阅读说明：本技术 风扇引导单元 (Fan guide unit ) 是由 铃木琢真 于 2019-09-25 设计创作，主要内容包括：本发明的热交换器用的风扇引导单元具备：风扇引导件(5),其具有以沿着周向的方式在开口部的周缘设置的嵌合部(10)和被设置于嵌合部(10)且向与周向交叉的方向突出的至少一个突起部(11)；以及风扇罩(6),其具有与风扇引导件(5)的嵌合部(10)对应地设置的被嵌合部(13)。在风扇罩(6)的被嵌合部(13)设置有与风扇引导件(5)的突起部(11)对应地设置的至少一个贯通孔(14)。(The fan guide unit for a heat exchanger of the present invention includes: a fan guide (5) having a fitting section (10) provided along the circumferential direction at the periphery of the opening section, and at least one protrusion section (11) provided in the fitting section (10) and protruding in a direction intersecting the circumferential direction; and a fan cover (6) having an engaged portion (13) provided corresponding to the engaging portion (10) of the fan guide (5). At least one through hole (14) provided corresponding to the protrusion (11) of the fan guide (5) is provided in the fitted portion (13) of the fan cover (6).)

1. A fan guide unit for a heat exchanger, comprising:

a fan guide having: a fitting portion provided along a circumferential direction at a periphery of the opening portion of the fan guide; and at least one protrusion portion provided to the fitting portion and protruding in a direction intersecting the circumferential direction; and

a fan cover having a fitted portion provided corresponding to the fitting portion of the fan guide,

at least one through hole provided corresponding to the protrusion of the fan guide is provided in the fitted portion of the fan cover.

2. The fan guide unit of claim 1,

the opening portion of the fan guide is substantially circular,

the fitting portion extends in a radial direction from a peripheral edge of the opening portion,

the protrusion extends from a tip of the fitting portion in the radial direction.

3. The fan guide unit of claim 2,

the protrusion of the fan guide has a substantially rectangular shape in the cross section in the circumferential direction,

the circumferential width of the protrusion of the fan guide is greater than the radial length.

4. The fan guide unit according to claim 2 or 3,

the fan cover has an annular portion, the fitted portion is provided at a peripheral edge of the annular portion along a circumferential direction,

the circumferential width of the through hole of the fan cover is larger than the circumferential width of the protrusion of the fan guide on the fitting portion side.

5. The fan guide unit of claim 2,

the fan cover has an annular portion, the fitted portion is provided at a peripheral edge of the annular portion along a circumferential direction,

with respect to the protrusion portion of the fan guide, in a cross section in the circumferential direction, a width in the circumferential direction on a distal end side is larger than a width in the circumferential direction on the fitting portion side,

the circumferential width of the through hole of the fan cover is larger than the circumferential minimum width of the protrusion of the fan guide and smaller than the circumferential maximum width of the protrusion of the fan guide.

6. The fan guide unit according to any one of claims 1 to 5,

the protrusion of the fan guide has a rib, and at least a part of the rib is exposed from the fan cover when the fan cover is attached to the fan guide.

7. The fan guide unit of claim 6,

the rib extends in the circumferential direction, and the rib is entirely exposed from the fan cover when the fan cover is attached to the fan guide.

8. The fan guide unit according to any one of claims 1 to 7,

the fan cover is made of an elastic body,

the protrusion of the fan guide is located at a lower portion of the fan guide.

9. The fan guide unit of claim 8,

the fan guide has 3 protrusions, and the 3 protrusions are provided to a lower half area of the fan guide.

Technical Field

The present invention relates to a fan guide unit.

Background

A cooling fan that draws cooling air to increase a heat dissipation amount is disposed behind a heat exchanger (e.g., a radiator) of a vehicle. Further, a fan guide unit is attached to the rear surface of the radiator, and the cooling air sucked by the cooling fan is rectified, thereby improving the air blowing efficiency to the radiator.

The fan guide unit has a fan guide and a fan cover. The fan guide is attached to cover the rear surface of the radiator, and has a substantially circular opening that guides the cooling air from the radiator to the rear. The fan cover has an annular portion and is attached to the opening portion of the fan guide. The fan cover connects the fan guide and a fan ring (not shown) surrounding the cooling fan, thereby preventing leakage of cooling air.

In patent document 1, the fan cover is attached to the opening of the fan guide by fitting a raised strip formed along the periphery of the opening of the fan guide into a clip formed along the periphery of the fan cover. Further, the rotation of the fan cover due to vibration of the engine or the like is suppressed by fitting the fitting portion of the fan cover into the recessed portion that is provided on the front side (radiator side) of the raised portion of the fan guide and is recessed toward the center.

In patent document 2, a fan cover is attached to an opening of a fan guide by fitting a fitting portion formed along a peripheral edge of the opening of the fan guide to a plurality of stoppers provided in the fan cover at equal intervals in a circumferential direction. Further, the hemispherical bulging portion provided on the stopper of the fan cover is fitted into the mounting hole provided on the fitting portion of the fan guide, thereby preventing the fan cover from coming off in the centrifugal direction.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2017-81244

Patent document 2: japanese laid-open patent publication No. 2012-97589

Disclosure of Invention

Technical problem to be solved by the invention

However, in the fan cover mounting structure of patent document 2, if a force acts in the rotational direction, the bulging portion of the fan cover may be disengaged from the mounting hole of the fan guide and rotated. In the fan cover mounting structure of patent document 1, when a strong force acts in the rotational direction, the fitting portion of the fan cover may climb around the recess of the fan guide and rotate. Therefore, there is still room for improvement in a structure for suppressing rotation of the fan cover.

The invention aims to provide a fan guide unit capable of restraining rotation of a fan cover.

Means for solving the problems

A fan guide unit for a heat exchanger according to an aspect of the present invention includes:

a fan guide having: a fitting portion provided along a circumferential direction at a periphery of the opening portion of the fan guide; and at least one protrusion portion provided to the fitting portion and protruding in a direction intersecting the circumferential direction; and

a fan cover having a fitted portion provided corresponding to the fitting portion of the fan guide,

at least one through hole provided corresponding to the protrusion of the fan guide is provided in the fitted portion of the fan cover.

According to the above configuration, the protrusion provided in the fan guide is fitted in the through hole provided in the fan cover, whereby the rotation of the fan cover can be suppressed.

Further, the opening of the fan guide may be substantially circular,

the fitting portion extends in a radial direction from a peripheral edge of the opening portion,

the protrusion extends from a tip of the fitting portion in the radial direction.

According to the above configuration, since the direction in which the fitted portion is fitted to the fitting portion and the direction in which the through hole is fitted to the protrusion portion are the same radial direction, the workability of mounting the fan cover is improved.

Further, the protrusion of the fan guide may have a substantially rectangular shape in the cross section in the circumferential direction,

the circumferential width of the protrusion of the fan guide is greater than the radial length.

According to the above configuration, the rigidity of the protruding portion in the rotational direction can be improved. Further, the projection can be prevented from coming off in the radial direction from the through hole.

The fan cover may have an annular portion, the fitted portion may be provided along a circumferential direction of the annular portion,

the circumferential width of the through hole of the fan cover is larger than the circumferential width of the fitting portion side of the protruding portion of the fan guide.

According to the above configuration, even if a circumferential positional deviation or a shape error occurs between the through hole and the protrusion, the protrusion can be fitted into the through hole. Further, the fitting portion and the fitted portion are fitted to both circumferential ends of the through hole. Therefore, even if a gap exists between the protrusion and the through hole, the gap is closed at the surrounding fitting portion and fitting portion, and therefore, the cooling air can be prevented from leaking from the gap.

The fan cover may have an annular portion, the fitted portion may be provided along a circumferential direction of the annular portion,

with respect to the protrusion portion of the fan guide, in a cross section in the circumferential direction, a width in the circumferential direction on a distal end side is larger than a width in the circumferential direction on the fitting portion side,

the circumferential width of the through hole of the fan cover is larger than the circumferential minimum width of the protrusion of the fan guide and smaller than the circumferential maximum width of the protrusion of the fan guide.

According to the above configuration, even if a circumferential positional deviation or a shape error occurs between the through hole and the protrusion, the protrusion can be fitted into the through hole. Further, since the fitting portion and the fitted portion are fitted to both ends in the circumferential direction of the through hole, even if a gap exists between the protrusion portion and the through hole, the gap is closed at the surrounding fitting portion and the fitted portion, and therefore, the cooling air can be prevented from leaking from the gap. In addition, the projection can be further prevented from coming off in the radial direction from the through hole.

The projection of the fan guide may have a rib, and at least a part of the rib may be exposed from the fan cover when the fan cover is attached to the fan guide.

According to the above configuration, whether or not the fan cover is correctly attached to the fan guide can be determined by checking whether or not the rib is visible after the fan cover is attached.

The rib may extend in the circumferential direction, and the entire rib may be exposed from the fan cover when the fan cover is attached to the fan guide.

According to the above configuration, since the entire rib extending in the circumferential direction is exposed from the fan cover, the rib can be easily seen. Further, the projection can be prevented from coming off in the radial direction from the through hole.

In addition, the fan cover may be made of an elastic body,

the protrusion of the fan guide is located at a lower portion of the fan guide.

According to the above configuration, the mounting work performed while extending the fan cover itself is generally performed from the lower portion of the fan guide. Therefore, the fan cover can be easily attached by inserting the protrusion into the through hole and hooking the protrusion into the through hole at the initial stage of the attachment.

The fan guide may have 3 protrusions, and the 3 protrusions may be provided in a lower half of the fan guide.

According to the above configuration, since the fan guide has 3 protruding portions, the rotation of the fan cover can be further suppressed. In addition, in the initial stage of installation, 3 protrusions are inserted into and hooked with 3 through holes, so that the fan cover can be installed more easily.

The lower half of the fan guide is located below the vertical center of the fan guide.

Effects of the invention

According to the present invention, it is possible to provide a fan guide unit capable of suppressing rotation of a fan cover.

Drawings

Fig. 1 is a perspective view for explaining the overall structure of a heat exchanger to which a fan guide unit according to the present embodiment is attached.

Fig. 2A is a diagram illustrating the fan guide unit according to the present embodiment.

Fig. 2B is a view showing a state (fan guide) in which the fan cover is detached from the fan guide unit of fig. 2A.

Fig. 3A is a partially enlarged perspective view of a lower portion of the fan guide unit of fig. 2A.

Fig. 3B is a sectional a-a perspective view of the fan guide unit of fig. 3A.

Fig. 4 is a schematic view for explaining a projection of the fan guide.

Fig. 5A is a perspective view of the fan guide unit of fig. 3B cut away B-B.

Fig. 5B is a sectional perspective view showing a state (fan guide) where the fan cover is detached from the fan guide unit of fig. 5A.

Fig. 6A is a partially enlarged perspective view of a lower portion of the fan guide unit according to the modification.

Fig. 6B is a C-C sectional view of the fan guide unit of fig. 6A.

Fig. 7A is a schematic diagram for explaining a modification of the protrusion.

Fig. 7B is a schematic diagram for explaining another modification of the protrusion.

Fig. 7C is a schematic diagram for explaining still another modification of the protrusion.

Detailed Description

Hereinafter, an embodiment of the present invention (hereinafter, referred to as the present embodiment) will be described with reference to the drawings. For convenience of explanation, the dimensions of the components shown in the drawings may be different from the actual dimensions of the components.

In the description of the present embodiment, for convenience of description, the terms "left-right direction", "up-down direction", and "front-back direction" are appropriately mentioned. These directions are opposite directions set for the fan guide unit 4 shown in fig. 1. These directions correspond to directions in a state where the heat exchanger 1 mounted with the fan guide unit 4 is disposed in the vehicle. Here, the "left-right direction" is a direction including the "left direction" and the "right direction". The "up-down direction" is a direction including an "up direction" and a "down direction". The "front-rear direction" is a direction including the "front direction" and the "rear direction". The front-rear direction is a direction orthogonal to the up-down direction. The left-right direction is a direction orthogonal to the front-back direction and the up-down direction. In the drawings, an arrow U indicates an upward direction, an arrow D indicates a downward direction, an arrow L indicates a left direction, an arrow R indicates a right direction, an arrow F indicates a front direction, and an arrow B indicates a rear direction.

Integral structure of heat exchanger with fan guide unit

Fig. 1 is a perspective view for explaining the overall structure of a heat exchanger 1 to which a fan guide unit 4 according to the present embodiment is attached.

The heat exchanger 1 is disposed, for example, at the front of a vehicle (for example, in an engine compartment), and cools compressed air and cooling water circulating in the heat exchanger 1 by cooling air introduced from the front of the vehicle. A cooling fan (not shown) for sucking cooling air is disposed behind the heat exchanger 1 to increase the amount of heat radiation. The fan guide unit 4 is disposed between the heat exchanger 1 and the cooling fan in the front-rear direction. The fan guide unit 4 is installed at the rear surface of the heat exchanger 1. The cooling air is taken in from the front of the heat exchanger 1, passes through the heat exchanger 1 and the fan guide unit 4 in this order, and flows out to the rear via the cooling fan. The fan guide unit 4 rectifies the cooling air drawn by the cooling fan to increase the blowing efficiency of the cooling air to be sent to the heat exchanger 1 (i.e., the cooling efficiency of the heat exchanger 1).

The heat exchanger 1 has an intercooler 2 and a radiator 3. The intercooler 2 and the radiator 3 are sequentially provided in the flow direction of the cooling air. The intercooler 2 cools compressed air from a supercharger that delivers compressed air to the engine. The radiator 3 cools cooling water for cooling a heat source such as an engine. The heat exchanger 1 is not limited to the heat exchanger including the intercooler 2 and the radiator 3. The intercooler 2 is disposed on the front side of the radiator 3, but may be disposed on the rear side of the radiator 3.

The fan guide unit 4 has a fan guide 5 and a fan cover 6. The fan guide 5 is attached to cover the rear surface of the radiator 3, and rectifies the cooling air drawn by the cooling fan. The fan cover 6 connects the fan guide 5 and a fan ring (not shown) surrounding the cooling fan, and prevents leakage of cooling air.

< integral Structure of Fan guide Unit >

Next, the structure of the fan guide unit 4 of the present embodiment will be described mainly with reference to fig. 2A to 2B.

Fig. 2A is a diagram illustrating the fan guide unit 4 according to the present embodiment. Fig. 2B is a view showing a state (fan guide 5) in which the fan cover 6 is detached from the fan guide unit 4 of fig. 2A. Fig. 2A and 2B are views viewed from the rear.

The fan guide 5 is made of synthetic resin and has a substantially square shape in front view. A substantially circular opening 8 for guiding the cooling air from the radiator 3 rearward is provided in the rear surface of the fan guide 5 on the cooling fan side. The center of the opening 8 is slightly offset downward from the center of the rear surface of the fan guide 5. The front surface of the fan guide 5 on the radiator 3 side is opened as a passage for cooling air. The fan guide 5 forms a space for rectifying the cooling air drawn by the cooling fan by a guide body 9 connecting the end periphery on the radiator 3 side and the periphery of the opening 8. The direction along the periphery of the opening 8 is sometimes referred to as "circumferential direction", and the direction along the radius of the opening 8 is sometimes referred to as "radial direction". In the "radial direction", a direction from the outside of the opening 8 toward the center position is sometimes referred to as a "center direction", and a direction from the center position toward the outside of the opening 8 is sometimes referred to as a "centrifugal direction". In the drawings, arrow C indicates the circumferential direction, and arrow RA indicates the radial direction.

The fan guide 5 has a flange 7 at the end periphery on the radiator 3 side. The flange portion 7 is provided with a mounting hole and a mounting portion. The fan guide 5 is fixed to the rear surface of the heat sink 3 at the flange portion 7 by bolts or the like.

The fan cover 6 is attached to the periphery of the opening 8 of the fan guide 5. The fan cover 6 is made of an elastic body (e.g., rubber).

The fan guide 5 has a substantially square shape in front view corresponding to the shape of the rear surface of the heat sink 3, but is not limited thereto. The shape of the end portion attached to the heat exchanger 1 is not particularly limited as long as the shape corresponds to the shape of the heat exchanger 1. The shape and position of the opening 8 are not limited to these. The shape and position of the cooling fan and the fan ring are not particularly limited as long as they correspond to the shape and position.

Mounting structure of fan guide and fan cover

Next, an installation structure of the fan guide 5 and the fan cover 6 according to the present embodiment will be described mainly with reference to fig. 3A to 5B.

Fig. 3A is a partially enlarged perspective view of a lower portion of the fan guide unit 4 of fig. 2A. Fig. 3B is a sectional a-a perspective view of the fan guide unit 4 of fig. 3A. Fig. 4 is a schematic view for explaining a projection of the fan guide. Fig. 4 is a schematic diagram showing a circumferential cross-sectional shape of the protrusion. Fig. 5A is a perspective view of the fan guide unit 4 of fig. 3B in a section B-B.

Fig. 5B is a sectional perspective view showing a state (fan guide 5) where the fan cover 6 is detached from the fan guide unit 4 of fig. 5A.

As shown in fig. 3B, the fan guide 5 includes a fitting portion 10 and a protruding portion 12 at the periphery of the opening 8. The fitting portion 10 is provided at the periphery of the opening 8 so as to extend in the centrifugal direction and along the circumferential direction. The distal end portion of the fitting portion 10 is bent rearward, and has a substantially L-shaped cross section perpendicular to the circumferential direction. The protruding portion 12 is provided at a position on the peripheral edge of the opening 8 on the front side of the fitting portion 10, extending in the centrifugal direction and extending in the circumferential direction.

As shown in fig. 3B, the fan cover 6 has an annular portion 6a and a fitted portion 13. The annular portion 6a is configured to surround a part of the fan ring. The rear portion of the annular portion 6a extends toward the center, and the tip thereof is fitted to the fan ring. The fitted portion 13 is provided on the periphery of the distal end of the annular portion 6 a. The fitted portion 13 includes a front fitted portion 13a and a rear fitted portion 13b extending in the center direction and arranged along the circumferential direction. The fitting target portion 13 is fitted to the fitting portion 10 so that the fitting portion 10 is sandwiched from the front and rear by the front fitting target portion 13a and the rear fitting target portion 13 b. The rear fitted portion 13b has a distal end bent forward, has a substantially L-shaped cross section perpendicular to the circumferential direction, and engages with the substantially L-shaped distal end of the fitting portion 10.

The fitting portion 10 of the fan guide 5 is fitted so as to be sandwiched from the front and the rear by the fitted portion 13 of the fan cover 6. Such a mounting structure can suppress the backward movement of the fan cover 6 from the fan guide 5. Further, since the tip of the fitting portion 10 is engaged with the tip of the rear-side fitted portion 13b, the fan cover 6 can be prevented from coming off from the fan guide 5 in the centrifugal direction. Further, since the protruding portion 12 is provided in parallel with the fitting portion 10, the protruding portion 12 can guide the fitted portion 13 in the center direction when the fitted portion 13 is fitted to the fitting portion 10.

In the present embodiment, the fan guide 5 further includes at least one protrusion 11 provided in the fitting portion 10, and the fan cover 6 includes at least one through hole 14 provided in the fitted portion 13 corresponding to the protrusion 11. The rotation of the fan cover 6 due to engine vibration and the like can be suppressed by the protrusion 11 and the through hole 14.

For example, as shown in fig. 3A, the fan guide 5 has a plurality of (three in this example) protrusions 11. Three protrusions 11 are provided in the lower half area of the fan guide 5. One projection 11 is provided at the lowermost portion (an example of the lower portion) of the peripheral edge of the opening 8 (see fig. 2B), and two projections 11 are provided at a predetermined interval on the left and right sides thereof. The fan cover 6 has a plurality of (three in this example) through holes 14 corresponding to the protrusions 11 of the fan guide 5.

As shown in fig. 4, the protrusion 11 has a substantially rectangular shape in a cross section in the circumferential direction, and is formed such that a width W2 in the circumferential direction is larger than a length L1 in the radial direction. As shown in fig. 5A and 5B, the protrusion 11 has a front-rear direction width W1 equal to the front-rear direction width W0 of the tip of the fitting 10 in the radial and front-rear direction cross sections, and protrudes from the tip of the fitting 10 in the centrifugal direction over a predetermined length in the circumferential direction.

As shown in fig. 4, the through hole 14 is formed so that the circumferential width W3 is greater than the circumferential width W2 of the protrusion 11 of the fan guide 5 on the fitting portion 10 side. The width of the through hole 14 in the front-rear direction is formed to be the same as the width of the protrusion 11 in the front-rear direction. In a state where the fan cover 6 is attached to the fan guide 5, the width of the through hole 14 in the front-rear direction is the same as the width of the protrusion 11 in the front-rear direction, and therefore the protrusion 11 is fitted into the through hole 14.

In the work of attaching the fan cover 6 to the fan guide 5, first, the worker determines the position of the fan cover 6 with respect to the rotational direction (circumferential direction) of the fan guide 5 so that the through hole 14 corresponds to the protrusion 11. Next, the projection 11 located at the lowermost position of the fan guide 5 is fitted into the through hole 14, and the fitted portion 13 is fitted into the fitting portion 10 so that the fitted portion 13 sandwiches the fitting portion 10 from the front and rear directions around the projection. The operator inserts the through hole 14 into the protrusion 11 while extending the fan cover 6 in the front-rear direction against the restoring force, and fits the protrusion 11 into the through hole 14 while restoring the fan cover 6, as necessary.

Next, the operator extends the fan cover 6 in the circumferential direction against the restoring force as necessary, and fits the fitted portion 13 to the fitting portion 10 from below toward above while restoring the fan cover 6. Further, the remaining two protrusions 11 are fitted into the through-hole 14 in the middle, but even if the positions of the two protrusions 11 and the through-hole 14 are slightly shifted in the circumferential direction, the width of the through-hole 14 in the circumferential direction is wider than the width of the protrusion 11, and therefore the protrusion 11 and the through-hole 14 can be fitted. Further, the fan cover 6 can be attached to the fan guide 5 by fitting all the fitting portions 13 in the circumferential direction to the fitting portions 10.

In this way, in the present embodiment, the protrusion 11 provided in the fan guide 5 is fitted in the through hole 14 provided in the fan cover 6, thereby suppressing the rotation of the fan cover 6.

Further, since the protrusion 11 extends in the centrifugal direction from the end of the fitting portion 10, the fitting direction of the through hole 14 and the protrusion 11 is the same direction as the fitting direction of the fitted portion 13 and the fitting portion 10, and the mounting workability of the fan cover 6 is improved.

Further, since the protrusion 11 has a substantially rectangular shape in a cross section in the circumferential direction and the circumferential width is larger than the radial length, the rigidity of the protrusion 11 in the rotational direction can be improved. Further, the protrusion 11 can be prevented from coming off from the through hole 14 in the center direction.

Further, since the circumferential width of the through hole 14 is larger than the circumferential width of the fitting portion side of the protrusion 11, the protrusion 11 can be fitted into the through hole 14 even if a circumferential positional shift or a shape error occurs between the through hole 14 and the protrusion 11. The fitting portion 10 and the fitted portion 13 are fitted to both circumferential ends of the through hole 14. Therefore, even if there is a gap between the protrusion 11 and the through hole 14, the gap is closed by the surrounding fitting portion 10 and the fitting portion 13, and therefore, the cooling air can be prevented from leaking from the gap.

Further, since the fan guide 5 has three protrusions 11, the rotation of the fan cover 6 can be further suppressed. In addition, three protrusions 11 are provided in the lower half area of the fan guide 5. Since the mounting work performed while extending the fan cover 6 itself is performed from the lower portion of the fan guide 5, the protrusion 11 is inserted into and hooked in the through hole 14 at the initial stage of mounting, and the fan cover can be easily mounted.

< modification of fan guide unit >

Next, a modified example of the fan guide unit 4 will be described. Fig. 6A is a partially enlarged perspective view of a lower portion of the fan guide unit 4' according to the modification. Fig. 6B is a C-C sectional view of the fan guide unit 4' of fig. 6A. In the description of the modified example, the same reference numerals as those used in the description of the present embodiment are used to designate the same components, and the description thereof will be omitted for convenience of description. Modification 1 is different from fan guide 5 of the present embodiment in that protrusion 11 'of fan guide 5' has rib 15.

The projection 11 'of the fan guide 5' has a rib 15 extending in the circumferential direction on the fan cover 6 side surface. The ribs 15 are provided at the following positions: when the fan cover 6 is attached to the fan guide 5', the entire rib 15 is exposed from the fan cover 6 in a state where the fitted portion 13 is normally fitted to the fitting portion 10.

Since the projection 11' has the rib 15, the worker who performs the mounting work can confirm whether or not the rib 15 is visible after the fan cover 6 is mounted. Therefore, the operator can determine whether or not the fan cover 6 is correctly attached to the fan guide 5'. Further, the rib 15 can prevent the projection 11' from coming off from the through hole 14 in the radial direction.

The number, arrangement location, and shape of the ribs 15 are not particularly limited as long as at least a part thereof is exposed from the fan cover 6 when the fan cover 6 is attached to the fan guide 5'.

< modification of projecting portion of fan guide >

Next, a modified example of the protrusion 11 of the fan guide 5 will be described. Fig. 7A to 7C are schematic views for explaining modifications of the protrusions 11A to 11C. Fig. 7A to 7C are schematic diagrams showing the circumferential cross-sectional shapes of the protrusions 11A to 11C.

In the circumferential cross section of the projection 11A in fig. 7A, the circumferential width W6 on the distal end side is wider than the circumferential width W5 on the fitting portion 10 side, and is T-shaped. The through hole 14A is formed such that, in a circumferential cross section, a circumferential width W4 is greater than a circumferential width W5 of the projection 11A on the fitting portion 10 side and is smaller than a circumferential width W6 on the distal end side.

In a cross section in the circumferential direction of the projection 11B in fig. 7B, the width in the circumferential direction gradually increases from the fitting portion 10 side toward the distal end side. The through hole 14B is formed such that, in a circumferential cross section, a circumferential width W7 is larger than a circumferential width W8 of the projection 11A on the fitting portion 10 side and smaller than a circumferential width W9 on the distal end side.

In the cross section in the circumferential direction of the projection 11C in fig. 7C, the width in the circumferential direction is the same from the fitting portion 10 side to a predetermined position in the centrifugal direction, and the width in the circumferential direction gradually increases from the predetermined position toward the distal end side. The through hole 14C is formed such that, in a circumferential cross section, the circumferential width W10 is greater than the circumferential width W11 of a predetermined position of the protrusion 11A and smaller than the circumferential width W12 on the distal end side.

In this way, in the circumferential cross section of the projection portions 11A to 11C of the fan guide 5, the circumferential width on the distal end side is larger than the circumferential width on the fitting portion 10 side. The circumferential width of the through holes 14A to 14C of the fan cover 6 is larger than the circumferential minimum width of the protrusions 11A to 11C of the fan guide and smaller than the circumferential maximum width of the protrusions 11A to 11C of the fan guide 5. Therefore, even if a circumferential positional deviation or a shape error occurs between the through holes 14A to 14C and the protrusions 11A to 11C, the protrusions 11A to 11C can be fitted into the through holes 14A to 14C. Further, since the fitting portion 10 and the fitted portion 13 are fitted to both ends of the through holes 14A to 14C in the circumferential direction, even if there is a gap between the protrusion portions 11A to 11C and the through holes 14A to 14C, the gap is closed by the surrounding fitting portion 10 and the fitted portion 13, and therefore, the cooling air can be prevented from leaking from the gap. Further, the projections 11A to 11C can be further prevented from coming off in the centrifugal direction from the through holes 14A to 14C.

< other embodiments >

While the embodiments of the present invention have been described above, it is needless to say that the technical scope of the present disclosure should not be construed as being limited by the description of the embodiments. It will be understood by those skilled in the art that the present embodiment is merely an example, and various modifications of the embodiment can be made within the scope of the invention described in the claims. The technical scope of the present invention should be determined based on the scope of the invention described in the claims and the equivalent scope thereof.

In the above embodiment, the fan guide 5 has the protruding portions 12 on the peripheral edge of the opening 8, but the present invention is not limited to this. The fan guide 5 may not have the protruding strip 12.

In the above embodiment, the plurality of protrusions 11 have the same shape, but the present invention is not limited thereto. The plurality of protrusions 11 may have different shapes.

In the above embodiment, the protrusion 11 is provided at the lower portion of the fan guide 5, but the present invention is not limited thereto. For example, when the fan cover 6 is attached from above the fan guide 5, the protrusion 11 may be provided on the upper portion of the fan guide 5. The fan guide 5 has 3 protrusions 11, but is not limited thereto. For example, the fan guide 5 may have one or two protrusions or 4 or more protrusions. Further, the plurality of (three in this example) protrusions 11 are provided in the lower half of the fan guide 5, but the present invention is not limited thereto. For example, one projection 11 may be provided in a lower half of the fan guide 5, and the remaining projections 11 may be provided in an upper half of the fan guide 5.

In the above embodiment, the protrusion 11 is formed to protrude from the tip of the fitting portion 10 in the centrifugal direction perpendicular to the circumferential direction, but is not limited thereto. For example, the projection may be projected in a direction inclined at a predetermined angle with respect to the radial direction. It is preferable that the protrusion 11 does not protrude into the space formed inside the guide body 9. When the protrusion 11 protrudes into the space formed inside the guide body 9, it preferably protrudes into a portion that does not obstruct the flow of the cooling air.

The present application is based on japanese patent application No. 2018-180062, filed on 26.9.2018, the contents of which are hereby incorporated by reference.