JP5370733B2 - Electrical junction box - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrical connection box which restrains the inside of a casing from becoming a partially high temperature and prevents a circuit structure from warping. <P>SOLUTION: The electrical connection box 10 includes the circuit component 11, which includes a circuit, and a cover 12, which is assembled to the circuit component 11. The circuit component 11 is equipped with a circuit board 13, which has a first sursurface and a second surface, a bus bar 15, which is superposed on the second surface of the circuit board 13, and a synthetic resin member 16, which is molded on the second surface of the circuit board 13, in a state where the circuit board 13 and the bus bar 15 are piled up. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an electrical junction box.

Conventionally, as an electrical junction box mounted on a vehicle, for example, the one described in Patent Document 1 is known. The electrical junction box is disposed between the battery and the on-vehicle electrical components such as a lamp and a wiper, and executes switching of the on-vehicle electrical components. This electrical junction box is formed by housing a circuit board in a case. Electronic components such as control elements are mounted on the circuit board.
JP-A-11-274766

  In the electrical junction box, heat generated in the electronic component and the circuit board during energization is transferred to the air layer between the circuit board and the case. Since air has a relatively low thermal conductivity, heat tends to be trapped. For this reason, there is a concern that the inside of the case becomes locally hot. Then, for example, there is a concern that the electrical connection reliability of the circuit board may be lowered due to, for example, a crack occurring at a connection portion between the electronic component and the circuit board.

  In order to solve the above problem, for example, a surface of the circuit board opposite to the surface on which the electronic component is mounted is covered with a synthetic resin member to form a circuit structure, and the synthetic resin member is attached to the case. It is considered that the synthetic resin member is exposed to the outside by being used as a part. Thereby, the heat generated in the electronic component and the circuit board when energized is transferred to the synthetic resin member and then dissipated from the synthetic resin member exposed to the outside. As a result, it is expected that the inside of the case is suppressed from becoming locally hot.

  However, according to the above configuration, the surface of the circuit board on which the electronic component is mounted is convex because the synthetic resin member molded on the side opposite to the surface on which the electronic component is mounted on the circuit board is molded and contracted. There is a concern that the circuit structure is warped in the shape.

  The present invention has been completed based on the above circumstances, and provides an electrical junction box in which the inside of the case is locally heated and the circuit structure is prevented from warping. Objective.

The present invention is an electrical junction box comprising a circuit structure including a circuit and a cover assembled to the circuit structure, the circuit structure having a first surface and a second surface; , the bus bar overlaid on the second surface of the circuit board, and a molded synthetic resin member on the second surface side of the circuit board in a laminated state and the circuit board and the bus bar, said cover Is attached to the synthetic resin member so as to cover the first surface of the circuit board, and the cover protrudes toward the circuit board and protrudes against the first surface of the circuit board. The convex portion is formed at a position corresponding to the peripheral edge portion of the circuit board in the cover, and the synthetic resin member and the convex portion are located at positions outside the thickness direction of the convex portion. A packing that is in close contact with the cover is arranged. It is .

  When the synthetic resin member molded on the second surface side of the circuit board is molded and contracted, the circuit structure tends to warp in a shape in which the first surface of the circuit board is convex. According to the present invention, by overlapping the bus bar on the circuit board, the bus bar can be reinforced to prevent the circuit structure from warping.

  Further, by superimposing the bus bar on the circuit board, the heat generated from the circuit can be equalized by the bus bar. As a result, the temperature rise in the case can be suppressed.

In addition, since the convex portion comes into contact with the first surface of the circuit board and the packing is in close contact with the synthetic resin member and the cover, the intrusion of water can be suppressed, and leakage and malfunction can be suppressed.

As embodiments of the present invention, the following embodiments are preferable.
The circuit board is formed with a first resin filling hole penetrating the circuit board, and the bus bar is formed with a second resin filling hole penetrating the bus bar at a position aligned with the first resin filling hole. A filling portion in which the synthetic resin member is filled by molding may be formed in the first resin filling hole and the second resin filling hole.

According to said aspect, a circuit board and a bus-bar can be fixed by the filling part filled in the 1st resin filling hole and the 2nd resin filling hole. Thereby, even when a force in a direction in which the circuit board and the bus bar are peeled off is applied by molding shrinkage of the synthetic resin member, the circuit board and the bus bar can be kept in a fixed state.
Moreover, the present invention is an electrical junction box, comprising a circuit structure including a circuit and a cover assembled to the circuit structure, and the circuit structure includes a first surface and a second surface. A board, a bus bar overlaid on the second surface of the circuit board, and a synthetic resin member molded on the second surface side of the circuit board in a state where the circuit board and the bus bar are overlaid, The circuit board is formed with a first resin filling hole penetrating the circuit board, and the bus bar is formed with a second resin filling hole penetrating the bus bar at a position aligned with the first resin filling hole. A filling portion in which the synthetic resin member is filled by molding is formed in the first resin filling hole and the second resin filling hole .
As embodiments of the present invention, the following embodiments are preferable.
The cover is assembled to the synthetic resin member so as to cover the first surface of the circuit board. The cover protrudes toward the circuit board and contacts the first surface of the circuit board. It is preferable that a convex portion is formed.

  The bus bar is a non-circuit and is preferably a heat radiating metal member.

  ADVANTAGE OF THE INVENTION According to this invention, it can suppress that the inside of a case becomes high temperature locally and a circuit structure body curves.

  An embodiment in which the present invention is applied to an on-vehicle electrical junction box 10 will be described with reference to FIGS. The electrical junction box 10 according to the present embodiment is disposed between a battery (not shown) and on-vehicle electrical components (not shown) such as a lamp and a wiper, and performs switching of the on-vehicle electrical components. The electrical junction box 10 is formed by assembling a cover 12 to a circuit structure 11 including a circuit. In the following description, the upper side in FIG. 2 is the upper side, the lower side is the lower side, the left side is the left side, and the right side is the right side. Also, the left side in FIG. 4 will be described as the front side and the right side will be described as the back side.

(Circuit structure 11)
As shown in FIG. 4, the circuit structure 11 includes a circuit board 13 and a bus bar 15 laminated on the back surface 14 of the circuit board 13 (the right side surface in FIG. 4, which corresponds to the second surface described in the claims). And a synthetic resin member 16 molded in a state where the circuit board 13 and the bus bar 15 are laminated.

(Circuit board 13)
As shown in FIG. 6, the circuit board 13 has a substantially rectangular shape elongated in the left-right direction (the direction from the left back side to the right front side in FIG. 6). As shown in FIG. 4, a conductive path (not shown) is formed on the surface 17 of the circuit board 13 (left side in FIG. 4, corresponding to the first surface described in the claims) by a printed wiring technique. Yes. The conductive path may be formed on the back surface 14 (the right side surface in FIG. 4) of the circuit board 13. An electronic component 18 is electrically connected to the conductive path of the circuit board 13 by a known method such as soldering. A circuit is formed on the circuit board 13 by conductive paths and electronic components 18.

(Bus bar 15)
The bus bar 15 is formed by pressing a metal plate material into a predetermined shape. The bus bar 15 is molded by the synthetic resin member 16 in a state of being laminated on the back surface 14 (the right side surface in FIG. 4) of the circuit board 13. The synthetic resin member 16 is disposed on the back surface 14 side (right side in FIG. 4) of the circuit board 13.

  The circuit board 13 and the bus bar 15 may be configured to be molded by the synthetic resin member 16 after the bus bar 15 is bonded to the back surface 14 of the circuit board 13 via an insulating adhesive layer. The adhesive layer may be an adhesive applied to the circuit board 13 or the bus bar 15 or may be an adhesive sheet (not shown), and relative movement between the circuit board 13, the adhesive sheet, and the bus bar 15 is restricted. In this state, the circuit board 13, the adhesive sheet, and the bus bar 15 may be integrated by molding with the synthetic resin member 16.

(Synthetic resin member 16)
As the synthetic resin member 16, a thermosetting resin or a thermoplastic resin can be used. As the thermosetting resin, any thermosetting resin such as an epoxy resin can be used as necessary. As the thermoplastic resin, any thermoplastic resin such as PPS, polyamide, or polyester can be used as necessary.

  As shown in FIG. 6, the synthetic resin member 16 has a frame portion 19 that surrounds the side edge of the circuit board 13 with the surface 17 (upper surface in FIG. 6) of the circuit board 13 exposed. The shape of the frame portion 19 generally follows the shape of the circuit board 13 and has a substantially rectangular shape elongated in the left-right direction (the direction from the left back side to the right front side in FIG. 6). As shown in FIG. 4, the synthetic resin member 16 has a bottom portion 20 formed on the back side of the circuit board 13 and the bus bar 15.

  As shown in FIG. 6, in the lower end of the circuit board 13 (the left front side in FIG. 6), the positions near the left and right ends (the left back side and the right front side in FIG. 6) pass through the circuit board 13. One resin filling hole 21 is formed. In the present embodiment, two first resin filling holes 21 are formed. One first resin filling hole 21 may be formed in the circuit board 13, or three or more may be formed. Moreover, the 1st resin filling hole 21 can be formed in the arbitrary positions of the circuit board 13 as needed.

  As shown in FIG. 4, a second resin filling hole 22 that penetrates the bus bar 15 is formed in the bus bar 15 at a position aligned with the first resin filling hole 21 of the circuit board 13. A filling portion 23 filled with the synthetic resin member 16 is formed in the first resin filling hole 21 and the second resin filling hole 22. The filling portion 23 is formed by the liquid synthetic resin member 16 flowing into the first resin filling hole 21 and the second resin filling hole 22 and then solidifying during molding.

(Connector 24)
As shown in FIG. 4, a connector 24 made of synthetic resin is disposed at a position near the upper end of the circuit structure 11 (closer to the upper end in FIG. 4). The connector 24 includes a hood portion 25 that opens downward (downward in FIG. 4) and can be fitted with a mating connector (not shown). As shown in FIG. 7, the connector 24 is formed to be elongated in the left-right direction (the direction from the left back side to the right front side in FIG. 7). The length dimension of the connector 24 in the left-right direction is substantially the same as the length dimension of the circuit board 13 in the left-right direction. In the connector 24, a plurality of hood portions 25 are formed side by side in the left-right direction (the direction from the left back side to the right front side in FIG. 7).

  As shown in FIG. 4, an attachment portion 26 that protrudes toward the circuit board 13 is formed on the back side (right side in FIG. 4) of the hood portion 25. The attachment portion 26 is formed with a screw attachment hole 27 that faces in the front and back direction (left and right direction in FIG. 4).

  The circuit board 13 is formed with a first screw insertion hole 28 that penetrates the circuit board 13 in alignment with the screw attachment hole 27 at a position corresponding to the attachment portion 26 of the connector 24. The bus bar 15 has a second screw insertion hole 29 penetrating the bus bar 15 at a position aligned with the first screw insertion hole 28 of the circuit board 13. Furthermore, a third screw insertion hole 30 that penetrates the synthetic resin member 16 is formed in the synthetic resin member 16 at a position aligned with the second screw insertion hole 29 of the bus bar 15. The connector 24 is inserted into the first screw insertion hole 28, the second screw insertion hole 29, and the third screw insertion hole 30 from the back side (right side in FIG. 4) of the circuit component 11, and is attached to the connector 24. It is attached to the circuit component 11 by being screwed into the 26 screw attachment holes 27.

  As shown in FIG. 4, the connector 24 is provided with a metal connector terminal 31. One end portion of the connector terminal 31 is disposed in the hood portion 25. The connector terminal 31 is formed integrally with the connector 24 by being molded. The connector terminal 31 may be arranged in the connector 24 by being press-fitted into the connector 24.

  As shown in FIG. 4, the other end of the connector terminal 31 protrudes from the connector 24 and is bent at a right angle toward the circuit component 11 side. As shown in FIG. 4, a part of the connector terminal 31 penetrates the circuit board 13 and is electrically connected to a connection portion 32 provided on the bus bar 15 by a known method such as welding, brazing, or soldering. It is connected. The connection part 32 of the bus bar 15 is formed by bending the end of the bus bar 15 in a direction intersecting the plate surface of the circuit board 13. In the present embodiment, the end portion of the bus bar 15 is bent substantially at a right angle toward the back side (right side in FIG. 4) of the circuit structure 11. In this manner, the connector terminal 31 and the bus bar 15 can be easily connected by bending the connection portion 32 in a direction intersecting the plate surface of the circuit board 13.

  As shown in FIG. 5, the other part of the connector terminal 31 protrudes from the connector 24 toward the circuit board 13, penetrates the circuit board 13, and is soldered to the conductive path of the circuit board 13. It is electrically connected by a known method.

  Further, as shown in FIG. 4, a convex rib 38 surrounding the connector terminal 31 and the screw 36 is provided on the back surface of the synthetic resin member 16 (the right side surface in FIG. 4) so as to protrude on the back side. The convex rib 38 surrounds the connector terminal 31 protruding from the back surface 14 of the terminal circuit board 13 and the screw 36 to form a closed loop shape. By filling the filler 39 in the region surrounded by the convex ribs 38, the connector terminals 31 and the screws 36 are protected from dust and water. The filler 39 can be filled with rubber or gel filler by potting or low pressure molding.

(Cover 12)
As shown in FIG. 4, the cover 12 made of synthetic resin is assembled to the circuit structure 11 and covers the surface 17 (the left surface in FIG. 4) of the circuit board 13. As shown in FIG. 7, the frame portion 19 of the synthetic resin member 16 is formed with a plurality of lock protrusions 33 that protrude outward from the outer edge of the frame portion 19. As shown in FIG. 1, a lock receiving portion 34 that is elastically engaged with the lock projection 33 is formed on the side wall of the cover 12 at a position corresponding to the lock projection 33 of the frame portion 19. . The lock projection 33 of the synthetic resin member 16 and the lock receiving portion 34 of the cover 12 are elastically engaged, so that the cover 12 is integrally assembled to the synthetic resin member 16 (circuit structure 11). It has become.

  When the cover 12 is brought closer from the front side of the circuit structure 11, the lock receiving portion 34 of the cover 12 comes into contact with the lock protrusion 33 of the frame portion 19 from the front side. When the cover 12 is further brought closer to the circuit structure 11, the lock receiving portion 34 is elastically bent and deformed, and rides on the lock protrusion 33. When the cover 12 is further brought closer to the circuit component 11, the lock receiving portion 34 is restored and deformed, and the lock receiving portion 34 and the lock projecting portion 33 are engaged, whereby the cover 12 and the synthetic resin member 16 are integrated. Assembled.

  As shown in FIG. 4, the cover 12 covers the connector 24 from the front side (left side in FIG. 4) and the upper side (upper side in FIG. 4).

  As shown in FIG. 4, the back surface (the right side surface in FIG. 4) of the synthetic resin member 16 is exposed to the external space in a state where the cover 12 is assembled to the circuit structure 11.

  As shown in FIG. 4, the inner surface of the cover 12 protrudes toward the circuit component 11 side and abuts against the surface 17 (the left side surface in FIG. 4) of the circuit board 13 to attach the circuit board 13 to the synthetic resin member 16. A convex portion 35 that abuts on the side is formed. The circuit board 13 is sandwiched between the convex portion 35 of the cover 12 and the synthetic resin member 16.

  The convex portion 35 is formed at a position corresponding to the peripheral portion of the circuit board 13 in the cover 12. Thereby, the convex portion 35 of the cover 12 comes into contact with the peripheral portion of the circuit board 13.

  Further, as shown in FIG. 4, the convex portion 35 is in contact with both the upper end portion (upper end in FIG. 4) and the lower end portion (lower end in FIG. 4) of the circuit board 13. As described above, the circuit board 13 has an elongated rectangular shape in the left-right direction (direction passing through the paper surface in FIG. 4), so that the convex portion 35 is at the end of the circuit board 13 that extends in the longitudinal direction. It is in contact with the circuit board 13.

  As shown in FIG. 4, a packing 37 is disposed at an outer position in the thickness direction of the convex portion 35. The packing 37 is in close contact with the surface of the synthetic resin member 16 (the left surface in FIG. 4) and the inner wall surface of the cover 12.

  Then, the effect | action and effect of this embodiment are demonstrated. According to the present embodiment, the circuit component 11 is formed by covering the back surface 14 of the circuit board 13 by overlapping the bus bar and molding with the synthetic resin member 16. The back surface of the synthetic resin member 16 is exposed to the external space. Thereby, the heat generated in the electronic component 18 and the circuit board 13 when energized is diffused by the bus bar 15 and transmitted to the synthetic resin member 16, and then dissipated from the synthetic resin member 16 exposed to the outside.

  Furthermore, by forming a bus bar circuit with the bus bar 15, circuit heat generation can be reduced and equalization can be achieved as compared with circuit arrangement using only the circuit board 13. As a result, the inside of the electrical junction box 10 is suppressed from becoming locally hot.

  Further, when the synthetic resin member 16 is molded on the back surface 14 of the circuit board 13, the circuit structure 11 is warped in a shape in which the front surface 17 of the circuit board 13 is convex due to molding shrinkage of the synthetic resin member 16. There is concern. From the above viewpoint, the bus bar 15 is overlaid on the circuit board 13 in the present embodiment. By being reinforced by the bus bar 15, it is possible to suppress the circuit structure 11 from warping.

  Furthermore, according to the present embodiment, the peripheral portion of the circuit board 13 is brought into contact with the synthetic resin member 16 side by the convex portion 35. Thereby, it can suppress that the circuit structure 11 warps by thermal expansion and contraction at the time of use (for example, at the time of switching).

  In addition, the convex portion 35 is in contact with an upper end portion and a lower end portion extending in the longitudinal direction of the circuit board 13. Thereby, it can suppress further that the circuit board 13 warps.

  In the present embodiment, the convex portion 35 contacts the surface 17 of the circuit board 13, and the packing 37 is in close contact with the surface of the synthetic resin member 16 and the inner wall surface of the cover 12. As a result, first, the packing 37 can prevent water from entering between the cover 12 and the synthetic resin member 16. Furthermore, the intrusion of water can be further suppressed by the protrusions 35 coming into contact with the surface 17 of the circuit board 13. As a result, leakage and malfunction can be suppressed.

  Moreover, according to this embodiment, the circuit board 13 and the bus bar 15 can be fixed by the filling portion 23 filled in the first through hole and the second through hole. Thereby, even when a force in a direction in which the circuit board 13 and the bus bar 15 are peeled off is applied due to molding shrinkage of the synthetic resin member 16, the state in which the circuit board 13 and the bus bar 15 are fixed can be maintained.

<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 bus bar 15 is a non-circuit and may be a heat radiating metal member.
(2) When the bus bar 15 is a heat radiating metal member, the heat radiating metal member may be locally exposed from the synthetic resin member 16.
(3) The first resin filling hole 21, the second resin filling hole 22, and the filling portion 23 may be omitted.
(4) The cover 12 and the synthetic resin member 16 may be assembled together by screwing. Further, the cover 12 and the synthetic resin member 16 may be vibration welded. Thus, the cover 12 and the synthetic resin member 16 can be integrally assembled by an arbitrary method as necessary.

The perspective view which shows the electric junction box which concerns on one Embodiment of this invention. Front view showing the electrical junction box Bottom view showing electrical junction box Sectional view along line IV-IV in FIG. VV line sectional view in FIG. The perspective view which shows the state which molded the synthetic resin member on the circuit board The perspective view which shows the state which attached the circuit board to the connector

DESCRIPTION OF SYMBOLS 10 ... Electrical junction box 11 ... Circuit structure 12 ... Cover 13 ... Circuit board 14 ... Back surface (2nd surface)
15 ... Bus bar 16 ... Synthetic resin member 17 ... Front surface (first surface)
21 ... 1st resin filling hole 22 ... 2nd resin filling hole 23 ... Filling part 35 ... Convex part

Claims (5)

A circuit structure including a circuit, and a cover assembled to the circuit structure,
The circuit structure includes a circuit board having a first surface and a second surface, a bus bar overlaid on the second surface of the circuit board, and the circuit board and the bus bar in a state where the circuit board and the bus bar are overlaid. A synthetic resin member molded on the two sides ,
The cover is assembled to the synthetic resin member so as to cover the first surface of the circuit board. The cover protrudes toward the circuit board and contacts the first surface of the circuit board. A convex part is formed,
The convex portion is formed at a position corresponding to the peripheral edge portion of the circuit board in the cover, and the synthetic resin member and the packing that is in close contact with the cover are disposed at a position outside the thickness direction of the convex portion. Is an electrical junction box. The circuit board is formed with a first resin filling hole penetrating the circuit board, and the bus bar is formed with a second resin filling hole penetrating the bus bar at a position aligned with the first resin filling hole. The electrical junction box according to claim 1, wherein a filling portion in which the synthetic resin member is filled by molding is formed in the first resin filling hole and the second resin filling hole . A circuit structure including a circuit, and a cover assembled to the circuit structure,
The circuit structure includes a circuit board having a first surface and a second surface, a bus bar overlaid on the second surface of the circuit board, and the circuit board and the bus bar in a state where the circuit board and the bus bar are overlaid. A synthetic resin member molded on the two sides,
The circuit board is formed with a first resin filling hole penetrating the circuit board, and the bus bar is formed with a second resin filling hole penetrating the bus bar at a position aligned with the first resin filling hole. An electrical junction box in which a filling portion in which the synthetic resin member is filled by molding is formed in the first resin filling hole and the second resin filling hole . The cover is assembled to the synthetic resin member so as to cover the first surface of the circuit board. The cover protrudes toward the circuit board and contacts the first surface of the circuit board. The electrical junction box according to claim 3, wherein a convex portion is formed . The electrical connection box according to claim 1, wherein the bus bar is a non-circuit and is a heat radiating metal member.

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