Electrical junction box

Abstract

A battery shut-off unit (1), which is an example of this electrical junction box, comprises an electrical component (10) and a die-cast conductor block (20). The conductor block (20) has a heat conduction part (21) and a heat capacity part (22) having a length greater than the thickness of the heat conduction part (21) in the thickness direction of the heat conduction part (21). One among the heat conduction part (21) and the heat capacity part (22) is provided with a fastening part (23) that is a portion connected to a terminal of the electrical component (10) by a fastening member (50).

Description

Electrical junction box

[0001] The present disclosure relates to an electrical junction box, such as a battery disconnect unit.

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

[0003] A known example of this type of power connection box is a battery disconnect unit (BDU) that includes electrical components such as a relay and a fuse. The BDU cuts off or supplies power output from a battery.

[0004] One known battery cutoff unit of this type includes a relay, a bus bar connected to the terminals of the relay, and a heat sink fixed to the bus bar (see Patent Document 1). This allows heat generated by the relay to be dissipated to the heat sink via the bus bar.

[0005] International Publication No. 2018 / 225470

[0006] However, a bus bar made of a metal plate does not have sufficient thermal capacity, and simply connecting the relay to the heat sink with a bus bar is not enough to dissipate the heat generated by the relay. In particular, when the temperature of the relay rises suddenly, the heat generated by the relay cannot be quickly conducted to the bus bar. As a result, the heat can cause malfunctions in the relay.

[0007] The present disclosure has been made to solve such problems, and aims to provide an electrical junction box that can sufficiently dissipate heat generated by electrical components such as relays.

[0008] In order to achieve the above-mentioned object, one aspect of the electrical connection box according to the present disclosure comprises an electrical component and a die-cast conductor block, the conductor block having a heat conduction portion and a heat capacity portion having a length in the thickness direction of the heat conduction portion that is greater than the thickness of the heat conduction portion, and one of the heat conduction portion and the heat capacity portion is provided with a fastening portion that is connected to a terminal of the electrical component by a fastening member.

[0009] According to the present disclosure, heat generated by an electrical component such as a relay can be sufficiently dissipated.

[0010] FIG. 1 is a block diagram of a drive system according to an embodiment. FIG. 2 is a perspective view of a battery cutoff unit according to an embodiment. FIG. 3 is an exploded perspective view of the battery cutoff unit according to an embodiment. FIG. 4 is a cross-sectional view of the battery cutoff unit installed on a heat dissipation member. FIG. 5 is a perspective view of a first module in a battery cutoff unit according to an embodiment, as viewed from above. FIG. 6 is a perspective view of the first module in a battery cutoff unit according to an embodiment, as viewed from below. FIG. 7 is an exploded perspective view of the first module in a battery cutoff unit according to an embodiment. FIG. 8 is a cross-sectional view of the first module in a battery cutoff unit according to an embodiment. FIG. 9 is a perspective view of the first module in a battery cutoff unit according to an embodiment, with an insulating sheet separated. FIG. 10 is a perspective view showing two of four conductor blocks in a first module in a battery cutoff unit according to an embodiment. FIG. 11 is a cross-sectional perspective view of a second module in a battery cutoff unit according to an embodiment.

[0011] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that each of the embodiments described below represents a specific example of the present disclosure. Therefore, the numerical values, components, arrangement positions and connection forms of the components, etc. 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 not recited in independent claims will be described as optional components.

[0012] Note that each figure is a schematic diagram and is not necessarily a precise illustration. Furthermore, in each figure, substantially the same configuration is assigned the same reference numeral, and duplicate explanations are omitted or simplified. Furthermore, in this specification, the terms "up" and "down" do not necessarily refer to the upward direction (vertically upward) and downward direction (vertically downward) in absolute spatial recognition.

[0013] 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.

[0014] As shown in FIG. 1 , the drive system 100 includes a battery cutoff unit 1 , a battery 2 , and an inverter 3 .

[0015] The battery cutoff unit 1 is an example of an electrical connection box for connecting the battery 2 to various electrical 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.

[0016] 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 either 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. Alternatively, the battery cutoff unit 1 may be equipped with a rapid charging circuit.

[0017] 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 to this.

[0018] The inverter 3 is an AC / DC converter that converts 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.

[0019] The drive system 100 configured as described above is installed in an electric vehicle such as a hybrid electric vehicle or a pure electric vehicle. That is, the battery cutoff unit 1 is installed in an electric vehicle (EV) together with the battery 2. For example, the battery cutoff unit 1 is installed in a battery electric vehicle (BEV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), or a fuel cell electric vehicle (FCEV). In this case, DC power output from the battery 2 is supplied to an inverter 3 via the battery cutoff unit 1 as drive energy for running the electric vehicle and 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.

[0020] Next, the overall structure of the battery cutoff unit 1 according to the embodiment will be described with reference to Figures 2 to 4. Figure 2 is a perspective view of the battery cutoff unit 1 according to the embodiment. Figure 3 is an exploded perspective view of the battery cutoff unit 1 according to the embodiment. The case 30 is omitted from Figure 3. Figure 4 is a cross-sectional view of the battery cutoff unit 1 installed on the heat dissipation member 5.

[0021] 2 to 4, the battery cutoff unit 1 is composed of three modules: a first module 1a, a second module 1b, and a third module 1c. The first module 1a, the second module 1b, and the third module 1c are electrically connected to each other and are configured to be physically separable.

[0022] The first module 1a is a P-side (positive side) module, the second module 1b is an N-side (negative side) module, and the third module 1c is an intermediate module disposed between the first module 1a and the second module 1b.

[0023] The battery cutoff unit 1 includes a plurality of electrical components 10, a plurality of conductor blocks 20, a case 30, and an insulating sheet 40.

[0024] Specifically, each of the first module 1 a, the second module 1 b, and the third module 1 c includes a plurality of electrical components 10, a plurality of conductor blocks 20, a case 30, and an insulating sheet 40.

[0025] The plurality of electrical components 10 include relays 11, fuses 12, and shunt resistors 13. Specifically, the first module 1a has two relays 11 and one fuse 12 as the plurality of electrical components 10. The second module 1b has two relays 11, one fuse 12, and one shunt resistor 13 as the plurality of electrical components 10. The third module 1c has four relays 11 and one shunt resistor 13 as the plurality of electrical components 10.

[0026] The plurality of relays 11 in each of the first module 1a, the second module 1b, and the third module 1c 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. For example, the first module 1a and the second module 1b are provided with two relays 11, a first P-side main relay and a second N-side main relay.

[0027] A pre-charge relay may be included among the plurality of relays 11. Furthermore, if the battery cutoff unit 1 has a quick charge circuit, the plurality of relays 11 may include a first quick charge relay on the positive side corresponding to the electrode on the positive side of the battery 2, and a second quick charge relay on the negative side corresponding to the electrode on the negative side of the battery 2.

[0028] The relay 11 has a function of turning on and off current flow. Specifically, in FIG. 1 , the relay 11 has a function of switching between interrupting and supplying DC power supplied from the battery 2 to the battery cutoff unit 1 to the inverter 3. For example, the relay 11 performs conduction and opening (insulation) of the circuit constituting the battery cutoff unit 1 in response to a control signal (e.g., a 12 V signal) from the automobile side. The relay 11 is a power device, and generates heat when current is applied. In other words, the relay 11 is a heat-generating component.

[0029] In this embodiment, the relay 11 is a mechanical relay (contact relay). Note that other types of relays (such as a semiconductor relay or a contactless relay) can also be used as the relay 11, but in order to reliably switch between interrupting and supplying 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 preferable that the relay 11 be a mechanical relay.

[0030] The fuse 12 has a function of interrupting the circuit when an abnormal current occurs. Specifically, the fuse 12 has a function of interrupting the current when an overcurrent flows. The fuse 12 has a pair of terminals and a case. The pair of terminals of the fuse 12 are metal terminals made of a metal material and are provided on the case so as to protrude from the side of the case.

[0031] In this embodiment, fuse 12 is an active type fuse (active fuse) that cuts off a current path in response to a control signal. Specifically, fuse 12 is a pyro-fuse that contains explosives and irreversibly cuts off the current path by the explosives ignited when an external cutoff command signal is received. Note that fuse 12 is not limited to an active type fuse, and may be a passive type fuse. As passive type fuse (passive fuse) 12, a blowout fuse (current fuse) that blows when an overcurrent flows can be used.

[0032] The shunt resistor 13 is a resistor for detecting current and functions as a current sensor. By inserting the shunt resistor 13, the current flowing through the battery cutoff unit 1 can be measured.

[0033] Each of the plurality of conductor blocks 20 is a wiring member through which current flows and a heat-conducting member that conducts heat. Therefore, each conductor block 20 is preferably made of a conductive material with high thermal conductivity and electrical conductivity.

[0034] The plurality of conductor blocks 20 are electrically and mechanically connected to any of the plurality of electrical components 10. Therefore, each conductor block 20 serves as a current path for the current supplied to the electrical component 10. In this embodiment, the plurality of conductor blocks 20 are connected to a relay 11. The plurality of conductor blocks 20 further includes a conductor block 20 to which a fuse 12 is also connected and a conductor block 20 to which a shunt resistor 13 is also connected. It is not necessary for all of the conductor blocks 20 to be connected to the relay 11. In other words, the plurality of conductor blocks 20 may include a conductor block 20 to which no relay 11 is connected. Furthermore, the plurality of conductor blocks 20 may include a conductor block 20 that is not connected to any electrical component 10.

[0035] The conductor block 20 also functions as a heat sink that absorbs heat generated by heat-generating components. Therefore, the conductor block 20 is preferably configured as a thick, block-shaped metal rigid body so as to have a certain level of heat capacity, rather than a thin plate. For example, the conductor block 20 absorbs heat generated by the relay 11.

[0036] A die-cast block body can be used as such a conductor block 20. In other words, the conductor block 20 is not produced by bending a metal plate, but is produced as a single metal block. In this embodiment, the conductor block 20 is made of a material primarily composed of aluminum. Specifically, the conductor block 20 is made of an aluminum alloy or pure aluminum. Therefore, the conductor block 20 is a die-cast aluminum block body. This allows the conductor block 20 to have high thermal conductivity and electrical conductivity, thereby allowing heat generated in the electrical component 10 to be efficiently conducted to the conductor block 20. Furthermore, by using a die-cast conductor block 20, costs can be reduced. As an example, the aluminum material used to produce the conductor block 20 is ADC12.

[0037] The conductor block 20 is coated with a metal film. In this embodiment, a plating film is formed on the surface of the conductor block 20, which is made of aluminum die-cast. The plating film formed on the surface of the conductor block 20 is, for example, a nickel plating film, a tin plating film, a silver plating film, or a zinc plating film. By forming a plating film on the surface of the conductor block 20 in this way, the contact resistance of the conductor block 20 can be reduced.

[0038] Each conductor block 20 conducts (absorbs) heat generated in the electrical component 10 of the heat-generating component to the conductor block 20, and then conducts the heat to other components. Specifically, since the conductor block 20 is connected to the relay 11, the conductor block 20 conducts the heat generated in the relay 11 to the conductor block 20, and then to the insulating sheet 40. The conductor block 20 is in contact with the insulating sheet 40. In this embodiment, all of the conductor blocks 20 are in contact with the insulating sheet 40.

[0039] 2 and 4 is a housing that houses the electrical component 10 and the conductor block 20. In this embodiment, the case 30 is a lower case of the battery disconnecting unit 1, and is open at the top. In this embodiment, the case 30 is an outer casing member that forms the outer casing of the battery disconnecting unit 1. Although not shown, the battery disconnecting unit 1 may also have an upper case that is combined with the lower case 30.

[0040] The case 30 is a resin case made of an insulating resin material, and may be made of, for example, polyphenylene sulfide (PPS), polybutylene terephthalate (PBT), or an alloy of polyphenylene ether (PPE) and nylon, taking into consideration the heat resistance temperature and strength.

[0041] Conductor blocks 20 are fixed to the case 30. The plurality of conductor blocks 20 are fixed to the case 30 in advance by insert molding. That is, the plurality of conductor blocks 20 are insert-molded products in which at least a portion of each is embedded in the case 30 (a resin member). This allows the plurality of conductor blocks 20 and the case 30 to be integrated into a module. Specifically, the conductor blocks 20, each having a surface made of aluminum die-cast metal and coated with a plating film in advance, are integrated with the case 30 by insert molding.

[0042] As shown in Fig. 4, each of the multiple conductor blocks 20 is embedded in the case 30 so that the bottom surface of the conductor block 20 is exposed. In other words, the case 30 is open not only at the top but also at the bottom. Therefore, the resin material that constitutes the case 30 is not formed on the bottom surface of the conductor block 20, and the bottom surface of the conductor block 20 is exposed from the opening in the bottom portion of the case 30. When viewed from above, the case 30 is formed so as to surround the entire multiple conductor blocks 20. Note that some of the multiple conductor blocks 20 may not be embedded in the case 30. In this case, the conductor block 20 is fixed to the case 30 with screws or the like.

[0043] The case 30 includes a first case portion 30a corresponding to the first module 1a, a second case portion 30b corresponding to the second module 1b, and a third case portion 30c corresponding to the third module 1c. The first case portion 30a, the second case portion 30b, and the third case portion 30c are configured to be separable. Each of the first case portion 30a, the second case portion 30b, and the third case portion 30c is a cylinder having a rectangular opening, and its four outer surfaces form four side surfaces of a rectangular parallelepiped. Note that the resin member constituting the case 30 may cover not only the side surfaces of the conductor block 20 but also the top surface of the conductor block 20.

[0044] As shown in Figure 4, a heat dissipation member 5 is installed under the battery disconnecting unit 1. Therefore, the lower surface of the case 30, which faces the heat dissipation member 5, is open. The heat dissipation member 5 is a member that dissipates heat generated in the battery disconnecting unit 1 by diffusing (dissipating) it. Specifically, the heat dissipation member 5 diffuses heat conducted to the conductor block 20. As an example, the heat dissipation member 5 is a water cooler, a heat dissipation plate such as a metal plate (e.g., an aluminum plate or a copper plate), or a heat dissipation member made of a metal block (e.g., an aluminum block or a copper block).

[0045] The plurality of conductor blocks 20 are embedded in the case 30 (resin member) so that the surface facing the heat dissipation member 5 on which the battery cutoff unit 1 is installed is exposed. By arranging an insulating sheet 40 on the surface of the conductor block 20 exposed from the case 30, the conductor block 20 and the insulating sheet 40 can be brought into contact with each other, so that heat conducted to the conductor block 20 can be efficiently conducted to the insulating sheet 40.

[0046] The insulating sheets 40 are arranged to cover the openings in the lower portions of the case 30. Specifically, the insulating sheets 40 are arranged to cover the openings in the lower portions of the first case portion 30a, the second case portion 30b, and the third case portion 30c. In other words, the battery cutoff unit 1 has three insulating sheets 40.

[0047] 4 , each insulating sheet 40 is disposed between the heat dissipation member 5 installed below the battery disconnecting unit 1 and the plurality of conductor blocks 20. This ensures insulation between the conductor blocks 20 and the heat dissipation member 5. In this embodiment, the insulating sheet 40 is in contact not only with the conductor blocks 20 but also with the heat dissipation member 5. Specifically, the insulating sheet 40 is in close contact with the lower surface of the conductor block 20 and the upper surface of the heat dissipation member 5.

[0048] The insulating sheet 40 is a thin insulating member in a sheet shape made of an insulating material. Specifically, the insulating sheet 40 is a resin sheet made of a resin material having insulating properties. As an example, the resin material making up the insulating sheet 40 is a silicone-based or acrylic-based resin material.

[0049] The insulating sheet 40 is preferably an insulating heat-conducting sheet (thermal sheet) made of a material with high thermal conductivity, which allows the heat conducted to the conductor block 20 to be efficiently conducted to the heat dissipation member 5 via the insulating sheet 40. As an example, the thermal conductivity of the insulating sheet 40 is 1 W / m·K or more, but is not limited to this.

[0050] The insulating sheet 40 is preferably made of an elastomer having rubber elasticity, which allows the insulating sheet 40 to be in close contact with the conductor block 20 and the heat dissipation member 5, thereby enabling the heat conducted to the conductor block 20 to be conducted to the heat dissipation member 5 more efficiently via the insulating sheet 40.

[0051] In this embodiment, the insulating sheet 40 has a laminated structure in which a plurality of thermally conductive sheets are stacked. Specifically, the insulating sheet 40 is composed of two thermally conductive sheets. The thickness of each thermally conductive sheet is preferably 2 mm or less.

[0052] Next, the electrical components 10 and the conductor block 20 in the battery disconnecting unit 1 will be described in detail with reference to Figures 5 to 10. In particular, the relay 11 and the conductor block 20 will be mainly described based on the first module 1a in the battery disconnecting unit 1.

[0053] FIG. 5 is a perspective view of the first module 1a as viewed from above, FIG. 6 is a perspective view of the first module 1a as viewed from below, and FIG. 7 is an exploded perspective view of the first module 1a. FIG. 8 is a cross-sectional view of the first module 1a. FIG. 9 is a perspective view of the first module 1a with the insulating sheet 40 separated. FIG. 10 is a perspective view showing two of the four conductor blocks 20 in the first module 1a. Note that the fuse 12 in the first module 1a is omitted from FIGS. 5 to 9. In addition, in FIG. 8, the heat dissipation member 5 on which the battery cutoff unit 1 is installed is indicated by a dashed line.

[0054] 5 to 8, the first module 1a includes a relay 11, which is an electrical component 10, a conductor block 20, a case 30, which is a first case portion 30a, and an insulating sheet 40. The first module 1a includes two relays 11 and four conductor blocks 20.

[0055] As shown in Fig. 8, the relay 11 has a pair of terminals 11a and an insulating relay housing 11b to which the pair of terminals 11a are fixed. The pair of terminals 11a are fixed terminals. The pair of terminals 11a are external connection terminals that are connected to external members. Specifically, each of the pair of terminals 11a is connected to a conductor block 20. The pair of terminals 11a are metal terminals made of a metal material. Note that, although Fig. 8 illustrates the pair of terminals 11a as being connected by a single member, the pair of terminals 11a are electrically separated by an insulating member inserted between the pair of terminals 11a.

[0056] Although not shown, the relay 11 has a movable contact that comes into contact with and separates from one of a pair of terminals 11a, which are fixed terminals. The relay 11 can interrupt or supply current by bringing this movable contact into contact with or separating from the fixed terminal.

[0057] The relay housing 11b is, for example, a resin case made of a resin material. As an example, the relay housing 11b is a rectangular parallelepiped having six faces (top, bottom, and four side faces). The movable contact is housed in the relay housing 11b.

[0058] 8, the relay 11 further includes an insulating plate 11c located between the pair of terminals 11a. The insulating plate 11c is an insulating wall that separates the pair of terminals 11a. Specifically, the insulating plate 11c is a part of the relay housing 11b and is provided in an upright position on the surface of the relay housing 11b on which the terminals 11a are provided.

[0059] As shown in Fig. 8, the relay 11 is placed on the conductor block 20. Specifically, the relay housing 11b of the relay 11 is placed on the conductor block 20. In this case, as shown in Fig. 8, the relay 11 is arranged so that the terminal 11a faces downward. In this case, the insulating sheet 40 is present below the terminal 11a of the relay 11, so that the insulation of the terminal 11a can be strengthened.

[0060] 8, the conductor block 20 is connected to the terminal 11a of the relay 11 by a fastening member 50. In this embodiment, the fastening member 50 is a screw. Specifically, the fastening member 50 is a screw having a screw head 51 and a screw shaft 52. The conductor block 20 and the relay 11 are fixed together by the screw.

[0061] As shown in Figures 7, 8, and 10, each of the multiple conductor blocks 20 has a block-shaped heat conduction portion 21 and a block-shaped heat capacity portion 22. The heat conduction portion 21 and the heat capacity portion 22 have, for example, a rectangular parallelepiped structure, but may also have multiple fins. The heat conduction portion 21 protrudes from a portion of the heat capacity portion 22. Specifically, the heat conduction portion 21 protrudes laterally from the side of the heat capacity portion 22. Conversely, the heat capacity portion 22 protrudes from a portion of the heat conduction portion 21. Specifically, the heat capacity portion 22 protrudes upward from the top of the heat conduction portion 21. In this embodiment, the protruding direction of the heat conduction portion 21 and the protruding direction of the heat capacity portion 22 are perpendicular to each other. Furthermore, the heat conduction portion 21 and the heat capacity portion 22 are integrally configured.

[0062] The heat conducting portion 21 mainly functions to conduct heat generated in the relay 11 to the heat capacity portion 22 or the heat dissipation member 5. Therefore, in the conductor block 20, the heat conducting portion 21 is located closer to the relay 11 than the heat capacity portion 22. Specifically, the heat conducting portion 21 is connected to the terminal 11 a of the relay 11.

[0063] As shown in Fig. 8 , the electric component 10 is placed on the heat conductive portion 21. Specifically, the relay 11 is placed on the heat conductive portion 21. The heat conductive portion 21 is connected to the terminal 11a of the relay 11 by a fastening member 50. Specifically, as shown in Figs. 8 and 9 , the heat conductive portion 21 is provided with a fastening portion 23 that is connected to the terminal 11a of the relay 11.

[0064] 7, 8, and 10, the fastening portion 23 has an insertion hole 23a through which a fastening member 50 is inserted. As shown in Fig. 8, a screw shaft 52 of the fastening member 50, which is a screw, is inserted into the insertion hole 23a. The screw shaft 52 is inserted into the insertion hole 23a and screwed into a screw hole 11a1 provided in the terminal 11a of the relay 11. This allows the heat conduction portion 21 and the terminal 11a of the relay 11 to be fixed by the fastening member 50.

[0065] 8 and 9, the fastening portion 23 is provided with a recess 23b for accommodating the screw head 51 of the fastening member 50, which is a screw. The recess 23b is a counterbore portion for accommodating the screw head 51. The depth of the recess 23b is preferably greater than the height of the screw head 51. This prevents a portion of the screw head 51 from protruding from the recess 23b.

[0066] The heat capacity portion 22 in the conductor block 20 has a certain heat capacity or more, and mainly functions to store heat transferred from the heat conduction portion 21. For this reason, as shown in Figures 8 and 10, the heat capacity portion 22 has a length in the thickness direction of the heat conduction portion 21 that is greater than the thickness of the heat conduction portion 21. Specifically, the volume of the heat capacity portion 22 is greater than the volume of the heat conduction portion 21, and the heat capacity of the heat capacity portion 22 is greater than the heat capacity of the heat conduction portion 21. Conversely, the heat conduction portion 21 has a portion that is thinner than the heat capacity portion 22, and the volume of the heat conduction portion 21 is smaller than the volume of the heat capacity portion 22.

[0067] The thicknesses of the heat conductive portion 21 and the heat capacity portion 22 are thicker than the thickness of the bus bar made of a metal plate (approximately 4 mm at most). As an example, the thickness L1 of the heat conductive portion 21 is preferably 5 mm or more, and preferably 10 mm or more. In this embodiment, the thickness L1 of the heat conductive portion 21 is 15 mm. The length (height) L2 of the heat capacity portion 22 is preferably at least twice the thickness of the heat conductive portion 21, and preferably at least three times the thickness. The length L2 of the heat capacity portion 22 is preferably approximately the same as the height of the relay 11.

[0068] Stud bolts serving as connection pins are provided on the conductive block 20. Specifically, the stud bolts are provided on the upper surface of the heat capacity portion 22.

[0069] 8, in the first module 1a, the conductor block 20 is arranged so that the heat conduction portion 21 is located below the heat capacity portion 22. Therefore, in the conductor block 20 of the first module 1a, the relay 11 is placed on the upper surface of the heat conduction portion 21, and the insulating sheet 40 is in contact with the lower surface of the heat conduction portion 21. Furthermore, in the conductor block 20 of the first module 1a, the heat capacity portion 22 protrudes upward from the heat conduction portion 21.

[0070] In the first module 1a configured as described above, heat generated in the relay 11 is conducted from the terminal 11a to the heat conductive portion 21 of the conductor block 20 and then to the heat dissipation member 5 via the insulating sheet 40. At this time, even if the heat energy generated in the relay 11 is so large that the heat cannot be absorbed by the heat conductive portion 21 alone, the conductor block 20 in this embodiment is provided with a heat capacity portion 22 adjacent to the heat conductive portion 21. Therefore, the heat generated in the relay 11 can be conducted to the heat capacity portion 22 via the heat conductive portion 21 and stored in the heat capacity portion 22. As a result, even if the heat energy generated in the relay 11 is large, the heat generated in the relay 11 can be sufficiently conducted to the conductor block 20. The heat stored in the heat capacity portion 22 is either radiated from the heat capacity portion 22 to the outside of the conductor block 20 (to the atmosphere) or, when the relay 11 no longer generates heat, is conducted to the heat dissipation member 5 via the heat conductive portion 21 and dissipated.

[0071] In the first module 1a, the relay 11 is placed on the conductor block 20 with the terminal 11a facing downward, but this is not limited to this. For example, as shown in Fig. 11, in the second module 1b, the relay 11 is placed on the conductor block 20 with the terminal 11a facing sideways. In this case, the conductor block 20 is arranged so that the heat capacity portion 22 is located below the heat conduction portion 21. Therefore, in the second module 1b, the relay 11 is placed on the upper surface of the heat capacity portion 22 of the conductor block 20, and an insulating sheet 40 (not shown) contacts the lower surface of the heat capacity portion 22.

[0072] In the second module 1b configured in this manner, heat generated in the relay 11 is conducted from the terminal 11a to the heat conduction portion 21 of the conductor block 20, then to the heat capacity portion 22, and then to the heat dissipation member 5 via the insulating sheet 40. At this time, in the second module 1b, the heat capacity portion 22 of the conductor block 20 is in contact with the insulating sheet 40, so the heat generated in the relay 11 is not only conducted from the terminal 11a of the relay 11 to the heat capacity portion 22 via the heat conduction portion 21, but also from the relay housing 11b placed on the heat capacity portion 22 to the heat capacity portion 22, and is then conducted to the heat dissipation member 5 via the insulating sheet 40.

[0073] As described above, the battery disconnecting unit 1 according to this embodiment includes the electrical component 10 and the die-cast conductor block 20. The conductor block 20 has the heat conductive portion 21 and the heat capacity portion 22, which has a length in the thickness direction of the heat conductive portion 21 that is greater than the thickness of the heat conductive portion 21. The heat conductive portion 21 is provided with the fastening portion 23, which is connected to the terminal of the electrical component 10 by the fastening member 50.

[0074] With this configuration, not only can the heat generated in the electrical component 10 be conducted to the heat conduction portion 21 of the conductor block 20, but also, because the conductor block 20 has the heat capacity portion 22, even if the energy of the heat generated in the electrical component 10 is large, the heat can be efficiently drawn into the heat capacity portion 22 via the heat conduction portion 21. This allows the heat generated in the electrical component 10 to be sufficiently dissipated. In this embodiment, the relay 11 is connected to the conductor block 20, so the heat generated in the relay 11 can be sufficiently dissipated.

[0075] In particular, during sudden acceleration of an electric vehicle, the temperature of the relay 11 may rise suddenly and the heat energy generated by the relay 11 may temporarily become very large. However, the heat capacity portion 22 provided in the conductor block 20 allows the heat with large energy to be efficiently conducted to the conductor block 20 and then to the heat dissipation member 5.

[0076] In addition, in the battery disconnecting unit 1 according to this embodiment, the fastening portion 23 of the conductor block 20 has an insertion hole 23a through which the fastening member 50 is inserted.

[0077] With this configuration, the conductive block 20 and the electrical component 10 can be fixed together by inserting the fastening member 50 into the insertion hole 23a.

[0078] In the battery cutoff unit 1 according to this embodiment, the fastening member 50 is a screw having a screw head 51 and a screw shaft 52, and the screw shaft 52 is inserted through the insertion hole 23a and screwed into a screw hole provided in a terminal of the electrical component 10. Specifically, the screw shaft 52 is screwed into a screw hole 11a1 provided in the terminal 11a of the relay 11.

[0079] This configuration allows the conductor block 20 and the electrical component 10 (relay 11) to be fastened together by screws, thereby firmly fixing the conductor block 20 and the electrical component 10 together and efficiently conducting heat generated in the electrical component 10 from the terminals of the electrical component 10 (terminals 11a of the relay 11) to the heat conducting portion 21 of the conductor block 20.

[0080] In addition, in the battery disconnecting unit 1 according to this embodiment, the fastening portion 23 of the conductive block 20 is provided with a recess 23b for accommodating the screw head 51 of the fastening member 50, which is a screw.

[0081] With this configuration, the screw head 51 of the fastening member 50 (screw) can be stored in the recess 23b, preventing the screw head 51 from protruding toward the insulating sheet 40. This allows the conductor block 20 and the insulating sheet 40 to be closer together, allowing heat generated in the electrical component 10 to be conducted to the conductor block 20 and efficiently conducted to the insulating sheet 40. Furthermore, storing the screw head 51 in the recess 23b prevents the screw head 51 from pushing up against the insulating sheet 40 and the heat dissipation member 5. Furthermore, storing the screw head 51 in the recess 23b allows the battery cutoff unit 1 to be made smaller.

[0082] In addition, in the battery disconnecting unit 1 according to this embodiment, the fastening portion 23 of the conductor block 20 is provided on the heat conducting portion 21 .

[0083] This allows the heat conducting portion 21 to be connected to the electrical component 10 and fix the electrical component 10 to the conductor block 20, so that the heat generated in the electrical component 10 can be efficiently conducted to the conductor block 20 by the heat conducting portion 21.

[0084] Furthermore, in the battery cutoff unit 1 according to this embodiment, the volume of the heat capacity portion 22 in the conductor block 20 is larger than the volume of the heat conduction portion 21 .

[0085] This configuration allows the heat capacity of the heat capacity portion 22 to be increased, so that even if the heat energy generated by the electrical component 10 is large, the heat can be efficiently drawn into the conductor block 20 .

[0086] (Modifications) 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.

[0087] For example, in the above embodiment, the fastening portion 23 of the conductor block 20 is provided in the heat conduction portion 21, but this is not limiting. Specifically, the fastening portion 23 of the conductor block 20 may be provided in the heat capacity portion 22. In other words, the fastening portion 23, which is the portion connected to the terminal of the electrical component 10 by the fastening member 50, may be provided in either the heat conduction portion 21 or the heat capacity portion 22 of the conductor block 20.

[0088] In addition, in the above embodiment, the heat dissipation member 5 is not a part of the battery cutoff unit 1 but is an external member of the battery cutoff unit 1, but this is not limited to this. In other words, the heat dissipation member 5 may be a part of the battery cutoff unit 1, and the battery cutoff unit 1 may include the heat dissipation member 5.

[0089] Furthermore, in the above embodiment, the electrical component 10 includes the shunt resistor 13 as a current sensor, but this is not limited thereto. For example, the battery cutoff unit 1 may be provided with a current sensor other than the shunt resistor 13 as the electrical component 10. Specifically, the battery cutoff unit 1 may include a Hall sensor as the current sensor, which is the electrical component 10. Note that in the above embodiment, the electrical components 10 connected to the conductor block 20 are the relay 11, the fuse 12, and the shunt resistor 13, but this is not limited thereto. The battery cutoff unit 1 may include electrical components 10 connected to the conductor block 20 other than the relay 11, the fuse 12, and the shunt resistor 13.

[0090] In the above embodiment, the case 30, which is a resin case made of a resin member, has an opening on the lower surface, which is the surface facing the heat dissipation member 5. However, this is not limited to this. In other words, the lower surface of the case 30 does not have to be open, and the case 30 may have a bottom. In this case, the insulating sheet 40 is disposed between the case 30 and the heat dissipation member 5.

[0091] Furthermore, in the above embodiment, the battery cutoff unit 1 is installed on the heat dissipation member 5 so that the insulating sheet 40 arranged in the lower portion of the case 30 contacts the heat dissipation member 5, but this is not limited to this. For example, the battery cutoff unit 1 may further include a metal case that houses the entire resin case 30, and be installed on the heat dissipation member 5 so that the metal case contacts the heat dissipation member 5. In this case, the metal case contacts the insulating sheet 40. In other words, the insulating sheet 40 is sandwiched between the conductor block 20 and the metal case.

[0092] 2, in the above embodiment, the first module 1a, the second module 1b, and the third module 1c are arranged adjacent to each other, but this is not limiting. For example, depending on the system structure, it may be preferable for the first module 1a, the second module 1b, and the third module 1c to be arranged at separate locations rather than adjacent to each other.

[0093] 2, in the above embodiment, the battery cutoff unit 1 is configured by three modules, namely, the first module 1a, the second module 1b, and the third module 1c, but this is not limiting. For example, depending on the system configuration, it may be preferable to configure the battery cutoff unit 1 by one or two of the first module 1a, the second module 1b, and the third module 1c.

[0094] 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 may be used in electrical appliances such as home appliances.

[0095] Furthermore, although the technology of the present disclosure has been applied to the battery disconnecting unit 1, it is not limited thereto. The technology of the present disclosure may be used in disconnecting units other than the battery disconnecting unit 1, or in electrical junction boxes other than disconnecting units. For example, the technology of the present disclosure may be used in a charging unit connected to a battery.

[0096] In addition, this disclosure also includes forms obtained by making various modifications to the above embodiments that a person skilled in the art would think of, and forms realized by arbitrarily combining the components and functions in the embodiments within the scope of the present disclosure.

[0097] The technology of the present disclosure can be widely used in various products such as automobiles.

[0098] REFERENCE SIGNS LIST 1 battery cutoff unit 1a first module 1b second module 1c third module 2 battery 3 inverter 5 heat dissipation member 10 electrical component 11 relay 11a terminal 11a1 screw hole 11b relay housing 11c insulating plate 12 fuse 13 shunt resistor 20 conductor block 21 heat conduction portion 22 heat capacity portion 23 fastening portion 23a insertion hole 23b recess 30 case 30a first case portion 30b second case portion 30c third case portion 40 insulating sheet 50 fastening member 51 screw head 52 screw shaft 100 drive system

Claims

1. An electrical connection box comprising: an electrical component; and a die-cast conductor block, wherein the conductor block has a heat conduction portion and a heat capacity portion having a length in the thickness direction of the heat conduction portion that is greater than the thickness of the heat conduction portion, and wherein one of the heat conduction portion and the heat capacity portion is provided with a fastening portion that is connected to a terminal of the electrical component by a fastening member.

2. The electrical connection box according to claim 1, wherein the fastening portion has an insertion hole through which the fastening member is inserted.

3. The electrical connection box according to claim 2, wherein the fastening member is a screw having a screw head and a screw shaft, and the screw shaft is inserted into the insertion hole and screwed into a screw hole provided in a terminal of the electrical component.

4. The electrical junction box according to claim 3, wherein the fastening portion is provided with a recess for accommodating the head of the screw.

5. An electrical junction box according to any one of claims 2 to 4, wherein the fastening portion is provided on the heat conducting portion.

6. The electrical junction box according to any one of claims 1 to 5, wherein the volume of the heat capacity portion is larger than the volume of the heat conduction portion.

7. The electrical junction box according to any one of claims 1 to 6, wherein a plating film is formed on the surface of the conductor block.

8. The electrical junction box according to any one of claims 1 to 7, wherein the conductor block is made of an aluminum alloy or pure aluminum.

9. The electrical junction box according to any one of claims 1 to 8, wherein the conductor block is an insert-molded product in which at least a portion is embedded in a resin member.

10. The electrical junction box according to claim 9, wherein the conductor block is embedded in the resin member so that the surface facing the heat dissipation member on which the electrical junction box is installed is exposed.

11. The electrical junction box according to claim 10, wherein an insulating sheet is disposed on the surface of the conductor block that is exposed from the resin member.

12. The electrical connection box according to claim 9, further comprising an insulating sheet and a heat dissipation member, the resin member being a resin case, and the insulating sheet being disposed between the resin case and the heat dissipation member.

13. The electrical junction box according to any one of claims 1 to 12, wherein the electrical component is at least one of a relay, a fuse, and a current sensor.

14. The electrical junction box according to any one of claims 1 to 13, wherein the electrical junction box is a circuit breaking unit.

Images