JP5166945B2 - Heat dissipation structure for electrical junction box - Google Patents

Description

  The present invention relates to a heat dissipation structure for an electrical junction box that radiates heat by convection of air in the electrical junction box with a heating element in the electrical junction box.

  FIG. 8 shows an embodiment of a conventional heat dissipation structure for an electrical junction box (see Patent Document 1).

  In this structure, the thermoelectric cooling element 73 is provided on the synthetic resin lower cover 72 of the electric connection box 71 and the blower fan 74 electrically connected to the thermoelectric cooling element 73 is provided. When the temperature rises, it is cooled by the thermoelectric cooling element 73, and when the temperature difference between the inside and outside, that is, the temperature difference between the metal inner heat absorbing plate and the outer heat radiating plate of the thermoelectric cooling element 73 becomes larger, the blower fan 74 is automatically rotated. Thus, the air in the electrical junction box is convected.

  The electrical connection box 71 includes a frame 75 made of insulating resin, a fuse mounting portion 76 and a relay mounting portion 77 disposed in the frame, and upper and lower covers 78 and 72 covering the upper and lower openings of the frame 75. ing. The fuse 79 and the relay 80 serve as a heating element, the temperature in the electrical junction box rises, and the thermoelectric cooling element 73 and the blower fan 74 are activated to prevent overheating.

  A terminal (not shown) is accommodated in the fuse mounting portion 76 and the relay mounting portion 77, and the electric wire 81 connected to the terminal is led out from the mouth portion 82 on the lower side of the frame 75. The position of the blower fan 74 is not limited to the lower cover 72 and may be disposed on the lower side of the frame 75. As a conventional example of Patent Document 1, an example in which only the blower fan 74 is provided on the lower cover 72 and the frame 75 is described.

Patent Document 2 describes an example (not shown) in which a plurality of thermoelectric cooling elements (Peltier elements) are provided on an upper cover and a lower cover of an electrical junction box. Further, Patent Document 3 describes that an outward convex portion is formed to bulge on the upper cover of the electrical junction box, hot air is stored in the convex portion, and is cooled with outside air (not shown), In addition, examples of electronic components that are heating elements include diodes, ICs, transistors, resistors, capacitors, coils, relays, fuses, fusible links, and the like.
JP 2000-37017 A (FIG. 2) JP 2000-125441 A (FIG. 1) Japanese Patent Laid-Open No. 10-210629 (FIGS. 2 and 4)

  However, the conventional heat dissipation structure of the electrical junction box has a problem that the structure is increased in size, complexity, and cost by providing the thermoelectric cooling element 73 and the fan 74. Moreover, in the structure in which the convex portion for storing hot air is formed on the cover, there is a concern that a large heat dissipation effect cannot be expected because the convection of air in the electrical junction box is not actively performed, and the convex portion is outside. As a result, the electrical connection box is enlarged and the space is saved.

  In view of the above points, the present invention provides an electrical connection capable of exerting a heat dissipation effect by causing convection of air in the electrical junction box without increasing the size, complexity, and cost of the electrical junction box. It aims at providing the heat dissipation structure of a box.

In order to achieve the above object, a heat dissipation structure for an electrical junction box according to claim 1 of the present invention is such that a heating element is disposed in the middle in the height direction inside the electrical junction box, and the lower side of the electrical junction box And an exhaust port provided on the upper side of the electrical junction box, and air in the electrical junction box heated by the heating element is exhausted from the exhaust port. Rutotomoni, the heat radiation structure of an electric connection box outside air from the mouth for intake is Ru is introduced, the heating element is provided at the end of the connection block, by the connection block is assembled to the inside of the frame, the The heating element is arranged near or in the center of the electrical junction box including the connection block and the frame .

With the above configuration, the air heated by the heating element in the electrical junction box rises and is discharged to the outside through the upper exhaust port, and at the same time, the temperature in the electrical junction box from the lower intake port. Cooler outside air is led out to cool the inside of the electrical junction box. Circulation (convection) of air in the electrical junction box is performed by the heated air rising operation, the exhaust operation, and the outside air intake operation.
Also, the heating element is easily assembled to the end of the connection block with good workability, and the connection block is assembled in the frame to form the main part of the electrical junction box. (Centered) or placed in the center. The upper and lower covers are attached to the frame to form an electrical junction box. The connection block is a relay block or a fuse block.

  The heat dissipation structure of the electrical junction box according to claim 2 is the heat dissipation structure of the electrical junction box according to claim 1, wherein an air passage in a vertical direction is formed to penetrate from the heating element to an upper portion of the electrical junction box. The lower opening of the air passage communicates with the intake port, and the upper opening of the air passage communicates with the exhaust port.

  With the above configuration, air heated by the heating element is smoothly guided (guided) upward in the air passage, so that air in the electrical junction box is smoothly convected.

The heat dissipation structure of the electrical junction box according to claim 3 is the heat dissipation structure of the electrical junction box according to claim 1 or 2 , characterized in that the intake and exhaust ports are outlets for electric wires. To do.

  With the above-described configuration, intake and exhaust are performed through a gap between the inner surface of the wire outlet port and the outer surface of the wire. By using the wire outlet port, it is not necessary to provide an inlet / outlet port independently.

According to the first aspect of the present invention, by using a heating element that is normally arranged in the electrical junction box, intake and exhaust are performed at the mouth of the electrical junction box, so that a conventional fan or cooling unit can be used. Without using parts, the electrical junction box can be radiated by convection of the air in the electrical junction box without increasing the size, complexity, and cost of the electrical junction box.
In addition, the heating element can be easily assembled to the connection block, and the heating block can be easily arranged near or in the center of the electrical connection box by assembling the connection block in the frame. The convection of the air in the junction box can be performed uniformly, and the heat dissipation effect of the electrical junction box can be enhanced.

  According to the second aspect of the present invention, the air heated by the heating element is guided to the air passage and smoothly rises, so that the convection of the air in the electric junction box is smoothly and reliably performed. The heat dissipation of the box is improved.

According to the third aspect of the present invention, it is not necessary to provide an inlet / outlet port independently by using the wire outlet port portion as the intake / exhaust port portion. Simplification and cost reduction are achieved.

  1 to 7 show an embodiment of a heat dissipation structure for an electrical junction box according to the present invention.

  In this structure, a fusible link 2 for a large current as a heating element is disposed at a position near the center of the electrical junction box 1, and air in the electrical junction box is convected by heat generated by the fusible link 2. The cooling air is taken in from the lower opening 3 for leading out the electric wire (wire harness) of the electric connection box 1 and the heated air in the electric connection box is discharged from the upper openings 4 and 5 above the opening 3. In this way, the electrical junction box is made to dissipate heat.

  As shown in FIGS. 1 and 2, the electrical junction box 1 has a fusible link 2 for large current inside, a plurality of blade-shaped small fuses 8 on the top, a fusible link 9 for medium current, The relay 10 and the connector 11 are included. Reference numeral 12 denotes a horizontally long case-like board connection unit. The fusible link 2 is located in the middle in the height direction of the electrical junction box 1 and in the middle in the width (left and right) direction and in the longitudinal (front and rear) direction.

  The junction box body made of insulating resin in the electrical junction box 1 includes an intermediate frame 13, a relay block body 14 assembled from below in the frame, a lower cover 15 covering the lower opening of the frame 13, and an upper opening of the frame 13. And an upper cover 16 (FIG. 2) for covering.

  The high current fusible link 2 is attached to the lower part of the front end of the relay block main body 14, and the fuse 8, the medium current fusible link 9 and the board connecting unit 12 are inserted into the relay block main body 14 from above. A relay block (connection block substituted with reference numeral 14) is configured by mounting these electrical components and the like on the relay block body 14. At least the relay block 14 to which the fusible link 2 is mounted is slid and inserted upward in the frame 13, and the fusible link 2 is disposed at a position near the center of the electrical junction box 1.

  As shown in FIG. 3, the fusible link 2 is disposed at the lower front end of the relay block 14, and is disposed substantially at the center lower side of the frame 13 with the relay block 14 assembled to the frame 13. 15 (FIG. 1) is placed slightly above the lower cover 15, that is, approximately at the center in the height direction of the electrical junction box 1, and approximately at the center in the width direction of the electrical junction box 1 as shown in FIG. 2.

  As shown in FIG. 3, the relay block 14 is disposed substantially in the middle in the height direction of the frame 13, and a space 17 exists between the upper and lower ends of the relay block 14 and the upper and lower ends of the frame 13. A plurality of electric wires (wire harnesses) (not shown) led downward from the connectors 18 and 20 on the lower side of the relay block 14 pass through the inner space 19 of the lower cover 15 from the lower space 17 of the frame 13 and the mouth of the junction box body. Derived from the parts 3 and 6 to the outside. The connector 18 is formed on the relay block body, and the connector 20 is formed on the board connection unit 12.

  As shown in FIGS. 1 to 3, in the electrical junction box 1 of this example, the mouth portions 3 to 7 are provided at several locations on the outer wall side of the electrical junction box 1. The mouth portions 3, 6, and 7 are configured in a cylindrical shape by vertically joining half-divided hook-shaped portions formed on the lower end portion of the frame 13 and the upper end portion of the lower cover 5. Or the mouth part 3 is comprised by the half-shaped hook-shaped part by the side of a frame. Needless to say, each of the mouth portions 3 to 7 communicates with the space within the frame 13 or the lower cover 15, that is, the electrical connection box 1.

  Each of the mouth portions 3 to 7 is provided at a front end, a rear end, and a rear end side portion of the electric junction box. For example, the front end mouth portion 3 (FIGS. 2 and 4) functions as a cooling air intake port. A plurality of electric wires (not shown) are led out to the mouth portion 3 and wound and fixed with a tape or the like. The gap between the outer peripheral surface of the electric wire and the inner peripheral surface of the mouth portion 3 is indicated by an arrow D in FIG. Thus, low temperature outside air is introduced into the electrical junction box.

  As shown in FIG. 1 (enlarged view in a circle) and FIG. 3, the fusible link 2 is disposed so as to be exposed in the electric junction box, and an air passage 21 is formed in the electric junction box upward from the front side of the fusible link 2. The air passage 21 opens to the upper and lower portions of the relay block 14 (the upper opening is indicated by reference numeral 21a and the lower opening is indicated by reference numeral 21b), and penetrates vertically in the electrical junction box. The fusible link 2 is disposed adjacent to the lower opening 21b.

  The upper opening 21 a is provided on the upper wall 22 of the frame 13, the connector 11 on the frame 13 side and the vertical partition wall 23 are located around the front opening 21 a (front side), and the relay block 14 is located on the rear side of the partition wall 23. . The connector 11 is a mating connector with an electric wire fitted into the connector housing of the frame 13 from above.

  As shown in FIG. 3, an electric wire 24 is led out from the mating connector 11 in a mountain shape and passes through wire insertion paths 4 ′ and 5 ′ along a vertical front wall (outer wall) 25 of the frame 13 as shown in FIGS. It is led out to the outside from the lower mouth portions 4 and 5 of the insertion passages 4 ′ and 5 ′. The electric wire insertion paths 4 'and 5' in this example are arranged in parallel on the left and right sides, and are configured inside side covers 26 and 27 that can be opened and closed, respectively. In the specification, the front / rear and left / right directions are for convenience of explanation.

  The upper mouth portions of the wire insertion passages 4 ′ and 5 ′ (represented by reference numerals 4 ′ and 5 ′) are located at the upper end of the frame 13, and the lower mouth portions 4 and 5 of the wire insertion passages 4 ′ and 5 ′ are Located at the lower end of the frame 13. The lower mouth parts 4 and 5 are located above (higher position) than the mouth part (air intake port) 3 at the front end of the electrical junction box 1 in FIG. The wire insertion passages 4 ′ and 5 ′ function as a heated air discharge path, and the lower ports 4 and 5 function as a heated air discharge port. Heated air is discharged to the outside through a gap between the inner peripheral surface of the wire insertion paths 4 ′ and 5 ′ and the outer peripheral surface of the electric wire 24.

  As shown in FIG. 3, the air heated by the fusible link 2 ascends in the air passage 21 as indicated by an arrow E and reaches above the relay block 14 (inside the space inside the upper cover 16). As described above, the wire passes through the wire insertion passages 4 'and 5' from the top to the bottom, and is discharged from the lower ports 4 and 5 to the outside. At the same time, external low-temperature air (air having a temperature lower than that in the electrical junction box) is taken into the electrical junction box from the lower opening 3 as indicated by an arrow D in FIG.

  As the air circulates (convects) in the electrical junction box as indicated by arrows D to F, the heated air in the electrical junction box is efficiently discharged to the outside, and at the same time, outside air is taken in. The temperature of the inside decreases (it is prevented from rising more than necessary).

  Arrows D to F indicate air convection in the first half of the electrical junction box 1, but air convection is similarly performed in the latter half of the electrical junction box 1. That is, outside air is taken in from the low-position mouth 6 (FIG. 4) on the rear end side of the electrical connection box 1 due to heat generated by the fusible link 2, and at the same time, the high-position mouth on the rear end of the electrical connection box 1 7 (FIG. 4) discharges the heated air in the electrical junction box. Thereby, air convection is performed in the electrical junction box symmetrically with the arrows D to F in FIGS.

  Of course, the air introduced from the mouth portion 6 at the lower position of the rear end is discharged from the mouth portions 4 and 5 (FIG. 5) at the higher position of the front end, or introduced from the mouth portion 3 (FIG. 4) at the lower position of the front end. The discharged air may be discharged from the mouth portion 7 at a high position at the rear end. In this way, the air in the electrical junction box is uniformly convected in the front-rear direction by the fusible link 2 that is a heating element disposed substantially near the center of the electrical junction box 1, so that the electrical junction box 1 can efficiently dissipate heat. Done.

  The lower mouth portions 3 and 6 are positioned lower (lower) than the fusible link 2, and the upper mouth portion 7 and the upper openings of the wire insertion paths 4 ′ and 5 ′ (reference numerals 4 ′ and 5 in FIG. 1). The “substitute” is located above (higher) the fusible link 2. Thereby, the convection of the air by the heat | fever of the fusible link 2 is performed smoothly and reliably.

As shown in FIG. 6, the fusible link 2 is mounted in a horizontally long opening 31 at the lower front end of the relay block body 14. In the block main body 14, two left and right bus bars 28 , 29 and nuts (not shown) of FIG. 7 are inserted in advance from below, and a pair of left and right plate-like terminals 2 a of the fusible link 2 are bolts 30 and nuts. The bus bars 28 and 29 are tightened and connected to holes (not shown) at the front ends.

  As shown in FIG. 7, the terminal 2a of the fusible link 2 is integrated with the narrow soluble portion 2b in the insulating resin case 2c, and the soluble portion 2b becomes hot when energized and heats the surrounding air. As shown in FIG.

  Each bus bar 28, 29 has a pin terminal 32 for connecting a fuse and a tab terminal 33, 34 for connecting a connector in an upward direction, and the pin 32 is connected to the fuse 8 in the fuse mounting portion at the top of the relay block 14. The tab terminals 33 and 34 are accommodated in the connector housings 35 and 36 in the upper part of the relay block 14 to form a connector, or are connected to the relay 10 and the fusible link 9 for medium current (FIG. 1).

A tab terminal 34 at the front end of one bus bar 28 is housed in a connector housing 36 at the front end of the relay block 14 and is connected to a terminal (not shown) with a wire from the positive electrode of a battery of an automobile. Another bus bar 37 in FIG. 6 is connected to the other bus bar 29 by bolts 30, and terminals 39 with electric wires from the alternator are connected to the other bus bars 37 by bolts 38.

  In FIG. 6, reference numeral 23 denotes a partition in the frame, reference numeral 11 denotes a connector housing of the frame 13, reference numeral 3 denotes a lower opening as an air intake, and reference numerals 4 and 5 denote wire insertion paths 4 ′ as air discharge openings. A lower opening portion 5 ', 40 is a side cover forming one electric wire insertion passage 5', and 14 'is a relay block body made of insulating resin.

  The fuse block 14 is disposed on the rear side of the partition wall 23. The side cover 40 sets the terminal 39 with electric wire in the opening 41 of the side wall (outer wall) 42 of the frame 13 and fixes it with the bolt 38 on the relay block 14 side, and then slides into the side opening 41 from above. Is done. The same applies to the side cover 26 at the front end in FIG. The relay block 14 is fixed to the frame 13 by a locking means such as a locking claw and an engagement frame piece, and the upper and lower covers 16 and 15 are fixed to the frame by a locking means 43 such as a locking claw and an engagement frame piece. The frame 13 is fixed to a vehicle body (not shown) with a locking clip 44 and a bracket 45.

  In the above-described embodiment, the wire outlet ports are used as the intake ports 3 and 6 and the exhaust ports 4, 5, and 7. If the gap between the outer surface and the outer surface is small and insufficient for intake / exhaust, it is possible to provide an inlet / outlet (hole or opening) for intake / exhaust on the frame 13 or the lower cover 15 or the like. .

  Moreover, in the said embodiment, although the fusible link 2 was used as a heat generating body, it can replace with the fusible link 2 and can use the relay, fuse, etc. (not shown) for large currents.

  Moreover, in the said embodiment, although the electrical junction box 1 was comprised by the relay block 14, the flame | frame 13, and each cover 15 and 16, for example, without using the flame | frame 13, the connection box main body (not shown) of an integral resin molding type | mold It is also possible to dispose the heating element 2 inside, and to provide the intake ports 3 and 5 at the lower part of the junction box body and the exhaust ports 4, 5 and 7 at the upper part, respectively. However, in this case, it is difficult or troublesome to assemble the heating element 2 at the center or near the center of the junction box body (electric junction box).

  Moreover, in the said embodiment, although the relay block 14 was accommodated in the flame | frame 13, it can replace with the relay block 14 and a fuse block, a connector block, etc. (not shown) can also be accommodated in a flame | frame, These The relay block 14, the fuse block, and the like can be collectively referred to as a connection block.

  In addition to the heat dissipation structure of the electrical junction box, the configuration of the present invention described above is also effective as the electrical junction box 1 itself, the heat dissipation method of the electrical junction box, and the like.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an embodiment of a heat dissipation structure for an electric junction box according to the present invention (enlarged view in a circle). It is a top view which shows an electrical junction box (an upper cover is shown with a chain line). It is AA sectional drawing of FIG. 2 which shows the thermal convection state of an electrical junction box. It is BB sectional drawing of FIG. 2 which shows the inhalation | air_intake state of an electrical junction box. It is CC sectional drawing of FIG. 2 which shows the exhaust condition of an electrical junction box. It is a disassembled perspective view which shows the block part and frame part of an electrical junction box. It is a perspective view which shows the connection state of the fusible link accommodated in a block part, and a bus bar. It is a longitudinal cross-sectional view which shows one form of the thermal radiation structure of the conventional electrical junction box.

Explanation of symbols

1 Electrical junction box 2 Fusible link (heating element)
3,6 Intake port 4,5,7 Exhaust port 13 Frame 14 Relay block (connection block)
21 Air passage 21a Upper opening 21b Lower opening

Claims (3)

Inside the electrical junction box, a heating element is disposed in the middle in the height direction, an intake port is provided on the lower side of the electrical junction box, and an exhaust port is provided on the upper side of the electrical junction box. provided, together with the air in an electric connection box which is heated by the heat generating body is discharged from the mouth for the exhaust, the heat radiation structure of an electric connection box outside air from the mouth for intake is Ru is introduced,
The heating element is provided at an end of the connection block, and the connection block is assembled to the inside of the frame, so that the heating element is located near or in the center of the electrical connection box including the connection block and the frame. An electrical junction box heat dissipation structure characterized by being arranged .   A vertical air passage is formed penetrating from the heating element to the upper part of the electrical junction box, a lower opening of the air passage communicates with the intake port, and an upper opening of the air passage is the exhaust port. The heat dissipation structure for an electrical junction box according to claim 1, wherein the heat dissipation structure communicates with the portion. Heat radiation structure of an electric connection box according to claim 1 or 2, wherein the mouth of the exhaust and for the intake is the mouth of a derivation wire.

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