Manufacturing method of electric connection box

Abstract

To provide a manufacturing method of an electric connection box capable of making connection stiffness between a relay and a bus bar compatible with a heat dissipation property and an insulation property.SOLUTION: A manufacturing method of a battery cut-off unit 1 that is an example of an electric connection box includes the steps of: disposing a relay 20 in a case 10 to which a bus bar 30 is fixed; disposing a relay cover 40 on the relay 20 which is disposed in the case 10; fixing the relay cover 40 and the case 10 in a state where the relay cover 40 is pressed toward the case 10; and fixing a terminal 21 of the relay 20 and the bus bar 30 by a screw after the relay cover 40 and the case 10 are fixed.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present disclosure relates to an electrical junction box, such as a battery disconnect unit, and a method for manufacturing the electrical junction box. [Background technology]

[0002] 2. Description of the Related Art Electric vehicles, such as hybrid electric vehicles or pure electric vehicles, are equipped with a battery for power supply, and also with an electrical junction box for connecting the battery to various electrical devices (Patent Document 1).

[0003] A battery disconnect unit (BDU) is known as this type of electrical connection box. The battery disconnect unit includes a relay that cuts off and supplies power output from a battery. For example, the battery disconnect unit includes a resin case, a relay housed in the case, and a bus bar connected to the terminal of the relay. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2005-210804 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in conventional battery cutoff units, the connection strength between the terminals (fixed terminals) of the relay and the bus bars is not sufficient.

[0006] In addition, in the battery cutoff unit, heat is generated from the relay, which is a power device, but because the distance from the relay terminal to the external heat sink is long, it is difficult to sufficiently dissipate the heat generated by the relay. In particular, when an electric vehicle suddenly discharges current from the battery due to a short-term sudden acceleration, the relay becomes very hot.

[0007] Furthermore, in battery cutoff units, it is important to ensure insulation because a large current flows through the bus bars, but depending on the insulation structure, this can become an obstacle to dissipating the heat generated by the relay.

[0008] As described above, conventional battery cutoff units have a problem in that it is difficult to achieve a strong connection between the relay and the bus bar while also providing heat dissipation and insulation.

[0009] The present disclosure has been made to solve such problems, and aims to provide an electrical junction box and a method for manufacturing an electrical junction box that can achieve both strong connection between a relay and a bus bar, heat dissipation properties, and insulation properties. [Means for solving the problem]

[0010] In order to achieve the above object, one aspect of an electrical connection box according to the present disclosure comprises an insulating resin case, a relay disposed in the case, a bus bar connected to a terminal of the relay and fixed to the case by insert molding, a metal plate, and a thermally conductive sheet disposed between the case and the metal plate.

[0011] Furthermore, one aspect of a manufacturing method for an electrical junction box according to the present disclosure includes the steps of placing a relay in a case to which a bus bar is fixed, placing a relay cover on the relay placed in the case, fixing the relay cover and the case while pressing the relay cover against the case, and, after fixing the relay cover and the case, fixing the terminals of the relay and the bus bar with screws. Effect of the Invention

[0012] According to the present disclosure, it is possible to achieve both strong connection between the relay and the bus bar, heat dissipation properties, and insulation properties. [Brief description of the drawings]

[0013] [Figure 1] FIG. 2 is a block diagram of a drive system according to an embodiment. [Diagram 2] FIG. 2 is a perspective view of a battery cutoff unit according to an embodiment. [Diagram 3] FIG. 2 is an exploded perspective view of the battery cutoff unit according to the embodiment. [Figure 4] 2 is a cross-sectional view of a battery cutoff unit according to an embodiment of the present invention; [Diagram 5] 2 is an enlarged cross-sectional view showing a main part of the battery cutoff unit according to the embodiment; FIG. [Figure 6] 11A to 11C are diagrams for explaining a manufacturing method of a battery cut-off unit according to an embodiment. [Figure 7] 11A and 11B are diagrams illustrating a configuration of a battery cutoff unit of a comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, the embodiments of the present disclosure will be described with reference to the drawings. Note that each of the embodiments described below shows a specific example of the present disclosure. Therefore, the numerical values, components, the arrangement and connection of the components, the steps, and the order of the steps shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Therefore, among the components in the following embodiments, components that are not described in the independent claims will be described as optional components.

[0015] Note that each figure is a schematic diagram and is not necessarily a precise illustration. In addition, in each figure, substantially the same configuration is given the same reference numeral, and duplicated explanations are omitted or simplified. In addition, in this specification, the terms "upper" and "lower" do not necessarily refer to the upper direction (vertically upward) and the lower direction (vertically downward) in absolute spatial recognition.

[0016] (Embodiment) First, a drive system 100 will be described as an example of a system that uses a battery cutoff unit 1 according to an embodiment. Fig. 1 is a block diagram of the drive system 100 according to an embodiment.

[0017] As shown in FIG. 1, the drive system 100 includes a battery cutoff unit 1, a battery 2, and an inverter 3.

[0018] The battery cutoff unit 1 is an example of an electric connection box for connecting the battery 2 and various electric devices. For example, the battery cutoff unit 1 is connected between the battery 2 and the inverter 3, and cuts off or supplies DC power output from the battery 2 to the inverter 3. In other words, the battery cutoff unit 1 can switch between a power supply state in which power is supplied to the inverter 3 and a power cutoff state in which power to the inverter 3 is cut off.

[0019] Although not shown, the battery cutoff unit 1 may be connected not only to the inverter 3 but also to a rapid charging circuit. In this case, the battery cutoff unit 1 can switch the output destination of the DC power output from the battery 2 to the inverter 3 or the rapid charging circuit. The battery cutoff unit 1 can also switch between a power supply state in which power is supplied to the rapid charging circuit and a power cutoff state in which power to the rapid charging circuit is cut off. As another embodiment, the battery cutoff unit 1 can also be equipped with a rapid charging circuit.

[0020] The battery 2 is an electricity storage device such as a secondary battery. DC power is output from the battery 2. Therefore, the battery 2 connected to the battery cutoff unit 1 supplies DC power to the battery cutoff unit 1. The battery 2 is, for example, a lithium ion secondary battery, but is not limited thereto.

[0021] The inverter 3 is an AC / DC converter, and converts the DC power supplied from the battery cutoff unit 1 into AC power. Although not shown, the inverter 3 is connected to, for example, a motor, and the motor connected to the inverter 3 is driven by the AC power output from the inverter 3.

[0022] The drive system 100 configured in this manner is mounted on an electric vehicle such as a hybrid electric vehicle or a pure electric vehicle. That is, the battery cut-off unit 1 is mounted on the electric vehicle together with the battery 2. In this case, DC power output from the battery 2 is supplied to the inverter 3 via the battery cut-off unit 1 as drive energy for running the electric vehicle and is converted into AC power. The AC power output from the inverter 3 is supplied to a motor for rotating and driving the wheels of the vehicle.

[0023] Next, the structure of the battery cutoff unit 1 according to the embodiment will be described with reference to Figs. 2 to 5. Fig. 2 is a perspective view of the battery cutoff unit 1 according to the embodiment. Fig. 2 shows a state in which the upper case 11 is removed. Fig. 3 is an exploded perspective view of the battery cutoff unit 1 according to the embodiment. The upper case 11 is omitted in Fig. 3. Fig. 4 is a cross-sectional view of the battery cutoff unit 1 according to the embodiment. Basically, only the parts that appear in the cross section are shown in Fig. 4. Fig. 5 is a cross-sectional view showing an enlarged main part of the battery cutoff unit 1 according to the embodiment. Specifically, Fig. 5 is an enlarged cross-sectional view of an area V indicated by a dashed line in Fig. 4.

[0024] As shown in FIGS. 2 to 5, the battery cutoff unit 1 includes a case 10, a relay 20, a bus bar 30, a relay cover 40, screws 50, a metal plate 60, and a heat-conducting sheet .

[0025] In addition to the relay 20, the battery cutoff unit 1 may include other electronic components, such as a fuse, such as a pyrotechnic circuit breaker, a current sensor, such as a Hall sensor, and a resistor, such as a shunt resistor.

[0026] The case 10 is a housing that houses components. In the present embodiment, the case 10 houses the relay 20, the bus bar 30, and the relay cover 40. The case 10 also houses other components. The case 10 is an outer casing member of the battery cutoff unit 1.

[0027] 2, case 10 has upper case 11 which is a first cover and lower case 12 which is a second cover. Upper case 11 is combined with lower case 12 so as to cover lower case 12. Components housed in case 10 are mainly arranged in lower case 12. Relay 20 and bus bar 30 are arranged in lower case 12.

[0028] As shown in Figures 2 to 4, in this embodiment, a relay storage section 12a is provided in the lower case 12, and the relay 20 is disposed in the relay storage section 12a. As shown in Figures 3 and 4, the relay storage section 12a is a recess provided in a part of the lower case 12, and a relay housing 22 of the relay 20 is stored in this recess. Specifically, as shown in Figure 4, the rear surface of the relay housing 22 and the bottom surface of the relay storage section 12a, which is the recess, are in surface contact with each other.

[0029] As shown in FIG. 2 and FIG. 3, the lower case 12 is provided with a support portion 12b that supports the relay cover 40. The relay cover 40 is attached to the support portion 12b. The support portion 12b is a part of the lower case 12, and is formed so as to protrude toward the upper case 11. As shown in FIG. 3, specifically, the support portion 12b is formed in a cylindrical shape. A plurality of support portions 12b are provided for one relay cover 40. In this embodiment, three support portions 12b are provided for one relay cover 40. The three support portions 12b are disposed in the vicinity of the relay storage portion 12a. Specifically, the three support portions 12b are provided in a triangular layout so as to surround the relay storage portion 12a. In this embodiment, since two relay covers 40 are disposed, six support portions 12b are provided for the lower case 12.

[0030] Bus bars 30 are fixed to case 10 shown in Figs. 2 to 4. Although details will be described later, the multiple bus bars 30 include bus bars 30 fixed to case 10 by insert molding. In other words, case 10 is a modular case to which bus bars 30 are fixed in advance by insert molding. Specifically, bus bars 30 are fixed to lower case 12 by insert molding. Note that nuts through which screws are inserted when fixing bus bars 30 to lower case 12 later are also fixed to lower case 12 by insert molding. In this way, some of the multiple bus bars 30 and the nuts are integrated into lower case 12 by insert molding.

[0031] Case 10 is a resin-molded product made of a resin material. Case 10 is also made of an insulating material. In the present embodiment, case 10 is made of an insulating resin material. Therefore, case 10 is a housing made of insulating resin. In other words, upper case 11 and lower case 12 constituting case 10 are both resin-molded products made of insulating resin.

[0032] Considering the heat resistance and strength, for example, polyphenylene sulfide (PPS), polybutylene terephthalate (PBT), or an alloy material of polyphenylene ether (PPE) and nylon can be used as the resin material constituting the case 10. The upper case 11 and the lower case 12 may be made of the same resin material or different resin materials.

[0033] The relay 20 housed in the case 10 is an electronic component having a function of turning on and off current flow. Specifically, in FIG. 1, the relay 20 has a function of switching between interruption and supply of DC power supplied from the battery 2 to the battery cutoff unit 1 to the inverter 3. The relay 20 is a mechanical relay (a contact relay). Note that in this embodiment, other types of relays (such as a semiconductor relay or a contactless relay) can also be used for the relay 20, but in order to reliably switch between interruption and supply of a large current from a large-capacity battery mounted on an electric vehicle such as a hybrid electric vehicle or a pure electric vehicle, it is more preferable that the relay 20 be a mechanical relay.

[0034] As shown in Figs. 2 to 5, the relay 20 has a pair of terminals 21 and an insulating relay housing 22 to which the pair of terminals 21 are fixed. The pair of terminals 21 are fixed terminals. The pair of terminals 21 are external connection terminals that are connected to an external member. Specifically, each of the pair of terminals 21 is connected to a bus bar 30. The pair of terminals 21 are metal terminals made of a metal material. The pair of terminals 21 are electrically separated.

[0035] Although not shown, the relay 20 has a movable contactor that comes into contact with and separates from one of a pair of terminals 21, which are fixed terminals. The relay 20 can interrupt or supply a current by making the movable contactor come into contact with or separate from the fixed terminal.

[0036] The relay housing 22 is, for example, a resin housing made of an insulating resin material. As an example, the relay housing 22 is a rectangular parallelepiped having six faces (top, bottom, and four side faces). The movable contact is housed in the relay housing 22.

[0037] 2 and 3, the relay 20 further includes an insulating plate 22a located between the pair of terminals 21. The insulating plate 22a is an insulating wall that separates the pair of terminals 21. Specifically, the insulating plate 22a is a part of the relay housing 22, and is provided in an upright position on the surface of the relay housing 22 on which the terminals 21 are provided.

[0038] In the present embodiment, no mounting portion (collar) for fixing relay housing 22 to case 10 with a screw is provided on the side surface of relay housing 22. In other words, no mounting portion protruding from the side surface of relay housing 22 and provided with a screw hole (a mounting portion protruding from the side surface of relay housing 22X as shown in FIG. 7 described later) is provided on the side surface of relay housing 22.

[0039] As shown in FIG. 2 and FIG. 4, the relay 20 is disposed in the case 10. In this embodiment, the relay 20 is disposed in the lower case 12. Specifically, the relay housing 22 of the relay 20 is housed in the relay storage section 12a provided in the lower case 12. In this case, the relay housing 22 is housed in the relay storage section 12a of the lower case 12 in a horizontal position, and the terminal 21 of the relay 20 is provided on the side of the relay housing 22. That is, as shown in FIG. 2, the relay 20 is disposed so that the terminal 21 faces horizontally, and the terminal 21 faces to the side, not upward (toward the upper case 11). As a result, the insulating plate 22a located between the pair of terminals 21 is also located on the side of the relay housing 22.

[0040] Furthermore, the relay 20 is fixed to the case 10. In this embodiment, the relay 20 is fixed to the lower case 12. In this case, the relay 20 is not directly fixed to the lower case 12, but is fixed to the lower case 12 by a bus bar 30 that is fixed to the lower case 12 in advance. Specifically, as shown in Fig. 2 and Fig. 4, the relay 20 is fixed to the bus bar 30 (relay bus bar 30a) that is fixed to the lower case 12 by screwing the bus bar 30 and the terminal 21 of the relay 20 with screws 50. The relay bus bar 30a and the terminal 21 of the relay 20 are in surface contact with each other.

[0041] At least one relay 20 is disposed in the battery cutoff unit 1. In this embodiment, the battery cutoff unit 1 includes a plurality of relays 20. The plurality of relays 20 includes a first P-side main relay corresponding to the P-side electrode of the battery 2 (see FIG. 1) and a second N-side main relay corresponding to the N-side electrode of the battery 2 (see FIG. 1). Specifically, as shown in FIGS. 2 and 3, two relays 20, the first P-side main relay and the second N-side main relay, are disposed in the case 10. Note that the plurality of relays 20 may include a precharge relay. In addition, when the battery cutoff unit 1 has a quick charge circuit, the plurality of relays 20 may include a first P-side quick charge relay corresponding to the P-side electrode of the battery 2 and a second N-side quick charge relay corresponding to the N-side electrode of the battery 2.

[0042] The bus bar 30 disposed in the case 10 is a wiring member through which a current flows and constitutes a current path. Since the bus bar 30 is a wiring member through which a current flows, it is made of a conductive material. The bus bar 30 also functions as a heat dissipation member (heat sink) for dissipating heat generated by heat-generating components. For example, the bus bar 30 dissipates heat generated by the relay 20, which is one of the heat-generating components. Therefore, the bus bar 30 is preferably made of a metal material such as copper (Cu) or aluminum (Al) in consideration of electrical conductivity and thermal conductivity.

[0043] In addition, in this embodiment, since a large current flows through the bus bar 30, the bus bar 30 is relatively thick. Therefore, the bus bar 30 is a metal rigid body that is thick and has high strength. For example, when the battery cutoff unit 1 is used in a pure electric vehicle, the bus bar 30 may have a thickness exceeding 2 mm, and may further have a thickness of 3 mm or more. Therefore, the bus bar 30 has a thickness that does not bend even when the bus bar 30 is tightened with a screw.

[0044] In the present embodiment, the busbar 30 is made of copper as an example of a metal material. Specifically, the busbar 30 is made of a plate-shaped metal plate made of pure copper or a copper alloy and having a constant thickness. The busbar 30 is formed into a predetermined three-dimensional shape by bending a flat metal plate punched into a predetermined shape by press processing or the like. However, the busbar 30 is not limited to being made of a plate-shaped metal plate, and may be made of, for example, a cast metal conductor (including a case where the metal is an alloy) formed by a casting method (including die casting). In particular, when the busbar 30 is made of a cast metal conductor, the metal material constituting the busbar 30 is not limited to copper, and may be, for example, another metal material such as aluminum.

[0045] It is preferable that a plating film is formed on the surface of the bus bar 30. This can reduce contact resistance. The plating film can be formed by subjecting the bus bar 30 to a plating treatment as a surface treatment. The plating film is, for example, a Ni-Sn plating film made of nickel and tin, but is not limited to this.

[0046] At least one bus bar 30 is disposed in the battery cutoff unit 1. As shown in Figs. 2 and 3, in this embodiment, a plurality of bus bars 30 are disposed in the case 10. As shown in Figs. 2 to 4, the plurality of bus bars 30 include a relay bus bar 30a that is a bus bar 30 connected to the relay 20. In this case, the relay bus bar 30a is connected to the terminal 21 of the relay 20. Specifically, as shown in Figs. 2 and 4, the relay bus bar 30a is fastened to the terminal 21 of the relay 20 by a screw 50. As shown in Figs. 2 and 3, one relay 20 is provided with two terminals 21, and therefore one relay 20 is fixed to two relay bus bars 30a. The two relay bus bars 30a are disposed side by side.

[0047] The multiple bus bars 30 include bus bars 30 that are connected to electronic components other than the relays 20, and connecting bus bars 30 that are not connected to any electronic components and are connected only to other bus bars 30.

[0048] As shown in Fig. 4, each of the two relay bus bars 30a connected to the relay 20 has a first plate portion 31 and a second plate portion 32 standing on the first plate portion 31. The first plate portion 31 and the second plate portion 32 are formed by bending into an L shape. In other words, each relay bus bar 30a has a portion formed in an L shape. However, the shape of the relay bus bar 30a is not limited to this.

[0049] The multiple bus bars 30 are fixed to the case 10. Specifically, the multiple bus bars 30 are fixed to the lower case 12 of the case 10. In this case, the multiple bus bars 30 include bus bars 30 that are directly fixed to the case 10 by insert molding and bus bars 30 that are fixed by screwing into nuts that are fixed to the case 10 by insert molding. In other words, nuts through which screws are inserted when fixing the bus bars 30 to the lower case 12 later are fixed to the lower case 12 by insert molding.

[0050] In this embodiment, at least the relay bus bar 30a connected to the relay 20 is fixed to the case 10 by insert molding. Specifically, the relay bus bar 30a is fixed to the lower case 12 of the case 10 by insert molding. Therefore, a part of the relay bus bar 30a is embedded in a part of the lower case 12. Specifically, as shown in Figs. 4 and 5, a part or the whole of the first plate portion 31 of the bus bar 30, which is the relay bus bar 30a, is embedded in the lower case 12. In this embodiment, the whole of the first plate portion 31 is embedded in the lower case 12. This makes it possible to firmly fix the relay bus bar 30a to the lower case 12. In this embodiment, the first plate portion 31 of the relay bus bar 30a is located below the relay storage portion 12a in the lower case 12.

[0051] 4 and 5, the second plate portion 32 of the bus bar 30, which is the relay bus bar 30a, stands upright relative to the lower case 12. That is, the second plate portion 32 is exposed from the lower case 12 and extends upward (toward the upper case 11) from the lower case 12. An end of the second plate portion 32 faces the terminal 21 of the relay 20. That is, the second plate portion 32 extends at least to the position of the terminal 21 of the relay 20.

[0052] As shown in FIG. 2 and FIG. 4, the terminal 21 of the relay 20 and the bus bar 30 are fixed by the screw 50. In this embodiment, the terminal 21 of the relay 20 and the second plate portion 32 of the bus bar 30, which is the relay bus bar 30a, are fixed by the screw 50. Specifically, as shown in FIG. 3 and FIG. 4, an insertion hole 32a is provided as a screw hole at the end of the second plate portion 32, and the screw 50 inserted into the insertion hole 32a of the second plate portion 32 is screwed into the terminal 21 of the relay 20, thereby fixing the relay bus bar 30a and the relay 20. The insertion hole 32a provided in the second plate portion 32 erected on the first plate portion 31 opens to the side. Therefore, the insertion direction of the screw 50 is a direction parallel to the bottom surface of the lower case 12. The screw 50 is an example of a fastening member, and is a bolt in this embodiment. The screw 50 is not limited to a bolt.

[0053] 2 to 5, the relay cover 40 is a cover that covers the relay 20. Specifically, as shown in Fig. 2 and Fig. 4, the relay cover 40 is arranged so as to cover the relay 20 arranged in the relay storage section 12a of the lower case 12. In the present embodiment, the relay cover 40 covers the relay 20 so that the entire relay housing 22 of the relay 20 is hidden in a top view and a side surface of the relay housing 22 of the relay 20 is exposed in a side view. Therefore, the terminal 21 of the relay 20 is not covered by the relay cover 40 in the insertion direction of the screw 50.

[0054] Further, the relay cover 40 presses the relay 20 against the case 10. Specifically, the relay cover 40 presses the relay housing 22 of the relay 20 arranged in the lower case 12 against the lower case 12. Note that, as shown in Fig. 2, in this embodiment, two relays 20 are arranged in the lower case 12, and therefore two relay covers 40 are arranged on the lower case 12.

[0055] 2, the relay cover 40 is disposed on the top of the support portion 12b provided on the lower case 12, and the relay cover 40 is supported by the support portion 12b. In this embodiment, three support portions 12b are provided for one relay 20, and therefore the relay cover 40 is supported at three points by the three support portions 12b.

[0056] The relay cover 40 arranged on the support portion 12b is fixed to the support portion 12b at the attachment portion 40a. The relay cover 40 is provided with the attachment portion 40a as a portion attached to the support portion 12b. The attachment portion 40a is provided at a position on the relay cover 40 corresponding to the support portion 12b. As shown in FIGS. 2 and 3, in this embodiment, three support portions 12b are provided on the lower case 12, and therefore, one relay cover 40 is provided with three attachment portions 40a. Furthermore, the three attachment portions 40a are provided on the outer periphery of the relay cover 40.

[0057] It should be noted that a number of protrusions are formed on the top surface of the relay cover 40. By providing the protrusions on the relay cover 40 in this manner, wiring (not shown) such as lead wires and harnesses routed inside the case 10 can be hooked or clamped on the protrusions and secured in place, so that the wiring can be easily stored inside the case 10.

[0058] The relay cover 40 is a resin molded product made of an insulating resin material. As with the case 10, the resin material constituting the relay cover 40 may be, for example, PPS, PBT, or an alloy material of PPE and nylon, taking into consideration the heat resistance temperature and strength. The relay cover 40 and the case 10 may be made of the same resin material or different resin materials.

[0059] The relay cover 40 and the case 10 are joined together. Specifically, the mounting portion 40a of the relay cover 40 and the support portion 12b of the lower case 12 are joined together. In this embodiment, the mounting portion 40a of the relay cover 40 and the support portion 12b of the lower case 12 are joined together by ultrasonic welding, heat welding, or laser welding. In this case, the resin constituting the relay cover 40 and the resin constituting the lower case 12 are melted together, thereby joining the mounting portion 40a of the relay cover 40 and the support portion 12b of the lower case 12 together.

[0060] When the relay cover 40 and the lower case 12 are joined by ultrasonic welding, the relay cover 40 and the lower case 12 may be made of the same resin material. In this case, the relay cover 40 and the lower case 12 may be made of a resin material such as an alloy material of PPE and nylon. When the relay cover 40 and the lower case 12 are joined by thermal welding, the relay cover 40 and the lower case 12 may be made of different resin materials or may be made of the same resin material.

[0061] The metal plate 60 is a metal plate made of a metal material. The metal plate 60 is, for example, an aluminum plate made of a metal material mainly composed of aluminum. The metal plate 60 is a flat metal plate. The metal plate 60 may be made of a metal material other than aluminum.

[0062] As shown in FIG. 4 and FIG. 5, the metal plate 60 is disposed below the case 10. That is, the case 10 is disposed above the metal plate 60. Specifically, the lower case 12 of the case 10 is disposed above the metal plate 60. The metal plate 60 is disposed so as to cover the entire lower surface of the lower case 12. The metal plate 60 is fixed to the lower case 12 by a screw. The metal plate 60 constitutes an outer member of the battery cutoff unit 1 together with the case 10. Specifically, the metal plate 60 is a bottom plate of the battery cutoff unit 1, and the lower surface of the metal plate 60 (the surface opposite to the thermal conduction sheet 70 side) is an exposed surface. As a result, the heat conducted to the bus bar 30 and the heat generated at the bus bar 30 are conducted to the metal plate 60, so that the heat conducted to the bus bar 30 and the heat generated at the bus bar 30 can be efficiently dissipated to the outside.

[0063] In particular, in this embodiment, as described above, the multiple bus bars 30 are embedded and fixed in the lower case 12 by insert molding. Therefore, the metal plate 60 and the multiple bus bars 30 embedded in the lower case 12 are in close proximity to each other. This allows the heat conducted to the bus bars 30 embedded in the lower case 12 and the heat generated in the bus bars 30 to be efficiently conducted to the metal plate 60. For example, the heat of the relay 20 conducted to the bus bar 30 (relay bus bar 30a) connected to the relay 20 can be efficiently conducted to the metal plate 60. Therefore, the heat of the relay 20 can be efficiently dissipated.

[0064] The thermal conductivity of the metal plate 60 is preferably higher than that of the thermally conductive sheet 70. In addition, the thickness of the metal plate 60 is preferably greater than the thickness of the thermally conductive sheet 70. This allows the heat conducted to the bus bar 30 and the heat generated in the bus bar 30 to be efficiently conducted to the metal plate 60 via the thermally conductive sheet 70. In this embodiment, the thickness of the metal plate 60 is 4 mm.

[0065] The metal plate 60 is in an electrically floating state (floating state). In other words, no voltage is applied to the metal plate 60, and the current flowing through the bus bar 30 does not flow through the metal plate 60. For this reason, it is preferable that the metal plate 60, which is an outer member, is insulated and separated from the bus bar 30.

[0066] 4 and 5, a heat conductive sheet 70 (thermal sheet) is disposed between the metal plate 60. Specifically, the heat conductive sheet 70 is interposed between the lower case 12 of the case 10 and the metal plate 60. The heat conductive sheet 70 is sandwiched between the lower case 12 and the metal plate 60.

[0067] In the present embodiment, the thermally conductive sheet 70 is in contact with each of the case 10 and the metal plate 60. Specifically, the thermally conductive sheet 70 is in close contact with the lower surface (resin surface) of the lower case 12 of the case 10 and the upper surface (metal surface) of the metal plate 60.

[0068] The thermally conductive sheet 70 conducts the heat conducted to the bus bar 30 fixed to the case 10 and the heat generated at the bus bar 30 to the metal plate 60. Therefore, it is preferable that the thermally conductive sheet 70 is made of a material with high thermal conductivity. As an example, the thermal conductivity of the thermally conductive sheet 70 is 1 W / m·K or more, but is not limited to this.

[0069] The thermally conductive sheet 70 may be made of an insulating material to ensure an insulating state between the metal plate 60 and the bus bar 30. That is, the thermally conductive sheet 70 may be a thin insulating sheet made of an insulating material. The thermally conductive sheet 70 is a resin sheet made of a resin material. In the present embodiment, the thermally conductive sheet 70 is made of a resin material having insulating properties. As an example, a silicone-based or acrylic-based resin material may be used as the resin material constituting the thermally conductive sheet 70.

[0070] The thermally conductive sheet 70 may be made of, for example, an elastomer having rubber elasticity with high thermal conductivity. As a result, the thermally conductive sheet 70 is elastically deformed by being sandwiched between the lower case 12 and the metal plate 60, so that the thermally conductive sheet 70 can be closely attached to the lower case 12 and the metal plate 60.

[0071] From the viewpoint of conducting the heat of the busbar 30 to the metal plate 60 via the thermally conductive sheet 70, it is preferable that the thermally conductive sheet 70 is thin. For example, the thickness of the thermally conductive sheet 70 is preferably 2 mm or less. In the present embodiment, the thickness of the thermally conductive sheet 70 is 1 mm.

[0072] 5, the lower case 12 of the case 10 has a bottom plate portion 12c. The bottom plate portion 12c has a first portion that overlaps with the thermally conductive sheet 70 and a second portion that does not overlap with the thermally conductive sheet 70. The thickness of the first portion of the bottom plate portion 12c that overlaps with the thermally conductive sheet 70 is thinner than the thickness of the second portion of the bottom plate portion 12c that does not overlap with the thermally conductive sheet 70. As an example, the thickness of the first portion of the bottom plate portion 12c that overlaps with the thermally conductive sheet 70 is 0.7 mm, and the thickness of the second portion of the bottom plate portion 12c that does not overlap with the thermally conductive sheet 70 is 1.5 mm.

[0073] In this way, by making the thickness of the first portion of the bottom plate portion 12c that overlaps with the thermally conductive sheet 70 thinner than the thickness of the second portion of the bottom plate portion 12c that does not overlap with the thermally conductive sheet 70, the heat dissipation properties of the battery cut-off unit 1 can be improved while ensuring insulation in both the case 10 and the thermally conductive sheet 70.

[0074] As described above, the battery cut-off unit 1 of this embodiment includes an insulating resin case 10, a relay 20 arranged in the case 10, a bus bar 30 connected to a terminal 21 of the relay 20 and fixed to the case 10 by insert molding, a metal plate 60, and a heat conductive sheet 70 arranged between the case 10 and the metal plate 60.

[0075] In this manner, in the battery cutoff unit 1 according to the present embodiment, the bus bar 30 is fixed to the insulating case 10 by insert molding, so that the insulation of the battery cutoff unit 1 against the bus bar 30 through which a large current flows can be easily ensured. Moreover, since the relay 20 is connected to the bus bar 30 fixed by insert molding, the mechanical connection strength between the relay 20 and the bus bar 30 can be ensured. Furthermore, since the thermally conductive sheet 70 is inserted between the case 10 to which the bus bar 30 (relay bus bar 30a) is fixed by insert molding and the metal plate 60, the heat conducted to the bus bar 30 (relay bus bar 30a) and the heat generated in the bus bar 30 can be efficiently conducted to the metal plate 60 via the thermally conductive sheet 70. For example, as shown by the arrow in FIG. 5, the heat of the relay 20 conducted to the relay bus bar 30a connected to the relay 20 is conducted from the second plate portion 32 to the first plate portion 31 of the relay bus bar 30a, and is further conducted to the metal plate 60 via the thermally conductive sheet 70. In this way, the heat of the bus bar 30 (relay bus bar 30a) can be dissipated efficiently.

[0076] Therefore, the battery cutoff unit 1 according to the present embodiment can achieve both strong connection between the relay 20 and the bus bar 30, heat dissipation properties, and insulation properties.

[0077] In particular, in the battery cutoff unit 1 according to the present embodiment, the thermally conductive sheet 70 contacts both the case 10 and the metal plate 60.

[0078] With this configuration, the heat conducted to the bus bar 30 (relay bus bar 30a) and the heat generated at the bus bar 30 can be conducted more efficiently to the metal plate 60 via the thermally conductive sheet 70. This can further improve the heat dissipation performance of the battery cutoff unit 1.

[0079] In the battery cutoff unit 1 according to the present embodiment, the thermally conductive sheet 70 is made of an insulating resin material.

[0080] With this configuration, not only the case 10 having insulating properties as an insulating member but also the thermally conductive sheet 70 having insulating properties is interposed between the bus bar 30 (relay bus bar 30a) and the metal plate 60, so that the insulation of the battery cut-off unit 1 can be further ensured compared to when the thermally conductive sheet 70 is made of a conductive material.

[0081] It should be noted that a structure in which the heat conductive sheet 70 and the metal plate 60 are insert-formed inside the case 10 (lower case 12) may be considered, but this structure gives rise to the following problems.

[0082] The first problem is that during insert molding, the thermally conductive sheet 70 can only be placed around the bus bar 30 (relay bus bar 30a), which imposes restrictions on the shape of the thermally conductive sheet 70, thereby reducing the heat dissipation performance of the battery cut-off unit 1.

[0083] The second problem is that when the thermally conductive sheet 70 is attached to the metal plate 60 and then insert molded, the heat resistance temperature of the thermally conductive sheet 70 (approximately 130 degrees) is lower than the temperature of the case 10 (lower case 12) during insert molding (resin temperature is approximately 300 degrees), and therefore the thermally conductive sheet 70 deteriorates.

[0084] In contrast, in the battery cutoff unit 1 according to the present embodiment, the thermally conductive sheet 70 is attached externally to the case 10 (lower case 12), and the shapes of the thermally conductive sheet 70 and the metal plate 60 can be freely set. In addition, in the battery cutoff unit 1 according to the present embodiment, the thermally conductive sheet 70 and the metal plate 60 are not formed by inserting them into the inside of the case 10 (lower case 12), but are directly attached (externally attached) below the case 10. In this way, the battery cutoff unit 1 according to the present embodiment does not cause the first and second problems described above, and furthermore, by providing insulation to both the thermally conductive sheet 70 and the case 10, the battery cutoff unit 1 can be made smaller in size.

[0085] Furthermore, in the battery cutoff unit 1 according to the present embodiment, the metal plate 60 is in an electrically floating state.

[0086] With this configuration, the insulation properties of the battery cutoff unit 1 can be further ensured.

[0087] Moreover, in the battery cutoff unit 1 according to this embodiment, the metal plate 60 is an aluminum plate made of a metal material containing aluminum as a main component.

[0088] With this configuration, heat from the bus bar 30 (relay bus bar 30a) can be efficiently conducted to the metal plate 60 via the thermally conductive sheet 70, so that the heat dissipation performance of the battery cutoff unit 1 can be further improved.

[0089] In the battery cutoff unit 1 according to the present embodiment, the metal plate 60 is the bottom plate of the battery cutoff unit 1, and the surface of the metal plate 60 opposite to the thermally conductive sheet 70 is exposed.

[0090] This configuration allows the heat of the bus bar 30 (relay bus bar 30a) conducted to the metal plate 60 to be efficiently dissipated to the atmosphere, thereby further improving the heat dissipation performance of the battery cutoff unit 1.

[0091] Furthermore, in the battery cut-off unit 1 of this embodiment, the bottom plate portion 12c of the case 10 has a first portion that overlaps with the thermally conductive sheet 70 and a second portion that does not overlap with the thermally conductive sheet 70, and the thickness of the first portion is thinner than the thickness of the second portion.

[0092] The resin material constituting the case 10 has a lower thermal conductivity than a metal material. Therefore, by reducing the thickness of a first portion of the bottom plate portion 12c of the case 10 that overlaps with the thermally conductive sheet 70, the heat of the busbar 30 (relay busbar 30a) can be efficiently conducted to the thermally conductive sheet 70. In addition, by increasing the thickness of a second portion of the bottom plate portion 12c of the case 10 that does not overlap with the thermally conductive sheet 70, the mechanical strength of the case 10 to which the busbar 30 is fixed can be ensured. This makes it possible to further achieve a balance between the strength of the connection between the relay 20 and the busbar 30, the heat dissipation property, and the insulation property.

[0093] Next, a manufacturing method of the battery cutoff unit 1 according to the present embodiment will be described with reference to FIG. 6. FIG. 6 is a diagram for explaining the manufacturing method of the battery cutoff unit 1 according to the embodiment. In (a) to (d) of FIG. 6, the left diagram is a side view, and the right diagram is a perspective view. Note that FIG. 6 shows only a part of the configuration of the components that configure the battery cutoff unit 1. For example, only one of the two relays 20 is illustrated, and only the relay bus bar 30a is illustrated for the bus bar 30.

[0094] 6(a), first, the relay 20 is placed in the case 10 to which the bus bar 30 is fixed. Specifically, the relay 20 is placed in the lower case 12 to which multiple bus bars 30 including the relay bus bar 30a are fixed by insert molding. At this time, the relay housing 22 of the relay 20 is placed in the relay storage section 12a of the lower case 12 so that the terminal 21 of the relay 20 and the insertion hole 32a of the relay bus bar 30a are aligned.

[0095] 6(b), the relay cover 40 is placed on the relay 20 placed in the case 10. Specifically, the relay cover 40 is placed on the support portion 12b of the lower case 12 so as to cover the relay housing 22 of the relay 20 placed in the lower case 12. At this time, the relay cover 40 is placed on the support portion 12b so that the mounting portion 40a of the relay cover 40 is positioned on the support portion 12b of the lower case 12. Furthermore, when the relay cover 40 is placed on the support portion 12b, the relay cover 40 and the relay housing 22 of the relay 20 may or may not be in contact with each other.

[0096] 6(c), the relay cover 40 is pressed against the case 10 to fix the relay cover 40 to the case 10. Specifically, the mounting portion 40a of the relay cover 40 and the support portion 12b of the lower case 12 are joined together while pressure is applied from above to below the relay cover 40.

[0097] For example, a pressing member (not shown) is placed on the relay cover 40, and the pressing member is pressed against the relay cover 40 by a pressurizer, thereby joining the mounting portion 40a of the relay cover 40 and the support portion 12b of the lower case 12. The mounting portion 40a of the relay cover 40 and the support portion 12b of the lower case 12 are joined by, for example, ultrasonic waves, heat welding, or laser welding. That is, by applying ultrasonic vibrations, heating, or irradiating the mounting portion 40a of the relay cover 40 with laser light, the resin constituting the relay cover 40 and the resin constituting the lower case 12 are melted, and the mounting portion 40a of the relay cover 40 and the support portion 12b of the lower case 12 are joined.

[0098] At this time, when the relay cover 40 is placed on the support portion 12b (step (b) of Figure 6), even if the relay cover 40 and the relay housing 22 of the relay 20 are not in contact with each other, by joining the relay cover 40 and the support portion 12b of the lower case 12 while applying pressure to the relay cover 40, the relay cover 40 will come into contact with the relay housing 22 and press the relay housing 22 against the lower case 12.

[0099] In this way, by joining the relay cover 40 and the lower case 12 while applying pressure to the relay cover 40, the relay 20 can be held in the lower case 12 with the relay cover 40 pressing the relay 20 against the lower case 12. Furthermore, even if the relay 20 is placed in the lower case 12 at an angle in the step of FIG. 6(a), by joining the relay cover 40 and the lower case 12 while applying pressure to the relay cover 40, the relay cover 40 is flexibly joined to the lower case 12, so that the relay 20 can be held in the lower case 12 by the relay cover 40 without generating stress in the relay 20. In this way, the relay 20 can be stably fixed to the lower case 12 without directly fixing the relay 20 to the lower case 12.

[0100] Next, as shown in (d) of FIG. 6, after the relay cover 40 and the case 10 are fixed together, the terminal 21 of the relay 20 and the bus bar 30 are fixed together with the screw 50. Specifically, the screw 50 is inserted into the insertion hole 32a of the relay bus bar 30a and screwed into the terminal 21 of the relay 20. This allows the relay bus bar 30a and the relay 20 to be electrically and mechanically fixed together. At this time, in the insertion direction of the screw 50, the terminal 21 of the relay 20 is not covered by the relay cover 40. This allows the relay 20 and the relay bus bar 30a to be easily fixed together with the screw 50 even after the relay 20 is covered with the relay cover 40.

[0101] Here, features of the manufacturing method of the battery cutoff unit 1 according to the present embodiment will be described in comparison with a battery cutoff unit 1X of a comparative example with reference to Fig. 7. Fig. 7 is a diagram showing the configuration of the battery cutoff unit 1X of the comparative example.

[0102] As shown in FIG. 7, the battery cutoff unit 1X includes a resin case 10X, and a relay 20X and a bus bar 30X housed in the case 10X.

[0103] In the battery cutoff unit 1X shown in FIG. 7, the relay 20X is fixed to the case 10X. In this case, a bolt is inserted as a screw 51X into an insertion hole of a mounting portion (collar) for fixing provided on a side surface of the relay housing 22X of the relay 20X, and the screw 51X is screwed into a nut 35X embedded in the case 10X. This makes it possible to fix the relay housing 22X of the relay 20X to the case 10X. After the relay 20X is fixed to the case 10X, the bus bar 30X, which is the relay bus bar 30a, is screwed to the terminal 21X of the relay 20X by the screw 52X and to the case 10X by the screw 53X, so that the relay 20X and the relay bus bar 30a can be electrically and mechanically connected and the relay bus bar 30a can be fixed to the case 10X. In FIG. 7, when bus bar 30X, which is relay bus bar 30a, is fixed to case 10X with screw 53X, upper bus bar 30b, which is the upper side bus bar 30X, is placed over relay bus bar 30a, and the upper bus bar 30b and relay bus bar 30a are fastened together with screw 53X.

[0104] In the battery cutoff unit 1X shown in FIG. 7, the case 10X is made of resin, and as shown in FIG. 7, the case 10X may be unintentionally warped or distorted and deformed. If the relay 20X is placed in a part of the case 10X that is deformed in this way, the relay 20X may be fixed to the case 10X in an inclined state. Even if the case 10X is not deformed, the relay 20X may be inclined during assembly, and the relay 20X may be fixed to the case 10X in an inclined state. In this way, in the conventional battery cutoff unit 1X, assembly failure of the relay 20X may occur.

[0105] Furthermore, if an assembly failure occurs in the relay 20X, the bus bar 30X (relay bus bar 30a) connected to the relay 20X may be screwed to the terminal 21X of the relay 20X or fixed to the case 10X in an inclined state. Furthermore, as a result of the relay bus bar 30a being inclined, the upper bus bar 30b which is fastened together with the relay bus bar 30a is also connected in an inclined state relative to the relay bus bar 30a. Thus, in the conventional battery cutoff unit 1X, assembly failure of the bus bar 30X (relay bus bar 30a) may also occur.

[0106] When an assembly failure of the relay bus bar 30a occurs in this way, the relay bus bar 30a does not make surface contact with the terminal 21X of the relay 20X and / or the upper bus bar 30b. In other words, when an assembly failure of the relay bus bar 30a occurs and the relay bus bar 30a tilts, the relay bus bar 30a may be connected to the terminal 21X of the relay 20X in line contact or point contact, or the relay bus bar 30a may be connected to the upper bus bar 30b in line contact or point contact. As a result, although electrical continuity is achieved, the resistance value at the connection portion of the relay bus bar 30a with the terminal 21X of the relay 20X and / or the upper bus bar 30b increases, and this connection portion may become a heat source. Furthermore, at the connection portion of the relay bus bar 30a with the terminal 21X of the relay 20X and / or the upper bus bar 30b, a gap may be generated between the contact surface of the relay bus bar 30a and the contact surface of the terminal 21X of the relay 20X and / or the contact surface of the upper bus bar 30b, which may accelerate corrosion at this connection portion.

[0107] In particular, if the thickness of the busbar 30X (relay busbar 30a) made of copper is 2 mm or less, the relay busbar 30a may be forcibly deformed by bending due to the fastening force when the relay busbar 30a is fastened with the screws 51X and 52X, resulting in surface contact between the busbar 30X and the terminal 21X of the relay 20X and / or the upper busbar 30b. However, if the thickness of the busbar 30X (relay busbar 30a) made of copper exceeds 2 mm (e.g., 3 mm or more), the busbar 30X will not be deformed by the fastening force of the screws, and an assembly defect of the relay busbar 30a will remain as shown in Fig. 7. In a pure electric vehicle, a larger current flows through the busbar 30X than in a hybrid electric vehicle, and therefore a thick busbar 30X having a thickness of 3 mm or more is used instead of a thin busbar 30X having a thickness of 2 mm or less, and therefore an assembly defect of the busbar 30X (relay busbar 30a) is likely to occur.

[0108] Furthermore, if the relay bus bar 30a is improperly assembled and connected to the terminal 21X of the relay 20X in an inclined state, not only will the above-mentioned problems of heat generation and corrosion occur, but stress and distortion will also occur in the relay bus bar 30a and / or the terminal 21X of the relay 20X. If stress and distortion occur in the relay bus bar 30a and / or the terminal 21X of the relay 20X, the long-term reliability of the battery cutoff unit 1X will decrease.

[0109] Thus, in the structure of the battery cutoff unit 1X shown in FIG. 7, when the relay 20X and the bus bar 30X are fixed to the case 10X, the relay 20X and the bus bar 30X may be fixed at an angle, resulting in poor assembly of the relay 20X and the bus bar 30X.

[0110] In contrast, in the manufacturing method of the battery cutoff unit 1 according to the present embodiment, unlike the battery cutoff unit 1X shown in Fig. 7 in which the relay 20X is fixed to the case 10X and then the relay 20X and the bus bar 30X are fastened together, as shown in Fig. 6, the relay 20 is placed in the case 10 to which the bus bar 30 is fixed in advance, the relay 20 is held to the case 10 by a relay cover 40, and then the bus bar 30 and the relay 20 are fastened together by screws 50. Therefore, in the battery cutoff unit 1 according to the present embodiment, unlike the battery cutoff unit 1X shown in Fig. 7, assembly defects of the relay 20 and the bus bar 30 do not occur.

[0111] Moreover, the battery cutoff unit 1 according to this embodiment includes a relay cover 40 that covers the relay 20, and the relay cover 40 presses the relay 20 against the case 10. Furthermore, the terminal 21 of the relay 20 and the bus bar 30 are fixed by a screw 50.

[0112] With this configuration, as described above, the relay 20 is placed in the case 10 to which the bus bar 30 is fixed in advance, and the relay 20 is fixed to the case 10 by the relay cover 40, and then the bus bar 30 (relay bus bar 30a) and the terminal 21 of the relay 20 can be fixed by the screw 50. This makes it possible to hold the relay 20 in the case 10 without causing any rattling in the relay 20, and also makes it possible to fix the relay 20 and the bus bar 30 (relay bus bar 30a) by the screw 50 without applying stress to the relay 20 and the bus bar 30 (relay bus bar 30a). Therefore, the relay 20 and the bus bar 30 can be fixed to the case 10 without causing assembly failure of the relay 20 and the bus bar 30. Therefore, the bus bar 30 (relay bus bar 30a) and the terminal 21 of the relay 20 are in surface contact with each other, so that it is possible to suppress an increase in resistance at the connection portion between the bus bar 30 (relay bus bar 30a) and the terminal 21 of the relay 20, which would cause heat generation or a gap to occur, which would cause accelerated corrosion. Furthermore, since assembly failure of the relay 20 and the bus bar 30 does not occur, the relay 20 can be held in the case 10 without applying stress to the relay 20 and the bus bar 30. This also makes it possible to suppress the occurrence of stress and distortion in the bus bar 30 (relay bus bar 30a) and the terminal 21 of the relay 20. Therefore, a battery cutoff unit 1 with excellent long-term reliability can be realized.

[0113] Moreover, in the battery cutoff unit 1 according to the present embodiment, the terminal 21 of the relay 20 is not covered by the relay cover 40 in the insertion direction of the screw 50. In other words, the terminal 21 of the relay 20 is exposed from the relay cover 40 on the side.

[0114] This allows the relay 20 and the relay bus bar 30 a to be easily fixed with the screws 50 even after the relay 20 is covered with the relay cover 40 .

[0115] As described above, the bus bar 30 (relay bus bar 30a) is fixed to the case 10 by insert molding. Specifically, the relay bus bar 30a is fixed to the lower case 12 by insert molding.

[0116] With this configuration, the bus bar 30 (relay bus bar 30a) and the case 10 can be fixed together in advance, eliminating assembly errors of the bus bar 30. Furthermore, if a nut through which a screw is inserted when fixing the bus bar 30 to the case 10 later is fixed to the case 10 by insert molding, the nut and the relay bus bar 30a can be fixed to the case 10 simultaneously by insert molding. In other words, the relay bus bar 30a can be fixed to the case 10 without adding a separate insert molding process.

[0117] Furthermore, because no stress or distortion occurs in the bus bar 30 (relay bus bar 30a) fixed to the case 10 by insert molding, even when the relay bus bar 30a fixed by insert molding and other bus bars 30 such as an upper bus bar are fastened with screws, the relay bus bar 30a can be in surface contact with the other bus bars 30. In other words, the relay bus bar 30a can be connected to the other bus bars 30 without any gaps being generated in the connection between the relay bus bar 30a and the other bus bars 30.

[0118] In the battery cutoff unit 1 according to the present embodiment, the relay bus bar 30a, which is the bus bar 30 connected to the relay 20, has a first plate portion 31 and a second plate portion 32 standing on the first plate portion 31. A part or the whole of the first plate portion 31 is embedded in the case 10, and the second plate portion 32 and the terminal 21 of the relay 20 are fixed with screws 50.

[0119] With this configuration, the second plate portion 32 of the bus bar 30 is erected from the first plate portion 31 so as to be exposed from the case 10, so that the second plate portion 32 of the bus bar 30 (relay bus bar 30a) and the terminal 21 of the relay 20 can be easily fastened together with screws 50.

[0120] Moreover, in the battery cutoff unit 1 according to the present embodiment, the relay 20 has a relay housing 22, and the terminal 21 is provided on a side surface of the relay housing 22. That is, the relay 20 is disposed so that the terminal 21 faces horizontally.

[0121] With this configuration, the terminal 21 of the relay 20 can be easily faced to the second plate portion 32 standing upright from the first plate portion 31 of the bus bar 30 embedded in the case 10, so that the bus bar 30 and the terminal 21 of the relay 20 can be easily fastened together with the screw 50.

[0122] In the battery cutoff unit 1 according to the present embodiment, the thickness of the bus bar 30 (relay bus bar 30a) is equal to or greater than 3 mm. In other words, the thickness of the bus bar 30 is such that it does not sag even when fastened with a screw.

[0123] If the busbar 30 bends due to the fastening force of the screws, the busbar 30 bends when the busbar 30 and the terminal 21 of the relay 20 are fixed with the screws, so that the busbar 30 and the terminal 21 of the relay 20 can be fixed in surface contact with each other, but if the busbar 30 does not bend due to the fastening force of the screws, an assembly failure of the relay 20 and the busbar 30 occurs, and the busbar 30 and the terminal 21 of the relay 20 cannot be fixed in surface contact with each other. In contrast, in this embodiment, the relay 20 is placed in the case 10 to which the busbar 30 is fixed in advance, and the relay 20 is fixed to the case 10 with the relay cover 40, and then the busbar 30 (relay busbar 30a) and the relay 20 are fixed with the screws 50. As a result, even when a bus bar 30 with a thickness of 3 mm or more (i.e., a bus bar 30 that does not bend due to the tightening force of the screws) is used in conjunction with an increase in current, the relay 20 and the bus bar 30 can be fixed to the case 10 without causing assembly defects of the relay 20 and the bus bar 30. Therefore, the battery cutoff unit 1 according to the present embodiment is suitable for a pure electric vehicle which has a larger current than a hybrid electric vehicle.

[0124] (Modification) Although the technology of the present disclosure has been described above based on the embodiments, the present disclosure is not limited to the above-described embodiments.

[0125] For example, in the above embodiment, the terminal 21 of the relay 20 is provided on the side surface of the relay housing 22, but this is not limiting and the terminal 21 may be provided on the top surface of the relay housing 22. In other words, the relay 20 may be arranged so that the terminal 21 faces upward, rather than facing sideways.

[0126] In the above embodiment, the relay cover 40 and the case 10 are fixed to each other by welding, but this is not limited thereto. For example, the relay cover 40 and the case 10 may be fixed to each other by screws, rivets, or the like.

[0127] In the above embodiment, the relay 20 is pressed down by the relay cover 40 to be held in the case 10, and then the terminal 21 of the relay 20 and the bus bar 30 are fastened together by the screws 50, but this is not limited thereto. For example, the relay 20 and the bus bar 30 arranged in the case 10 to which the bus bar 30 is fixed may be fastened together by the screws 50, and then the relay cover 40 and the case 10 may be joined together to press down the relay 20 and hold it in the case 10.

[0128] In the above embodiment, the battery cutoff unit 1 is used in an electric vehicle, but the present invention is not limited to this. For example, the battery cutoff unit 1 can be applied to electric products such as home appliances.

[0129] Furthermore, the technology of the present disclosure has been applied to the battery cutoff unit 1, but is not limited thereto. The technology of the present disclosure may be used in an electrical junction box other than the battery cutoff unit 1. For example, the technology of the present disclosure may be used in a charging unit connected to a battery. Furthermore, the technology of the present disclosure may be used in an electrical junction box other than a unit connected to a battery, so long as the electrical junction box has a relay.

[0130] In addition, the present disclosure also includes forms obtained by applying various modifications to the above-mentioned embodiments that a person skilled in the art may conceive, and forms realized by arbitrarily combining the components and functions in the embodiments within the scope of the present disclosure. In addition, the present disclosure also includes any combination of two or more claims from among the multiple claims described in the claims at the time of filing of the present application, within the scope of technical compatibility. For example, when a cited-form claim described in the claims at the time of filing of the present application is made into a multiple claim or multiple multiple claim so as to cite all of the higher claims within the scope of technical compatibility, the present disclosure also includes a combination of all claims included in the multiple claim or multiple multiple claim. [Industrial Applicability]

[0131] The technology disclosed herein can be widely used in various products such as automobiles or electrical appliances. [Explanation of symbols]

[0132] 1 Battery disconnect unit 2 Battery 3 Inverter 10 Cases 11 Upper case 12 Lower case 12a Relay storage section 12b Support part 12c Bottom plate part 20 Relay 21 Terminal 22 Relay housing 22a Insulating plate 30 Busbar (metal conductor) 31 1st plate part 32 2nd plate part 32a Insertion hole 30a relay busbar 40 Relay cover 40a Mounting part 50 Screw 60 Metal Plate 70 Thermal Conductive Sheet 100 Drive System

Claims

1. placing a relay in a case to which the busbar is fixed; placing a relay cover over the relay disposed in the case; fixing the relay cover to the case in a state where the relay cover is pressed against the case; and after the relay cover and the case are fixed together, fixing the terminals of the relay and the bus bars with screws. A manufacturing method for an electrical junction box.

2. The relay cover and the case are joined by ultrasonic waves or welding. A method for manufacturing the electrical junction box according to claim 1.

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