JP4453029B2 - Electrical junction box - Google Patents

Description

  The present invention mainly relates to an electrical junction box mounted on an automobile.

2. Description of the Related Art As an electrical connection box disposed in an automobile engine room or the like, there is known an electrical connection box in which a circuit component on which an electronic component such as a semiconductor switching element is mounted is accommodated in a waterproof casing (for example, Patent Document 1). reference). In such an electrical junction box, for example, a heat radiating member is attached to the lower surface side of the circuit component, and the heat generated from the electronic component is exposed by exposing the heat radiating member from the heat radiating opening provided on the lower surface side of the casing. I try to escape outside.
JP 2003-164039 A

  In the electrical junction box as described above, as a measure to further improve the heat dissipation performance, the heat transfer lug extending outward from the heat dissipation member is attached to the body panel, so that the heat of the heat dissipation member is directly transmitted to the body panel. Configuration is being considered. However, when such a configuration is adopted, an insertion hole for inserting the heat transfer protrusion on the side surface of the casing will be provided, and then the gap between the outer peripheral surface of the heat transfer protrusion and the inner peripheral surface of the insertion hole Therefore, there is a problem that water easily enters the casing.

  The present invention has been completed based on the above circumstances, and an object thereof is to improve waterproofness.

As means for achieving the above object, an electrical junction box according to the invention of claim 1 is attached to a circuit structure, a casing that accommodates the circuit structure and has an insertion hole, and the circuit structure. And a heat radiating member having a heat transfer protrusion extending from the inside to the outside of the casing through the insertion hole, and a rubber made to seal between the heat transfer protrusion and the hole edge of the insertion hole The casing is composed of a pair of case members that can be assembled to each other, the insertion hole is formed between the case members, and the seal member is sandwiched between the case members. Further, in the casing, a pair of cover members for accommodating the circuit component is provided, and a body side insertion hole for inserting the heat transfer protrusion between the cover members is formed. While being, characterized in was configured to the sealing member is sandwiched between the two cover members.

  According to a second aspect of the present invention, the seal member according to the first aspect is characterized in that the seal member is provided in an annular shape over the entire outer peripheral surface of the heat transfer protrusion in the insertion hole.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the seal member includes a positioning protrusion, and the heat transfer protrusion has a positioning recess with which the positioning protrusion is engaged. It has features where it is provided.

According to a fourth aspect of the present invention, there is provided a device according to any one of the first to third aspects, wherein the heat transfer projection piece also serves as an attachment portion for a vehicle body of an automobile.

<Invention of Claim 1>
Since the space between the outer peripheral surface of the heat transfer protrusion extending from the heat radiating member and the inner peripheral surface of the insertion hole provided in the casing is sealed by the seal member, the waterproof property can be improved.
In addition, since the insertion hole through which the heat transfer protrusion is inserted is formed between the pair of case members, the seal member is not pushed into the insertion hole when assembling, but the seal member is inserted between the case members. Assembling can be carried out so that the assembling work is easy. In addition, since the seal member is sandwiched between the case members, the adhesion of the seal member to the heat dissipation member is improved, so that the waterproof property can be further improved.
In addition, since the main body side insertion hole for inserting the heat transfer protrusion between the two cover members is provided, the seal member is sandwiched between the two cover members instead of being pushed into the main body side insertion hole during assembly. Thus, the assembly work is easy. Further, since the seal member is sandwiched between the cover members, the adhesion of the seal member to the heat radiating member is improved, so that the waterproof property can be further improved.

<Invention of Claim 2>
Since the seal member is provided in an annular shape over the entire circumference of the outer peripheral surface of the heat transfer protrusion, the waterproof property can be further improved.

<Invention of Claim 3>
Since the positioning protrusion of the seal member is engaged with the positioning recess of the heat transfer protrusion, the positional displacement of the sealing member is prevented, so that it is possible to prevent a decrease in waterproofness due to the positional displacement of the sealing member. In addition, since the seal member is positioned at the correct position during assembly, the work can be performed smoothly. Since the displacement of the seal member is prevented, the waterproof property can be further improved.

<Invention of Claim 4 >
Since the heat transfer protrusion of the heat radiating member also serves as an attachment part for attaching the electric junction box to the vehicle body of the automobile, the structure of the electric junction box can be simplified, and the electric junction box can be made more compact.

<Embodiment 1>
Next, Embodiment 1 of the present invention will be described with reference to FIGS.
The electric connection box 1 of this embodiment is mounted in an engine room (not shown) of an automobile, and as shown in FIG. 1, the connection box main body 2 is accommodated in a casing 3 (only a part is shown). . In the following description, the left side of FIG.

  The junction box body 2 has a configuration in which a wiring board (not shown) and a control circuit board 5 (corresponding to the “circuit structure” of the present invention) are arranged side by side in a body case 4. The wiring board is formed by laminating a plurality of wiring boards in which a plurality of bus bars are arranged along the insulating board. As shown in FIGS. 1 and 2, the main body case 4 includes a synthetic resin main body upper surface cover 4A and a synthetic resin main body lower surface cover 4B, both of which cover the wiring board and the control. The circuit boards 5 are assembled together so as to be wrapped from above and below (both the main body upper surface cover 4A and the main body lower surface cover 4B correspond to the “cover member” of the present invention). Further, the main body upper surface cover 4A is provided with a replacement part mounting portion 7 at a position corresponding to the wiring board, to which a relay or a fuse (not shown) connected to the wiring board is detachably mounted.

  As shown in FIGS. 1 and 3, the control circuit board 5 is configured by forming a control circuit on one surface of the circuit board 8 by printed wiring means and mounting electronic components such as a relay 9 and an FET 10 on the control circuit board 5. A predetermined one of the plurality of bus bars 11 is placed on the surface opposite to the component mounting surface in a state of being electrically connected to the control circuit. In addition, predetermined ones of the bus bars 11 are connected to the terminals of the relay 9 and the FET 10 to constitute a power circuit. The bus bar 11 is integrally attached to the circuit board 8 via a thin adhesive sheet (not shown) having insulating properties. In addition, a frame body 12 that surrounds the control circuit board 5 over the entire circumference is disposed around the control circuit board 5.

  Further, on the lower surface of the bus bar 11, a heat radiating plate 13 (corresponding to the “heat radiating member” of the present invention) for absorbing heat generated from electronic components such as the relay 9 and the FET 10 and escaping to the outside is provided with an insulating adhesive. It is bonded via a layer 14 (see FIG. 3). The heat radiating plate 13 is integrally formed of a metal plate such as aluminum having a high thermal conductivity. The heat radiating plate 13 includes a substantially rectangular heat radiating plate main body 15 that covers the lower surface of the control circuit board 5, and a heat transfer protrusion 16 that extends forward from the front end of the heat radiating plate main body 15. The main body lower surface cover 4B is provided with an opening 17 that exposes the lower surface of the heat sink main body 15 (more specifically, the central portion excluding the peripheral edge), and the heat sink main body 15 closes the opening 17. Are arranged as follows. Further, on the front surface of the main body case 4, a main body side insertion hole 18 for inserting the heat transfer protrusion 16 is formed between the main body upper surface cover 4 </ b> A and the main body lower surface cover 4 </ b> B. In addition, between the main body upper surface cover 4A and the main body lower surface cover 4B, the periphery except for the portion where the main body side insertion hole 18 is present is closed with almost no gap.

  The heat transfer protrusions 16 extend horizontally from the front edge of the heat radiating plate main body 15 to the front, and extend from the front end of the extension 16A toward substantially downward (diagonally lower front). And a mounting portion 16C extending from the lower end of the connecting portion 16B substantially forward (obliquely lower front). As shown in FIGS. 5 and 7, the extension portion 16 </ b> A is formed with a pair of positioning recesses 20 for positioning a seal member 27 described later on both sides in the width direction. The width dimension of the attachment portion 16C is smaller than the width dimension of the extension portion 16A, and the connecting portion 16B has an upper end side that is the width dimension of the extension portion 16A and a lower end side that is the width dimension of the attachment portion 16C. It has a tapered shape. Further, the mounting portion 16C is provided with a bolt insertion groove 22 through which the shaft portion 21A (see FIG. 3) of the bolt 21 can be inserted, opened in the center of the width dimension in the front-rear direction and on the rear end side. ing. Further, a bolt entry hole 23 through which the head 21 </ b> B of the bolt 21 can pass is formed in the connecting portion 16 </ b> B continuously to the bolt insertion groove 22. Reinforcing ribs 24 are provided on both the left and right sides of the connecting portion 16B and the mounting portion 16C with the bolt insertion groove 22 and the bolt entry hole 23 interposed therebetween. Each reinforcing rib 24 is formed by knocking out a metal plate constituting the heat transfer protrusion 16 to the surface side thereof (that is, the front surface side of the connecting portion 16B and the upper surface side of the mounting portion 16C) in a circular arc shape.

  As shown in FIGS. 4, 5, and 7, the seal member 27 is integrally formed of a rubber material having appropriate elasticity such as EPDM (ethylene / propylene rubber). The seal member 27 has an elongated shape on the left and right as a whole, and includes a substantially plate-like plate-like portion 28 that is flat in the front-rear direction and an overhanging portion 29 that projects to the rear side of the plate-like portion 28. Further, a through hole 30 penetrating in the front-rear direction is formed in the seal member 27 from the front surface of the plate-shaped portion 28 to the rear surface of the overhang portion 29. By inserting the extended portion 16A of the heat transfer protrusion 16 through the through hole 30, the seal member 27 is transferred in a state where the inner peripheral surface of the through hole 30 is elastically in close contact with the outer peripheral surface of the extended portion 16A. The heat projection piece 16 is attached. Further, positioning protrusions 31 that can be engaged with the positioning recess 20 are provided on both the left and right sides of the inner peripheral surface of the through hole 30 so as to protrude inward.

  Further, on the upper surface and the lower surface of the overhang portion 29, there are provided protruding protrusions 32A and 32B that extend in the left-right direction at the rear end positions. As shown in FIG. 3, the overhanging portion 29 is sandwiched between the main body upper surface cover 4 </ b> A and the main body lower surface cover 4 </ b> B while being elastically compressed and deformed in the vertical direction by the hole edge portions of the main body side insertion holes 18. The upper surface side retaining protrusion 32A engages with the rear surface of the main body upper surface cover 4A and the lower surface side retaining protrusion 32B engages with the rear surface of the main body lower surface cover 4B, thereby preventing the seal member 27 from coming off. Further, the plate-like portion 28 of the seal member 27 has a lip portion 33 projecting from the lower surface to both the left and right side surfaces. Further, a stepped portion 34 that is recessed in a stepped shape is formed on the upper front surface of the plate-like portion 28 over the entire width.

  As shown in FIG. 3, the casing 3 includes a synthetic resin upper case 3 </ b> A covering the upper surface side of the connection box body 2, and a synthetic resin lower case 3 </ b> B covering the lower surface side of the connection box body 2. (Both upper case 3A and lower case 3B correspond to the “case member” of the present invention). The lower case 3B is provided with a heat dissipation opening 36 that is opened up and down at a position corresponding to the opening 17 of the main body lower surface cover 4B, and the heat sink main body 15 opens the opening above the heat dissipation opening 36. It is arranged to block. In addition, an insertion hole 37 for inserting the heat transfer protrusion 16 of the heat radiating plate 13 between the upper case 3A and the lower case 3B is provided on the front surface of the casing 3. In addition, between the upper case 3 </ b> A and the lower case 3 </ b> B, the periphery except for the portion where the insertion hole 37 is provided is closed with almost no gap. An accommodation groove 38 for accommodating the substantially lower half portion of the plate-like portion 28 is provided at the hole edge portion of the insertion hole 37 in the lower case 3B so as to open upward, and the lip portion 33 of the plate-like portion 28 is accommodated therein. The groove 38 is in elastic contact with the bottom surface and the left and right inner surfaces. Further, a step edge 39 having a shape matching the front surface of the step 34 is provided at the hole edge of the insertion hole 37 in the upper case 3A. The seal member 27 is held in a state where the upper portion of the plate-like portion 28 is pressed to the lower side (the heat transfer protrusion 16 side) by the step edge portion 39.

  When the electrical connection box 1 is assembled, first, the heat transfer protrusion 16 of the heat sink 13 attached to the control circuit board 5 is inserted into the through hole 30 of the seal member 27, and the positioning protrusion 31 of the through hole 30. Is engaged with the positioning recess 20 of the heat transfer protrusion 16 to position the seal member 27. Subsequently, the main body upper surface cover 4A and the main body lower surface cover 4B are assembled to each other so as to wrap the control circuit board 5 and the wiring board (not shown) from above and below. At this time, the protruding portion 29 of the seal member 27 is vertically sandwiched by the hole edges of the main body side insertion hole 18 in the main body upper surface cover 4A and the main body lower surface cover 4B. The junction box body 2 thus completed is then assembled to the upper part of the lower case 3B, and then the upper case 3A is assembled from the upper surface thereof. As a result, the seal member 27 is compressed vertically by the hole edges of the insertion holes 37 in the upper case 3A and the lower case 3B.

  The electrical junction box 1 is installed on a metal body panel 40 provided on the upper surface of a tire housing (not shown). When the electrical junction box 1 is installed, the head 21B of the bolt 21 attached in advance on the body panel 40 is advanced from the bolt entry hole 23 of the heat transfer protrusion 16 above the attachment portion 16C, and the shaft of the bolt 21 The portion 21A is inserted into the bolt insertion groove 22, and the mounting portion 16C is tightened with the bolt 21. Note that the lower case 3B of the casing 3 is integrally provided with a plurality of mounting portions (not shown), and the casing 3 is fixed by bolting the mounting portions to the body panel 40 in the same manner. In this state where the electrical junction box 1 is installed, the heat sink body 15 is opposed to the body panel 40 through the heat release opening 36 of the casing 3, so that the heat of the heat sink 13 is radiated to the body panel 40. It is absorbed there. Further, since the heat transfer protrusion 16 of the heat radiating plate 13 is directly fixed to the body panel 40, heat from the heat radiating plate main body 15 side is directly transmitted to the body panel 40 via the heat transfer protrusion 16 and absorbed there. The

  As described above, according to this embodiment, the seal member 27 seals between the outer peripheral surface of the heat transfer protrusion 16 extending from the heat radiating plate 13 and the inner peripheral surface of the insertion hole 37 provided in the casing 3. Therefore, waterproofness can be improved.

  Moreover, since the seal member 27 is provided in an annular shape over the entire outer peripheral surface of the heat transfer protrusion 16, the waterproof property can be further improved.

  In addition, since the positioning protrusion 31 of the seal member 27 is engaged with the positioning recess 20 of the heat transfer protrusion 16, the position of the seal member 27 is prevented from being displaced. Decline can be prevented. Further, since the seal member 27 is positioned at the correct position during assembly, the work can be performed smoothly.

  In addition, since the insertion hole 37 through which the heat transfer protrusion 16 is inserted is formed between the upper case 3A and the lower case 3B, the upper member is not pushed into the insertion hole when assembling. The sealing member 27 can be assembled between the case 3A and the lower case 3B so that the assembling work is easy. Further, since the seal member 27 is sandwiched between the upper case 3A and the lower case 3B, the adhesion of the seal member 27 to the heat radiating plate 13 is improved, so that the waterproof property can be further improved.

  In addition, since the heat transfer protrusion 16 of the heat radiating plate 13 also serves as an attachment portion for attaching the electric junction box 1 to the vehicle body, the structure of the electric junction box 1 can be simplified and the electric junction box 1 can be made more compact. It can be.

  Further, since the main body side insertion hole 18 through which the heat transfer protrusion 16 is inserted is provided between the main body upper surface cover 4A and the main body lower surface cover 4B, the seal member 27 is not pushed into the main body side insertion hole during assembly. However, the seal member 27 can be assembled between the main body upper surface cover 4A and the main body lower surface cover 4B, and the assembling work is easy. Further, since the seal member 27 is sandwiched between the main body upper surface cover 4A and the main body lower surface cover 4B, the adhesion of the seal member 27 to the heat radiating plate 13 is improved, so that the waterproof property can be further 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.
(1) Instead of the positioning protrusion 31 and the positioning recess 20 of the above embodiment, as shown in FIGS. 9 and 10, a positioning protrusion 42 that protrudes downward on the inner peripheral surface of the through hole 30 in the seal member 27 is provided. It is good also as a structure which provides and this positioning protrusion 42 is fitted in the positioning recessed part 43 penetrated up and down in the center part of the width direction in the extension part 16A of the heat-transfer protrusion 16. If comprised in this way, in the positioning protrusion 42, since the boundary surface of the sealing member 27 and the heat-transfer protrusion 16 meanders up and down, water will be transmitted from the outside along the boundary surface in the main body case 4 It is prevented from entering.
(2) In the above embodiment, the seal member is provided over the entire outer peripheral surface of the heat transfer protrusion. However, the seal member is provided only on a part of the outer peripheral surface of the heat transfer protrusion. Also good.

Side sectional view which shows the electrical junction box in one Embodiment of this invention Perspective view of the junction box body Partial enlarged sectional view of the electrical junction box Side view of seal member Partial enlarged plan view showing a state before the sealing member is mounted on the heat sink Partially enlarged plan view showing a state where the sealing member is mounted on the heat sink The perspective view which shows the state before attaching a sealing member to a heat sink. The perspective view which shows the state which mounted | wore the heat sink with the sealing member. The perspective view which shows the state before mounting | wearing a heat sink with a sealing member in other embodiment. Partial enlarged sectional view of the electrical junction box

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Electrical junction box 3 ... Casing 3A ... Upper case (case member)
3B ... Lower case (case member)
4A ... Top cover of main body (cover member)
4B ... Body bottom cover (cover member)
5 ... Control circuit board (circuit structure)
13 ... Radiating plate (heat radiating member)
16 ... Heat transfer protrusion 18 ... Main body side insertion holes 20, 43 ... Positioning recess 27 ... Seal members 31, 42 ... Positioning protrusion 37 ... Insertion hole

Claims (4)

A circuit construct;
A casing containing the circuit structure and having an insertion hole;
A heat dissipating member having a heat transfer protrusion attached to the circuit structure and extending from the inside of the casing through the insertion hole, and
A rubber seal member that seals between the heat transfer protrusion and a hole edge of the insertion hole;
Equipped with a,
The casing is composed of a pair of case members that can be assembled together, the insertion hole is formed between the case members, and the seal member is sandwiched between the case members,
Furthermore, a pair of cover members for housing the circuit component is provided in the casing, a body side insertion hole for inserting the heat transfer protrusion is formed between the cover members, and the seal member Is an electric junction box that is sandwiched between the cover members . The electrical junction box according to claim 1, wherein the seal member is provided in an annular shape over the entire circumference of the outer peripheral surface of the heat transfer protrusion in the insertion hole. The electrical connection according to claim 1, wherein the seal member includes a positioning protrusion, and the heat transfer protrusion includes a positioning recess with which the positioning protrusion is engaged. box. The electric junction box according to any one of claims 1 to 3 , wherein the heat transfer projection piece also serves as an attachment portion for a vehicle body of an automobile.

Images