Electrical connection box and method for manufacturing electrical connection box

Abstract

A battery cut-off unit (1), which is an example of an electrical connection box, is provided with: a resin case (10) having insulating properties; a relay (20) disposed in the housing (10); a bus bar (30) connected to a terminal (21) of the relay (20) and fixed to the housing (10) by insert molding; a metal plate (60); and a thermally conductive sheet (70) disposed between the housing (10) and the metal plate (60).

Description

TECHNICAL FIELD

[0001] The present disclosure relates to an electrical connection box such as a battery disconnect unit and a manufacturing method of an electrical connection box. BACKGROUND

[0002] In an electric automobile such as a hybrid electric automobile or a pure electric automobile, a battery for a power supply is mounted, and an electrical connection box for connecting the battery and various electrical devices is mounted (Patent Literature 1).

[0003] As such an electrical connection box, a battery disconnect unit (BDU: Battery Disconnect Unit) is known. The battery disconnect unit has a relay that cuts off or supplies electric power output from a battery. For example, the battery disconnect unit has a housing made of resin, a relay housed in the housing, and a bus bar connected to a terminal of the relay.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: Japanese Patent Application Laid-Open No. 2005-210804 SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] However, in the conventional battery disconnect unit, the connection reliability of the terminal (fixed terminal) of the relay to the bus bar is insufficient.

[0009] In addition, in the battery disconnect unit, heat is generated from the relay as a power device, but since the distance from the terminal of the relay to the external heat sink is long, it is difficult to sufficiently dissipate the heat generated by the relay. In particular, when the current is sharply discharged from the battery due to short-time sudden acceleration of the electric automobile or the like, the relay becomes high temperature.

[0010] Further, in the battery disconnect unit, since a large current flows in the bus bar, it is important to ensure the insulation, but depending on the insulation structure, it becomes a factor that hinders the dissipation of heat generated by the relay.

[0011] Thus, in the conventional battery disconnect unit, there is a problem that it is difficult to balance the connection reliability of the relay and the bus bar, the heat dissipation, and the insulation.

[0012] The present disclosure was made to solve such a problem, and aims to provide an electrical connection box and a manufacturing method of an electrical connection box that can balance the connection reliability of the relay and the bus bar, the heat dissipation, and the insulation.

[0013] MEANS FOR SOLVING THE PROBLEMS

[0014] To achieve the above object, one aspect of the electric connection box of the present disclosure includes: a housing made of resin, having insulating properties; a relay disposed in the housing; a bus bar connected to a terminal of the relay, fixed to the housing by insert molding; a metal plate; and a heat dissipation sheet disposed between the housing and the metal plate.

[0015] Further, one aspect of the manufacturing method of the electric connection box of the present disclosure includes: a step of disposing a relay in a housing in which a bus bar is fixed; a step of disposing a relay cover on the relay disposed in the housing; a step of fixing the relay cover to the housing while pressing the relay cover toward the housing; and a step of fixing a terminal of the relay to the bus bar by a screw after fixing the relay cover to the housing.

[0016] Effects of the Invention

[0017] According to the present disclosure, it is possible to achieve both the connection strength of the relay and the bus bar, the heat dissipation, and the insulation. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a block diagram of a drive system of an embodiment.

[0019] Figure 2 is a perspective view of a battery cutoff unit of an embodiment.

[0020] Figure 3 is an exploded perspective view of a battery cutoff unit of an embodiment.

[0021] Figure 4 is a sectional view of a battery cutoff unit of an embodiment.

[0022] Figure 5 is a sectional view of a battery cutoff unit of an embodiment.

[0023] Figure 6 is a diagram for explaining a manufacturing method of a battery cutoff unit of an embodiment.

[0024] Figure 7 is a diagram showing a structure of a battery cutoff unit of a comparative example. DETAILED DESCRIPTION

[0025] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Further, each of the embodiments described below indicates one specific example of the present disclosure. Therefore, numerical values, constituent elements, arrangement positions and connection modes of the constituent elements, and procedures and order of the procedures and the like shown in the following embodiments are one example, and are not intended to limit the present disclosure. Therefore, with respect to the constituent elements of the following embodiments, the constituent elements not recited in the independent technical solution are described as arbitrary constituent elements.

[0026] Further, each drawing is a schematic view and is not necessarily strictly illustrated. In addition, in each drawing, the same reference signs are attached to substantially the same structures, and repetitive explanations are omitted or simplified. In addition, in the present specification, terms such as "upper" and "lower" do not necessarily refer to upward and downward directions in absolute spatial recognition (plumb upward and plumb downward).

[0027] Embodiment

[0028] First, as one example of a system using the battery cutoff unit 1 of the embodiment, a drive system 100 will be described. Figure 1 is a block diagram of the drive system 100 of the embodiment.

[0029] As Figure 1 shown, the drive system 100 is provided with the battery cutoff unit 1, the battery 2, and the inverter 3.

[0030] The battery cutoff unit 1 is one example of an electrical connection box for connecting the battery 2 and various electrical equipment. For example, the battery cutoff unit 1 is connected between the battery 2 and the inverter 3, and cuts off or supplies the direct-current electric power output from the battery 2 to the inverter 3. That is, the battery cutoff unit 1 can switch between a power supply state of supplying electric power to the inverter 3 and a power cutoff state of cutting off electric power to the inverter 3.

[0031] Further, although not illustrated, the battery cutoff unit 1 can be connected not only to the inverter 3 but also to a quick charging circuit. In this case, the battery cutoff unit 1 can switch the output destination of the direct-current electric power output from the battery 2 to the inverter 3 or the quick charging circuit. In addition, the battery cutoff unit 1 can also switch between a power supply state of supplying electric power to the quick charging circuit and a power cutoff state of cutting off electric power to the quick charging circuit. In addition, as another mode, the quick charging circuit can also be mounted on the battery cutoff unit 1.

[0032] The battery 2 is an electrical storage device such as a secondary battery. Direct-current electric power is output from the battery 2. Therefore, the battery 2 connected to the battery cutoff unit 1 supplies direct-current electric power to the battery cutoff unit 1. The battery 2 is, for example, a lithium ion secondary battery, but is not limited thereto.

[0033] The inverter 3 is an AC / DC converter that converts the direct-current electric power supplied from the battery cutoff unit 1 into alternating-current electric power. Although not shown, the inverter 3 is connected to a motor, for example, and the motor connected to the inverter 3 is driven by the alternating-current electric power output from the inverter 3.

[0034] The driving system 100 configured as such is mounted on an electric vehicle such as a hybrid electric vehicle or a pure electric vehicle, for example. That is, the battery cutoff unit 1 is mounted on the electric vehicle together with the battery 2. In this case, the direct-current electric power output from the battery 2 is supplied to the inverter 3 via the battery cutoff unit 1 as driving energy for running of the electric vehicle and is converted into alternating-current electric power. The alternating-current electric power output from the inverter 3 is supplied to a motor for rotationally driving a wheel of the vehicle.

[0035] Next, the structure of the battery cutoff unit 1 of the embodiment will be described using Figures 2-5 Figure 2 is a perspective view of the battery cutoff unit 1 of the embodiment. In Figure 2 , a state in which the upper case 11 is removed is shown. Figure 3 is an exploded perspective view of the battery cutoff unit 1 of the embodiment. In Figure 3 , the upper case 11 is omitted. Figure 4 is a sectional view of the battery cutoff unit 1 of the embodiment. In Figure 4 , only the portion indicated in the cross section is shown. Figure 5 is an enlarged sectional view that shows a main portion of the battery cutoff unit 1 of the embodiment. Specifically, Figure 5 is an enlarged sectional view of the area V shown by the broken line in Figure 4

[0036] As shown in Figures 2-5 , the battery cutoff unit 1 is provided with a case 10, a relay 20, a bus bar 30, a relay cover 40, a screw 50, a metal plate 60, and a heat-conducting sheet 70.

[0037] Further, the battery cutoff unit 1 can be provided with a fuse such as a pyrotechnic fuse (pyrotechnic cutoff), a current sensor such as a Hall sensor, and a resistor such as a shunt resistor, in addition to the relay 20.

[0038] The case 10 is a frame that houses components. In the present embodiment, the case 10 houses the relay 20, the bus bar 30, and the relay cover 40. In addition, components other than these are also housed in the case 10. The case 10 is an outer contour member of the battery cutoff unit 1.

[0039] As shown in Figure 2 ​​As shown, the housing 10 includes an upper housing 11 serving as a first cover and a lower housing 12 serving as a second cover. The upper housing 11 is assembled with the lower housing 12 so as to cover the lower housing 12. The components housed in the housing 10 are primarily located in the lower housing 12. The relay 20 and bus bar 30 are located in the lower housing 12.

[0040] like Figures 2-4 As shown in FIG. 1 , in this embodiment, a relay storage portion 12a is provided in the lower housing 12, and the relay 20 is disposed in the relay storage portion 12a. Figure 3 and Figure 4 As shown, the relay receiving portion 12a is a recessed portion provided in a portion of the lower housing 12, and the relay frame 22 of the relay 20 is received in the recessed portion. Figure 4 As shown, the rear surface of the relay housing 22 is in surface contact with the bottom surface of the relay housing portion 12a, which is a recessed portion.

[0041] In addition, if Figure 2 as well as Figure 3 As shown, the lower housing 12 is provided with a support portion 12b that supports the relay cover 40. The relay cover 40 is mounted on the support portion 12b. The support portion 12b is a part of the lower housing 12 and is formed to protrude toward the upper housing 11. Figure 3 As shown, specifically, the support portion 12b is formed into a cylindrical shape. Multiple support portions 12b are provided for each relay cover 40. In this embodiment, three support portions 12b are provided for each relay cover 40. The three support portions 12b are arranged near the relay storage portion 12a. Specifically, the three support portions 12b are arranged in a triangular layout to surround the relay storage portion 12a. Furthermore, in this embodiment, since two relay covers 40 are provided, six support portions 12b are provided in the lower housing 12.

[0042] exist Figures 2-4 The housing 10 shown is fixed with a busbar 30. As will be described in detail later, the plurality of busbars 30 include a busbar 30 fixed to the housing 10 by insert molding. That is, the housing 10 is a module housing to which the busbar 30 is previously fixed by insert molding. Specifically, the busbar 30 is fixed to the lower housing 12 by insert molding. In addition, a nut is also fixed to the lower housing 12 by insert molding, and the nut is inserted when the screw is installed to fix the busbar 30 to the lower housing 12. In this way, some of the plurality of busbars 30 and the nut are integrated with the lower housing 12 by insert molding.

[0043] The housing 10 is a resin molded article made of a resin material. Furthermore, the housing 10 is made of an insulating material. In this embodiment, the housing 10 is made of an insulating resin material. Therefore, the housing 10 is an insulating resin frame. Specifically, the upper housing 11 and the lower housing 12 that constitute the housing 10 are both insulating resin molded articles.

[0044] As the resin material constituting the housing 10, for example, polyphenylene sulfide (PPS), polybutylene terephthalate (PBT), or an alloy of polyphenylene ether (PPE) and nylon can be used, taking into account heat resistance and strength. The upper housing 11 and the lower housing 12 can be made of the same resin material or different resin materials.

[0045] The relay 20 housed in the housing 10 is an electronic component having the function of turning the power on and off. Figure 1 In the embodiment, the relay 20 has the function of switching between supplying and disconnecting the DC power supplied from the battery 2 to the battery disconnect unit 1 to the inverter 3. Furthermore, the relay 20 is a mechanical relay (a contact relay). In this embodiment, other relay types (for example, semiconductor relays and contactless relays) can be used as the relay 20. However, in order to reliably switch between supplying and disconnecting the large current from the large-capacity battery mounted in electric vehicles such as hybrid electric vehicles and pure electric vehicles, the relay 20 is more preferably a mechanical relay.

[0046] like Figures 2-5 As shown, relay 20 includes a pair of terminals 21 and an insulating relay frame 22 that secures the terminals 21. Terminals 21 are fixed terminals. Furthermore, terminals 21 are external connection terminals for connection to external components. Specifically, terminals 21 are each connected to busbar 30. Terminals 21 are metal terminals made of metal material. Terminals 21 are electrically isolated.

[0047] Although not shown, the relay 20 includes a movable contact that contacts and separates from one of a pair of fixed terminals 21. The relay 20 can interrupt or supply current by contacting or separating the movable contact with the fixed terminal.

[0048] The relay housing 22 is a resin housing made of, for example, an insulating resin material. For example, the relay housing 22 is a rectangular parallelepiped having six surfaces (a top surface, a bottom surface, and four side surfaces). The movable contact is housed in the relay housing 22 .

[0049] like Figure 2 and Figure 3As shown, the relay 20 also has an insulating plate 22a 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 portion of the relay housing 22, and is disposed in an upright posture in the relay housing 22, on the face on which the terminals 21 are disposed.

[0050] Further, in the present embodiment, no mounting portion (collar) for fixing the relay housing 22 to the case 10 by a screw is provided on the side surface of the relay housing 22. That is, no mounting portion (the mounting portion protruding from the side surface of the relay housing 22X, which will be described later, which is provided with a threaded hole) is provided on the side surface of the relay housing 22. Figure 7

[0051] As shown, the relay 20 is disposed in the case 10. In the present 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 housing portion 12a provided in the lower case 12. In this case, the relay housing 22 is housed in the relay housing portion 12a of the lower case 12 in a landscape posture, and the terminals 21 of the relay 20 are disposed on the side surface of the relay housing 22. That is, as shown, the relay 20 is disposed in such a manner that the terminals 21 are in a landscape posture, and the terminals 21 are not directed upward (the upper case 11 side) but are directed sideways. Thus, the insulating plate 22a between the pair of terminals 21 is also located on the side surface of the relay housing 22. Figure 2 Figure 4 Figure 2

[0052] Further, the relay 20 is fixed to the case 10. In the present 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 via the bus bar 30 that is preliminarily fixed to the lower case 12. Specifically, as shown, the relay 20 is fixed to the bus bar 30 by screwing the bus bar 30 (relay bus bar 30a) fixed to the lower case 12 and the terminals 21 of the relay 20 with the screw 50. The relay bus bar 30a is in surface contact with the terminals 21 of the relay 20. Figure 2 Figure 4

[0053] The battery cutoff unit 1 is provided with at least one relay 20. In the present embodiment, the battery cutoff unit 1 is provided with a plurality of relays 20. Among the plurality of relays 20, there are included a first main relay on the P side corresponding to the electrode on the P side of the battery 2 (refer to Figure 1 ), and a second main relay on the N side corresponding to the electrode on the N side of the battery 2 (refer to Figure 1 ). Specifically, as shown, there are included a first main relay on the P side and a second main relay on the N side. Figure 2 Figure 3 ​​​​​​​As shown, two relays 20 are arranged in the housing 10: a first main relay on the P side and a second main relay on the N side. Furthermore, a pre-charge relay may be included among the plurality of relays 20. Furthermore, if the battery disconnect unit 1 includes a rapid charging circuit, the plurality of relays 20 may also include a first rapid charging relay on the P side corresponding to the P-side electrode of the battery 2 and a second rapid charging relay on the N side corresponding to the N-side electrode of the battery 2.

[0054] The busbar 30 disposed in the housing 10 is a wiring member for the flow of electric current and constitutes an electrical path. The busbar 30 is a wiring member for the flow of electric current and is therefore made of a conductive material. In addition, the busbar 30 also functions as a heat dissipation member (heat sink) for dissipating heat generated by a heat-generating component. For example, the busbar 30 dissipates heat generated by the relay 20, which is one of the heat-generating components. Therefore, considering electrical conductivity and thermal conductivity, the busbar 30 can be made of a metal material such as copper (Cu) or aluminum (Al).

[0055] Furthermore, in this embodiment, since a large current flows through the busbar 30, the busbar 30 is relatively thick. Therefore, the busbar 30 is a thick, high-strength metallic rigid body. For example, when the battery disconnect unit 1 is used in a pure electric vehicle, the busbar 30 can be thicker than 2 mm, or even thicker than 3 mm. Consequently, the busbar 30 is thick enough to prevent deflection even when screws are used to fasten the busbar 30.

[0056] In the present embodiment, as an example of a metal material, the busbar 30 is made of copper. Specifically, the busbar 30 is made of a plate-shaped metal plate of constant thickness made of pure copper or a copper alloy. The busbar 30 is formed into a three-dimensional prescribed shape by bending a flat metal plate punched into a prescribed shape using a stamping process or the like. However, the busbar 30 is not limited to being made of a plate-shaped metal plate, and for example, it may be made of a cast metal conductor (including a case where the metal is an alloy) formed by a casting method (including die casting). In particular, in the case where 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 other metal materials such as aluminum.

[0057] A plating film is preferably formed on the surface of the bus bar 30. This can reduce contact resistance. The plating film can be formed by plating the bus bar 30 as a surface treatment. The plating film is, for example, a Ni—Sn plating film composed of nickel tin, but is not limited thereto.

[0058] At least one bus bar 30 is provided in the battery disconnection unit 1. Figure 2 and Figure 3As shown in FIG. 1 , in this embodiment, a plurality of bus bars 30 are arranged in the housing 10. Figures 2-4 As shown, the plurality of bus bars 30 include a relay bus bar 30a as 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 FIG. Figure 2 and Figure 4 As shown, the relay bus bar 30a is fastened to the terminal 21 of the relay 20 by means of screws 50. Figure 2 and Figure 3 As shown, 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 arranged side by side.

[0059] The plurality of bus bars 30 include bus bars 30 connected to electronic components other than the relays 20 and connecting bus bars 30 that are not connected to electronic components but are connected only to other bus bars 30 .

[0060] like Figure 4 As shown, the two relay busbars 30a connected to the relay 20 each include a first plate portion 31 and a second plate portion 32 disposed upright 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 busbar 30a has an L-shaped portion. The shape of the relay busbar 30a is not limited to this.

[0061] Multiple busbars 30 are fixed to the housing 10. Specifically, the multiple busbars 30 are fixed to the lower housing 12 of the housing 10. In this case, the multiple busbars 30 include busbars 30 that are directly fixed to the housing 10 by insert molding, and busbars 30 that are fixed by screws screwed into nuts fixed to the housing 10 by insert molding. In other words, nuts are fixed to the lower housing 12 by insert molding, and these nuts are inserted with screws when fixing the busbars 30 to the lower housing 12 through post-installation.

[0062] In this embodiment, at least the relay bus bar 30a connected to the relay 20 is fixed to the housing 10 by insert molding. Specifically, the relay bus bar 30a is fixed to the lower housing 12 of the housing 10 by insert molding. Therefore, a portion of the relay bus bar 30a is embedded in a portion of the lower housing 12. Specifically, as shown in FIG. Figure 4 and Figure 5As shown, a part or all of the first plate portion 31 of the bus bar 30 as the relay bus bar 30a is embedded in the lower case 12. In the present embodiment, all of the first plate portion 31 is embedded in the lower case 12. Thereby, the relay bus bar 30a can be firmly fixed to the lower case 12. Further, in the present embodiment, the first plate portion 31 of the relay bus bar 30a is positioned below the relay housing portion 12a in the lower case 12.

[0063] Further, as shown in Figs. 1 and 2, the second plate portion 32 of the bus bar 30 as the relay bus bar 30a is vertically provided with respect to the lower case 12. That is, the second plate portion 32 is exposed from the lower case 12 and extends from the lower case 12 toward the upper side (the upper case 11 side). The end portion of the second plate portion 32 is opposed to 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. Figure 4 Figure 5 Further, as shown in Figs. 1 and 2, the second plate portion 32 of the bus bar 30 as the relay bus bar 30a is vertically provided with respect to the lower case 12. That is, the second plate portion 32 is exposed from the lower case 12 and extends from the lower case 12 toward the upper side (the upper case 11 side). The end portion of the second plate portion 32 is opposed to 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.

[0064] As shown in Figs. 1 and 2, the terminal 21 of the relay 20 and the bus bar 30 are fixed by the screw 50. In the present embodiment, the terminal 21 of the relay 20 and the second plate portion 32 of the bus bar 30 as the relay bus bar 30a are fixed by the screw 50. Specifically, as shown in Figs. 1 and 2, the through-hole 32a as a threaded hole is provided at the end portion of the second plate portion 32, and the screw 50 inserted through the through-hole 32a of the second plate portion 32 is screwed into the terminal 21 of the relay 20, whereby the relay bus bar 30a and the relay 20 can be fixed. Figure 2 Figure 4 As shown in Figs. 1 and 2, the terminal 21 of the relay 20 and the bus bar 30 are fixed by the screw 50. In the present embodiment, the terminal 21 of the relay 20 and the second plate portion 32 of the bus bar 30 as the relay bus bar 30a are fixed by the screw 50. Specifically, as shown in Figs. 1 and 2, the through-hole 32a as a threaded hole is provided at the end portion of the second plate portion 32, and the screw 50 inserted through the through-hole 32a of the second plate portion 32 is screwed into the terminal 21 of the relay 20, whereby the relay bus bar 30a and the relay 20 can be fixed. Figure 3 Figure 4 As shown in Figs. 1 and 2, the terminal 21 of the relay 20 and the bus bar 30 are fixed by the screw 50. In the present embodiment, the terminal 21 of the relay 20 and the second plate portion 32 of the bus bar 30 as the relay bus bar 30a are fixed by the screw 50. Specifically, as shown in Figs. 1 and 2, the through-hole 32a as a threaded hole is provided at the end portion of the second plate portion 32, and the screw 50 inserted through the through-hole 32a of the second plate portion 32 is screwed into the terminal 21 of the relay 20, whereby the relay bus bar 30a and the relay 20 can be fixed.

[0065] As shown in Figs. 1 and 2, the terminal 21 of the relay 20 and the bus bar 30 are fixed by the screw 50. In the present embodiment, the terminal 21 of the relay 20 and the second plate portion 32 of the bus bar 30 as the relay bus bar 30a are fixed by the screw 50. Specifically, as shown in Figs. 1 and 2, the through-hole 32a as a threaded hole is provided at the end portion of the second plate portion 32, and the screw 50 inserted through the through-hole 32a of the second plate portion 32 is screwed into the terminal 21 of the relay 20, whereby the relay bus bar 30a and the relay 20 can be fixed. Figures 2-5 Figure 2 As shown in Figs. 1 and 2, the terminal 21 of the relay 20 and the bus bar 30 are fixed by the screw 50. In the present embodiment, the terminal 21 of the relay 20 and the second plate portion 32 of the bus bar 30 as the relay bus bar 30a are fixed by the screw 50. Specifically, as shown in Figs. 1 and 2, the through-hole 32a as a threaded hole is provided at the end portion of the second plate portion 32, and the screw 50 inserted through the through-hole 32a of the second plate portion 32 is screwed into the terminal 21 of the relay 20, whereby the relay bus bar 30a and the relay 20 can be fixed. Figure 4 As shown in Figs. 1 and 2, the terminal 21 of the relay 20 and the bus bar 30 are fixed by the screw 50. In the present embodiment, the terminal 21 of the relay 20 and the second plate portion 32 of the bus bar 30 as the relay bus bar 30a are fixed by the screw 50. Specifically, as shown in Figs. 1 and 2, the through-hole 32a as a threaded hole is provided at the end portion of the second plate portion 32, and the screw 50 inserted through the through-hole 32a of the second plate portion 32 is screwed into the terminal 21 of the relay 20, whereby the relay bus bar 30a and the relay 20 can be fixed.

[0066] ​​​​Further, the relay cover 40 presses the relay 20 against the case 10. Specifically, the relay cover 40 presses the relay frame 22 of the relay 20 arranged on the lower case 12 against the lower case 12. Further, as shown in Figure 2 In the present embodiment, two relays 20 are arranged on the lower case 12, and therefore two relay covers 40 are arranged on the lower case 12.

[0067] As shown in Figure 2 The relay cover 40 arranged on the support portion 12b provided on the lower case 12 is supported on the support portion 12b. In the present embodiment, three support portions 12b are provided with respect to one relay 20, and therefore the relay cover 40 is supported by the three support portions 12b by three-point support.

[0068] The relay cover 40 arranged on the support portion 12b is fixed to the support portion 12b in the mounting portion 40a. The mounting portion 40a is provided on the relay cover 40 as a portion to be mounted on the support portion 12b. The mounting portion 40a is provided on the relay cover 40 at a position corresponding to the support portion 12b. As shown in Figure 2 and Figure 3 In the present embodiment, three support portions 12b are provided on the lower case 12, and therefore three mounting portions 40a are provided on one relay cover 40. Further, the three mounting portions 40a are provided on the outer peripheral portion of the relay cover 40.

[0069] Further, a plurality of protrusions are formed on the upper surface of the relay cover 40. In this way, by providing the protrusions on the relay cover 40, the wiring (not shown) such as a lead wire or a wire harness routed inside the case 10 can be hooked or clamped to the protrusions to be fixed, and therefore the wiring can be easily housed inside the case 10.

[0070] The relay cover 40 is a resin molded product composed of a resin material having insulating properties. As the resin material composing the relay cover 40, in consideration of heat resistance temperature and strength, similarly to the case 10, for example, PPS, PBT, or an alloy material of PPE and nylon, or the like can be used. Further, the relay cover 40 and the case 10 can be composed of the same resin material or different resin materials.

[0071] The relay cover 40 is joined to the case 10. Specifically, the mounting portion 40a of the relay cover 40 is joined to the support portion 12b of the lower case 12. In the present embodiment, the mounting portion 40a of the relay cover 40 is joined to the support portion 12b of the lower case 12 by ultrasonic welding, heat welding, or laser welding. In this case, the resin composing the relay cover 40 and the resin composing the lower case 12 are melted, and thereby the mounting portion 40a of the relay cover 40 is joined to the support portion 12b of the lower case 12.

[0072] Furthermore, when the relay cover 40 and the lower case 12 are joined by ultrasonic welding, the relay cover 40 and the lower case 12 can be made of the same resin material. In this case, the relay cover 40 and the lower case 12 can be made of, for example, a resin material such as an alloy of PPE and nylon. Furthermore, when the relay cover 40 and the lower case 12 are joined by thermal welding, the relay cover 40 and the lower case 12 can be made of different resin materials, or they can be made of the same resin material.

[0073] The metal plate 60 is a metal plate made of a metal material. For example, the metal plate 60 is an aluminum plate made of a metal material mainly composed of aluminum. The metal plate 60 is a flat metal plate. In addition, the metal plate 60 can also be made of a metal material other than aluminum.

[0074] like Figure 4 and Figure 5 As shown, the metal plate 60 is arranged below the shell 10. That is, the shell 10 is arranged above the metal plate 60. Specifically, the lower shell 12 of the shell 10 is arranged above the metal plate 60. The metal plate 60 is arranged in a manner that covers the entire lower surface of the lower shell 12. The metal plate 60 is fixed to the lower shell 12 by screws. The metal plate 60 and the shell 10 together constitute the outer frame member of the battery cut-off unit 1. Specifically, the metal plate 60 is the bottom plate of the battery cut-off unit 1, and the lower surface of the metal plate 60 (the surface on the side opposite to the heat conductive sheet 70) becomes an exposed surface. As a result, the heat conducted to the bus bar 30 and the heat generated by 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 by the bus bar 30 can be efficiently dissipated to the outside.

[0075] In particular, in this embodiment, as described above, multiple bus bars 30 are embedded and fixed in the lower case 12 by insert molding. Therefore, the metal plate 60 is close to the multiple bus bars 30 embedded in the lower case 12. This allows heat transferred to the bus bars 30 embedded in the lower case 12, as well as heat generated by the bus bars 30, to be efficiently transferred to the metal plate 60. For example, heat from the relay 20 that is transferred to the bus bar 30 (relay bus bar 30a) connected to the relay 20 can be efficiently transferred to the metal plate 60. Consequently, heat from the relay 20 can be efficiently dissipated.

[0076] The thermal conductivity of the metal plate 60 can be higher than that of the thermally conductive sheet 70. Furthermore, the thickness of the metal plate 60 can be thicker than that of the thermally conductive sheet 70. This allows heat conducted to the bus bar 30 and heat generated by 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.

[0077] The metal plate 60 becomes in an electrically floating state (floating state). That is, no voltage is applied to the metal plate 60, and no current flowing through the bus bar 30 flows in the metal plate 60. Therefore, the metal plate 60, which is an outer member, can be insulated and separated from the bus bar 30.

[0078] As shown in FIG. 1, a thermally conductive sheet 70 (heat-sensitive sheet) is disposed between the metal plate 60 and the housing 10. Specifically, the thermally conductive sheet 70 is interposed between the lower housing 12 of the housing 10 and the metal plate 60. The thermally conductive sheet 70 is sandwiched by the lower housing 12 and the metal plate 60. Figure 4 Figure 5 As shown in FIG. 1, a thermally conductive sheet 70 (heat-sensitive sheet) is disposed between the metal plate 60 and the housing 10. Specifically, the thermally conductive sheet 70 is interposed between the lower housing 12 of the housing 10 and the metal plate 60. The thermally conductive sheet 70 is sandwiched by the lower housing 12 and the metal plate 60.

[0079] In the present embodiment, the thermally conductive sheet 70 is in contact with the housing 10 and the metal plate 60, respectively. Specifically, the thermally conductive sheet 70 is in close contact with the lower surface (resin surface) of the lower housing 12 of the housing 10 and the upper surface (metal surface) of the metal plate 60.

[0080] The thermally conductive sheet 70 conducts heat to the metal plate 60 from the bus bar 30 fixed to the housing 10 and heat generated by the bus bar 30. Therefore, the thermally conductive sheet 70 can be composed of a material having a 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 thereto.

[0081] In order to ensure an insulating state of the metal plate 60 from the bus bar 30, the thermally conductive sheet 70 can be composed of an insulating material. That is, the thermally conductive sheet 70 can be a thin insulating sheet in a sheet shape composed of an insulating material. In addition, the thermally conductive sheet 70 is a resin sheet composed of a resin material. In the present embodiment, the thermally conductive sheet 70 is composed of a resin material having insulating properties. As an example, as the resin material constituting the thermally conductive sheet 70, a silicone-based or acrylic-based resin material can be used.

[0082] The thermally conductive sheet 70 can be composed of an elastomer having rubber elasticity having a high thermal conductivity, for example. Thereby, the thermally conductive sheet 70 is elastically deformed by being sandwiched by the lower housing 12 and the metal plate 60, and thus the thermally conductive sheet 70 can be brought into close contact with the lower housing 12 and the metal plate 60.

[0083] From the viewpoint of conducting heat of the bus bar 30 to the metal plate 60 via the thermally conductive sheet 70, the thickness of the thermally conductive sheet 70 is preferably thin. For example, the thickness of the thermally conductive sheet 70 can be 2 mm or less. In the present embodiment, the thickness of the thermally conductive sheet 70 is 1 mm.

[0084] In addition, as shown in FIG. 1, the thermally conductive sheet 70 is disposed between the metal plate 60 and the housing 10. Specifically, the thermally conductive sheet 70 is interposed between the lower housing 12 of the housing 10 and the metal plate 60. The thermally conductive sheet 70 is sandwiched by the lower housing 12 and the metal plate 60. Figure 5 ​As shown, the lower case 12 of the case 10 has a bottom plate portion 12c. The bottom plate portion 12c has a first portion that is a portion overlapping the heat conducting sheet 70 and a second portion that is a portion not overlapping the heat conducting sheet 70. The thickness of the first portion of the bottom plate portion 12c overlapping the heat conducting sheet 70 is thinner than the thickness of the second portion of the bottom plate portion 12c not overlapping the heat conducting sheet 70. As an example, the thickness of the first portion of the bottom plate portion 12c overlapping the heat conducting sheet 70 is 0.7 mm, and the thickness of the second portion of the bottom plate portion 12c not overlapping the heat conducting sheet 70 is 1.5 mm.

[0085] Thus, by making the thickness of the first portion of the bottom plate portion 12c overlapping the heat conducting sheet 70 thinner than the thickness of the second portion of the bottom plate portion 12c not overlapping the heat conducting sheet 70, it is possible to ensure insulation using both the case 10 and the heat conducting sheet 70, and to improve the heat dissipation of the battery cutoff unit 1.

[0086] As described above, the battery cutoff unit 1 of the present embodiment has: the case 10 made of resin, which has insulation; the relay 20 disposed in the case 10; the bus bar 30 connected to the terminal 21 of the relay 20 and fixed to the case 10 by insert molding; the metal plate 60; and the heat conducting sheet 70 disposed between the case 10 and the metal plate 60.

[0087] Thus, in the battery cutoff unit 1 of the present embodiment, since the bus bar 30 is fixed to the case 10 having insulation by insert molding, it is possible to easily ensure the insulation of the battery cutoff unit 1 with respect to the bus bar 30 through which a large current flows. Also, since the relay 20 is connected to the bus bar 30 fixed by insert molding, it is possible to ensure the mechanical connection strength of the relay 20 to the bus bar 30. Also, since the heat conducting sheet 70 is interposed between the case 10 in which the bus bar 30 (relay bus bar 30a) is fixed by insert molding and the metal plate 60, it is possible to efficiently conduct the heat conducted to the bus bar 30 (relay bus bar 30a) and the heat generated by the bus bar 30 to the metal plate 60 via the heat conducting sheet 70. For example, as shown by the arrow, 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 of the relay bus bar 30a to the first plate portion 31, and further conducted to the metal plate 60 via the heat conducting sheet 70. Thus, it is possible to efficiently dissipate the heat of the bus bar 30 (relay bus bar 30a). Figure 5

[0088] Thus, according to the battery cutoff unit 1 of the present embodiment, it is possible to balance the connection strength, the heat dissipation, and the insulation of the relay 20 and the bus bar 30.

[0089] ​In particular, in the battery cutoff unit 1 of the present embodiment, the heat conducting sheet 70 is in contact with the case 10 and the metal plate 60, respectively.

[0090] According to this structure, the heat conducted to the bus bar 30 (relay bus bar 30a) and the heat generated by the bus bar 30 can be more efficiently conducted to the metal plate 60 via the heat conducting sheet 70. Thus, the heat dissipation of the battery cutoff unit 1 can be further improved.

[0091] In addition, in the battery cutoff unit 1 of the present embodiment, the heat conducting sheet 70 is composed of a resin material having insulating properties.

[0092] According to this structure, between the bus bar 30 (relay bus bar 30a) and the metal plate 60, not only the case 10 having insulating properties but also the heat conducting sheet 70 having insulating properties is interposed as an insulating member, and thus, compared to the case where the heat conducting sheet 70 is composed of an electrically conductive material, the insulating properties of the battery cutoff unit 1 can be further ensured.

[0093] Further, a structure in which the heat conducting sheet 70 and the metal plate 60 are embedded inside the case 10 (lower case 12) is also considered, but in the case of this structure, the following problems arise.

[0094] The first problem is that, in the insert molding, the heat conducting sheet 70 can only be disposed around the bus bar 30 (relay bus bar 30a), and thus the shape of the heat conducting sheet 70 is limited, and the heat dissipation of the battery cutoff unit 1 is degraded.

[0095] The second problem is that, in the case where the heat conducting sheet 70 is pasted to the metal plate 60 and insert molding is performed, the heat resistance temperature of the heat conducting sheet 70 is (about 130 degrees) lower than the temperature of the case 10 (lower case 12) at the time of insert molding (the resin temperature is about 300 degrees), and thus the heat conducting sheet 70 deteriorates.

[0096] On the contrary, in the battery cutoff unit 1 of the present embodiment, the heat conducting sheet 70 is externally provided to the case 10 (lower case 12), and thus the shapes of the heat conducting sheet 70 and the metal plate 60 can be freely set. In addition, in the battery cutoff unit 1 of the present embodiment, the heat conducting sheet 70 and the metal plate 60 are not embedded inside the case 10 (lower case 12), but are directly mounted (externally provided) below the case 10. In this way, according to the battery cutoff unit 1 of the present embodiment, the above-described first problem and second problem do not arise, and in addition, by making both the heat conducting sheet 70 and the case 10 have insulating properties, the miniaturization of the battery cutoff unit 1 can also be achieved.

[0097] Further, in the battery cutoff unit 1 of the present embodiment, the metal plate 60 is in an electrically floating state.

[0098] According to this structure, it is possible to further ensure the insulation of the battery cutoff unit 1.

[0099] In addition, in the battery cutoff unit 1 of the present embodiment, the metal plate 60 is an aluminum plate made of a metal material in which aluminum is the main component.

[0100] According to this structure, it is possible to efficiently conduct the heat of the bus bar 30 (relay bus bar 30a) to the metal plate 60 via the heat conducting sheet 70, and thus it is possible to further improve the heat dissipation of the battery cutoff unit 1.

[0101] In addition, in the battery cutoff unit 1 of the present embodiment, the metal plate 60 is a bottom plate of the battery cutoff unit 1, and the surface of the side of the metal plate 60 opposite to the side of the heat conducting sheet 70 is exposed.

[0102] According to this structure, it is possible to efficiently dissipate the heat of the bus bar 30 (relay bus bar 30a) conducted to the metal plate 60 to the atmosphere. Thus, it is possible to further improve the heat dissipation of the battery cutoff unit 1.

[0103] In addition, in the battery cutoff unit 1 of the present embodiment, the bottom plate portion 12c in the housing 10 has a first portion which is a portion overlapping the heat conducting sheet 70 and a second portion which is a portion not overlapping the heat conducting sheet 70, and the thickness of the first portion is thinner than the thickness of the second portion.

[0104] The resin material constituting the housing 10 has a lower thermal conductivity than the metal material. Thus, by making the thickness of the first portion in the bottom plate portion 12c of the housing 10 overlapping the heat conducting sheet 70 thin, it is possible to efficiently conduct the heat of the bus bar 30 (relay bus bar 30a) to the heat conducting sheet 70. In addition, by making the thickness of the second portion in the bottom plate portion 12c of the housing 10 not overlapping the heat conducting sheet 70 thick, it is possible to ensure the mechanical strength of the housing 10 fixing the bus bar 30. Thus, it is possible to further balance the connection strength of the relay 20 and the bus bar 30, the heat dissipation, and the insulation.

[0105] Next, the manufacturing method of the battery cutoff unit 1 of the present embodiment will be described with reference to FIG. 10. Figure 6 The manufacturing method of the battery cutoff unit 1 of the present embodiment will be described. Figure 6 is a view for explaining the manufacturing method of the battery cutoff unit 1 of the embodiment. Figure 6 In (a) to (d) of FIG. 10, the left drawing is a side view and the right drawing is a perspective view. In addition, in Figure 6 In FIG. 10, only the structure of a part of the components constituting the battery cutoff unit 1 is shown. For example, with respect to the relay 20, only one of the two relays 20 is illustrated, and in addition, with respect to the bus bar 30, only the relay bus bar 30a is illustrated.

[0106] As described above, according to the battery cutoff unit 1 of the present embodiment, it is possible to efficiently conduct the heat of the bus bar 30 (relay bus bar 30a) to the metal plate 60 via the heat conducting sheet 70, and thus it is possible to further improve the heat dissipation of the battery cutoff unit 1. Figure 6As shown in (a), first, the relay 20 is placed in the housing 10 to which the bus bar 30 is fixed. Specifically, the relay 20 is placed in the lower housing 12 to which multiple bus bars 30, including the relay bus bar 30a, are fixed by insert molding. At this time, the relay frame 22 of the relay 20 is placed in the relay storage portion 12a of the lower housing 12 so that the terminals 21 of the relay 20 are aligned with the insertion holes 32a of the relay bus bar 30a.

[0107] Then, if Figure 6 As shown in (b), the relay cover 40 is placed on the relay 20 arranged in the housing 10. Specifically, the relay cover 40 is placed on the support portion 12b of the lower housing 12 so as to cover the relay frame 22 of the relay 20 arranged in the lower housing 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 located above the support portion 12b of the lower housing 12. When the relay cover 40 is placed on the support portion 12b, the relay cover 40 and the relay frame 22 of the relay 20 may or may not be in contact.

[0108] Next, if Figure 6 As shown in (c), the relay cover 40 is fixed to the housing 10 while being pressed toward the housing 10. Specifically, the attachment portion 40a of the relay cover 40 is joined to the support portion 12b of the lower housing 12 while the relay cover 40 is pressed downward.

[0109] For example, a pressing member (not shown) is placed on the relay cover 40, and a press is used to press the pressing member against the relay cover 40. This pressurizes the relay cover 40 while simultaneously joining the mounting portion 40a of the relay cover 40 to 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, for example, by ultrasonic welding, heat welding, or laser welding. Specifically, ultrasonic vibrations, heat, or laser irradiation are applied to the mounting portion 40a of the relay cover 40, causing the resin forming the relay cover 40 and the resin forming the lower case 12 to melt, thereby joining the mounting portion 40a of the relay cover 40 to the support portion 12b of the lower case 12.

[0110] At this time, when the relay cover 40 is placed on the support portion 12b ( Figure 6 In step (b), even if the relay cover 40 is not in contact with the relay frame 22 of the relay 20, by applying pressure to the relay cover 40 while joining the relay cover 40 to the support portion 12b of the lower shell 12, the relay cover 40 comes into contact with the relay frame 22 and the relay frame 22 is pressed against the lower shell 12.

[0111] Thus, by joining the relay cover 40 to the lower case 12 while applying pressure to the relay cover 40, the relay 20 can be held in the lower case 12 while the relay cover 40 is pressing the relay 20 against the lower case 12. Figure 6 In step (a), the relay 20 is tilted relative to the lower housing 12. By applying pressure to the relay cover 40 while joining the relay cover 40 to the lower housing 12, the relay cover 40 can be flexibly joined to the lower housing 12. Therefore, the relay 20 can be held relative to the lower housing 12 by the relay cover 40 without applying stress to the relay 20. In this way, the relay 20 can be stably fixed to the lower housing 12 without directly fixing the relay 20 to the lower housing 12.

[0112] Then, if Figure 6 As shown in (d), after the relay cover 40 is fixed to the housing 10, the terminal 21 of the relay 20 is fixed to the bus bar 30 using the screw 50. Specifically, the screw 50 is inserted through the insertion hole 32a of the relay bus bar 30a, and the screw 50 is screwed into the terminal 21 of the relay 20. In this way, the relay bus bar 30a and the relay 20 can be electrically and mechanically fixed. 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. Therefore, even after the relay 20 is covered with the relay cover 40, the relay 20 and the relay bus bar 30a can be easily fixed using the screw 50.

[0113] Here, use Figure 7 The features of the method for manufacturing the battery disconnect unit 1 of this embodiment will be described in comparison with a battery disconnect unit 1X of a comparative example. Figure 7 It is a diagram showing the structure of a battery disconnect unit 1X of a comparative example.

[0114] like Figure 7 As shown, the battery disconnect unit 1X includes a resin case 10X, and a relay 20X and a bus bar 30X housed in the case 10X.

[0115] exist Figure 7In the battery cut-off unit IX shown, the relay 20X is fixed to the case 10X. In this case, a bolt is inserted as a screw 51X through a through-hole of a fixing-use mounting portion (collar) provided on a side surface of a relay frame 22X of the relay 20X, and the screw 51X is screwed into a nut 35X embedded in the case 10X. Thus, the relay frame 22X of the relay 20X can be fixed to the case 10X. After the relay 20X is fixed to the case 10X, a bus bar 30X as a relay bus bar 30a is threadedly fastened to a terminal 21X of the relay 20X by a screw 52X, and to the case 10X by a screw 53X, whereby the relay 20X can be electrically and mechanically connected to the relay bus bar 30a, and the relay bus bar 30a can be fixed to the case 10X. In addition, in the battery cut-off unit IX shown in FIG. 1, the case 10X is made of resin, and the case 10X is formed by injection molding. Therefore, the case 10X is formed in a shape in which the case 10X is integrally formed with the relay 20X and the bus bar 30X as the relay bus bar 30a. Figure 7 In the battery cut-off unit IX shown in FIG. 1, the case 10X is made of resin, and the case 10X is formed by injection molding. Therefore, the case 10X is formed in a shape in which the case 10X is integrally formed with the relay 20X and the bus bar 30X as the relay bus bar 30a.

[0116] In the battery cut-off unit IX shown in FIG. 1, the case 10X is made of resin, and the case 10X is formed by injection molding. Therefore, the case 10X is formed in a shape in which the case 10X is integrally formed with the relay 20X and the bus bar 30X as the relay bus bar 30a. Figure 7 In the battery cut-off unit IX shown in FIG. 1, the case 10X is made of resin, and the case 10X is formed by injection molding. Therefore, the case 10X is formed in a shape in which the case 10X is integrally formed with the relay 20X and the bus bar 30X as the relay bus bar 30a. Figure 7 As shown in FIG. 1, the case 10X sometimes deforms by being unexpectedly twisted or tilted. In this case, when the relay 20X is arranged at a portion of the case 10X that is deformed, the relay 20X is fixed to the case 10X in a tilted state. In addition, even if the case 10X is not deformed, the relay 20X is tilted at the time of assembly, and the relay 20X is sometimes fixed to the case 10X in a tilted state. In this way, in the battery cut-off unit IX of the related art, assembly failure of the relay 20X sometimes occurs.

[0117] In addition, when assembly failure of the relay 20X occurs, the bus bar 30X (relay bus bar 30a) connected to the relay 20X is threadedly fastened to the terminal 21X of the relay 20X or fixed to the case 10X in a tilted state. Moreover, as a result of the relay bus bar 30a being tilted, the upper bus bar 30b that is commonly fastened to the relay bus bar 30a is also connected in a tilted state with respect to the relay bus bar 30a. In this way, in the battery cut-off unit IX of the related art, assembly failure of the bus bar 30X (relay bus bar 30a) sometimes occurs.

[0118] When such assembly failure of the relay bus bar 30a occurs, the relay bus bar 30a does not make surface contact with the terminal 21X of the relay 20X and / or the upper side bus bar 30b. That is, when assembly failure of the relay bus bar 30a occurs and the relay bus bar 30a is tilted, the relay bus bar 30a is connected to the terminal 21X of the relay 20X in a line contact or point contact manner, or the relay bus bar 30a is connected to the upper side bus bar 30b in a line contact or point contact manner. Therefore, although conduction, the resistance value at the connection portion of the relay bus bar 30a to the terminal 21X of the relay 20X and / or the upper side bus bar 30b increases, the connection portion becomes a heat generation source, and in addition, a gap is 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 side bus bar 30b in the connection portion of the relay bus bar 30a to the terminal 21X of the relay 20X and / or the upper side bus bar 30b, and corrosion at the connection portion is likely to accelerate.

[0119] In particular, if the thickness of the bus bar 30X (relay bus bar 30a) composed of copper is 2 mm or less, the relay bus bar 30a is flexed and forcibly deformed by the tightening force when the relay bus bar 30a is threadedly fastened by the screws 51X and 52X, and as a result, the bus bar 30X sometimes makes surface contact with the terminal 21X of the relay 20X and / or the upper side bus bar 30b, but when the thickness of the bus bar 30X (relay bus bar 30a) composed of copper exceeds 2 mm (for example, 3 mm or more), the bus bar 30X does not deform due to the tightening force of the screws, and as shown in FIG. 6, assembly failure of the relay bus bar 30a remains. Figure 7 In a pure electric vehicle, a large current flows in the bus bar 30X compared to a hybrid electric vehicle, and therefore, instead of using a thin plate having a thickness of 2 mm or less for the bus bar 30X, a thick plate having a thickness of 3 mm or more is used for the bus bar 30X, and therefore, assembly failure of the bus bar 30X (relay bus bar 30a) is likely to occur.

[0120] Furthermore, when assembly failure of the relay bus bar 30a occurs and the relay bus bar 30a is connected to the terminal 21X of the relay 20X in a tilted state, not only the above-mentioned problems of heat generation and corrosion occur, but also a problem that stress and strain occur in the relay bus bar 30a and / or the terminal 21X of the relay 20X occurs. When stress and strain occur in the relay bus bar 30a and / or the terminal 21X of the relay 20X, the long-term reliability of the battery cut-off unit 1X decreases.

[0121] Thus, in the above-described embodiment, the bus bar 30X (relay bus bar 30a) composed of copper is used, and the thickness of the bus bar 30X (relay bus bar 30a) is set to 3 mm or more, and therefore, the bus bar 30X (relay bus bar 30a) is not deformed due to the tightening force of the screws, and assembly failure of the relay bus bar 30a does not occur. Figure 7In the structure of the battery cutoff unit 1X shown, when the relay 20X and the bus bar 30X are fixed to the case 10X, the relay 20X and the bus bar 30X are sometimes fixed obliquely or the like, and assembly failure of the relay 20X and the bus bar 30X occurs.

[0122] In contrast, in the manufacturing method of the battery cutoff unit 1 of the present embodiment, instead of fastening the relay 20X and the bus bar 30X after the relay 20X is fixed to the case 10X as in the battery cutoff unit 1X shown, Figure 7 Figure 6 as shown, the relay 20 is disposed on the case 10 to which the bus bar 30 is fixed in advance, and the relay 20 is held to the case 10 by the relay cover 40, and then the bus bar 30 and the relay 20 are fastened by the screw 50. Therefore, in the battery cutoff unit 1 of the present embodiment, unlike the battery cutoff unit 1X shown, Figure 7

[0123] assembly failure of the relay 20 and the bus bar 30 does not occur.

[0124] According to this structure, as described above, the bus bar 30 (relay bus bar 30a) and the terminal 21 of the relay 20 can be fastened by the screw 50 after the relay 20 is disposed on the case 10 to which the bus bar 30 is fixed in advance, and the relay 20 is held to the case 10 by the relay cover 40. Thus, the relay 20 can be held to the case 10 without wobbling, and the relay 20 and the bus bar 30 (relay bus bar 30a) can be fastened by the screw 50 without applying pressure 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 assembly failure of the relay 20 and the bus bar 30. Therefore, the bus bar 30 (relay bus bar 30a) is in surface contact with the terminal 21 of the relay 20, and thus increase in connection resistance between the bus bar 30 (relay bus bar 30a) and the terminal 21 of the relay 20, which causes heat generation or accelerated corrosion due to a gap, can be suppressed. In addition, since assembly failure of the relay 20 and the bus bar 30 does not occur, the relay 20 can be held to the case 10 without applying pressure to the relay 20 and the bus bar 30. Thus, stress and strain in the bus bar 30 (relay bus bar 30a) and the terminal 21 of the relay 20 can also be suppressed. Therefore, the battery cutoff unit 1 with excellent long-term reliability can be realized.

[0125] ​​Further, in the battery cutoff unit 1 of 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. That is, the terminal 21 of the relay 20 is exposed from the relay cover 40 in the lateral direction.

[0126] Thus, even after the relay 20 is covered by the relay cover 40, the relay 20 and the relay bus bar 30a can be easily fixed by the screw 50.

[0127] Further, 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.

[0128] According to this structure, the bus bar 30 (relay bus bar 30a) can be fixed to the case 10 integrally in advance, and thus assembly failure of the bus bar 30 can be eliminated. Further, in the case where a nut for the screw to be inserted when the bus bar 30 is fixed to the case 10 by post-installation is fixed to the case 10 by insert molding, the nut and the relay bus bar 30a can be simultaneously fixed to the case 10 by insert molding. That is, the relay bus bar 30a can be fixed to the case 10 without additionally adding an insert molding process.

[0129] Further, since the bus bar 30 (relay bus bar 30a) fixed to the case 10 by insert molding does not generate stress and strain, even in the case where the relay bus bar 30a fixed by insert molding is fastened and connected to another bus bar 30 such as the upper bus bar by a screw, the relay bus bar 30a can be brought into surface contact with the other bus bar 30. That is, the relay bus bar 30a can be connected to the other bus bar 30 without a gap at the connecting portion of the relay bus bar 30a and the other bus bar 30.

[0130] Further, in the battery cutoff unit 1 of the present embodiment, the relay bus bar 30a as the bus bar 30 connected to the relay 20 has a first plate portion 31 and a second plate portion 32 erected on the first plate portion 31. Further, a part or the whole of the first plate portion 31 is embedded in the case 10, and the second plate portion 32 is fixed to the terminal 21 of the relay 20 by the screw 50.

[0131] According to this structure, the second plate portion 32 of the bus bar 30 is erected from the first plate portion 31 in a manner exposed from the case 10, and thus 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 by the screw 50.

[0132] Further, in the battery cutoff unit 1 of the present embodiment, the relay 20 has a relay housing 22, and the terminal 21 is provided to a side surface of the relay housing 22. That is, the relay 20 is arranged so that the terminal 21 is in a horizontal direction.

[0133] According to this structure, the terminal 21 of the relay 20 can be easily opposed to the second plate portion 32 erected from the first plate portion 31 of the bus bar 30 embedded in the case 10, and thus the bus bar 30 and the terminal 21 of the relay 20 can be easily fastened by the screw 50.

[0134] Further, in the battery cutoff unit 1 of the present embodiment, the thickness of the bus bar 30 (relay bus bar 30a) is 3 mm or more. That is, the thickness of the bus bar 30 is a thickness that does not flex even if fastened by a screw.

[0135] In a case where the bus bar 30 flexes due to the fastening force of the screw, when the bus bar 30 and the terminal 21 of the relay 20 are fixed by the screw, the bus bar 30 flexes, and thus the bus bar 30 and the terminal 21 of the relay 20 can be fixed in surface contact. However, in a case where the bus bar 30 does not flex due to the fastening force of the screw, assembly failure of the relay 20 and the bus bar 30 occurs, and the bus bar 30 and the terminal 21 of the relay 20 cannot be fixed in surface contact. In contrast, in the present embodiment, after the case 10 in which the bus bar 30 is preliminarily fixed is arranged with the relay 20, and the relay 20 is fixed to the case 10 by the relay cover 40, the bus bar 30 (relay bus bar 30a) and the relay 20 are fixed by the screw 50. Thus, even in a case where a bus bar 30 having a thickness of 3 mm or more (i.e., a bus bar 30 that does not flex due to the fastening force of the screw) is used in association with large current, assembly failure of the relay 20 and the bus bar 30 does not occur, and the relay 20 and the bus bar 30 can be fixed to the case 10. Therefore, the battery cutoff unit 1 of the present embodiment is suitable for a pure electric vehicle that has a larger current than a hybrid electric vehicle.

[0136] (Modified Example)

[0137] The technology of the present disclosure has been described based on the embodiments above, but the present disclosure is not limited to the above-described embodiments.

[0138] For example, in the above-described embodiments, the terminal 21 of the relay 20 is provided to a side surface of the relay housing 22, but is not limited thereto, and can be provided to an upper surface of the relay housing 22. That is, the relay 20 can not be arranged so that the terminal 21 is in a horizontal direction, but can be arranged so that the terminal 21 is upward.

[0139] Further, in the above-described embodiment, the relay cover 40 and the housing 10 are fixed by welding, but are not limited thereto. For example, the relay cover 40 and the housing 10 can also be fixed by screws or rivets, or the like.

[0140] Further, in the above-described embodiment, after the relay 20 is pressed by the relay cover 40 and held to the housing 10, the terminal 21 of the relay 20 is fastened to the bus bar 30 by the screw 50, but is not limited thereto. For example, after the relay 20 disposed to the housing 10 in which the bus bar 30 is fixed is fastened to the bus bar 30 by the screw 50, the relay 20 can be pressed by the relay cover 40 and held to the housing 10 by engaging the relay cover 40 to the housing 10.

[0141] Further, in the above-described embodiment, the battery cutoff unit 1 is used for an electric automobile, but is not limited thereto. For example, the battery cutoff unit 1 can also be applied to an electric product such as a home electric appliance, or the like.

[0142] Further, the technology of the present disclosure is applied to the battery cutoff unit 1, but is not limited thereto. The technology of the present disclosure can also be used for an electric connection box other than the battery cutoff unit 1. For example, the technology of the present disclosure can also be used for a charging unit or the like connected to a battery. Further, the technology of the present disclosure can also be used for an electric connection box other than a unit connected to a battery, as long as the electric connection box has a relay.

[0143] Further, modes obtained by applying various modifications to the above-described embodiment, which are thought of by those skilled in the art, and modes realized by arbitrarily combining the constituent elements and functions in the embodiments within a range not departing from the gist of the present disclosure are also included in the present disclosure. Further, a scheme in which two or more claims are arbitrarily combined from among the plurality of claims recited in the claims at the time of filing of the present application within a range not technically contradictory is also included in the present disclosure. For example, in a case where a multiple dependent claim or a multiple multiple dependent claim is set in a manner in which all of the parent claims recited in the claims at the time of filing of the present application are cited within a range not technically contradictory, the combination of all of the claims included in the multiple dependent claim or the multiple multiple dependent claim is also included in the present disclosure.

[0144] Industrial Applicability

[0145] The technology of the present disclosure can be widely used for various products such as automobiles or electric products, or the like.

[0146] Explanation of Reference Signs

[0147] 1 Battery cutoff unit

[0148] 2 Battery

[0149] 3 Inverter

[0150] 10 housing

[0151] 11 upper housing

[0152] 12 lower housing

[0153] 12a relay housing portion

[0154] 12b support portion

[0155] 12c bottom plate portion

[0156] 20 relay

[0157] 21 terminal

[0158] 22 relay frame

[0159] 22a insulating plate

[0160] 30 bus bar (metallic conductor)

[0161] 31 first plate portion

[0162] 32 second plate portion

[0163] 32a insertion hole

[0164] 30a relay bus bar

[0165] 40 relay cover

[0166] 40a mounting portion

[0167] 50 screw

[0168] 60 metal plate

[0169] 70 heat conducting sheet

[0170] 100 drive system

Claims

1. An electrical connection box, wherein: have: The resin shell has insulating properties; a relay, disposed in the housing; a bus bar connected to the terminals of the relay and fixed to the housing by insert molding; Metal sheets; and The heat conducting sheet is arranged between the shell and the metal plate.

2. The electrical connection box according to claim 1, wherein The heat conducting sheet is connected to the housing and the metal plate respectively.

3. The electrical connection box according to claim 1 or 2, wherein: The electrical connection box further includes a relay cover covering the relay. The relay cover presses the relay against the housing.

4. The electrical connection box according to claim 3, wherein: The terminals of the relay are fixed to the bus bar by screws.

5. The electrical connection box according to claim 4, wherein: In the insertion direction of the screw, the terminals of the relay are not covered by the relay cover.

6. The electrical connection box according to any one of claims 1 to 5, wherein: The thermally conductive sheet is made of an insulating resin material.

7. The electrical connection box according to claim 6, wherein: The metal plate is in an electrically floating state.

8. The electrical connection box according to claim 7, wherein: The metal plate is an aluminum plate made of a metal material mainly composed of aluminum.

9. The electrical connection box according to any one of claims 1 to 8, wherein: The metal plate is the bottom plate of the electrical connection box, The surface opposite to the thermally conductive sheet is exposed.

10. The electrical connection box according to any one of claims 1 to 9, wherein: The bottom plate portion of the housing has a first portion overlapping with the heat conducting sheet and a second portion not overlapping with the heat conducting sheet. The thickness of the first portion is thinner than the thickness of the second portion.

11. The electrical connection box according to any one of claims 1 to 10, wherein: A plating film is formed on the surface of the bus bar.

12. The electrical connection box according to any one of claims 1 to 11, wherein: The busbar is formed of a metal plate or a cast metal conductor.

13. A method for manufacturing an electrical connection box, wherein: include: The process of arranging a relay in a housing to which a bus bar is fixed; a step of disposing a relay cover on the relay disposed on the housing; a step of fixing the relay cover to the housing while pressing the relay cover toward the housing; and After the relay cover is fixed to the housing, the terminal of the relay is fixed to the bus bar with screws.

14. The method for manufacturing an electrical junction box according to claim 13, wherein: The relay cover and the housing are joined together by ultrasonic waves or welding.

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