JP2007159320A - Electric connection box - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric connection box in which leak can be prevented at the portion extending from a circuit board in a plurality of bus bars. <P>SOLUTION: At the side frame portion 40A of a frame 40, an insulation rib 42 is projecting to enter between the extensions 13A of bus bars 13 and to abut against an insulating material layer 24 formed on the upper surface of a supporting plate 23 (surface opposing the extension 13A). Since each extension 13A of the bus bar 13 is partitioned by the insulation rib 42 and the insulating material layer 24, i.e. the periphery of the extension 13A of the bus bar 13 is surrounded by the insulating material layer 24 and the insulation rib 42, current leak is prevented between the bus bars 13 at the extension 13A. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electrical junction box.

The thing of patent document 1 is known as an electrical junction box mounted in a motor vehicle etc. The electrical junction box includes a circuit board and a plurality of bus bars bonded to the lower surface of the circuit board, and the bus bars are arranged by being bent upward at a position extending from the edge of the circuit board. ing. And the heat radiating member is adhere | attached on the lower surface of the bus-bar via the insulating adhesive agent.
JP 2003-164039 A

  However, in the structure as described above, if the space between the bus bars is very narrow due to space or the like, a portion of the bus bar extending from the edge of the circuit board may be short-circuited or a leakage current may flow. There is concern. Moreover, there is a possibility that water droplets may enter the upper surface of the heat radiating member due to rain, washing, etc., and it is particularly important to suppress leakage current at the portion of the bus bar that is disposed on the upper surface of the heat radiating member. .

  The present invention has been completed based on the above situation, and an object of the present invention is to provide an electrical junction box capable of preventing leakage at a portion extending from a circuit board in a plurality of bus bars.

  As means for achieving the above object, the invention of claim 1 is directed to a circuit board and a plurality of bus bars which are bonded to one surface side of the circuit board and are extended from the edge of the circuit board and arranged in parallel. And a frame formed along the parallel direction of the bus bar group at the edge of the circuit board, and the circuit board and the frame body are overlapped via an adhesive layer to dissipate heat from the circuit board and the bus bar. A heat dissipating member, a support plate part that is integrally extended to the heat dissipating member, and that opposes the extending portion of the bus bar group from the circuit board, and an insulating material layer is formed on the opposing surface, and the frame An electrical connection box provided with an insulating rib that protrudes from the body and enters between the extended portions of the bus bar from the circuit board and the edge on the support plate portion abuts against the insulating material layer. However, it has characteristics.

  The invention of claim 2 is characterized in that, in the invention of claim 1, the insulating material layer is an adhesive layer that adheres the heat dissipation member to the circuit board.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the bus bar is bent along the thickness direction of the circuit board at a portion extending from the circuit board, and the insulating rib is The bus bar extends from the bent portion to the opposite side of the circuit board.

  Invention of Claim 4 is a thing in any one of Claims 1-3. WHEREIN: The said bus-bar is bend | folded along the thickness direction of the said circuit board in the extension part from the said circuit board, The said The insulating rib is characterized in that it is disposed between the bent portions of the bus bar.

<Invention of Claim 1>
According to the first aspect of the present invention, the frame body includes an insulating material layer formed on a surface of the support plate portion facing the extending portion and entering between the extending portions of the bus bar from the circuit board. Insulating ribs that abut are projected. According to such a configuration, the extended portion of the bus bar from the circuit board is partitioned for each bus bar by the insulating rib and the insulating material layer, and thus leakage of this portion is prevented. In addition, since the insulating ribs are in contact with the insulating material layer and partitioned, it is possible to prevent leakage of electric current through the surface of the insulating material layer and arcing between the bus bars.

<Invention of Claim 2>
According to the invention of claim 2, since the insulating material layer is an adhesive layer for adhering the heat dissipation member to the circuit board, the adhesive used for adhering the heat dissipation member to the circuit board is removed from the circuit board of the bus bar. It can be used for the purpose of insulating the extended portion of the material, and the labor required for the work can be saved as compared with the case where the adhesive and the insulating material are applied separately.

<Invention of Claim 3>
According to the invention of claim 3, since the insulating rib extends to the opposite side of the circuit board from the bent portion of the bus bar, compared to the case where only the bent portion of the bus bar is partitioned by the insulating rib. The creepage distance in the direction along the plate surface direction of the circuit board between the bus bars increases, and the extension portion of the bus bar from the circuit board is less likely to leak.

<Invention of Claim 4>
According to invention of Claim 4, since the insulation rib is distribute | arranged between the bending parts of a bus-bar, the bending part of a bus-bar is each pinched | interposed with an insulation rib. Thereby, the position shift of the parallel direction of the extension part from a circuit board among bus bars is prevented.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 and 2 are an external perspective view and an exploded perspective view of the electrical junction box in the present embodiment, and FIG. 3 is a side view of the electrical junction box in the present embodiment.

The electrical junction box of the present embodiment is arranged on the substantially same plane as a power distribution board (not shown), accommodated in a casing, and used by being mounted on a vehicle. And the control circuit board 10 with which the electrical connection box was equipped, and a power distribution board are connected.
Hereinafter, in each component member, the upper side in FIG. 2 is described as an upper surface and the lower side is described as a lower surface.

  As shown in FIG. 2, the control circuit board 10 includes a circuit board 11 having a rectangular plate shape as a whole, and a conductor pattern (not shown) constituting the control circuit is formed on the upper surface thereof. In addition, an electrical component 12 such as a relay is mounted. A plurality of bus bars are attached to the lower surface of the circuit board 11 via an insulating thin adhesive sheet (not shown).

  The plurality of bus bars affixed to the lower surface of the circuit board 11 are formed by punching a metal plate having excellent conductivity to form a predetermined conductive path serving as a power circuit. In addition, a predetermined bus bar 13 of the bus bars is extended from one side edge of both long side edges of the circuit board 11 and connected to the power distribution board. The plurality of bus bars 13 are arranged in parallel with each other as narrow as possible for the sake of space. Each bus bar 13 has a shape that is bent at a right angle by 3 degrees so that the tip of the portion extends from the side edge of the circuit board 11 upward. Specifically, each bus bar 13 includes an extended portion 13A that slightly extends from the side edge portion of the circuit board 11 along the plate surface direction of the circuit board 11, and an upper side (circuit) from the extended end of the extended portion 13A. The rising portion 13B is bent in the direction along the thickness direction of the substrate 11, and is substantially horizontal with respect to the circuit substrate 11 from the rising end of the rising portion 13B toward the opposite side of the circuit substrate 11 again. The horizontal portion 13C is bent so as to be formed, and the connection piece portion 13D is bent substantially at a right angle so as to be directed upward from the tip of the horizontal portion 13C. The connection piece 13D is connected to the bus bar on the power distribution board side by welding. A number of through-holes 14 penetrating the control circuit board 10 in the thickness direction are arranged at one end in the longitudinal direction of the control circuit board 10.

  On the lower surface of the control circuit board 10, a heat sink 21 (corresponding to a heat dissipation member of the present invention) having a plate shape is overlapped via an insulating adhesive layer 20, and the relay mounted on the circuit board 11. The heat generated from the electrical component 12 and the bus bar is radiated from the heat radiating plate 21. The adhesive layer 20 is a range including at least the circuit board 11 and the extended portion 13A of the bus bar 13 on the upper surface (surface on the control circuit board 10 side) of the heat sink 21, in other words, a slight portion along the periphery of the heat sink 21. Is formed by an adhesive applied almost over the entire surface.

  The heat radiating plate 21 is made of a metal having a high thermal conductivity, such as aluminum, slightly larger than the outer shape of the circuit board 11 and has a substantially rectangular shape that can cover almost the entire surface except for the connection piece 13D of the bus bar 13. Yes. An opening 22 is formed in a portion of the heat sink 21 corresponding to the through hole 14 formed in the control circuit board 10 so as to penetrate the heat sink 21 in the thickness direction. It is opened below the plate 21.

  The edge corresponding to the bus bar 13 in the heat radiating plate 21 is a support plate 23 that faces the bus bar 13, and the end edge reaches a position corresponding to the position closer to the connecting piece 13 </ b> D in the horizontal portion 13 </ b> C of the bus bar 13. Yes. The support plate portion 23 supports the extending portion 13A of the bus bar 13 from the lower side, and the adhesive layer 20 disposed on the upper surface (opposing surface facing the bus bar 13) is the extending portion of the bus bar 13. An insulating material layer 24 that insulates 13A from the heat sink 21 is formed. In addition, from the edge of the heat sink 21 on the opposite side to the side on which the opening 22 is provided, the attachment piece 25 is formed in a posture that escapes obliquely downward.

  As shown in FIG. 3, a connector housing 30 is attached to the position corresponding to the opening 22 of the heat sink 21 from the lower surface side. The connector housing 30 includes a housing made of synthetic resin that opens downward, and a plurality of terminals 31 that penetrate the ceiling wall in the vertical direction (wall thickness direction) are provided on the ceiling wall of the housing. ing. One end of the plurality of terminals 31 is disposed in the housing, and the other end is press-fitted into the through hole 14 of the control circuit board 10 and is electrically connected to the circuit of the control circuit board 10.

  At the periphery of the control circuit board 10, a frame body 40 having a frame shape substantially along the periphery of the circuit board 11 is provided. The frame body 40 is made of an insulating material such as a synthetic resin, and has a substantially rectangular shape in which the circuit board 11 can be fitted almost tightly. A connecting portion 41 having a form in which both side frame portions on the long side of the frame body 40 are connected is formed at a substantially central position in the longitudinal direction of the frame body 40. In addition, the side frame portion 40A corresponding to the bus bar 13 extending from the side edge portion of the circuit board 11 among the both side frame portions on the long side is disposed closer to the circuit board 11 than the rising portion 13B of the bus bar 13. And the form along the parallel direction of this rising part 13B is comprised. The side frame portion 40A is arranged so as to overlap the upper side (the side opposite to the heat sink 21) of the extending portion 13A of the bus bar 13, and the outer side surface thereof is the surface on the circuit board 11 side in the rising portion 13B of the bus bar 13. It is the form which makes it substantially parallel and opposes. The vertical dimension of the frame body 40, that is, the vertical dimension of the side frame part 40A is slightly larger than the vertical dimension of the rising part 13B, and the upper surface of the side frame part 40A is slightly larger than the horizontal part 13C of the bus bar 13. It reaches up. The frame body 40 is fixed by being screwed to the peripheral portion of the heat radiating plate 21 with the side frame portion 40A sandwiching the extending portion 13A of the bus bar 13 with the heat radiating plate 21. Thereby, the heat sink 21 is in a state of closing the lower surface side of the frame body 40. Note that a cover (not shown) is placed on the upper surface side of the frame body 40.

  An insulating rib 42 protruding outward is provided on the outer side surface of the side frame portion 40A in the frame body 40. FIG. 4 shows a partially enlarged sectional view of the insulating rib 42 as viewed from the side. The insulating ribs 42 are provided for each corresponding position between the rising portions 13B of the bus bar 13 on the outer surface of the side frame portion 40A. Each insulating rib 42 has a wall shape provided so as to protrude above the support plate portion 23 from the outer peripheral surface of the side frame portion 40A to the end portion of the support plate portion 23 of the heat sink 21. The wall thickness is made slightly smaller than the gap dimension between the rising portions 13B. In other words, the insulating ribs 42 enter between the rising portions 13B and extend over the extending portion 13A of the bus bar 13 and outside the rising portion 13B (on the side opposite to the circuit board 11). ing.

  In addition, the upper end of the insulating rib 42 is substantially flush with the upper surface of the side frame portion 40A, while the lower end reaches a position protruding slightly below the lower surface position of the side frame portion 40A. The insulating rib 42 has a height dimension extending in the vertical direction of the rising portion 13B, and has a form of rising between the rising portions 13B so as to separate the rising portions 13B. And the lower end edge part 42A which protruded below the lower surface (the heat sink 21 side) of the side frame part 40A in the insulating rib 42 is directed to the inner side (circuit board 11 side) of the side frame part 40A. The bottom surface is also extended. The lower edge portion 42A protruding below the side frame portion 40A and the insulating rib 42 enters between the extended portions 13A of the bus bar 13 bonded to the upper surface of the support plate portion 23 via the insulating material layer 24. At the same time, the lower end edge (the end edge on the support plate portion 23 side) is adhered in a state of slightly biting into the insulating material layer 24 between the extending portions 13A. It should be noted that both side edges of the lower end edge portion 42A facing the extending portion 13A of the bus bar 13 are chamfered.

  Next, the operation and effect of the present embodiment configured as described above will be described. In the side frame portion 40A of the frame body 40, the insulating material layer 24 is formed between the extended portions 13A of the bus bar 13 and formed on the upper surface of the support plate portion 23 (opposite surface facing the extended portion 13A). An abutting insulating rib 42 projects. Thus, the extending portion 13A of the bus bar 13 is partitioned for each extending portion 13A by the insulating rib 42 and the insulating material layer 24, that is, the periphery of the extending portion 13A is surrounded by the insulating material layer 24 and the insulating rib 42. Therefore, current leakage between the bus bars 13 in the extending portion 13A is prevented. In particular, in the case where the bus bars 13 are arranged in parallel so as to be very narrow due to the space or the like as in this embodiment, for example, even if insulating ribs are arranged so as to partition the bus bars 13, for example. If there is a slight gap between the insulating rib and the upper surface of the support plate portion 23, current may flow through the upper surface of the support plate portion 23, or an arc may be generated between the bus bars 13. I can't deny it. Further, even if a small amount of moisture adheres to the upper surface of the support plate portion 23 due to rainfall or washing, it is possible to cause a short circuit. Therefore, it is particularly effective to provide such an insulating rib 42. is there.

  Further, since the insulating rib 42 is arranged over the extending portion 13A of the bus bar 13 and outside the rising portion 13B (on the side opposite to the circuit board 11), for example, the insulating rib 42 extends to the extending portion 13A. The creepage distance in the direction along the plate surface direction of the circuit board 11 between the extending portions 13A (the extending direction of the extending portion 13A) is increased compared to the case where the extending portion 13A is disposed. The part 13A is less likely to leak.

  In addition, the insulating ribs 42 are configured to rise between the rising portions 13B so as to separate the rising portions 13B of the respective bus bars 13, and the rising portions 13B of the bus bars 13 are sandwiched between the insulating ribs 42, respectively. It is in a state. As a result, the rising portion 13B is prevented from being displaced in the parallel direction, and the displacement of the bus bar 13 in the parallel direction is suppressed, so that the connection of the power distribution board to the bus bar is improved.

  Note that the adhesive layer 20 disposed for bonding the heat sink 21 and the circuit board 11 serves as an insulating material layer 24 that insulates the extending portion 13 </ b> A of the bus bar 13. Therefore, it is only necessary to apply the adhesive to a range including the portion corresponding to the circuit board 11 in the heat radiating plate 21 and the upper surface of the support plate portion 23, compared with the case where the adhesive and the insulating material are applied separately. This saves time and effort.

<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.

  (1) In the above embodiment, the heat dissipation plate 21 having a plate shape as the heat dissipation member is superimposed on the lower surface of the control circuit board 10, but the heat dissipation member does not necessarily have to be a plate shape. The heat dissipation member may include a plurality of fins.

  (2) In the above-described embodiment, each bus bar 13 has a form that is bent at a right angle of 3 degrees so that the tip of the bus bar 13 extends upward from the side edge of the circuit board 11. For example, the bus bar may be in the form of being bent in the direction of the plate surface of the circuit board without being bent, or in the form of being bent twice.

  (3) In the above embodiment, the side frame portion 40A of the frame body 40 is arranged closer to the circuit board 11 than the rising portion 13B of the bus bar 13, but the shape of the frame surrounds the rising portion of the bus bar. The side frame portion may be arranged outside the rising portion.

  (4) In the above embodiment, the lower end edge of the lower end edge portion 42A protruding below the side frame portion 40A and the insulating rib 42 is bonded in a state of slightly biting into the insulating material layer 24 between the extending portions 13A. However, as long as this lower end edge is in contact with at least the surface of the insulating material layer, it does not necessarily have to bite into this insulating material layer.

  (5) In the above embodiment, the bus bar 13 is connected to the power distribution board. However, the present invention is not limited to this. For example, the bus bar may be held by the connector housing and connected to the external connector.

External perspective view of electrical junction box in this embodiment The exploded perspective view of the electrical junction box in this embodiment Side view of electrical junction box in this embodiment Partial enlarged sectional view of the insulating rib as seen from the side

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Circuit board 13 ... Bus bar 13A ... Extension part (extension part from the circuit board of a bus bar group)
20 ... Adhesive layer 21 ... Heat dissipation plate (Heat dissipation member)
23 ... support plate part 24 ... insulating material layer 40A ... side frame part (frame body)
42. Insulating rib

Claims (4)

A circuit board and a plurality of bus bars which are bonded to one side of the circuit board and extend in parallel from the edge of the circuit board;
A frame formed along the parallel direction of the bus bar group at the edge of the circuit board;
A heat dissipating member for dissipating heat from the circuit board and the bus bar overlaid on the circuit board via an adhesive layer;
A support plate part that is integrally extended to the heat dissipating member and that opposes the extension part of the bus bar group from the circuit board, and has an insulating material layer formed on the opposing surface;
An electrical junction box provided with an insulating rib that protrudes from the frame and enters between a portion of the bus bar that extends from the circuit board, and an edge on the side of the support plate abuts against the insulating material layer . The electrical junction box according to claim 1, wherein the insulating material layer is an adhesive layer that adheres the heat dissipation member to the circuit board. The bus bar is bent along the thickness direction of the circuit board at a portion extending from the circuit board,
3. The electrical junction box according to claim 1, wherein the insulating rib extends to a side opposite to the circuit board from the bent portion of the bus bar. The bus bar is bent along the thickness direction of the circuit board at a portion extending from the circuit board,
The said junction rib is distribute | arranged between the bending parts in the said bus-bar, The electrical-connection box in any one of Claims 1-3 characterized by the above-mentioned.

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