JP2021146840A - Driving circuit unit and vehicle - Google Patents

Abstract

To inhibit reverse connection between a low voltage power source and a DC/DC converter.SOLUTION: A power control unit (PCU) 2 according to an embodiment is disposed below an engine hood of a vehicle and converts electric power from a high voltage battery to supply the electric power to a driving motor. The PCU 2 includes: a driving circuit 20 which performs electric power conversion; a DC/DC converter 21 which steps down a voltage from the high voltage battery; a low voltage battery 22 which is connected to the DC/DC converter 21 and outputs a voltage lower than the voltage of the high voltage battery; and a housing 23 which houses the driving circuit 20, the DC/DC converter 21, and the low voltage battery 22.SELECTED DRAWING: Figure 3

Description

The present invention relates to a drive circuit unit and a vehicle.

Vehicles such as hybrid vehicles and electric vehicles are equipped with a plurality of electrical devices such as an inverter for a vehicle drive motor, a DC / DC converter for a vehicle control power supply, and an inverter for driving an auxiliary machine.

For example, in Japanese Patent Application Laid-Open No. 2007-8403, a heat sink having a plurality of heat sink fins is provided on the back surface thereof, and a PDU including an inverter of a vehicle drive motor and a DC / DC converter for a vehicle control power supply are provided on the front surface side of the heat sink. Is installed. The DC / DC converter steps down the voltage generated by the vehicle drive motor to a specified voltage (for example, 12V) of a low-voltage power supply. The low voltage power supply is electrically connected to the DC / DC converter.

JP-A-2007-8403

By the way, when a user replaces a low-voltage power supply, there is a possibility that the connection between the low-voltage power supply and the DC / DC converter is mistakenly connected in the opposite direction to the regular connection (hereinafter, also simply referred to as "reverse connection"). ..
Therefore, there is room for improvement in suppressing the reverse connection between the low-voltage power supply and the DC / DC converter.

Therefore, an object of the present invention is to provide a drive circuit unit and a vehicle capable of suppressing reverse connection between a low voltage power supply and a DC / DC converter.

(1) The drive circuit unit (for example, PCU2 in the embodiment) according to one aspect of the present invention is arranged under the front hood of the vehicle (for example, the bonnet 16 in the embodiment) and has a power supply (for example, a high voltage in the embodiment). A drive circuit unit that converts power from the battery 6) and supplies it to a vehicle drive motor (for example, a traveling motor 4 in the embodiment) and performs power conversion (for example, the drive circuit 20 in the embodiment). And a DC / DC converter (for example, the DC / DC converter 21 in the embodiment) that lowers the voltage from the power supply, is connected to the DC / DC converter, and outputs a voltage lower than the voltage of the power supply. A low-voltage power supply (for example, the low-voltage battery 22 in the embodiment) and a housing for accommodating the drive circuit, the DC / DC converter, and the low-voltage power supply (for example, the housing 23 in the embodiment) are provided.

(2) In one aspect of the present invention, the DC / DC converter and the low-voltage power supply may be arranged at positions adjacent to each other inside the housing.

(3) In one aspect of the present invention, the low-voltage power supply may be arranged on the front side of the vehicle inside the housing.

(4) In one aspect of the present invention, the housing may have an opening (for example, an opening 35 in the embodiment) that exposes the low voltage power supply.

(5) In one aspect of the present invention, the housing may include a lid that can open and close the opening (for example, the lid 36 in the embodiment).

(6) In one aspect of the present invention, the housing may include fins (for example, fins 38 in the embodiment) arranged at a portion overlapping the low voltage power supply.

(7) In one aspect of the present invention, the housing may include a duct (for example, a duct 39 in the embodiment) that guides wind generated during vehicle travel toward the low-voltage power source.

(8) In one aspect of the present invention, the housing may be attached to a housing (for example, a housing 18 in the embodiment) that houses the vehicle driving motor.

(9) In one aspect of the present invention, the front end of the housing (for example, the front end P1 of the housing in the embodiment) is the front end of the housing accommodating the vehicle driving motor (for example, the front end P2 of the housing in the embodiment). ) May be located behind.

(10) In one aspect of the present invention, the front end of the low voltage power supply (for example, the front end P3 of the low voltage battery in the embodiment) is a component of the drive circuit arranged in the housing or the front end of a cooling unit (for example). , The front end P4 of the primary side capacitor in the embodiment or the front end P5) of the first joint may be arranged behind.

(11) In one aspect of the present invention, the drive circuit unit is a cooling unit (for example, a water jacket 250 in the embodiment) arranged adjacent to each of the low voltage power supply, the DC / DC converter, and the drive circuit. ) May be further provided.

(12) The vehicle according to one aspect of the present invention (for example, vehicle 1 in the embodiment) includes the above-mentioned drive circuit unit.

(13) In one aspect of the present invention, the vehicle may further include a notification unit (for example, a display unit 10 in the embodiment) for notifying that the voltage of the low voltage power supply has become equal to or lower than a threshold value.

(14) In one aspect of the present invention, the drive circuit unit may be arranged in a front room (for example, a front room 15 in the embodiment) at the front of the vehicle.

According to the aspect (1) above, the drive circuit unit includes a drive circuit, a DC / DC converter, and a housing for accommodating the low-voltage power supply, so that the low-voltage power supply is built in the drive circuit unit. Touching the power supply is suppressed. That is, it is suppressed that the user arbitrarily replaces the low voltage power supply. Therefore, it is possible to suppress the reverse connection between the low voltage power supply and the DC / DC converter.

According to the aspect (2) above, the DC / DC converter and the low-voltage power supply have the following effects when they are arranged at positions adjacent to each other inside the housing. Compared with the case where the DC / DC converter and the low-voltage power supply are arranged apart from each other inside the housing, the size of the housing can be reduced. In addition, the wiring for connecting the DC / DC converter and the low-voltage power supply can be shortened. In this case, since the wiring resistance becomes small, the loss can be reduced.

According to the aspect (3) above, the low-voltage power supply is arranged on the front side of the vehicle inside the housing, and thus has the following effects. Compared with the case where the low-voltage power supply is arranged on the rear side of the vehicle inside the housing, the maintainability is excellent.

According to the aspect (4) above, the housing has the following effects by having an opening for exposing the low voltage power supply. Since the low-voltage power supply can be touched through the opening, it is easy to maintain. In addition, since the low-voltage power supply can be blown through the opening, the low-voltage power supply can be cooled. For example, if the wind generated while the vehicle is running hits the low-voltage power supply through the opening, the low-voltage power supply can be cooled by natural air cooling.

According to the aspect (5) above, the housing has the following effects by providing a lid capable of opening and closing the opening. Compared with the case where the lid is not provided (when the opening of the housing is always open), it is possible to suppress the intrusion of foreign matter into the housing. For example, at a store, by opening the lid, the low-voltage power supply can be touched through the opening, which is excellent in maintainability.

According to the aspect (6) above, the housing is provided with fins arranged at a portion overlapping the low voltage power supply, thereby achieving the following effects. Since the surface area (heat transfer area) of the portion of the housing that overlaps with the low-voltage power supply increases, the low-voltage power supply can be cooled more effectively.

According to the aspect (7) above, the housing has the following effects by providing a duct for guiding the wind generated while the vehicle is running toward the low voltage power source. Since the wind generated while the vehicle is running is guided to the low-voltage power supply through the duct, the low-voltage power supply can be cooled by natural air cooling.

According to the aspect (8) above, the housing is attached to the housing accommodating the vehicle drive motor, thereby achieving the following effects. Since the drive circuit unit is integrated into the housing (mechanical and electrical integrated type), collision safety is improved while ensuring space under the front hood.

According to the aspect (9) above, the front end of the housing is arranged behind the front end of the housing accommodating the vehicle drive motor, so that the following effects can be obtained. Since the housing hits before the housing in the event of a collision from the front of the vehicle, the impact on the housing can be suppressed.

According to the aspect (10) above, the front end of the low-voltage power supply is arranged behind the front end of the drive circuit component or the cooling unit arranged in the housing, so that the following effects can be obtained. Since the components of the drive circuit or the cooling unit hit the low-voltage power supply before the low-voltage power supply in the event of a collision from the front of the vehicle, the impact on the low-voltage power supply can be suppressed.

According to the aspect (11) above, the drive circuit unit further includes a low-voltage power supply, a DC / DC converter, and a cooling unit arranged adjacent to each of the drive circuit, thereby achieving the following effects. The low-voltage power supply, DC / DC converter, and drive circuit can be cooled together. For example, by controlling the temperature of the low-voltage power supply, the life of the low-voltage power supply can be extended.

According to the above aspect (12), the vehicle can suppress the reverse connection between the low voltage power supply and the DC / DC converter by providing the above drive circuit unit.

According to the aspect (13) above, the vehicle further provides a notification unit for notifying that the voltage of the low voltage power supply is equal to or lower than the threshold value, thereby achieving the following effects. It is possible to inform the user when to replace the low-voltage power supply and prompt the dealer to replace the low-voltage power supply.

According to the aspect (14) above, the drive circuit unit is arranged in the front room in the front part of the vehicle, and thus has the following effects. Compared with the case where the drive circuit unit is arranged in the center of the vehicle, the maintainability is excellent. For example, at a dealer, the low-voltage power supply can be replaced by opening the housing with a special tool from the front room at the front of the vehicle.

The left side view of the vehicle which concerns on 1st Embodiment. Top view of the front part of the vehicle according to the first embodiment. Top view of the drive circuit unit according to the first embodiment. FIG. 3 is a sectional view taken along line IV-IV of FIG. The explanatory view of the electrical connection relation of the drive circuit unit which concerns on 1st Embodiment. The explanatory view of the notification timing at the time of leaving the vehicle which concerns on 1st Embodiment. The explanatory view of the notification timing at the time of traveling of the vehicle which concerns on 1st Embodiment. Top view of the drive circuit unit according to the first modification of the first embodiment. The left side view of the drive circuit unit which concerns on the 2nd modification of 1st Embodiment. The right side view of the mounted state of the drive circuit unit which concerns on 2nd Embodiment. Top view of the drive circuit unit according to the second embodiment. The bottom view of the drive circuit unit which concerns on 2nd Embodiment. The explanatory view of the cooling order of the drive circuit unit which concerns on 2nd Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the embodiment, a PCU (Power Control Unit) will be described as a drive circuit unit mounted on a hybrid vehicle (vehicle).

<First Embodiment>
<Whole vehicle>
As shown in FIG. 1, the vehicle 1 includes a PCU 2, an engine 3 (see FIG. 2), a traveling motor 4 (vehicle driving motor), a generator 5, a high-voltage battery 6 (power supply), and a fuse box 7 (see FIG. 2). , Cable 8, radiator 9, and display unit 10 (notification unit). The vehicle 1 uses an engine 3 and a traveling motor 4 as a traveling drive source.

For example, the traveling motor 4 is a three-phase AC brushless type. The traveling motor 4 generates power as a driving source for traveling of the vehicle 1 and supplies it to the wheels 11 (driving wheels) side. The traction motor 4 is driven by at least one of the electric power from the high voltage battery 6 and the electric power from the generator 5. The traveling motor 4 regenerates the vehicle 1 when braking, and supplies the regenerative power to the high-voltage battery 6. The regenerative power is supplied to the low voltage battery 22 (see FIG. 3, low voltage power supply). The traveling motor 4 may have a function of generating electricity based on the driving force of the engine 3. The traveling motor 4 may be of a direct current type or a brush type.

For example, the generator 5 (see FIG. 2) is a three-phase AC brushless type. The generator 5 generates electricity based on the driving force of the engine 3. The electric power generated by the generator 5 is supplied to the high-voltage battery 6, the traveling motor 4, or the low-voltage battery 22. The generator 5 can be used as a starter motor for the engine 3. The generator 5 may be of a direct current type or a brush type. The vehicle 1 may use the generator 5 as a traveling drive source.

The high voltage battery 6 includes a plurality of battery cells. The high voltage battery 6 is a power storage device (energy storage) capable of outputting a high voltage (several hundred volts). For example, as the high voltage battery 6, a lithium ion secondary battery, a nickel hydrogen secondary battery, or the like can be used. In addition, instead of or in addition to the high voltage battery 6, a power storage device such as a capacitor may be used.

The fuse box 7 (see FIG. 2) is an electrical connection box that houses electronic components such as fuses. The fuse box 7 is arranged between an auxiliary machine (not shown) and the PCU 2. The fuse is configured to blow when a large current exceeding the rating flows. Auxiliary equipment is a device that operates at a low voltage. For example, auxiliary equipment includes a navigation device, headlights, and the like (not shown).

The cable 8 is a power line connecting the high voltage battery 6 and the PCU 2.
The radiator 9 is a component that cools the refrigerant that cools the PCU2 and the like. The radiator 9 is arranged at the front of the vehicle. The radiator 9 is arranged in front of the PCU2.

The display unit 10 is arranged in the vehicle interior 12. The display unit 10 is arranged in front of the seat 13. The display unit 10 is electrically connected to the PCU 2. The display unit 10 notifies that the power supply of the low-voltage battery 22 has become equal to or lower than the threshold value. For example, the display unit 10 is a charge lamp provided on the meter panel.

<PCU2>
The PCU 2 converts the electric power from the high voltage battery 6 and supplies it to the traveling motor 4. The PCU 2 converts the generated power of the generator 5 and the generated power (regenerative power) of the traveling motor 4 to charge the high-voltage battery 6. As shown in FIG. 3, the PCU 2 includes a drive circuit 20, a DC / DC converter 21, a low-voltage battery 22, and a housing 23.

<Drive circuit 20>
The drive circuit 20 includes an inverter 25 and an ECU 26 (Electronic Control Unit).
The inverter 25 converts the direct current from the high-voltage battery 6 into an alternating current and supplies it to the traveling motor 4. The inverter 25 converts the alternating current from the traveling motor 4 into a direct current and supplies it to the high voltage battery 6. The inverter 25 converts the alternating current from the generator 5 into a direct current and supplies it to the high-voltage battery 6 and the traveling motor 4. When the generator 5 is used as a traveling drive source, the inverter 25 converts the direct current from the high-voltage battery 6 into an alternating current and supplies it to the generator 5.

The ECU 26 is a control device that controls each part of the PCU 2. The ECU 26 includes an input / output unit, a calculation unit, and a storage unit (not shown). The input / output unit inputs / outputs signals to / from each unit of the vehicle 1 via a signal line. The input / output unit includes an A / D conversion circuit (not shown) that converts the input analog signal into a digital signal.

The arithmetic unit includes a central processing unit (CPU). The arithmetic unit operates by executing a program stored in the storage unit. Some of the functions executed by the arithmetic unit can also be realized by using a logic IC (Integrated Circuit). The program may be supplied from the outside via a wireless communication device such as a mobile phone or a smartphone. The arithmetic unit may also configure a part of the program with hardware (circuit parts).

The storage unit stores programs and data used by the calculation unit. The storage unit includes a random access memory (hereinafter referred to as "RAM"). As the RAM, a volatile memory such as a register and a non-volatile memory such as a flash memory can be used. The storage unit may include a read-only memory (ROM) in addition to the RAM.

<DC / DC converter 21>
The DC / DC converter 21 is a buck-boost type converter. The DC / DC converter 21 boosts the output voltage of the high-voltage battery 6 and outputs it to the traveling motor 4. The DC / DC converter 21 steps down the output voltage of the generator 5 or the output voltage of the traveling motor 4 and supplies the high voltage battery 6. The DC / DC converter 21 steps down the output voltage of the high-voltage battery 6 and supplies it to the low-voltage battery 22. The DC / DC converter 21 is electrically connected to each of the drive circuit 20 and the low-voltage battery 22 (see FIG. 5).

<Low voltage battery 22>
The low voltage battery 22 is connected to the DC / DC converter 21. The low voltage battery 22 outputs a voltage lower than that of the high voltage battery 6. The low-voltage battery 22 is a low-voltage power source that supplies low-voltage (for example, 12V) power to an auxiliary device (not shown). For example, as the low voltage battery 22, a lead battery, a lithium battery, or the like can be used.

<Case 23>
The housing 23 houses the drive circuit 20, the DC / DC converter 21, and the low-voltage battery 22. The housing 23 can be disassembled by a special tool (the low-voltage battery 22 and the like inside the housing 23 can be taken out). The housing 23 is a rectangular parallelepiped box having a length in the front-rear direction of the vehicle. The housing 23 includes a high-voltage side terminal 31 and a low-voltage take-out side terminal 32 (see FIG. 5). As shown in FIG. 5, the high voltage side terminal 31 is provided on one side surface of the housing 23. The low voltage take-out side terminal 32 is provided on the other side surface of the housing 23 (the surface opposite to the high voltage side terminal 31 side).

The high voltage side terminal 31 is electrically connected to each of the DC / DC converter 21 and the drive circuit 20. One end of the cable 8 (see FIG. 1) is connected to the high voltage side terminal 31. The other end of the cable 8 is connected to the high voltage battery 6 (see FIG. 1).

The low-voltage extraction side terminal 32 is electrically connected to each of the DC / DC converter 21 and the low-voltage battery 22. One end of a low voltage cable (not shown) is connected to the low voltage take-out side terminal 32. The other end of the low voltage cable is connected to the fuse box 7 (see FIG. 2, auxiliary equipment side).

FIG. 4 is a sectional view taken along line IV-IV of FIG. In FIG. 4, only the housing 23 is shown by a cross-sectional hatch.
As shown in FIG. 4, the housing 23 has an opening 35 that exposes the low voltage battery 22. The opening 35 has a rectangular shape having a length in the front-rear direction of the vehicle in a plan view (see FIG. 3). The opening 35 has an outer shape smaller than that of the low-voltage battery 22 in a plan view (see FIG. 3).

The housing 23 includes a lid 36 capable of opening and closing the opening 35. The lid 36 has a rectangular shape having a length in the front-rear direction of the vehicle in a plan view (see FIG. 3). The lid 36 has an outer shape with an opening of 35 or more in a plan view (see FIG. 3). The lid 36 is rotatable around a shaft (for example, a hinge shaft) (not shown). In the closed state, the lid 36 is restricted from rotating around the shaft portion by a locking portion (not shown).

<Arrangement of each part of the vehicle>
As shown in FIG. 1, the engine 3 (see FIG. 2), the traveling motor 4, the generator 5 (see FIG. 2), the PCU 2 and the fuse box 7 (see FIG. 2) are arranged in the front room 15 at the front of the vehicle. There is. The front room 15 includes an engine room in which the engine 3 is arranged and a motor room in which the traveling motor 4 is arranged.

The front room 15 is provided between the vehicle interior 12, the bonnet 16 (front hood), and the front frame 17. The front room 15 is connected to a main frame (not shown). Reference numeral 18 in the drawing indicates a housing for accommodating the traveling motor 4 and the generator 5. The housing 18 is arranged on the left side of the front part of the vehicle. The PCU 2 is arranged below the bonnet 16. The PCU 2 is fixed to the upper surface of the housing 18. That is, the housing 23 of the PCU 2 (see FIG. 3) is attached to the housing 18. The PCU2 is a so-called mechanical / electrical integrated type that is directly mounted (integrated) on the housing 18.

Reference numeral 19 in the figure indicates a floor that supports the seat 13 in the passenger compartment 12 from below. The high voltage battery 6 is located below the floor 19. The high voltage battery 6 is supported by a mainframe (not shown).

<Arrangement of components of PCU2>
As shown in FIG. 3, the drive circuit 20, the DC / DC converter 21, and the low-voltage battery 22 are arranged inside the housing 23. The DC / DC converter 21 and the low-voltage battery 22 are arranged in front of the drive circuit 20. The DC / DC converter 21 and the low-voltage battery 22 are arranged adjacent to each other in the vehicle width direction. The DC / DC converter 21 is arranged on the right side inside the housing 23. The low-voltage battery 22 is arranged on the left side inside the housing 23.

The terminal portions 28, 29 (positive electrode terminal 28 and negative electrode terminal 29) of the low-voltage battery 22 are arranged at positions overlapping the opening 35 in a plan view. The positive electrode terminal 28 and the negative electrode terminal 29 are arranged at intervals in the front-rear direction of the vehicle. The terminals 28 and 29 of the low voltage battery 22 are exposed from the opening 35 when the lid 36 is open. When the lid 36 is open, the terminals 28 and 29 of the low voltage battery 22 can be accessed from above.

<Notification timing of display unit 10>
FIG. 6 is an explanatory diagram of the notification timing when the vehicle 1 is left unattended. FIG. 7 is an explanatory diagram of the notification timing when the vehicle 1 is traveling. In FIGS. 6 and 7, the horizontal axis represents time, and the vertical axis represents vehicle operating energy, the capacity of the high-voltage battery 6 (SOC), and the capacity of the low-voltage battery 22 (SOC). Reference numeral G1 is a graph of vehicle operating energy, reference numeral G2 is a graph of the capacity of the high-voltage battery 6, and reference numeral G3 is a graph of the capacity of the low-voltage battery 22. In the graph G3 of the capacity of the low-voltage battery 22, the A threshold is the threshold for requesting charging of the low-voltage battery 22, and the O threshold is the threshold at which the low-voltage system including the low-voltage battery 22 falls, the ECU 26 stops, and the vehicle 1 also stops ( The low-voltage battery 22 is in a raised state), and the M threshold indicates a threshold for detecting deterioration of the low-voltage battery 22, respectively.

FIG. 6 is an example of a system in which the DC / DC converter 21 is started by high voltage energization under a control range in which the engine 3 is not started in the hybrid vehicle 1 to charge the low voltage battery 22.
The low-voltage battery 22 alternately repeats discharging (leaving discharge) and charging (leaving charging) with the passage of time (leaving time). The downward-sloping direction in the figure indicates the discharged state, and the upward-sloping direction indicates the charged state. For example, in the low-voltage battery 22, discharge and charge are controlled (charge / discharge control) from the time when the vehicle 1 is left to the point where the vehicle can be started at least as the vehicle operating energy. For example, the low-voltage battery 22 stops charging when the capacity of the high-voltage battery 6 becomes equal to or less than the B threshold value or when the vehicle operating energy becomes equal to or less than the D threshold value, whichever comes first. Reference numerals W1 and W2 in the figure indicate a range in which the low-voltage battery 22 stops charging. For example, the display unit 10 lights up when the capacity of the low-voltage battery 22 becomes equal to or less than the M threshold value, thereby informing the user that the low-voltage battery 22 is about to be replaced.

FIG. 7 shows an example of control in the state of the vehicle 1 that can be charged from the outside.
In this case, normally, the high-voltage battery 6 is charged and the low-voltage battery 22 is also charged at the same time. The low-voltage battery 22 alternately repeats discharging (running discharge) and charging (running charge) with the passage of time (running time). The downward-sloping direction in the figure indicates the discharged state, and the upward-sloping direction indicates the charged state. For example, the display unit 10 lights up when the capacity of the low-voltage battery 22 becomes equal to or less than the M threshold value, thereby informing the user that the low-voltage battery 22 is about to be replaced.
By the above-mentioned control, the user can recognize the replacement time of the low voltage battery 22 when the vehicle 1 is left unattended and when the vehicle 1 is running.

As described above, the PCU2 of the above embodiment is a PCU2 that is arranged under the bonnet 16 of the vehicle, converts the power from the high voltage battery 6 and supplies it to the traveling motor 4, and is a drive circuit that performs power conversion. 20, a DC / DC converter 21 that lowers the voltage from the high-voltage battery 6, and a low-voltage battery 22 that is connected to the DC / DC converter 21 and outputs a voltage lower than the voltage of the high-voltage battery 6. It includes a drive circuit 20, a DC / DC converter 21, and a housing 23 that houses a low-voltage battery 22.
According to this configuration, the PCU2 includes the drive circuit 20, the DC / DC converter 21, and the housing 23 that houses the low-voltage battery 22, so that the low-voltage battery 22 is built into the PCU2, so that the user can lower the voltage. Touching the battery 22 is suppressed. That is, it is suppressed that the user arbitrarily replaces the low voltage battery 22. Therefore, the reverse connection between the low voltage battery 22 and the DC / DC converter 21 can be suppressed.
For example, when replacing the low voltage battery 22, the user brings the PCU 2 to a store. The store has a special tool that can open the housing 23. At the store, the low-voltage battery 22 can be replaced by opening the housing 23 with a special tool.
For example, since the power failure of the low-voltage battery 22 due to an impact does not occur, the backup power source for discharging the internal capacitor of the PCU can be reduced, and the cost can be reduced.

In the above embodiment, the DC / DC converter 21 and the low-voltage battery 22 are arranged at positions adjacent to each other inside the housing 23, thereby achieving the following effects.
Compared with the case where the DC / DC converter 21 and the low-voltage battery 22 are arranged apart from each other inside the housing 23, the size of the housing 23 can be reduced. In addition, the wiring for connecting the DC / DC converter 21 and the low-voltage battery 22 can be shortened. In this case, since the wiring resistance becomes small, the loss can be reduced. Moreover, since the impedance of the wiring becomes small, noise caused by this impedance can be suppressed. In addition, the weight and cost can be reduced by the amount of shortened wiring.

In the above embodiment, the low-voltage battery 22 is arranged on the front side of the vehicle inside the housing 23, and thus has the following effects.
Compared with the case where the low-voltage battery 22 is arranged on the rear side of the vehicle inside the housing 23, the maintainability is excellent. For example, at a store, the low-voltage battery 22 can be replaced by opening the housing 23 with a special tool from the front of the vehicle.

In the above embodiment, the housing 23 has the following effects by having an opening 35 that exposes the low voltage battery 22. Since the low-voltage battery 22 can be touched through the opening 35, it is excellent in maintainability. In addition, since the low voltage battery 22 can be blown through the opening 35, the low voltage battery 22 can be cooled. For example, if the wind generated while the vehicle is running hits the low-voltage battery 22 through the opening 35, the low-voltage battery 22 can be cooled by natural air cooling.

In the above embodiment, the housing 23 is provided with a lid 36 capable of opening and closing the opening 35, thereby achieving the following effects. Compared with the case where the lid 36 is not provided (when the opening 35 of the housing 23 is always open), it is possible to suppress the intrusion of foreign matter into the housing 23. For example, at a store, the low-voltage battery 22 can be touched through the opening 35 by opening the lid 36, which is excellent in maintainability.

In the above embodiment, the housing 23 is attached to the housing 18 accommodating the traveling motor 4 to achieve the following effects. Since the PCU 2 is integrated with the housing 18 (mechanical and electrical integrated type), collision safety is improved while securing a space under the bonnet 16.

In the above embodiment, the vehicle 1 further includes a display unit 10 for notifying that the voltage of the low voltage battery 22 is equal to or lower than the threshold value, thereby achieving the following effects.
It is possible to notify the user when to replace the low-voltage battery 22 and prompt the dealer to replace the low-voltage battery 22.

In the above embodiment, the PCU 2 is arranged in the front room 15 at the front of the vehicle, and thus has the following effects.
Compared with the case where the PCU2 is arranged in the center of the vehicle, the maintainability is excellent. For example, at a dealer, the low-voltage battery 22 can be replaced by opening the housing 23 from the front room 15 at the front of the vehicle with a special tool.

<Modification example>
In the above-described embodiment, the example in which the vehicle 1 is a hybrid vehicle has been described, but the present invention is not limited to this. For example, the vehicle 1 may be an electric vehicle (electric vehicle) that does not have an engine 3. For example, the vehicle 1 may include a plurality of traveling motors 4 and a plurality of generators 5.

In the above-described embodiment, an example in which the high-voltage battery 6 is used as the power source for supplying electric power to the traveling motor 4 via the PCU 2 has been described, but the present invention is not limited to this. For example, it is possible to use the generator 5 as a main power source (use as a so-called range extender, which is a system composed of a small generator mounted for the purpose of extending the mileage of an electric vehicle).

In the above-described embodiment, the DC / DC converter 21 and the low-voltage battery 22 have been described with reference to an example in which they are arranged adjacent to each other inside the housing 23, but the present invention is not limited to this. For example, the DC / DC converter 21 and the low-voltage battery 22 may be arranged apart from each other inside the housing 23.

In the above embodiment, the low-voltage battery 22 has been described with reference to an example in which the low-voltage battery 22 is arranged on the front side of the vehicle inside the housing 23, but the present invention is not limited to this. For example, the low-voltage battery 22 may be arranged on the rear side of the vehicle inside the housing 23.

In the above embodiment, the housing 23 has been described with reference to an example having an opening 35 for exposing the low voltage battery 22, but the present invention is not limited to this. For example, the housing 23 may not have an opening 35 that exposes the low voltage battery 22. For example, the inside of the housing 23 may be hermetically sealed.

In the above embodiment, the housing 23 has been described with reference to an example in which the lid 36 capable of opening and closing the opening 35 is provided, but the present invention is not limited to this. For example, the housing 23 does not have to have the lid 36. In this case, since the low-voltage battery 22 can be blown through the opening 35 at all times, the low-voltage battery 22 can be cooled.

In the above embodiment, the vehicle 1 has been described with reference to an example in which the charge lamp is provided as the display unit 10 for notifying that the voltage of the low voltage battery 22 is equal to or lower than the threshold value, but the present invention is not limited to this. For example, the display unit 10 may be a display area (display unit for warning messages, etc.) provided on the meter panel. For example, the notification unit is not limited to the display unit 10, and may be a speaker that emits a warning sound. The notification unit can adopt various configurations as long as it can notify the user when to replace the low-voltage battery 22. Further, the vehicle 1 does not have to have a notification unit.

In the above embodiment, the PCU 2 has been described with reference to an example in which the PCU 2 is arranged in the front room 15 at the front of the vehicle, but the present invention is not limited to this. For example, the PCU 2 may be arranged in the center of the vehicle (area other than the front room 15 of the vehicle 1).

For example, as shown in FIG. 8, the housing 23 may include fins 38 arranged at a portion overlapping the low voltage battery 22. In this case, since the surface area (heat transfer area) of the portion of the housing 23 that overlaps with the low-voltage battery 22 increases, the low-voltage battery 22 can be cooled more effectively.
In the example of the figure, a plurality of fins 38 are provided on the upper surface of the housing 23 that overlaps the low-voltage battery 22 in a plan view and on the left side surface of the housing 23 that overlaps the low-voltage battery 22 in a side view. The fin 38 has an outer shape extending in the front-rear direction of the vehicle.

For example, the housing 23 may include a duct 39 that guides the wind generated while the vehicle is running toward the low voltage power source. In this case, since the wind generated while the vehicle is running is guided to the low voltage battery 22 through the duct 39, the low voltage power source can be cooled by natural air cooling.
In the example of the figure, the duct 39 is provided on the front surface of the housing 23 which overlaps with the low voltage battery 22 in front view. The duct 39 opens in the front-rear direction of the vehicle.

In the above embodiment, the DC / DC converter 21 and the low-voltage battery 22 have been described with reference to an example of a so-called horizontal installation type in which the DC / DC converter 21 and the low-voltage battery 22 are arranged adjacent to each other in the vehicle width direction, but the present invention is not limited to this. For example, as shown in FIG. 9, the DC / DC converter 21 and the low-voltage battery 22 may be of a so-called vertical type (vertical type) arranged at positions adjacent to each other in the vertical direction of the vehicle. In the example of the figure, the DC / DC converter 21 is arranged on the upper side (the side of the terminals 28 and 29) of the low voltage battery 22. For example, when the DC / DC converter 21 and the low-voltage battery 22 are connected to each other at their respective terminals and do not have wiring, it is not necessary to set a resistor (correction resistor) for correcting the resistance of the wiring.

<Second embodiment>
As shown in FIG. 10, the PCU 202 includes a drive circuit 220, a DC / DC converter 21, a junction board 244, a low voltage battery 22, a water jacket 250 (cooling unit), and a housing 223. In the second embodiment, the same configurations as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

The drive circuit 220 includes an ECU 26 (Electronic Control Unit), an IPM240 (Intelligent Power Module), a primary side capacitor 241 and a reactor 242, and a secondary side capacitor 243.
For example, the IPM 240 is a semiconductor device including a power device (not shown) such as a power MOSFET for controlling electric power and an insulated gate bipolar transistor (IGBT). The IPM 240 is arranged at a position overlapping the ECU 26 in a plan view (see FIG. 12). The front end of the ECU 26 is arranged behind the front end of the IPM 240.

The primary side capacitor 241 and the reactor 242 and the secondary side capacitor 243 are arranged in this order from the front side of the vehicle. The primary side capacitor 241 and the reactor 242 and the secondary side capacitor 243 are arranged on the right side of the IPM 240 (see FIG. 12). The reactor 242 is arranged at a position adjacent to each of the primary side capacitor 241 and the secondary side capacitor 243. The reactor 242 is electrically connected to each of the primary side capacitor 241 and the secondary side capacitor 243. The secondary side capacitor 243 is arranged at a position adjacent to the DC / DC converter 21.

The junction board 244 is arranged between the DC / DC converter 21 and the low voltage battery 22 (see FIG. 11). The junction board 244 is arranged at a position adjacent to each of the DC / DC converter 21 and the low voltage battery 22. The junction board 244 is electrically connected to each of the DC / DC converter 21 and the low voltage battery 22.

The water jacket 250 includes a cooling main body 251 capable of flowing cooling water, and cooling joints 252A and 252B protruding forward from the cooling main body 251. The water jacket 250 cools the components of the PCU 202 with the cooling water circulating in the cooling body 251. The water jacket 250 is arranged adjacent to each of the low voltage battery 22, the DC / DC converter 21, and the drive circuit 220.

The cooling body 251 is arranged between the low voltage battery 22 and the IPM 240. The cooling main body 251 is arranged between the lower front wall of the housing 223 (the front wall of the first accommodating portion 223A) and the DC / DC converter 21. The low voltage battery 22 is arranged on the upper surface of the cooling main body 251. The DC / DC converter 21 is arranged on the rear surface of the cooling body 251. The drive circuit 220 is arranged on the lower surface of the cooling body 251.

The cooling joints 252A and 252B project forward from the housing 223. For example, the cooling joints 252A and 252B are pipes for putting the cooling water into the cooling main body 251 and discharging the cooling water to the outside of the cooling main body 251. For example, the cooling water is flowed in order from the component having the lower control temperature (for example, the low voltage battery 22) in the component of the PCU 202.

Here, the cooling joint 252A for putting the cooling water into the cooling main body 251 is referred to as "first joint 252A", and the cooling joint 252B for discharging the cooling water to the outside of the cooling main body 251 is referred to as "second joint 252B".
As shown in FIG. 13, for example, the cooling water from the first joint 252A flows along the lower surface of the low voltage battery 22 toward the DC / DC converter 21 as shown by an arrow V1. After that, the cooling water flows from the DC / DC converter 21 toward the second joint 252B along the upper surface of the drive circuit 220 as shown by the arrow V2. That is, the cooling water flows in the order of the low voltage battery 22, the DC / DC converter 21, and the drive circuit 220.

The housing 223 houses the drive circuit 220, the DC / DC converter 21, the junction board 244, the low voltage battery 22, and the cooling body 251. The housing 223 can be disassembled by a special tool (the low-voltage battery 22 and the like inside the housing 223 can be taken out). The housing 223 includes a first accommodating portion 223A accommodating the drive circuit 220 and the cooling main body 251, a second accommodating portion 223B accommodating the junction board 244 and the low-voltage battery 22, and a third accommodating the DC / DC converter 21. It is provided with a storage unit 223C.

The first accommodating portion 223A is a first floor portion (lower portion) of the housing 223. The second accommodating portion 223B is connected to the upper part of the first accommodating portion 223A. The second accommodating portion 223B is a second floor portion (upper stage portion) of the housing 223. The front end of the first accommodating portion 223A is arranged in front of the front end of the second accommodating portion 223B.

As shown in FIG. 10, the housing 223 is attached to the housing 218. The housing 223 is fixed to the upper surface of the housing 218. The PCU 202 is a so-called mechanical / electrical integrated type that is directly mounted (integrated) on the housing 218. For example, housing 218 is a motor housing. Housing 218 houses a traveling motor and transmission (not shown). The housing 218 bulges forward from the housing 223.

In the mounted state of the PCU202, the components of the PCU202 such as the housing 223 are inclined forward and downward in a side view. The front end P1 of the housing 223 is arranged behind the front end P2 of the housing 218. In FIG. 10, reference numeral L1 indicates a first virtual vertical line passing through the front end P1 of the housing 223, and reference numeral L2 indicates a second virtual vertical line passing through the front end P2 of the housing 218. The first virtual vertical line L1 is arranged behind the second virtual vertical line L2.

The front end P3 of the low-voltage battery 22 is arranged behind the components of the drive circuit 220 arranged in the housing 223 or the front ends P4 and P5 of the water jacket 250. Specifically, the front end P3 of the low-voltage battery 22 is arranged behind the front end P4 of the primary side capacitor 241 constituting the drive circuit 220. Further, the front end P3 of the low voltage battery 22 is arranged behind the front end P5 of the first joint 252A of the water jacket 250.
Further, the front end P3 of the low voltage battery 22 is arranged behind the front end P1 of the housing 223 (first accommodating portion 223A).

In the second embodiment, since the low voltage battery 22 is built in the PCU 202, the same effect as that of the first embodiment is obtained. For example, since the power failure of the low-voltage battery 22 due to an impact does not occur, the backup power source for discharging the internal capacitor of the PCU can be reduced, and the cost can be reduced.

In the second embodiment, the housing 223 is attached to the housing 218 that houses the traveling motor, and thus has the following effects. Since the PCU 202 is integrated with the housing 218 (mechanical and electrical integrated type), collision safety is improved while securing a space under the bonnet.

In the second embodiment, the front end P1 of the housing 223 is arranged behind the front end P2 of the housing 218 accommodating the traveling motor, thereby achieving the following effects. Since the housing 218 hits before the housing 223 at the time of a collision from the front of the vehicle, the impact on the housing 223 can be suppressed.

In the second embodiment, the front end P3 of the low-voltage battery 22 is arranged behind the components of the drive circuit 220 arranged in the housing 223 or the front ends P4 and P5 of the water jacket 250. It works. Since the component of the drive circuit 220 or the water jacket 250 hits before the low-voltage battery 22 in the event of a collision from the front of the vehicle, the impact on the low-voltage battery 22 can be suppressed.

In the second embodiment, the PCU 202 further includes a water jacket 250 arranged adjacent to each of the low voltage battery 22, the DC / DC converter 21, and the drive circuit 220, thereby achieving the following effects. The low-voltage battery 22, the DC / DC converter 21, and the drive circuit 220 can be cooled together. For example, by controlling the temperature of the low-voltage battery 22, the life of the low-voltage battery 22 can be extended.

In the second embodiment, the PCU 202 has been described with reference to an example in which the water jacket 250 is provided at a position adjacent to each of the low voltage battery 22, the DC / DC converter 21, and the drive circuit 220, but the present invention is limited to this. No. For example, the PCU 202 may include a cooling unit other than the water jacket 250 such as a heat sink. For example, the PCU 202 may not be provided with a cooling unit.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and configurations can be added, omitted, replaced, and other changes can be made without departing from the spirit of the present invention. Yes, it is also possible to appropriately combine the above-mentioned modification examples.

1 ... Vehicle 2,202 ... PCU (Drive circuit unit)
4 ... Travel motor (vehicle drive motor)
6 ... High voltage battery (power supply)
10 ... Display unit (notification unit)
15 ... Front room 16 ... Bonnet (front hood)
18,218 ... Housing 20,220 ... Drive circuit 21 ... DC / DC converter 22 ... Low voltage battery (low voltage power supply)
23, 223 ... Housing 35 ... Opening 36 ... Lid 38 ... Fin 39 ... Duct 250 ... Water jacket (cooling part)
P1 ... Front end of housing P2 ... Front end of housing P3 ... Front end of low-voltage battery (front end of low-voltage power supply)
P4 ... Front end of primary capacitor (front end of drive circuit components)
P5 ... Front end of the first joint (front end of the cooling unit)

Claims (14)

It is a drive circuit unit that is placed under the front hood of the vehicle, converts the electric power from the power source, and supplies it to the vehicle drive motor.
The drive circuit that performs power conversion and
A DC / DC converter that steps down the voltage from the power supply,
A low-voltage power supply that is connected to the DC / DC converter and outputs a voltage lower than the voltage of the power supply.
A drive circuit unit including the drive circuit, the DC / DC converter, and a housing for accommodating the low-voltage power supply. The drive circuit unit according to claim 1, wherein the DC / DC converter and the low-voltage power supply are arranged at positions adjacent to each other inside the housing. The drive circuit unit according to claim 1 or 2, wherein the low-voltage power supply is arranged on the front side of the vehicle inside the housing. The drive circuit unit according to any one of claims 1 to 3, wherein the housing has an opening for exposing the low voltage power supply. The drive circuit unit according to claim 4, wherein the housing includes a lid capable of opening and closing the opening. The drive circuit unit according to any one of claims 1 to 5, wherein the housing includes fins arranged at a portion overlapping the low-voltage power supply. The drive circuit unit according to any one of claims 1 to 6, wherein the housing includes a duct that guides wind generated during vehicle travel toward the low-voltage power supply. The drive circuit unit according to any one of claims 1 to 7, wherein the housing is attached to a housing for accommodating the vehicle drive motor. The drive circuit unit according to any one of claims 1 to 8, wherein the front end of the housing is arranged behind the front end of the housing accommodating the vehicle drive motor. The method according to any one of claims 1 to 9, wherein the front end of the low-voltage power supply is arranged behind the front end of the drive circuit component or the cooling unit arranged in the housing. Drive circuit unit. The drive circuit unit according to any one of claims 1 to 10, further comprising a cooling unit arranged at a position adjacent to each of the low-voltage power supply, the DC / DC converter, and the drive circuit. A vehicle comprising the drive circuit unit according to any one of claims 1 to 11. The vehicle according to claim 12, further comprising a notification unit for notifying that the voltage of the low-voltage power supply is equal to or lower than the threshold value. The vehicle according to claim 12 or 13, wherein the drive circuit unit is arranged in a front room at the front of the vehicle.

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