JP4524667B2 - 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 engine room of an automobile or the like, there is known an electrical connection box in which a circuit structure on which electronic components such as a semiconductor switching element are mounted is accommodated in a synthetic resin casing (for example, patent document) 1). In such an electrical junction box, for example, a heat radiating member made of metal is attached to the lower surface side of the circuit structure, and the heat radiating member is exposed from an opening provided on the lower surface side of the casing, thereby generating heat generated from the electronic component. To escape to the outside.
JP 2003-164039 A

  In the electrical junction box as described above, as a measure for further improving the heat dissipation performance, the heat transfer protrusions extended from the heat dissipation member to the outside of the casing are fixed to the body panel by bolting, so that the heat of the heat dissipation member is increased. A configuration is being studied that conveys the information directly to the body panel. The casing has a plurality of integrally formed mounting portions in addition to the heat transfer protrusions, and is fixed by bolting each mounting portion to the body panel. Such a configuration simplifies the configuration of the electrical junction box because the heat transfer protrusion serves both as a function of heat dissipation and as a function of fixing the casing. However, since the casing made of synthetic resin expands and contracts slightly when subjected to vibration of the vehicle body, a large load is applied to the metal heat transfer protrusion that is firmly fixed to the body panel. In particular, when the heat transfer protrusion has a bent portion, a large load is applied to the portion, which may cause deformation.

  This invention is completed based on the above situations, Comprising: It aims at improving the intensity | strength of a heat radiating member.

As means for achieving the above object, an electrical junction box according to the invention of claim 1 is attached to the circuit structure, a casing for housing the circuit structure, the circuit structure, and the casing. And a heat dissipating member having a heat transfer protrusion that extends outward and is fixed to the vehicle body . The connecting portion has a bolt entry hole through which a bolt head can pass, and the mounting portion is connected to the bolt entry hole and can be inserted through the bolt shaft portion. Furthermore, the heat transfer protrusions extend on both sides of the bolt entry hole and the bolt shaft insertion groove from the connection part to the attachment part via the bent part and project in the plate thickness direction. Toko Ru comprising a reinforcing projections forming the Jo To have the feature.

<Invention of Claim 1>
By forming the reinforcing protrusion at the bent portion of the heat transfer protrusion, the strength is improved, and deformation due to vibration of the vehicle body can be prevented.

Moreover, since the reinforcement protrusion is extended along the extending direction of the heat transfer protrusion, the strength of the heat transfer protrusion other than the bent portion is improved.

Further , although a large load is applied around the bolt shaft insertion hole, deformation of the heat transfer protrusion can be prevented by providing reinforcing protrusions on both sides so as to sandwich the bolt shaft insertion hole.

<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 to each other so as to be wrapped from above and below. 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 4 </ b> A and the main body lower surface cover 4 </ b> B, the periphery except for the portion where the main body side insertion hole 18 is provided is closed with almost no gap.

  As shown in FIGS. 3 and 4, the heat transfer protrusion 16 includes an extending portion 16 </ b> A that extends horizontally from the front edge portion of the heat radiating plate main body portion 15 and a substantially lower portion from the front end of the extending portion 16 </ b> A. A connecting portion 16B extending toward (slant lower front) and a mounting portion 16C extending from the lower end of this connecting portion 16B substantially forward (slant lower front) are provided. The portion 16C is bent so as to form a substantially L shape when viewed from the side through the bent portion 19 (more accurately, it forms a slightly larger angle than a right angle). 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 has a bolt insertion groove 22 (corresponding to the “bolt shaft insertion hole” of the present invention) through which the shaft portion 21A (see FIG. 3) of the bolt 21 can be inserted in the center of the width dimension in the front-rear direction. Along the opening and the rear end side. Furthermore, 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. The heat transfer protrusion 16 is provided with reinforcing protrusions 24 on both the left and right sides with the bolt insertion groove 22 and the bolt entry hole 23 interposed therebetween. Each reinforcing protrusion 24 extends in parallel along the extending direction of the heat transfer protrusion 16, and is provided in a region extending from the connecting portion 16 </ b> B to the attachment portion 16 </ b> C via the bent portion 19. Further, as shown in FIG. 5, each reinforcing protrusion 24 has a metal plate constituting the heat transfer protrusion 16 on its surface side (that is, in the plate thickness direction, on the front surface side of the connecting portion 16 </ b> B, the mounting portion 16 </ b> C). It is formed by knocking out in a circular arc shape so as to be convex to the upper surface side).

  As shown in FIGS. 3 and 4, the seal member 27 is integrally formed of a rubber material having an 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 protrudes 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, 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. Yes. The lower case 3B is integrally provided with a plurality of mounting portions (not shown) for fixing with bolts. Further, the lower case 3B is provided with a heat radiation opening 36 that is opened up and down at a position corresponding to the opening 17 of the main body lower surface cover 4B. The heat radiation plate main body 15 is located above the heat radiation opening 36. It arrange | positions so that opening may be obstruct | occluded. 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 elastically in 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 assembling the electrical junction box 1, 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 heat transfer protrusion 16 is extended. The heat transfer protrusion 16 is mounted on the outer periphery of the portion 16A. 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. Subsequently, each attachment portion of the lower case 3 </ b> B is bolted to the body panel 40, so that the electrical junction box 1 is fixed to the body panel 40 by each attachment portion and the heat transfer protrusion 16. 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

According to the present embodiment, since the reinforcing protrusion 24 is formed in the bent portion 19 of the heat transfer protrusion 16, the strength of the heat transfer protrusion 16 is improved and deformation due to vibration of the vehicle body can be prevented.
Moreover, since the reinforcement protrusion 24 is extended along the extending direction of the heat transfer protrusion 16, the strength of the heat transfer protrusion 16 other than the bent portion 19 is also improved.
Furthermore, although a large load is applied around the bolt insertion groove 22, the deformation of the heat transfer protrusion 16 can be prevented by providing the reinforcing protrusions 24 on both sides so as to sandwich the bolt insertion groove 22.

<Embodiment 2>
Next, a second embodiment of the present invention will be described with reference to FIGS.
A pair of left and right reinforcing protrusions 50 of the present embodiment are provided on the bent portion 19 of the heat transfer protrusion 16 with the bolt entry hole 23 interposed therebetween. The reinforcing protrusion 50 is locally provided only in the vicinity of the bent portion 19, and the cross section has a mountain shape.

<Embodiment 3>
Next, a third embodiment of the present invention will be described with reference to FIGS.
A pair of reinforcing protrusions 51 of the present embodiment are provided on both the left and right sides of the heat transfer protrusion 16 with the bolt insertion groove 22 and the bolt entry hole 23 in between. Each reinforcing protrusion 51 is provided in a region extending from the connecting portion 16B to the attaching portion 16C via the bent portion 19, and is provided along the left and right side edges of the connecting portion 16B and the attaching portion 16C. That is, the portion struck out as the reinforcing protrusion 51 is applied to the side edge of the heat transfer protrusion 16, and the region where the reinforcing protrusion 51 is provided is reduced accordingly. For this reason, in the attachment part 16C of the heat transfer protrusion 16, the reinforcement protrusion 51 is provided in comparison with the case where the reinforcement protrusion 51 is arranged on the inner side so as not to cover the side edge of the heat transfer protrusion 16. The area of the unexposed area is large. Accordingly, when the heat transfer protrusion 16 is fixed on the body panel 40, the load applied to the mounting portion 16C is dispersed by the amount of contact with the body panel 40, so that the heat transfer protrusion 16 Deformation is prevented.

<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) The shape of the reinforcing protrusion is not limited to that described in each of the above embodiments, and may be a flat cross-sectional shape such as the reinforcing protrusion 52 shown in FIG.

Side sectional view which shows the electrical junction box in Embodiment 1 of this invention Perspective view of the junction box body Partial enlarged sectional view of the electrical junction box Partial enlarged plan view of heat sink Partial enlarged sectional view of heat sink The partial expansion perspective view which shows the heat-transfer protrusion of Embodiment 2. Partial enlarged sectional view of heat transfer protrusion The partial enlarged plan view which shows the heat-transfer protrusion of Embodiment 3 Side view of heat transfer protrusion Partial expanded sectional view which shows the heat-transfer protrusion of other embodiment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Electrical junction box 3 ... Casing 5 ... Control circuit board (circuit structure)
13 ... Radiating plate (heat radiating member)
16 ... Heat transfer protrusion 19 ... Bending portion 21A ... Bolt shaft 22 ... Bolt insertion groove (bolt shaft insertion hole)
24, 50, 51, 52 ... Reinforcing projection 40 ... Body panel (vehicle body)

Claims (1)

A circuit construct;
A casing for housing the circuit component;
A heat dissipating member having a heat transfer protrusion attached to the circuit structure and extending to the outside of the casing and fixed to the vehicle body side,
The heat transfer protrusion is a structure in which a connecting portion and a mounting portion extending to the tip side thereof are bent at a bent portion,
The connecting portion has a bolt entry hole through which a bolt head can pass,
The mounting portion has a bolt shaft insertion groove that is continuous with the bolt entry hole and can be inserted through the shaft portion of the bolt.
Furthermore, the heat transfer protrusion extends from the connecting portion to the attachment portion via the bent portion on both sides of the bolt entry hole and the bolt shaft insertion groove, and is reinforced in a convex shape in the plate thickness direction. electrical connection box, characterized in that Ru provided with a protrusion.

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