JPH0832279A - Housing structure for electronic apparatus - Google Patents

Abstract

PURPOSE:To prevent the electromagnetic wave from entering into a housing through an air intake port or an air discharge port without sacrifice of heat dissipation capacity. CONSTITUTION:A shield member 35 is interposed between the lower surface 29 at a housing section 21 and a convection introduction plate 30 in order to prevent the electromagnetic wave from intruding through an air intake port 27a into the housing section 21 or being discharged. Furthermore, a shield member 36 is interposed between the upper surface 31 at the housing section 21 and a convection introduction plate 33 in order to prevent the electromagnetic wave from intruding through an air discharge port 28 into the housing section 21 or being discharged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a casing of an electronic device which is constructed so as to cool the inside of a casing for accommodating an electronic circuit package by natural convection of air and to protect the inside of the casing from electromagnetic waves. Regarding body structure.

[0002]

2. Description of the Related Art FIGS. 5 to 8 show a conventional housing structure of this type.

As shown in FIG. 5, this casing is constructed by arranging a plurality of casing parts 1 in the vertical direction. Each mother board 2 provided in each casing part 1 has a package. The electronic circuit package 5 is connected via the connector 3 and the motherboard connector 4.

A ventilation panel 7 having a plurality of air intakes 7a is attached to the lower front surface of the casing 1, and an air discharge port 8 is provided on the upper rear surface of the casing 1. Has been. The air intake 7 is provided below the housing 1.
A convection guide plate 10 that guides the air taken in from the a toward the opening 9a formed in the lower surface 9 of the casing 1 is provided, and the convection guide plate 10 is provided above the casing 1 and passes through the inside of the casing 1. A convection guide plate 13 that guides the air discharged from the opening 11a formed in the upper surface 11 of the casing 1 toward the air discharge port 8.
Is provided.

Therefore, as shown in FIG. 6, the cold outside air taken in from the lower side surface of the casing 1 rises by natural convection in the casing 1 to cool and warm the electronic circuit package 5. The air is discharged from the upper side surface of the casing 1.

Further, in this case, the whole case is made of a conductive material in order to protect the electronic circuit package 5 from electromagnetic interference. Further, a shield material 15 is provided at the air intake 7a so that electromagnetic waves do not enter from the air intake 7a, and similarly, a shield material 16 is provided at the air outlet 8.

According to this conventional casing structure, if the shield meshes of the shield members 15 and 16 provided on the air intake 7a and the air discharge port 8 are made fine in order to enhance the shield effect, the air intake port 7a and the air discharge port are formed. Since the ventilation area of No. 8 is reduced, there is a problem that the heat dissipation ability due to natural convection of air is reduced, and conversely, when the heat dissipation is emphasized, the mesh of the shield mesh becomes rough and the shieldability is deteriorated. It was

This will be explained using the ventilation panel 7 as an example. As shown in FIG. 7, the ventilation panel 7 is provided with n air inlets 7a having a vertical width h and a horizontal width w. The ventilation area A is w × h × n. However,
Since the shield material 15 is provided at these air intakes 7a, only the area occupied by the members of the shield material 15 is
The ventilation area will decrease. That is, when the opening ratio of the shield material (sum of area s of holes of the shield material / area of the entire shield material) is α, the actual ventilation area is A × α.
Therefore, if α is made small, the shielding effect becomes good, but the heat radiation ability is lowered, and if α is made large, the heat radiation ability is not so much lowered but the shielding effect is lowered.

[0009]

As described above, in the conventional housing structure, there is a problem that the heat dissipation ability is reduced when the shield effect is increased, and the shield effect is reduced when the heat dissipation ability is maintained to some extent. It was

The present invention has been made to solve the above-mentioned conventional drawbacks, and does not decrease the heat radiation ability.
An object of the present invention is to provide a housing structure of an electronic device that can enhance the shield effect.

[0011]

According to the present invention, there is provided a housing portion for accommodating an electronic circuit package and having openings on both upper and lower surfaces, and an air inlet provided below the housing portion and extending along the lower surface. A first convection guide plate that guides the air taken in in the direction toward the opening on the lower surface, and the air discharged from the opening on the upper surface that is provided above the housing portion and passes through the inside of the housing portion. In a housing structure of an electronic device having a second convection guide plate which is guided in a direction along an upper surface and is discharged from an air outlet, the lower surface of the housing portion and the first convection guide plate are provided with the above-mentioned structure. A first shield member is provided to prevent an electromagnetic wave entering from the air intake from entering the inside of the housing or an electromagnetic wave emitted from the inside of the housing, and is provided on the upper surface of the housing and the second shield member. The air between the convection guide plate Second shield material has a configuration that is provided to block electromagnetic waves electromagnetic waves entering from the outlet is released from or housing interior to prevent the entering the housing portion.

[0012]

In the present invention, since the first shield material is provided between the lower surface of the casing and the first convection guide plate,
The attachment area of the shield material can be made larger than the area of the air intake. Similarly, since the second shield material is provided between the upper surface of the housing and the second convection guide plate, the mounting area of the second shield material should be larger than the area of the air discharge port. You can

Therefore, assuming that the area of the air intake is A1, the mounting area of the first shield material is B1, and the opening ratio of the first shield material is α1, α1 is determined within the range of A1 ≦ B1 × α1. As a result, the first shield member can be attached without impairing the intake capacity.

Similarly, assuming that the area of the air discharge port is A2, the mounting area of the second shield material is B2, and the aperture ratio of the second shield material is α2, α2 is determined within the range of A2 ≦ B2 × α2. By doing so, the second shield material can be attached without impairing the exhaust capacity.

[0015]

Embodiments of the present invention will be described in detail below with reference to FIGS.

FIGS. 1 to 3 are views for explaining the first embodiment, and FIG. 2 is a partially cutaway perspective view of a housing of an electronic device.
2 is a sectional view taken along the line AA of FIG. 2, and FIG. 3 is an explanatory view showing the relationship between the cross section of the ventilation passage and the shield material.

The case according to the present invention is constructed by arranging a plurality of case parts 21 in the vertical direction, as in the conventional example.
As shown in FIGS. 1 and 2, the package connectors 23 are provided on the motherboards 22 provided in the respective housings 21.
An electronic circuit package 25 is connected via the motherboard connector 24.

A ventilation panel 27 is attached to the lower front surface of the casing 21, and a plurality of air intake ports 27a are formed in the ventilation panel 27. An air outlet 28 is provided on the upper rear surface of the casing 21. The air intake 27 is provided below the housing 21.
A convection guide plate 3 that guides the air taken in from a toward the opening 29a formed in the lower surface 29 of the housing 21.
0 is provided above the housing portion 21, and the air that passes through the inside of the housing portion 21 and is discharged from the opening 31a formed in the upper surface 31 of the housing portion 21 is guided toward the air discharge port 28. A convection guide plate 33 is provided.

Therefore, as shown in FIG. 1, the cold outside air taken in from the air intake 27a on the lower side surface of the housing portion 21 rises by natural convection in the housing portion 21 to cool the electronic circuit package 25. However, the warmed air is stored in the housing 21.
Is discharged from the air discharge port 28 on the upper side surface of the. The case of this example has the same dimensions as the case of the conventional example, the total area of the air intake 27a is the same as the total area of the conventional air intake 7a, and the total area of the air discharge port 28 is the same. Has the same size as the total area of the conventional air outlet 8. Further, the total area of the air intake 27a and the air exhaust port 28 is the same, and the air taken in from the air intake port 27a is exhausted from the air exhaust port 28 without delay after passing through the inside of the housing portion 21. To be done.

On the other hand, in order to protect the electronic circuit package 25 from electromagnetic interference and not to interfere with others, it is necessary to prevent the emission of electromagnetic waves, and the entire housing is made of a conductive material.

Further, in order to prevent the electromagnetic waves entering from the air intake 27a from entering the housing portion 21 or blocking the electromagnetic waves emitted from the inside of the housing portion 21, a shield mesh is formed below the housing portion 21. A shield material 35 is provided. This shield material 35 is used for the air intake 27a.
The air taken in from the inside is provided between the lower surface 29 of the casing 21 and the convection guide plate 30 which is a ventilation passage to reach the inside of the casing 21, and in this example, among the ventilation passages. The shield material 35 is provided so as to be close to the lower surface 29 having the largest cross-sectional area.

Further, in order to prevent the electromagnetic waves entering from the air outlet 28 from entering the housing 21 or blocking the electromagnetic waves emitted from the inside of the housing 21, a shield mesh is formed above the housing 21. A shield material 36 is provided. The shield material 36 is provided between the housing upper surface 31 and the convection guide plate 33, which is a ventilation passage until the air discharged from the housing upper surface 31 is discharged from the air outlet 28. In this example, the shield material 36 is provided so as to be close to the upper surface 31, which is the largest cross-sectional area of the ventilation passage.

In this example, the ventilation panel 27 and the shield material 35 (36) are made into a case-shaped convection guide plate 30 (3).
It is attached to 3) and is unitized, and this unit can be attached to both the upper and lower sides of the casing 21.

Next, the operation of the above-mentioned housing structure will be described taking the shield material 35 side as an example.

As described above, the shield material 35 is closely attached to the lower surface, which is the largest cross-sectional area of the air flow passage, and as shown in FIG. 3, the total area B of the shield material 35 is B. Is the total area A (w × h of the air intake 27a
Xn) is made sufficiently larger. Therefore, A ≦ B ×
If the aperture ratio α is selected within the range of α (α; sum of the holes s of the shield material 35 / B), the shield material 35 can be attached without impairing the intake capacity of the air intake 27a. Similarly, the shield material 36 can also be attached to the housing portion 21 without hindering the exhaust capability of the air outlet 28.

On the other hand, the heat radiation effect of natural convection of air is
It is determined by the areas of the air intake port 27a and the air exhaust port 28. Therefore, by selecting the minimum α in the range described above, it is possible to improve the shielding property without lowering the heat dissipation effect.

FIG. 4 is a diagram for explaining the second embodiment of the present invention. In this example, the shield material 35 is slightly inclined with respect to the lower surface 29 of the housing portion 21. Shield material 3
Even if 5 is provided in such an inclined manner, the shielding property can be improved without lowering the heat dissipation effect as long as A ≦ B × α is satisfied. The same applies to the shield material 36.

[0028]

As described above, in the housing structure for electronic equipment of the present invention, the first shield member is attached to the ventilation passage portion having a cross section larger than the area of the air intake port, and the air exhaust port is provided. Since the second shield material is attached to the portion of the ventilation passage having a cross section larger than the area of, the shielding performance can be improved without lowering the heat dissipation effect.

[Brief description of drawings]

FIG. 1 is a sectional view of a housing according to a first embodiment of the present invention.

FIG. 2 is a partially cutaway perspective view of the housing.

FIG. 3 is a diagram illustrating an operation of the casing.

FIG. 4 is a sectional view of a housing according to a second embodiment of the present invention.

FIG. 5 is a partially cutaway perspective view of a conventional housing.

6 is a cross-sectional view taken along the line BB of FIG.

FIG. 7 is a perspective view of a ventilation panel of the housing.

8 is an enlarged view of circle D in FIG.

[Explanation of symbols]

21 housing part 25 electronic circuit package 27a air intake port 28 air discharge port 29 lower surface 30 first convection guide plate 31 upper surface 33 second convection guide plate 35 first shield material 36 second shield material

Claims (1)

[Claims] 1. A housing portion for accommodating an electronic circuit package and having openings formed on both upper and lower surfaces, and air introduced below the housing portion from an air inlet in a direction along the lower surface. A first convection guide plate that guides the air in a direction toward the opening of the housing, and air that is provided above the housing and passes through the inside of the housing and is discharged from the opening of the upper surface in a direction along the upper surface. In a housing structure of an electronic device having a second convection guide plate to be discharged from the discharge port, an electromagnetic wave entering from the air intake port is present between the lower surface of the housing section and the first convection guide plate. A first shield member is provided to prevent entry into the casing or electromagnetic waves emitted from the inside of the casing, and a first shield member is provided between the upper surface of the casing and the second convection guide plate. Electromagnetic waves entering from the air outlet are Second for preventing the electromagnetic waves emitted from the inside of the casing from being prevented from entering the casing part
A casing structure for electronic equipment, characterized in that the shield material is provided.