Power supply distribution box

Abstract

Disclosed is a power supply distribution box capable of distributing, with high space efficiency, power supply to each load via a fuse.　A power supply distribution box 10 is configured by including a first circuit component 22, a second circuit component 32, and jumper wires 34a, 34b. The first circuit component 22 has: a bus bar circuit 14 constituted by a plurality of bus bars 12a, 12b; power supply input units 16a, 16b connected to the upstream side of the bus bar circuit 14; a first printed board 18; and a semiconductor switch 20 mounted on the bus bar circuit 14 and the first printed board 18. The second circuit component 32 has: a second printed board 24; a semiconductor fuse 28 mounted on a conductive path 26 of the second printed circuit board 24; and an output part 30 connected to the conductive path 26 on the downstream side of the semiconductor fuse 28. The jumper wires 34a, 34b connect the bus bar 12a on the downstream side of the semiconductor switch 20 and the conductive path 26b on the upstream side of the semiconductor fuse 28.

Description

Power Distribution Box

[0001] The present disclosure relates to a power distribution box.

[0002] Conventionally, automobiles have been equipped with power distribution boxes such as relay boxes and junction boxes that distribute power from a battery or the like to various loads. For example, Patent Document 1 discloses a power distribution box that uses switching elements such as FETs instead of relays to perform on / off control of the power supply.

[0003] Japanese Patent Application Laid-Open No. 2020-22273

[0004] However, since the power distribution box in Patent Document 1 does not have a fuse function, when distributing power to each load via a fuse, it is necessary to connect to each load via a separate fuse box. This requires space for the separate fuse box and wiring to connect to the separate fuse box. In such cases, saving space has been an issue.

[0005] Therefore, a power distribution box is disclosed that enables space-efficient power distribution to each load via fuses.

[0006] The power distribution box of the present disclosure is configured to include a first circuit component, a second circuit component, and a jumper wire, wherein the first circuit component has a busbar circuit formed of a plurality of busbars, a power input section connected to the upstream side of the busbar circuit, a first printed circuit board, and a semiconductor switch mounted on the busbar circuit and the first printed circuit board, the second circuit component has a second printed circuit board, a semiconductor fuse mounted on a conductive path of the second printed circuit board, and an output section connected to the conductive path downstream of the semiconductor fuse, and the jumper wire connects the busbar downstream of the semiconductor switch to the conductive path upstream of the semiconductor fuse.

[0007] The power distribution box of the present disclosure enables space-efficient power distribution to each load via fuses.

[0008] FIG. 1 is a perspective view showing a power distribution box according to a first embodiment. FIG. 2 is a perspective view showing the power distribution box shown in FIG. 1 with the case removed. FIG. 3 is a perspective view showing a main body constituting the power distribution box shown in FIG. 2 from the rear side. FIG. 4 is a plan view of the main body of the power distribution box shown in FIG. 3. FIG. 5 is a side view of the main body of the power distribution box shown in FIG. 3. FIG. 6 is a longitudinal cross-sectional view of the power distribution box shown in FIG. 1, corresponding to the cross section VI-VI in FIG. 4. FIG. 7 is a longitudinal cross-sectional view of the power distribution box shown in FIG. 1, corresponding to the cross section VII-VII in FIG. 4. FIG. 8 is a perspective view showing a bus bar circuit constituting the power distribution box shown in FIG. 1. FIG. 9 is a perspective view showing a state in which a second printed circuit board is being placed on a resin plate of a first circuit component in the power distribution box shown in FIG. 1. FIG. 10 is a perspective view showing a state in which a first printed circuit board is attached across the bus bar circuit and the second printed circuit board after the state shown in FIG. 9 in the power distribution box shown in FIG. 1. FIG. 11 is a circuit diagram showing the electrical configuration of the power distribution box shown in FIG.

[0009] <Description of Embodiments of the Present Disclosure> First, embodiments of the present disclosure will be listed and described. The power distribution box of the present disclosure is: (1) a power distribution box including a first circuit component, a second circuit component, and a jumper wire, wherein the first circuit component includes a busbar circuit formed of a plurality of busbars, a power input unit connected to an upstream side of the busbar circuit, a first printed circuit board, and a semiconductor switch mounted on the busbar circuit and the first printed circuit board, the second circuit component includes a second printed circuit board, a semiconductor fuse mounted on a conductive path of the second printed circuit board, and an output unit connected to the conductive path downstream of the semiconductor fuse, and the jumper wire connects the busbar downstream of the semiconductor switch to the conductive path upstream of the semiconductor fuse.

[0010] According to this aspect of the power distribution box, the power distribution box includes a first circuit component having a semiconductor switch and a second circuit component having a semiconductor fuse. A bus bar downstream of the semiconductor switch is connected to a conductive path upstream of the semiconductor fuse by a jumper wire. As a result, in the first circuit component, current input from a power input unit connected to the upstream side of the bus bar circuit is output to the downstream bus bar via the semiconductor switch. The bus bar downstream of the semiconductor switch is connected to the conductive path upstream of the semiconductor fuse of the second circuit component by a jumper wire. Therefore, current output via the semiconductor switch is supplied to an output unit connected to the downstream conductive path via the semiconductor fuse of the second circuit component, and is then provided to each load. As described above, the power distribution box of this aspect includes a semiconductor fuse in addition to a semiconductor switch, so that power can be distributed to each load without the need for a separate fuse box. In particular, because the fuse function is realized by a semiconductor fuse mounted on the second printed circuit board, space can be saved compared to using a separate fuse box. Furthermore, since the first circuit component and the second circuit component can be connected simply by using a jumper wire that connects the bus bar on the downstream side of the semiconductor switch and the conductive path on the upstream side of the semiconductor fuse, the space required for wiring can be significantly reduced compared to conventional structures in which a wire harness or the like is routed to a separate fuse box. As a result, it is possible to provide a power distribution box that enables space-efficient power distribution to each load via fuses.

[0011] (2) In the above (1), it is preferable that the first circuit component includes a resin plate that arranges and holds the plurality of bus bars in a desired circuit shape, and the resin plate includes a mounting portion on which the second printed circuit board is placed. Because the plurality of bus bars are arranged in the desired circuit shape and integrated by the resin plate, assembly of the bus bar circuit can be simplified and the plurality of bus bars are easy to handle. Furthermore, because the resin plate has a mounting portion on which the second printed circuit board is placed, the first circuit component and the second circuit component can be assembled to each other using the resin plate, further improving handleability and achieving stable mutual connection.

[0012] (3) In the above (2), it is preferable that, with the second printed circuit board placed on the placement section, the bus bar downstream of the semiconductor switch and the conductive path upstream of the semiconductor fuse are positioned at a location where they can be connected by the jumper wire. By placing the second printed circuit board on the placement section provided on the resin plate, the bus bar downstream of the semiconductor switch and the conductive path upstream of the semiconductor fuse are positioned at a location where they can be connected by the jumper wire. This makes it possible to improve the fixation of the first circuit component and the second circuit component and the ease of connection by the placement section provided on the resin plate.

[0013] (4) In the above (3), it is preferable that, when the second printed circuit board is placed on the placement section, an upper surface of the bus bar downstream of the semiconductor switch and an upper surface of the conductive path upstream of the semiconductor fuse are positioned on the same plane. This makes it possible to easily and reliably mount various components, including jumper wires, on the first circuit component and the second circuit component in the same soldering process, thereby further improving workability.

[0014] (5) In any one of (2) to (4) above, the resin plate is preferably molded by inserting the bus bars into it, and the peripheral edges of the bus bars are provided with chamfered portions that reduce the thickness of the bus bars toward the outside of the bus bars. The chamfered portions are preferably covered by the resin plate, and portions of the bus bars on the surface located inside the chamfered portions are exposed from the resin plate. In the case where the bus bars are insert-molded from the resin plate, the chamfered portions can be provided on the peripheral edges of the bus bars so that the chamfered portions are covered by the resin plate. This effectively prevents or suppresses the bus bars from slipping out of the resin plate by the resin plate covering the chamfered portions. In addition, since portions of the bus bars on the surface located inside the chamfered portions are exposed from the resin plate, it is easy to connect leads of semiconductor switches, jumper wires, etc. to the bus bars.

[0015] (6) In any one of (1) to (5) above, it is preferable that the jumper wire is configured using a jumper bus bar, one end of the jumper bus bar is connected to the bus bar of the first circuit component, and the other end of the jumper bus bar is connected to the conductive path made of thick copper foil of the second circuit component. The jumper wire can be configured using a jumper bus bar to connect the bus bar of the first circuit component and the conductive path of the thick copper foil of the second circuit component. This enables a circuit connection that can handle large currents, and makes it easy to form a circuit that outputs large currents supplied from a semiconductor switch to a semiconductor fuse.

[0016] (7) In any one of (1) to (6) above, it is preferable that the power supply input unit includes a first power supply input unit to which power is supplied from a first battery and a second power supply input unit to which power is supplied from a second battery, and the first power supply input unit and the second power supply input unit are each connected to the output unit via the semiconductor switch and the semiconductor fuse. By providing the first power supply input unit and the second power supply input unit, if one of the power supplies fails, power is supplied from the other power supply, thereby making it possible to maintain safe driving, etc.

[0017] <Details of the embodiment of the present disclosure> Specific examples of the power distribution box of the present disclosure will be described below with reference to the drawings. Note that the present disclosure is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims.

[0018] First Embodiment A power distribution box 10 according to a first embodiment of the present disclosure will be described below with reference to FIGS. 1 to 11 . The power distribution box 10 is mounted, for example, on an electric vehicle or a hybrid vehicle and is disposed downstream of a battery (not shown) that serves as a power source. In the first embodiment, the power distribution box 10 has two power supply systems: one path for supplying power from a first battery (e.g., a low-voltage battery) (not shown) and one path for supplying power from a second battery (e.g., a high-voltage battery via a DC-DC converter) (not shown). Note that the power distribution box 10 can be positioned in any orientation within the vehicle. However, in the following description, the upper side will be referred to as the upper side in FIG. 5 , the lower side as the lower side in FIG. 5 , the left side as the lower side in FIG. 4 , the right side as the upper side in FIG. 4 , the front side as the right side in FIG. 4 , and the rear side as the left side in FIG. 4 . In addition, for multiple identical components, only some of the components will be designated by reference numerals, and the reference numerals for the other components will be omitted.

[0019] <Power Distribution Box 10> The power distribution box 10 includes a busbar circuit 14 (see FIG. 8 , etc.) formed by a plurality of busbars 12, a first circuit assembly 22 having a power input unit 16 connected upstream of the busbar circuit 14, a first printed circuit board 18, and semiconductor switches 20 mounted on the busbar circuit 14 and the first printed circuit board 18. The power distribution box 10 also includes a second circuit assembly 32 having a second printed circuit board 24, a semiconductor fuse 28 mounted on a conductive path 26 (see FIG. 11 ) of the second printed circuit board 24, and an output unit 30 connected to a conductive path 26 a downstream of the semiconductor fuse 28. The power distribution box 10 also includes a jumper wire 34 connecting the busbar 12 a downstream of the semiconductor switch 20 to the conductive path 26 b upstream of the semiconductor fuse 28. It should be noted that FIG. 11 shows a model of the electrical configuration of the power distribution box 10, and the number of semiconductor switches 20, semiconductor fuses 28, output sections 30, etc. shown in FIG. 11 does not necessarily match the numbers of those shown in FIGS. 1 to 10.

[0020] 2 and other figures, the first circuit component 22, the second circuit component 32, and the jumper wires 34 constitute a main body 36 of the power distribution box 10, and the main body 36 is housed in a case 38 to form the power distribution box 10. In particular, in the first embodiment, the case 38 is configured to include an upper case 40 and a lower case 42 that can be separated and fixed in the vertical direction. Specifically, the lower case 42 has a housing recess 44 that can house the main body 36, and an upper opening 46 of the lower case 42, in which the main body 36 is housed, is covered by the upper case 40, and the upper case 40 and the lower case 42 are fixed to each other to form the power distribution box 10.

[0021] <Busbar Circuit 14> As described above, the busbar circuit 14 is composed of a plurality of busbars 12. The busbar circuit 14 includes a busbar 12a downstream of the semiconductor switch 20 and a busbar 12b upstream of the semiconductor switch 20. In other words, the upstream busbar 12b and the downstream busbar 12a are electrically connected by the semiconductor switch 20. In the first embodiment, the upstream busbar 12b and the downstream busbar 12a are arranged spaced apart in the front-to-rear direction, and the upstream busbar 12b is located further rearward than the downstream busbar 12a. In particular, in the first embodiment, four upstream busbars 12b are provided spaced apart from each other in the left-to-right direction, and the downstream busbar 12a is located in front of the upstream busbars 12b.

[0022] Each of the bus bars 12a, 12b has a generally rectangular shape in a plan view and is made of a highly conductive metal such as copper or a copper alloy. The bus bars 12a, 12b have a larger left-right dimension than a front-rear dimension. In the first embodiment, each bus bar 12a, 12b has a chamfered portion 48 at its periphery (e.g., at its four corners). That is, at each chamfered portion 48, the thickness dimension A (see FIGS. 6 and 7 ) of each bus bar 12a, 12b gradually decreases outward. The downstream bus bar 12b also has a positioning recess 50 for positioning when attaching the first printed circuit board 18, as described below. In the first embodiment, the downstream bus bar 12a has two positioning recesses 50 spaced apart in the left-right direction. Each positioning recess 50 is formed as a circular through-hole that penetrates the downstream bus bar 12a in the thickness direction (up-down direction).

[0023] <Power Supply Input Unit 16> The power supply input unit 16 includes a first power supply input unit 16a that receives power from the first battery (e.g., a low-voltage battery) and a second power supply input unit 16b that receives power from the second battery (e.g., a high-voltage battery via a DC-DC converter). Each of these power supply input units 16a and 16b is connected to the upstream side of the bus bar circuit 14, specifically to the upstream bus bar 12b. In the first embodiment, as described above, four upstream bus bars 12b are provided spaced apart in the left-right direction. Of the two bus bars 12b in the center in the left-right direction, the left bus bar 12b is the first input bus bar 12c to which the first power supply input unit 16a is connected, and the right bus bar 12b is the second input bus bar 12d to which the second power supply input unit 16b is connected. The two bus bars 12b at both ends in the left and right direction are output bus bars 12e that are connected to an external load 86 as will be described later.

[0024] More specifically, each power input portion 16a, 16b is configured as a tab-shaped bus bar and protrudes upward from the rear end of each input bus bar 12c, 12d. The lower end of each power input portion 16a, 16b is provided with a plurality of bent legs 52 extending in the front-to-rear direction, including both forward-extending legs 52a and rear-extending legs 52b. The rearward-extending legs 52b of each power input portion 16a, 16b are engaged with engaging holes 82 provided in a resin plate 70 (described later) that holds each bus bar 12. The forward-extending legs 52a of each power input portion 16a, 16b are overlapped with and electrically connected to the input bus bars 12c, 12d.

[0025] <First Printed Circuit Board 18> In the first embodiment, the first printed circuit board 18 is configured as a thin-walled flexible printed circuit (FPC). As shown in FIG. 4 and other figures, the first printed circuit board 18 has a generally rectangular shape with a larger left-right dimension than a front-to-rear dimension in a plan view. An electrical circuit 54, as shown in FIG. 3 and other figures, is printed on the top surface of the first printed circuit board 18. The first printed circuit board 18 is disposed across the upstream bus bars 12b and the downstream bus bar 12a. That is, the rear portion of the first printed circuit board 18 is overlapped on the upstream bus bars 12b, and the front portion of the first printed circuit board 18 is overlapped on the downstream bus bar 12a. The semiconductor switch 20 is mounted on the first printed circuit board 18, and the semiconductor switch 20 is mounted on the bus bar circuit 14 and the first printed circuit board 18 as described above.

[0026] As will be described later, the semiconductor switch 20 is configured as a field effect transistor (FET) and has a source terminal 64, a drain terminal 66, and a control terminal 68. A substantially rectangular through-hole 56 is formed in the first printed circuit board 18 at a position corresponding to the source terminal 64 of the semiconductor switch 20, and the source terminal 64 of the semiconductor switch 20 mounted on the first printed circuit board 18 is electrically connected to each upstream bus bar 12b through the through-hole 56. Furthermore, a substantially rectangular through-hole 58 is formed in the first printed circuit board 18 at a position corresponding to the drain terminal 66 of the semiconductor switch 20, and the drain terminal 66 of the semiconductor switch 20 mounted on the first printed circuit board 18 is electrically connected to the downstream bus bar 12a through the through-hole 58. The control terminal 68 of the semiconductor switch 20 is electrically connected to the electrical circuit 54 on the first printed circuit board 18.

[0027] Furthermore, positioning recesses 60 are formed in the front portion of the first printed circuit board 18 at positions corresponding to the positioning recesses 50 formed in the downstream busbar 12b. That is, in the first embodiment, a pair of positioning recesses 60, 60 are formed in the front portion of the first printed circuit board 18, spaced apart from each other in the left-right direction. In particular, in the first embodiment, these positioning recesses 60 are formed as circular through-holes that penetrate the first printed circuit board 18 in the thickness direction (up-down direction). Therefore, when the first printed circuit board 18 is superimposed on and fixed to the busbars 12a, 12b, the busbars 12a, 12b and the first printed circuit board 18 are positioned using, for example, pins (not shown) inserted into the positioning recesses 50, 60 as guides. The method for fixing the busbars 12a, 12b to the first printed circuit board 18 is not limited, and the first printed circuit board 18 can be attached to the busbars 12a, 12b, for example, with adhesive tape (not shown).

[0028] Further, a forward extension portion 61 extending forward is provided in a longitudinal (left-right) intermediate portion of the first printed circuit board 18. The forward extension portions 61 are provided at two locations on the first printed circuit board 18 that are spaced apart from each other in the left-right direction, and each forward extension portion 61 has a predetermined left-right dimension. Ends of the electrical circuits 54 on the first printed circuit board 18 are provided in parallel in the left-right direction on each forward extension portion 61. The ends of the electrical circuits 54 opposite the side located on each forward extension portion 61 are electrically connected to connecting members 87 and control terminals 68 of the semiconductor switches 20, which will be described later. Each of these forward extension portions 61 has a predetermined forward extension amount, and when the main body 36 is assembled as described below, the front end of each forward extension portion 61 is arranged to overlap the rear end portion of the second printed circuit board 24.

[0029] <Semiconductor Switch 20> In the first embodiment, the semiconductor switch 20 is configured using a known FET, and therefore detailed description thereof will be omitted. However, the semiconductor switch 20 includes a main body 62 including a housing. The main body 62 is generally rectangular in plan view, and is provided with a source terminal 64, a drain terminal 66, and a control terminal 68 that protrude outward in the front-to-rear direction. Specifically, the source terminal 64 protrudes rearward from the main body 62, and multiple source terminals 64 are provided in parallel at a predetermined distance in the left-to-right direction. The drain terminal 66 is generally rectangular and plate-shaped, and is provided at the lower end of the main body 62, with the front end of the drain terminal 66 protruding forward from the main body 62. The control terminal 68 is provided in parallel with the multiple source terminals 64 in the left-to-right direction and protrudes rearward from the main body 62.

[0030] In particular, in the first embodiment, of the multiple terminals that protrude rearward from the main body portion 62 and are arranged in parallel in the left-right direction, the rightmost terminal is the control terminal 68, which is electrically connected to the electrical circuit 54 on the first printed circuit board 18 as described above. Furthermore, of the multiple terminals that protrude rearward from the main body portion 62 and are arranged in parallel in the left-right direction, the terminals other than the rightmost terminal are source terminals 64. Of these multiple source terminals 64, the source terminal 64a adjacent to the control terminal 68 (the rightmost source terminal 64a) is mounted in a non-conductive state on the first printed circuit board 18, thereby preventing the semiconductor switch 20 from being raised or tilted. The source terminals 64 other than the source terminal 64a adjacent to the control terminal 68 are overlapped and electrically connected to the upstream bus bars 12b through the through holes 56 as described above. The drain terminal 66 is overlapped and electrically connected to the downstream bus bar 12a through the through holes 58 as described above.

[0031] A plurality of semiconductor switches 20 having the above-described shape are provided on the first printed circuit board 18, and the plurality of semiconductor switches 20 are arranged at a predetermined distance apart in the left-right direction. In each of the plurality of semiconductor switches 20, the control terminal 68 is electrically connected to the electric circuit 54 on the first printed circuit board 18, and the plurality of source terminals 64 are electrically connected to the upstream bus bars 12b through the through holes 56 in the first printed circuit board 18. In addition, the drain terminal 66 of each semiconductor switch 20 is electrically connected to the downstream bus bar 12a through the through hole 58 in the first printed circuit board 18.

[0032] <First Circuit Component 22> As described above, the first circuit component 22 includes the busbar circuit 14 formed by the plurality of busbars 12 (upstream and downstream busbars 12b, 12a), the power supply input section 16 (first and second power supply input sections 16a, 16b), the first printed circuit board 18, and each semiconductor switch 20. In the first embodiment, the first circuit component 22 includes a resin plate 70 that arranges and holds the plurality of busbars 12 in a desired circuit shape. The resin plate 70 also includes a mounting section 72 on which the second printed circuit board 24 is mounted.

[0033] <Resin Plate 70> The resin plate 70 is made of a hard synthetic resin, and in Embodiment 1, the resin plate 70 is made of a thermoplastic resin. In particular, in Embodiment 1, when molding the resin plate 70, the bus bars 12 a, 12 b are inserted into a molding cavity, and the resin plate 70 is thereby formed as an integrally molded product including the bus bars 12 a, 12 b.

[0034] The resin plate 70 has holding portions 74 located on the outer periphery of each bus bar 12 a, 12 b to hold each bus bar 12 a, 12 b. In other words, the holding portions 74 have a plurality of accommodation recesses 76 formed therein to accommodate each bus bar 12 a, 12 b, and each bus bar 12 a, 12 b is accommodated in each accommodation recess 76, with the outer periphery of each bus bar 12 a, 12 b being fixed to the inner periphery of each accommodation recess 76. In the first embodiment, the bus bars 12 a, 12 b constituting the bus bar circuit 14 are oriented such that the left-right dimension is greater than the front-rear dimension in a plan view as a whole, and the holding portions 74 have a generally rectangular shape whose left-right dimension is greater than the front-rear dimension in a plan view.

[0035] 6 and 7 , in the first embodiment, when the bus bars 12 a, 12 b are fixed to the resin plate 70, the upper surfaces of the bus bars 12 a, 12 b are positioned slightly higher than the upper surfaces of the retaining portions 74. Therefore, in the resin plate 70 formed as an integrally molded product including the bus bars 12 a, 12 b, the upper surfaces of the bus bars 12 a, 12 b are exposed to the outside without being covered by the retaining portions 74. More specifically, as described above, the four corners of the bus bars 12 a, 12 b in the first embodiment are each provided with a chamfered portion 48. When the resin plate 70 is formed, the resin constituting the resin plate 70 is thicker above the chamfered portions 48 than in other portions. When the chamfered portions 48 are covered by the resin plate 70, the portions of the surfaces of the bus bars 12 a, 12 b that are located inside the chamfered portions 48 are exposed from the resin plate 70. For example, when each chamfered portion 48 is covered with the resin plate 70 , the surface (for example, the upper surface) of each bus bar 12 a , 12 b surrounded by each chamfered portion 48 is exposed from the resin plate 70 .

[0036] In the first embodiment, a through hole 78 is formed in the thickness direction (vertical direction) at the bottom of each accommodation recess 76 in the holding portion 74 of the resin plate 70. Each through hole 78 has a generally rectangular shape that is smaller than each accommodation recess 76 (each bus bar 12 a, 12 b) in a plan view. That is, when each bus bar 12 a, 12 b is accommodated in each accommodation recess 76 of the resin plate 70, the upper opening of each through hole 78 is covered by each bus bar 12 a, 12 b, and the lower surface of each bus bar 12 a, 12 b is exposed to the outside through each through hole 78.

[0037] Furthermore, circular positioning holes 80 that penetrate in the thickness direction (up and down direction) are formed at both ends in the length direction (front and back direction) of the holding portion 74. Then, locking holes 82 that penetrate in the thickness direction (up and down direction) are formed in the holding portion 74 behind the upstream bus bars 12b to lock the power input portions 16a, 16b connected to the bus bars 12b and the rearward-extending legs 52b of output terminals 84 (described later).

[0038] <Output Terminal 84> As described above, of the four upstream bus bars 12 b held by the holding portion 74, the two bus bars 12 b at the center in the left-right direction are the first and second input bus bars 12 c, 12 d to which the first and second power supply input portions 16 a, 16 b are connected, respectively. On the other hand, of the four upstream bus bars 12 b, the two bus bars 12 b at both ends in the left-right direction are output bus bars 12 e that are connected to an external load 86 (see FIG. 11 ) via output terminals 84. That is, in the bus bar circuit 14, the bus bars 12 b at both ends in the left-right direction on the upstream side (rear) are output bus bars 12 e, and the output terminals 84 are electrically connected to the output bus bars 12 e.

[0039] Each output terminal 84 has the same shape as each power input portion 16 a, 16 b and is configured as a tab-shaped bus bar. Each output terminal 84 protrudes upward from the rear end of each output bus bar 12 e, and a plurality of legs 52 that bend and extend in the front-to-rear direction are provided at the lower end of each output terminal 84. Each leg 52 a extending forward of each output terminal 84 overlaps and is electrically connected to each output bus bar 12 e, and each leg 52 b extending rearward is engaged with each engaging hole 82 in the resin plate 70.

[0040] The upstream bus bars 12b (first and second input bus bars 12c, 12d and each output bus bar 12e) are electrically connected to the electric circuit 54 on the first printed circuit board 18 via conductive connecting members 87. Each connecting member 87 is generally bridge-shaped, with one end connected to each upstream bus bar 12b and the other end connected to the electric circuit 54 on the first printed circuit board 18.

[0041] <Placement Portion 72> The placement portion 72 is integrally provided in front of the holding portion 74 having the above-described shape. In the first embodiment, the placement portion 72 includes a left-right extending portion 88 extending in the left-right direction along the holding portion 74 and a pair of arms 89, 89 protruding forward from both left and right ends of the left-right extending portion 88. Each arm 89 has a predetermined forward protrusion dimension, and the placement portion 72 as a whole has a generally U-shape that opens forward in a plan view. In particular, in the first embodiment, the left-right extending portion 88 has a longer length (left-right dimension) than the holding portion 74, and both left and right ends of the left-right extending portion 88 are positioned outward in the left-right direction relative to both left and right ends of the holding portion 74.

[0042] Furthermore, the front end portions of the left-right extending portions 88 are positioned lower than the upper surface of the holding portion 74 via a step-like portion 90 that extends vertically, and this front end portion and the upper surfaces of the left and right arm portions 89 form a mounting surface 92 that is generally U-shaped in plan view. That is, the entire mounting surface 92 is positioned lower than the upper surface of the holding portion 74, and the second printed circuit board 24 is placed on top of this mounting surface 92. The vertical dimension of the step-like portion 90 is equal to or slightly smaller than the thickness dimension A of the bus bars 12a, 12b described above and the thickness dimension B of the second printed circuit board 24 described below.

[0043] On the mounting surface 92 having a generally U-shape, upwardly protruding positioning protrusions 94 are formed in the left-right central portion of the left-right extending portion 88 and in the longitudinal (front-rear) central portion of each arm portion 89. The upward protrusion dimension of each positioning protrusion 94 is equal to or slightly smaller than the thickness dimension A of each bus bar 12a, 12b and the thickness dimension B of the second printed circuit board 24, and is equal to the vertical dimension of the stepped portion 90, for example. Therefore, the upper surface of the positioning protrusion 94 in the left-right central portion of the left-right extending portion 88 is at the same level as the rear end portions of the left-right extending portion 88 and the upper surfaces of the holding portions 74, and extends continuously from the rear end portions of the left-right extending portion 88.

[0044] <Second Printed Circuit Board 24> In the first embodiment, the second printed circuit board 24 is a PCB (printed circuit board) having a predetermined thickness B (see FIGS. 6 and 7 ). In particular, the second printed circuit board 24 is a rigid board. As shown in FIG. 4 and other figures, the second printed circuit board 24 has a left-right dimension in plan view that is approximately equal to the left-right extending portion 88 of the first circuit component 22, and is generally rectangular in shape with a larger left-right dimension than a front-rear dimension. Although not specifically shown, conductive paths 26 are printed on the top and bottom surfaces of the second printed circuit board 24. In particular, at least a portion of the conductive path 26 (the upstream conductive path 26b) to which a jumper wire 34 (jumper bus bar 34a) described later is connected is made of thick copper foil with a relatively large thickness.

[0045] As described above, the semiconductor fuse 28 is mounted on the second printed circuit board 24, and the conductive path 26 includes a conductive path 26b upstream of the semiconductor fuse 28 and a conductive path 26a downstream of the semiconductor fuse 28. The conductive path 26a downstream of the semiconductor fuse 28 is electrically connected to an external load 96 (see FIG. 11 ) via an output unit 30. The semiconductor fuse 28 and the output unit 30 are mounted on the upper surface of the second printed circuit board 24. A microcomputer 98 that controls the semiconductor switches 20 and the semiconductor fuse 28 is mounted on the lower surface of the second printed circuit board 24. Through holes (not shown) through which terminals 106 (described later) constituting the output unit 30 are inserted are formed in the second printed circuit board 24 at appropriate positions in the thickness direction (vertical direction) of the second printed circuit board 24.

[0046] The second printed circuit board 24 is provided with a plurality of screw insertion holes 102 through which screws 100 for fixing the second printed circuit board 24 to the lower case 42 are inserted, and each screw insertion hole 102 is formed to penetrate the second printed circuit board 24 in the thickness direction (vertical direction). Furthermore, positioning recesses 104 that open to the outer periphery and penetrate in the vertical direction are formed at a plurality of locations on the outer periphery of the second printed circuit board 24. In the first embodiment, one positioning recess 104 is formed on each of the front-rear and left-right sides of the second printed circuit board 24, and in particular, the rear and left-right positioning recesses 104 are formed at positions corresponding to the positioning protrusions 94 provided on the mounting surface 92 of the first circuit component 22.

[0047] Here, the thickness dimension B of the second printed circuit board 24 is set to be approximately equal to the thickness dimension A of each of the bus bars 12a, 12b, and when the second printed circuit board 24 is placed on the mounting surface 92 of the first circuit component 22, the upper surfaces of the bus bars 12a, 12b and the upper surface of the second printed circuit board 24 are at approximately the same position in the vertical direction. Specifically, when the second printed circuit board 24 is placed on the mounting portion 72, the bus bar 12a on the downstream side of the semiconductor switch 20 and the conductive path 26b on the upstream side of the semiconductor fuse 28 are positioned so that they can be connected by the jumper wire 34.

[0048] That is, for example, when the second printed circuit board 24 is placed on the mounting surface 92, the upper surfaces of the bus bars 12a, 12b are located within the thickness of the second printed circuit board 24 in the thickness direction (vertical direction) of the second printed circuit board 24. Furthermore, in this state, the upper surface of the second printed circuit board 24 is located within the thickness of the bus bars 12a, 12b in the thickness direction (vertical direction) of the bus bars 12a, 12b. In other words, the difference in height (vertical position) between the upper surfaces of the bus bars 12a, 12b and the upper surface of the second printed circuit board 24 is smaller than the thickness dimension A of the bus bars 12a, 12b and the thickness dimension B of the second printed circuit board 24. In the first embodiment, the upper surfaces of the bus bars 12a, 12b and the upper surface of the second printed circuit board 24 are flush with each other. Specifically, the upper surface of the downstream bus bar 12a and the upper surface of the upstream conductive path 26b are positioned flush with each other.

[0049] <Semiconductor fuse 28> In the first embodiment, the semiconductor fuse 28 is configured by a known IPD (Intelligent Power Device). Although detailed description is omitted, the semiconductor fuse 28 is a semiconductor element having a fuse function. That is, the semiconductor fuse 28 detects an abnormality such as an overcurrent and interrupts the current, and can also notify the microcomputer 98 or the like of this abnormality. The semiconductor fuse 28 is also self-resetting and does not need to be replaced after interrupting the current. The second circuit component 32 is provided with a plurality of semiconductor fuses 28, and each semiconductor fuse 28 is mounted at an appropriate position on the conductive path 26 of the second printed circuit board 24.

[0050] <Output Section 30> The output section 30 includes terminals 106 connected to the external load 96. The output section 30 is configured by inserting one or more of the terminals 106 vertically into and fixing them to support bases 108, and output sections 30 made up of these terminals 106 and support bases 108 are provided at multiple locations on the second printed circuit board 24. The lower end of each terminal 106 protruding downward from each support base 108 is inserted into a through-hole (not shown) in the second printed circuit board 24 and is electrically connected to a conductive path 26 provided on the second printed circuit board 24 via solder or the like (not shown).

[0051] <Second Circuit Component 32> The second circuit component 32 is configured by mounting the semiconductor fuses 28, the output sections 30, and the microcomputer 98 on the second printed circuit board 24. As described above, the rear end of the second printed circuit board 24 constituting the second circuit component 32 is placed on the mounting surface 92 of the mounting section 72 of the first circuit component 22. As a result, the downstream bus bar 12a of the first circuit component 22 and the second printed circuit board 24 of the second circuit component 32 are separated from each other in the front-to-rear direction, sandwiching the rear end portion of the left-to-right extending section 88 (the portion whose upper surface is at a height substantially equal to the upper surface of the holding section 74). Therefore, the bus bar circuit 14 constituting the first circuit component 22 is positioned so as not to overlap the second printed circuit board 24 constituting the second circuit component 32 when projected vertically. The first circuit component 22 and the second circuit component 32 are connected by a jumper wire 34.

[0052] <Jumper Wire 34> In the first embodiment, the jumper wire 34 includes a jumper bus bar 34a and a jumper connector 34b. The jumper bus bar 34a is formed by bending a strip of metal into a generally bridge shape. In the first embodiment, the jumper bus bar 34a is made of thick copper foil having a predetermined thickness. As shown in FIG. 6 and other figures, the jumper bus bar 34a is disposed so as to extend in the front-to-rear direction. One end (rear end) of the jumper bus bar 34a is connected to the downstream bus bar 12a in the first circuit component 22, and the other end (front end) of the jumper bus bar 34a is connected to the conductive path 26 on the top surface of the second printed circuit board 24. This electrically connects the downstream bus bar 12a and the conductive path 26 (particularly the upstream conductive path 26b) via the jumper bus bar 34a. In particular, since the jumper bus bar 34a and the portion of the conductive path 26b to which the jumper bus bar 34a is connected are made of thick copper foil with a relatively large thickness, the jumper bus bar 34a allows a relatively large current to flow between the downstream bus bar 12a and the upstream conductive path 26b.

[0053] As shown in Figures 3, 4, 7, etc., the jumper connector 34b has a plurality of metal conductive portions 110 bent into a generally bridge shape, and these plurality of conductive portions 110 are held by a single holding portion 112. In the first embodiment, the plurality of conductive portions 110 are arranged in parallel in the left-right direction, and both ends of each conductive portion 110 protrude outward in the front-rear direction from the holding portion 112. One end (rear end) of each conductive portion 110 is connected to an end of an electric circuit 54 arranged in parallel in the left-right direction on a forward extension portion 61 extending forward from the first printed circuit board 18. The other end (front end) of each conductive portion 110 is connected to the electric path 26 on the upper surface of the second printed circuit board 24. As a result, the electric circuit 54 on the first printed circuit board 18 and the electric path 26 (particularly the upstream electric path 26b) are electrically connected via the jumper connector 34b. Each conductive portion 110 is a smaller component than the above-mentioned jumper bus bar 34a, and the electrical circuit 54 on the first printed circuit board 18 to which the jumper connector 34b is connected is not as thick as each bus bar 12. Therefore, the jumper connector 34b allows a relatively small current to flow between the electrical circuit 54 on the first printed circuit board 18 and the upstream conductive path 26b.

[0054] That is, the jumper connector 34b is disposed at a location where the forward extending portion 61 is formed on the first printed circuit board 18, and electrically connects the electrical circuit 54 on the first printed circuit board 18 to the upstream conductive path 26b at two locations spaced apart in the left-right direction. The jumper bus bar 34a connects the downstream bus bar 12a to the upstream conductive path 26b at locations spaced apart in the left-right direction from the jumper connector 34b, and in the first embodiment, the jumper bus bar 34a is provided at three locations spaced apart in the left-right direction. Each jumper bus bar 34a electrically connects the downstream bus bar 12a to the upstream conductive path 26b by straddling the rear end portion of the left-right extending portion 88 located between the downstream bus bar 12a and the second printed circuit board 24. As a result, the first and second power supply input sections 16a, 16b provided in the first circuit component 22 are each connected to each semiconductor switch 20, and are connected to each output section 30 via each jumper wire 34a, 34b and each semiconductor fuse 28.

[0055] <Main Body 36> The main body 36 is configured by connecting the first circuit component 22 and the second circuit component 32 as described above with the jumper wires 34 (jumper bus bars 34a and jumper connectors 34b). That is, as described above, in the first circuit component 22 in the main body 36, the power input portions 16a, 16b and the output terminals 84 protrude upward from the downstream bus bars 12b. In addition, in the second circuit component 32 in the main body 36, the terminals 106 protrude upward from the support bases 108 of the output portions 30 arranged on the second printed circuit board 24. Meanwhile, in the first circuit component 22 in the main body 36, the lower surfaces of the bus bars 12a, 12b are exposed to the outside through the through holes 78 formed in the resin plate 70.

[0056] <Case 38> The main body 36 is accommodated in the case 38. In the first embodiment, as described above, the case 38 includes an upper case 40 and a lower case 42. The case 38 may be made of synthetic resin or metal, but in the first embodiment, the upper case 40 is made of synthetic resin and the lower case 42 is made of metal. The upper case 40 includes a cover plate 114 having a generally rectangular plate shape. The cover plate 114 has through-holes 116 (the through-holes 116 through which the output terminals 84 are inserted) that penetrate the cover plate 114 in the thickness direction (vertical direction) at positions corresponding to the power input ports 16a, 16b, the output terminals 84, and the output ports 30 (particularly the terminals 106) that protrude upward from the main body 36. (The through-holes 116 through which the output terminals 84 are inserted are shown in FIGS. 6 and 7.) A plurality of annular peripheral wall portions 118 that protrude upward are integrally formed on the outer periphery of each through window 116, and each power input portion 16a, 16b, each output terminal 84, and each terminal 106 that protrudes upward from the cover plate portion 114 protrudes into each annular peripheral wall portion 118.

[0057] Thus, four annular circumferential walls 118 are provided in the rear portion of the upper case 40, spaced apart from one another in the left-right direction, and the power input ports 16a, 16b are disposed on the inner peripheries of the two central annular walls 118 in the left-right direction. Thus, the two central annular walls 118 in the rear portion of the upper case 40 and the power input ports 16a, 16b form a connector-like power connection portion 119a to which the low-voltage and high-voltage batteries are electrically connected. Furthermore, output terminals 84 are disposed on the inner peripheries of the two annular walls 118 at both left-right ends in the rear portion of the upper case 40. Thus, the two annular walls 118 and the output terminals 84 form a connector-like load connection portion 119b to which the loads 86 are electrically connected. Furthermore, the terminals 106 of each output section 30 are disposed on the inner periphery of each annular peripheral wall section 118 in the front portion of the upper case 40. As a result, each annular peripheral wall section 118 and each terminal 106 constitutes a connector-like load connection section 119c that is electrically connected to each load 96. Note that the annular peripheral wall section 118 may be formed separately from the cover plate section 114 and subsequently fixed to the cover plate section 114.

[0058] In the first embodiment, the upper case 40 and the lower case 42 are fastened together with a plurality of bolts 120, and bolt insertion holes 122, through which the bolts 120 are inserted, are formed in the outer peripheral edge of the cover plate 114 so as to penetrate in the thickness direction (vertical direction). Furthermore, an annular groove 124 that opens downward and extends annularly is formed in the outer peripheral portion of the underside of the cover plate 114. An annular seal member 126 made of an elastic material such as rubber is disposed within this annular groove 124, and this seal member 126 is fixed to the inner surface of the annular groove 124 by adhesive or other means.

[0059] The lower case 42 has a generally rectangular box shape that opens upward as a whole, and as described above, has the accommodating recess 44 and the upper opening 46. That is, the lower case 42 includes a bottom wall 128 that is generally rectangular in plan view, and a lower peripheral wall 130 that protrudes upward from the outer periphery of the bottom wall 128. Therefore, the area surrounded by the bottom wall 128 and the lower peripheral wall 130 is the accommodating recess 44, and the upper opening 46 is defined at the upper end of the lower peripheral wall 130.

[0060] In the accommodating recess 44, a generally cylindrical second support portion 132 protruding upward from the bottom wall portion 128 is provided in a front portion of the accommodating recess 44 in which the second circuit component 32 is accommodated. The second support portion 132 is formed at a position corresponding to the screw insertion hole 102 in the second printed circuit board 24, and a plurality of second support portions 132 are formed in the front portion of the accommodating recess 44, spaced apart from one another in the circumferential direction. Furthermore, a screw fastening hole 134 into which each screw 100 is fastened is formed in the upper end of each second support portion 132. As a result, when the main body 36 is accommodated in the accommodating recess 44, the second printed circuit board 24 is placed and supported on each second support portion 132, and each screw 100 is fastened into the screw fastening hole 134 through the screw insertion hole 102. Furthermore, a positioning protrusion 136 that fits into the front positioning recess 104 of the second printed circuit board 24 is formed on the front wall that constitutes the lower peripheral wall 130 and protrudes rearward.

[0061] The rear portion of the accommodating recess 44, in which the first circuit component 22 is accommodated, has a bottom wall 128 positioned higher than the front portion of the accommodating recess 44. A first support portion 138 is provided in the rear portion of the accommodating recess 44, on which the resin plate 70 of the first circuit component 22 is placed and supported. That is, the first support portion 138 is formed by the rear portion of the bottom wall 128. Furthermore, the first support portion 138 has upper protrusions 140 formed at positions corresponding to the through holes 78 in the resin plate 70, each of which protrudes upward and fits into each of the through holes 78. When the main body 36 is accommodated in the accommodating recess 44, the upper protrusions 140 fit into the through holes 78 from below, supporting the bus bars 12a, 12b from below. Furthermore, a heat conduction sheet 142 having good thermal conductivity is provided at the overlapping portion between each upper protrusion 140 and each bus bar 12a, 12b, and in the first embodiment, each heat conduction sheet 142 is attached to the upper surface of each upper protrusion 140. Positioning protrusions 144 are formed at both left and right ends of the first support portion 138 at positions corresponding to the positioning holes 80 in the resin plate 70 and protrude upward. The positioning protrusions 144 are inserted into the positioning holes 80 when the resin plate 70 is overlapped on the first support portion 138.

[0062] Additionally, an annular protrusion 146 that protrudes upward and fits into the annular groove 124 in the upper case 40 is formed on the peripheral edge of the accommodation recess 44 (the inner peripheral edge of the lower peripheral wall 130). Furthermore, on the upper surface of the lower peripheral wall 130, bolt fastening holes 148 into which the bolts 120 are fastened are provided on the outer circumferential side of the annular protrusion 146. These bolt fastening holes 148 are formed at positions corresponding to the bolt insertion holes 122 in the upper case 40, and the plurality of bolt fastening holes 148 are formed spaced apart from one another in the circumferential direction.

[0063] When fixing the upper case 40 and lower case 42 together, the upper case 40 is placed over the lower case 42 from above with the main body 36 accommodated in the accommodation recess 44 of the lower case 42, and the bolts 120 are inserted into the bolt insertion holes 122 and fastened to the bolt fastening holes 148. As a result, the annular protrusion 146 of the lower case 42 is inserted into the annular groove 124 of the upper case 40, and the seal member 126 is pressed by the annular protrusion 146. As a result, the gap between the upper case 40 and the lower case 42 is liquid-tightly sealed by the seal member 126.

[0064] The shape of the underside of the lower case 42 is not limited, but for example, by forming a continuous uneven shape with parallel convex portions that protrude downward, it is possible to improve the heat dissipation properties of the lower case 42. Furthermore, legs 152 having bolt insertion holes 150 are formed integrally with the lower case 42, and the power distribution box 10 can be fixed to an appropriate position on the vehicle body by bolts (not shown) that are inserted into each bolt insertion hole 150.

[0065] <Assembly of the power distribution box 10> A specific example of a method for assembling the power distribution box 10 will now be described. Note that the method for assembling the power distribution box 10 is not limited to the embodiment described below.

[0066] First, as shown in FIG. 8 , the bus bars 12 a, 12 b are prepared. The bus bars 12 a, 12 b may be connected to each other by a metal piece (not shown) to prevent separation. This metal piece can be removed at any time. Next, the resin plate 70 is molded with the bus bars 12 a, 12 b set in the molding cavity, to integrally form the resin plate 70 including the bus bars 12 a, 12 b. Then, as shown in FIG. 9 , the rear end portion of the second printed circuit board 24 is placed on the mounting surface 92 of the mounting portion 72 of the resin plate 70. At this time, the positioning protrusions 94 on the mounting surface 92 fit into the positioning recesses 104 on the rear and left and right sides of the second printed circuit board 24, thereby aligning the second printed circuit board 24 and the resin plate 70 (the bus bars 12 a, 12 b) with each other. Then, by placing the resin plate 70 on the mounting surface 92, the upper surfaces of the bus bars 12a, 12b and the upper surface of the second printed circuit board 24 are positioned on the same plane. In particular, at this time, the positioning protrusions 94 on the mounting surface 92 are fitted into the positioning recesses 104 of the second printed circuit board 24 in a substantially press-fit state, which prevents misalignment between the resin plate 70 (the bus bars 12a, 12b) and the second printed circuit board 24.

[0067] 9 , the first printed circuit board 18 is then superimposed on each bus bar 12 a, 12 b and attached with adhesive tape as shown in FIG. 10 . This attachment of the first printed circuit board 18 is achieved by aligning the positioning recesses 50 on the downstream bus bar 12 a with the positioning recesses 60 on the first printed circuit board 18, as described above, and using, for example, pins (not shown). With the first printed circuit board 18 attached, the through hole 56 on the rear of the first printed circuit board 18 is positioned over the upstream bus bar 12 b, and the through hole 58 on the front of the first printed circuit board 18 is positioned over the downstream bus bar 12 a. Furthermore, the forward extensions 61 protruding forward from the first printed circuit board 18 are superimposed on the second printed circuit board 24, passing over the left-right extensions 88. In the first embodiment, the bus bar 12 a and the upper surface of the second printed circuit board 24 are located on the same plane, so that the occurrence of steps at each forward extension portion 61 of the first printed circuit board 18 is avoided.

[0068] As shown in FIG. 2 , the power input sections 16 a, 16 b, semiconductor switches 20, semiconductor fuses 28, output sections 30, jumper wires 34 (jumper bus bars 34 a, jumper connectors 34 b), and connecting members 87 are placed on the upper surfaces of the bus bars 12 a, 12 b, first printed circuit board 18, and second printed circuit board 24 in this state, and electrically connected by soldering. While the soldering method is not limited, reflow soldering is an example. This allows the soldering process for each component to be completed in one step. Furthermore, a microcomputer 98 is mounted on the lower surface of the second printed circuit board 24. The microcomputer 98 can be mounted on the lower surface of the second printed circuit board 24 at any time. As a result, the main body 36 is completed.

[0069] Heat-conducting sheets 142 are fixed in advance to the upper protrusions 140 of the lower case 42, and the main body 36 is accommodated in the accommodation recesses 44 of the lower case 42. Specifically, the first circuit component 22 is placed on the first support portions 138, and the second circuit component 32 is placed on the second support portions 132. At this time, the positioning protrusions 144 are inserted into the positioning holes 80 of the resin plate 70, and the positioning convex portions 94 are inserted into the front positioning recesses 104, thereby positioning the main body 36 and the lower case 42 relative to each other. Next, the screws 100 are inserted into the screw insertion holes 102 and fastened into the screw fastening holes 134 of the lower case 42, thereby fixing the main body 36 to the lower case 42. Thereafter, the upper case 40 is placed over the upper opening 46 of the lower case 42, and the bolts 120 are inserted into the bolt insertion holes 122 and fastened to the bolt fastening holes 148 of the lower case 42, thereby fixing the upper case 40 and the lower case 42 together. This completes the assembly of the power distribution box 10.

[0070] The power distribution box 10 manufactured in this manner is fixed to an appropriate position in the vehicle using, for example, bolts (not shown) inserted through the bolt insertion holes 150 of each leg 152. The low-voltage and high-voltage batteries are connected to the power supply connection portions 119a provided on the upper case 40 via connectors, and the loads 86, 96 are connected to the load connection portions 119b, 119c via connectors. This distributes power from the batteries to the loads 86, 96. This power distribution can be controlled by the semiconductor switches 20, the semiconductor fuses 28, and the microcomputer 98.

[0071] When a current is applied to each semiconductor switch 20, the semiconductor switch 20 generates heat, but each semiconductor switch 20 is in thermal contact with the metal lower case 42 via each thermal conduction sheet 142. This allows the heat generated by each semiconductor switch 20 to be dissipated to the outside via each thermal conduction sheet 142 and the lower case 42.

[0072] According to the power distribution box 10 of the first embodiment having the above-described structure, the first circuit component 22 provided with the semiconductor switches 20 having a switching function and the second circuit component 32 provided with the semiconductor fuses 28 having a fuse function are electrically connected via the jumper wires 34 (the jumper bus bars 34a and the jumper connectors 34b). By using semiconductor elements as the switches and fuses in this manner, the power distribution box 10 can be made smaller. In particular, since a plurality of the semiconductor switches 20 and the semiconductor fuses 28 can be mounted on the first printed circuit board 18 (the bus bars 12a and 12b) and the second printed circuit board 24, there is no need to connect them using a wire harness or the like, which achieves a smaller size and lighter weight. Furthermore, in embodiment 1, jumper wires 34 (jumper bus bars 34a and jumper connectors 34b) are employed, and the jumper wires 34a, 34b can electrically connect any position in the first circuit component 22 and the second circuit component 32, thereby improving design freedom.

[0073] The first circuit component 22 includes a resin plate 70 that arranges and holds the bus bars 12 a, 12 b in a desired circuit shape, and the resin plate 70 includes a mounting portion 72 on which the second printed circuit board 24 is mounted. The resin plate 70 allows the bus bars 12 a, 12 b to be handled as a unit, improving handleability. In addition, because the second printed circuit board 24 can be mounted on the resin plate 70, the resin plate 70 and the second printed circuit board 24 can also be handled as a unit, further improving handleability.

[0074] With the second printed circuit board 24 placed on the mounting portion 72, the downstream bus bar 12a and the upstream conductive path 26b are positioned so that they can be connected by the jumper wires 34a, 34b. In other words, by placing the second printed circuit board 24 on the mounting portion 72, the downstream bus bar 12a and the second printed circuit board 24 can be positioned relatively close to each other, facilitating connection by the jumper wires 34a, 34b.

[0075] In the first embodiment, the downstream busbar 12a and the upstream conductive path 26b are positioned on the same plane, meaning that the upper surfaces of the busbars 12a, 12b and the upper surface of the second printed circuit board 24 are positioned at the same height in the vertical direction (up and down direction). This allows the soldering of the electronic components mounted on the busbars 12a, 12b and the second printed circuit board 24, as well as the electrical connection of each member by solder, to be performed in a single reflow soldering process. As a result, the main body 36 can be assembled efficiently.

[0076] Resin plate 70 is molded with bus bars 12 a, 12 b inserted therein, and the peripheral edges of bus bars 12 a, 12 b are provided with chamfered portions 48. When resin plate 70 is molded, resin flows around to chamfered portions 48, thereby effectively preventing bus bars 12 a, 12 b from coming out of resin plate 70.

[0077] In the first embodiment, a jumper bus bar 34a is used as one of the jumper wires 34, with one end (rear end) of the jumper bus bar 34a connected to the downstream bus bar 12a of the first circuit component 22 and the other end (front end) of the jumper bus bar 34a connected to the conductive path 26 (upstream conductive path 26b) of the second circuit component 32. In particular, the downstream bus bar 12a and the jumper bus bar 34a both have a predetermined thickness, and the upstream conductive path 26b to which the jumper bus bar 34a is connected is made of thick copper foil. This allows a relatively large current to flow via the jumper bus bar 34a between the downstream bus bar 12a and the upstream conductive path 26b.

[0078] The power supply input unit 16 includes a first power supply input unit 16a to which power is supplied from a first battery (e.g., a low-voltage battery) and a second power supply input unit 16b to which power is supplied from a second battery (e.g., a high-voltage battery via a DC-DC converter). By supplying power from multiple power supplies in this manner, even if one power supply fails, power can be supplied from the other power supplies, and minimum functions such as vehicle running can be maintained even in the event of a vehicle malfunction.

[0079] <Modifications> Although the first embodiment has been described above in detail as a specific example of the present disclosure, the present disclosure is not limited to this specific description. Modifications, improvements, etc. within the scope of achieving the object of the present disclosure are included in the present disclosure. For example, the following modifications of the embodiment are also included in the technical scope of the present disclosure.

[0080] (1) In the above embodiment, the second printed circuit board 24 is placed on the mounting portion 72 of the resin plate 70, but the present invention is not limited to this. For example, the first circuit component and the second circuit component may be disposed in the housing recess of the lower case, spaced apart from each other in the front-rear direction, left-right direction, or up-down direction, and the first circuit component and the second circuit component may be connected by a jumper wire.

[0081] Furthermore, even when the second printed circuit board is placed on the mounting portion on the resin plate, the upper surfaces of the bus bars and the upper surface of the second printed circuit board may be at different heights. However, it is preferable that the upper surfaces of the bus bars and the upper surface of the second printed circuit board are relatively close to each other, which allows the height dimension (vertical dimension) of the main body, and therefore the power distribution box, to be kept relatively small.

[0082] (2) In the above embodiment, the resin constituting the resin plate 70 is a thermoplastic resin, but it may be a thermosetting resin. When the resin constituting the resin plate is a thermosetting resin, the resin plate is prevented from becoming soft due to heat generated by the semiconductor switch, and therefore, chamfered portions may not be provided on the periphery of each bus bar.

[0083] (3) In the above embodiment, the power distribution box has a first power input section 16a and a second power input section 16b, and power is supplied from two systems. However, this is not limited to this configuration, and the power distribution box according to the present disclosure may have only one power input section.

[0084] (4) In the above embodiment, the second printed circuit board 24 is placed on the mounting portion 72 of the resin plate 70, and then the first printed circuit board 18 is attached across the bus bars 12 a, 12 b and the second printed circuit board 24. However, this is not limited to this example. For example, after forming the resin plate, the first printed circuit board may be attached across the bus bars, and then the second printed circuit board may be placed on the mounting portion of the resin plate. In this case, the first printed circuit board 18 in the above embodiment is provided with the forward extension portion 61 that protrudes forward so as to extend across the second printed circuit board 24. However, the forward extension portion may be bent, curved, or pushed upward when the second printed circuit board is placed on the mounting portion. Note that, although the above embodiment describes the first printed circuit board 18 as an FPC, it may be a rigid board, and the first printed circuit board according to the present disclosure may not be provided with a forward extension portion.

[0085] (5) In the above embodiment, the chamfered portions 48 are provided at the four corners of each of the bus bars 12 a, 12 b. However, the positions and number of the chamfered portions 48 are not limited to those in the above embodiment, as long as they are provided at the periphery of each of the bus bars 12 a, 12 b. For example, the chamfered portions 48 may be provided at only two diagonal corners of the four corners of each of the bus bars 12 a, 12 b.

[0086] 10 Power distribution box 12 Bus bar 12a Bus bar downstream of semiconductor switch 12b Bus bar upstream of semiconductor switch 12c First input bus bar 12d Second input bus bar 12e Output bus bar 14 Bus bar circuit 16 Power input section 16a First power input section 16b Second power input section 18 First printed circuit board 20 Semiconductor switch 22 First circuit component 24 Second printed circuit board 26 Conductive path 26a Conductive path downstream of semiconductor fuse 26b Conductive path upstream of semiconductor fuse 28 Semiconductor fuse 30 Output section 32 Second circuit component 34 Jumper wire 34a Jumper bus bar 34b Jumper connector 36 Main body 38 Case 40 Upper case 42 Lower case 44 Housing recess 46 Upper opening 48 Chamfered portion 50 Positioning recess 52 Leg 52a Leg extending forward 52b Leg extending rearward 54 Electric circuit 56, 58 Through hole 60 Positioning recess 61 Forward extending portion 62 Main body portion 64 Source terminal 64a Source terminal adjacent to control terminal 66 Drain terminal 68 Control terminal 70 Resin plate 72 Placement portion 74 Holding portion 76 Housing recess 78 Through hole 80 Positioning hole 82 Locking hole 84 Output terminal 86 Load 87 Connection member 88 Left-right extending portion 89 Arm portion 90 Step-shaped portion 92 Placement surface 94 Positioning protrusion 96 Load 98 Microcomputer 100 Screw 102 Screw insertion hole 104 Positioning recess 106 Terminal 108 Support base DESCRIPTION OF SYMBOLS 110 Conductive portion 112 Holding portion 114 Cover plate portion 116 Through window 118 Annular peripheral wall portion 119a Power supply connection portion 119b, 119c Load connection portion 120 Bolt 122 Bolt insertion hole 124 Annular groove 126 Sealing member 128 Bottom wall portion 130 Lower peripheral wall portion 132 Second support portion 134 Screw fastening hole 136 Positioning protrusion 138 First support portion 140 Upward protrusion 142 Heat conduction sheet 144 Positioning protrusion 146 Annular protrusion 148 Bolt fastening hole 150 Bolt insertion hole 152 Leg portion

Claims

1. A power distribution box comprising a first circuit structure, a second circuit structure, and jumper wires, wherein the first circuit structure includes a bus bar circuit composed of a plurality of bus bars, a power input part connected to the upstream side of the bus bar circuit, a first printed circuit board, a bus bar circuit, and a semiconductor switch mounted on the first printed circuit board; the second circuit structure includes a second printed circuit board, a semiconductor fuse mounted on the conductive path of the second printed circuit board, and an output part connected to the conductive path on the downstream side of the semiconductor fuse; and the jumper wires connect the bus bar on the downstream side of the semiconductor switch and the conductive path on the upstream side of the semiconductor fuse.

2. The power distribution box according to claim 1, wherein the first circuit structure includes a resin plate that arranges and holds the plurality of bus bars in a desired circuit shape, and the resin plate includes a mounting part on which the second printed circuit board is mounted.

3. The power distribution box according to claim 2, wherein, with the second printed circuit board mounted on the mounting part, the bus bar on the downstream side of the semiconductor switch and the conductive path on the upstream side of the semiconductor fuse are positioned at positions where they can be connected by the jumper wires.

4. The power distribution box according to claim 3, wherein, with the second printed circuit board mounted on the mounting part, the upper surface of the bus bar on the downstream side of the semiconductor switch and the upper surface of the conductive path on the upstream side of the semiconductor fuse are positioned on the same plane.

5. The power distribution box according to any one of claims 2 to 4, wherein the resin plate is formed by insert molding with the plurality of bus bars, and a chamfered part that reduces the thickness dimension of the bus bar as it goes outward is provided at the peripheral edge of the bus bar, and the chamfered part is covered with the resin plate and a part of the bus bar surface located inside the chamfered part is exposed from the resin plate.

6. The power distribution box according to any one of claims 1 to 4, wherein the jumper wires are constituted by using jumper bus bars, one end of the jumper bus bar is connected to the bus bar of the first circuit structure, and the other end of the jumper bus bar is connected to the conductive path made of thick copper foil of the second circuit structure.

7. The power input section includes a first power input section to which power is supplied from the first battery and a second power input section to which power is supplied from the second battery, and each of the first power input section and the second power input section is connected to the output section via the semiconductor switch and the semiconductor fuse. The power distribution box according to any one of claims 1 to 4.