JP3058713B2 - Cooling structure for small electronic device housing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling structure for a small electronic device housing which has a simple structure, has a dustproof effect, and can be efficiently cooled in a cabinet structure of an electronic device installed in an office environment. is there.

[0002]

2. Description of the Related Art As semiconductor devices become more highly integrated, the size of electronic devices is reduced, the heat generation density is increased, and an efficient cooling method is desired. The natural air cooling system is widely used for devices installed in offices and the like because it uses no power for cooling and has no noise.

FIG. 5 shows a typical example of a conventional electronic equipment cabinet placed in an office environment. (A) is an external view, and the upper part is a partly sectioned view so that the electronic device housed therein can be seen. (B) is an enlarged view of a main part of a unit (shelf) constituting the electronic device. In FIG. 5, 1 is a cabinet, 2 is a shelf, 3 is a shielding plate for preventing thermal interference between upper and lower units, and 4 is 1C
Are housed in the shelf 2 by a printed board on which components such as these are mounted.

[0004]

In a device or the like to be installed in an office, it is particularly preferable to use a small and thin cabinet. The upper surface of the cabinet has electronic devices on which documents and the like are placed and which is further housed in another cabinet. Is often required, and even if there is an exhaust port on the top surface, it is often blocked. Further, there is a possibility that a cup or the like containing coffee, tea or the like may be placed, so-called coffee protect (to prevent the coffee from flowing into the electronic device when the coffee spills) is required, and the upper surface is exhausted. No opening can be provided.

FIG. 6 shows the flow of natural air-cooled airflow in a conventional structural cabinet. The dotted line 11 indicates the flow of the airflow. The air sucked in from the front opening 10 of the cabinet absorbs heat of the electronic components in the shelf 2 and is exhausted from the opening 13 on the back surface through the shielding plate 3 (11-1).
Or through the space inside the shelf through the back of shelf 2,
Exhaust air to the outside of the cabinet from the exhaust port at the top front (11
-2).

On the other hand, there is a possibility that the openings on the side and back sides may be installed in close contact with the walls of the office. Therefore, it is not advisable to provide the intake and exhaust ports on the back and side surfaces on those surfaces. If the cabinet is installed with the wall in close contact with the back surface, the distance to the exhaust port will be long and the cooling capacity will be significantly reduced.

[0007] In an office environment, a lot of dust is generated due to ingress and egress on a foot, movement of a person, and the like. For this reason, since a precision electronic device does not like dust, a large opening cannot be provided. However, when the opening is small, the cooling performance is significantly reduced, and particularly in a natural air cooling device, the cooling performance is extremely lowered. As described above, the applicable range of the conventional small cabinet of the natural air cooling system is limited to the device having a low heat generation density.

[0008] In view of these drawbacks, an object of the present invention is to provide
An object of the present invention is to provide a cooling structure for a small-sized electronic device housing, which is provided with an opening required for intake and exhaust while efficiently preventing the dust from being taken into the cabinet.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a cabinet structure in which an electronic device is built, and has a structure in which at least one of the front and rear or left and right side surfaces is suctioned slightly below a vertically central portion. An extension duct which extends downward from the intake port to the outside of the cabinet and has an open port on the lower surface to form an intake vertical duct space of 20 cm or more , and an exhaust port is provided at the uppermost portion of the cabinet; It features a natural air cooling structure having an extension duct extending downward from the mouth to the outside of the cabinet and forming an exhaust vertical duct space of a predetermined length having an open mouth on a lower surface.

[0010]

According to the above-mentioned means, the present invention provides an intake duct structure having an intake port on the lower side so that the intake port for cooling air passes through a duct flow path from below to above and into the cabinet. On the contrary, the air has a duct structure with an exhaust port on the lower side to exhaust from the cabinet through the flow path from the upper side to the lower side and then to the outside of the cabinet,
Conventional cabinets differ greatly in that there is no duct structure that takes these factors into account.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows an external view of an embodiment of the present invention. In this figure, an intake duct 7 is provided on the front surface, and a box-shaped cover 8 is provided on the upper surface.

FIG. 2 is a cross-sectional view of a cabinet according to a first embodiment of the present invention. The air enters from below the intake duct 7, flows upward and downward through the vertical duct space 10 a, and enters the cabinet through the intake port 10. From here, the cooling air enters each shelf 2 and the absorbed air reaches the overhead space 12 via the shielding plate 3 and the back surface space, and further from there, the exhaust vertical formed by the side surface of the cabinet and the box-shaped cover 8. The air flows from the top to the bottom in the duct space 12a, and is exhausted to the outside of the cabinet through the exhaust port 14.

The airflow velocity of the natural air cooling in the vertical duct space 10a for intake air is at most about 20 cm / s. At such an airflow velocity, dust and the like are considered to be settling dust. Therefore, the dust that has soared at the speed of the surrounding airflow or the like flows into the vertical duct space 1.
It may be configured such that it falls on the floor surface on the way between 10 cm and 20 cm in length of 0a and is not taken into the cabinet. On the other hand, since the exhaust port has the exhaust vertical duct space 12a in addition to the flow of the exhaust air, dust and the like fall on the same principle, so that even if there is a little wind around the exhaust port, the exhaust port can be configured not to be taken into the cabinet.

The intake duct 7 has a length of, for example, 500 mm.
When the position of the intake port 10 is provided slightly below the vertical center of the cabinet 1, the cooling performance is improved. Further, if the length of the exhaust duct formed by the box-shaped cover 8 and the cabinet 1 from the upper surface of the box-shaped cover 8 to the exhaust port 14 is, for example, about 150 mm, it is hard to be affected by the outside air. In this case, the length from the upper surface of the cabinet 1 to the exhaust port 14 is, for example, about 100 mm.

FIG. 3 is a cross-sectional view of a cabinet according to a second embodiment of the present invention, and is a cross-sectional view of the cabinet when the back surface is closely attached to a wall. The structure is the same as that of the first embodiment except that there is no exhaust port on the back side. Therefore, it goes without saying that the same effect as in the first embodiment is obtained. The same cooling characteristics can be ensured by increasing the number of exhaust openings at other places such as the front side, by reducing the number of exhaust ports to the back side.

In the present embodiment, the example in which the air inlet is provided on the front surface has been described.
The same effect as described above can be obtained by providing a structure in which exhaust ports are provided on the left and right side surfaces, and in some cases, on the back surface, and extend therefrom to the lower side of the duct.

As described above, in the cooling structure for a small electronic device housing according to the present invention, since the vertical duct space is provided in the exhaust port, there is an advantage that the cooling performance is not deteriorated and a dustproof structure can be obtained. Further, since the opening area can be increased, the cooling performance can be improved. FIG. 4 is a characteristic diagram comparing the cooling performance of the cabinet of the present invention structure and the cabinet of the conventional structure. In this case, the calorific value per printed board of 28 cm × 20 cm is 8 W. In the figure, A shows the case where the back surface of the conventional cabinet is installed in close contact with the wall, B shows the case where the back surface can be exhausted with the conventional cabinet structure, and C shows the case where the cabinet has the structure of the first embodiment of the present invention. It is. A has a large temperature rise because there is no exhaust port on the back,
B that can be evacuated on the back side recovers about 20%. In this embodiment, the temperature is further reduced by 10%.

Further, the natural air cooling device is susceptible to the influence of the surrounding airflow, and the temperature may rise by about 50% particularly when the wind is directed toward the exhaust port of the cabinet. In the structure of the present invention, even if the air-conditioning airflow or the like hits the cabinet, since the exhaust port is located on the lower side, the structure is such that the wind does not directly hit the exhaust port. It has a structure that is strong against the environment.

[0019]

As described above, according to the present invention, an opening required for intake and exhaust is provided to prevent the dust from being taken into the cabinet, and a small electronic device housing for efficiently cooling the electronic device is provided. A cooling structure can be provided.

[Brief description of the drawings]

FIG. 1 is an external view showing an embodiment of the present invention.

FIG. 2 is a sectional view of the cabinet according to the first embodiment of the present invention.

FIG. 3 is a sectional view of a cabinet according to a second embodiment of the present invention.

FIG. 4 is a characteristic diagram comparing the cooling performances of the cabinet of the present invention structure and the cabinet of the conventional structure.

FIG. 5 is an external view showing a conventional electronic device cabinet.

FIG. 6 is a cross-sectional view illustrating a cooling structure of a conventional electronic device.

[Explanation of symbols]

1 ... cabinet, 2 ... shelf, 3 ... shielding plate, 4 ...
Printed board, 6: Cabinet foot, 7: Air intake duct, 8: Box-shaped top cover, 10: Front air inlet, 10a ...
Inlet vertical duct space, 11: air flow, 12: overhead space, 12a: exhaust vertical duct space, 13: rear exhaust port, 14: duct exhaust port.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H05K 7/20

Claims (1)

(57) [Claims] In a cabinet structure having a built-in electronic device, an intake port is provided slightly below a vertically central portion of at least one of the front and rear or left and right side surfaces, and extends downward from the intake port to outside the cabinet. It has an extension duct that forms an intake vertical duct space of 20 cm or more with an open port on the side, an exhaust port is provided at the top of the cabinet, extends downward from the exhaust port outside the cabinet, and has an open port on the lower surface. A cooling structure for a small electronic housing, characterized by a natural air cooling structure having an extension duct forming an exhaust vertical duct space of a predetermined length.