JPH0225261Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a sheet metal outer casing for audio equipment for housing heat-generating parts such as transformers, and is particularly suitable for application to cases and covers of electronic equipment such as audio power amplifiers. It is something.

In recent years, audio equipment such as amplifiers and tuners have become increasingly smaller and thinner. In particular, power amplifiers and the like must achieve this reduction in size and thickness while increasing their output. However, from the standpoint of safety, for example, safety standards stipulate the temperature rise of the outer casing of power amplifiers, etc., such as cases and covers. This requires an outer casing with better heat dissipation characteristics than conventional ones. Such an outer casing usually has a large number of holes for heat radiation near the heat generating components, and in order to improve the heat radiation characteristics, the aperture ratio of the heat radiation holes can be increased. Also, from the viewpoint of safety, for example, the upper limit of the size of the opening is stipulated by safety standards.

As a conventional outer casing of this type, one in which both sides of an iron plate formed into a predetermined shape are directly painted is generally widely used because it is inexpensive and has high mechanical strength. However, the outer casing having such a configuration has poor heat dissipation characteristics, and for this reason, it has been difficult to achieve miniaturization and thinning. On the other hand, outer casings made of a copper plate or aluminum plate coated on one side are known as external casings with excellent heat dissipation properties, but such configurations have the drawbacks of high cost and low mechanical strength. Ta. Furthermore, the outer casing, which is made of a plastic plate with one side painted, has excellent heat sensitivity and does not feel that hot when you touch it with your fingers, but the mold cost during manufacturing is high and the shielding effect is low. It had the disadvantage of being weak.

The present invention was devised in view of these problems, and aims to provide an outer casing that is as simple as possible and has good heat dissipation characteristics.

Hereinafter, an embodiment in which the present invention is applied to a cover of an audio power amplifier will be described with reference to the drawings.

As shown in FIGS. 1 to 3, the cover 1 according to the present embodiment is constructed by bending and forming a steel plate 2 into a substantially U-shaped cross section. It is adapted to be screwed to a chassis (not shown) through the hole 5. A large number of elongated heat radiation holes 7 are provided in the top plate portion 6 of the cover 1 at locations close to heat generating components such as a transformer attached to the chassis.

As clearly shown in FIG. 3, on the surface of the steel plate 2,
A plating layer 8 of copper, aluminum, etc. is formed. In addition, since the plating layer 8 has good thermal conductivity, it can effectively disperse heat, thereby effectively preventing the cover 1 from being partially overheated. Further, the plating layer 8 is formed on the steel plate 2
Since it functions as a buffer between the steel material 2 and the coating 9, even if the steel material 2 is bent after being coated with the coating 9, the coating 9 will hardly be cracked. The thickness of this plating layer 8 is preferably about 5μ in the case of copper and about 50μ in the case of aluminum. Furthermore, cover 1
A coating 9 with a thickness of about 15 μm made of a heat-resistant paint having heat insulating properties is applied to the entire outer surface and the inner surface near the heat dissipation holes 7 A (indicated by broken lines in FIGS. 1 and 2, respectively). It has been subjected. Note that if the coating 9 is not applied, the surface of the cover 1 (i.e.,
When you touch the plating layer 8) with your finger, the heat conductivity of the plating layer 8 is good, so even the surrounding temperature is transferred to your finger, making it feel relatively hot. This is because the coating 9 has heat insulating properties (in other words, the thermal conductivity is not very good).
Since only the temperature of the part you touch is transferred to your fingers, it doesn't feel that hot, so you can get a cover with excellent heat sensitivity. Also, a portion A of the inner surface of the cover 1 near the heat radiation hole 7, which is relatively easily overheated.
is coated with a heat-resistant paint 9 that has heat insulating properties (in other words, does not have very good thermal conductivity). The radiant heat is effectively radiated to the outside through the heat radiation holes 7, and therefore, overheating of the neighboring portion A due to the radiant heat can be prevented. Furthermore, oxidation and corrosion in the vicinity A, which is relatively prone to overheating, can be effectively prevented by the coating 9. In particular, since a heat-resistant paint is used as the coating 9,
There is almost no change over time. As this heat-resistant paint, a polyester paint which has been widely used in the past can be used alone, or an epoxy resin can be used as an undercoat. In addition, in the configuration of this example, the plating layer 8 acts as a buffer material, so
It is also possible to use an acrylic paint that is relatively difficult to stretch as the heat-resistant paint.

As described above, in this embodiment, heat dispersion is achieved by forming a plating layer 8 such as a copper plating layer or an aluminum plating layer with high thermal conductivity on the surface of the steel plate 2 constituting the cover 1. In addition to aiming for gender,
By applying a coating 9 to a portion A near the heat radiation hole 7 on the inner surface of the cover 1, which receives radiation from heat-generating components, overheating of this portion A is prevented. Therefore, in the cover 1 according to this embodiment, the temperature rise can be lowered by about 3° C. compared to a conventional cover in which both sides of a steel plate are directly coated. Further, when copper plating is applied, there is an advantage that the presence of the copper plating layer 8 provides a greater shielding effect than a conventional cover made of steel plate.

The cover 1 as in this embodiment can be manufactured, for example, as follows.

First, a plated layer 8 is formed on the surface of a flat steel plate 2, and then punched and pressed into a predetermined shape. Next, holes such as the heat dissipation hole 7 are formed, and the side plate parts 3 and 4 are bent slightly by bending press. Next, in this state, a predetermined coating 9 is applied to both sides of the steel plate 2. At this time, as shown in Figure 3,
Coating 9 is also applied to the inner peripheral surface 10 from both sides of the heat radiation hole 7.
This also prevents oxidation and corrosion of the inner circumferential surface 10. Then, the cover 1 is transported in this state to an assembly factory or the like, and then the side plate portions 3 and 4 are bent using a bending press into the final shape shown in FIGS. 1 to 3.

In this way, the cover 1 can be transported or stored in a non-bulky state without being bent into the final shape, so that transportation costs and storage costs can be greatly reduced. Moreover, in this case, in this embodiment, since the plating layer 8 is provided between the steel plate 2 and the coating 9, this plating layer 8 acts as a buffer against elongation during bending, and The adhesion between the plating layer 8 and the coating 9 effectively prevents the coating 9 from cracking during bending. Therefore, as described above, it is possible to apply the coating 9 before bending the cover 1 into its final shape, and to bend the cover 1 immediately before attaching it to a chassis or the like.

In the above embodiment, a coating 9 is applied to the entire outer surface of the cover 1, thereby protecting the plating layer 8 and improving the heat sensitivity of the outer surface of the cover 1. . On the other hand, cover 1
It is sufficient to apply coating 9 only to the area near the heat dissipation hole 7 on the inner surface of the housing, which is convenient for grounding in this case, but of course, coating 9 must be applied to the entire inner surface. Good too. Also, steel plate 2
If the plating layer 8 is formed after the holes are formed, the plating layer 8 can be formed on the inner circumferential surface 10 of the heat dissipation hole 7.

As explained above, in the present invention, a plating layer with good thermal conductivity is formed on the surface of the metal plate constituting the sheet metal outer casing for audio equipment, and the entire outer surface of the metal plate and The inner surface of the metal plate at least in the vicinity of the heat dissipation hole is coated with a heat-resistant paint having heat insulating properties through the plating layer. Therefore, the coating applied to the inner surface of the metal plate reduces the amount of radiant heat transmitted from the heat generating parts to the metal plate, and the plating layer on the surface of the metal plate effectively achieves heat dispersion. Temperature rise in the outer casing is reduced. Therefore, the distance between the inner surface of the metal plate and the heat generating component can be reduced, and the entire device can be made smaller and thinner. Further, even when the size of the heat dissipation hole is relatively small, it is possible to effectively suppress a rise in temperature of the outer casing. Furthermore, when painting the outer surface of the outer casing, it is very easy to paint both sides of the outer casing in one step. Furthermore, in this case, since the plating layer between the metal plate and the paint functions as a buffer material, it becomes possible to bend the metal plate after painting.

[Brief explanation of the drawing]

1 is a perspective view of a cover according to an embodiment of the present invention, FIG. 2 is a plan view of the same, and FIG. 3 is a partial sectional view taken along the line - in FIG. 2. In addition, in the symbols used in the drawings, 2...steel plate,
7... Heat radiation hole, 8... Plating layer, 9... Painting,
It is.

Claims (1)

[Scope of Claim for Utility Model Registration] In a sheet metal outer casing for housing heat-generating components having heat dissipation holes, a plating layer with good thermal conductivity is provided on the surface of the metal plate constituting the sheet metal outer casing. Further, the entire outer surface of the metal plate and the inner surface of the metal plate in at least a portion near the heat dissipation hole are coated with a heat-resistant paint having heat insulating properties through the plating layer. Sheet metal outer casing for audio equipment.