JP2005117741A - Electric connection box - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric connection box of which the number of components is minimum while assembling is easy. <P>SOLUTION: An electric connection box 1 comprises a board 102 on which an electric component 124 which heats is mounted and a case 6 for housing the board 102. The case 6 is made from heat conductive metal and has an integrated box shape having an internal space 26 with an upper wall 10 being continuous with a bottom wall 12. One side of the case is provided with an opening 16 which is communicated with the internal space 26 and guides the board 102 into the internal space 26. A leaf spring 42 of metal having heat conductivity is arranged in the internal space 26 of the case 6, with an electric connector 104 connected to one end of the board 102. When the board 102 is inserted in the internal space 26 through the opening 16, the board 102 contacts the leaf spring 42 and the opening 16 is closed with the electric connector 104. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a junction box, that is, an electrical junction box, and more particularly to an electrical junction box having a substrate on which a heat generating electrical (electronic) component is mounted, for example, mounted on a vehicle body and used for engine control of an automobile. .

As this type of electrical junction box, there is known an electrical junction box having a printed circuit board on which a heat-generating electrical (electronic) component such as a transistor is mounted, and separate upper and lower cases for accommodating the printed circuit board. (Patent Document 1). The upper case and the lower case are combined such that the engaging portion provided on the side edge of the upper case and the protrusion provided on the side edge of the lower case corresponding to the engaging portion are engaged with each other. It is configured. In this prior art electric junction box, in order to dissipate the heat-generated printed circuit board by the heated electrical components, an insulating sheet with high thermal conductivity is stuck on the upper surface of the lower case between the printed circuit board and the lower case. doing. The heat of the printed circuit board is radiated to the outside through the insulating sheet and the lower case.
Japanese Patent Laid-Open No. 5-15036 (FIG. 1)

 In the above prior art, in order to facilitate the assembly of the electrical junction box, an insulating sheet is stuck on the lower case opened upward from above. That is, since it is necessary to affix the insulating sheet on the upper surface of the lower case, the upper case and the lower case are separated. Thus, since the upper case and the lower case cannot be made into an integral type that cannot be separated, there is a problem that the number of parts increases.

 Also, if the upper case and the lower case are integrated, a flexible insulating sheet is inserted from the side and affixed to the lower case, but this operation is cumbersome and reduces assembly workability. . Moreover, it is difficult to confirm whether or not the insulating sheet is correctly attached.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electrical junction box that can minimize the number of parts and can be easily assembled.

  The electrical junction box of the present invention is an electrical junction box having a substrate on which a heat-generating electrical component is mounted and a case for housing the substrate. The case has an internal space, and the upper wall and the bottom wall are substantially continuous. A metal plate made of a box-shaped integral heat conductive metal, having an opening communicating with the internal space on one side of the case to introduce the substrate into the internal space, and having heat conductivity in the internal space of the case A spring is arranged, an electrical connector is connected to one end of the board, and when the board is inserted into the internal space from the opening, the board contacts the leaf spring, and the opening is closed by the electrical connector. is there.

  Here, the electric parts here are generic names of parts mounted on a substrate such as a power transistor, an electric connector, a fuse, and a relay.

   Moreover, it is preferable that a guide groove for guiding the substrate when the substrate is inserted is formed on the opposing inner side surfaces of the internal space of the case.

  Also, the leaf spring has a tongue piece with the spring tip folded back, and a leaf spring receiving portion having a forward facing surface is provided along the guide groove in the internal space, and the leaf spring is disposed in the leaf spring receiving portion. At the same time, the tongue piece can be press-fitted and fixed in a mounting groove formed on the front-facing surface, and the leaf spring can be fixed to the leaf spring receiving portion.

  The electrical connector may have a waterproof member that seals the opening when the electrical connector is attached to the opening at a position corresponding to the opening. The electrical connector may have a face plate that covers the opening of the case, and the waterproof member may be provided at a position corresponding to the opening around the face plate.

 The electrical junction box of the present invention is composed of a substantially box-shaped integral heat conductive metal having a case in which the case has an internal space and the upper wall and the bottom wall are continuous. There is an opening to be introduced into the internal space, a metal leaf spring having thermal conductivity is arranged in the internal space of the case, an electrical connector is connected to one end of the board, and the board is inserted into the internal space from the opening Since the substrate comes into contact with the leaf spring and the opening is closed by the electrical connector, the following effects can be obtained.

 That is, since the case is made of an integral metal, the number of parts is minimized. Further, since a heat dissipating leaf spring is disposed in advance in the internal space of the case, it can be easily assembled only by inserting the substrate into the internal space from one side surface of the case.

  In addition, when a guide groove for guiding the substrate when the substrate is inserted is formed on the opposing inner surface of the internal space of the case, the substrate can be stably inserted into the case and the substrate can be easily And can be reliably brought into contact with the leaf spring.

  Further, the leaf spring has a tongue piece with the tip of the leaf spring folded back, and a leaf spring receiving portion having a forward facing surface is provided along the guide groove in the internal space, and the leaf spring is provided in the leaf spring receiving portion. When the tongue piece is press-fitted and fixed in a mounting groove formed on the front-facing surface and the leaf spring is fixed to the leaf spring receiving portion, the plate is used without using an adhesive or the like. Since the spring can be easily attached to the case simply by inserting the spring from one side surface, the assembly workability is improved.

 In addition, if the electrical connector has a waterproof member that seals the opening when the electrical connector is attached to the opening at a position corresponding to the opening, the inside of the case can be sealed very easily without using an adhesive. It can be a structure.

  Hereinafter, a preferred embodiment of an electrical junction box of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is an exploded perspective view of the electrical junction box 1 of the present invention as viewed from the front, and FIG. 2 is an exploded perspective view of the electrical junction box 1 of FIG. 1 as viewed from the rear. Hereinafter, a description will be given with reference to FIGS. 1 and 2. The electrical junction box 1 includes a case assembly 2 and a substrate assembly 100. The case assembly 2 includes a case 6 integrally formed of a metal having good thermal conductivity (thermal conductive metal) such as aluminum die casting, and a leaf spring 42 fixed to the internal space 26 of the case 6 (FIG. 1). ). The case 6 has a substantially rectangular parallelepiped shape, and the upper wall 10, the bottom wall 12, the side walls 14, 14 and the rear wall 4 (FIG. 2) are integrally formed. The upper wall 10 and the bottom wall 12 are continuous via the side walls 14 and 14. A rectangular opening 16 (FIG. 1) that communicates with the internal space 26 is formed in the front portion that is one side surface of the case 6.

  The front upper wall 20 of the case 6 is raised from the upper wall 10 of the case 6 through the inclined portion 18, and is substantially rectangular surrounding the opening 16 from the front upper wall 20 to the side walls 14, 14 and the bottom wall 12. The flange 22 is formed. A peripheral wall 24 that defines the opening 16 is formed on the front surface of the flange 22. The peripheral wall 24 serves as a fitting portion when assembled with a substrate assembly 100 described later. In addition, mounting ribs 28 and 30 extending horizontally outward are formed on the bottom wall 12 side in front of the side walls 14 and 14. Each of the mounting ribs 28 and 30 is formed with a hole 28a and a notch 30a (FIG. 4), and is configured to be attached to a mounted portion such as a vehicle body by screwing. In addition, screw holes 56 for screwing in combination with the substrate assembly 100 are formed at the four corners of the flange 22.

  Next, the internal structure of the case assembly 2 will be described with reference to FIGS. 3 is a longitudinal sectional view of the case assembly 2 taken along line III-III in FIG. 5, FIG. 4 is a partial sectional view of the case assembly 2 taken along line IV-IV in FIG. 5, and FIG. Front views are shown respectively. FIG. 6 is a partial vertical cross-sectional view showing the front portion of the spring receiving portion 38 in a partially broken view, and FIG. 7 is a partial cross-sectional view showing a portion of the spring receiving portion 38 in cross section. As shown in FIG. 3, step portions 32 and 34 are formed on the inner surface (inner surface) 14 a of each side wall 14 from the opening 16 toward the inner side so that the interval between the inner surfaces 14 a is narrowed. A guide groove 36 for guiding a printed circuit board (hereinafter simply referred to as a board) 102 described later is formed from the front end surface 34a of the step part 34 to the inside.

  The guide groove 36 includes a passage portion 36a formed in parallel with the bottom wall 12 on the inner wall 14a near the bottom wall 12, and a guide portion 36b formed in the front portion of the passage portion 36a. The passage portion 36 a extends linearly with a width slightly larger than the thickness of the substrate 102. The guiding portion 36b is widened forward, and is configured to guide the substrate 102 when the substrate 102 is inserted. The leading portion 36b is formed with a tapered surface 58 facing forward, so that the substrate 102 does not contact the front end surface 34a when the substrate 102 is inserted.

  Next, the spring receiving portion 38 formed on the inner surface 12a of the bottom wall 12 in the vicinity of the guide groove 36 will be described with reference to FIGS. The spring receiving portion 38 is formed integrally with the bottom wall 12 and the side wall 14, protrudes in a rectangular shape from the inner surface 12 a of the bottom wall 12, and has a forward facing surface 40 facing forward. A mounting groove 54 is formed in the forward facing surface 40 so as to extend inward in parallel with the inner surface 12a. The upper surface 52 of the spring receiving portion 38 is formed flush with the lower surface of the passage portion 36 a of the guide groove 36. A shallow recess 50 that receives the leaf spring 42 is formed on the upper surface 52 over substantially the entire length of the upper surface 52. The depth of the recess 50 is set to a depth that allows the thickness of the leaf spring 42 to be received and allows a spring piece 48 to be described later to protrude from the recess 50.

  Next, the leaf spring 42 disposed in the spring receiving portion 38 will be described. The leaf spring 42 is formed from a single metal plate such as a copper alloy having springiness and good thermal conductivity, and is a flat base 46 (FIG. 4) disposed in the recess 50 described above. ) And a tongue piece 44 bent in a substantially U shape downward from the front end portion of the base portion 46. In the base 46, three spring pieces 48 are formed in the rectangular opening 47 by cutting up and bending along the longitudinal direction.

  Each spring piece 48 has a cantilever shape having a fixed end side at the front side, that is, the opening 16 side, and a free end side at the rear side. The spring piece 48 is formed with a contact portion 48a curved in a convex shape on the upper side, that is, on the guide groove 36 side. As shown in FIG. 3, the contact portion 48 a is positioned at substantially the same height as the guide groove 36 in the vertical direction, and is a portion that contacts the lower surface 102 a (FIGS. 6 and 7) of the substrate 102. In the leaf spring 42, the base portion 46 is disposed on the spring receiving portion 38, and the tongue piece 44 is press-fitted into the mounting groove 54 of the spring receiving portion 38 and fixed. In this manner, the leaf spring 42 can be fixed to the spring receiving portion 38 simply by pressing from the opening 16 side.

  Next, the substrate assembly 100 assembled with the case assembly 2 will be described with reference to FIGS. 1 and 2 again. The board assembly 100 includes a rectangular board 102 on which an electrical component 124 is mounted, and an electrical connector 104 connected to one end of the board 102. Note that one electrical component 124 is shown as an example, and a plurality of types of electrical components are generally arranged. The electrical connector 104 includes a rectangular face plate 106 having a size corresponding to the opening 16 of the case 6, and a fitting portion 108 projecting forward from the face plate 106. A plurality of terminals 110 are disposed in the fitting portion 108, and the tine portion 126 of the terminal 110 is inserted through the tine plate 136 and aligned. After being aligned, the tine portion 126 is inserted into a through hole (not shown) of the substrate 102 and fixed to the substrate 102 by soldering. A concave groove 120 that receives the peripheral wall 24 of the case 6 at the time of assembly is formed at a position corresponding to the opening 16 around the back side of the face plate 106.

  Next, the mounting relationship between the board 102 and the electrical connector 104 will be described with reference to FIG. FIG. 8 is a longitudinal sectional view of the electrical junction box 1 of the present invention in which the board assembly 100 and the case assembly 2 are combined. On both sides of the back surface of the face plate 106, substantially rectangular ribs 112 project integrally with the face plate 106. On the bottom surface 114 of the rib 112, a boss 116 and a latch projection 118 are provided so as to be spaced apart from each other. On the rear surface of the rib 112, two slits 130 (FIG. 2) that are spaced apart from each other and extend in the vertical direction and inward of the rib 112 are formed. The rib 112 further extends upward from the bottom surface 114 perpendicular to the slit 130 and is formed with another slit (not shown) that communicates with the two slits 130. An elastic arm 132 (FIG. 2) extending in the direction is formed integrally with the rib 112. The aforementioned latch protrusion 118 protrudes from the lower end of the elastic arm 132.

  These bosses 116 and latch protrusions 118 are inserted into corresponding through holes (not shown) of the board 102 to position and fix the board 102 and the electrical connector 104, respectively. Thus, the electrical connector 104 is attached so that the face plate 106 is substantially perpendicular to the substrate 102.

  Further, reference numeral 134 in FIG. 8 denotes a latch arm that projects integrally with the tine plate 136 (FIG. 2). The latch arm 134 has a claw 138 that is engaged with the upper surface of the rib 112 and positions the tine plate 136 in the vertical direction at the upper end. The latch arm 134 has a post 142 that is inserted into a predetermined positioning hole 140 of the substrate 102 and positions the tine plate 136 with respect to the substrate 102 at the lower end of the latch arm 134.

  When the board assembly 100 configured as described above is inserted into the case assembly 2 from the other end side of the board 102, the board 102 enters the internal space 26 along the guide groove 36, and the face plate of the electrical connector 104. 106 is attached to the opening 16. At that time, as described above, the peripheral wall 24 of the case 6 is received in the concave groove 120 of the face plate 106. Since the waterproof rubber member (waterproof member), that is, the packing 122 is disposed along the concave groove 120 in the concave groove 120, the packing 122 presses against the peripheral wall 24 to maintain the internal space 26 in a sealed state. Then, the board assembly 100 and the case assembly 2 are coupled to each other by the screws 128. In addition, the top view of the electrical junction box 1 at this time is shown in FIG. Thus, the board assembly 100 is configured integrally with the case assembly 2 in a state where the face plate 106 is in contact with the flange 22 of the case assembly 2.

  As can be seen from FIGS. 6 and 8, the spring piece 48 contacts the lower surface 102 a of the substrate 102. Then, the heat of the substrate 102 is conducted to the case 6 through the spring piece 48 and is radiated from the case 6 to the outside.

The exploded perspective view which looked at the electrical junction box of the present invention from the front The exploded perspective view which looked at the electrical junction box of FIG. 1 from back The longitudinal cross-sectional view of the case assembly which follows the III-III line | wire of FIG. 5 used for the electrical junction box of this invention Partial sectional view of the case assembly along line IV-IV in FIG. Front view of the case assembly of FIG. The partial longitudinal cross-sectional view which partially fractures | ruptures and shows the front part of the spring receiving part in the case assembly of FIG. FIG. 3 is a partial cross-sectional view showing a section of a spring receiving portion in the case assembly of FIG. Longitudinal sectional view of the electrical junction box of the present invention Plan view of the electrical junction box of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electrical junction box 6 Case 10 Upper wall 12 Bottom wall 14a Inner side surface 16 Opening 26 Internal space 36 Guide groove 38 Leaf spring receiving part 40 Front surface 42 Leaf spring 44 Tongue piece 54 Mounting groove 102 Substrate 104 Electric connector 122 Waterproof member 124 Electricity parts

Claims (4)

In an electrical junction box having a board on which a heat-generating electrical component is mounted, and a case for housing the board,
The case is made of a substantially box-shaped integral heat conductive metal having an internal space, the upper wall and the bottom wall of which are continuous, and the substrate is connected to the internal space on one side surface of the case. Has an opening to introduce into,
A metal leaf spring having thermal conductivity is disposed in the internal space of the case,
An electrical connector is connected to one end of the substrate, and when the substrate is inserted into the internal space from the opening, the substrate contacts the leaf spring, and the opening is closed by the electrical connector. Electrical junction box.   2. The electrical junction box according to claim 1, wherein a guide groove for guiding the substrate when the substrate is inserted is formed on opposing inner side surfaces of the internal space of the case. The leaf spring has a tongue that is folded at the tip of the leaf spring;
In the internal space, a leaf spring receiving portion having a forward facing surface is provided along the guide groove,
The leaf spring is disposed in the leaf spring receiving portion, and the tongue piece is press-fitted and fixed in a mounting groove formed on the forward facing surface, so that the leaf spring is fixed to the leaf spring receiving portion. The electrical junction box according to claim 1 or 2, characterized in that:   The said electrical connector has a waterproof member which seals this opening in the position corresponding to the said opening, when the said electrical connector is attached to the said opening. Electrical junction box.

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