JPH09321458A - Waterproof chassis structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure the watertightness to the interior of a chassis and also to obtain simply a chassis structure, which is low in cost and has a good shelf stability, by a method wherein O-rings, which are respectively fitted into recessed grooves bored annularly in the sides of the bottoms of the heads of screws, are inserted in a case body from the interior of the case body. SOLUTION: Threaded holes are respectively provided spirally in the four corners of a radiating plate 8 and through holes 9 provided with each step by spot facing work are bored in four places located at positions, which oppose to these threaded holes, on one wall surface of a chassis 7. The plate 8 is fixed to the chassis 7 using screws 10. Recessed grooves are respectively formed in the bottom sides of the screw heads of the screws 10 and O-rings 12, which are sealing members, are respectively charged in these grooves. The threaded holes provided spirally in the plate 8 are made to coincide with the holes 9 bored in the chassis 7, the screws 10 are respectively inserted in the holes 9, the heads of the screws 10 are respectively made to fit into the step parts subjected to spot facing work and the screws 10 are clamped to the plate 8 to fix integrally the plate 8 with the chassis 7. Thereby, the interior of the chassis 7 is shut off from the outside encircling a radiating fin 15 by the interposition of the O-rings 12 between the screws 10 and the holes 9 and rainwater can be prevented from infiltrating into the interior of the chassis 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chassis structure, and more particularly to a chassis structure for electronic equipment that requires waterproofness.

[0002]

2. Description of the Related Art Among electric appliances, there are many opportunities to use them outdoors, and accordingly, when used in an environment exposed to rainwater, waterproofness inside the electric appliances is required. In many of those having a wiring board on which a heating element such as the above is mounted, a cooling plate is provided with a radiator plate (heat sink). Examples of the above-mentioned conventional technology are shown in FIGS. FIG. 4 is a perspective view showing an integrated structure of the chassis 1 and the heat dissipation plate 2 using a molding die. With this structure, the number of parts is small, but the shape of the heat sink is complicated, which increases the manufacturing cost of the molding die.
Replacing the heat sink is not easy. FIG. 5 is a perspective view showing a structure in which the separately processed heat dissipation plate 2 is attached to the chassis 1. In this case, in order to fix the heat sink 2 to the chassis 1, it is necessary to process the screw hole 3 in the chassis 1 and the through hole 4 in the heat sink 2.

When the screw hole 3 is penetrated through the chassis 1, it is necessary to take measures such as filling the screw hole 3 with a sealing material, which may increase the number of work steps and deteriorate the maintainability. It is not preferable to use the hole 3 as a through hole because there is a problem in reliability. On the other hand, in order to ensure watertightness inside the chassis, a required wall thickness t (FIG. 6) is required to make the screw holes of the chassis 1 blind holes, and as a result, miniaturization of the chassis 1 is limited. become. Further, when using the commercially available heat dissipation plate 2, there are many problems such that the through hole 4 needs to be separately processed for the mounting screw.

[0004]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention has an object to secure a watertightness to the inside of a chassis and to easily provide a chassis structure which is low in cost and good in maintenance. It is a thing.

[0005]

In order to achieve the above object, the screw holes and the through holes are aligned so that they are opposed to each other, and the screw holes are screwed into the radiator plate side, and the screw holes are inserted into the chassis side. A hole is bored, and the heat sink is fixed to the chassis by using a screw having a head inserted through the through hole. At this time, an O-ring is interposed between the bottom surface of the screw head and the chassis in contact with the chassis to fasten the through hole to form a watertight structure. A groove is engraved, an O-ring is fitted in the annular groove, and a through hole having a spot facing step corresponding to the diameter of the screw head is bored in the chassis.

That is, according to the present invention, as described in the claims, a housing having a mounting wall surface, and a heat dissipation plate having a heat dissipation fin which is in close contact with the outer surface of the housing and dissipates heat inside the housing. A through hole provided with a counterbore step from the inside of the wall surface of the housing, a screw hole screwed into the heat dissipation plate at a position facing the through hole, and a flat machine screw screwed into the screw hole. The flat small screw is formed by inserting a concave groove annularly formed on the bottom side of the head, an O-ring fitted into the concave groove, and the flat small screw fitted with the O-ring from the inside of the housing. The waterproof chassis structure is characterized in that the heat dissipation plate and the housing are fastened together. With the above configuration, it is possible to improve the heat conduction efficiency between the chassis and the interior parts by fastening the screws to fix the heat sink to the chassis.

[0007]

FIG. 1 shows an embodiment of the present invention.
~ It demonstrates with reference to FIG. In FIG. 1, reference numeral 7 is a box-shaped chassis, and 8 is a radiator plate provided with radiator fins 15.
Screw holes 13 are screwed at four corners of the heat dissipation plate 8, and through holes 9 having counterbored steps 9a are formed at four locations on one wall surface of the chassis 7 facing the screw holes 13. . The heat dissipation plate 8 is fixed to the chassis 7 with screws 10. The screws used in the present embodiment are preferably flat small screws according to the JIS standard, or hexagon socket head cap screws with a flat bottom surface of the screw head and a relatively thick head thickness. is there. Further, a concave groove 11 is formed on the bottom surface side of the screw head 10a of the screw 10, and the groove 11 is loaded with an O-ring 12 which is a seal member.

The screw hole 13 of the heat dissipation plate 8 and the through hole 9 of the chassis 7 are aligned with each other, a screw 10 is inserted into the through hole 9, and the head 10a of the screw 10 and the spot facing step 9a are fitted. The heat sink 8 is fixed integrally with the chassis 7 by fastening the screws 10. As a result, the interposition of the O-ring 12 shields the interior of the chassis 7 from the external environment surrounding the heat dissipation fins 15, and prevents the infiltration of rainwater. Further, since the wall surface of the chassis 7 and the heat dissipation plate 8 are tightly fastened together via the O-ring 12, for example, the heating element 1
Even a module case accommodating a wiring board for mounting 4 can easily release heat.

[0009]

By implementing the present invention, it is possible to secure a watertightness inside the chassis and to provide a chassis structure which is low in cost and good in maintainability, which reduces the number of parts and working steps and improves the production efficiency. The excellent effect of reducing the production cost can be obtained.

[Brief description of drawings]

FIG. 1 is a perspective view showing a mounting procedure according to an embodiment of the present invention.

FIG. 2 is an exploded view showing a cross section of the fastening portion in FIG.

FIG. 3 is a cross-sectional view showing a state in which fastening is completed in FIG.

FIG. 4 is a perspective view showing a conventional chassis with a heat dissipation plate.

FIG. 5 is a perspective view showing a procedure for attaching a heat sink to a conventional chassis.

6 is a partial cross-sectional view showing the fastening portion of FIG.

[Explanation of symbols]

 1, 7 ... Chassis 2, 8 ... Heat sink 3, 13 ... Screw hole 4, 9 ... Through hole 9a ... Counterbore processing step 5, 10 ... Screw 10a ... Screw head 10b ... Screw base 11 ... Recessed groove 12 ... O Ring 14 ... Heating element 15 ... Radiating fin t ... Wall thickness

Claims (1)

[Claims] 1. A housing having a mounting wall surface, a heat radiating plate having a heat radiating fin for radiating heat inside the housing by closely contacting the outer surface of the housing, and a spot facing step from the inside of the wall surface of the housing. Through hole, a screw hole screwed into the heat dissipation plate at a position facing the through hole, a flat machine screw screwed into the screw hole, and an annular hole formed on the bottom face side of the flat machine screw. A groove, an O-ring fitted in the groove, and the flat screw having the O-ring fitted thereinto are inserted from the inside of the housing to fasten the heat dissipation plate and the housing. Waterproof chassis structure that does.