Electrical connection box

Abstract

An electrical connection box (10) comprises: a circuit substrate (11) having a conductive path and having electronic components (15-17) installed thereon; a conductive first shielding shell (20) covering one side of the circuit substrate (11); a conductive second shielding shell (25) covering the side of the circuit substrate (11) opposite to the one side; a first resin shell (40) made of resin covering the first shielding shell (20); and a second resin shell (45) made of resin covering the second shielding shell (25).

Description

Technical Field

[0001] In this specification, a technology related to an electrical connection box is disclosed. Background Art

[0002] Conventionally, there is known an electrical connection box that accommodates a circuit substrate in a housing. The electrical connection box of Patent Document 1 comprises: a circuit substrate on which electronic components such as relays are mounted; a metal heat dissipation member stacked below the circuit substrate; and a metal housing that covers the upper side of the heat dissipation member stacked with the circuit substrate. The housing and the heat dissipation member of the electrical connection box cover the circuit substrate, so that the electrical connection box has a shielding function.

[0003] Prior Art Literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2014-103747 Summary of the invention

[0006] Problems to be solved by the invention

[0007] However, when the outer packaging of the electrical connection box is set as a metal shell in order to make the electrical connection box have a shielding function, the weight of the metal becomes an obstacle to lightweighting of the electrical connection box, and the durability of the mold during manufacturing is lower than that of a shell made of synthetic resin, so there is a problem that the manufacturing cost is easily increased.

[0008] The technology described in this specification has been accomplished based on the above-mentioned circumstances, and its purpose is to reduce the weight of the electrical junction box and the manufacturing cost.

[0009] Solutions to Solve Problems

[0010] The electrical connection box described in this specification comprises: a circuit substrate having a conductive path and mounted with electronic components; a conductive first shielding shell covering one side of the circuit substrate; a conductive second shielding shell covering the side of the circuit substrate opposite to the one side; a first resin shell made of resin covering the first shielding shell; and a second resin shell made of resin covering the second shielding shell.

[0011] According to the above structure, both sides of the circuit substrate are covered by the first shielding shell and the second shielding shell, and the outer sides of the first shielding shell and the second shielding shell are covered by the resin shell, so that the shielding function can be exerted on both sides of the circuit substrate, and the electrical connection box can be made lighter than the structure in which the outer package of the electrical connection box is a metal shell. Moreover, compared with the structure in which the outer package of the electrical connection box uses the shielding shell, the shielding shell can use a thin-walled metal plate, so the shielding shell becomes easy to shape and the manufacturing cost can be reduced.

[0012] The following aspects are preferred as embodiments of the technology described in this specification.

[0013] The electronic components are multiple, including high-noise components and low-noise components with less noise than the high-noise components, and at least one of the first shielding shell and the second shielding shell covers the surface of the circuit substrate in a manner that includes an area where the high-noise components are mounted in an area smaller than the entire area of ​​the circuit substrate.

[0014] One of the first shielding shell and the second shielding shell has a plate-shaped locked portion, and the other of the first shielding shell and the second shielding shell has a first locking piece and a second locking piece that clamp the locked portion, and the first locking piece and the second locking piece are arranged in parallel along the locked portion.

[0015] The conductive path includes a ground pattern connected to a ground potential, and at least one of the first shielding case and the second shielding case includes a fastening portion that is screwed to the circuit board and connected to the ground pattern.

[0016] At least one of the first shielding casing and the second shielding casing includes the fastening portion and a facing portion that faces the circuit board with a gap therebetween, and a step portion is formed between the fastening portion and the facing portion.

[0017] At least one of the first shielding case and the second shielding case includes a side wall portion having a plate surface in a direction intersecting with a plate surface of the circuit substrate, and an end of the side wall portion on the circuit substrate side forms a gap with a surface of the circuit substrate.

[0018] A capacitor is accommodated between the second shielding case and the second resin case.

[0019] Effects of the Invention

[0020] According to the technology described in this specification, the weight of the electrical junction box can be reduced and the manufacturing cost can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a perspective view showing an electrical junction box according to the embodiment.

[0022] Figure 2 is a top cross-sectional view of the electrical connection box.

[0023] Figure 3 Yes Figure 2 A magnified portion of the image.

[0024] Figure 4 yes Figure 2 AA section view.

[0025] Figure 5 Yes Figure 4 A magnified portion of the image.

[0026] Figure 6 yes Figure 2 BB cross-sectional view.

[0027] Figure 7 This is an exploded perspective view of the electrical connection box excluding the capacitor unit.

[0028] Figure 8 It is a perspective view showing the first shielding case and the second shielding case.

[0029] Fig. 9 It is a perspective view showing the interior of the electrical junction box in a state where the first shielding case and the second shielding case are assembled. DETAILED DESCRIPTION

[0030] Regarding implementation mode 1, refer to Figures 1 to 9 Provide explanation.

[0031] The electrical connection box 10 ( Figure 1 ) For example, in an electric vehicle or hybrid vehicle, it is provided separately from the main power supply that supplies the vehicle with driving force, and can be used as an auxiliary power supply that can supply power to the motor of the vehicle's electrical installation or equipment. Figure 1 The description will be given with the X direction being the left, the Y direction being the front, and the Z direction being the top.

[0032] like Figure 4 As shown, the electrical connection box 10 comprises: a circuit substrate 11; a first shielding shell 20 arranged on the upper surface side (one side) of the circuit substrate 11; a second shielding shell 25 arranged on the lower surface side (the opposite side of one side) of the circuit substrate 11; a capacitor unit 35 arranged on the lower side of the second shielding shell 25; and resin shells 40, 45 made of synthetic resin that accommodate the circuit substrate 11, the first shielding shell 20, the second shielding shell 25 and the capacitor unit 35.

[0033] The circuit substrate 11 uses a printed circuit board having a conductive path formed on an insulating board by a printed wiring technology, such as Figure 7As shown, a plurality of terminal insertion holes 12 for inserting the lead terminal 36A, a plurality of threaded holes 13 for inserting the shaft of the screw 52, ​​and a plurality of positioning holes 14A, 14B for positioning the circuit substrate 11 are formed through the circuit substrate 11. The plurality of threaded holes 13 and the plurality of positioning holes 14A, 14B are arranged at intervals on the peripheral portion of the circuit substrate 11. The positioning hole 14A is for inserting the positioning pin 37A (positioning portion) of the capacitor unit 35 to position the capacitor unit 35 relative to the circuit substrate 11. The positioning hole 14B is for inserting the positioning pin 48 (positioning portion) of the second resin case 45 to position the second resin case 45 relative to the circuit substrate 11. As shown in FIG. Figure 2 , Figure 4 As shown in FIG. 1 , a plurality of electronic components 15 to 17 are mounted on the conductive paths on both sides of the circuit substrate 11. The plurality of electronic components 15 to 17 are composed of FETs (Field effect transistors), resistors, diodes, coils, capacitors, microcomputers, etc., and their terminals are connected to the conductive paths of the circuit substrate 11. Figure 2 As shown, electronic components 15 such as FETs that are prone to generate noise based on switching are installed in the shielding area A1 covered by the first shielding shell 20 and the second shielding shell 25 in the circuit substrate 11, and electronic components 17 that are difficult to generate noise are installed in the non-shielding areas A2 and A3 outside the shielding area A1. The shielding area A1 on the lower surface side of the circuit substrate 11 is installed with electronic components 16 that are shorter (smaller in height in the vertical direction) than the shielding area A1 on the upper surface side of the circuit substrate 11. As the electronic components 16 with a short height, there are, for example, resistors, diodes, and capacitors with a short height. It should be noted that the circuit substrate 11 is not limited to a printed substrate. For example, a busbar made of metal plates such as copper and copper alloys can be overlapped on a printed substrate to form a circuit substrate.

[0034] Connector 18 is fixed to the front end of circuit board 11. Connector 18 includes housing 18A opened in a hood shape and connector terminals 18B fixed to housing 18A. Connector terminals 18B are connected to the conductive paths of circuit board 11 by soldering to lands of circuit board 11.

[0035] The first shielding shell 20 is made of metal such as iron, stainless steel, or aluminum, and is sized to cover the shielding area A1 on the upper surface of the circuit substrate 11. Figure 8 As shown in FIG. 1 , the top plate 21 has a rectangular shape, side walls 22, 22 extending downward from both side ends of the top plate 21, and end walls 23, 23 extending downward from the front and rear ends of the top plate 21. The end walls 23, 23 extend downward longer than the side walls 22, 22. Figure 6As shown in FIG. 1 , a gap CL1 is formed between the side wall portions 22, 22 and the upper surface of the circuit substrate 11. The lower end side (front end side) of the end wall portions 23, 23 is set as a locked portion 24. Figure 8 As shown, circular locked holes 24A formed through the locked portion 24 are arranged in the left and right.

[0036] The second shielding shell 25 is made of metal such as iron, stainless steel, and aluminum, and comprises: a rectangular relative portion 26 arranged relative to the lower surface of the circuit substrate 11 at a distance; a pair of side wall portions 27, 27 extending upward from the two side edges of the relative portion 26; overlapping portions 28, 28 extending in the front-to-back direction with respect to the relative portion 26 via a stepped step portion 32 and overlapping with the circuit substrate 11 in a close contact state; and a plurality of locking pieces 29A, 29B provided at the front end portions of the overlapping portions 28, 28 and standing upward (in a direction intersecting with the plate surface of the overlapping portions 28, 28). A plurality of through holes 26A for terminals to be inserted are formed in parallel on the overlapping portion 28 side of one of the relative portions 26. The side wall portions 27, 27 are smaller in height than the step portion 32, such as Figure 6 As shown, in a state where the second shielding case 25 is attached to the circuit board 11 , a gap CL2 is formed between the upper ends (front ends) of the side walls 27 , 27 and the lower surface of the circuit board 11 .

[0037] The overlapping parts 28, 28 overlap the front end and the rear end of the middle part of the circuit board 11 in the left-right direction, and have a fastening part 28B that is screwed and fastened by a screw 52. The fastening part 28B is formed with a plurality of threaded holes 28A through which the shafts of the screws 52 are inserted. Figure 8 As shown, a relief recess 28C is cut out in one of the overlapping portions 28, and the relief recess 28C is used to relieve the head of the screw 52 when the capacitor unit 35 is screwed. Figure 6 As shown, the shaft of the screw 52 is passed through the threaded holes 13 and 28A of the circuit substrate 11 and the overlapping portions 28 and 28 with the washer 53 inserted therethrough, and is tightened by the nut 54, whereby the circuit substrate 11 and the fastening portion 28B formed with the ground pattern GP are clamped between the head of the screw 52 and the nut 54. Thus, the second shielding case 25 is connected to the ground potential via the ground pattern GP.

[0038] Multiple locking pieces 29A, 29B such as Figure 8As shown, the locking pieces 29A and the locking pieces 29B are alternately arranged in the left-right direction, and a gap is formed between the position of the locking piece 29A and the position of the locking piece 29B in the front-back direction, and there are a plurality of rows of first locking pieces 29A and a plurality of rows of second locking pieces 29B. The locked portion 24 of the first shielding shell 20 can be clamped between the rows of the plurality of first locking pieces 29A and the rows of the plurality of second locking pieces 29B. Both the first locking piece 29A and the second locking piece 29B have a protrusion 30 protruding toward the side of the locked portion 24 (the inner side of each other). A depression corresponding to the shape of the protrusion 30 is formed on the surface of the locking pieces 29A, 29B on the side opposite to the protrusion 30. When the end wall portions 23, 23 of the first shielding shell 20 are inserted through the gap between the first locking piece 29A and the second locking piece 29B, the protrusion 30 abuts against the end wall portions 23, 23, causing the first locking piece 29A and the second locking piece 29B to be slightly elastically deformed, and the locked portion 24 is inserted between the first locking piece 29A and the second locking piece 29B. Moreover, by the engagement of each protrusion 30 with the plurality of locked holes 24A of the locked portion 24, the first locking piece 29A and the second locking piece 29B are elastically restored, and the first shielding shell 20 and the second shielding shell 25 are maintained in the assembled state. In this state, the locked portion 24 is in contact with the first locking piece 29A and the second locking piece 29B, so that the first shielding shell 20 is electrically connected to the ground potential via the second shielding shell 25, and the engagement of each protrusion 30 with the locked holes 24A restricts the first shielding shell 20 and the second shielding shell 25 from being separated. The first shielding case 20 and the second shielding case 25 can be formed by punching a thin metal plate into an expanded shape with a press machine and then bending the thin metal plate. The protrusion 30 can be formed by punching the metal plate with a press machine, for example.

[0039] like Figure 4 As shown, the capacitor unit 35 includes a plurality of capacitors 36 such as electric double layer capacitors and lithium ion capacitors, and a capacitor holder 37 made of synthetic resin for holding the plurality of capacitors 36 in parallel. The capacitor 36 is, for example, cylindrical and has a pair of positive and negative lead terminals 36A. The capacitor holder 37 includes a plurality of recessed portions (not shown) for fitting the plurality of capacitors 36 in a parallel state, and is covered by a capacitor cover 38 for restricting the plurality of capacitors 36 from being separated. The capacitor holder 37 is provided with a positioning pin 37A, which enters the avoidance recess 28C of the second shielding shell 25, is inserted into the positioning hole 14A, and positions the relative position of the circuit board 11 and the capacitor unit 35.

[0040] like Figure 7As shown, the resin housings 40, 45 include a first resin housing 40 and a second resin housing 45 that fits into the first resin housing 40. The first resin housing 40 is a box-shaped housing with an open lower side, and includes a square cylindrical peripheral wall portion 41 extending downward from the periphery of a rectangular plate-shaped top wall 40A. A plurality of frame-shaped locking frames 42 that can be flexibly deformed are arranged at intervals at the lower end of the peripheral wall portion 41 throughout the entire circumference. A lead-out recess 43 is cut out in the peripheral wall portion 41 of the first resin housing 40, and the lead-out recess 43 leads out the connector 18.

[0041] The second resin case 45 includes a rectangular plate-shaped bottom wall 45A and a square cylindrical rising wall 46 that rises upward from the periphery of the bottom wall 45A all around. A plurality of bosses 47A, 47B and a positioning pin 48 are provided on the inner side of the rising wall 46. The plurality of bosses 47A, 47B and the positioning pin 48 are arranged at intervals in the circumferential direction and are formed at positions adjacent to the rising wall 46. A recess 47C for accommodating the nut 54 in a state where the rotation of the nut 54 is restricted and a relief recess 47D for accommodating the shaft of the screw 52 are formed on the upper part of the plurality of bosses 47A, 47B. The positioning pin 48 is in the shape of a rod and is inserted into the positioning holes 14A, 14B of the circuit substrate 11 to position the circuit substrate 11. A locking projection 49 is formed on the outer periphery of the rising wall 46 of the second resin case 45 , and the locking projection 49 locks the locking frame 42 to restrict the first resin case 40 from being detached.

[0042] The assembly of the electrical connection box 10 will be described.

[0043] In a state where the capacitor unit 35 is housed in the second resin case 45 and the nuts 54 are housed in the recesses 47C of the second resin case 45, the overlapping portions 28, 28 of the second shielding case 25 are placed on the plurality of bosses 47A. Next, the circuit board 11 to which the connector 18 is mounted and the plurality of electronic components 15 to 17 are overlapped on the second shielding case 25 (see FIG. 1 ) in such a manner that the positioning pins 37A, 48 are inserted through the positioning holes 14A, 14B. Figure 7 ). Then, the shaft of the screw 52 is passed through the threaded hole 13 and the threaded hole 28A, and the circuit substrate 11 and the overlapping parts 28, 28 are fastened to the plurality of bosses 47A by the screw 52. The bosses 47B and the like are also fastened by the screw 52, ​​and the circuit substrate 11 is fixed to the second resin case 45.

[0044] Next, when the first shielding shell 20 is fitted into the second shielding shell 25 from the upper side of the circuit substrate 11, the locked portion 24 of the first shielding shell 20 is sandwiched between the first locking piece 29A and the second locking piece 29B in the second shielding shell 25, and the protrusions 30 of the first locking piece 29A and the second locking piece 29B are fitted into the locked hole 24A. As a result, the locked portion 24 is locked between the first locking piece 29A and the second locking piece 29B, and the shielding shells 20 and 25 are connected to the ground potential. In addition, the first resin shell 40 is covered on the second resin shell 45, and the hole edge of the locking frame 42 of the first resin shell 40 is locked to the locking protrusion 49 of the second resin shell 45, thereby forming the electrical connection box 10 ( Figure 1 ).

[0045] According to this embodiment, the following actions and effects are achieved.

[0046] The electrical connection box 10 comprises: a circuit substrate 11 having a conductive path and mounted with electronic components 15 to 17; a conductive first shielding shell 20 covering one side of the circuit substrate 11; a conductive second shielding shell 25 covering the side of the circuit substrate 11 opposite to the one side; a first resin shell 40 made of resin covering the first shielding shell 20; and a second resin shell 45 made of resin covering the second shielding shell 25.

[0047] According to the present embodiment, both sides of the circuit board 11 are covered by the first shielding shell 20 and the second shielding shell 25, and the outer sides of the first shielding shell 20 and the second shielding shell 25 are covered by the resin shells 40 and 45, so that the shielding area A1 on both sides of the circuit board 11 can have a shielding function, and the electrical connection box 10 can be made lighter than a structure in which the outer package of the electrical connection box 10 is a metal shell. Moreover, compared with a structure in which the outer package of the electrical connection box 10 uses a metal shell, the shielding shells 20 and 25 can use a thin-walled metal plate material, so that the shielding shells 20 and 25 can be easily formed, and the manufacturing cost can be reduced.

[0048] In addition, there are multiple electronic components 15 to 17, which include FETs (high-noise components) and coils (low-noise components) having less noise than FETs. At least one of the first shielding shell 20 and the second shielding shell 25 covers the surface of the circuit substrate 11 in a manner that includes a shielding area A1 on which FETs are installed in an area smaller than the entire area of ​​the circuit substrate 11.

[0049] In this way, compared with a structure in which the entire region of the circuit board 11 is covered with a shield case, it is possible to further reduce the weight of the electrical junction box 10 and the manufacturing cost.

[0050] In addition, the first shielding shell 20 (one of the first shielding shell 20 and the second shielding shell 25) has a plate-shaped fixed portion 24, and the second shielding shell 25 (the other of the second shielding shell 25 and the first shielding shell 20) has a first fixing piece 29A and a second fixing piece 29B that clamp the fixed portion 24, and the first fixing piece 29A and the second fixing piece 29B are arranged side by side along the fixed portion 24.

[0051] In this way, the assembly work of the first shielding housing 20 and the second shielding housing 25 can be simplified, and the fitted state of the first shielding housing 20 and the second shielding housing 25 can be maintained.

[0052] The conductive path includes a ground pattern GP connected to a ground potential, and the second shielding casing 25 (at least one of the second shielding casing 25 and the first shielding casing 20 ) includes a fastening portion 28B that is screwed to the circuit board 11 and connected to the ground pattern GP.

[0053] In this way, the shielding casings 20 and 25 can be connected to the ground potential by the structure for fixing the second shielding casing 25 (at least one of the second shielding casing 25 and the first shielding casing 20 ) to the circuit board 11 .

[0054] The second shielding casing 25 (at least one of the second shielding casing 25 and the first shielding casing 20 ) includes a fastening portion 28B and a facing portion 26 facing the circuit board 11 at a distance therefrom, and a step portion 32 is formed between the fastening portion 28B and the facing portion 26 .

[0055] In this way, a space for accommodating the electronic component 16 can be formed between the circuit board 11 and the facing portion 26 by the step portion 32 .

[0056] In addition, the first shielding shell 20 and the second shielding shell 25 (at least one of them) have a side wall portion 22 (27), which has a plate surface in a direction intersecting with the plate surface of the circuit substrate 11, and the end of the side wall portion 22 (27) on the circuit substrate 11 side forms gaps CL1 and CL2 between the surface of the circuit substrate 11 and the end of the side wall portion 22 (27).

[0057] This can prevent short circuits caused by contact between the conductive paths at a potential higher than the ground potential on the upper and lower surfaces of the circuit board 11 and the front ends of the side walls 22 ( 27 ) of the shielding cases 20 , 25 .

[0058] Furthermore, the capacitor 36 is accommodated between the second shielding case 25 and the second resin case 45 .

[0059] In this way, the second shielding case 25 and the electronic component 16 can be arranged in the gap between the circuit board 11 and the capacitor 36 .

[0060] <Other Implementation Methods>

[0061] The technology described in this specification is not limited to the embodiments described in the above description and drawings, and for example, the following embodiments are also included in the technical scope of the technology described in this specification.

[0062] (1) The electronic component 16 is mounted on the back side of the circuit board 11 (the shielding area A1 covered by the second shielding shell 25), but the present invention is not limited to this. The electronic component may not be mounted on the shielding area A1 on the back side of the circuit board 11, but only a conductive path may be arranged.

[0063] (2) The range of the shielding area A1 of the circuit board 11 covered by the first shielding case 20 and the second shielding case 25 is not limited to the configuration of the above embodiment. For example, one or both of the first shielding case 20 and the second shielding case 25 may cover the entire circuit board 11.

[0064] (3) The locked hole 24A of the first shielding case 20 is a through hole, but the present invention is not limited to this, and the protrusion 30 may be locked in a non-through locking recess.

[0065] (4) The first shielding shell 20 is provided with the locked hole 24A, and the second shielding shell 25 is provided with the locking pieces 29A and 29B. However, the present invention is not limited thereto. The first shielding shell 20 may be provided with a locking piece, and the second shielding shell 25 may be provided with a locked hole that is locked to the locking piece.

[0066] (5) The second shielding case 25 is provided with the fastening portion 28B connected to the ground potential, but the present invention is not limited thereto, and a fastening portion connected to the ground potential may be provided in the first shielding case 20. Furthermore, the second shielding case 25 is provided with the step portion 32, but the first shielding case 20 may also be provided with the step portion.

[0067] Description of symbols

[0068] 10: Electrical connection box

[0069] 11: Circuit board

[0070] 15-17: Electronic components

[0071] 20: First shielding shell

[0072] 22, 22: Side wall

[0073] 24: Stuck Department

[0074] 25: Second shielding shell

[0075] 26: Relative part

[0076] 27, 27: Side wall

[0077] 28B: Fastening part

[0078] 29A: First fixing piece

[0079] 29B: Second fixing piece

[0080] 30: protrusion

[0081] 32: Step

[0082] 36: Capacitor

[0083] 40: First resin shell

[0084] 45: Second resin shell

[0085] 47A, 47B: Boss part

[0086] 52: Screw

[0087] A1: Shielded area (area)

[0088] GP: Ground Pattern.

Claims

1. An electrical connection box, comprising: A circuit substrate having conductive paths and mounted with electronic components; A conductive first shielding shell covering one side of the circuit substrate; A conductive second shielding shell covers a side of the circuit substrate opposite to the one side; a first resin shell made of resin, covering the first shielding shell; and a second resin casing made of resin, covering the second shielding casing, The electronic components are multiple and include a high-noise component and a low-noise component having less noise than the high-noise component, and the first shielding shell and the second shielding shell cover the surface of the circuit substrate in a manner that includes a region where the high-noise component is mounted in a region smaller than the entire region of the circuit substrate. One of the first shielding shell and the second shielding shell has a plate-shaped locked portion, and the other of the first shielding shell and the second shielding shell has a first locking piece and a second locking piece for clamping the locked portion, the first locking piece and the second locking piece are alternately arranged in parallel along the locked portion, and a gap for clamping the locked portion is formed between the position of the first locking piece and the position of the second locking piece in a direction intersecting the locked portion, The conductive path includes a ground pattern connected to a ground potential, At least one of the first shielding shell and the second shielding shell includes a fastening portion that is screwed to the circuit board and connected to the ground pattern. When the first shielding housing and the second shielding housing are assembled, the locked portion contacts the first locking piece and the second locking piece, and one of the first shielding housing and the second shielding housing having the fastening portion electrically connects the other to the ground potential.

2. The electrical connection box according to claim 1, wherein: At least one of the first shielding casing and the second shielding casing includes the fastening portion and a facing portion that faces the circuit board with a gap therebetween, and a step portion is formed between the fastening portion and the facing portion.

3. The electrical connection box according to claim 1 or 2, wherein: At least one of the first shielding case and the second shielding case includes a side wall portion having a plate surface in a direction intersecting with a plate surface of the circuit substrate, and an end of the side wall portion on the circuit substrate side forms a gap with a surface of the circuit substrate.

4. The electrical connection box according to claim 1 or 2, wherein: A capacitor is accommodated between the second shielding case and the second resin case.

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