Electrical junction box

Abstract

This utility model relates to a junction box disposed in a battery pack having battery cells. It includes: a frame; and a fuse housed within the frame and electrically connected to the battery cells. The fuse is inclined such that one end in a predetermined direction is positioned higher than the other end in the same predetermined direction. Using this utility model, short circuits in the battery pack can be suppressed even when a load is input to the junction box containing the fuse.

Description

Technical Field

[0001] This utility model relates to an electrical junction box. Background Technology

[0002] Japanese Patent Application Publication No. 2019-40808 discloses a battery pack having a battery casing housing a battery cell and an upper casing covering the battery cell and a fuse from above. The fuse disclosed in Japanese Patent Application Publication No. 2019-40808, which prevents short circuits in the battery pack, comprises: a fuse body; a casing made of insulating resin housing and retaining the fuse body; a cover made of insulating resin covering the casing; and a pair of second terminals protruding in opposite directions at both ends.

[0003] In the aforementioned battery pack, the fuse (hereinafter referred to as the "fuse") is covered by the upper casing. Therefore, when a load is applied to the battery pack, the load is transferred to the upper casing before being transferred to the fuse. If a load is applied to the upper casing, a portion of the upper casing is pressed and collides directly or indirectly with the fuse. At this time, the compressive load is applied to the fuse colliding with the upper casing, and the fuse may be crushed. If the fuse is crushed, its function (specifically, its function of preventing short circuits in the battery pack) is lost, potentially leading to a short circuit in the battery pack. Utility Model Content

[0004] In view of the above facts, the purpose of this utility model is to obtain a junction box that can suppress short circuits of the battery pack even when a load is input to the junction box with a fuse inside.

[0005] The first technical solution's junction box is a junction box installed in a battery pack having battery cells, comprising: a frame; and a fuse housed in the frame and electrically connected to the battery cells, wherein the fuse is inclined such that one end of a predetermined direction is higher than the other end of the predetermined direction.

[0006] According to the junction box described in the first technical solution, a fuse is inclined such that one end in a predetermined direction is positioned higher than the other end in the same predetermined direction. For example, if a load is input to the junction box from one side in the predetermined direction, a portion of the frame is pressed and collides directly or indirectly with the fuse housed inside the frame. At this time, the fuse pressed against the frame rotates by lifting the end on one side in the predetermined direction (i.e., the upper end). Thus, the compressive load input to the fuse is reduced by the rotation of the fuse. As a result, the fuse is less likely to be crushed. Therefore, it is possible to prevent large-scale fuse damage (such as damage accompanied by large deformation such as crushing) that renders the fuse unable to function (specifically, the function of preventing short circuits in the battery pack) from occurring. Therefore, even when a load is input to the junction box, the function of the fuse can be easily maintained, thereby suppressing short circuits in the battery pack.

[0007] The second technical solution describes a junction box that is the same as the junction box described in the first technical solution. The junction box has a busbar that protrudes from the end of the fuse in the specified direction and electrically connects the battery unit to the fuse. The busbar is inclined such that the end on one side of the specified direction is higher than the end on the other side of the specified direction.

[0008] According to the junction box described in the second technical solution, the busbar is inclined such that one end in a predetermined direction is positioned higher than the other end in the same predetermined direction. Therefore, for example, when a load is input to the junction box from one side in the predetermined direction, the busbar also rotates by lifting the end in that direction (i.e., the upper end). This rotation of the busbar prevents it from moving in the predetermined direction and inserting into the fuse. Consequently, large-scale fuse damage (such as the busbar inserting into the fuse) that prevents the fuse from functioning properly (specifically, preventing short circuits in the battery pack) is less likely to occur. Therefore, fuse function can be easily maintained, and short circuits in the battery pack can be suppressed more effectively.

[0009] The third technical solution is a junction box as described in the first or second technical solution, wherein the fuse is disposed at one end of the battery pack on one side of the specified direction.

[0010] According to the third technical solution, a fuse is provided at one end of the junction box on one side of the battery pack in a specified direction. Therefore, when a load is input from one side of the battery pack in the specified direction, even if a large load is applied to the junction box, as described above, the fuse is difficult to break by rotating it. Thus, even under a large load, large-scale fuse damage (such as damage from large deformation accompanied by crushing) can be suppressed, and the fuse's function is easily maintained, thereby more effectively suppressing short circuits in the battery pack.

[0011] As described above, the junction box of this utility model has the excellent effect of suppressing short circuits in the battery pack even when a load is input. Attached Figure Description

[0012] Figure 1 A top view showing the floor panel and battery pack involved in the embodiment of this utility model.

[0013] Figure 2 for Figure 1 The image shows an exploded perspective view of the battery pack.

[0014] Figure 3 for Figure 2 The exploded perspective view of the electrical junction box is shown.

[0015] Figure 4 for Figure 2 A schematic cross-sectional view of the AA line. Detailed Implementation

[0016] The following is for reference Figures 1-4 The embodiment of the junction box 50 of this utility model will be described. In addition, in the figures, arrow FR appropriately indicates the front of the vehicle in the front-rear direction, arrow OUT indicates the outer side in the vehicle width direction, arrow UP indicates the upper side of the vehicle in the vehicle vertical direction, and arrow RH indicates the right side in the vehicle width direction (left-right direction). In the following description, when referred to only as "front-rear direction," "width direction," and "vertical direction," these refer to the vehicle front-rear direction, vehicle width direction, and vehicle vertical direction, respectively. Furthermore, "left-right direction" refers to the left-right direction when facing forward of the vehicle.

[0017] Vehicles using the junction box 50 of this embodiment are, for example, hybrid vehicles (HV). However, vehicles that can use the junction box 50 of this embodiment are not limited to HVs. For example, the junction box 50 of this embodiment can also be applied to battery electric vehicles (BEV) or plug-in hybrid electric vehicles (PHEV).

[0018] First, use Figure 1 and Figure 2 The battery pack 20, which is equipped with a power junction box 50, will be described. Additionally, in... Figure 1 The battery cover 34 and electrical component cover 46 of the battery pack 20, which will be described later, are omitted from the illustration.

[0019] like Figure 1 As shown, the battery pack 20 is disposed on the upper surface of the floor panel 10. The battery pack 20 is positioned slightly forward of the center of the floor panel 10 in the vehicle's longitudinal direction. Furthermore, the battery pack 20 is disposed at the center of the floor panel 10 in the vehicle's width direction. The battery pack 20 is arranged with its length along the vehicle's width direction. A cooling fan 21 for cooling the battery pack 20 is connected to the left side of the battery pack 20.

[0020] like Figure 1 and Figure 2 As shown, the battery pack 20 includes: a battery section 30 that houses a battery module 35 having multiple battery cells (not shown); and an electrical component section 40 that houses electrical components such as a junction box 50 connected to the battery module 35. The battery section 30 and the electrical component section 40 are arranged side by side in the vehicle width direction. The electrical component section 40 is fixed to the right end of the battery section 30.

[0021] like Figure 1 As shown, the battery unit 30 includes a battery housing 31 with an internal space and a plurality of battery modules 35 housed inside the battery housing 31.

[0022] The battery housing 31 has: a bottom portion 32 below the defined interior space; a side portion 33 erected from the end of the bottom portion 32 in the vehicle width direction and the vehicle front-rear direction; and a battery cover 34 covering the interior space from the top (see reference). Figure 2 ).

[0023] A battery module 35 is mounted on the upper surface of the bottom section 32. Additionally, the lower ends of side sections 33 are connected to the ends of the bottom section 32 in the vehicle's longitudinal direction and on both sides in the vehicle's width direction. The side sections 33 define the longitudinal and lateral directions of the interior space. The lower ends of the side sections 33 are connected to the upper surface of the bottom section 32. Figure 2 As shown, the battery cover 34 is mounted on the side portion 33. The battery cover 34 is curved such that its central portion in the rear-rear direction becomes the apex.

[0024] like Figure 1 As shown, multiple battery modules 35 are mounted on the bottom surface 32 of the battery housing 31. Each battery module 35 has multiple battery cells (not shown) stacked in a predetermined direction. In this embodiment, as an example, the multiple battery cells are stacked in the vehicle width direction. Furthermore, in this embodiment, the battery cells, for example, store electricity for driving an electric generator (not shown), and supply electricity to the electric generator (not shown) via a power control unit (not shown). As battery cells, for example, secondary batteries such as nickel-metal hydride batteries or lithium-ion batteries are used. The multiple battery modules 35 are arranged in two rows side-by-side along the vehicle width direction.

[0025] like Figure 2 As shown, the electrical component section 40 includes: an electrical component housing 41 with an internal space, electrical components (not shown) housed inside the electrical component housing 41, and a junction box 50. The electrical component section 40 is located at the right end of the battery pack 20.

[0026] The electrical component housing 41 has: a bottom 42 below the defined interior space; a front cover 43 erected from the front end of the bottom 42 in the vehicle longitudinal direction; a rear cover 44 erected from the rear end of the bottom 42 in the vehicle longitudinal direction; a side cover 45 erected from the outer end of the bottom 42 in the vehicle width direction; and an electrical component cover 46 covering the interior space from the top.

[0027] A junction box 50, etc., is mounted on the upper surface of the bottom 42. Furthermore, the lower ends of a front cover 43, a rear cover 44, and a side cover 45 are respectively connected to the ends of the bottom 42 in the vehicle's longitudinal direction and in the vehicle's width direction. The front cover 43 defines the front of the interior space. The rear cover 44 defines the rear of the interior space. The side cover 45 defines the outer direction in the vehicle's width direction. An electrical component cover 46 is mounted on the side portion 33.

[0028] The electrical component housing 41 houses a junction box 50, which is electrically connected to the battery module 35, and other electrical components. Examples of these electrical components include connectors for connecting wiring harnesses, which connect the battery ECU (Electronic Control Unit) (not shown) that manages the battery module 35, to the junction box 50.

[0029] In addition, the components around the junction box 50 (such as the electrical component housing 41) are parts made of sheet metal (in other words, sheet metal parts).

[0030] like Figure 3 and Figure 4 As shown, the junction box 50 includes a frame 51, a fuse 52 and a busbar 53 housed in the frame 51, a first relay 54, a second relay 55, and a current sensor 56 mounted on the frame 51. The junction box 50 supplies and cuts off power to the battery module 35, or distributes power from the battery module 35 to the electric drive unit (not shown), etc., through the first relay 54 and the second relay 55.

[0031] The frame 51 has a cover 57 for mounting the first relay 54, etc., and a housing 58 mounted on the lower part of the cover 57.

[0032] Cover 57 covers housing 58 from above. Cover 57 is a box-shaped component with an opening at the lower end. Housing 58 is inserted into the opening at the lower end of cover 57. Cover 57 is provided with a first relay mounting part 64, a second relay mounting part 65, and a current sensor mounting part 66, which will be described later.

[0033] The housing 58 has a flat bottom wall portion 58A and a side wall portion 58B extending from the outer periphery of the bottom wall portion 58A. The housing 58 is fitted into the cover 57 such that the outer surface of the side wall portion 58B contacts the inner surface of the cover 57.

[0034] A fuse housing 62 is provided at the front of the frame 51 to house the fuse 52 and the busbar 53. The fuse housing 62 has a housing chamber 62A that houses the fuse 52 and the busbar 53 inside, and a fuse cover 62B that covers the housing chamber 62A from above.

[0035] The containment chamber 62A is located at the front of the electrical junction box 50. For example... Figure 4 As shown, the sides of the containment chamber 62A are defined by the frame 51. Furthermore, the lower part of the containment chamber 62A is defined by the bottom wall portion 58A of the housing 58. Additionally, the upper part of the containment chamber 62A is defined by the fuse cover 62B.

[0036] On the frame 51 (more specifically, the cover 57), a first relay mounting portion 64 is provided on the rear side of the fuse housing portion 62. The first relay mounting portion 64 has a pair of first wall portions 64A that are separated from each other and opposite each other in the vehicle width direction. The two ends of each first wall portion 64A in the vehicle front-rear direction are bent toward the other first wall portion 64A. In addition, a cutout is provided at the upper end of each first wall portion 64A in a downward recessed manner. The first relay 54 is provided inside the first relay mounting portion 64 (in other words, in the space between the pair of first wall portions 64A).

[0037] Furthermore, a second relay mounting portion 65 is provided on the frame 51 (specifically, cover 57) on the rear side of the first relay mounting portion 64. The second relay mounting portion 65 has a pair of second wall portions 65A that are separated from each other and opposite each other in the vehicle width direction. The two ends of each second wall portion 65A in the vehicle longitudinal direction are bent towards the other second wall portion 65A. Additionally, a cutout is provided at the upper end of each second wall portion 65A in a downward recessed manner. The second relay 55 is provided inside the second relay mounting portion 65 (in other words, in the space between the pair of second wall portions 65A).

[0038] Additionally, a current sensor mounting section 66 is provided on the frame 51 (more specifically, the cover 57) on the rear side of the second relay mounting section 65. The current sensor mounting section 66 is a rectangular cylindrical component with an opening at its upper end. A current sensor 56 is mounted on the current sensor mounting section 66.

[0039] Fuse 52 is electrically connected to the battery cell. Fuse 52 prevents a short circuit in the battery pack 20 by cutting off the circuit provided in the battery pack 20. Fuse 52 has a cylindrical fuse body 52A and a pair of end caps 52B covering both ends of the fuse body 52A. Fuse 52 is configured to extend along the width direction of the vehicle.

[0040] The fuse body 52A is a cylindrical component with its central axis extending along the width of the vehicle. The fuse body 52A is made of, for example, glass or ceramic. A fusing element (not shown) is disposed inside the fuse body 52A. The fuse 52 breaks the circuit by melting the fusing element when an excessive current flows through it, preventing a short circuit in the battery pack 20. End caps 52B are fixed to both ends of the fuse body 52A in the vehicle width direction.

[0041] Each end cap 52B is made of conductive metal. Each end cap 52B is a cylindrical shape with a bottom. A busbar 53 is fixed on each end cap 52B.

[0042] The busbar 53 protrudes from each end cap 52B in the vehicle width direction. That is, the busbar 53 extends outward from the end cap 52B covering the outer side of the fuse body 52A in the vehicle width direction. On the other hand, the busbar 53 extends inward from the end cap 52B covering the inner side of the fuse body 52A in the vehicle width direction.

[0043] Each busbar 53 is a plate-shaped metal component, arranged vertically along its thickness. Furthermore, each busbar 53 has a circular through-hole 53A. Each busbar 53 is connected by a bolt 62C inserted into the through-hole 53A (see reference). Figure 3 It is fixed to frame 51. Additionally, in Figure 4 For the sake of illustration, bolt 62C is omitted in the illustration.

[0044] like Figure 4 As shown, the fuse 52 and a pair of busbars 53 are housed inside the fuse housing 62. The fuse 52 and the pair of busbars 53 are arranged in a manner that extends along the vehicle width direction in the length direction. In addition, the fuse 52 is inclined such that its outer end (on one side) in the vehicle width direction (prescribed direction) is positioned higher than its inner end (on the other side) in the vehicle width direction. In other words, the fuse 52 is inclined downwards as it moves from the outer side towards the inner side in the vehicle width direction.

[0045] The orientation of fuse 52 is described in detail. Fuse 52 is inclined such that the lower end of its outer end in the vehicle width direction is higher than the lower end of its inner end in the vehicle width direction. In addition, fuse 52 is inclined such that the upper end of its outer end in the vehicle width direction is higher than the upper end of its inner end in the vehicle width direction.

[0046] In addition, each busbar 53 is also inclined in the same way as the fuse 52, with the outer end (one side) in the vehicle width direction (prescribed direction) being higher than the inner end (the other side) in the vehicle width direction.

[0047] The tilt angle of the fuse 52 is the same as the tilt angle of the busbar 53. Alternatively, the tilt angle of the fuse 52 may be, for example, the angle between the central axis of the fuse body 52A and the horizontal plane. Similarly, the tilt angle of the busbar 53 may be, for example, the angle between the surface of the plate-shaped busbar 53 and the horizontal plane.

[0048] The first relay 54 and the second relay 55 are respectively mounted in the first relay mounting part 64 and the second relay mounting part 65. The first relay 54 and the second relay 55 are configured to switch to an on state and an off state respectively according to the on / off signal output from the battery ECU. The current sensor 56 is mounted in the current sensor mounting part 66.

[0049] According to this embodiment, the following effects are achieved.

[0050] In this embodiment, the fuse 52 is inclined such that its outer side (one side) in the vehicle width direction is higher than its inner side (the other side) in the vehicle width direction. For example, if a load is input to the junction box 50 from the outer side in the vehicle width direction, a portion of the frame 51 is pressed and directly or indirectly collides with the fuse 52 housed inside the frame 51. At this time, the fuse 52 pressed by the frame 51 rotates by lifting its outer end (i.e., the upper end) in the vehicle width direction (see reference). Figure 4 (See arrow A1). Thus, by rotating the fuse 52, it becomes difficult for the fuse 52 to compress in the vehicle width direction, thereby reducing the compressive load input to the fuse 52. This makes it difficult for the fuse 52 to be crushed. Therefore, it is difficult for large-scale damage to the fuse 52 (such as damage accompanied by large deformation like crushing) to occur, preventing it from functioning properly (specifically, preventing short circuits in the battery pack 20). Therefore, even when a load is input to the junction box 50, the function of the fuse 52 can be easily maintained, thus suppressing short circuits in the battery pack 20.

[0051] In addition, as an example of a case where a load is input to the junction box 50 from the width direction of the vehicle, cases can be listed such as interference between the side of the vehicle and obstacles on the road, and cases where a crush test of the battery pack 20 is conducted.

[0052] Furthermore, in this embodiment, the busbar 53 is inclined such that its outer end in the vehicle width direction is positioned higher than its inner end in the vehicle width direction. Therefore, for example, when a load is input to the junction box 50 from the outer side in the vehicle width direction, the busbar 53 also rotates with its outer end (i.e., the upper end) lifted. This rotation of the busbar 53 prevents it from moving in the vehicle width direction and inserting into the fuse 52. Consequently, large-scale damage to the fuse 52 (such as damage caused by the busbar 53 inserting into the fuse 52) is less likely to occur, preventing it from functioning properly. Therefore, the function of the fuse 52 can be easily maintained, thus more effectively suppressing short circuits in the battery pack 20.

[0053] Alternatively, the junction box 50 housing the fuse 52 can be reinforced to prevent damage to the fuse 52. However, this method may increase the number of parts in the junction box 50 due to the need for reinforcing materials. On the other hand, the junction box 50 in this embodiment can suppress damage to the fuse 52 even without reinforcing materials. Therefore, it is not necessary to reinforce the junction box 50 with reinforcing materials, thus reducing the number of parts in the junction box 50 compared to cases where reinforcing materials are used. Therefore, the manufacturing cost of the junction box 50 (and consequently the battery pack 20) ​​can be reduced. Furthermore, lightweighting and miniaturization can be achieved.

[0054] In this embodiment, the fuse 52 is located at the outer end of the battery pack 20 in the vehicle width direction. Therefore, when a load is input from the outer side of the battery pack 20 in the vehicle width direction, a large load is input to the junction box 50. However, in the junction box 50 according to this embodiment, as described above, the fuse 52 is difficult to crush by rotating it. Therefore, even under large loads, large-scale damage to the fuse 52 (e.g., damage accompanied by large deformation such as crushing) can be suppressed, and the function of the fuse 52 is easily maintained, thus more effectively suppressing short circuits in the battery pack 20.

[0055] The above description of the electrical junction box of the embodiment has been provided, but the present invention can be appropriately modified without departing from its spirit.

[0056] For example, in the above embodiment, an example was described where the tilt angle of the fuse 52 and the tilt angle of the busbar 53 are the same, but the present invention is not limited thereto. The tilt angle of the fuse 52 and the tilt angle of the busbar 53 may also be different angles.

Claims

1. A power connection box provided in a battery pack having a battery cell, characterized by, have: Frame; and The fuse, housed within the frame, is electrically connected to the battery cell. The fuse is inclined such that one end of a specified direction is higher than the other end of the specified direction.

2. The junction box of claim 1, wherein, The device includes a busbar that protrudes from the end of the fuse in the specified direction and electrically connects the battery cell to the fuse. The busbar is inclined such that one end of the specified direction is higher than the other end of the specified direction.

3. The electrical junction box according to claim 1 or 2, characterized in that, The fuse is located at one end of the battery pack on one side of the specified direction.

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