JP2006304517A - Electrical junction box - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrical junction box with improved waterproofness.
An electrical system in which a bus bar 19 is led to the outside from a bus bar outlet 21 along the inner wall surface of a frame body 14 and filled with a sealing material 35 so that a circuit board 11 is buried in the casing 12. In the connection box 10, resin wrapping gaps 38 </ b> A and 38 </ b> B are formed between the bus bars 19 along the inner wall surface of the frame body 14 and the inner wall surface of the frame body 14. A stop material 35 surrounds the entire circumference of the bus bar 19. Even when the moisture enters the bus bar 19 from the portion led out of the casing 12 of the bus bar 19, the entire circumference of the bus bar 19 is surrounded by the sealing material 35. , 38B can be prevented from entering the circuit board 11 side. Thereby, the waterproofness of the electrical junction box 10 can be improved.
[Selection] Figure 4

Description

  The present invention relates to an electrical junction box in which a circuit board is accommodated.

Conventionally, the thing of patent document 1 is known as an electrical junction box for vehicles. In this device, a circuit board having a bus bar along an insulating substrate is accommodated in a container-like casing, and the bus bar is led out from a bus bar outlet formed in the casing along the bottom surface of the casing. The casing is filled with a liquid potting agent (sealing material), and then the sealing material is solidified to cover the circuit board with the sealing material. In this electrical junction box, the end of the bus bar is extended to the outside of the circuit board, and then introduced into a connector hood provided in the casing to serve as a male terminal for connection to the mating connector. ing.
JP 2003-164039 A

  However, according to the above configuration, the bus bar is disposed along the bottom surface of the casing. Therefore, when the casing is filled with the sealing material, the surface of the bus bar facing the bottom surface of the casing has the sealing material. You can't wrap around. For this reason, for example, when a force in the direction of peeling the bus bar from the casing is applied to the bus bar, such as when the mating connector is inserted or removed, a gap may be formed between the bus bar and the bottom surface of the casing. . Then, at the time of car wash or rain, moisture is transferred from the end of the bus bar led out of the casing to the bus bar and enters the casing, and the bus bar is removed from the gap formed between the bus bar and the bottom of the casing. There is a concern that the moisture will reach the circuit board as a result and the conductive paths formed on the circuit board will be short-circuited.

  The present invention has been completed based on the above circumstances, and an object thereof is to provide an electrical junction box with improved waterproofness.

  As means for achieving the above object, the invention of claim 1 is characterized in that a circuit board formed by arranging a bus bar along an insulating board is accommodated in a container-like casing, and the bus bar is mounted on the casing. In an electrical junction box filled with a sealing material so as to bury the circuit board in the casing, it is led out to the outside from a bus bar outlet formed in the casing along the inner wall surface. A portion extending along the inner wall surface of the casing extending from the circuit board is partially formed with a resin wrapping gap between the inner wall surface of the casing, and the sealing material is formed in the resin wrapping gap in the bus bar. It is characterized by being filled around the entire circumference.

  A second aspect of the invention is characterized in that, in the first aspect of the invention, the resin wraparound gap is formed by forming a recess in an inner wall surface of the casing.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, an electrical component is removably attached to a front end portion of the bus bar protruding from the casing. It is along the surface orthogonal to the insertion / extraction direction of the said electrical component among the inner wall surfaces of a casing, It is characterized by the above-mentioned.

<Invention of Claim 1>
According to the first aspect of the present invention, the entire circumference of the bus bar is surrounded by the sealing material in the resin wrapping gap even when moisture enters the casing from the portion of the bus bar led to the outside of the casing. Therefore, it is possible to prevent moisture from entering the circuit board side through the resin wrap-around gap. Thereby, the waterproofness of an electrical junction box can be improved.

<Invention of Claim 2>
According to the invention of claim 2, the waterproofness of the electrical junction box can be improved by a simple method of forming a recess in the inner wall surface of the casing and forming a resin wraparound gap by the recess.

<Invention of Claim 3>
According to the invention of claim 3, when inserting / extracting the electrical component, even if a force in the insertion / extraction direction of the electrical component acts on the bus bar due to the frictional force acting between the tip of the bus bar and the electrical component, The bus bar is firmly supported by a surface of the inner wall surface of the casing that is orthogonal to the insertion / extraction direction of the electrical component. As a result, it is possible to prevent the bus bar from being deformed even if a force is applied to the bus bar when the electrical component is inserted or removed.

  An embodiment of the present invention will be described with reference to FIGS. The present embodiment is an electric junction box 10 for a vehicle, and a circuit board 11 is accommodated in a flat casing 12. The casing 12 includes a heat dissipation plate 13 that covers the lower side of the circuit board 11, a frame body 14 that surrounds the side of the circuit board 11, and a cover 15 that covers the upper side of the circuit board 11.

  The heat sink 13 is made of metal and has a substantially rectangular shape. The heat radiating plate 13 is bonded to the lower surface side of the circuit board 11 with an adhesive (not shown) so as to dissipate heat generated from the circuit board 11 to the outside of the electrical connection box 10.

  The frame body 14 is made of synthetic resin, and is bonded to the upper surface of the heat radiating plate 13 with an adhesive (not shown) and is screwed from the lower surface side of the heat radiating plate 13. As shown in FIG. 6, the frame body 14 has an open top and bottom shape, surrounds the periphery of the circuit board 11 without a break, and accommodates the circuit board 11 in the opening. .

  The cover 15 is made of a synthetic resin, has a shallow container shape, and is attached so as to cover the circuit board 11 from above the frame body 14. The lock protrusion 16 is formed at a predetermined position on the outer surface of the side wall 36 of the frame body 14 described above, while the lock receiving portion 40 is provided at a position corresponding to the lock protrusion 16 on the side wall 36 of the cover 15. It is formed (see FIG. 2). The cover 15 and the frame body 14 are fixed by elastically engaging the lock protrusion 16 of the frame body 14 and the lock receiving portion 40 of the cover 15.

  The circuit board 11 has a control circuit formed on the surface of an insulating substrate 17 having a substantially rectangular shape by printed wiring means, and an electronic component 18 such as a switching element is mounted on the surface side so as to be connected to the control circuit. ing. On the other hand, on the back surface side of the insulating substrate 17, a plurality of bus bars 19, in which a predetermined power circuit is formed by punching and forming a metal plate, are electrically connected to the electronic component 18, and the insulating substrate Along the back surface of 17, an adhesive adhesive sheet (not shown) is adhered.

  The end of the bus bar 19 that extends to the right of the circuit board 11 in FIG. 4 is bent at a right angle twice on the circuit board 11 side, bent into a crank shape, and protrudes to the right in FIG. (A portion bent in the vertical direction in the figure is a bent portion 20A). The bent portion 20A is led out of the casing 12 through a bus bar outlet 21 formed between the cover 15 and the frame 14, and then introduced into a fuse block 22 described later. A portion of the bent portion 20 </ b> A led out of the casing 12 is sandwiched between an outer surface of the bottom wall of the fuse block 22 and a support plate 23 formed on the outer wall surface of the cover 15. As a result, when a fuse 24 described later (corresponding to an electrical component according to the present invention) is inserted into or extracted from the fuse block 22, force in the insertion / extraction direction of the fuse 24 acts on the bending portion 20A. Since the bent portion 20A is firmly supported by the outer surface of the bottom wall, the bent portion 20A can be prevented from being deformed.

  The end of the bus bar 19 that extends to the left of the circuit board 11 in FIG. 5 is bent at a right angle twice on the circuit board 11 side, bent into a crank shape, and protrudes to the left in FIG. (A portion bent in the vertical direction in the figure is a bent portion 20B). This end is introduced into a connector block 25 described later. A portion of the bent portion 20 </ b> B above the frame body 14 is sandwiched between the outer surface of the bottom wall of the connector block 25 and the support plate 23 formed on the inner wall surface of the cover 15. Thus, when a mating connector 26 (corresponding to an electrical component according to the present invention) described later is inserted into and extracted from the connector block 25, a force in the mating / unplugging direction of the mating connector 26 acts on the bent portion 20B. And since the bending part 20B is firmly supported by the outer surface of the bottom wall of the connector block 25, it can prevent that the bending part 20B deform | transforms.

  A fuse block 22 is attached above the frame body 14 at a position near the right end of the frame body 14 in FIGS. 4 and 5. As shown in FIG. 3, the fuse block 22 is substantially U-shaped, and includes a substantially rectangular parallelepiped main body 22A and two attachment portions 22B extending in the same direction from both ends of the main body 22A. As shown in FIGS. 1 and 2, the fuse block 22 and the frame body 14 are attached by screwing the attachment portion 22 </ b> B of the fuse block 22 and the frame body 14. The fuse block 22 is provided with a fuse mounting portion 27 that opens to the right in FIG. 4, and the fuse 24 is attached to the fuse mounting portion 27 so that it can be inserted and removed from the left and right directions in FIG. 4. It has become. As shown in FIG. 1, the fuse mounting portion 27 is divided into two locations, a right half side in the width direction and a left half side, on the side surface on the right front side of the electrical junction box 10 in FIG. The part 27 is arranged side by side. As shown in FIG. 4, the end portion of the bus bar 19 is arranged on the fuse mounting portion 27 with one end protruding into the opening and the other end penetrating the back wall. A relay terminal 28, which will be described later, is disposed in the fuse mounting portion 27 with one end protruding into the opening. The end of the bus bar 19 and the relay terminal 28 are mounted on the back wall of the fuse mounting portion 27 side by side in two upper and lower stages in FIG. 4, and the end of the bus bar 19 is disposed on the lower side. The relay terminal 28 is disposed on the upper stage side. The end portion of the bus bar 19 and the relay terminal 28 are connected by a fuse 24 inserted in the fuse mounting portion 27.

  4 and 5, a relay connector 29 is fitted to the fuse block 22 (see FIG. 4) and attached to the fuse block 22 by screwing from the upper surface side to the left side of the fuse block 22. (See FIGS. 1 and 2). The relay connector 29 is provided with a connector hood 30A that opens to the left in FIG. In the connector hood 30A, the relay terminal 28 is arranged with one end protruding into the opening and the other end penetrating the back wall.

  As shown in FIG. 3, the relay terminal 28 is formed by punching a metal plate and bending it into a substantially crank shape. As shown in FIGS. 4 and 5, the relay terminal 28 has a left end facing the connector hood 30 </ b> A of the relay connector 29 (see FIG. 5) and a right end facing the fuse mounting portion 27 of the fuse block 22. (See FIG. 4). A mating connector (not shown) is fitted to the connector hood 30 </ b> A so that it can be inserted and removed from the left and right directions in FIG. 5 and connected to the relay terminal 28.

  As shown in FIG. 2, connector blocks 25, 25 are disposed at both ends of the left front side of FIG. 2 in the electrical connection box 10, and a PCB connector 31 is interposed between the connector blocks 25, 25. It is arranged.

  A connector block 25 is disposed above the frame body 14 at a position near the left end of the frame body 14 in FIG. As shown in FIG. 3, the connector block 25 is screwed to the frame body 14. The connector block 25 includes a connector hood 30B that opens to the left in FIG. 5. In the connector hood 30B, one end of the bus bar 19 protrudes into the opening and the other end penetrates the back wall. It is arranged in the state. The mating connector 26 is fitted to the connector hood 30 </ b> B so that it can be inserted and removed from the left and right directions in FIG. 5, and an in-vehicle electrical component (not shown) and the end of the bus bar 19 are connected by the wire harness 32.

  A PCB connector 31 is disposed above the frame body 14 at a position near the left end of the frame body 14 in FIG. As shown in FIG. 3, the PCB connector 31 is screwed to the frame body 14. The PCB connector 31 includes a connector hood 30C that is opened to the left in FIG. 4. In the connector hood 30C, one end of the terminal fitting 33 projects into the opening and the other end penetrates the back wall. It is arranged. The side of the terminal fitting 33 that protrudes from the rear wall to the outside of the connector hood 30 </ b> C is bent downward in FIG. 4 and is connected to the control circuit of the circuit board 11 while penetrating the circuit board 11. The mating connector 26 is fitted into the connector hood 30C of the PCB connector 31 so as to be insertable / removable from the left-right direction in FIG. 4, and the side of the terminal fitting 33 protruding into the connector hood 30C of the PCB connector 31 is illustrated. In-vehicle electrical components that are not connected are connected by the wire harness 32.

  In order to prevent the heat sink 13 from interfering with the end of the terminal fitting 33 of the PCB connector 31 on the side penetrating the circuit board 11 and the heat sink 13, the heat sink 13 has a position corresponding to the terminal fitting 33. A relief recess 34 is formed by retracting downward in FIGS.

  As shown in FIGS. 4 and 5, a sealing material 35 is filled in a region surrounded by the frame body 14 and the heat radiating plate 13. The sealing material 35 is filled so that the circuit board 11 described above is buried, and is also filled in the relief recess 34 described above. Thereby, the waterproofness and insulation of the electrical junction box 10 can be improved. As the sealing material 35, for example, an epoxy resin, a urethane resin, or a silicone resin, for example, a material that can ensure insulation and waterproofness of the electrical connection box by burying and sealing the circuit board 11. Any material can be used.

  Now, the right side surface of the bent portion 20A on the right side in FIG. 4 of the bus bar 19 is disposed along the inner wall surface of the side wall 36A of the frame body 14 located on the right side in FIG. As described above, since the fuse 24 is attached to the fuse block 22 so that it can be inserted and removed from the left and right direction in FIG. 4, the inner wall surface of the side wall 36A of the frame body 14 located on the right side in FIG. The surface is perpendicular to the insertion / extraction direction of the fuse 24.

  On the lower side of the inner wall surface of the side wall 36A, as shown in FIG. 4, a recess 37A is formed by retracting to the right in FIG. A space between the inner wall surface of the concave portion 37 and the right side surface of the bent portion 20A is a resin wrapping gap 38A, and the entire circumference of the bus bar 19 is surrounded by the sealing material 35 in the resin wrapping gap 38A. As shown in FIGS. 3 and 7, the resin wrapping gap 38 </ b> A is formed over a region where the bent portion 20 </ b> A is disposed.

  A plurality of bus bars 19 are arranged at a predetermined pitch in a direction penetrating the paper surface in FIG. As shown in FIG. 7, a plurality of groove portions 39 for accommodating the bent portion 20A are formed on the inner wall surface of the side wall 36A disposed along the bent portion 20A of the frame body 14 (FIGS. 6 and 6). 7), the positioning of the bus bar 19 can be facilitated by accommodating the bent portion 20A in the groove 39. The pitch between the groove portions 39 is set to substantially coincide with the pitch between the bus bars 19.

  Further, the left side surface of the left bent portion 20B in FIG. 5 of the bus bar 19 is arranged along the inner wall surface of the side wall 36B of the frame body 14 located on the left side in FIG. As described above, the mating connector 26 is attached to the connector block 25 so that it can be inserted and removed from the left-right direction in FIG. 5, so that the inner side wall 36B of the frame 14 located on the left side in FIG. The wall surface is a surface perpendicular to the insertion / extraction direction of the mating connector 26.

  On the lower side of the inner wall surface of the side wall 36B, as shown in FIG. 5, a recess 37B is formed by retracting leftward in FIG. A space between the inner wall surface of the concave portion 37B and the left side surface of the bent portion 20B is a resin wrapping gap 38B, and the entire circumference of the bus bar 19 is surrounded by the sealing material 35 in the resin wrapping gap 38B. As shown in FIGS. 3 and 8, the resin wrapping gap 38 </ b> B is formed over a region where the bent portion 20 </ b> B is disposed.

  Further, the left side wall 36B in FIG. 5 of the frame body 14 has a plurality of groove portions 39 at substantially the same pitch as the bus bars 19 arranged side by side, as in the case of the right side wall 36A described above. The bus bar 19 can be easily positioned by accommodating the bent portion 20B in the groove 39 (see FIGS. 6 and 8).

  Then, the effect | action and effect of this embodiment are demonstrated. First, the liquid sealing material 35 is injected into a region surrounded by the heat radiating plate 13 and the frame body 14. Since the circuit board 11 is accommodated in this region as described above, the sealing material 35 spreads along the circuit board 11. When the sealing material 35 reaches the escape recess 34 of the heat radiating plate 13, the sealing material 35 flows into the escape recess 34 from a gap between adjacent bus bars 19. The sealing material 35 flows in while extruding the air in the escape recess 34, and eventually the escape recess 34 is filled with the sealing material 35. Then, the terminal fitting 33 of the PCB connector 31 is surrounded by the sealing material 35 over the entire circumference, and insulation between the terminal fittings 33 is achieved.

  Subsequently, when the sealing material 35 is injected and the inside of the escape recess 34 is filled with the sealing material 35, the liquid level of the sealing material 35 gradually rises in the region surrounded by the frame body 14, and eventually. The circuit board 11 is buried in the sealing material 35. At this time, since the concave portions 37A and 37B are formed in the side walls 36A and 36B of the frame body 14 to form the resin surrounding cavities 38A and 38B, the sealing material 35 flows into the concave portions 37A and 37B. A sealing material 35 wraps between the bent portions 20 </ b> A and 20 </ b> B and the inner wall surface of the side wall 36 of the frame body 14. As a result, the entire circumference of the bent portions 20 </ b> A and 20 </ b> B can be surrounded by the sealing material 35.

  Further, a sealing material 35 is injected, and after a predetermined amount of the sealing material 35 is injected, the sealing material 35 is solidified. Thereby, the insulation and waterproofness of the electrical junction box 10 can be ensured.

  In the electrical connection box 10 described above, the sealing material 35 is used for the portion where the bus bar 19 and the inner wall surfaces of the side walls 36A and 36B of the frame body 14 are in contact with each other. It may not be possible to enter between the inner wall surface and a slight gap may occur.

  In view of this point, in the present embodiment, the entire circumference of the bent portions 20A and 20B is surrounded by the sealing material 35 in the resin wrapping gaps 38A and 38B. As a result, when the fuse 24 is inserted into and removed from the fuse block 22, a force in the insertion / extraction direction of the fuse 24 (the left-right direction in FIG. 4) acts on the bending portion 20A, so that the bending portion 20A has a frame in FIG. Even when displaced so as to be peeled off from the inner wall surface of the right side wall 36A of the body 14, the entire circumference of the bent portion 20A is surrounded by the sealing material 35 in the resin wrapping gap 38A as described above. As a result, even if moisture passes through the bus bar 19 and enters the casing 12 from the end of the bus bar 19 protruding into the fuse block 22, the moisture enters the circuit board 11 side through the resin wrap-around gap 38A. Can be prevented. Thereby, the waterproofness of the electrical junction box 10 can be improved.

  Similarly, when the mating connector 26 is inserted into or removed from the connector block 25, the entire circumference of the bent portion 20B is surrounded by the sealing material 35 in the resin wrapping gap 38B. Even if moisture is transmitted through the bus bar 19 from the protruding end of the bus bar 19, it is possible to prevent the moisture from entering the circuit board 11 beyond the resin surrounding gap 38B.

  In addition, recesses 37A and 37B are formed in the inner wall surface of the side wall 36A and 36B of the frame body 14 along the bent portions 20A and 20B, and the resin wrapping gaps 38A and 37B are formed by the recesses 37A and 37B. The waterproof property of the electrical junction box 10 can be improved by a simple method of configuring 38B.

  Further, when the fuse 24 is inserted into and removed from the fuse block 22, the direction in which the fuse 24 is detached from the bus bar 19 by the frictional force acting between the end of the bus bar 19 and the fuse 24 (right direction in FIG. 4). Even if this force is applied, the bus bar 19 is firmly supported by the surface of the inner wall surface of the side wall 36A of the frame body 14 that is orthogonal to the insertion / extraction direction of the fuse 24. As a result, even if a force acts on the bus bar 19 when the fuse 24 is detached, the bus bar 19 can be prevented from being deformed.

  Similarly, when the mating connector 26 is detached from the connector block 25, the mating connector 26 is detached from the bus bar 19 by the frictional force acting between the end of the bus bar 19 and the fuse 24 (FIG. 5). Even if a force in the left direction is applied, the bus bar 19 is firmly supported by a surface of the inner wall surface of the side wall 36B of the frame body 14 that is orthogonal to the insertion / extraction direction of the mating connector 26. . As a result, even if a force acts on the bus bar 19 when the mating connector 26 is detached, the bus bar 19 can be prevented from being deformed.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention, and further, within the scope not departing from the gist of the invention other than the following. Various modifications can be made.

  (1) In the present embodiment, the resin surrounding air gaps 38A and 38B are formed by forming the recesses 37A and 37B in the portions along the bus bar 19 of the side walls 36A and 36B of the frame body 14, but the present invention is not limited to this. For example, a portion of the bus bar 19 along the side walls 36A and 36B of the frame body 14 is bent and formed so as to be partially separated from the side walls 36A and 36B, thereby forming resin wrapping spaces 38A and 38B. When the periphery is surrounded by the sealing material 35, the recesses 37A and 37B can be omitted.

  (2) In the present embodiment, the bus bar 19 is configured to be along the surface orthogonal to the insertion / extraction direction of the electrical component such as the fuse 24 on the inner wall surface of the frame body 14. Deformation of the bus bar 19 by receiving a force applied to the end of the bus bar 19 during insertion / extraction of the electrical component, such as providing an orthogonal portion extending perpendicular to the direction and providing a clamping member for clamping the orthogonal portion from the insertion / extraction direction of the electrical component If the configuration is such that the bus bar 19 can be placed along a surface that is not orthogonal to the insertion / extraction direction of the electrical component.

The perspective view of the electrical junction box concerning this embodiment The perspective view from the direction different from FIG. 1 of the electrical junction box which concerns on this embodiment Partially enlarged exploded perspective view of the electrical junction box AA line sectional view in FIG. BB sectional view in FIG. Top view of the frame CC sectional view in FIG. DD sectional view in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Electrical junction box 11 ... Circuit board 12 ... Casing 17 ... Insulating board 19 ... Bus bar 21 ... Bus bar outlet 24 ... Fuse (electrical equipment)
26 ... Mating connector (electrical component)
37A, 37B ... concave portion 35 ... sealing material 38A, 38B ... resin wrapping gap

Claims (3)

A circuit board formed by arranging a bus bar along an insulating substrate is accommodated in a container-like casing, and the bus bar is led out from a bus bar outlet formed in the casing along the inner wall surface of the casing. In the electrical junction box filled with a sealing material so as to bury the circuit board in the casing,
A portion of the bus bar extending from the circuit board and extending along the inner wall surface of the casing is partially formed with a resin wrapping gap with the inner wall surface of the casing. An electrical junction box characterized in that the material is filled around the entire circumference of the bus bar. The electrical junction box according to claim 1, wherein the resin wrapping gap is formed by forming a recess in an inner wall surface of the casing. An electrical component can be inserted / removably attached to a front end portion of the bus bar protruding from the casing, and the bus bar extends along a surface orthogonal to the insertion / extraction direction of the electrical component on the inner wall surface of the casing. The electrical junction box according to claim 1 or 2, wherein the electrical junction box is provided.

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