JP3977912B2 - Cooling device and shroud casing - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cooling device that cools a heat exchanger or the like, and more particularly to a technique that is effective for improving aerodynamic performance and reducing noise of a cooling fan.
[0002]
[Background Art and Problems to be Solved by the Invention]
As this type of cooling device, for example, those shown in FIGS. 6 and 7 are known.
In these drawings, reference numeral 1 is a shroud casing, 2 is a heat exchanger typified by a radiator or the like, 3 is a cooling fan, 4 is a driving device typified by a motor or the like, and a, b, and c are airflows. .
[0003]
This cooling device cools a shroud casing 1 provided on the downstream side of the heat exchanger 2 by rotating the cooling fan 3 by the driving device 4 to generate an air flow a in the upstream air.
However, when the cooling fan 3 rotates, the air flow a swirls in the same direction as the fan rotation and flows in the axial direction and the diagonal flow direction. In FIG. 7, the turbulence (air flow) c as shown in FIG.
This turbulence of the airflow becomes lost energy in the cooling system, which causes a problem that the aerodynamic performance of the fan is lowered and the noise is increased.
[0004]
The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a shroud casing and a cooling device that can suppress the turbulence of the airflow, improve the aerodynamic performance of the cooling fan, and reduce noise. .
[0005]
[Means for Solving the Problems]
The present invention employs the following configuration in order to solve the above problems.
That is, the cooling device according to claim 1 includes a cooling fan, a casing main body arranged to extend upstream from the periphery of the cooling fan, and a downstream end of the casing main body from the downstream end to the downstream in the axial direction. It is provided so as to protrude and has an inner diameter that is larger than the outer diameter of the cooling fan and gradually increases in diameter toward the downstream side in the axial direction. The upstream side of the inner peripheral surface forms a convex surface, whereas the downstream side is a concave surface. And a shroud casing having a diffuser having an S-shaped alphabet, and a driving device for rotationally driving the cooling fan, wherein the cooling fan is partially overlapped in the diffuser. It is what.
[0006]
In such a configuration, even if the airflow in the casing body becomes a swirling flow due to the rotation of the cooling fan, the swirling flow is controlled in the flow direction along the inner peripheral surface of the diffuser inclined in the discharge angle direction. Since it will be guided to the downstream side, generation | occurrence | production of the vortex | eddy_current in a shroud casing exit part is suppressed effectively. Therefore, the aerodynamic performance and noise reduction of the cooling fan can be achieved.
[0007]
A shroud casing according to a second aspect is a shroud casing used in the cooling device according to the first aspect, wherein the casing main body is arranged so as to extend upstream from the periphery of the cooling fan, and the casing main body. A diffuser provided at the downstream end so as to protrude downstream in the axial direction from the downstream end, and the diffuser has a diameter larger than the outer diameter of the cooling fan and gradually increases in diameter toward the downstream side in the axial direction. It has an inner diameter, and the upstream side of the inner peripheral surface forms a convex surface, whereas the downstream side forms a concave surface and forms an S-shape of the alphabet .
[0008]
Even in such a configuration, the generation of vortex at the shroud casing outlet is effectively suppressed as described above, so that the aerodynamic performance and noise reduction of the cooling fan can be achieved.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a cooling device according to the present invention will be described with reference to FIGS.
In these drawings, reference numeral 10 is a shroud casing, 20 is a heat exchanger, 30 is a cooling fan, 40 is a driving device, and a and b are airflows.
[0010]
The basic structure of the present cooling device is similar to the conventional one, in which a shroud casing 10 is provided on the downstream side of a heat exchanger 20 typified by a radiator or the like, and a driving device 40 typified by a motor or the like in the shroud casing 10. Thus, the airflow a generated by rotating the cooling fan 30 passes through the heat exchanger 20 to cool the airflow (see FIG. 1).
[0011]
The shroud casing 10 includes a casing body 11 disposed in a state in which the heat exchanger 20 is included on one end side (upstream side) or a state in which one end (upstream end) faces the heat exchanger 20, and the casing body 11. The other end side (downstream end) of the diffuser 12 is provided, and the casing body 11 and the diffuser 12 have inner diameters larger than the outer diameter of the cooling fan 30.
[0012]
As shown in FIG. 3, the diffuser 12 is provided with a mounting flange 13 on the inlet side (upstream side) having a smaller opening area than the outlet side (downstream side), and a plurality of diffusers 12 are machined in the circumferential direction of the mounting flange 13. It is attached to the downstream end of the casing body 11 by a mounting bolt (not shown) that is screwed into the bolt hole 14.
[0013]
In addition, on the back surface (outer peripheral surface) of the diffuser 12, a number of reinforcing plates 15 for connecting the mounting flange 13 and the diffuser 12 as reinforcing members are appropriately provided in the circumferential direction.
[0014]
The diffuser 12 in the present embodiment is the same as a normal diffuser in the configuration in which the inner diameter gradually increases from the upstream side to the downstream side, but the diffuser wall 16 is gentle in the cross section along the axial direction. It is characterized by being curved so as to form an S-shape.
[0015]
That is, as shown in FIG. 2, the diffuser wall 16 is opposite to each other so that the inner peripheral surface of the upstream portion 16a is convex while the inner peripheral surface of the downstream portion 16b is concave. These are formed so as to form a circular arc surface, and are formed so as to form a smooth continuous surface so as to form a so-called alphabet S-shape.
[0016]
In other words, the upstream portion 16a connected to the downstream end of the casing body 11 has a center of curvature O1 outside the diffuser 12, and the downstream portion 16b connected to the upstream portion 16a and extending to the outlet side. On the contrary, the diffuser 12 has the center of curvature O2 inside.
[0017]
These curvature radii differ depending on the resistance of the heat exchanger 20, but it is preferable to set the curvature radii so as not to cause the resistance of the fan discharge flow. The inventors of the present application have obtained R30 to R60 as experimental results. It has been confirmed that the range is the optimal radius of curvature.
In this embodiment, both are set to R40.
[0018]
Further, the tangent L to the outer peripheral surface of the downstream portion 16b passing through the intersecting portion 17 between the upstream end of the diffuser wall 16 and the mounting flange 13 has an inclination angle (θ in FIG. 4) that matches the fan discharge flow angle. With this configuration, the fan discharge flow can be made smoother.
In the present embodiment, that the inclination angle θ set to 45 ° is Figure shown.
[0019]
Note that the diffuser 12 may be an integral type, as shown in FIG. 5, a two-divided type interconnected at the dividing line P, or an appropriate number of divided types.
[0020]
Therefore, in the cooling device having such a configuration, as shown in FIG. 1, the airflow a generated by the rotational drive of the cooling fan 30 passes through the heat exchanger 20 and cools the refrigerant. It turns in the same direction as the fan rotation and passes through the diffuser 12 in the axial and diagonal flow directions.
[0021]
At this time, the swirling flow is guided to the downstream side while controlling the flow direction along the inner peripheral surface of the diffuser wall 16 inclined in the discharge angle direction, so that the swirling flow becomes a flow like an air flow b. It is delivered from the outlet of the casing 10.
Thereby, generation | occurrence | production of the vortex | eddy_current in the exit part of the shroud casing 11 can be suppressed effectively, and the aerodynamic performance of the cooling fan 30 and noise reduction can be aimed at.
[0022]
【The invention's effect】
As is clear from the above description, according to the present invention, the following effects can be obtained.
(A) In the cooling device according to claim 1, even if the airflow in the casing main body becomes a swirling flow by the rotation of the cooling fan, the swirling flow is along the inner peripheral surface of the diffuser inclined in the discharge angle direction. for being controlled in the direction of flow will be guided to the downstream side, to effectively suppress the generation of the vortex flow in the shroud casing outlet portion, improvement of the aerodynamic performance of the cooling fan and low noise cooling device Can be provided.
[0023]
(B) In the shroud casing according to claim 2, as in the case (a), since the generation of vortex at the shroud casing outlet portion can be effectively suppressed, the aerodynamic performance of the cooling fan is enhanced, and the noise is reduced. It is possible to provide a shroud casing that can be made simple .
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an embodiment of a cooling device according to the present invention.
FIG. 2 is a view taken along line AA in FIG.
3A is a front view of the diffuser shown in FIG. 1, and FIG. 3B is a longitudinal sectional view of the diffuser.
FIG. 4 is an enlarged view of a main part of FIG.
FIG. 5 is a perspective view showing an example of another embodiment of a diffuser according to the present invention.
FIG. 6 is a schematic configuration diagram showing an example of a conventional cooling device.
7 is an enlarged view of a main part of FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Shroud casing 11 Casing main body 12 Diffuser 30 Cooling fan 40 Drive device

Claims (2)

A cooling fan, a casing body arranged to extend upstream from the periphery of the cooling fan, and a downstream end of the casing body so as to protrude from the downstream end to the downstream side in the axial direction. A diffuser having an inner diameter that is larger than the outer diameter and that gradually increases in diameter toward the downstream side in the axial direction. The upstream side of the inner peripheral surface forms a convex surface, whereas the downstream side forms a concave surface and forms an S-shaped alphabet. A cooling device, comprising: a shroud casing including: a driving device that rotationally drives the cooling fan, wherein the cooling fan partially overlaps the diffuser. A shroud casing used in the cooling device according to claim 1, wherein the casing main body is arranged to extend upstream from the periphery of the cooling fan, and the axial direction from the downstream end to the downstream end of the casing main body A diffuser provided so as to protrude downstream, and the diffuser has an inner diameter that is larger than the outer diameter of the cooling fan and gradually expands toward the downstream side in the axial direction. The shroud casing is characterized in that the upstream side of the casing has a convex surface, whereas the downstream side has a concave surface to form an alphabet S-shape.

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