JP2005268491A - Electrical connection box - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve heat dissipation efficiency with a simple structure. <P>SOLUTION: A heatsink 35 is fixed to a substrate 30, and a heating part SSR40 mounted on the substrate 30 is brought into contact with the heatsink 35. While a projection 37 is formed in a back plate 36A of the heatsink 35, the aperture of a window hole 24 is arranged at the cover 20 of a box 12. The heatsink 35 is sandwiched by packings 45, and fixed to the inner surface side of the cover 20 via the window hole 24 of the injection 37 with screws 25. The projection 37 of the heat sink 35 projects outside through the window hole 24, so that the packings 45 carries out the sealing between the window hole 24 and the projection 37. Since it has such a structure that the projection 37 which is a part of the heatsink 35 may come into contact with the open air directly, the heat generation of the heating part SSR40 can be diffused well to the open air, that is, the heat can be dissipated efficiently. Moreover, since it has such a simple structure that severe accuracy may not be required for its manufacturing and administration, the manufacturing cost can also be controlled at a low cost. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electrical box having an improved heat dissipation structure.

  In a refrigerator, an electrical box is provided to perform power feeding and control signal transmission, and is installed in a machine room in which, for example, a refrigeration apparatus is accommodated. In this electrical box, a microcomputer and various electrical components are mounted on a printed circuit board, and these are housed in the box. Recently, however, as electrical components, heat generation such as SSR (solid state relay) and FETs has occurred. There is a tendency for many parts to be used, and heat dissipation is an important problem (for example, see Patent Document 1).

Conventionally, as an example of the countermeasure, the box is formed of a heat-conductive metal plate, and a heat sink having a gate shape is also formed of the heat-conductive material and fixed on the printed circuit board. The heat generating component is brought into contact with the side plate and the ceiling plate of the heat radiating plate is fixed in close contact with the box, whereby the heat of the heat generating component is dissipated from the outer surface of the box to the outside air through the heat radiating plate.
JP 2001-276464 A

However, in the above-mentioned conventional one, since there is a plane contact portion between planes such as the ceiling plate of the heat sink and the peripheral surface of the box in the heat dissipation path, if the plane is distorted, the contact area is reduced as it is, and the heat dissipation efficiency is improved. There was a problem of lowering. In order to avoid this, it is necessary to increase the accuracy of the plane, but there is a possibility that the manufacturing and management become difficult and the manufacturing cost increases.
The present invention has been completed based on the above situation, and is to improve the heat dissipation efficiency with a simple structure.

As means for achieving the above object, according to the invention of claim 1, the substrate having the conductive path is provided with various electric components and a heat sink in contact with the heat generating component, and these are provided in the box. The accommodated electrical equipment box is characterized in that a window hole is opened on the peripheral surface of the box, and the heat sink is arranged to close the window hole.
The invention of claim 2 is characterized in that, in the invention of claim 1, the closed portion of the window hole in the heat radiating plate is provided with a protrusion protruding outside through the window hole.

The invention of claim 3 is characterized in that, in the one of claim 1 or claim 2, a packing made of an elastic material is sandwiched between a mouth edge of the window hole and the heat radiating plate. Have.
According to a fourth aspect of the present invention, the electrical equipment box according to any one of the first to third aspects is provided in a machine room that houses a refrigeration apparatus including a compressor, an air-cooled condenser, and the like. The window hole of the box is characterized in that it is provided facing the cooling air flow path of the condenser or the like.

<Invention of Claim 1>
Since a part of the heat radiating plate directly contacts the outside air through the window hole, heat can be radiated efficiently. In addition, since strict accuracy is not required in manufacturing and management, the manufacturing cost can be reduced.
<Invention of Claim 2>
Since the protrusion of the heat radiating plate protrudes into the outside air through the window hole, it becomes easier to come into contact with the outside air, and the heat radiation efficiency is further improved.

<Invention of Claim 3>
The packing prevents foreign matter from entering the box through the window hole. In addition, when the electrical box is installed at a location that receives vibration, the vibration is suppressed from being absorbed by the packing and transmitted to the substrate side.
<Invention of Claim 4>
Since a part of the heat radiating plate is exposed to the cooling air used for cooling the refrigeration apparatus, effective heat radiation is achieved.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
<Embodiment 1>
A first embodiment of the present invention will be described with reference to FIGS. In this embodiment, the relay box 10 equipped in the refrigerator is illustrated.
As shown in FIG. 1, the relay box 10 is roughly structured such that a microcomputer and various electrical components are mounted on a substrate 30 and a heat radiating plate 35 is provided, and these are accommodated in the box 12. ing.
In the following description, the left side of FIG.

As shown in FIG. 4, the box 12 includes a box body 13 and a cover 20. The box body 13 is made of a metal plate, and is formed in a horizontally long box shape with an upper surface and a rear surface opened. A rising plate 15 is bent at the rear edge of the bottom plate 14, and left and right side plates 16. In addition, a flange 18 is bent inward at the upper edge of the front plate 17.
One cover 20 is made of a heat conductive metal plate, for example, an aluminum plate, and is formed in an L-shaped cross section covering the upper surface of the box body 13 and the opening on the rear surface. On the lower edge of the rear plate 21, a hook plate 22 is bent forward. In addition, a window hole 24 having a slightly elongated rectangular shape is opened at the center of the rear plate 21. Insertion holes 26 for screws 25 (see FIG. 6) are formed at substantially four corners around the window hole 24.

The board 30 is obtained by assembling two printed circuit boards 31A and 31B with a spacer 32 between them, and various electric components are mounted on the board 30.
A heat radiating plate 35 is attached to the center of the back surface of the substrate 30. This heat radiating plate 35 is made of aluminum die cast, which is also a heat conductive material, and is formed in a thick channel shape as shown in FIG. 5, and as shown in FIG. The length is slightly shorter than the dimension, and the width is about 1/3 of the lateral dimension of the substrate 30.

A protrusion 37 having a front square shape that is slightly smaller than the window hole 24 of the cover 20 is formed at the center of the rear plate 36A of the heat radiating plate 35. The protrusion 37 has a thickness that is greater than the thickness of the heat sink 35 itself. A screw hole 38 into which the screw 25 is screwed is formed in alignment with the insertion hole 26 of the cover 20 at positions around the four corners of the protrusion 37 on the rear plate 36A of the heat radiating plate 35. .
The heat radiating plate 35 is applied in a vertically oriented posture at substantially the center of the back surface of the printed circuit board 31B on the back side, and as shown in FIG. It is fixed by screwing screws 39 from the surface side of the circuit board 31B.

  For example, the SSR 40 (solid state relay), which is a heat generating component among the electrical components, is disposed outside the side plate 36B of the heat radiating plate 35, and the lead wire 41 is inserted into the through hole of the printed circuit board 31A and soldered. As a result, the SSR 40 is abutted against the outer surface of the side plate 36B of the heat radiating plate 35 using the elasticity of the lead wire 41.

  A packing 45 is attached to the edge of the cover 20 on the inner surface side of the window hole 24. The packing 45 is made of, for example, silicon rubber, and is excellent in heat resistance, in addition to being highly elastic, and has better heat conductivity than a synthetic resin material. As shown in FIG. 6, it has a rectangular frame shape that can be fitted around the projection 37 of the heat radiating plate 35 and hits the rim on the inner surface side of the window hole 24, and is almost at the four corners. The insertion hole 46 of the screw 25 is formed in alignment with the insertion hole 26 of the cover 20 and the screw hole 38 of the heat radiating plate 35.

An example of the assembly procedure will be described. First, the heat sink 35 is applied to the back surface of the printed circuit board 31B on the back side, and is fixed with screws 39 from the front side. Subsequently, the printed circuit board 31A on the front side is assembled to complete the board 30.
A microcomputer and various electrical components are mounted on such a substrate 30. Among them, the SSR 40 which is a heat generating component is mounted on the substrate 30 and abutted against the side plate 36B of the heat radiating plate 35 as described above.

  When the mounting of the electrical components and the like on the substrate 30 is completed, as shown in FIG. 6, after the packing 45 is fitted around the projection 37 in the heat radiating plate 35, the projection 37 is fitted in the window hole 24 of the cover 20, Screws 25 are passed through the insertion holes 26 and 46 of the cover 20 and the packing 45 at four locations around the window hole 24, and are screwed into the screw holes 38 of the rear plate 36A of the heat radiating plate 35 to be tightened. The heat radiating plate 35 and the substrate 30 are attached to the front side (inside) of the rear plate 21 with the packing 45 interposed therebetween.

  Thus, the cover 20 integrally provided with the heat sink 35 and the substrate 30 is put on the box body 13, and as shown in FIG. 1, a portion extending from the lower edge of the rear plate 21 of the cover 20 to the retaining plate 22 is formed. The box body 13 is overlaid on the outside of the portion extending from the rising plate 15 to the front edge of the bottom plate 14, and the peripheral edge of the top plate 23 of the cover 20 is overlaid on the flange 18 on the upper edge of the box body 13, so It is fixed by being stopped with a screw 48 or the like.

  As a result, as shown in FIG. 3, the assembly of the relay box 10 in which the board 30 on which various electrical components are mounted and the heat radiating plate 35 are accommodated in the box 12 is completed. At this time, as shown in FIG. 1, the projecting portion 37 of the heat radiating plate 35 projects to the outside through the window hole 24 of the cover 20. Further, the packing 45 is elastically sandwiched between the rim on the inner surface side of the window hole 24 and a portion around the protrusion 37 on the rear surface plate 36 </ b> A of the heat radiating plate 35. The gap is sealed.

The relay box 10 is installed in the machine room 50 of the refrigerator. As shown in FIG. 7, the machine room 50 is provided on the upper surface of the refrigerator main body 51, and is formed in a form in which three surfaces are covered with a front panel 52 and left and right side panels 53. A heat insulating unit base 54 is mounted so as to cover an opening formed in the bottom surface of the machine room 50 (the ceiling wall of the refrigerator main body 51). A refrigeration unit 55 is installed on the unit base 54. For example, a condenser 56 including a condenser fan 56A and a compressor 57 are mounted side by side at a position on the left side when viewed from the front. The refrigeration apparatus 55 is circulated and connected by a cooler (not shown) disposed on the ceiling portion in the refrigerator main body 51 and a refrigerant pipe to form a known refrigeration cycle.
The relay box 10 is attached to a front edge portion on the right side as viewed from the front on the unit base 54 with a projection 37 of the heat radiating plate 35 facing rearward by a bracket (not shown) or the like.

  This embodiment has the structure as described above, and when the refrigeration apparatus 55 (compressor 57) is driven, the cool air generated in the vicinity of the cooler is circulated in the refrigerator, thereby cooling the interior. The At this time, the condenser fan 56A is also driven, and as shown by the arrow in FIG. 7, outside air is sucked from the air inlet and the upper surface opening provided in the front panel 52, and passes through the condenser 56 and circulates. Then, the condenser 56 and the like are cooled. A part of the cooling air flows through the rear of the protrusion 37 of the heat radiating plate 35 protruding to the rear surface side of the relay box 10.

On the other hand, the SSR 40 in the relay box 10 generates heat when energized, but this SSR 40 is applied to the heat radiating plate 35, and the heat radiating plate 35 particularly has a projection 37 protruding outside the box 12, and is cooled behind it. Since the working air is circulated, heat exchange between the heat radiating plate 35 and the outside air is efficiently performed, that is, the heat generated by the SSR 40 as the heat generating portion is efficiently dissipated into the outside air, and the temperature rise in the box 12 is increased. It can be suppressed.
The heat radiating plate 35 is also applied to the heat conductive cover 20 via the packing 45 having relatively excellent heat conductivity, so that indirect heat radiation by the cover 20 is also supplementarily performed.

  As described above, according to the present embodiment, the protrusion 37 provided on the heat radiating plate 35 protrudes to the outside through the window hole 24 of the cover 20 and comes into direct contact with the outside air. Can radiate heat efficiently. Therefore, the temperature rise in the box 12 is more reliably suppressed, and damage to the electrical components mounted on the board 30 can be prevented. Moreover, structurally, since the protrusion 37 is provided on the heat radiating plate 35 and only protrudes from the window hole 24 of the cover 20, strict accuracy is not required in manufacturing and management, and the manufacturing cost is reduced. Can also be kept inexpensive.

Since the packing 45 is sandwiched and sealed with the heat radiating plate 35 at the rim on the inner surface side of the window hole 24 of the cover 20, foreign matter can be prevented from entering the box 12. Further, by fixing the heat radiating plate 35 to the cover 20, the substrate 30 is naturally fixed to the cover 20, so that the assembling work is simplified.
Further, as in the present embodiment, when the relay box 10 is installed on the unit base 54 on which the refrigeration apparatus 55 is mounted, it can be said that the relay box 10 is easily affected by the vibration of the compressor 57, but the vibration transmitted to the box 12 is , Absorption by the packing 45 rich in elasticity and transmission to the substrate 30 are suppressed.

<Related technologies>
As shown by a chain line in FIG. 1, a thermistor element 59 for detecting the temperature in the box 12 is provided on the front side of the printed circuit board 31A on the front side constituting the board 30, and a warning is given if the detected temperature exceeds the set temperature. In this case, it is possible to prevent the temperature inside the box 12 from excessively rising.
In this type of refrigerator, the temperature of each part is detected by controlling the on / off of the refrigeration device 55 according to the temperature detected in the refrigerator, or controlling the stop of the defrosting operation according to the temperature detected by the cooler. However, if the same thermistor element 59 is used, control of temperature rise suppression in the box 12 can be easily dealt with by slightly changing the software of the microcomputer.
Further, since the thermistor element 59 is attached to the substrate 30, a special mounting plate can be dispensed with, and the structure becomes simple. Further, since the substrate 30 is hardly subject to vibration, the thermistor element 59 is also prevented from being damaged. It is. In addition, by being attached to the side opposite to the heat generating component such as the front side of the substrate 30, malfunction due to steady heat generation of the heat generating component can be prevented.

<Embodiment 2>
FIG. 8 shows Embodiment 2 of the present invention. In the second embodiment, the shape of the protrusion 61 protruding into the outside air in the heat radiating plate 60 is changed, that is, a plurality of vertical grooves 62 are formed on the protruding surface of the protrusion 61 at a constant pitch. Has been.
With this structure, the contact area with the outside air is greatly increased by the side surfaces and the bottom surface of the vertical groove 62, and the heat dissipation efficiency can be further increased.

<Embodiment 3>
FIG. 9 shows Embodiment 3 of the present invention. The present invention can be similarly applied to the control box 65 provided on the front panel 52 of the machine room 50 of the refrigerator.
As in the first embodiment, the control box 65 includes a board 30 on which a microcomputer and various electrical components are mounted and a heat radiating plate 35 housed in the box 12. In addition, an operation panel is provided on the front surface of the box 12. It has a provided structure. Therefore, the protrusion 37 provided on the heat radiating plate 35 is provided in a state of protruding from the rear surface of the box 12.

  According to the third embodiment, the cooling fan 56A is driven during the cooling operation so that the cooling air flows for cooling the condenser 56 and the like, and a part of the cooling air flows behind the control box 65. It flows through the rear of the protruding portion 37 of the protruding heat sink 35. Here, since the cooling air flowing behind the protrusion 37 is low-temperature air before heat exchange with the condenser 56, in the case of the control box 65, the protrusion 37 of the heat sink 35 is As a result, the heat radiation efficiency is extremely improved.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention, and further, within the scope not departing from the gist of the invention other than the following. Various modifications can be made.
(1) It is possible to make a part of the heat sink directly contact with the outside air through the window hole just by opening a window hole in the box cover and arranging the heat sink so as to close the window hole from the inside. Since the heat radiation efficiency can be improved, such a thing is also included in the technical scope of the present invention.
(2) The electrical box of the present invention is not limited to the place where the outside air such as cooling air is circulated as exemplified in the above embodiment, but is installed as long as the heat sink is a place where the outside air can be in direct contact with the outside air. The location is arbitrary.
(3) The present invention is not limited to the electrical box for refrigerators exemplified in the above embodiment, and the electrical equipment box is generally composed of heat-generating components housed in a box, even if it is equipped in other equipment. Can be widely applied to.

1 is a side sectional view of a relay box according to Embodiment 1 of the present invention. Partial cutaway front view Perspective view Exploded perspective view of the box Perspective view of heat sink Exploded perspective view showing the structure of the part where the heat sink is attached to the cover Schematic plan view showing the machine room of the refrigerator The perspective view of the heat sink which concerns on Embodiment 2. FIG. Schematic top view which shows the machine room of the refrigerator which concerns on Embodiment 3.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Relay box (electrical equipment box) 12 ... Box 13 ... Box main body 20 ... Cover 24 ... Window hole 25 ... Screw 30 ... Substrate 35 ... Radiation plate 36A ... Rear plate 37 ... Projection 40 ... SSR (heating component) 45 ... Packing DESCRIPTION OF SYMBOLS 50 ... Machine room 55 ... Refrigeration apparatus 56 ... Condenser 56A ... Condenser fan 57 ... Compressor 60 ... Radiator 61 ... Projection 62 ... Vertical groove (groove) 65 ... Control box (electrical equipment box)

Claims (4)

A substrate having a conductive path is provided with various electrical components and a heat sink that is in contact with the heat-generating component. In the electrical box in which these components are housed in the box, a window hole is opened on the peripheral surface of the box. The electrical box is characterized in that the heat radiating plate is disposed so as to close the window hole. 2. The electrical box according to claim 1, wherein a projecting portion that protrudes to the outside through the window hole is provided at a closed portion of the window hole in the heat radiating plate. The electrical box according to claim 1 or 2, wherein a packing made of an elastic material is sandwiched between a mouth edge of the window hole and the heat radiating plate. The electrical box is equipped in a machine room containing a refrigeration apparatus equipped with a compressor, an air-cooled condenser, etc., and the window hole of the box faces the cooling air flow path of the condenser, etc. The electrical equipment box according to claim 1, wherein the electrical equipment box is provided.

Images