JP6866590B2 - Electronic device housing - Google Patents

Description

The present invention relates to a housing of an electronic device, and more particularly to a waterproof structure of a housing of an electronic device installed outdoors.

In electronic devices exposed to outdoor rainwater, a sealed housing is generally adopted for the purpose of waterproofing the electronic circuits.

For example, Patent Document 1 describes a structure in which the heat radiating fins are sealed with a sealing plastic by an insert molding method and integrally molded with the housing so that a part of the heat radiating fins is exposed from a part of the housing. Has been done.

Japanese Unexamined Patent Publication No. 9-18176

In the housing of the conventional electronic device described in Patent Document 1, as shown in FIG. 9, a circuit board on which an electronic component as a heating element is mounted is connected to a heat radiation fin such as an aluminum alloy via a heat radiation sheet. A hole is made in the housing so that a part of the heat radiating fin is exposed, and the housing structure is integrated with a sealing plastic. However, in such a housing structure, a gap may be generated between the housing and the contact surface between the heat radiation fins, so that sufficient airtightness cannot be ensured due to flooding and the like, and the housing of the electronic device to be installed outdoors. There was a problem that it was not suitable for.

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to provide a housing of an electronic device capable of improving waterproofness while maintaining heat dissipation performance.

The housing of the present invention is a housing of an electronic device that houses a substrate assembly including a substrate that carries an electronic circuit.
The wall portion that supports the substrate and
It has a heat sink that extends within the wall and has a higher thermal conductivity than the wall.
A part of the heat radiating plate projects from the wall portion to the external space of the housing.

According to the housing of the electronic device of the present invention, the heat of the electronic circuit is efficiently transferred by the heat radiating plate sandwiched between the double wall structure of the outer wall and the inner wall, that is, the heat collecting portion and the heat radiating protruding portion exposed to the outside. It can be transmitted to the outside of the housing, and both heat dissipation performance and waterproof performance can be achieved.

FIG. 5 is a perspective view seen from the lid side showing the appearance of the housing of the electronic device according to the first embodiment of the present invention. FIG. 5 is a schematic cross-sectional view showing a housing of an electronic device in line xx of FIG. It is schematic cross-sectional view explaining the manufacturing process of the housing of the electronic device of Example 1. It is schematic cross-sectional view explaining the manufacturing process of the housing of the electronic device of Example 1. It is schematic cross-sectional view explaining the manufacturing process of the housing of the electronic device of Example 1. It is schematic cross-sectional view explaining operation of the housing of the electronic device of Example 1. FIG. It is the schematic sectional drawing of the housing of the electronic device which is Example 2 by this invention. It is the schematic sectional drawing of the housing of the electronic device which is Example 3 by this invention. It is schematic cross-sectional view which shows the housing of the conventional electronic device.

Hereinafter, the housing of the electronic device for outdoor installation according to the embodiment of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the following examples. In the examples, components having substantially the same function and configuration are designated by the same reference numerals, so that duplicate description will be omitted.

As shown in FIGS. 1 and 2, the housing 10 of the electronic device of the embodiment has a substantially rectangular parallelepiped shape. The housing 10 is composed of a tubular housing body 11 and a tubular lid 12 that are fitted to each other at each opening. The housing body 11 and the lid 12 have flanges 12F and 11F that project outward from the side walls of the open end faces and are surface-joined to each other. By surface-joining the flanges 11F of the housing body 11 and the lid 12 and the flange side surfaces of the 12F, a sealed storage space for accommodating electronic components or devices inside the housing body 11 and the lid 12 SP is defined.

The housing body 11 and the lid 12 are fixed to each other by being fastened with screws Sc or the like provided on the respective flanges in a state where the flanges 12F and 11F of the opening end faces are face-joined. A packing (not shown) may be sandwiched between the flanges 12F and 11F. By removing the lid 12 from the housing 10, the inside of the housing can be accessed.

The housing body 11 is a substantially rectangular parallelepiped tubular body that is closed at the other end (rear surface 13) facing the open end surface. The housing body 11 has a metal heat sink 14 that is insert-molded in the wall portion of the back surface 13. The heat radiating plate 14 includes a heat collecting portion 14A embedded in the housing body 11 and a heat radiating protruding portion 14B that is integrated with the heat collecting portion and is exposed.

The housing 10 is fixed to an outdoor structural portion such as an outer wall P by a mounting bracket 15 fastened with screws Sc or the like via a heat collecting portion 14A and a heat radiating protruding portion 14B.

A thermoplastic synthetic resin called general-purpose plastic is used as the material of the housing 10. General-purpose plastics include polyethylene (PE), polypropylene (PP), polyvinylidene chloride (PVC), polyvinylidene chloride (PVDC), polystyrene (PS), polyurethane (PUR), acrylonitrile butadiene styrene resin (ABS), and acrylonitrile styrene resin. (AS), acrylic resin (PMMA), polyvinylidene (PC) and the like. Further, engineering plastic can also be used for the housing 10. The heat radiating plate 14 having a higher thermal conductivity than the housing 10 is mainly made of aluminum alloy, stainless steel, or the like.

As shown in FIG. 2, the heat collecting portion 14A is sandwiched and embedded between the inner wall portion 11A of the back surface 13 and the outer wall portion 11B facing the outer space of the housing. The heat radiating protrusion 14B penetrates the outer wall portion 11B from the heat collecting portion 14A and is exposed to the external space. The heat radiating plate 14 is integrated with the housing body 11 so that only the heat radiating protrusion 14B portion is exposed. The heat radiating protrusion 14B enables heat radiating to the outside air. Further waterproofing effect can be achieved by providing the embankment portion 11C protruding from the outer wall portion 11B around the root of the heat radiation protruding portion 14B of the outer wall portion 11B.

The substrate (board assembly) of the electronic circuit 18 on which the electronic component 17 as a heating element is mounted via the heat conductive sheet 16 directly stretched on the fixed portion of the inner wall portion 11A is fixed by screws or the like (not shown). It is fixed by the load. The heat conductive sheet 16 is made of a metal such as copper or aluminum or ceramics.

As shown in FIG. 2, the mounting of the entire housing is performed by tightening a screw Sc or the like through a heat-dissipating protrusion 14B to be joined and a penetrating mounting hole 19 provided on the side surface of the mounting bracket 15. The mounting bracket 15 is fixed to the outer wall P in advance.

The manufacturing process of the housing will be described with reference to FIGS. 3 to 5.

As shown in FIG. 3, in the insert molding step, a heat radiating plate 14 is arranged in the internal space of the mold D for the housing, and a predetermined resin is provided in the internal space so that only the heat radiating protrusion 14B portion is exposed. Is injected and insert molded. By insert molding, the heat radiating plate 14 is integrated with the housing body 11, and the inner wall portion 11A, the outer wall portion 11B, and the embankment portion 11C having an area including the heat collecting portion 14A are simultaneously formed inside the wall of the housing. .. Next, the molded product is taken out from the mold D, and burrs and the like are removed.

As shown in FIG. 4, in the component arranging step, the heat conductive sheet 16 is directly stretched on the fixed portion of the inner wall portion 11A of the housing main body 11. After that, the substrate assembly of the electronic circuit 18 on which the electronic component 17 as a heating element is mounted is fixed with a constant load by screws or the like (not shown).

As shown in FIG. 5, in the sealing step, the flange 12F of the lid 12 is aligned with the flange 11F of the housing body 11, and the side surfaces of the flanges are face-joined to each other, and the flanges are fixed by screws or the like (not shown). Fix with load. As a result, the housing 10 of the sealed electronic device accommodating the electronic component 17 is completed. A connection hole (not shown) for passing an external power supply cable, an input / output cable, etc. for operating the housed electronic circuit is provided on the back surface 13 of the housing body 11 or a part of the side wall. ing.

The operation of the housing will be described with reference to FIG.

When the electronic component 17 generates heat due to the operation of the device, most of the heat (black arrow) is transferred to the heat conductive sheet 16 via the electronic circuit 18, and further, the inner wall portion 11A and the heat sink 14 provided in the housing body 11 Heat is transferred in the order of the mounting bracket 15, and finally is radiated to the atmosphere from the heat sink 14 and the mounting bracket 15.

At this time, the inside of the housing is sealed from the outside air by the inner wall portion 11A integrally formed with the housing main body 11.

As described above, according to the present embodiment, by insert-molding the housing body 11 and the heat radiating plate 14, the heat radiating plate 14 and the housing body 11 have high adhesion and the contact thermal resistance of the boundary surface is small. The heat is efficiently transferred to the heat radiating plate 14, and by exposing a part of the heat radiating plate 14 to the atmosphere, the heat is directly released to the atmosphere without passing through the housing body 11. Further, by providing the mounting hole 19 in the heat radiating plate 14, the mounting bracket 15 can be directly fixed to the heat radiating plate 14, and the mounting bracket 15 can also be used as a heat radiating body.

Further, by forming the inner wall portion 11A and the outer wall portion 11B at the same time when the heat radiating plate 14 and the housing main body 11 are insert-molded inside the housing, the airtightness inside the housing can be ensured, and the electronic components 17 and electrons can be secured. The conventional sealing plastic or the like for protecting the circuit 18 becomes unnecessary. From the above, in the heat radiating structure of the resin housing, the airtightness can be ensured and the heat radiating property can be expected to be improved.

Further, in addition to the effect of improving heat dissipation, the heat dissipation plate 14 and the housing body 11 are integrated, and the sealing plastic is not required, so that the assembly man-hours can be reduced, and further, the sealing plastic can be used. Since it is unnecessary, even if the board assembly of the electronic circuit 18 fails, it can be replaced.

In the above-described first embodiment, the heat-dissipating protrusions 14B of the exposed parts of the heat-dissipating plate 14 are provided at two points at both ends of the housing as attachment parts for fixing, but the heat-dissipating protrusions 14B are shaped to increase the exposed parts such as a heat sink shape. If so, the heat dissipation is further improved. For example, as shown in FIG. 7, in the second embodiment, three streaks of the heat-dissipating protrusion 14BB, which is shorter than these, may be provided between the two streaks of heat-dissipating protrusions 14B for attachment.

In the above-described first embodiment, the heat-dissipating protrusion 14B of the heat-dissipating plate 14 is provided on the mounting wall side as a mounting portion for fixing, but if the heat-dissipating plate 14 is provided on the side surface other than the back surface or the lid side, further heat dissipation can be achieved. Improve. For example, as shown in FIG. 8, in the third embodiment, the heat radiating plate 14 is insert-molded on the lid 12 side as well as the housing main body 11, and the electronic component 17 is brought into contact with the electronic component 17 via the heat conductive sheet 16 or the like. This further improves heat dissipation.

10 ... Housing 11 ... Housing body 12 ... Lid body 11A ... Inner wall part 11B ... Outer wall part 11C ... Filling part 11F, 12F ... Flange 13 ... Back surface 14 ... Heat sink 14A ... Heat collecting part 14B ... Heat dissipation protruding part 16 ... Heat Conduction sheet 15 ... Mounting bracket 17 ... Electronic component 18 ... Electronic circuit 19 ... Mounting hole P ... Wall Sc ... Screw SP ... Accommodation space

Claims (6)

A housing for an electronic device consisting of a lid and a housing body that define a sealed storage space for accommodating a substrate assembly including a substrate that carries an electronic circuit.
A wall portion that supports the substrate inside the housing body and
It has a heat sink that extends within the wall and has a higher thermal conductivity than the wall.
The wall portion is formed integrally with the heat radiating plate by the inner wall portion and the outer wall portion to embed sandwiching the radiator plate,
The accommodation space is sealed from the outside air by the inner wall portion having a fixing portion that is sandwiched between the heat sinks and the substrate is fixed inside the housing body.
A housing for an electronic device, wherein only a part of the heat radiating plate is exposed and protrudes from the outer wall portion only to the external space of the housing. The housing of an electronic device according to claim 1, wherein the protruding portion of the heat radiating plate is a mounting portion for fixing the housing. The housing of an electronic device according to claim 1 or 2, wherein a plurality of the protruding portions of the heat radiating plate are provided. The housing of an electronic device according to any one of claims 1 to 3, wherein an embankment portion that rises from the wall portion is provided around the root of the protruding portion of the heat radiating plate. The housing of an electronic device according to any one of claims 1 to 4, wherein the heat radiating plate is made of metal and the wall portion is made of resin. The housing of an electronic device according to any one of claims 1 to 5, wherein the heat radiating plate is insert-molded so as to be embedded in the wall portion.

Images