Electric fan

Abstract

To provide an electric fan capable of facilitating removal of a cover.SOLUTION: An electric fan having a pair of impellers 25, 26 includes a cover attachment member 30 having an annular portion 32a and provided between the pair of impellers 25, 26, a rear side cover 21 attached to the cover attachment member 30 by a first attachment screw S1 in a state of being positioned on the annular portion 32a and covering one of the pair of impellers 25, 26, and a front side cover 22 attached to the cover attachment member 30 by a second attachment screw S2 in a state of being positioned on the annular portion 32a and covering the other of the pair of impellers 25, 26. The first attachment screw S1 and the second attachment screw S2 are attached to the cover attachment member 30 in a mutually independent state, and at least one of them is exposed to the outside of the electric fan.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a fan.

Background Art

[0002] Conventionally, a fan having a pair of impellers has been known. For example, Patent Document 1 discloses a double-reverse type fan having a first impeller on the upstream side and a second impeller on the downstream side. In this double-reverse type fan, the first impeller is rotationally driven by a motor, and the second impeller is provided rotatably with respect to the rotation axis. When the first impeller rotates, the second impeller rotates in a direction opposite to the rotation direction of the first impeller by the wind force of the first impeller.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, the double-reverse type fan disclosed in Patent Document 1 has an upstream grill which is a cover covering the first impeller and a downstream grill which is a cover covering the second impeller. In this type of fan, for the first impeller and the grill covering it, and the second impeller and the grill covering it, in order to facilitate the cleaning of attached dust and the like, it is required that the grill covering the first impeller and the grill covering the second impeller can be easily removed independently.

[0005] The present invention has been created in view of the above problems, and an object thereof is to provide a fan in which the cover can be easily removed.

Means for Solving the Problems

[0006] The fan of the present invention is a fan having a pair of impellers, which has an annular annular portion, a cover mounting member provided between the pair of impellers, and a first screw attached to the cover mounting member in a state of being positioned on the annular portion, and covering one of the pair of impellers. A first cover, and a second cover attached to the cover mounting member by a second screw in a state of being positioned on the annular portion and covering the other of the pair of impellers, wherein the first screw and the second screw are independently attached to the cover mounting member, and at least one of them is exposed to the outside of the fan.

Advantages of the Invention

[0007] According to the present invention, it is possible to provide a fan in which the cover can be easily removed.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0009] Embodiments of the present invention will be described with reference to the drawings. As shown in FIGS. 1 and 2, the electric fan 1 according to this embodiment is a small-sized tabletop electric fan 1, which is of a double-reverse type, and includes a main body 10 and a blowing head 20 provided above the main body 10. On the front side of the main body 10, there is provided a control knob 12 for the user to control the on / off of the power of the electric fan 1, the blowing speed of the blowing head 20, the presence or absence of the head swing in the left and right directions, etc. With the electric fan 1, the user can cause the blowing head 20 to blow air by operating the control knob 12. Hereinafter, the side of the main body 10 where the control knob 12 is provided (the downstream side of the blowing flow path) is defined as the front side of the electric fan 1, the opposite side is defined as the rear side, and the right side and the left side when the main body 10 is viewed from the front side are defined as the right side and the left side of the electric fan 1 for description.

[0010] The main body 10 has a substantially disk-shaped mounting portion 14 that is placed on a table or the like, and a substantially columnar rotating portion 16 that swings left and right by rotating around an axis along the vertical direction with respect to the mounting portion 14. Inside the main body 10, there are housed a control mechanism for controlling the operation of the electric fan 1 based on the operation of the control knob 12, a head swing motor (not shown) for swinging the rotating portion 16 left and right, a head swing mechanism (not shown) connected to the motor to realize the left and right head swing of the rotating portion 16, and the like. Further, on the upper surface of the rotating portion 16, there is provided an opening 16a that opens upward in a substantially rectangular shape. The lower end portion of the blowing head 20 is supported in the opening 16a so as to be swingable in the vertical direction with respect to the main body 10. The blowing head 20 rotates in the left and right directions together with the rotating portion 16.

[0011] As shown in FIGS. 3 and 4, the blower head 20 includes a rear cover (first cover) 21 provided on the rear side, i.e., the upstream side of the blower flow path, a front cover (second cover) 22 provided on the front side, i.e., the downstream side of the blower flow path, a cover attachment member 30 provided between the rear cover 21 and the front cover 22, a rear impeller 25 attached to the rear side of the cover attachment member 30, and a front impeller 26 attached to the front side of the cover attachment member 30. That is, the cover attachment member 30 is provided between the two impellers 25 and 26.

[0012] The rear cover 21 has a substantially short cylindrical shape with a slightly reduced diameter at the rear and a bottom, and is attached to the cover attachment member 30 so as to cover the rear impeller 25. The rear cover 21 has a grill shape in which substantially the whole of it is composed of beam-like parts, and includes a rear first grill part (side part) 21a that constitutes an annular side surface, and a rear second grill part 21b that is provided inside the rear first grill part 21a and constitutes a bottom surface. The rear first grill part 21a has a plurality of beam-like parts 21a1 extending linearly and parallel in the front-rear direction, and the rear second grill part 21b has a plurality of beam-like parts 21b1 extending linearly and parallel in the left-right direction.

[0013] At the lower end of the rear second grill part 21b, a concave opening part 21b2 that opens in a concave shape toward the front side is provided. In the concave opening part 21b2, a rear insertion hole 21H through which a first attachment screw (first screw) S1 for attaching the rear cover 21 to the cover attachment member 30 is inserted is provided so as to penetrate in the front-rear direction.

[0014] The front cover 22 has a substantially short cylindrical shape with a bottom on the front side, and is attached to the cover attachment member 30 so as to cover the front impeller 26. The front cover 22 has a side surface portion 22a that forms an annular side surface, and a grill-shaped front grill portion 22b that is provided inside the side surface portion 22a and forms the bottom surface. The front grill portion 22b has a plurality of beam-shaped portions 22b1 that linearly extend in parallel in the left-right direction. In a state where the fan 1 is placed on the placement surface, each beam-shaped portion 21b1 of the rear cover 21 and each beam-shaped portion 22b1 of the front cover 22 are parallel to the placement surface.

[0015] As shown in FIGS. 4 and 8(a), a minute front minute cylindrical portion 22a1 that extends in a substantially cylindrical shape in the front-rear direction is provided at the lower end portion on the inner surface side of the side surface portion 22a. Inside the front minute cylindrical portion 22a1, a front screw hole 22H that opens to the rear side and has a screw groove formed on the inner surface is provided. A second attachment screw (second screw) S2 for attaching the front cover 22 to the cover attachment member 30 is screwed into the front screw hole 22H.

[0016] The rear impeller 25 has a substantially cylindrical rear rotating portion 25a with a bottom on the rear side, and five rear blade portions 25b that extend outward from the outer peripheral surface of the rear rotating portion 25a. The front impeller 26 has a substantially cylindrical front rotating portion 26a with a bottom on the front side, and seven front blade portions 26b that extend outward from the outer peripheral surface of the front rotating portion 26a. Inside the rear rotating portion 25a, a rear drive mechanism (not shown) composed of a motor or the like for rotating the rear impeller 25 is accommodated. Inside the front rotating portion 26a, a front drive mechanism (not shown) composed of a motor or the like for rotating the front impeller 26 is accommodated. Since the fan 1 is a double-reverse type, the rear impeller 25 and the front impeller 26 are arranged with their rotation axis centers aligned in the axial flow direction, and their rotation directions are different from each other.

[0017] As shown in FIGS. 3 and 4 (see also FIGS. 8(b) and 9(a)), the cover attachment member 30 includes a rear attachment member (first attachment member) 31 provided on the rear side (rear cover 21 side) and connected to the swing mechanism in the main body 10, and a front attachment member (second attachment member) 32 provided on the front side (front cover 22 side) for positioning the covers 21 and 22. The front attachment member 32 includes an annular portion 32a that forms its outer periphery, a circular central portion 32b provided at the central portion inside the annular portion 32a, and a front head portion 32c provided below the annular portion 32a and forming the front side of the neck portion of the blower head 20. The rear cover 21 and the front cover 22 are respectively attached to the front and rear of the annular portion 32a.

[0018] The annular portion 32a is provided to be slightly smaller in diameter than the circular portion at the front end of the rear first grill portion 21a of the rear cover 21 and the circular portion at the rear end of the side surface portion 22a of the front cover 22. The central circular portion 32b has a shape that is concave in the front and rear directions and is provided with a plurality of through holes. A front drive mechanism is attached to the front side of the central circular portion 32b. The central circular portion 32b is supported by three beam-like portions extending inward from the annular portion 32a, and the beam-like portion extending in the vertical direction is the front wiring accommodation portion 32d. Further, a front notch portion 32c1 that is cut in a substantially arc shape toward the rear is provided at approximately the center in the left-right direction of the lower edge of the front head portion 32c (see FIG. 9(a)). The front head portion 32c and the front wiring accommodation portion 32d have a hollow interior and are open to the rear side.

[0019] As shown in FIGS. 3 and 9(a), a front insertion hole 32H1 through which a second mounting screw S2 is inserted is provided in a shape penetrating in the front-rear direction at the boundary between the front wiring housing portion 32d and the front head portion 32c. The front insertion hole 32H1 is provided at a position overlapping the front screw hole 22H in the front-rear direction when the annular portion 32a and the front cover 22 are assembled. Further, at the lower end portion on the inner surface side of the front head portion 32c, two minute head-side minute cylindrical portions 32c2 extending substantially in a columnar shape in the front-rear direction are provided side by side in the left-right direction (see FIG. 4). Inside each head-side minute cylindrical portion 32c2, a head-side screw hole 32H2 that opens to the rear side and has a screw groove formed on the inner surface is provided. A third mounting screw S3 for attaching the rear mounting member 31 to the front mounting member 32 is screwed into each head-side screw hole 32H2.

[0020] As shown in FIGS. 3 and 4, the rear mounting member 31 has a circular upper circular portion 31a provided at the upper part thereof, a rear wiring housing portion 31b extending downward from the upper circular portion 31a, and a rear head portion 31c provided below the rear wiring housing portion 31b and constituting the rear side of the head portion of the blower head 20. The upper circular portion 31a has a shape that is recessed in the front and rear, and a plurality of through holes are provided. A rear drive mechanism is attached to the rear side of the upper circular portion 31a. Further, at a substantially central portion in the left-right direction of the lower end edge portion of the rear head portion 31c, a rear notch portion 31c1 that is cut out in a substantially arc shape toward the rear side is provided (see FIG. 3). The rear wiring housing portion 31b and the rear head portion 31c have a hollow interior and are open to the front side.

[0021] The enlarged view P of FIG. 4 is an enlarged perspective view of the rear head portion 31c viewed from the rear side. As shown in the enlarged view P of FIG. 4, a rear screw hole 31H1 that opens to the rear side and has a screw groove formed on the inner surface is provided in the upper portion of the rear head portion 31c. The rear screw hole 31H1 is provided at a position overlapping the rear insertion hole 21H in the front-rear direction when the rear mounting member 31 and the rear cover 21 are assembled. A first mounting screw S1 is screwed into the rear screw hole 31H1. That is, the first mounting screw S1 and the second mounting screw S2 are attached to the cover mounting member 30 independently of each other.

[0022] Also, in the lower part of the rear-side head portion 31c, two head-side insertion holes 31H2 through which the third mounting screws S3 are inserted are provided side by side in the left-right direction in a manner penetrating in the front-rear direction. Each head-side insertion hole 31H2 is provided at a position overlapping each head-side screw hole 32H2 in the front-rear direction when the rear-side mounting member 31 and the front-side mounting member 32 are assembled.

[0023] Next, the assembly mode (mounting method) of each member constituting the blower head 20 will be described. First, the rear impeller 25 in which the rear drive mechanism is housed in the rear rotation part 25a is attached to the upper circular part 31a of the rear-side mounting member 31, and the front impeller 26 in which the front drive mechanism is housed in the front rotation part 26a is attached to the central circular part 32b of the front-side mounting member 32.

[0024] Next, the rear-side mounting member 31 and the front-side mounting member 32 are assembled. At this time, the upper circular part 31a and the central circular part 32b, the rear-side wiring accommodation part 31b and the front-side wiring accommodation part 32d, the rear-side head portion 31c and the front-side head portion 32c, are assembled so as to overlap each other. Thereby, a space opened downward is formed between the front-side mounting member 32 and the rear-side mounting member 31. Wires from the rear drive mechanism and the front drive mechanism are accommodated in this space. Also, by assembling the rear-side mounting member 31 and the front-side mounting member 32, the rear-side notch part 31c1 and the front-side notch part 32c1 overlap in the front-rear direction, and a substantially circular opening is formed.

[0025] The wires accommodated in the space between the front-side mounting member 32 and the rear-side mounting member 31 are routed to the lower end sides of the mutually assembled front-side mounting member 32 and rear-side mounting member 31, and are drawn out from the opening formed between the rear-side notch part 31c1 and the front-side notch part 32c1 and connected to the control mechanism in the main body part 10. Next, in a state where the front-side mounting member 32 and the rear-side mounting member 31 are assembled, the third mounting screws S3 are respectively inserted through the head-side insertion holes 31H2 of the rear-side mounting member 31, and screwed into the head-side screw holes 32H2 of the front-side mounting member 32, whereby the two are connected.

[0026] Next, attach the front cover 22 in the correct orientation to the front side of the annular portion 32a. As a result, the front screw hole 22H of the front cover 22 overlaps with the front insertion hole 32H1 of the front attachment member 32 in the front-rear direction. Next, insert the second attachment screw S2 into the front insertion hole 32H1 from the rear side of the front attachment member 32 and screw it into the front screw hole 22H, thereby fixing the front cover 22 to the front side of the annular portion 32a. The configuration and attachment procedure for attaching the front cover 22 to the front side of the annular portion 32a in the correct orientation will be described in detail later.

[0027] Next, attach the rear cover 21 in the correct orientation to the rear side of the annular portion 32a. As a result, the upper portion of the rear neck portion 31c of the rear attachment member 31 is accommodated in the concave opening 21b2 of the rear cover 21, and the rear insertion hole 21H of the rear cover 21 overlaps with the rear screw hole 31H1 of the rear attachment member 31 in the front-rear direction. Next, insert the first attachment screw S1 into the rear insertion hole 21H from the rear side of the rear cover 21 and screw it into the rear screw hole 31H1, thereby fixing the rear cover 21 to the rear side of the annular portion 32a. The configuration and attachment procedure for attaching the rear cover 21 to the rear side of the annular portion 32a in the correct orientation will be described in detail later.

[0028] In this way, by attaching the rear cover 21 after attaching the front cover 22 to the annular portion 32a first, the second attachment screw S2 is covered by the rear cover 21. For this reason, only the first attachment screw S1 out of the first attachment screw S1 and the second attachment screw S2 is exposed to the outside of the fan. In the above manner, each member constituting the blower head 20 is assembled.

[0029] Next, a configuration for attaching the rear cover 21 and the front cover 22 to the annular portion 32a in the correct orientation will be described. As shown in FIGS. 3, 4, 5, 8(b), and 9(a), a plurality of engaging portions 32e that slightly rise in a wall shape toward the outer diameter side of the annular portion 32a are provided on the outer peripheral surface of the annular portion 32a. Each engaging portion 32e is provided at intervals in the circumferential direction of the annular portion 32a. Among each engaging portion 32e, four engaging portions 32e that rise in a wall shape from the rear side portion of the outer peripheral surface of the annular portion 32a are defined as the rear engaging portions 32e1. Also, among each engaging portion 32e, four engaging portions 32e that rise in a wall shape from the front side portion of the outer peripheral surface of the annular portion 32a are defined as the front engaging portions 32e2.

[0030] As shown in FIG. 5 and the like, on the outer peripheral surface of the annular portion 32a, there is no wall-shaped portion provided in front of each rear engaging portion 32e1, and it is open. For this reason, the rear engaged portions 21e of the rear cover 21, which will be described later, can be respectively brought into contact with and engaged with the front sides of each rear engaging portion 32e1. Similarly, on the outer peripheral surface of the annular portion 32a, there is no wall-shaped portion provided behind each front engaging portion 32e2, and it is open. For this reason, the front engaged portions 22e of the front cover 22, which will be described later, can be respectively brought into contact with and engaged with the rear sides of each front engaging portion 32e2.

[0031] Note that, as shown in FIGS. 5 and 9(a), in the rear side portion of the outer peripheral surface of the annular portion 32a, the position where no wall-shaped portion is provided and is shifted in one circumferential direction of the annular portion 32a from each rear engaging portion 32e1 is defined as the rear start position BS. Also, as shown in FIGS. 5 and 8(b), in the front side portion of the outer peripheral surface of the annular portion 32a, the position where no wall-shaped portion is provided and is shifted in the other circumferential direction of the annular portion 32a from each front engaging portion 32e2 is defined as the front start position FS.

[0032] Also, as shown in FIG. 5, at the upper end portion of the outer peripheral surface of the annular portion 32a, two first marks M1 that are recessed in a substantially U shape when viewed from above are provided so as to face each other in the front-rear direction. Among the two first marks M1, at a position shifted in one circumferential direction of the annular portion 32a from the first mark M1 provided on the rear side portion of the outer peripheral surface of the annular portion 32a, a second mark M2 that is recessed in a substantially U shape smaller than the first mark M1 when viewed from above is provided. Similarly, at a position shifted in the other circumferential direction of the annular portion 32a from the first mark M1 provided on the front side portion of the outer peripheral surface of the annular portion 32a, a second mark M2 that is recessed in a substantially U shape smaller than the first mark M1 when viewed from above is also provided.

[0033] As shown in FIGS. 3 and 9(b), in the circular portion at the front end of the rear first grill portion 21a in the rear cover 21, four rear engaged portions 21e that slightly project in a thin wall shape toward the radially inner side are provided at intervals in the circumferential direction. Each rear engaged portion 21e is provided at a position corresponding in the front-rear direction to the four rear engaging portions 32e1 provided on the annular portion 32a. Specifically, the spreading angles θ5 to θ8 of two adjacent rear engaging portions 32e1 with respect to the center portion 21C of the circular portion are, in order clockwise from the upper spreading angle θ5 in FIG. 9(b), for example, θ5 = 110°, θ6 = 70°, θ7 = 110°, θ8 = 70°. Also, at the upper end portion of the circular portion, a rear mark 21M that is recessed in a substantially semicircular shape when viewed from above is provided.

[0034] As shown in FIGS. 4 and 8(a), in the circular portion at the rear end of the side surface portion 22a in the front cover 22, four front engaged portions 22e that slightly project in a thin wall shape toward the radially inner side are provided at intervals in the circumferential direction. Each front engaged portion 22e is provided at a position corresponding in the front-rear direction to the four front engaging portions 32e2 provided on the annular portion 32a. Also, at the upper end portion of the circular portion, a front mark 22M that is recessed in a substantially semicircular shape when viewed from above is provided.

[0035] Each front engaged part 22e, specifically, the spreading angles θ1 to θ4 of the circular-shaped parts of two adjacent front engaging parts 32e2 with respect to the center part 22C are, in order clockwise from the upper spreading angle θ1 in FIG. 8(a), for example, θ1 = 75°, θ2 = 120°, θ3 = 60°, θ4 = 105°. For this reason, the four front engaged parts 22e are provided in a non-rotationally symmetric arrangement (in other words, a non-rotationally symmetric arrangement with respect to the circumferential direction of the annular part 32a) when the center part 22C is taken as the rotation center.

[0036] Next, a procedure for attaching the rear cover 21 to the annular part 32a in the correct orientation will be described. When attaching the rear cover 21 to the annular part 32a, first, position the rear cover 21 behind the annular part 32a so that each rear engaged part 21e of the rear cover 21 faces the respective rear start position BS of the annular part 32a in the front-rear direction. As a result, the rear mark 21M of the rear cover 21 faces the second mark M2 provided on the rear portion of the outer peripheral surface of the annular part 32a in the front-rear direction.

[0037] Next, assemble the rear cover 21 to the annular part 32a by fitting each rear engaged part 21e into the respective rear start position BS in the above-positioned state. Next, slightly rotate and shift the rear cover 21 to the other side in the circumferential direction (the counterclockwise side in FIG. 9(a)) so that the rear mark 21M faces the first mark M1 provided on the rear portion of the outer peripheral surface of the annular part 32a in the front-rear direction. As a result, as shown in FIG. 7, each rear engaged part 21e faces the respective rear engaging part 32e1 in front of the rear engaging part 32e1, and the two are brought into contact with each other in the front-rear direction (a direction orthogonal to the circumferential direction). As a result, each rear engaged part 21e is engaged with the respective rear engaging part 32e1. In this way, the rear cover 21 can be attached to the annular part 32a in the correct orientation.

[0038] When removing the rear cover 21 from the annular portion 32a, it can be done by the reverse procedure of the above. That is, the rear cover 21 is slightly rotated and shifted in one circumferential direction (the clockwise side in Fig. 9(a)) so that the rear mark 21M is in a state of facing the second mark M2 provided on the rear portion of the outer peripheral surface of the annular portion 32a in the front-rear direction. By removing each rear engaged portion 21e through each rear start position BS, the rear cover 21 can be easily removed from the annular portion 32a.

[0039] Next, a procedure for attaching the front cover 22 to the annular portion 32a in the correct orientation will be described. When attaching the front cover 22 to the annular portion 32a, similar to the case of the rear cover 21, first, the front cover 22 is positioned in front of the annular portion 32a so that each front engaged portion 22e of the rear cover 21 faces each front start position FS of the annular portion 32a in the front-rear direction. As a result, the front mark 22M of the front cover 22 is in a state of facing the second mark M2 provided on the front portion of the outer peripheral surface of the annular portion 32a in the front-rear direction.

[0040] Next, with the above positioning state, each front engaged portion 22e is fitted into each front start position FS to assemble the front cover 22 to the annular portion 32a. Next, the front cover 22 is slightly rotated and shifted in one circumferential direction (the clockwise side in Fig. 8(b)) so that the front mark 22M is in a state of facing the first mark M1 provided on the front portion of the outer peripheral surface of the annular portion 32a in the front-rear direction. As a result, as shown in Fig. 6, each front engaged portion 22e faces each front engaging portion 32e2 at the rear side of each front engaging portion 32e2, and the two are in contact with each other in the front-rear direction (the direction orthogonal to the circumferential direction). As a result, each front engaged portion 22e is engaged with each front engaging portion 32e2. In this way, the front cover 22 can be attached to the annular portion 32a in the correct orientation.

[0041] In addition, even when removing the front cover 22 from the annular portion 32a, it can be done by the reverse procedure of the above. That is, the front cover 22 is slightly rotated and shifted in the other circumferential direction (the counterclockwise side in FIG. 8(b)) so that the front mark 22M is in a state of facing the second mark M2 provided on the front portion of the outer peripheral surface of the annular portion 32a in the front-rear direction, and by removing each front engagement portion 22e through each front start position FS, the front cover 22 can be easily removed from the annular portion 32a.

[0042] As described above, the blower 1 according to the present embodiment is a blower 1 having a pair of impellers 25, 26, having an annular annular portion 32a, a cover attachment member 30 provided between the pair of impellers 25, 26, and a rear cover 21 that is attached to the cover attachment member 30 by a first attachment screw S1 in a state of being positioned on the annular portion 32a and covers one of the pair of impellers 25, 26, and a front cover 22 that is attached to the cover attachment member 30 by a second attachment screw S2 in a state of being positioned on the annular portion 32a and covers the other of the pair of impellers 25, 26. The first attachment screw S1 and the second attachment screw S2 are attached to the cover attachment member 30 independently of each other, and at least one of them is exposed to the outside of the blower 1.

[0043] According to the blower 1 of the present embodiment configured as described above, in the manufacturing process, by screwing the first attachment screw S1 and the second attachment screw S2 in a manner that can be removed by the user, among the first attachment screw S1 and the second attachment screw S2 that are attached to the cover attachment member 30 independently of each other, the user can use a tool to remove one of the screws exposed to the outside of the blower 1, and thus can easily remove one of the rear cover 21 and the front cover 22. After that, by the user using a tool to remove the other screw, the other of the rear cover 21 and the front cover 22 can be easily removed. In the blower 1, since the cover is screwed, while it is easy for the user to remove the cover using a tool, a configuration can be realized in which it is difficult for the cover to be easily removed even if a child touches it. Thus, in the present embodiment, a blower 1 with an easily removable cover can be realized.

[0044] Also, in the present embodiment, the cover attachment member 30 includes a rear attachment member 31 provided on the rear cover 21 side and a front attachment member 32 provided on the front cover 22 side. The first attachment screw S1 is exposed outside the fan 1, and the second attachment screw S2 is exposed outside the fan 1 when the rear attachment member 31 and the front attachment member 32 are removed. According to this configuration, since it is necessary to first remove the rear cover 21 (the first attachment screw S1) in order to remove the front cover 22 (the second attachment screw S2), it is possible to prevent the front cover 22 from being accidentally removed while realizing a fan with an easily removable cover.

[0045] Also, in the present embodiment, the annular portion 32a has a plurality of engaging portions 32e spaced apart in the circumferential direction thereof. Each of the rear cover 21 and the front cover 22 has a plurality of rear engaged portions 21e and front engaged portions 22e that are engaged with the plurality of engaging portions 32e. The front cover 22 is provided such that each of the plurality of front engaged portions 22e is arranged in a non-rotationally symmetric manner with respect to the circumferential direction of the annular portion 32a. According to this configuration, by engaging each of the rear engaged portions 21e and each of the front engaged portions 22e with each of the engaging portions 32e, the rear cover 21 and the front cover 22 can be securely attached to the annular portion 32a.

[0046] Furthermore, according to the above configuration, since each of the front engaged portions 22e of the front cover 22 is arranged in a non-rotationally symmetric manner with respect to the circumferential direction of the annular portion 32a as described above, even if the front cover 22 is attempted to be attached to the annular portion 32a in the wrong direction, each of the front engaged portions 22e of the front cover 22 does not face each of the engaging portions 32e (each of the front engaging portions 32e2), so that it is possible to prevent the front cover 22 from being attached to the annular portion 32a in the wrong direction.

[0047] Regarding the rear cover 21, in the present embodiment, since the concave opening 21b2 is provided only at the lower end of the rear second grill portion 21b of the rear cover 21, even if the rear cover 21 is mistakenly attached to the annular portion 32a in the wrong direction, the outer peripheral edge of the rear second grill portion 21b interferes with the upper portion of the rear neck portion 31c of the rear attachment member 31, and the rear cover 21 cannot be attached to the annular portion 32a. Therefore, it is possible to prevent the rear cover 21 from being attached in the wrong direction.

[0048] In addition, in the present embodiment, when it is desired to make the rear cover 21 and the front cover 22 easier to remove and facilitate the cleaning of both covers 21 and 22, the first mounting screw S1 and the second mounting screw S2 are removed, and the rear cover 21 and the front cover 22 are only positioned with respect to the annular portion 32a and the respective engaging portions 32e are engaged with the respective rear engaged portions 21e and the respective front engaged portions 22e. It is also possible to adopt a configuration in which both covers 21 and 22 are attached to the annular portion 32a. In this case, by filling the rear insertion hole 21H and the front insertion hole 32H1 in the manufacturing process of the fan 1, it is possible to prevent the user from misrecognizing that the first mounting screw S1 and the second mounting screw S2 are out of stock. Filling the rear insertion hole 21H and the front insertion hole 32H1 can be performed using an insert of the mold, so that each case 21 and 22 can be molded using a common mold.

[0049] Also, in the fan 1 of the present embodiment, the plurality of engaging portions 32e and the plurality of rear engaged portions 21e and the front engaged portions 22e are opposed to each other by attaching each of the rear cover 21 and the front cover 22 to the annular portion 32a in a positioned state and shifting them in the circumferential direction, and are engaged with each other by abutting against each other in a direction orthogonal to the circumferential direction in the opposed state. According to this configuration, by making the attachment mode of the rear cover 21 and the front cover 22 to the annular portion 32a in two steps in this way, the rear cover 21 and the front cover 22 can be surely attached to the annular portion 32a in the correct direction.

[0050] In addition, in the fan 1 of the present embodiment, each of the rear cover 21 and the front cover 22 has a rear first grill portion 21a and a side surface portion 22a that constitute an annular side surface, and a rear second grill portion 21b and a front grill portion 22b provided inside the side surface portion 22a. Each of the rear first grill portion 21a of the rear cover 21 and the front grill portion 22b of the front cover 22 has a plurality of beam-shaped portions 21b1, 22b1 that extend linearly and in parallel. According to this configuration, when cleaning the rear cover 21 and the front cover 22, it is possible to clean them with a cleaning brush or the like along the beam-shaped portions 21b1, 22b1 that extend linearly and in parallel, so that the rear cover 21 and the front cover 22 can be easily cleaned.

[0051] In addition, the fan 1 of the present embodiment is a double-reverse type in which the rotation directions of the rear impeller 25 and the front impeller 26 are different from each other. According to this configuration, it is possible to realize a double-reverse type fan 1 in which the cover can be easily removed.

[0052] Note that the embodiments described above are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalent scope thereof.

Explanation of Reference Numerals

[0053] 1 Fan 10 Main body 12 Control knob 14 Mounting portion 16 Rotating portion 16a Opening 20 Air blowing head 21 Rear cover 21C Central portion 21H Rear insertion hole 21M Rear mark 21a Rear first grill portion 21a1 Beam-shaped portion 21b Rear second grill portion 21b1 Beam-shaped portion 21b2 Concave opening 21e Rear engaged portion 22 Rear cover 22C Central part 22H Front screw hole 22M Front mark 22a Side surface part 22a1 Front micro cylinder part 22b Front grill part 22b1 Beam - shaped part 22e Front engaged part 25 Rear impeller 25a Rear rotating part 25b Rear blade part 26 Front impeller 26a Front rotating part 26b Front blade part 30 Cover mounting member 31 Rear mounting member 31H1 Rear screw hole 31H2 Neck - side insertion hole 31a Upper circular part 31b Rear wiring accommodation part 31c Rear neck part 31c1 Rear notch part 32 Front mounting member 32H1 Front insertion hole 32H2 Neck - side screw hole 32a Annular part 32b Central circular part 32c Front neck part 32c1 Front notch part 32c2 Neck - side micro cylinder part 32d Front wiring accommodation part 32e Engaging part 32e1 Rear engaging part 32e2 Front engaging part BS Rear start position FS Front start position M1 First mark M2 Second mark S1 First mounting screw S2 Second mounting screw S3 Third mounting screw θ1~θ8 Spreading angle

Claims

1. A fan having a pair of impellers, a cover attachment member having an annular portion and provided between the pair of impellers, a first cover attached to the cover attachment member by a first screw in a state of being positioned on the annular portion and covering one of the pair of impellers, a second cover attached to the cover attachment member by a second screw in a state of being positioned on the annular portion and covering the other of the pair of impellers, and the first screw and the second screw are attached to the cover attachment member independently of each other, and at least one of them is exposed to the outside of the fan, a fan.

2. The cover attachment member has a first attachment member provided on the first cover side and a second attachment member provided on the second cover side, the first screw is exposed to the outside of the fan, and the second screw is exposed to the outside of the fan when the first attachment member and the second attachment member are removed, The fan according to claim 1.

3. The annular portion has a plurality of engaging portions spaced apart in the circumferential direction thereof, each of the first cover and the second cover has a plurality of engaged portions to be engaged with the plurality of engaging portions, at least one of the first cover and the second cover is provided such that each of the plurality of engaged portions is not rotationally symmetric with respect to the circumferential direction, The fan according to claim 1.

4. The plurality of engaging portions and the plurality of engaged portions face each other by attaching each of the first cover and the second cover to the annular portion in a positioned state and shifting them in the circumferential direction, and are engaged with each other by abutting against each other in a direction orthogonal to the circumferential direction in the facing state, The fan according to claim 3.

5. Each of the first cover and the second cover has a side portion constituting an annular side surface and a bottom portion provided inside the side portion, each of the bottom portion of the first cover and the bottom portion of the second cover has a plurality of beam-like portions extending linearly and in parallel, The fan according to claim 1.

6. The pair of impellers are of a double-reverse type in which the rotation directions are different from each other, The fan according to any one of claims 1 to 5.

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