JPH11251771A - Small axial fan with heat sink - Google Patents

Abstract

PROBLEM TO BE SOLVED: To embody a small axial fan with a heat sink, wherein the effective cooling function for the vicinity of the center as well as the cooling effect at the rim of the axial fan due to a fin group disposed at a blast passage can be expected. SOLUTION: A small axial fan 1 with a heat sink is provided with a first fin group 2-1 disposed at a blast passage 4 of the small axial fan 1 and a second fin group 2-2, so as to oppose the top of a tubular hub 1-2 holding the blades of the axial fan 1. The second fin group 2-2 preferably has fins at the rim of a base 2-3 smaller than the outer diameter of the tubular hub 1-2 to form a second blast passage 4-2 so as to be connected or adjacent to a first blast passage 4-1 which the above mentioned first fin group forms, and a draft guide member is also provided together at the sides adjacent to the above mentioned first fin group 2-1 and the second fin group 2-2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an axial fan, and more particularly to a small axial fan with a heat sink.

[0002]

2. Description of the Related Art The demand for small axial flow fans with heat sinks is rapidly increasing for cooling of central processing units (CPUs), which are becoming particularly small and heat capacity shortages are becoming apparent. Downsizing and weight reduction are progressing along with maintenance.

[0003] These miniaturized and lightweight configurations are disclosed in Japanese Unexamined Patent Publication No.
There are many known examples such as Japanese Patent Application Laid-Open No. 111302 and Japanese Patent Application Laid-Open No. Hei 7-212829, and it goes without saying that heat is dissipated by blowing air from the axial fan to the surface of the multifaceted fin of the heat sink. Even in the combination of the fan and the heat sink, as shown in FIG. 6, in the conventional configuration in which the heat sink 2-1 is provided corresponding to the outer peripheral edge of the impeller 1-3 of the fan, the driving motor for the axial fan 1 is provided. Since 1-1 is located at the center of the axial fan 1, the electronic component (not shown) disposed at a portion facing the cylindrical hub 1-2 blocks the ventilation passage through which the cooling air passes. In addition, since no heat radiation fins are provided in the portion, cooling of the electronic components (not shown) in the portion cannot be expected. That is, as shown in the example of FIG. 6, in the configuration in which the fin group 2-1 of the heat sink is provided in the air passage 4 outside the impeller 1-3, the electrons arranged in the portion opposed to the fin group 2-1. Although parts and the like are efficiently dissipated, it is inevitable that heat dissipation near the opposing surface of the cylindrical hub 1-2 containing the drive motor 1-1 will be worse than that of the peripheral portion.

[0004]

The conventional structure as described above has a problem that the cooling effect at the center of the fan of the heat sink disposed in contact with the axial fan is not sufficient at the peripheral portion. Improvement was desired.

[0005]

SUMMARY OF THE INVENTION A small axial fan with a heat sink according to the present invention has a cylindrical shape for holding a blade of the axial fan together with a first fin group provided in a ventilation passage of the axial fan. A second fin group is provided in close proximity to the top of the hub, and the second fin group is preferably provided with fins implanted on an outer peripheral surface of a base portion smaller than the outer diameter of the cylindrical hub, so that a second air supply is performed. A passage is formed, and is arranged so as to be in communication with or close to a first air passage formed by the first fin group, and a ventilation guide is provided on a side surface close to the first fin group and the second fin group. The members are configured to be provided side by side.

[0006]

FIG. 1 is a sectional view of an example of a small axial flow fan with a heat sink according to the present invention. FIG. 2 is an axial flow fan 1 of the example, and FIG. 3 is a corresponding heat sink 2 of the example. It is a perspective view. As shown in the figure, the axial flow fan 1 is provided with an impeller 1-3 rotatably held by a drive motor 1-1 through a small air gap on an inner peripheral surface of a wind tunnel portion of a venturi case 1-4. A mounting plate 1-5 is fixed to the venturi case 1-4, and the mounting plate 1-5 is fixed together with an axial fan to an upper portion of the heat sink 2 with a ventilation passage 4 therebetween. The member to be cooled is disposed in contact with the member, and heat is dissipated through the heat sink 2 by the ventilation in the axial fan 1.

In this example, as in the prior art, a first pair of fins 2-1 arranged in a front-rear pair and arranged in the air passage 4 of the axial fan 1 forms a first air passage 4-1 and air As shown in FIGS. 1 and 3, the axial flow fan 1 is arranged between the pair of parallel first fin groups 2-1 as shown in FIGS. A second fin group 2-2 is also provided at a central portion facing the cylindrical hub 1-2 having the driving motor 1-1 therein, and forms a second Western-style passage 4-2.

[0008] The second fin group 2-2 preferably comprises
Fins are implanted on the outer peripheral surface of the base 2-3 smaller than the outer diameter of the cylindrical hub 1-2 of the axial fan 1. Although the base 2-3 is shown as an example of a cylinder in FIG. 3, an arbitrary shape can be set in consideration of not protruding greatly from the outer peripheral surface of the cylindrical hub 1-2.

FIG. 4 is a sectional view of a second embodiment of a small axial flow fan with a heat sink according to the present invention, and FIG. 5 is a perspective view of the heat sink 2. In addition to the configuration of the above-described first example, the first and second fin groups 2-1 and 2-2 are provided on a side surface close to the first fin group 2-1 and the second fin group 2-2.
A guide member 3 for guiding the ventilation so that the flow of air to the air does not scatter is additionally provided.

The guide member 3 regulates the flow of air by the axial fan 1 in order to enhance the cooling effect of the first fin group 2-1 and the second fin group 2-2.

Although not shown in detail and not shown,
It is also effective that the fin group 2-2 of the fin group 2-2 has a shape extending from the outer peripheral surface to the base portion 2-3, and the root of each fin is formed in an arc shape so that the flow of air is smooth. Regarding the fin group 2-2, the number, direction, and shape of the fins can be appropriately determined.

[0012]

The small axial flow fan with the heat sink according to the present invention has the cooling effect of the first fin group located in the air blowing passage in a normal state, and the second fin group has a portion near the cylindrical hub facing surface. There is an operational effect that can also achieve the cooling effect.

[Brief description of the drawings]

FIG. 1 is a sectional view of a first example of a small axial fan with a heat sink according to the present invention.

FIG. 2 is a perspective view of the axial fan of the example of FIG. 1;

FIG. 3 is a perspective view of the heat sink of the example of FIG. 1;

FIG. 4 is a sectional view of a second example of a small axial fan with a heat sink according to the present invention.

FIG. 5 is a perspective view of the heat sink of the example of FIG.

FIG. 6 is a cross-sectional view of an example of a small axial fan with a heat sink according to the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Axial fan 1-1 Drive motor 1-2 Cylindrical hub 1-3 Impeller 1-4 Venturi case 1.5 Axial fan mounting plate 2 Heat sink 2-1 First fin group 2-2 Second Fin group 2-3 base 3 guide member 4 air passage 4-1 first air passage 4-2 second air passage

Claims (4)

[Claims] 1. A small axial flow fan with a heat sink which is directly attached for heat dissipation of heat-generating electronic components, holding an impeller of the axial flow fan together with a first fin group provided in a ventilation passage of the axial flow fan. A second fin group disposed close to the top of the cylindrical hub. 2. A second fin group disposed close to the top of a cylindrical hub holding an impeller of an axial fan, the second fin group being symmetrical with the operating axis of the axial fan, and having a second air passage formed by the second fan. 2. The small axial flow fan with a heat sink according to claim 1, wherein the fan is formed so as to communicate with or approach a first air passage forming one fin group. 3. 3. The second fin group according to claim 1, wherein a fin is formed on an outer peripheral surface of a base portion smaller than an outer diameter of a cylindrical hub of the axial flow fan. Small axial fan with heat sink. 4. A small axial flow with a heat sink according to claim 1, wherein a ventilation guide member is provided on a side surface close to said first fin group and said second fin group. Juan.