Electrical junction box

Abstract

Disclosed is an electrical junction box that can be miniaturized in the X and Y directions of a case body.　An electrical junction box 10 comprises: a case body 12; a relay terminal 14; bus bar storage parts 42a-42c, 44 that store a plurality of bus bars 16a-16k; upper-side component mounting parts 59, 72a-72d, 74 to which upper-side components 18, 20 are mounted, the upper-side components 18, 20 being incorporated from above and connected to the bus bars 16a-16k; and lower-side component mounting parts 36a-36d to which lower-side components 22, 24, 26, 28 are mounted, the lower-side components 22, 24, 26, 28 being incorporated from below and connected to the bus bars 16a-16k. The upper-side component mounting parts 59, 72a -72d and the lower-side component mounting parts 36a-36d are arranged so as to be overlapping in the vertical direction, and the bus bars 16a-16k and tab terminals 30 of the lower-side components 22, 24, 26, 28 are connected to the relay terminal 14, and thereby the lower-side components 22, 24, 26, 28 and the bus bars 16a-16g are conductively connected.

Description

Electrical junction box

[0001] The present disclosure relates to an electrical junction box.

[0002] Patent Document 1 discloses an electrical junction box (junction board) that forms part of a power supply device mounted on a vehicle and connects and disconnects a battery and a load. In this electrical junction box, multiple bus bars that form electrical paths are attached to a synthetic resin case body, and multiple electrical components such as contactors and fuses are attached to multiple component housings protruding from the top surface of the case body and connected to the bus bars. Furthermore, the bus bars are provided with external connection portions to which external current-carrying members such as wire harnesses are connected. The external connection portions also need to be located on the top surface of the case body so that the external current-carrying members can be fastened to the external connection portions.

[0003] Japanese Patent Application Laid-Open No. 2020-195235

[0004] Recently, with the trend toward larger currents in vehicles and higher density of on-board components, there has been a demand for smaller electrical junction boxes. However, in the electrical junction box described in Patent Document 1, multiple component accommodating sections and external busbar connection sections are provided at multiple locations on the top surface of the case body, spaced apart from one another, so that electrical components and external current-carrying members can be installed from above. Therefore, there is a limit to how much the size can be reduced in directions (X and Y directions) perpendicular to the vertical direction (Z direction) of the case body.

[0005] Therefore, an electrical junction box is disclosed that can reduce the size of the case body in the X and Y directions.

[0006] The electrical junction box according to the present disclosure comprises a case body, an intermediate terminal accommodating portion having upper and lower openings that open upward and downward to the case body and that accommodates an intermediate terminal inserted through the upper opening and assembled thereto, a busbar accommodating portion that opens upward to the case body and accommodates a plurality of busbars that are assembled from above and form an electrical path, an upper component mounting portion that opens upward to the case body and accommodates upper components that are assembled from above and connected to the busbar, and a lower component mounting portion that opens downward to the case body and accommodates lower components that are assembled from below and connected to the busbar, wherein the upper component mounting portion and the lower component mounting portion are arranged to overlap in the vertical direction of the case body, and portions of the busbars are connected to the intermediate terminals, and the lower components have tab terminals that are inserted through the lower openings of the intermediate terminal accommodating portion and connected to the intermediate terminals, thereby electrically connecting the lower components and the busbars.

[0007] According to the electrical junction box of the present disclosure, the size of the case body can be reduced in the X and Y directions.

[0008] Fig. 1 is an upper perspective view showing an electrical junction box according to a first embodiment. Fig. 2 is a lower perspective view of the electrical junction box shown in Fig. 1. Fig. 3 is a perspective view showing a state in which a case body and an upper cover have been removed from the electrical junction box shown in Fig. 1. Fig. 4 is a plan view of the electrical junction box shown in Fig. 1. Fig. 5 is a cross-sectional view taken along V-V in Fig. 4. Fig. 6 is a cross-sectional view taken along VI-VI in Fig. 4. Fig. 7 is an exploded perspective view of the electrical junction box shown in Fig. 1. Fig. 8 is a partially enlarged perspective view of the upper cover of the electrical junction box shown in Fig. 1, viewed from below.

[0009] <Description of Embodiments of the Present Disclosure> First, embodiments of the present disclosure will be listed and described. The electrical connection box of the present disclosure comprises: (1) a case body; a relay terminal accommodating section having upper and lower openings that open upward and downward to the case body and that accommodates a relay terminal inserted through the upper opening and assembled; a bus bar accommodating section that opens upward to the case body and accommodates a plurality of bus bars assembled from above to form an electrical path; an upper component mounting section that opens upward to the case body and to which upper components that are assembled from above and connected to the bus bar are attached; and a lower component mounting section that opens downward to which lower components that are assembled from below and connected to the bus bar are attached, wherein the upper component mounting section and the lower component mounting section are arranged to overlap in the vertical direction of the case body, and a portion of the bus bar is connected to the relay terminal, and the lower component has a tab terminal that is inserted through the lower opening of the relay terminal accommodating section and connected to the relay terminal, thereby electrically connecting the lower component and the bus bar.

[0010] According to this aspect of the electrical junction box, in addition to an upper component mounting portion that opens upward on the case body, the case body has a lower component mounting portion that opens downward on the case body, and these components are arranged to overlap in the vertical direction of the case body. This eliminates the need to space the upper and lower component mounting portions apart from each other in the X and Y directions, which are perpendicular to the vertical direction (Z direction) of the case, thereby enabling the case body to be miniaturized in the X and Y directions. In particular, a lower component having a tab terminal is mounted on the lower component mounting portion, and the tab terminal of the lower component is inserted into the lower opening of the relay terminal housing and connected to the relay terminal, thereby electrically connecting the lower component to the bus bar. This allows the lower component to be electrically connected to the bus bar housed in the case body without having to be assembled from above the case body. As a result, the lower component mounting portion can be arranged to overlap the upper component mounting portion in the vertical direction of the case body, enabling the case body to be miniaturized in the X and Y directions. Furthermore, since the tab terminals of the lower component can be connected to the bus bar via the relay terminals accommodated in the relay terminal accommodating sections of the case body, even if it were possible to arrange the upper component mounting sections one on top of the other in the vertical direction, there is an additional advantage that the length of the bus bar can be reduced.

[0011] (2) In the above (1), it is preferable that the upper component mounting portion includes an external conductor fastening portion that holds the external connection portion provided on the bus bar and allows the external current-carrying member to be fastened to the external connection portion from above. This is because, when fastening the external current-carrying member to the external connection portion provided on the bus bar, it is desirable for an operator to fasten the external current-carrying member to the external connection portion from above, for ease of operation. Even when such an external conductor fastening portion is provided as the upper component mounting portion, it can be provided so as to overlap above the lower component mounting portion in the up-down direction of the case body, thereby enabling the case body to be made smaller in the X and Y directions.

[0012] (3) In the above (2), it is preferable that a positive-side circuit is provided at one end of the case body, a negative-side circuit is provided at the other end of the case body, and the outer conductor fastening portion is provided in the central portion of the case body, because this allows the routing length of the busbar to be shorter than when the outer conductor fastening portion is provided on the periphery of the case body.

[0013] (4) In any one of (1) to (3) above, it is preferable that the upper component mounting portion includes an electric component fastening portion that holds an electric component including a fastening terminal that is bolted to a bolt fastening portion provided on the bus bar and allows the fastening terminal to be bolted to the bolt fastening portion from above. This is because, from the standpoint of workability, it is desirable to fasten an electric component including a fastening terminal that is bolted to a bolt fastening portion of the bus bar from above the case body. Even when such an electric component fastening portion is provided as the upper component mounting portion, it can be provided so as to overlap above the lower component mounting portion in the up-down direction of the case body, thereby enabling the case body to be made smaller in the X and Y directions.

[0014] (5) In any one of (1) to (4) above, it is preferable that the lower component mounting portion includes a plurality of the lower component mounting portions arranged to overlap in the vertical direction. This is because, when a plurality of lower component mounting portions are provided, arranging them to overlap in the vertical direction allows for further miniaturization of the case body in the X and Y directions. For example, when two lower component mounting portions arranged to overlap in the vertical direction are provided, the positions of the tab terminals of one lower component and the other lower component to be mounted thereon can be arranged to overlap in the vertical direction, for example.

[0015] (6) In any one of the above (1) to (5), it is preferable that the lower-side component mounting portion has a locking portion that engages with the lower-side component to keep the lower-side component connected to the bus bar and prevent the lower-side component from falling off the lower-side component mounting portion, because this can prevent the lower-side component from unexpectedly coming off the lower-side component mounting portion due to vibrations during transportation or loading of the electrical junction box.

[0016] (7) In any one of (1) to (6) above, it is preferable that the connector assembly further includes an upper cover covering an upper surface of the case body, the upper cover having a connector mounting portion opening upward, tab insertion holes formed through a bottom wall of the connector mounting portion, and a guide tube portion projecting downward around the connector mounting portion, the bus bar having connection tabs inserted through the tab insertion holes of the connector mounting portion and positioned on the connector mounting portion, the case body having connection tab mounting portions formed on the upper surface and positioning protrusions projecting upward around the connection tab mounting portions, and when assembling the upper cover to the case body, the positioning protrusions are inserted into the guide tube portion before the connection tabs are inserted through the tab insertion holes, thereby positioning the connection tabs in the tab insertion holes. Covering the upper surface of the case body with the upper cover makes it possible to prevent components from unexpectedly coming off the case body and ensure electrical insulation. In particular, even when a connector mounting portion to which an external connector is attached is provided on the upper cover, the positioning protrusion of the case body can be inserted into the guide tube portion of the upper cover to pre-position the tab insertion hole of the connector mounting portion and the connection tab provided on the bus bar protruding from the case body side, thereby enabling the upper cover to be assembled to the case body with good workability.

[0017] <Details of the Embodiments of the Present Disclosure> Specific examples of the electrical junction 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 An electrical junction box 10 according to a first embodiment of the present disclosure will be described below with reference to FIGS. 1 to 8 . The electrical junction box 10 is connected between an on-board power supply and a load, and is mounted, for example, inside a battery pack in an electric vehicle or hybrid vehicle. In the first embodiment, the electrical junction box 10 is connected between a battery (not shown) and an inverter (not shown), which is an example of a load. Note that the electrical junction box 10 can be positioned in any orientation within the vehicle. However, in the following description based on FIGS. 1 to 8 , the up-down direction of the electrical junction box 10 in FIG. 1 and the up-down direction of the case body 12 in FIG. 7 are referred to as the up-down direction or Z direction, the left-right direction of the electrical junction box 10 in FIG. 1 and the left-right direction of the case body 12 in FIG. 7 are referred to as the left-right direction or X direction, and the front-rear direction of the electrical junction box 10 in FIG. 1 and the front-rear direction of the case body 12 in FIG. 7 are referred to as the front-rear direction or Y direction. Furthermore, in some cases, when multiple identical components are used, only some of the components will be designated by reference numerals, and the reference numerals may be omitted for other components.

[0019] 7 , the electrical junction box 10 includes a case body 12, a plurality of relay terminals 14, and a plurality of bus bars 16 a to 16 k that are attached to the case body 12 from above. The relay terminals 14 and the bus bars 16 a to 16 k are formed by stamping a metal plate, and some of the bus bars 16 a to 16 k are connected to the relay terminals 14 to form electrical paths. The electrical junction box 10 also includes a fuse 18 and a current sensor 20 as upper components that are attached to the case body 12 from above and connected to the bus bars 16 d to 16 g, and a positive main contactor 22, a negative main contactor 24, a pre-charge contactor 26, and a pre-charge resistor 28 as lower components that are attached to the case body 12 from below and connected to the bus bars 16 a to 16 g. The positive main contactor 22, the negative main contactor 24, the pre-charge contactor 26, and the pre-charge resistor 28 each have a tab terminal 30, and the tab terminals 30 are connected to the relay terminals 14, thereby electrically connecting the positive main contactor 22, the negative main contactor 24, the pre-charge contactor 26, and the pre-charge resistor 28 to the bus bars 16a to 16g via the relay terminals 14. The electrical junction box 10 further has an upper cover 31 made of an insulating material that covers the top surface of the case body 12.

[0020] <Case Body 12 / Lower-Side Component Mounting Portions 36a-36d> The case body 12 is formed of an insulating material such as synthetic resin and has an overall rectangular block shape that is elongated in the X direction. More specifically, the case body 12 includes a substantially rectangular base plate 32 and multiple support legs 34a-34c that protrude upward from the top surface of the base plate 32. As shown in FIG. 7 , support leg 34a is located on the left side of the case body 12 in the left-right direction (X direction), support leg 34c is located on the right side, and support leg 34b is located therebetween. Furthermore, the case body 12 includes lower-side component mounting portions 36a-36d that protrude downward from the bottom surface of the base plate 32 in a frame-like shape and open downward toward the bottom of the case body 12 (see FIG. 5 ). The lower components, i.e., the positive main contactor 22, the negative main contactor 24, the pre-charge contactor 26, and the pre-charge resistor 28, are mounted on the lower component mounting portions 36a to 36d. The four corners of the base plate portion 32 are provided with bolt fixing portions 40 to which fastening bolts 38 are attached, so that the electrical junction box 10 can be fastened to the housing of a battery pack (not shown) or the like.

[0021] 7, the protruding end surfaces of the support legs 34a to 34c are provided with a plurality of busbar accommodating sections 42a to 42c, which are partitioned by ribs protruding from appropriate positions on the periphery. The upper surface of the base plate 32 is also provided with a plurality of busbar accommodating sections 44, which are partitioned by ribs and grooves protruding from appropriate positions. These busbar accommodating sections 42a to 42c and busbar accommodating section 44 are all open upward and are designed to accommodate the busbars 16a to 16k that are assembled from above.

[0022] 5 and 6 , in the region of the base plate portion 32 that forms the bottom wall of the lower component mounting portions 36a to 36d, relay terminal housings 45 are provided that house cylindrical relay terminals 14, respectively, at positions facing the tab terminals 30 of the lower components to be mounted, namely, the positive main contactor 22, the negative main contactor 24, the pre-charge contactor 26, and the pre-charge resistor 28. Each relay terminal housing 45 has an upper opening 46 that opens upward in the case body 12 and a lower opening 48 that opens downward. The upper opening 46 has a size that allows the relay terminal 14 to be inserted therethrough, so that the relay terminal 14 can be inserted through the upper opening 46 and assembled to the relay terminal housing 45. The lower opening 48 has a size that does not allow the relay terminal 14 to be inserted therethrough but allows the tab terminal 30 to be inserted therethrough. Therefore, the tab terminals 30 of the positive main contactor 22 , the negative main contactor 24 , the pre-charge contactor 26 , and the pre-charge resistor 28 are inserted through the lower opening 48 and connected to the relay terminal 14 .

[0023] Furthermore, connection portions 50 formed from parts of the bus bars 16a to 16g are inserted through the upper openings 46 of the respective relay terminal accommodating portions 45 and connected to the relay terminals 14. As a result, the positive main contactor 22, the negative main contactor 24, the pre-charge contactor 26, and the pre-charge resistor 28 mounted in the lower component mounting portions 36a to 36d, respectively, are electrically connected to the bus bars 16a to 16g via the relay terminals 14.

[0024] 3 and 7 , the bus bars 16a, 16b, and 16c form an input / output circuit to the positive main contactor 22 and a precharge circuit that bypasses the positive main contactor 22. One end of the bus bar 16a is provided with an input-side external connection portion 52a. A connection portion 50a protrudes from the downwardly extending portion of the external connection portion 52a and is connected to the input-side tab terminal 30 of the positive main contactor 22 via the relay terminal 14. The other end of the bus bar 16a, extending toward the precharge resistor 28, is provided with a downwardly protruding connection portion 50b and is connected to the input-side tab terminal 30 of the precharge resistor 28 via the relay terminal 14. The bus bar 16b has a lower connection portion 50c connected to the output-side tab terminal 30 of the precharge resistor 28 via the relay terminal 14, and an upper connection portion 50d connected to the input-side tab terminal 30 of the precharge contactor 26 via the relay terminal 14. The tab terminal 30 on the output side of the precharge contactor 26 is connected via the relay terminal 14 to a connection portion 50e provided at the end of the bus bar 16c on the precharge contactor 26 side. The other end of the bus bar 16c is provided with an output side external connection portion 52b arranged alongside the input side external connection portion 52a. The bus bar 16c has a connection portion 50f protruding from a portion extending downward from the external connection portion 52b, and is connected via the relay terminal 14 to the tab terminal 30 on the output side of the positive side main contactor 22.

[0025] <Busbars 16d-16g> As shown in FIGS. 3 and 7 , busbars 16d, 16e, 16f, and 16g form an input / output circuit to the negative-side main contactor 24. One end of busbar 16d is provided with an input-side external connection portion 52c. The other end of busbar 16d is connected to an input terminal 56 (see FIG. 4 ) of current sensor 20 at the rear right side of FIGS. 3 and 7 by bolt 57. An output terminal 58 of current sensor 20 is connected to one end 60 of busbar 16e by bolt 57. A current sensor mounting portion 59 serving as an upper component mounting portion is provided at the right end of the base plate portion 32 of the case body 12, opening upward. A nut 61 for fastening the bolt 57 is housed at the bottom of the current sensor mounting portion 59. The busbar 16d and the input terminal 56, and the busbar 16e and the output terminal 58 are clamped between the bolt 57 and the nut 61 so that electricity can flow between them. A connection portion 50g extending downward is provided at the other end of the busbar 16e and is connected to the input-side tab terminal 30 of the negative main contactor 24 via the relay terminal 14. The output-side tab terminal 30 of the negative main contactor 24 is connected to a connection portion 50h provided at one end of the busbar 16f via the relay terminal 14. A bolt fastening portion 62a is provided at the other end of the busbar 16f and is connected to an input-side fastening terminal portion 66a provided on the fuse 18 by fastening with a fastening bolt 68. An output-side fastening terminal portion 66b of the fuse 18 is connected to a bolt fastening portion 62b provided at one end of the busbar 16g by fastening with a fastening bolt 68. An output-side external connection portion 52d is provided at the other end of the busbar 16g.

[0026] <Busbars 16i to 16k> The busbars 16i to 16k constitute a control circuit that controls the opening and closing of the positive main contactor 22, the negative main contactor 24, and the precharge contactor 26. The busbars 16i to 16k are narrower than the busbars 16a to 16h. A connection tab 70 is provided at one end of each of the busbars 16i to 16k. The connection tab 70 is inserted into a tab insertion hole 98 of a connector mounting portion 96 (described later) and is disposed in the connector mounting portion 96. The connection tabs 70 are aligned in a busbar accommodating portion 44 provided in a portion of the upper surface of the base plate portion 32 that is approximately central in the X direction and on the near side in the Y direction, and protrude upward from the upper surface of the base plate portion 32. The other ends of the bus bars 16i to 16k are connected to the tab terminals 30 of the corresponding positive main contactor 22, negative main contactor 24, and pre-charge contactor 26 via the relay terminals 14, respectively.

[0027] <Upper-Side Component Mounting Portion (Current Sensor Mounting Portion 59, Outer Conductor Fastening Portions 72a-72d, and Electrical Component Fastening Portion 74)> In addition to the aforementioned current sensor mounting portion 59, the case body 12 is further provided with the outer conductor fastening portions 72a-72d and the electrical component fastening portion 74 as upper-side component mounting portions. External current-carrying members (not shown) are fastened to the outer conductor fastening portions 72a-72d with bolts and attached in a connected state to the bus bars 16a-16c. The fastening terminals 66a, 66b of the fuse 18 are fastened to the bolt fastening portion 62a of the bus bar 16f and the bolt fastening portion 62b of the bus bar 16g with fastening bolts 68 and attached in a connected state to the bus bars 16f, 16g.

[0028] The outer conductor fastening portions 72a-72d are provided on the protruding end of the support leg 34b. Four nut accommodating portions 76 are provided on the protruding end of the support leg 34b, opening upward and facing the bottom surface of the busbar accommodating portion 42b. Each nut accommodating portion 76 accommodates a nut 78 (see FIGS. 5 and 7). The external connection portions 52a-52d provided on the busbars 16a, 16c, 16d, and 16g are respectively arranged above the nut accommodating portions 76 and held by the busbar accommodating portion 42b. The outer conductor fastening portions 72a-72d are configured by including the nut accommodating portions 76, nuts 78, external connection portions 52a-52d, and busbar accommodating portion 42b arranged in this manner.

[0029] 1 and 4, even when the case body 12 is covered with the upper cover 31, the outer conductor fastening portions 72a to 72d are exposed to the outside through opening windows 80 provided in the upper cover 31 and open above the case body 12. In this manner, the outer conductor fastening portions 72a to 72d have a structure that allows external current-carrying members (such as wire harnesses and bus bars) (not shown) to be fastened from above the case body 12 and the upper cover 31 to the external connection portions 52a to 52d provided on the bus bars 16a, 16c, 16d, and 16g.

[0030] The electric component fastening portion 74 is provided at the protruding end of the support leg 34c. A pair of nut accommodating portions 82 are provided at the protruding end of the support leg 34c, opening upward and facing the bottom surface of the busbar accommodating portion 42c. Each nut accommodating portion 82 accommodates a nut 84 (see FIG. 7). The bolt fastening portions 62a, 62b provided on the busbars 16f, 16g are respectively disposed above the nut accommodating portions 82 and held by the busbar accommodating portion 42c. The fastening terminals 66a, 66b of the fuse 18 are placed on the bolt fastening portions 62a, 62b, thereby holding the fuse 18. The electric component fastening portion 74 is configured including the nut accommodating portions 82, nuts 84, bolt fastening portions 62a, 62b, and busbar accommodating portion 42c arranged in this manner.

[0031] 1 and 4 , even when the case body 12 is covered with the upper cover 31, the electric component fastening portion 74 is exposed to the outside through a through hole 86 provided in the upper cover 31 and opens above the case body 12. In this manner, the electric component fastening portion 74 has a structure that allows the fastening terminals 66a, 66b of the fuse 18 to be overlapped with the bolt fastening portions 62a, 62b provided on the bus bars 16f, 16g from above the case body 12 and the upper cover 31 and fastened with the fastening bolts 68.

[0032] <Upper Cover 31> The upper cover 31 has a shape that covers substantially the entire upper surface of the base plate portion 32 of the case body 12 and is made of an insulating material such as synthetic resin. Covering the upper surface of the case body 12 with the upper cover 31 prevents unexpected detachment of components from the case body 12 and ensures insulation. As shown in FIGS. 1, 4, and 7, a positive-side cover portion 88 is provided on the left end of the upper cover 31. The positive-side cover portion 88 is connected to the positive-side main contactor 22, the pre-charge contactor 26, and the pre-charge resistor 28 to form a positive-side circuit 89a and covers the bus bars 16a, 16b, and 16c held by the support leg portion 34a. A negative-side cover portion 90 is provided on the right end of the upper cover 31. The negative-side cover portion 90 is connected to the negative-side main contactor 24, the fuse 18, and the current sensor 20 to form a negative-side circuit 89b, and covers the bus bars 16d to 16g held by the support legs 34c. The negative-side cover portion 90 of the upper cover is provided with a through-hole 86 that exposes the electrical component fastening portion 74 to which the fuse 18 is fastened, and a through-hole 91 that exposes the current sensor mounting portion 59 to the outside. This makes it possible, with the case body 12 covered with the upper cover 31, to mount the fuse 18 to the electrical component fastening portion 74 from above and outside the electrical junction box 10, and then connect these to the negative-side circuit 89b by bolting.

[0033] A central cover portion 92 is provided between the positive electrode side cover portion 88 and the negative electrode side cover portion 90 in the left-right direction of the upper cover 31. The central cover portion 92 is disposed opposite the support leg 34b, and four opening windows 80 are provided penetrating the central cover portion 92 in areas corresponding to the external conductor fastening portions 72a to 72d housed in the busbar housing portion 42b of the support leg 34b. As a result, in the central cover portion 92, which is the center portion in the left-right direction of the upper cover 31, the external conductor fastening portions 72a to 72d are inserted through the opening windows 80 and exposed to the outside. As a result, with the case body 12 covered with the upper cover 31, it is possible to bolt external current-carrying members such as wire harnesses (not shown) to the external conductor fastening portions 72a to 72d from above and outside the electrical junction box 10 and connect them to the positive electrode side circuit 89a and the negative electrode side circuit 89b. In the first embodiment, a positive-side circuit 89a is provided on one end of the case body 12, while a negative-side circuit 89b is provided on the other end, and outer conductor fastening portions 72a to 72d are provided in the central portion of the case body 12. This allows the routing length of the bus bars 16a to 16k to be shorter than when the outer conductor fastening portions 72a to 72d are provided on the peripheral edge portion of the case body 12.

[0034] As shown in FIGS. 1 and 7 , a connection tab cover portion 94 that covers the upper and surrounding portions of the connection tabs 70 of the bus bars 16i to 16k is provided on the peripheral wall of the negative electrode cover portion 90 of the upper cover 31 on the front-rear direction (Y direction) and protrudes outward. The connection tab cover portion 94 is provided on the upper wall with a connector mounting portion 96 that protrudes upward and opens into a rectangular tube shape. As shown enlarged in FIG. 8 , the bottom wall of the connector mounting portion 96 is provided with four tab insertion holes 98 that penetrate in the vertical direction. The tip ends of the connection tabs 70 are inserted through the tab insertion holes 98 and positioned within the connector mounting portion 96. A pair of guide tube portions 100 that protrude downward are provided on the bottom wall of the connector mounting portion 96 around the tab insertion holes 98. On the upper surface of the base plate portion 32 facing the upper wall of the connection tab cover portion 94 in the Z direction, an area including the recessed bus bar accommodating portion 44 forms a connection tab mounting portion 102, on which the connection tabs 70 held in the bus bar accommodating portion 44 are mounted in an aligned state. A pair of positioning protrusions 104 protrude upward from the periphery of the connection tab mounting portion 102 at locations facing the pair of guide tube portions 100. When assembling the upper cover 31 to the case body 12, the positioning protrusions 104 are inserted into the guide tube portions 100 before the connection tabs 70 are inserted into the tab insertion holes 98, thereby positioning the connection tabs 70 in the tab insertion holes 98. This facilitates the assembly of the upper cover 31 to the case body 12 while reducing the risk of deformation of the connection tabs 70. An external connector connected to an external control circuit (not shown) is attached to the connector mounting portion 96.

[0035] <Assembly of Electrical Junction Box 10> A specific example of a method for assembling the electrical junction box 10 will now be described. However, the method for assembling the electrical junction box 10 is not limited to the embodiment described below.

[0036] First, the relay terminals 14 are inserted from above the case body 12 through the upper openings 46 into the relay terminal accommodating portions 45 provided in appropriate positions on the case body 12. Furthermore, nuts 78, 84 are accommodated in the nut accommodating portions 76, 82 provided in appropriate positions on the case body. Next, the multiple bus bars 16a to 16k are arranged in predetermined locations from above the case body 12 and accommodated and held in the bus bar accommodating portions 42a to 42c, 44 provided in appropriate positions on the case body 12. Then, the upper cover 31 that covers the top surface of the case body 12 is assembled from above the case body 12 to the case body 12 to which the bus bars 16a to 16k have been assembled in this manner.

[0037] Next, the case body 12 is turned upside down so that the upper cover 31 faces downward. In this state, the positive main contactor 22, the negative main contactor 24, the pre-charge contactor 26, and the pre-charge resistor 28 are sequentially mounted in the lower component mounting portions 36a to 36d. As shown in FIG. 2 , each of the lower component mounting portions 36a to 36d is provided with an elastically deformable locking portion 106. For example, by fitting each locking portion 106 to a locking protrusion (not shown) protruding from the housing of the positive main contactor 22, the negative main contactor 24, or the pre-charge contactor 26 or to the housing of the pre-charge resistor 28, the lower component can be prevented from falling or coming off the lower component mounting portions 36a to 36d.

[0038] Thereafter, the case body 12 is turned upside down so that the upper cover 31 is on top. In this state, the fuse 18 is attached from above to the electrical component fastening portion 74 exposed to the outside through the through hole 86 of the upper cover 31 and fastened with a bolt. Also, the current sensor 20 is attached from above to the current sensor mounting portion 59 exposed to the outside through the through hole 91 of the upper cover 31 and fastened with a bolt. This completes the electrical junction box 10 of the first embodiment.

[0039] The electrical junction box 10 of the first embodiment configured as described above includes upper component mounting portions that open upward in the case body 12, such as the external conductor fastening portions 72a-72d, the electrical component fastening portion 74, and the current sensor mounting portion 59, as well as lower component mounting portions 36a-36d that open downward in the case body. Furthermore, the external conductor fastening portions 72a-72d and the lower component mounting portion 36a, to which the positive main contactor 22 is attached, are arranged to completely overlap in the vertical direction (Z direction) of the case body 12. The lower component mounting portion 36b, to which the electrical component fastening portion 74 and the negative main contactor 24 are attached, are also arranged to completely overlap in the vertical direction (Z direction) of the case body 12. This eliminates the need to space the upper component mounting portions and the lower component mounting portions apart in the X and Y directions, which are perpendicular to the vertical direction (Z direction) of the case body 12, thereby enabling the case body 12 to be made smaller in the X and Y directions.

[0040] The lower component mounting sections 36a to 36d are respectively fitted with the positive main contactor 22, the negative main contactor 24, the pre-charge contactor 26, and the pre-charge resistor 28, which are lower components having tab terminals 30. These tab terminals 30 are inserted through lower openings 48 of the relay terminal accommodating section 45 and connected to the relay terminals 14, thereby electrically connecting the lower components to the bus bars 16a to 16k. By using the relay terminals 14 accommodated in such relay terminal accommodating section 45, it is possible to electrically connect the lower components to the bus bars 16a to 16k accommodated in the case body 12, without having to assemble the lower components from above the case body. This allows the lower components to be assembled to the lower component mounting portions 36a to 36b, while the lower component mounting portions 36a to 36b can be made to overlap in the vertical direction with the outer conductor fastening portions 72a to 72d and the electrical component fastening portion 74, making it possible to reduce the size of the case body 12 and the electrical junction box 10 itself in the X and Y directions without compromising assembly workability.

[0041] In addition, in the vertical direction of the case body 12, the connection between the upper component mounting portions (particularly the outer conductor fastening portions 72a to 72d and the electrical component fastening portion 74) and the lower component mounting portions 36a, 36b is realized using the relay terminals 14 arranged between them, which advantageously reduces the routing length of the bus bars 16a to 16k.

[0042] In addition, the upper component mounting sections include external conductor fastening sections 72a to 72d, electrical component fastening section 74, and current sensor mounting section 59, all of which require bolt fastening work, so assembly work can be easily performed from above the case main body 12.

[0043] As shown in Figures 5 and 6, the lower component mounting portions 36c, 36d are arranged to overlap in the up-down direction of the case body 12. Specifically, the lower component mounting portion 36c is located above the lower component mounting portion 36d in the up-down direction of the case body 12. As is clear from Figure 6, both ends of the lower component mounting portion 36d in the Y direction protrude beyond both ends of the lower component mounting portion 36c in the Y direction. The tab terminal 30 of the pre-charge resistor 28 mounted on the lower component mounting portion 36d is located at a position that does not overlap the lower component mounting portion 36c in the up-down direction. Therefore, the relay terminal 14 to which the tab terminal 30 of the pre-charge resistor 28 is connected can be located outward in the Y direction from both ends of the lower component mounting portion 36c, allowing the lower component mounting portions 36c, 36d, to be arranged to overlap in the up-down direction of the case body 12. In this way, by overlapping the multiple lower component mounting sections 36c, 36d in the vertical direction of the case body 12, the case body 12 and the electrical junction box 10 can be made even more compact in the X and Y directions.

[0044] <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.

[0045] (1) In the above embodiment, the upper component mounting portion (the outer conductor fastening portions 72a to 72d and the electrical component fastening portion 74) and the lower component mounting portions 36a, 36b are arranged to completely overlap in the vertical direction (Z direction) of the case body 12. However, they may be arranged to partially overlap, and even in such a case, the case body 12 and the electrical junction box 10 can be made smaller in the X and Y directions.

[0046] (2) In the above embodiment, a structure in which the upper component mounting portion is bolted to the bus bar is exemplified. However, this is not limited to this, and any structure, such as a relay terminal or a solder connection, can be used as the structure connected to the bus bar.

[0047] (3) In the above embodiment, the two lower component mounting portions 36c, 36d are arranged to overlap in the vertical direction of the case body 12. However, three or more lower component mounting portions may be arranged to overlap in the vertical direction. Furthermore, it is not necessary to have multiple lower component mounting portions overlap in the vertical direction. The electrical junction box 10 may be made smaller in the X and Y directions by increasing the number of upper component mounting portions that overlap in the vertical direction with lower component mounting portions.

[0048] REFERENCE SIGNS LIST 10 Electrical junction box 12 Case body 14 Relay terminal 16a to 16k Bus bar 18 Fuse (upper side component) 20 Current sensor (upper side component) 22 Positive main contactor (lower side component) 24 Negative main contactor (lower side component) 26 Pre-charge contactor (lower side component) 28 Pre-charge resistor (lower side component) 30 Tab terminal 31 Upper cover 32 Base plate portion 34a to 34c Support leg portion 36a to 36d Lower side component mounting portion 38 Fastening bolt 40 Bolt fixing portion 42a to 42c Bus bar accommodating portion 44 Bus bar accommodating portion 45 Relay terminal accommodating portion 46 Upper opening 48 Lower opening 50a to 50h Connection portion (part of bus bar) 52a to 52d External connection portion 56 Input terminal 57 Bolt 58 Output terminal 59 Current sensor mounting portion 60 One end portion 61 Nut 62a, 62b Bolt fastening portion 66a, 66b Fastening terminal portion 68 Fastening bolt 70 Connection tab 72a to 72d Outer conductor fastening portion (upper side component mounting portion) 74 Electrical component fastening portion (upper side component mounting portion) 76 Nut accommodating portion 78 Nut 80 Opening window 82 Nut accommodating portion 84 Nut 86 Through hole 88 Positive electrode side cover portion 90 Negative electrode side cover portion 91 Through hole 92 Central cover portion 94 Connection tab cover portion 96 Connector mounting portion 98 Tab insertion hole 100 Guide tube portion 102 Connection tab mounting portion 104 Positioning protrusion 106 Locking portion

Claims

an upper component mounting portion that opens at the top of the case body and is adapted to mount upper components that are assembled from above and connected to the busbars; and a lower component mounting portion that opens at the bottom of the case body and is adapted to mount lower components that are assembled from below and connected to the busbars, wherein the upper component mounting portion and the lower component mounting portion are arranged to overlap in the vertical direction of the case body, a portion of the busbars is connected to the relay terminals, and the lower components have tab terminals that are inserted through the lower openings of the relay terminal accommodating portion and are connected to the relay terminals by being inserted through the lower openings of the relay terminal accommodating portion, thereby electrically connecting the lower components to the busbars.

2. An electrical connection box as described in claim 1, wherein the upper component mounting portion includes an external conductor fastening portion that holds an external connection portion provided on the bus bar and allows an external current-carrying member to be fastened to the external connection portion from above.

3. An electrical connection box as described in claim 2, wherein a positive circuit is provided at one end side of the case body, a negative circuit is provided at the other end side of the case body, and the external conductor fastening portion is provided in the central portion of the case body.

4. An electrical connection box as described in claim 1 or claim 2, wherein the upper component mounting portion includes an electrical component fastening portion that holds an electrical component including a fastening terminal portion that is bolted to a bolt fastening portion provided on the bus bar and allows the fastening terminal portion to be bolted to the bolt fastening portion from above.

5. An electric junction box according to claim 1 or 2, wherein said lower component mounting portion includes a plurality of said lower component mounting portions arranged so as to overlap each other in the vertical direction.

6. An electrical connection box as described in claim 1 or claim 2, wherein the lower component mounting portion has a locking portion that engages with the lower component to hold the lower component in a connected state to the bus bar and prevent the lower component from falling off the lower component mounting portion.

7. An electrical junction box as claimed in claim 1 or 2, further comprising an upper cover covering an upper surface of said case body, said upper cover having a connector mounting portion opening upward, a tab insertion hole formed through a bottom wall of said connector mounting portion, and a guide tube portion protruding downwardly around said connector mounting portion, said bus bar having a connection tab inserted through said tab insertion hole of said connector mounting portion and positioned on said connector mounting portion, said case body having a connection tab mounting portion formed on said upper surface and positioning protrusions protruding upwardly around said connection tab mounting portion, and when said upper cover is assembled to said case body, before said connection tab is inserted through said tab insertion hole, said positioning protrusions are inserted into said guide tube portion so that said connection tab is positioned in said tab insertion hole.

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