direction.

When the impeller 3 is rotated by the motor 4, air is drawn into the frame 5 from the outside (upward in fig. 4) through the opening 52 of the shroud 51 by the action of the air swept by the blades 1. The sucked air is discharged to the outside (downward in fig. 4) through the impeller 3. Since the plurality of wire members 53 are arranged in the opening 52, air is sucked into the frame 5 through the gaps 54 of the wire members 53. In other words, the opening 52 is constituted by the plurality of gaps 54.

Since the airflow cannot pass through the wire member 53, the wind speed on the downstream side of the wire member 53 is slower than the wind speed on the downstream side of the gap 54. Therefore, a striped wind speed distribution region 56 (a region surrounded by a broken line in fig. 4) in which wind speeds are distributed in stripes is formed on the downstream side of the cover 51. Since the impeller 3 is provided close to the shroud 51, the impeller 3 rotates in the striped wind speed distribution region 56. In other words, when the impeller 3 rotates downstream in the striped wind speed distribution region 56, it can be said that the cover 51 is close to the impeller 3. The cover 51 is located at a very long distance from the impeller 3, and cannot be said to be close to each other in a state where the downstream wind speed is not affected by the wire member 53, in other words, if the impeller 3 rotates in a region where the wind speed is not distributed.

However, as shown in fig. 5, a plurality of wire members 53 are arranged in a row on the cover 51. On the other hand, the blade 1 rotates counterclockwise about the rotation shaft 7 as an axis. Therefore, the angle θ formed by the blade leading edge 8 of the blade 1 and the longitudinal direction of the wire member 53 can be in the range of 0 to 90 degrees.

When the angle θ is small, the entire range of the blade leading edge 8 from the blade root 66 to the blade tip 67 passes through a region where the wind speed is high or a region where the wind speed is low in the striped wind speed distribution region 56.

On the other hand, when the angle θ is large, some part of the blade leading edge 8 passes through a region where the wind speed is low, and the other part passes through a region where the wind speed is high.

Here, in the case of passing through a region where the wind speed is high, as shown in fig. 6A, the component 80 toward the downstream side in the rotation axis direction is larger than the rotation direction component 81 with respect to the wind speed component of the airflow. The inflow angle of the airflow in this state is set to an angle in the direction of approaching the rotation axis with respect to the blade.

In the case of passing through a region where the wind speed is low, as shown in fig. 6B, the component 82 toward the downstream side in the rotation axis direction is smaller than the rotation direction component 83 with respect to the wind speed component of the airflow. The inflow angle of the airflow in this state is set to an angle close to the rotation direction of the blade.

The airflow toward the blade 1 has a plurality of states of an inflow angle in fig. 6A, an inflow angle in fig. 6B, or an inflow angle (intermediate angle) in a range from fig. 6A to 6B, depending on the angle θ.

In other words, due to the shape of the shroud 51, at a certain moment, the angle at which the airflow flows into the blade 1 matches the angle of the blade 1, and no separation of the airflow from the blade 1 occurs, but at most other times, a mismatch occurs, and thus airflow separation occurs.

Therefore, when the direction of the airflow flowing into the blade 1 varies, it is very difficult to make the inflow angle of the airflow and the angle of the blade 1 uniform so as not to cause separation of the airflow from the blade 1. Peeling of the airflow from the blade 1 occurs due to such an angle inconsistency. The airflow separation is an important factor that degrades the blowing performance and deteriorates the noise performance, and therefore it is necessary to suppress the airflow separation. In fig. 6, the tip end of the blade 1 is formed in a straight shape for easy understanding, but the shape of the blade 1 used in the present embodiment is the shape shown in fig. 3.

Next, the operation of the blade front portion 19 will be described in detail with reference to fig. 7 to 9. Fig. 7 is a cross-sectional view schematically showing the swirling direction of the airflow generated by the downstream-side separation preventing section 68 and the upstream-side separation preventing section 69. Fig. 8 is a cross-sectional view schematically showing the rotational direction of the airflow flowing on the downstream side in the rotational axis direction of the blade 1. Fig. 9 is a cross-sectional view schematically showing the rotational direction of the airflow flowing on the upstream side in the rotational axis direction of the blade 1.

As shown in fig. 7, in the present embodiment, a downstream side separation suppressing portion 68 and an upstream side separation suppressing portion 69 are disposed in the blade front portion 19 of the blade 1.

When the airflow passes through the recessed portion 24 of the downstream peeling prevention portion 68, the vortex 32 of the airflow is generated due to the recessed shape of the recessed portion 24. When the airflow passes through the groove 28 of the upstream-side separation suppressing portion 69, the vortex 35 of the airflow is generated due to the depression of the groove 28.

When the direction of the airflow flowing into the blade 1 does not match the angle of the blade 1, the direction of the rotation of the airflow vortex 32 and the airflow vortex 35 away from the blade 1 can be turned by the airflow vortex 32 and the airflow vortex 35 to face the blade surface. In other words, the peeling of the airflow from the blade 1 can be suppressed.

Further, since vortices are generated on both the upstream side and the downstream side of the blade 1, the direction of the airflow flowing into the blade 1 can be changed in either a direction approaching the rotation axis of the impeller 3 (corresponding to fig. 6A) or a direction approaching the rotation axis (corresponding to fig. 6B).

In other words, as shown in fig. 8, the downstream side peel inhibiting portion 68 is provided with the recessed portion 24 so as to be adjacent to the blade trailing edge 17 side of the protruding portion 22. Therefore, the airflow flowing along the protruding portion 22 is turned in the direction of the downstream surface 20 of the blade 1 due to the sharp increase in the flow path at the recessed portion 24, and a vortex 32 of the airflow is formed in the recessed portion 24.

The vortex 32 of the airflow is a vortex that rotates in the clockwise direction when viewed from the blade end 67 side (the forward direction in fig. 8). When the airflow flowing into the blade 1 approaches the rotation axis direction of the impeller 3, the direction of the airflow to be separated from the blade front portion 19 of the blade 1 is turned toward the direction of the rotation direction of the vortex 32 of the airflow due to the viscosity of the air. The airflow adheres to the downstream surface 20 of the blade 1 and flows along the downstream surface 20.

As shown in fig. 9, the upstream-side separation suppressing portion 69 is provided with a groove 28 on the blade trailing edge 17 side of the end portion 27. Therefore, the airflow flowing along the end portion 27 is turned in the direction of the upstream surface 25 of the blade 1 by the rapid increase in the flow path in the groove portion 28, and the vortex 35 of the airflow is formed in the groove portion 28.

The vortex 35 of the airflow is a vortex that rotates in the counterclockwise direction when viewed from the blade end 67 side (the forward direction in fig. 9). When the airflow flowing into the blade 1 approaches the rotation direction of the impeller 3, the direction of the airflow to be separated from the blade front portion 19 of the blade 1 is turned toward the rotation direction of the vortex 35 of the airflow due to the viscosity of the air. The airflow adheres to the upstream surface 25 of the blade 1 and flows along the upstream surface 25.

In this way, by providing the downstream side separation suppressing portion 68 and the upstream side separation suppressing portion 69, separation of the airflow from the blade 1 is suppressed, and the air blowing device can be provided without lowering the air blowing performance and the noise performance.

The upstream-side peel inhibiting portion 69 and the downstream-side peel inhibiting portion 68 are formed by a combination of the shapes of the projections and recesses, that is, a combination of the recesses such as the recessed portion 24 and the groove portion 28 and the projections such as the projecting portion 22 and the end portion 27.

Therefore, the blade front portion 19 and the arcuate portion 18 can have the same thickness. In other words, the end portion 27 protruding upstream, the groove portion 28 recessed toward the downstream side on the blade trailing edge 17 side of the end portion 27, the protrusion 22 protruding toward the downstream side on the downstream side of the groove portion 28, and the recessed portion 24 recessed toward the upstream side on the blade trailing edge 17 side of the protrusion 22 are arranged in this order from the blade leading edge 8 side. Thereby, the blade front portion 19 can be formed with the same thickness as the thickness of the arc portion 18.

Thus, since it is not necessary to provide a thick portion for suppressing the air flow separation, the deformation due to the thermal shrinkage during the molding can be suppressed, and the molding stability can be improved. The blade 1 is formed in a curved shape including an arc portion 18, a protruding portion 22 protruding in a first arc 21, and an end portion 27 protruding in a second arc 26. Since the curved blade 1 is connected to the hub 2, the area of the portion of the blade root 66 connected to the hub 2 is increased, that is, the connection strength is increased, and the resistance to deformation can be increased.

The end portion 27 stands up at a position on the upstream side in the rotation axis direction from the upstream surface 25.

Thus, the groove 28 is shaded from the end 27 with respect to the air flow, and therefore the air flow flows into the end 27 before flowing into the groove 28. When the air directly flows into the groove 28, the air flow cannot flow from the groove 28 to the downstream surface 20, and the resistance to the flow increases. However, by first flowing into the groove portion 28, the airflow can be more easily made to flow along the end portion 27 and the protruding portion 22 toward the downstream surface 20. Further, the downstream peeling inhibitor 68 can cause the airflow to flow along the downstream surface 20. This can suppress an increase in flow resistance.

(modification example)

In a modification of the embodiment of the present invention, the same components as those in the embodiment are denoted by the same reference numerals, detailed description thereof is omitted, and only different points will be described. Fig. 10 is a plan view of one blade of the air blowing device according to the modification of the embodiment of the present invention as viewed from above.

As shown in fig. 10, the vane 1a may be configured by a vane inner peripheral portion 12 and a vane outer peripheral portion 16. In the blade leading edge 8 of the blade inner peripheral portion 12, a radial component 11 of the blade leading edge 8 is larger than a tangential rotational component 10 with respect to a component of an orientation of a tangential line (arrow 9) of the blade leading edge 8 in a plan view. In the blade leading edge 8 of the blade 1a in the blade outer peripheral portion 16, the component 15 in the rotational direction of the blade leading edge 8 is larger than the component 14 in the radial direction of the tangential line (arrow 13) with respect to the component in the direction of the tangential line in the plan view of the blade leading edge 8. The upstream-side separation suppressing portion 69 and the downstream-side separation suppressing portion 68 are provided only in the blade inner peripheral portion 12.

The blade front portion 19 shown in fig. 2 and 3 has an increased surface area and increased resistance to flow by forming the protruding portion 22 and the end portion 27. Further, since the circumferential speed of the blade outer circumferential portion 16 is higher than that of the blade inner circumferential portion 12, the influence of the increase in resistance becomes large. However, as in the modification shown in fig. 10, the protrusion 22 and the end 27 are provided only in the blade inner peripheral portion 12, and therefore an increase in resistance to flow can be suppressed.

Further, the upstream-side separation suppressing portion 69 and the downstream-side separation suppressing portion 68 may be provided only in the blade inner peripheral portion 12, and the upstream-side separation suppressing portion 69 and the downstream-side separation suppressing portion 68 may gradually disappear from the blade inner peripheral portion 12 to the blade outer peripheral portion 16 with the connecting portion 77 between the blade inner peripheral portion 12 and the blade outer peripheral portion 16 being an end point of the disappearance.

With this configuration, a sudden shape change from the blade inner circumferential portion 12 to the blade outer circumferential portion 16 in the blade front portion 19 can be reduced. This can suppress the separation of the air flow caused by the abrupt shape change.

As shown in fig. 11, a flow regulating plate 36 for partitioning the groove 28 may be provided. Specifically, as shown in fig. 12, a plurality of flow straightening plates 36 are provided along the groove portions 28 in the radial direction of the impeller 3, and the flow straightening plates 36 are formed in a semicircular plate shape having the same curvature as the second circular arc 26 of the vane front portion 19.

Thus, the airflow flowing through the upstream surface 25 flows while adhering to the flow rectification plate 36. Then, when the direction of the airflow flowing into the blade 1 changes to be close to the rotational direction, the airflow flows while adhering to the flow rectification plate 36 due to the coanda effect in addition to the separation suppressing action by the swirl 35 of the airflow. This can further suppress the airflow separation.

As shown in fig. 13, the end 27a may be provided with the second arc 26 on the blade leading edge 8 side and the surface 70a on the blade trailing edge 17 side. The surface 70a is formed to be inclined toward the blade leading edge 8 side from the upstream end 71a to the downstream end 72 of the end 27a with respect to the rotation axis direction. The upstream end 71a is rounded to have a larger curvature than the second arc 26. Further, a concave portion is provided from the downstream end portion 72a so as to be recessed inward of the protruding portion 22. The concave portion is connected to the upstream surface 25 at a connection point 73 on the blade trailing edge 17 side. The groove 28a is a space formed by the upstream end 71a, the surface 70a, the downstream end 72a, and the connection point 73.

In this way, the swirl 35a of the airflow is generated at a position closer to the blade leading edge 8. The airflow to be separated from the vane front portion 19 is turned by the swirl 35a of the airflow and adheres to the upstream surface 25. At this time, the swirl 35a of the airflow is generated at a position closer to the blade front edge 8 side, and therefore the airflow can be diverted at an initial stage of separation from the blade front portion 19. The airflow can be diverted at an initial stage, and thus separation of the airflow from the blade 1 can be further suppressed.

In the air blowing device, when the air flows into the blade at different angles with respect to the rotation axis, the downstream-side separation suppressing portion may generate an eddy in the recessed portion by the protruding portion and the recessed portion when the blade rotates, thereby suppressing separation of the air flow from the surface on the downstream side in the rotation axis direction of the blade, which is generated when the air flow flows into the blade at an angle close to the rotation axis direction. Further, the upstream-side separation suppressing portion may generate a vortex in the groove portion by the end portion and the groove portion when the blade rotates, and suppress separation of the airflow from the surface on the upstream side in the rotation axis direction of the blade, which is generated when the airflow flows in at an angle close to the rotation direction with respect to the blade.

In this way, the vortex of the airflow can be generated in the recessed portion by the protruding portion and the recessed portion, and the vortex of the airflow can be generated also in the groove portion by the end portion and the groove portion. Thus, even when the air flows into the blades at different angles with respect to the rotation axis, the air flow separation can be suppressed. In other words, in both the case where the airflow flows in the direction approaching the rotation axis with respect to the blades and the case where the airflow flows in the direction approaching the rotation direction with respect to the blades, the direction of the airflow to be separated from the blades can be turned toward the direction of the rotation of the vortex, and the separation of the airflow is less likely to occur. This reduces the air flow loss and noise.

In the air blowing device, a cover having an opening for sucking air from the outside and having a plurality of wire members arranged to partition the opening may be disposed on the upstream side of the impeller so as to be close to the impeller.

In this way, the entire thickness can be reduced, and therefore, the thickness of the projection projecting into the room can be reduced or the projection can be housed in the wall. In addition, the impeller can be shielded to improve the appearance.

In addition, the blower may be configured such that the blade includes: the blade front edge includes a blade inner circumferential portion in which a radial component of an orientation of a tangent line in a plan view is larger than a rotation direction component, and a blade outer circumferential portion in which the rotation direction component is larger than the radial component, and the blade front edge includes an upstream-side separation suppressing portion and a downstream-side separation suppressing portion only in the blade inner circumferential portion.

The front portion of the blade increases the surface area by forming the protrusion and the end portion, and resistance to flow increases. Further, since the peripheral speed of the blade outer peripheral portion is faster than the blade inner peripheral portion, the influence of the increase in resistance becomes large. However, according to this aspect, since the protruding portion and the end portion are provided only in the inner peripheral portion of the blade, an increase in resistance to the flow can be suppressed.

The air blowing device may have an end portion that is raised at a position upstream of the surface of the blade in the rotation axis direction of the impeller.

When the air flow is turbulent and flows at an angle close to the rotation axis direction of the impeller, the end portion becomes a wall when viewed from the groove portion, and the groove portion enters a shadow of the end portion with respect to the flow. Therefore, the air flow flows into the end portion before flowing into the groove portion. In other words, when the air directly flows into the groove portion, the air cannot flow from the groove portion to the downstream surface, and therefore the resistance to the flow increases. This can suppress an increase in resistance to flow.

In the blower device, a plurality of flow regulating plates may be provided in front of the blades so as to partition the groove, and the flow regulating plates may be formed in a semicircular plate shape having the same curvature as the second circular arc.

In this way, in addition to the effect of suppressing the separation by the vortex generated in the groove portion, the airflow flows while adhering to the rectifying plate due to the coanda effect, and therefore the separation of the airflow can be suppressed.

Industrial applicability

The blower device according to the present invention is expected to be applied to a blower device for indoor ventilation which requires a blowing capability and quietness.

Description of the reference numerals

1. 1a, 101 blade

2 wheel hub

3 impeller

4 electric motor

5 frame

7 rotating shaft

8 blade leading edge

9. 13, 64, 65 arrows

10. 15, 81, 83 rotation direction component

11. 14 radial component

12 inner peripheral part of blade

16 blade outer peripheral portion

17 trailing edge of blade

18 arc part

19 front part of blade

20 downstream face

21 first arc of a circle

22 projection

24 concave part

25 upstream face

26 second arc of a circle

27. 27a end portion

28. 28a groove part

32. 35, 35a swirl of the air flow

36 rectifying plate

51 cover

52 opening part

53 line component

54 gap

56 stripe-shaped wind speed distribution area

66 leaf root

67 blade end

68 downstream side peeling suppressing part

69 upstream side peel inhibiting portion

70. 70a face

71. 71a upstream end portion

72. 72a downstream end portion

73 connection point

80. 82 toward the downstream side in the direction of the rotation axis

90 blower device

102 rib

103 leading edge in the direction of rotation

104 region

105 sides

106 air flow

Claims

1. A blower device, comprising:

an impeller having a plurality of blades fixed on the outer periphery of the hub;

an electric motor that rotates the impeller; and

frame, which supports the motor,

in,

The air blower includes: an arc-shaped portion swelled upstream in the rotation axis direction of the blade from a blade front edge to a blade rear edge of the blade; and a blade front portion arranged along the blade front edge,

The blade front portion is provided with a downstream peeling suppressing portion on a surface downstream of the blade leading edge in the blade rotation axis direction, and is provided with an upstream peeling suppressing portion on a blade upstream surface in the blade rotation axis direction from the blade leading edge. department,

The downstream-side detachment suppressing portion includes: a protruding portion protruding in a first circular arc having a curvature greater than that of the arc-shaped portion; and a concave portion formed adjacent to the blade trailing edge side of the protruding portion,

The upstream side detachment suppressing portion includes an end portion formed with a second arc having a larger curvature than the arc portion, and a groove portion formed on the blade trailing edge side of the end portion.

2. The blower device according to claim 1, wherein:

When airflows with different angles with respect to the rotation axis flow into the blades,

The downstream-side detachment suppressing portion generates a vortex in the concave portion through the protruding portion and the concave portion when the blade rotates, and suppresses the flow of air at an angle close to the direction of the rotation axis with respect to the blade. The airflow generated under the peeling off of the surface on the downstream side in the direction of the rotation axis of the blade,

The upstream-side detachment suppressing portion passes through the end portion and the groove to generate a vortex in the groove when the blade rotates, and suppresses the flow of air at an angle close to the direction of the rotation axis with respect to the blade. The airflow generated under the peeling off of the surface on the upstream side in the direction of the rotation axis of the blade.

3. The blower device according to claim 1 or 2, wherein:

A cover having an opening through which air is sucked in from the outside and a plurality of wire members for dividing the opening is arranged on the upstream side of the impeller so as to be close to the impeller.

4. The blower device according to claim 1 or 2, wherein:

The blades include:

an inner peripheral portion of the blade where the tangent of the leading edge of the blade is oriented in a plan view with a radial component greater than a component in the direction of rotation; and

the outer peripheral portion of the blade in which the rotational direction component of the direction of the tangent of the leading edge of the blade in plan view is larger than the radial component,

The upstream peeling suppressing portion and the downstream peeling suppressing portion are provided only on the blade inner peripheral portion.

5. The blower device according to claim 1 or 2, wherein:

The end portion stands on the upstream side in the rotation axis direction of the impeller relative to the surface of the blade.

6. The blower device according to claim 1 or 2, wherein:

A plurality of rectifying plates are provided at the front portion of the blade so as to partition the groove portion, and the rectifying plates are formed in a semicircular plate shape having the same curvature as the second arc.