Fan Unit

Abstract

To provide a fan device capable of suppressing generation of noise while securing air capacity.SOLUTION: A fan device 10 includes a fan 20 having a plurality of blades 200. Each blade 200 is formed in such a manner that, out of an edge 210 of the blade 200, in a first region which is closest to the inner peripheral side and a third region which is closest to the outer peripheral side respectively, according as it goes from the inner peripheral side to the outer peripheral side along the edge 210, a skew angle at each position on the edge 210 gradually changes to the opposite side from the rotation direction, and out of the edge 210, in a second region existing between the first region and the third region, according as it goes from the inner peripheral side to the outer peripheral side along the edge 210, the skew angle at each position on the edge 210 gradually changes to the rotation direction side.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a fan device for pumping air. [Background technology]

[0002] For example, a vehicle is provided with a fan device for blowing air through a heat exchanger such as a radiator. As disclosed in Patent Document 1 below, the fan device includes a fan having a plurality of blades and a motor for rotating the fan.

[0003] A variety of blade shapes have been proposed so far. Blades can be broadly classified as either swept-back or forward-swept. A "swept-back blade" is a blade that has a shape in which the blade extends at an angle opposite to the direction of rotation as it moves from the inner periphery to the outer periphery. Patent Document 1 listed below describes an example of a fan device that has such swept-back blades.

[0004] A "forward-swept blade" is a blade that has a shape in which the blade extends at an angle in the direction of rotation from the inner periphery to the outer periphery. Patent Document 2 listed below describes an example of a fan device having such forward-swept blades. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2016-180362 A [Patent Document 2] Patent No. 3978083 Summary of the Invention [Problem to be solved by the invention]

[0006] It is known that, while a sufficient volume of air can be delivered from the fan device when the blades are swept back, noise associated with the operation of the fan device generally tends to be generated more easily than when the blades are swept forward. It is also known that, while a noise associated with the operation of the fan device generally tends to be reduced more easily than when the blades are swept back, the volume of air delivered from the fan device tends to be smaller when the blades are swept forward.

[0007] An object of the present disclosure is to provide a fan device that can suppress noise generation while ensuring a sufficient air volume. [Means for solving the problem]

[0008] The fan device according to the present disclosure is a fan device (10) that blows out air, and includes a fan (20) having a plurality of blades (200) and a motor (30) that rotates the fan. When the fan is viewed along its central axis of rotation (AX), the blades are formed such that, when either the front or rear edge of the blade along the rotation direction of the fan is defined as a shape-specifying edge (210) and the inclination angle of a straight line connecting a point corresponding to each position on the shape-specifying edge and the central axis of rotation is defined as the skew angle for each position, in the first region on the innermost side of the shape-specifying edge and the third region on the outermost side, the skew angle at each position on the shape-specifying edge gradually changes to the opposite side to the rotation direction as one moves from the inner circumference side to the outer circumference side along the shape-specifying edge, and in the second region of the shape-specifying edge between the first region and the third region, the skew angle at each position on the shape-specifying edge gradually changes to the rotation direction as one moves from the inner circumference side to the outer circumference side along the shape-specifying edge.

[0009] The blades of the fan device configured as described above are shaped such that the skew angle gradually changes in the opposite direction to the rotational direction as it approaches the outer periphery in both the first region on the inner periphery and the third region on the outer periphery. The overall shape of the blades can be said to be swept-back blades. Therefore, the fan device can ensure a sufficient volume of air being blown out.

[0010] In the blades of the fan device, the second region between the first and third regions has a shape in which the skew angle gradually changes toward the rotation direction as it approaches the outer periphery. This second region can be said to have the characteristics of a conventional forward-swept blade. Therefore, in the vicinity of the second region, as with a conventional forward-swept blade, the air flow that is blown out toward the outer periphery along the blade surface is suppressed, while the air flow that is blown out along the central axis of the fan rotation increases. As a result, the turbulence of the air flow that causes noise is reduced, making it possible to suppress noise generation compared to the conventional technology. Effect of the Invention

[0011] According to the present disclosure, a fan device is provided that can suppress noise generation while ensuring air volume. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of a fan device according to this embodiment and a vehicle on which the fan device is mounted. [Diagram 2] FIG. 2 is a diagram showing the configuration of a fan included in the fan device. [Diagram 3] FIG. 3 is a diagram showing a shroud member provided in the fan device. [Figure 4] FIG. 4 is a diagram for explaining a specific shape of the blades provided on the fan. [Diagram 5] FIG. 5 is a diagram for explaining a specific shape of the blades provided on the fan. [Figure 6]FIG. 6 is a diagram showing airflow in the vicinity of a fan device according to a comparative example. [Figure 7] FIG. 7 is a diagram showing air flows in the vicinity of the fan device according to this embodiment. [Figure 8] FIG. 8 is a diagram showing the configuration of a fan according to a comparative example. [Figure 9] FIG. 9 is a diagram showing the relationship between the blade shape and the performance index. [Figure 10] FIG. 10 is a diagram showing the relationship between the blade shape and the noise index. [Figure 11] FIG. 11 is a diagram showing the width of the blade at each position. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, the present embodiment will be described with reference to the accompanying drawings. In order to facilitate understanding of the description, the same components in each drawing are denoted by the same reference numerals as much as possible, and duplicated description will be omitted.

[0014] A fan device 10 according to this embodiment is a device mounted on a vehicle MV as shown in FIG. 1, and is configured as a device for blowing air through a heat exchanger HT.

[0015] First, the configuration of the vehicle MV will be described. In addition to the fan device 10, the vehicle MV is equipped with an engine EG and a heat exchanger HT. The engine EG is an internal combustion engine for generating driving force for the vehicle MV. The fan device 10 and the heat exchanger HT are disposed in a position forward of the engine EG in the internal space of the vehicle MV.

[0016] The heat exchanger HT is a heat exchanger, i.e., a radiator, for cooling the coolant circulating between the engine EG and the heat exchanger HT by exchanging heat with air. The air used for heat exchange in the heat exchanger HT is air introduced into the inside of the vehicle MV from a front grill FG provided at the front side of the vehicle MV. In FIG. 1, the flow of air from the front grill FG toward the heat exchanger HT is indicated by arrows.

[0017] The heat exchanger HT may be a heat exchanger different from the above. For example, the heat exchanger HT may be a condenser that is a part of an air conditioner for a vehicle. The heat exchanger HT may also be a combination of a plurality of heat exchangers.

[0018] The fan device 10 according to this embodiment is disposed downstream of the heat exchanger HT along the air flow direction and upstream of the engine EG. The fan device 10 sends out air from the front side to the rear side of the vehicle MV, thereby creating an air flow that passes through the heat exchanger HT.

[0019] The configuration of the fan device 10 will be described with reference to Figures 1 to 3. The fan device 10 includes a fan 20, a motor 30, and a shroud member 40.

[0020] The fan 20 is a member that creates an air flow by rotating. FIG. 2 shows the fan 20 as viewed from the downstream side (i.e., the rear side of the vehicle MV) along the direction in which the air is blown out. The rotation direction of the fan 20 is counterclockwise as indicated by the arrow AR1 in FIG. 2. As shown in FIG. 2, the fan 20 has a hub 21, blades 200, and a ring portion 22.

[0021] The hub 21 is a member formed in a generally cylindrical shape. The hub 21 is disposed with its central axis aligned along the front-rear direction of the vehicle MV. The central axis serves as the rotational center axis AX of the fan 20.

[0022] The blades 200 are parts that function as wings for blowing out air. A plurality of blades 200 are provided on the fan 20. The base of each blade 200 is connected to the side surface of the hub 21, and the blades 200 are arranged at equal or unequal intervals along the rotation direction of the fan 20. Each blade 200 extends from the side surface of the hub 21 toward the outer periphery. The blades 200 have the same shape. The specific shapes of the blades 200 will be described later.

[0023] The ring portion 22 is an annular member provided to connect the tips (i.e., the ends on the outer circumferential side) of the blades 200. Each blade 200 is formed to extend from the hub 21 to the ring portion 22. By providing such a ring portion 22, the rigidity of the entire fan 20 is increased.

[0024] The motor 30 is a rotating electric machine for rotating the fan 20 about a central rotation axis AX. As shown in Fig. 1, the motor 30 is connected to the fan 20 from the front side of the vehicle MV, and is supported by a stay 43 described below.

[0025] The shroud member 40 is a member provided to guide the flow of air between the heat exchanger HT and the fan 20, and to support the motor 30. Fig. 3 shows the shroud member 40 as viewed from the front side of the vehicle MV along the direction in which the air is blown out. The shroud member 40 has an air guide plate 41 and a stay 43.

[0026] The air guide plate 41 is a plate-like member provided so as to cover the fan 20. The air guide plate 41 is formed so that its external shape when viewed along the direction in which the air is blown out is generally rectangular. The fan device 10 is mounted on the vehicle MV with the long sides of the air guide plate 41 aligned along the left-right direction of the vehicle MV and the short sides of the air guide plate 41 aligned along the up-down direction.

[0027] A circular opening 42 for passing air is formed in the air guide plate 41. When viewed along the direction in which the air is blown out, the opening 42 is formed at a position overlapping with the fan 20. At this time, the center of the opening 42 coincides with the rotational center axis AX of the fan 20. The diameter of the opening 42 is approximately the same as the diameter of the ring portion 22 of the fan 20, but the respective diameters may be configured to be different from each other.

[0028] When viewed along the direction in which the air is blown out, the outer shape of the air guide plate 41 generally coincides with the outer shape of the heat exchanger HT located in front. A protruding wall 45 is formed on the air guide plate 41. The protruding wall 45 is an annular wall provided so as to protrude from the outer peripheral end of the air guide plate 41 toward the heat exchanger HT located in front. The fan device 10 is installed with the tip of the protruding wall 45 in contact with the heat exchanger HT over the entire circumference. Therefore, the space between the air guide plate 41 and the heat exchanger HT is separated from the outside by the protruding wall 45.

[0029] The stays 43 are rod-shaped members formed to extend from the edge of the opening 42 toward the motor holding portion 44 located inside. A plurality of stays 43 are provided, and are arranged in a line along the edge of the opening 42. The motor holding portion 44 is a portion for housing and holding the motor 30 inside. The motor holding portion 44 is a roughly cylindrical container, and the portion on the back side of the page in FIG. 3 is open. The motor 30 is inserted into the motor holding portion 44 from this open portion and is held therein. The ends of each stay 43 are connected to the side of the motor holding portion 44.

[0030] In this manner, motor 30 is supported by each stay 43 while being held inside motor holding portion 44. As shown in Fig. 1, stay 43 is disposed at a position upstream of fan 20 along the direction in which air is blown out.

[0031] The specific shape of the blades 200 included in the fan 20 will be described with reference to Fig. 4. Fig. 4 is an enlarged view of a portion of the fan 20 shown in Fig. 3.

[0032] 4, when fan 20 is viewed along the central axis of rotation AX, an edge of blade 200 that is on the rear side in the rotation direction of fan 20 (i.e., an edge on the opposite side to the rotation direction) is hereinafter also referred to as "edge 210." Also, an edge of blade 200 that is on the front side in the rotation direction of fan 20 (i.e., an edge on the rotation direction side) is hereinafter also referred to as "edge 220."

[0033] In the following, the shape of the edge 210 of the pair of edges 210, 220 of the blade 200 will be described in detail, thereby specifying the specific shape of the blade 200. The edge 210 corresponds to the "shape-specifying edge" in this embodiment.

[0034] Point P0 shown in Fig. 4 is the point indicating the innermost position (i.e., the end portion on the rotation axis AX side) of edge 210, which is the shape-specific edge. Point P10 shown in the same figure is the point indicating the outermost position of edge 210, which is the shape-specific edge. Edge 210 extends in a curved shape in the range from points P0 to P10.

[0035] For ease of explanation, the straight line connecting the rotation axis AX and point P0 in Fig. 4 is also referred to as the "reference line L0" below. Also, for each position on edge 210, which is the shape-specific edge, the inclination angle of the straight line connecting the point corresponding to that position and the rotation axis AX with respect to the reference line L0 is defined as the "skew angle" for that position. The reference line L0 can also be said to be the line with a skew angle of 0 degrees.

[0036] For example, in Fig. 4, a straight line connecting point P1 on edge 210 and rotation axis AX is shown as line L1. θ1, which is the inclination angle of line L1 with respect to reference line L0, is the skew angle for the position of point P1. Similarly, in Fig. 4, a straight line connecting point P2 on edge 210 and rotation axis AX is shown as line L2. θ2, which is the inclination angle of line L2 with respect to reference line L0, is the skew angle for the position of point P2.

[0037] In this embodiment, the skew angle is defined as the inclination angle of a line L1, etc., with respect to a reference line L0. However, the reference for the skew angle may be a line other than the reference line L0. For example, the skew angle may be defined as the inclination angle of a line connecting a point corresponding to a position on the edge 210 and the rotation center axis AX with respect to a horizontal plane. Regardless of the line with which the skew angle is defined as the reference, the shape of the edge 210 described below will be expressed in the same way.

[0038] The skew angle can be obtained for each position on edge 210, which is a shape-specific edge, not limited to the positions of points P1 and P2 shown in FIG. 4. FIG. 5 is a graph showing the distribution of skew angles at each position. "x" shown on the horizontal axis of the graph is a coordinate indicating each position on edge 210. Specifically, the distance (linear distance along the radial direction) from the side surface of hub 21 to each position on edge 210 is expressed as the coordinate x of each position. The position of x=0 in FIG. 5 corresponds to point P0 in FIG. 4. The position of x=x3 in FIG. 5 corresponds to point P10 in FIG. 4.

[0039] On the vertical axis in Fig. 5, the direction in which the skew angle corresponding to each position on the edge 210 is inclined toward the opposite side to the rotation direction with respect to the reference line L0 is taken as positive. When the direction of the skew angle is defined in this way, for example, θ1 and θ2 in Fig. 4 are both positive values.

[0040] 5, in the x-coordinate range of edge 210, which is a shape-specific edge, from 0 to x1, the skew angle at each position on edge 210 gradually changes to the opposite side to the rotation direction as one moves from the inner circumference side to the outer circumference side along edge 210. This range is the innermost region of edge 210, and corresponds to the "first region" in this embodiment.

[0041] Similarly, in the range of x coordinates from x2 to x3 of edge 210, which is the shape-specific edge, the skew angle at each position on edge 210 gradually changes to the opposite side to the rotation direction as one moves from the inner circumference side to the outer circumference side along edge 210. This range is the outermost region of edge 210, and corresponds to the "third region" in this embodiment.

[0042] In the x-coordinate range of edge 210, which is the shape-specific edge, from x1 to x2, the skew angle at each position on edge 210 gradually changes toward the rotation direction as one moves from the inner circumference side to the outer circumference side along edge 210. This range is a region of edge 210 between the first region and the third region, and corresponds to the "second region" in this embodiment.

[0043] Thus, in the first region on the innermost side and the third region on the outermost side of edge 210, which is the shape-specific edge, each blade 200 is formed so that the skew angle at each position on edge 210 gradually changes to the opposite side to the rotation direction as one moves from the inner periphery side to the outer periphery side along edge 210. Also, in the second region of edge 210, which is between the first region and the third region, each blade 200 is formed so that the skew angle at each position on edge 210 gradually changes to the rotation direction as one moves from the inner periphery side to the outer periphery side along edge 210.

[0044] The shape of the blade 200 can be expressed as a shape that has characteristics of a swept-back wing in the first and third regions, and a shape that has characteristics of a forward-swept wing in the second region between them. In the example of Fig. 5, the skew angle is a negative value in the vicinity of the portion where the x-coordinate is x2. In other words, a part of the edge 210, which is the shape-specifying edge, extends beyond the reference line L0 in Fig. 4 and into the direction of rotation. Instead of this embodiment, the entire edge 210, which is the shape-specifying edge, may be shaped to be contained on the opposite side of the reference line L0 to the direction of rotation.

[0045] The advantage of forming the blade 200 in such a shape will be described. FIG. 6 shows a schematic representation of the air flow during operation of the fan device 10A according to the comparative example. This comparative example differs from the present embodiment only in the shape of the blade 200A provided on the fan 20A. FIG. 8 shows the shape of the fan 20A from the same perspective as FIG. 2. As shown in FIG. 8, the edge 210A of the blade 200A on the rear side along the rotation direction and the edge 220A on the front side along the rotation direction both extend at an incline toward the opposite side to the rotation direction as they move from the inner periphery to the outer periphery. That is, in this comparative example, each blade 200A is formed as a swept-back blade similar to the conventional blade. In other words, the blade 200A of this comparative example does not have a portion corresponding to the second region in this embodiment.

[0046] Planes S1 and S2 shown in Fig. 6 are both imaginary planes for illustrating the air flow in the vicinity of the fan device 10A. Planes S1 and S2 are both planes that include the rotation axis AX, and intersect perpendicularly with each other at the rotation axis AX. Arrows AR21 and AR22 in Fig. 6 diagrammatically represent the air flow on planes S1 and S2.

[0047] The arrow AR10 in Fig. 6 represents the flow of air sent out from the rotating blade 200A in the direction along the central axis of rotation AX. This flow is also referred to as the "main flow" below. As is well known, when the blade 200A is formed as a swept-back blade, the flow rate of the main flow as indicated by the arrow AR10 becomes large, so that a sufficient amount of air can be sent out from the fan unit 10A.

[0048] The arrows AR11 in Fig. 6 represent the flow of air that is sent out along the surface of the blade 200A toward the outer periphery. This flow is also referred to as a "diagonal flow" below. If the blade 200A is configured as a swept-back wing, the flow rate of the diagonal flow as indicated by the arrows AR11 also increases.

[0049] In the vicinity of the rotating blade 200A, a reverse airflow occurs along the rotation axis AX toward the hub 21, as indicated by the arrow AR21. Under such circumstances, if the above-mentioned diagonal flow as indicated by the arrow AR11 occurs, vortexes as indicated by the arrow AR22 may be generated, or air may stagnate in some areas, which may easily cause turbulence in the airflow. As a result, the blade 200A formed as a swept-back blade tends to generate relatively loud noise during the operation of the fan unit 10A.

[0050] When the blade 200A is formed as a conventional swept-back blade as in this comparative example, a sufficient amount of air can be ensured, but the problem of increased noise is likely to occur. Therefore, in the fan device 10 according to this embodiment, in order to reduce such noise, the blade 200 is shaped to have the first region, second region, and third region described above.

[0051] FIG. 7 is a schematic diagram of the air flow during operation of the fan device 10 according to this embodiment, in a manner similar to that of FIG.

[0052] As described above, the shape of the blade 200 of the fan device 10 has the characteristics of a swept-back blade in both the first region on the inner periphery side and the third region on the outer periphery side. Therefore, the blade 200 as a whole can be said to be a swept-back blade. Therefore, while the fan device 10 is in operation, as shown by the arrow AR10 in FIG. 7, the main flow becomes large to the same extent as in the comparative example. Therefore, in this embodiment as well, it is possible to ensure a sufficient amount of airflow sent out from the fan device 10.

[0053] The portion enclosed by dotted line DL1 in Fig. 7 corresponds to the second region of blade 200. As described above, the shape of this portion has the characteristics of a forward-swept wing. Therefore, in this portion, the diagonal flow as indicated by arrow AR11 in Fig. 6 is unlikely to occur, and the main flow as indicated by arrow AR12 in Fig. 7 is likely to occur.

[0054] In the example of FIG. 7, as shown by the arrow AR31, a reverse flow of air occurs along the rotation axis AX toward the hub 21. However, in this embodiment, the diagonal flow is suppressed by providing the second region, so that vortexes and air stagnation caused by the diagonal flow are unlikely to occur. The air flowing reversely as shown by the arrow AR31 merges with the main flow as shown by the arrow AR12 and smoothly changes its flow direction as shown by the arrow AR32. As a result, in the fan device 10 according to this embodiment, it is possible to suppress the generation of noise while ensuring the amount of airflow as in the case of conventional forward-swept blades.

[0055] Incidentally, as described with reference to Fig. 6, vortexes and air stagnation caused by diagonal flow are particularly likely to occur in a configuration in which the stay 43 is disposed upstream of the fan 20, as in this embodiment. Therefore, the effect of adopting the shape of the blade 200 as in this embodiment is particularly large in a fan device 10 configured such that the stay 43 is disposed upstream of the fan 20 along the direction in which the air is blown out. However, it goes without saying that the shape of the blade 200 as in this embodiment can also be adopted in a fan device configured such that the stay 43 is disposed downstream of the fan 20 along the direction in which the air is blown out.

[0056] In this embodiment, of the pair of edges 210, 220 that the blade 200 has, the rear edge 210 along the direction of rotation is a shape-specific edge, and the shape of the shape-specific edge has a first region, a second region, and a third region.

[0057] The shape of the edge 220 of the blade 200 on the opposite side to the shape-specific edge along the rotation direction is generally similar to the edge 210, as shown in FIG. 4 and other figures. However, a serration 221 consisting of multiple projections and recesses is formed in a portion of the edge 220 near the end on the outer periphery side. This further suppresses noise during rotation of the fan 20. If the serration 221 is not formed on the edge 220, the shape of the edge 220 will also have a first region, a second region, and a third region, like the edge 210. In this way, the blade 200 may be shaped so that both the edge 210 and the edge 220 are shape-specific edges.

[0058] The serrations may be formed on the edge 210 instead of the edge 220. In this case, the edge 220 is a shape-specific edge having a first region, a second region, and a third region. In this manner, the shape-specific edge may be at least one of the edge 210 on the rear side along the rotation direction and the edge 220 on the front side.

[0059] A more specific shape of the blade 200 will be described. For ease of explanation, in the following, for each position on the shape-specifying edge when viewed along the rotation axis AX, the value obtained by dividing the radial distance from the end of the shape-specifying edge on the rotation axis AX side to the position by the radial distance from one end of the shape-specifying edge to the other end is defined as the "span value" for the position.

[0060] The "end of the shape-specific edge on the rotation axis AX side" in the above means point P0 in the example of Fig. 4. The "radial distance from one end to the other end of the shape-specific edge" means the radial distance from point P0 to point P10 in the example of Fig. 4. In other words, it is the distance obtained by subtracting the distance from the rotation axis AX to point P0 from the distance from the rotation axis AX to point P10.

[0061] The above span values ​​can also be considered as coordinates that represent the radial distance from the side surface of hub 21 to each position on edge 210, non-dimensionally expressed as a value ranging from 0 to 1. In the example of FIG. 4, the span value of point P0 is 0, and the span value of point P10 is 1.

[0062] The inventors verified the performance of blades 200 of various shapes while individually changing the span value at the boundary between the first and second regions (x1 in FIG. 5), the span value at the boundary between the second and third regions (x2 in FIG. 5), and the skew angle at each position. As a result, they found that in order to suppress the noise of fan device 10 more than before and to ensure a larger air volume of fan device 10 than before, it is desirable to keep each parameter within the following range. Note that the numerical value of the "skew angle" in the following description is a numerical value when the skew angle is an angle with respect to the reference line L0 in FIG. 4.

[0063] (1) Span value at the boundary between the first and second regions (x1 in Figure 5): in the range of 0.1 to 0.4. (2) Span value at the boundary between the second and third regions (x2 in Figure 5): in the range of 0.4 to 0.6. (3) Skew angle at the boundary between the first and second regions (x1 in FIG. 5): within the range of 4 degrees to 12 degrees. (4) Skew angle at the boundary between the second and third regions (x2 in FIG. 5): in the range of 2 to 7 degrees. (5) The skew angle of the shape-specific edge at the end position farther from the rotation center axis AX (x3 in FIG. 5): within the range of 16 degrees to 20 degrees.

[0064] In the following, the "position which is the boundary between the first and second regions (x1 in Figure 5)" will also be referred to as "position X1", the "position which is the boundary between the second and third regions (x2 in Figure 5)" will also be referred to as "position X2", and the "position which is the end of the shape-specific edge farther from the rotation center axis AX (x3 in Figure 5)" will also be referred to as "position X3".

[0065] 9 shows the relationship between the span value (horizontal axis) at position X2 and the performance index (vertical axis) of the fan device 10. The "performance index" is an index that indicates the amount of air sent out from the fan device 10, and the larger the air volume, the larger the performance index.

[0066] Line L1 in Fig. 9 shows the performance index when the skew angle at position X1 is 4 degrees. Line L2 in Fig. 9 shows the performance index when the skew angle at position X1 is 12 degrees. As shown in Fig. 9, the performance index of fan device 10 increases as the skew angle at position X1 increases.

[0067] "Th1" in Fig. 9 represents the performance index of a conventional product such as the comparative example in Fig. 8. It can be seen that even when the skew angle at position X1 is 4 degrees (line L1), if the span value at position X2 is in the range of 0.4 to 0.6, the performance index is improved compared to the conventional product. For this reason, as shown in (2) above, it is preferable that the span value at position X2 is in the range of 0.4 to 0.6, and it is also preferable that the skew angle at position X1 is 4 degrees or more, as shown in (3) above.

[0068] 10 shows the relationship between the skew angle (horizontal axis) at position X1 and the noise index (vertical axis) of the fan device 10. The "noise index" is an index that indicates the noise reduction performance of the fan device 10, and the quieter the sound made by the fan device 10 during operation, the higher the noise index.

[0069] Line L3 in Fig. 10 shows the noise index when the span value at position X1 is 0.4. Line L4 in Fig. 10 shows the noise index when the span value at position X1 is 0.1. As shown in Fig. 10, the smaller the span value at position X1, the larger the noise index of the fan device 10.

[0070] "Th2" in Fig. 10 represents the noise index for a conventional product such as the comparative example in Fig. 8. It can be seen that even when the span value at position X1 is 0.4 (line L3), if the skew angle at position X1 is in the range of 12 degrees or less, the noise index is improved compared to the conventional product. For this reason, as shown in (1) above, it is preferable that the span value at position X1 is 0.4 or less, and as shown in (3) above, it is preferable that the skew angle at position X1 is 12 degrees or less.

[0071] In the above, the basis for only some of the values ​​of the parameter ranges shown in (1) to (5) above has been explained. Note that the above parameters are intricately intertwined, and the values ​​of some parameters affect the appropriate ranges of other parameters. For example, in the example of Figure 9, if the skew angle at position X1 is smaller than 4 degrees, the graph showing the performance index will be below line L1, so the appropriate range of the span value at position X2 will be narrower than the range shown in (2) above.

[0072] If we were to show all the reasons for each parameter shown in (1) to (5) above, it would be necessary to list all the data for all the possible shape combinations performed by the inventors, which is not realistic, so we will not present data for parameters other than those described above. In any case, the inventors have confirmed that as long as the values ​​of each parameter are within the numerical ranges shown in (1) to (5) above, both the performance index and the noise index will be higher than before, regardless of how the values ​​of each parameter are selected.

[0073] When one of the span value at position X1 and the span value at position X2 is set to 0.4, it is preferable to secure a second region by setting the other to a value different from 0.4.

[0074] 11 shows the relationship between each position (horizontal axis) of edge 210, which is a shape-specifying edge, and the width (vertical axis) of blade 200 along the circumferential direction at that position. However, what is shown in FIG. 11 is the shape of blade 200 when serrations 221 are not formed on edge 210.

[0075] 11, as the span value at the above-mentioned position increases, the circumferential width of the blade 200 also increases. In other words, the circumferential width of the blade 200 increases toward the outer periphery. With this configuration, the performance index of the fan device 10 can be further improved.

[0076] In a configuration in which serrations 221 are formed on blade 200 as in this embodiment, the width of blade 200 along the circumferential direction may be configured to become larger toward the outer periphery in the range excluding the portion in which serrations 221 are formed (the range on the inner side of serrations 221).

[0077] The present embodiment has been described above with reference to specific examples. However, the present disclosure is not limited to these specific examples. Any design modifications made by a person skilled in the art to these specific examples are also included within the scope of the present disclosure as long as they have the features of the present disclosure. The elements of each of the above-mentioned specific examples and their arrangements, conditions, shapes, etc. are not limited to those exemplified and can be changed as appropriate. The combination of each of the elements of each of the above-mentioned specific examples can be changed as appropriate as long as no technical contradiction occurs. [Explanation of symbols]

[0078] 10: Fan unit 20: Fan 200: Blade 210, 220: Edge 30:Motor AX: Rotation axis

Claims

1. A fan device (10) for blowing air, comprising: A fan (20) having a plurality of blades (200); A motor (30) for rotating the fan; A plurality of stays (43) for supporting the motor; the stay is disposed at a position upstream of the fan along a direction in which air is blown out, When the fan is viewed along its central axis of rotation (AX), The blade has an edge on either the front side or the rear side along the rotation direction of the fan as a shape-specific edge (210); For each position on the shape specifying edge, when the inclination angle of a straight line connecting a point corresponding to the position and the rotation central axis is defined as the skew angle for the position, In each of the first region located on the innermost side and the third region located on the outermost side of the shape-specifying edge, the skew angle at each position on the shape-specifying edge gradually changes to the opposite side to the rotation direction as going from the inner periphery side to the outer periphery side along the shape-specifying edge, In a second region of the shape-specifying edge between the first region and the third region, each of the blades is formed such that the skew angle at each position on the shape-specifying edge gradually changes toward the rotation direction as the skew angle moves from the inner periphery side to the outer periphery side along the shape-specifying edge, When the value obtained by dividing the radial distance from the end of the shape-specifying edge on the side of the rotation center axis to the position on each position on the shape-specifying edge by the radial distance from one end to the other end of the shape-specifying edge is defined as the span value for the position, The span value at the boundary between the first region and the second region is within a range of 0.1 to 0.4, and A fan device, wherein the span value at the boundary between the second region and the third region is within a range of 0.4 to 0.

6.

2. A fan device (10) for blowing out air, A fan (20) having a plurality of blades (200); A motor (30) for rotating the fan; A plurality of stays (43) for supporting the motor; the stay is disposed at a position upstream of the fan along a direction in which air is blown out, When the fan is viewed along its central axis of rotation (AX), The blade has an edge on either the front side or the rear side along the rotation direction of the fan as a shape-specific edge (210); For each position on the shape specifying edge, when the inclination angle of a straight line connecting a point corresponding to the position and the rotation central axis is defined as the skew angle for the position, In each of the first region located on the innermost side and the third region located on the outermost side of the shape-specifying edge, the skew angle at each position on the shape-specifying edge gradually changes to the opposite side to the rotation direction as going from the inner periphery side to the outer periphery side along the shape-specifying edge, In a second region of the shape-specifying edge between the first region and the third region, each of the blades is formed such that the skew angle at each position on the shape-specifying edge gradually changes toward the rotation direction as the skew angle moves from the inner periphery side to the outer periphery side along the shape-specifying edge, When viewed along the central axis of rotation, When a straight line connecting the rotation axis and an end of the shape specifying edge on the rotation axis side is defined as a reference line where the skew angle is 0 degrees, The skew angle at the boundary between the first region and the second region is within a range of 4 degrees to 12 degrees, and A fan device, wherein the skew angle at a boundary between the second region and the third region is within a range of 2 degrees to 7 degrees.

3. 3. The fan device according to claim 2, wherein the skew angle at a position of the shape-specifying edge that is an end portion farther from the central axis of rotation is within a range of 16 degrees to 20 degrees.

4. The fan apparatus according to claim 1 , further comprising a ring portion (22) formed to connect tips of the respective blades.

5. The fan device according to any one of claims 1 to 4, wherein a serration (221) consisting of a plurality of projections and recesses is formed on an edge (220) of the blade that is on the opposite side to the shape-specific edge along the direction of rotation.

6. The fan apparatus according to claim 1 , wherein a circumferential width of the blade increases toward an outer periphery.

7. The fan device according to claim 5 , wherein a width of the blade in a circumferential direction in a portion where the serrations are not formed increases toward an outer periphery of the blade.

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