Relay unit

Abstract

A high voltage JB (2), which is a relay unit, comprises a positive electrode bus bar (20p), a negative electrode bus bar (20n), an electric component, and a JB case (10). The electric component is at least one of a positive electrode SMR (30p), a negative electrode SMR (30n), a positive electrode charging relay (40p), a negative electrode charging relay (40n), a precharge relay (50), a pyrofuse (80), a precharge resistance (60), and a current sensor (70). Each of the relays is an electromagnetic relay apparatus that switches between energization and interruption of an output current from a battery. The pyrofuse (80) is a fuse that interrupts the output current from the battery. The precharge resistance (60) is a resistor that serves as an electrical resistance of the output current from the battery. The current sensor (70) detects the magnitude of the output current from the battery. At least one part of the electric component is interposed between the positive electrode bus bar (20p) and the negative electrode bus bar (20n).

Description

Relay Unit CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Patent Application No. 2024-001487 filed in Japan on January 9, 2024, the contents of which are incorporated by reference in their entirety.

[0002] TECHNICAL FIELD This disclosure relates to a relay unit.

[0003] Patent Document 1 discloses a relay unit electrically connected between a battery and an inverter, which includes a plurality of relays, which are electromagnetic relays, a plurality of bus bars, and a plurality of connection terminals.

[0004] The connection terminals include battery terminals connected to the positive and negative sides of the battery, respectively, and inverter terminals connected to the positive and negative sides of the inverter, respectively. The busbars include positive and negative busbars that form a current path between the battery terminals and the inverter terminals. The relays include a positive relay provided in the current path formed by the positive busbar, and a negative relay provided in the current path formed by the negative busbar.

[0005] US Patent Application Publication No. 2022 / 0200324

[0006] In Patent Document 1, the positive and negative bus bars are formed in a shape that connects the battery terminal and the inverter terminal via the shortest path, so that the positive and negative bus bars extend adjacent to each other.

[0007] Here, it is assumed that the busbars will be deformed if an external force such as a collision is applied to the relay unit. However, if the busbars of both poles extend adjacent to each other as described above, there is a concern that the busbars of both poles may come into contact with each other, causing an electrical short circuit.

[0008] The present disclosure aims to provide a relay unit that reduces the risk of an electrical short circuit caused by busbar deformation due to external force.

[0009] In order to achieve the above object, one disclosed aspect is a relay unit comprising: a positive bus bar that forms a current path between the positive side of the battery and the inverter; a negative bus bar that forms a current path between the negative side of the battery and the inverter; electrical components that are at least one of a relay that is an electromagnetic relay that switches between conducting and cutting off the output current from the battery, a fuse that cuts off the output current, a resistor that provides electrical resistance to the output current, and a current sensor that detects the magnitude of the output current; and a case that houses the positive bus bar, negative bus bar, and electrical components, with at least some of the electrical components interposed between the positive bus bar and the negative bus bar.

[0010] In this embodiment, at least a part of the electrical component is interposed between the positive bus bar and the negative bus bar. Therefore, even if at least one of the bus bars is deformed due to an impact or the like, the electrical component functions as a buffer between the two bus bars. This reduces the risk of the two bus bars coming into contact and causing a short circuit. Furthermore, the presence of the electrical component between the two bus bars means that the distance between the two bus bars is increased by the amount of space required to mount the electrical component. This reduces the risk of the two bus bars coming into contact and causing a short circuit.

[0011] Note that the reference numbers in parentheses above and in the claims merely indicate examples of correspondence with specific configurations in the embodiments described below, and do not limit the technical scope in any way. Furthermore, claims not explicitly stated in the claims may be combined together if there is no particular problem with the combination.

[0012] Fig. 1 is a diagram showing an electrical configuration of a high-voltage junction box according to a first embodiment of the present disclosure. Fig. 2 is an exploded perspective view of the high-voltage junction box according to the first embodiment. Fig. 3 is a perspective view showing an internal structure of the high-voltage junction box according to the first embodiment. Fig. 4 is a top view showing an internal structure of the high-voltage junction box according to the first embodiment. Fig. 5 is a perspective view showing a connection structure between a relay and a bus bar according to the first embodiment. Fig. 6 is a perspective view showing a layout of bus bars according to the first embodiment.

[0013] Hereinafter, several embodiments will be described with reference to the drawings. Note that corresponding components in each embodiment are given the same reference numerals, and redundant description may be omitted. When only a portion of the configuration is described in each embodiment, the configuration of another embodiment described previously can be applied to the remaining portion of the configuration. Furthermore, in addition to the combinations of configurations explicitly stated in the description of each embodiment, configurations of several embodiments can also be partially combined together even if not explicitly stated, as long as there is no particular problem with the combination.

[0014] (First embodiment) A high-voltage junction box (hereinafter referred to as high-voltage JB) according to a first embodiment of the present disclosure shown in Fig. 1 is used in an electric vehicle such as a battery electric vehicle (BEV). The high-voltage JB 2 is mounted on the electric vehicle together with a battery 3, an inverter 4, a charging inlet 5, etc. The high-voltage JB 2 is electrically connected to the battery 3, the inverter 4, the charging inlet 5, etc.

[0015] The battery 3 is an electricity storage device that stores power for propelling the electric vehicle. The battery 3 includes a rechargeable secondary battery such as a lithium-ion battery or a nickel-metal hydride battery. The inverter 4 is electrically connected to a motor generator 6 for propulsion. The motor generator 6 is a permanent magnet type or wound field type synchronous motor, an induction motor, or the like.

[0016] The inverter 4 controls the rotational speed and torque of the motor generator 6. A smoothing capacitor 4C is connected in parallel to the inverter 4. The smoothing capacitor 4C smoothes the current from the battery 3 that is supplied to the inverter 4 via the high-voltage JB2. A charging cable from a charging stand provided outside the vehicle is connected to the charging inlet 5. DC power is applied to the charging inlet 5 to rapidly charge the battery 3. The charging inlet 5 supplies the DC power input from the charging stand to the high-voltage JB2.

[0017] The high-voltage JB 2 includes a power control circuit 10a and a JB case 10 (see FIG. 2) that protects the power control circuit 10a. The power control circuit 10a includes a plurality of current paths. The power control circuit 10a switches between the plurality of current paths.

[0018] The power control circuit 10a includes a pair of battery terminals (hereinafter referred to as BAT terminals) 11p, 11n, inverter terminals (hereinafter referred to as INV terminals) 12p, 12n, and charging terminals 13p, 13n. Elements marked with "p" are components on the positive side, and elements marked with "n" are components on the negative side (ground side).

[0019] The BAT terminals 11p and 11n are terminals used to electrically connect the high-voltage JB2 and the battery 3. The BAT terminal 11p is connected to the positive electrode side of the battery 3. The BAT terminal 11n is connected to the negative electrode side of the battery 3. The INV terminals 12p and 12n are terminals used to electrically connect the high-voltage JB2 and the inverter 4. The INV terminal 12p is connected to the positive electrode side of the inverter 4. The INV terminal 12n is connected to the negative electrode side of the inverter 4.

[0020] The charging terminals 13p and 13n are terminal portions used for electrically connecting the high-voltage JB 2 and the charging inlet 5. The charging terminal 13p is connected to the positive electrode side of the charging inlet 5. The charging terminal 13n is connected to the negative electrode side of the charging inlet 5. Power for charging the battery 3 is supplied to the charging terminals 13p and 13n.

[0021] The power control circuit 10a further includes a positive bus bar 20p, a negative bus bar 20n, a positive system main relay (hereinafter referred to as a positive SMR) 30p, a negative system main relay (hereinafter referred to as a negative SMR) 30n, a positive charging relay 40p, and a negative charging relay 40n. The power control circuit 10a further includes a pre-charge relay 50, a pre-charge resistor 60, a current sensor 70, and a pyro-fuse 80.

[0022] 1 , the positive bus bar 20p forms a current path between the positive electrode side of the battery 3 and the inverter 4. The negative bus bar 20n forms a current path between the negative electrode side of the battery 3 and the inverter 4. The positive bus bar 20p and the negative bus bar 20n are conductive members formed of a metal material with excellent conductivity, such as copper, and have a plate shape. These bus bars are capable of carrying a large current that is sufficient to cause the motor generator 6 to generate driving force for the vehicle, and form multiple current paths in the power control circuit 10a.

[0023] The positive busbars 20p include a positive inverter busbar (hereinafter referred to as a positive INV busbar) 21p, a positive charging busbar 22p, and a positive battery busbar (hereinafter referred to as a positive BAT busbar) 23p. In other words, these multiple busbars are electrically connected to form part of a current path through the positive busbar 20p. The negative busbars 20n include a negative inverter busbar (hereinafter referred to as a negative INV busbar) 21n, a negative charging busbar 22n, and a negative battery busbar (hereinafter referred to as a negative BAT busbar) 23n.

[0024] The positive INV bus bar 21p forms a current path between the inverter 4 and the positive SMR 30p. Specifically, one end of the positive INV bus bar 21p is connected to the INV terminal 12p, and the other end is connected to the positive SMR 30p. The negative INV bus bar 21n forms a current path between the inverter 4 and the negative SMR 30n. Specifically, one end of the negative INV bus bar 21n is connected to the INV terminal 12n, and the other end is connected to the negative SMR 30n.

[0025] The positive electrode charging busbar 22p forms a current path between the charging inlet 5 and the positive electrode charging relay 40p. Specifically, one end of the positive electrode charging busbar 22p is connected to the charging terminal 13p, and the other end is connected to the positive electrode charging relay 40p. The negative electrode charging busbar 22n forms a current path between the charging inlet 5 and the negative electrode charging relay 40n. Specifically, one end of the negative electrode charging busbar 22n is connected to the charging terminal 13n, and the other end is connected to the negative electrode charging relay 40n.

[0026] The positive BAT bus bar 23p forms a current path between the battery 3 and the positive SMR 30p. Specifically, one end of the positive BAT bus bar 23p is connected to the BAT terminal 11p, and the other end is connected to the positive SMR 30p. The negative BAT bus bar 23n forms a current path between the battery 3 and the negative SMR 30n. Specifically, one end of the negative BAT bus bar 23n is connected to the BAT terminal 11n, and the other end is connected to the negative SMR 30n.

[0027] <Relays> The positive SMR 30p corresponds to a "positive relay" and is located between the positive BAT bus bar 23p and the positive INV bus bar 21p. The negative SMR 30n corresponds to a "negative relay" and is located between the negative BAT bus bar 23n and the negative INV bus bar 21n. The pre-charge relay 50 is connected in parallel to the negative SMR 30n. The positive SMR 30p, the negative SMR 30n, and the pre-charge relay 50 switch the state of the current path between the battery 3 and the inverter 4 between a conducting state (ON) and a non-conducting state (OFF).

[0028] The positive electrode charging relay 40p is located between the positive electrode SMR 30p and the positive electrode charging bus bar 22p. The positive electrode charging relay 40p is connected in parallel to the positive electrode SMR 30p. The negative electrode charging relay 40n is located between the negative electrode SMR 30n and the negative electrode charging bus bar 22n. The negative electrode charging relay 40n is connected in parallel to the negative electrode SMR 30n. The positive electrode charging relay 40p and the negative electrode charging relay 40n switch the state of the current path between the battery 3 and the charging inlet 5 between a conducting state (ON) and a non-conducting state (OFF).

[0029] The operation of each of the positive SMR 30p, negative SMR 30n, pre-charge relay 50, positive charging relay 40p, and negative charging relay 40n is individually controlled by a control device 90 (see FIG. 2) mounted on the vehicle. The control device 90 includes an arithmetic processing circuit including a processor, RAM (Random Access Memory), storage, etc. For example, the control device 90 includes a control board 91 and a microcomputer (hereinafter referred to as MCU) 92. The MCU 92 provides the processor, RAM, storage, etc. The arithmetic processing circuit is provided by the control board 91, the MCU 92, and various electronic components mounted on the control board 91.

[0030] The arithmetic processing circuit of the control device 90 outputs control signals for controlling the on / off switching to each of the various relays described above. In short, these various relays switch current paths, which are multiple current paths including the various bus bars described above and through which large DC currents of tens to hundreds of amperes flow, in accordance with control signals obtained from the control device 90.

[0031] The various relays described above all have the same structure and specifications. The structure of the relay will be described below using the positive SMR 30p as an example. The positive SMR 30p includes a fixed core, a movable core, a rod, an excitation coil, a pressure spring, a movable terminal 33p (see FIG. 1 ), a pair of fixed terminals 31pH and 31pL, and a relay case 32p. The relay case 32p contains the fixed core, the movable core, the rod, the excitation coil, the pressure spring, the movable terminal, and the pair of fixed terminals 31pH and 31pL. Portions of the pair of fixed terminals 31pH and 31pL are exposed from the relay case 32p and connected to the positive bus bar 20p described above.

[0032] When the electromagnetic coil is excited by a control signal output from the control device 90, the movable core is attracted to the fixed core and operates. A rod is attached to the movable core, and a movable terminal is attached to the rod. The movable terminal moves as the movable core operates and abuts against the pair of fixed terminals 31pH, 31pL. As a result, the pair of fixed terminals 31pH, 31pL are electrically connected by the movable terminal and enter a conducting state (ON). When the output of the control signal is stopped and the excitation of the electromagnetic coil is stopped, the pressure spring pushes the movable core back to its original position before excitation, and the movable terminal moves away from the pair of fixed terminals 31pH, 31pL. As a result, the pair of fixed terminals 31pH, 31pL enter a non-conducting state (OFF).

[0033] Of the pair of fixed terminals 31pH, 31pL of the positive electrode SMR 30p, the fixed terminal 31pH is a terminal on the high voltage side, and the fixed terminal 31pL is a terminal on the low voltage side. Elements with a reference symbol "H" are components on the high voltage side. Elements with a reference symbol "L" are components on the low voltage side.

[0034] In this embodiment, the pair of fixed terminals 31pH, 31pL housed in the relay case 32p of the positive SMR 30p corresponds to the "positive terminals." The pair of fixed terminals 31nH, 31nL housed in the relay case 32n of the negative SMR 30n corresponds to the "negative terminals." The pair of fixed terminals 41pH, 41pL housed in the relay case 42p of the positive charging relay 40p corresponds to the "positive charging terminals." The pair of fixed terminals 41nH, 41nL housed in the relay case 42n of the negative charging relay 40n corresponds to the "negative charging terminals." As shown in FIG. 1 , the positive terminal and the positive charging terminal are connected to the positive bus bar 20p. The negative terminal and the negative charging terminal are connected to the negative bus bar 20n.

[0035] The connection relationship between the busbars and relays will be described in more detail below with reference to Figures 2 to 6. The fixed terminal 31pH of the positive SMR 30p is connected to the connection portion 23p1 of the positive BAT busbar 23p. The fixed terminal 31pL is connected to the connection portion 21p1 of the positive INV busbar 21p. The fixed terminal 41pH of the positive charging relay 40p is connected to the connection portion 23p2 of the positive BAT busbar 23p. The fixed terminal 41pL is connected to the connection portion 22p1 of the positive charging busbar 22p.

[0036] The fixed terminal 31nH of the negative SMR 30n is connected to the connection portion 23n1 of the negative BAT bus bar 23n. The fixed terminal 31nL is connected to the connection portion 21n1 of the negative INV bus bar 21n. The fixed terminal 41nH of the negative charging relay 40n is connected to the connection portion 23n2 of the negative BAT bus bar 23n. The fixed terminal 41nL is connected to the connection portion 22n1 of the negative charging bus bar 22n.

[0037] In this embodiment, bolts are used to connect the terminals of the various relays to the bus bars, but the connection is not limited to bolts and may be made by, for example, crimping, riveting, crimping, or welding.

[0038] As shown in Fig. 4, a positive electrode insulating plate 35p is provided in the relay case 32p of the positive electrode SMR 30p. The positive electrode insulating plate 35p is made of electrically insulating resin and is molded integrally with the relay case 32p. The positive electrode insulating plate 35p is disposed between the pair of fixed terminals 31pL and 31pH. The positive electrode insulating plate 35p has a plate shape and is disposed so as to separate the pair of fixed terminals 31pL and 31pH.

[0039] As shown in Figures 4 and 2, a negative electrode insulating plate 35n is provided in the relay case 32n of the negative electrode SMR 30n. The negative electrode insulating plate 35n is made of electrically insulating resin and is molded integrally with the relay case 32n. The negative electrode insulating plate 35n is disposed between the pair of fixed terminals 31nL and 31nH. The negative electrode insulating plate 35n has a plate shape and is disposed so as to separate the pair of fixed terminals 31nL and 31nH.

[0040] As shown in Fig. 4, a positive electrode insulating plate 45p is provided in the relay case 42p of the positive electrode charging relay 40p. The positive electrode insulating plate 45p is made of electrically insulating resin and is molded integrally with the relay case 42p. The positive electrode insulating plate 45p is disposed between the pair of fixed terminals 41pL, 41pH. The positive electrode insulating plate 45p has a plate shape and is disposed so as to separate the pair of fixed terminals 41pL, 41pH.

[0041] As shown in Figures 4 and 2, a negative electrode insulating plate 45n is provided in the relay case 42n of the negative electrode charging relay 40n. The negative electrode insulating plate 45n is made of electrically insulating resin and is molded integrally with the relay case 42n. The negative electrode insulating plate 45n is disposed between the pair of fixed terminals 41nL, 41nH. The negative electrode insulating plate 45n has a plate shape and is disposed so as to separate the pair of fixed terminals 41nL, 41nH.

[0042] The pre-charge resistor 60 is a resistor connected in series with the pre-charge relay 50. The pre-charge resistor 60 and the pre-charge relay 50 form a current path that bypasses the negative SMR 30n between the negative BAT bus bar 23n and the negative INV bus bar 21n. The pre-charge resistor 60 reduces the charging current (inrush current) that flows through the smoothing capacitor 4C when the pre-charge relay 50 is switched to the energized state (on state).

[0043] For example, if the positive SMR 30p and the negative SMR 30n are energized when the charge stored in the smoothing capacitor 4C is low, there is a concern that the above-mentioned inrush current may occur and cause damage to the equipment. Therefore, when the charge in the smoothing capacitor 4C is low, such as during startup, the pre-charge relay 50 is energized before the positive SMR 30p and the negative SMR 30n. This allows the charge in the smoothing capacitor 4C to be increased through a current path via the pre-charge resistor 60. Thereafter, the positive SMR 30p and the negative SMR 30n are energized, and power is supplied to the inverter 4 without passing through the pre-charge resistor 60.

[0044] The current sensor 70 is provided on the negative BAT bus bar 23n and detects the magnitude of the current (output current) output from the battery 3. The current sensor 70 has a magnetic core and a Hall element (not shown). The magnetic core is formed in an annular shape and is arranged to surround the negative BAT bus bar 23n to be measured. The Hall element detects magnetic flux generated in the magnetic core by the current flowing through the negative BAT bus bar 23n. The current sensor 70 measures the current flowing through the negative BAT bus bar 23n by detecting changes in the output voltage of the Hall element.

[0045] The pyrofuse 80 is provided on the negative BAT bus bar 23n and functions as a current breaker. The pyrofuse 80 automatically breaks when an abnormally large current occurs in the negative BAT bus bar 23n. The pyrofuse 80 protects the other components of the power control circuit 10a, the inverter 4, etc. from overcurrent by cutting off the connection with the battery 3. The pyrofuse 80 has an igniter 81, a piston (not shown), and a bus bar 82 to be cut.

[0046] For example, if the current value detected by the current sensor 70 exceeds a predetermined threshold, the microcomputer 92 outputs an ignition current to the igniter 81. When the ignition current is input, the igniter 81 burns and generates gas. The piston is pushed down by the pressure of the gas generated by the igniter 81, cutting the bus bar 82 to be cut. The bus bar 82 to be cut is connected to the negative BAT bus bar 23n so as to form part of the current path through the negative BAT bus bar 23n. Therefore, when the bus bar 82 to be cut is cut by the piston as described above, the current path through the negative BAT bus bar 23n is interrupted. As a result, when an abnormally large current occurs, the current path through the negative bus bar 20n is interrupted.

[0047] <Positional Relationship of Each Component> The high-voltage JB 2 corresponds to the "relay unit." The positive SMR 30p, negative SMR 30n, positive charging relay 40p, negative charging relay 40n, pre-charge relay 50, pyro fuse 80, pre-charge resistor 60, and current sensor 70 correspond to the "electrical components." These electrical components are housed in a JB case 10. The JB case 10 has a resin base plate 11 and a resin cover 12. Each of the electrical components is fixed to the base plate 11 with screws or the like. Note that FIGS. 3 and 4 show the high-voltage JB 2 with the cover 12 removed from the base plate 11.

[0048] As shown in FIG. 4, the positive SMR 30p and the positive charging relay 40p are arranged adjacent to each other along a predetermined first direction (X direction). The positive SMR 30p and the negative SMR 30n are arranged adjacent to each other along a second direction (Y direction) perpendicular to the first direction. The Z direction indicated by the arrow in the figure is perpendicular to the X direction and the Y direction. Note that the up-down direction when the high-voltage JB2 is mounted on a vehicle coincides with the Z direction. The positive SMR 30p and the positive charging relay 40p are arranged at the same position in the Z direction.

[0049] As shown in Figure 5, the fixed terminal 31pL of the positive SMR 30p and the fixed terminal 41pL of the positive charging relay 40p are arranged side by side in the X direction. These fixed terminals 31pL, 41pL are arranged at the same position in the Y and Z directions. The fixed terminal 31pH of the positive SMR 30p and the fixed terminal 41pH of the positive charging relay 40p are arranged side by side in the X direction. These fixed terminals 31pH, 41pH are arranged at the same position in the Y and Z directions.

[0050] As shown in Fig. 4, the negative electrode SMR 30n and the negative electrode charging relay 40n are arranged side by side along a predetermined first direction (X direction). As shown in Fig. 2, the fixed terminal 31nL of the negative electrode SMR 30n and the fixed terminal 41nL of the negative electrode charging relay 40n are arranged side by side along the X direction. These fixed terminals 31nL, 41nL are arranged at the same position in the Y direction and the Z direction. The fixed terminal 31nH of the negative electrode SMR 30n and the fixed terminal 41nH of the negative electrode charging relay 40n are arranged side by side along the X direction. These fixed terminals 31nH, 41nH are arranged at the same position in the Y direction and the Z direction.

[0051] In other words, the positive SMR 30p is attached to the base plate 11 so that the pair of fixed terminals 31pL, 31pH of the positive SMR 30p are aligned in the Z direction. The negative SMR 30n is attached to the base plate 11 so that the pair of fixed terminals 31nL, 31nH of the negative SMR 30n are aligned in the Z direction. Furthermore, the positive charging relay 40p is attached to the base plate 11 so that the pair of fixed terminals 41pL, 41pH of the positive charging relay 40p are aligned in the Z direction. The negative charging relay 40n is attached to the base plate 11 so that the pair of fixed terminals 41nL, 41nH of the negative charging relay 40n are aligned in the Z direction.

[0052] The positive electrode SMR 30p and the negative electrode SMR 30n are attached to the base plate 11 so that the fixed terminals 31pL and 31pH of the positive electrode SMR 30p and the fixed terminals 31nL and 31nH of the negative electrode SMR 30n face in opposite directions. That is, the fixed terminals 31pL and 31pH face in the Y direction opposite the negative electrode SMR 30n. The fixed terminals 31nL and 31nH face in the Y direction opposite the positive electrode SMR 30p.

[0053] Furthermore, the positive electrode charging relay 40p and the negative electrode charging relay 40n are attached to the base plate 11 so that the fixed terminals 41pL, 41pH of the positive electrode charging relay 40p and the fixed terminals 41nL, 41nH of the negative electrode charging relay 40n face in opposite directions. That is, the fixed terminals 41pL, 41pH face in the Y direction opposite the negative electrode charging relay 40n. The fixed terminals 41nL, 41nH face in the Y direction opposite the positive electrode charging relay 40p.

[0054] The positive electrode SMR 30p, the negative electrode SMR 30n, the positive electrode charging relay 40p, and the negative electrode charging relay 40n are arranged between the positive electrode bus bar 20p and the negative electrode bus bar 20n. Similarly, the pre-charge relay 50, the pyro-fuse 80, the pre-charge resistor 60, and the current sensor 70 are arranged between the positive electrode bus bar 20p and the negative electrode bus bar 20n. The arrangement of these components will be described in more detail below.

[0055] <Wall Surface Facing Portions> As shown in FIG. 6 , the positive bus bar 20p has multiple positive electrode wall surface facing portions p1 to p6. The negative bus bar 20n has multiple negative electrode wall surface facing portions n1 to n7. The dotted areas in FIG. 6 correspond to the positive electrode wall surface facing portions p1 to p6 and the negative electrode wall surface facing portions n1 to n7. These wall surface facing portions are portions of the plate surfaces of the bus bars that face the wall surfaces of the case 10. The plate surfaces of the wall surface facing portions are parallel to the plate surface of the case 10, which extends perpendicular to the Y direction. The positive electrode SMR 30p, the negative electrode SMR 30n, the positive electrode charging relay 40p, and the negative electrode charging relay 40n are arranged between the positive electrode wall surface facing portions p1 to p6 and the negative electrode wall surface facing portions n1 to n7.

[0056] The positive charging busbar 22p has positive wall surface facing portions p1, p2, and p3, and the negative charging busbar 22n has negative wall surface facing portions n1, n2, and n3. The positive INV busbar 21p has a positive wall surface facing portion p4, and the negative INV busbar 21n has a negative wall surface facing portion n4. The positive BAT busbar 23p has positive wall surface facing portions p5 and p6, and the negative BAT busbar 23n has negative wall surface facing portions n5, n6, and n7.

[0057] The positive electrode charging relay 40p and the negative electrode charging relay 40n are located between the positive electrode wall surface facing portions p2, p3, and p5 and the negative electrode wall surface facing portions n2, n3, and n5. The positive electrode SMR 30p and the negative electrode SMR 30n are located between the positive electrode wall surface facing portions p2, p4, and p5 and the negative electrode wall surface facing portions n2, n4, and n5.

[0058] The pre-charge relay 50 is located between the positive electrode wall surface facing portion p1 and the negative electrode wall surface facing portion n1. The pyro-fuse 80 is located between the positive electrode wall surface facing portion p6 and the negative electrode wall surface facing portion n7. The pre-charge resistor 60 is located between the positive electrode wall surface facing portion p6 and the negative electrode wall surface facing portion n6. The current sensor 70 is located between the positive electrode wall surface facing portion p6 and the negative electrode wall surface facing portion n7.

[0059] As explained above, "an electrical component is disposed between the positive bus bar 20p and the negative bus bar 20n" means that at least a portion of the electrical component is located in the region between the positive bus bar 20p and the negative bus bar 20n. "The region between the positive bus bar 20p and the negative bus bar 20n" means the range obtained by projecting the positive bus bar 20p onto the negative bus bar 20n, or the range obtained by projecting the negative bus bar 20n onto the positive bus bar 20p. Furthermore, a portion of one electrical component may be located in the region, or the entirety of one electrical component may be located in the region.

[0060] (Summary of First Embodiment) Here, an external force may be applied to the high-voltage JB 2 due to, for example, a collision of a vehicle equipped with the high-voltage JB 2. For example, when an external force is applied in the direction indicated by the closed arrow in FIG. 4 , the negative charging bus bar 22n deforms toward the inside of the JB case 10, as indicated by the dashed line. Therefore, if the positive bus bar 20p and the negative bus bar 20n extend adjacent to each other, there is a risk that the positive bus bar 20p and the negative bus bar 20n may come into contact with each other, causing an electrical short circuit.

[0061] To address this concern, in this embodiment, at least a portion of an electrical component is interposed between the positive bus bar 20p and the negative bus bar 20n. Therefore, even if at least one of the positive bus bar 20p and the negative bus bar 20n is deformed by an external force such as an impact, the electrical component functions as a buffer between the two bus bars. This reduces the risk of the two bus bars coming into contact and causing a short circuit. Furthermore, the presence of an electrical component between the two bus bars means that the distance between the two bus bars is increased by the amount of space required to mount the electrical component. This reduces the risk of the two bus bars coming into contact and causing a short circuit.

[0062] Furthermore, in this embodiment, both the positive electrode SMR 30p and the negative electrode SMR 30n are interposed between the positive electrode bus bar 20p and the negative electrode bus bar 20n, thereby improving the function of the SMRs (electrical components) as buffers between the two bus bars.

[0063] Furthermore, in this embodiment, the positive electrode SMR 30p and the negative electrode SMR 30n are arranged so that the fixed terminals 31pH, 31pL (positive electrode terminals) and 31nH, 31nL (negative electrode terminals) face opposite each other. This positions the positive electrode terminal and the negative electrode terminal away from each other. As a result, the portion of the positive electrode bus bar 20p connected to the positive electrode terminal and the portion of the negative electrode bus bar 20n connected to the negative electrode terminal are positioned away from each other. This further reduces the risk of the two bus bars coming into contact and causing a short circuit when the bus bars are deformed by an external force.

[0064] Furthermore, in this embodiment, the positive electrode SMR 30p includes a positive electrode insulating plate 35p disposed between the pair of fixed terminals 31pL and 31pH (positive electrode terminals). This reduces the risk of short-circuiting due to contact between the portion of the positive electrode bus bar 20p connected to the fixed terminal 31pL and the portion connected to the fixed terminal 31pH when the bus bar is deformed by an external force. This reduces the risk of the positive electrode SMR 30p unintentionally becoming conductive.

[0065] Furthermore, in this embodiment, the negative electrode SMR 30n includes a negative electrode insulating plate 35n disposed between the pair of fixed terminals 31nL and 31nH (negative electrode terminals). This reduces the risk of short-circuiting due to contact between the portion of the negative electrode busbar 20n connected to the fixed terminal 31nL and the portion connected to the fixed terminal 31nH when the busbar is deformed by an external force. This reduces the risk of the negative electrode SMR 30n becoming unintentionally energized.

[0066] Furthermore, in this embodiment, both the positive electrode charging relay 40p and the negative electrode charging relay 40n are interposed between the positive electrode bus bar 20p and the negative electrode bus bar 20n, thereby improving the function of the charging relays (electrical components) as buffers between the two bus bars.

[0067] Furthermore, in this embodiment, the positive electrode charging relay 40p and the negative electrode charging relay 40n are arranged so that the fixed terminals 41pH, 41pL (positive electrode charging terminals) and the fixed terminals 41nH, 41nL (negative electrode charging terminals) face opposite each other. This positions the positive electrode charging terminal and the negative electrode charging terminal away from each other. As a result, the portion of the positive electrode bus bar 20p connected to the positive electrode charging terminal and the portion of the negative electrode bus bar 20n connected to the negative electrode charging terminal are positioned away from each other. This further reduces the risk of the positive electrode bus bar 20p and the negative electrode bus bar 20n coming into contact and causing a short circuit when at least one of them is deformed by an external force.

[0068] Furthermore, in this embodiment, the high-voltage fixed terminal 31pH of the pair of positive electrode terminals of the positive electrode SMR 30p and the high-voltage fixed terminal 41pH of the pair of positive electrode charging terminals of the positive electrode charging relay 40p are arranged to be aligned in a first direction (X direction). Furthermore, the low-voltage fixed terminal 31pL of the pair of positive electrode terminals and the low-voltage fixed terminal 41pL of the pair of positive electrode charging terminals are arranged to be aligned in the first direction. Therefore, when the positive electrode bus bar 20p connects terminals aligned in the first direction, a large portion of the positive electrode bus bar 20p extends in the first direction.

[0069] Furthermore, the high-voltage fixed terminal 31nH of the pair of negative terminals of the negative SMR 30n and the high-voltage fixed terminal 41nH of the pair of negative charging terminals of the negative charging relay 40n are arranged to be aligned in the first direction. Furthermore, the low-voltage fixed terminal 31nL of the pair of negative terminals and the low-voltage fixed terminal 41nL of the pair of negative charging terminals are arranged to be aligned in the first direction. Therefore, when the negative busbar 20n connects terminals aligned in the first direction, a large portion of the negative busbar 20n extends in the first direction.

[0070] In short, with the above-described arrangement of the fixed terminals, the positive bus bar 20p and the negative bus bar 20n each have a large portion extending in the first direction. In other words, the area sandwiched between the two bus bars can be efficiently enlarged. Therefore, it is possible to easily interpose electrical components between the positive bus bar 20p and the negative bus bar 20n while achieving a layout that shortens the lengths of the two bus bars. Moreover, since it is easier to concentratively arrange multiple electrical components interposed between the two bus bars in a space-saving manner, it is also possible to reduce the size of the high-voltage JB 2.

[0071] Here, the positive bus bar 20p and the negative bus bar 20n, which carry a large current, generate heat when energized. As a result, there are concerns about thermal damage to electronic components such as the microcontroller 92 and increased electrical resistance. In consideration of this, in this embodiment, the positive bus bar 20p has positive wall-facing portions p1, p2, p3, p4, p5, and p6 that face the wall of the case 10. The negative bus bar 20n has negative wall-facing portions n1, n2, n3, n4, n5, n6, and n7 that face the wall of the case 10. Electrical components are interposed at least between the positive wall-facing portion and the negative wall-facing portion. This promotes heat dissipation from the bus bar's wall-facing portion to the case 10. It is expected that the case 10 will be cooled by the outside air. These factors reduce the above-mentioned concerns.

[0072] (Other Embodiments) Although multiple embodiments of the present disclosure have been described above, the present disclosure should not be construed as being limited to the above-described embodiments, and can be applied to various embodiments and combinations within the scope that does not deviate from the gist of the present disclosure.

[0073] In the above embodiment, the positive electrode charging relay 40p is connected in parallel to the positive electrode SMR 30p, but may be connected in series. In the above embodiment, the negative electrode charging relay 40n is connected in parallel to the negative electrode SMR 30n, but may be connected in series.

[0074] In the above embodiment, electrical components are interposed between the positive bus bar 20p and the negative bus bar 20n. These electrical components include all of the positive SMR 30p, the negative SMR 30n, the positive charging relay 40p, the negative charging relay 40n, the pre-charge relay 50, the pyro-fuse 80, the pre-charge resistor 60, and the current sensor 70. However, it is sufficient if at least one of these electrical components is interposed between the positive bus bar 20p and the negative bus bar 20n.

[0075] In the above embodiment, both the positive SMR 30p and the negative SMR 30n are interposed between the positive bus bar 20p and the negative bus bar 20n, but a layout in which either one of them is interposed may also be used. Also, in the above embodiment, both the positive charging relay 40p and the negative charging relay 40n are interposed between the positive bus bar 20p and the negative bus bar 20n, but a layout in which either one of them is interposed may also be used.

[0076] In the above embodiment, the positive electrode SMR 30p and the negative electrode SMR 30n are aligned in the same direction as the positive electrode bus bar 20p and the negative electrode bus bar 20n (Y direction). In contrast, the positive electrode SMR 30p and the negative electrode SMR 30n may be aligned in the X direction or the Z direction. Also, in the above embodiment, the positive electrode charging relay 40p and the negative electrode charging relay 40n are aligned in the same direction as the positive electrode bus bar 20p and the negative electrode bus bar 20n (Y direction). In contrast, the positive electrode charging relay 40p and the negative electrode charging relay 40n may be aligned in the X direction or the Z direction.

[0077] In the above embodiment, the positive SMR 30p and the positive charging relay 40p are aligned in the same direction as the longitudinal direction (X direction) of the positive wall surface facing portions p1 to p6 of the positive bus bar 20p. In contrast, the positive SMR 30p and the positive charging relay 40p may be aligned in the Y direction or the Z direction. Also, in the above embodiment, the negative SMR 30n and the negative charging relay 40n are aligned in the same direction as the longitudinal direction (X direction) of the negative wall surface facing portions n1 to n7 of the negative bus bar 20n. In contrast, the negative SMR 30n and the negative charging relay 40n may be aligned in the Y direction or the Z direction.

[0078] In the above embodiment, the relay unit of the present disclosure is used in a high-voltage JB2 mounted on an electric vehicle. However, the relay unit can also be used for purposes other than electric vehicles. For example, the relay unit of the present disclosure may be mounted on various moving objects such as railcars, trams, drones, and electric aircraft such as eVTOLs.

[0079] (Disclosure of Technical Ideas) This specification discloses multiple technical ideas described in the following multiple clauses. Some clauses may be described in a multiple dependent form, with the subsequent clause alternatively referring to the preceding clause. Furthermore, some clauses may be described in a multiple dependent form, with the subsequent clause referring to another multiple dependent clause. These multiple dependent clauses define multiple technical ideas.

[0080] (Technical Idea 1) A relay unit comprising: a positive bus bar (20p) that forms a current path between a positive side of a battery (3) and an inverter (4); a negative bus bar (20n) that forms a current path between the negative side of the battery and the inverter; electrical components that are at least one of a relay (30p, 30n, 40p, 40n, 50) that is an electromagnetic relay that switches between conducting and cutting off an output current from the battery, a fuse (80) that cuts off the output current, a resistor (60) that provides electrical resistance to the output current, and a current sensor (70) that detects the magnitude of the output current; and a case (10) that houses the positive bus bar, the negative bus bar, and the electrical components, wherein at least a portion of the electrical components are interposed between the positive bus bar and the negative bus bar.

[0081] (Technical Idea 2) The electrical component includes the relay, and the relay includes a positive relay (30p) having a pair of positive terminals (31pH, 31pL) connected to the positive bus bar, and a negative relay (30n) having a pair of negative terminals (31nH, 31nL) connected to the negative bus bar, and both the positive relay and the negative relay are interposed between the positive bus bar and the negative bus bar. This is the relay unit according to Technical Idea 1.

[0082] (Technical Concept 3) The relay unit according to Technical Concept 2, wherein the positive electrode relay and the negative electrode relay are arranged such that the positive electrode terminal and the negative electrode terminal face in opposite directions.

[0083] (Technical Idea 4) A relay unit according to Technical Idea 2 or 3, wherein the positive relay has a positive insulating plate (35p) which is an electrically insulating member arranged between the pair of positive terminals, and the negative relay has a negative insulating plate (35n) which is an electrically insulating member arranged between the pair of negative terminals.

[0084] (Technical Idea 5) A relay unit according to any one of Technical Ideas 1 to 4, wherein the electrical components include charging relays (40p, 40n) that switch between conducting and cutting off the charging current flowing between the battery and the charging inlet (5), and the charging relays include a positive electrode charging relay (40p) having a pair of positive electrode charging terminals (41pH, 41pL) connected to the positive electrode bus bar, and a negative electrode charging relay (40n) having a pair of negative electrode charging terminals (41nH, 41nL) connected to the negative electrode bus bar, and both the positive electrode charging relay and the negative electrode charging relay are interposed between the positive electrode bus bar and the negative electrode bus bar.

[0085] (Technical Concept 6) The relay unit according to Technical Concept 5, wherein the positive electrode charging relay and the negative electrode charging relay are arranged so that the positive electrode charging terminal and the negative electrode charging terminal face in opposite directions.

[0086] (Technical Idea 7) The electrical component includes a charging relay (40p, 40n) that switches between energizing and cutting off a charging current flowing between the battery and a charging inlet (5), and the charging relay includes a positive charging relay (40p) having a pair of positive charging terminals (41pH, 41pL) connected to the positive bus bar, and a negative charging relay (40n) having a pair of negative charging terminals (41nH, 41nL) connected to the negative bus bar, and the positive charging relay and the negative charging relay are arranged so that the positive charging terminal and the negative charging terminal face opposite each other, and the positive bus bar includes a positive inverter bus bar (21p) that forms a current path between the inverter and the positive relay, a positive charging bus bar (22p) that forms a current path between the charging inlet and the positive charging relay, and a positive battery bus bar (23p) that forms a current path between the battery and the positive relay, the negative busbar includes a negative inverter busbar (21n) that forms a current path between the inverter and the negative relay, a negative charging busbar (22n) that forms a current path between the charging inlet and the negative charging relay, and a negative battery busbar (23n) that forms a current path between the battery and the negative relay; the positive relay and the positive charging relay are arranged to be aligned in a predetermined first direction; the negative relay and the negative charging relay are arranged to be aligned in a predetermined second direction; the high-voltage terminal of the pair of positive terminals and the high-voltage terminal of the pair of positive charging terminals are arranged to be aligned in the first direction; the low-voltage terminal of the pair of positive terminals and the low-voltage terminal of the pair of positive charging terminals are arranged to be aligned in the first direction; the high-voltage terminal of the pair of negative terminals and the high-voltage terminal of the pair of negative charging terminals are arranged to be aligned in the second direction; A relay unit as described in Technical Idea 3, wherein the low-voltage terminal of the pair of negative electrode terminals and the low-voltage terminal of the pair of negative electrode charging terminals are arranged to be aligned in the second direction.

[0087] (Technical Idea 8) The relay unit according to any one of Technical Ideas 1 to 7, wherein the positive bus bar has positive wall surface facing portions (p1, p2, p3, p4, p5, p6) that face the wall surface of the case, the negative bus bar has negative wall surface facing portions (n1, n2, n3, n4, n5, n6, n7) that face the wall surface of the case, and the electrical component is interposed at least between the positive wall surface facing portions and the negative wall surface facing portions.

Claims

1. A positive electrode bus bar (20p) that forms a current path between the positive electrode side of the battery (3) and the inverter (4), a negative electrode bus bar (20n) that forms a current path between the negative electrode side of the battery and the inverter, relays (30p, 30n, 40p, 40n, 50) which are electromagnetic relays for switching the energization and interruption of the output current from the battery, a fuse (80) for interrupting the output current, a resistor (60) that serves as the electrical resistance of the output current, and an electrical component that is at least one of a current sensor (70) for detecting the magnitude of the output current, and a case (10) that houses the positive electrode bus bar, the negative electrode bus bar, and the electrical component inside, and a relay unit in which at least a part of the electrical component is interposed between the positive electrode bus bar and the negative electrode bus bar.

2. The electrical component includes the relay, and the relay includes a positive electrode relay (30p) having a pair of positive electrode terminals (31pH, 31pL) connected to the positive electrode bus bar and a negative electrode relay (30n) having a pair of negative electrode terminals (31nH, 31nL) connected to the negative electrode bus bar, and the relay unit according to claim 1, wherein both the positive electrode relay and the negative electrode relay are interposed between the positive electrode bus bar and the negative electrode bus bar.

3. The relay unit according to claim 2, wherein the positive electrode relay and the negative electrode relay are arranged such that the positive electrode terminal and the negative electrode terminal face opposite sides to each other.

4. The positive electrode relay has a positive electrode insulating plate (35p) which is an electrically insulating member arranged between the pair of positive electrode terminals, and the negative electrode relay has a negative electrode insulating plate (35n) which is an electrically insulating member arranged between the pair of negative electrode terminals, and the relay unit according to claim 2 or 3.

5. The electrical component includes a charging relay (40p, 40n) that switches the energization and interruption of the charging current flowing between the battery and the charging inlet (5). The charging relay includes a positive charging relay (40p) having a pair of positive charging terminals (41pH, 41pL) connected to the positive electrode bus bar, and a negative charging relay (40n) having a pair of negative charging terminals (41nH, 41nL) connected to the negative electrode bus bar. The power relay unit according to any one of claims 1 to 3, wherein both the positive charging relay and the negative charging relay are interposed between the positive electrode bus bar and the negative electrode bus bar.

6. The power relay unit according to claim 5, wherein the positive charging relay and the negative charging relay are arranged such that the positive charging terminals and the negative charging terminals face opposite sides of each other.

7. The electrical component includes a charging relay (40p, 40n) that switches the energization and interruption of the charging current flowing between the battery and the charging inlet (5). The charging relay includes a positive charging relay (40p) having a pair of positive charging terminals (41pH, 41pL) connected to the positive bus bar, and a negative charging relay (40n) having a pair of negative charging terminals (41nH, 41nL) connected to the negative bus bar. The positive charging relay and the negative charging relay are arranged such that the positive charging terminal and the negative charging terminal face opposite sides. The positive bus bar includes a positive inverter bus bar (21p) that forms a current path between the inverter and the positive relay, a positive charging bus bar (22p) that forms a current path between the charging inlet and the positive charging relay, and a positive battery bus bar (23p) that forms a current path between the battery and the positive relay. The negative bus bar includes a negative inverter bus bar (21n) that forms a current path between the inverter and the negative relay, a negative charging bus bar (22n) that forms a current path between the charging inlet and the negative charging relay, and a negative battery bus bar (23n) that forms a current path between the battery and the negative relay. The positive relay and the positive charging relay are arranged side by side in a predetermined first direction. The negative relay and the negative charging relay are arranged side by side in a predetermined second direction. The high-voltage side terminal of the pair of positive terminals and the high-voltage side terminal of the pair of positive charging terminals are arranged side by side in the first direction. The low-voltage side terminal of the pair of positive terminals and the low-voltage side terminal of the pair of positive charging terminals are arranged side by side in the first direction. The high-voltage side terminal of the pair of negative terminals and the high-voltage side terminal of the pair of negative charging terminals are arranged side by side in the second direction. The low-voltage side terminal of the pair of negative terminals and the low-voltage side terminal of the pair of negative charging terminals are arranged side by side in the second direction. The relay unit according to claim 3.

8. The positive electrode bus bar has a positive electrode wall surface facing portion (p1, p2, p3, p4, p5, p6) which is a portion facing the wall surface of the case, and the negative electrode bus bar has a negative electrode wall surface facing portion (n1, n2, n3, n4, n5, n6, n7) which is a portion facing the wall surface of the case. The relay unit according to any one of claims 1, 2, 3, and 7, wherein the electrical component is interposed between at least the positive electrode wall surface facing portion and the negative electrode wall surface facing portion.

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