Vehicle drive device

Abstract

To realize a vehicle drive device capable of efficiently performing heat exchange between a heat medium and oil in both high and low oil temperature environments.SOLUTION: A vehicle drive device comprises: a first heat exchanger 31 configured to have a larger amount of energy available for heat exchange than a second heat exchanger 32 when an oil temperature is within a first temperature range; the second heat exchanger 32 configured to have a larger amount of energy available for the heat exchange than the first heat exchanger 31 when the oil temperature is within a second temperature range which is lower than the first temperature range; and a switch valve V9. When the oil temperature is equal to or higher than a switching temperature set between a lower limit of the first temperature range and an upper limit of the second temperature range, the switch valve V9 switches an oil circuit 55 so that oil OL passes through the first heat exchanger 31 without passing through the second heat exchanger 32. When the oil temperature is less than the switching temperature, the switch valve switches the oil circuit 55 so that the oil OL passes through the second heat exchanger 32 without passing through the first heat exchanger 31.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to a vehicle drive system including a power transmission mechanism and a heat exchanger. [Background technology]

[0002] A vehicle drive device including a power transmission mechanism and a heat exchanger is known. JP 2021-124185 A (Patent Document 1) describes a vehicle drive device including a power transmission mechanism (1) and a cooling chamber (17) that functions as a heat exchanger. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-124185 Summary of the Invention [Problem to be solved by the invention]

[0004] In the vehicle drive device disclosed in the above document, the oil (OL) passing through the first oil feed path (P1) and the second oil feed path (P2) exchanges heat with a heat medium (cooling water Q) when it flows through a heat exchanger (cooling chamber 17). In this vehicle drive device, in order to improve the efficiency of cooling the oil (OL) with the heat medium (Q), the second oil feed path (P2) is a labyrinth path having two or more turn-back structures in the heat exchanger (17). However, in a low-temperature environment where the viscosity of the oil is high, the discharge speed of the oil from the heat exchanger (17) becomes too slow, which may cause a problem of reducing the efficiency of heat exchange between the heat medium (Q) and the oil (OL).

[0005] Therefore, it is desirable to realize a vehicle drive device that can efficiently exchange heat between a heat medium and oil both in environments where the oil temperature is high and in environments where the oil temperature is low. [Means for solving the problem]

[0006] A vehicle drive device according to the present disclosure is a vehicle drive device including a rotating electric machine, an output member drivingly connected to a wheel, a power transmission mechanism for transmitting power between the rotating electric machine and the output member, a case including the rotating electric machine, the power transmission mechanism, and an accommodation chamber for accommodating oil, a heat medium circuit through which a heat medium circulates, and an oil circuit through which the oil circulates, and further including a first heat exchanger for exchanging heat between the heat medium and the oil, a second heat exchanger for exchanging heat between the heat medium and the oil, and a switching mechanism for switching the oil circuit, and the first heat exchanger is configured to switch between the second heat exchanger and the oil when an oil temperature, which is a temperature of the oil, is within a predetermined first temperature range. the first heat exchanger is configured to have a larger amount of heat exchangeable energy than the first heat exchanger when the oil temperature is in a second temperature range lower than the first temperature range, and the switching mechanism switches the oil circuit so that the oil passes through the first heat exchanger without passing through the second heat exchanger when the oil temperature is equal to or higher than a switching temperature set between a lower limit of the first temperature range and an upper limit of the second temperature range, and switches the oil circuit so that the oil passes through the second heat exchanger without passing through the first heat exchanger when the oil temperature is lower than the switching temperature.

[0007] According to this configuration, heat exchange can be performed using either the first heat exchanger or the second heat exchanger, whichever has the greater amount of heat exchangeable energy depending on the oil temperature at each time. Therefore, heat exchange between the heat medium and the oil can be efficiently performed both when the oil temperature is higher and lower than the switching temperature. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing a vehicle drive device according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a schematic exploded perspective view of the vehicle drive device of FIG. 1; [Diagram 3] 2 is a side view of the vehicle drive device of FIG. 1; [Figure 4] 2 is a rear view of the vehicle drive device of FIG. 1; [Diagram 5] 2 is a schematic control block diagram of the vehicle drive device of FIG. 1; [Figure 6] FIG. 3 is a perspective view showing the arrangement of the cooling units in FIG. 2; [Figure 7] FIG. 3 is a diagram showing a schematic diagram of a first heat transfer medium circuit including the cooling unit of FIG. 2; [Figure 8] 8 is a schematic cross-sectional view of the first heat exchanger and the second heat exchanger of FIG. 7 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the vehicle drive device 10 will be described with reference to the drawings. The vehicle drive device 10 of this embodiment appropriately configures a thermal management system in a vehicle with the vehicle drive device 10 as a core while suppressing an increase in size. For example, in A-segment vehicles in Europe and small vehicles such as minicars in Japan, it is required to improve mounting efficiency by making the vehicle drive device 10 and other on-board components as small and light as possible. For example, it is preferable to shorten the length of connecting components such as wiring and piping by arranging on-board components close to each other, or to reduce wiring and piping by integrating different devices.

[0010] In addition, the heat medium for cooling the heat generating devices in the vehicle, such as the driving force source of the wheels, is exhausted by a radiator, and the radiator is generally arranged at the very front of the vehicle to exhaust heat by the wind while the vehicle is running. In addition, in small cars such as A-segment cars, in order to secure the interior space for the passengers, the front wheels are often driven, and the driving force source of the wheels is also arranged at the front of the vehicle. In addition, in vehicles equipped with an on-board air conditioner that performs cooling and heating, the on-board air conditioner, as well as many parts of the flow path through which the heat medium used in the on-board air conditioner flows, and functional parts that perform heat exchange are also arranged at the front of the vehicle. In particular, with regard to heating, in conventional vehicles in which an internal combustion engine was used as the driving force source of the wheels, it was easy to use the internal combustion engine as a heat source, but in vehicles that do not have an internal combustion engine, such as electric vehicles, there is no such heat source, and a heat pump system is exclusively used for heating, and the number of mounted parts tends to increase compared to a system that uses the exhaust heat of the internal combustion engine. By properly piping and wiring these on-board components in the limited space at the front of the vehicle, it is possible to increase the space available for the vehicle interior, etc. In the vehicle drive device 10 of this embodiment, functional components that perform heat management using a heat medium in this manner are integrally configured with the vehicle drive device 10.

[0011] A preferred embodiment of such a vehicle drive device 10 will be described below. In this specification, the term "driving connection" refers to a state in which two rotating elements are connected to be able to transmit a driving force, and includes a state in which the two rotating elements are connected to rotate integrally, or a state in which the two rotating elements are connected to be able to transmit a driving force via one or more transmission members. Such transmission members include various members that transmit rotation at the same speed or at a variable speed, such as shafts, gear mechanisms, belts, chains, etc. In addition, the transmission members may also include engagement devices that selectively transmit rotation and driving force, such as friction engagement devices and meshing engagement devices. However, when the term "driving connection" is used for the rotating elements of a planetary gear mechanism, it refers to a state in which the rotating elements are connected to each other without passing through other rotating elements of the planetary gear mechanism. In addition, in this specification, "rotating integrally" refers to rotating integrally regardless of whether they are separable or not. In other words, a plurality of members that rotate integrally may be integrally formed from the same member, or may be made of different members and integrated by welding, spline coupling, or the like. Furthermore, in this specification, with regard to the arrangement of two elements, "overlapping when viewed in a particular direction" means that when a virtual line parallel to the line of sight is moved in each direction perpendicular to the virtual line, there exists at least a portion of an area where the virtual line intersects both of the two elements.

[0012] FIG. 1 is a diagram showing a vehicle 8 equipped with a vehicle drive device 10. The vehicle drive device 10 includes a rotating electric machine MG, an output member (described later) drivingly connected to wheels (W1, W2), and a power transmission mechanism GT that transmits driving force between the rotating electric machine MG and the output member. With the direction along the rotation axis X1 of the rotor 12 being taken as the axial direction L, the power transmission mechanism GT is disposed on a first axial side L1, which is one side of the axial direction L, relative to the rotor 12 included in the rotating electric machine MG. The rotating electric machine MG is a driving force source for the vehicle 8. The power transmission mechanism GT includes a reduction gear 16 and a differential gear mechanism 15.

[0013] The vehicle drive device 10 includes a case 20 including a rotating electric machine MG, a power transmission mechanism GT, and a first housing chamber E1 that houses oil. The case 20 also supports an inverter module INV, a power supply module PWR, and a third heat medium circuit module 46, which will be described later. Note that "support" is not limited to the case where the outside of the case 20 is used, but also includes a form in which the case 20 supports the module on its inner surface. In other words, at least one of the inverter module INV, the power supply module PWR, and the third heat medium circuit module 46 may be housed in the case 20.

[0014] The output member is drivingly connected to a pair of wheels (W1, W2). The pair of wheels includes a first wheel W1 and a second wheel W2, the first wheel W1 is drivingly connected to a first drive shaft DS1, and the second wheel W2 is drivingly connected to a second drive shaft DS2. In this embodiment, a pair of side gears (15a, 15b) which are output gears of the differential gear mechanism 15 include a first side gear 15a and a second side gear 15b. The first side gear 15a is drivingly connected to the first drive shaft DS1 via a connecting shaft 17, and the second side gear 15b is drivingly connected to the second drive shaft DS2. For example, the first side gear 15a and the connecting shaft 17 are connected by a spline connection, and the second side gear 15b and the second drive shaft DS2 are also connected by a spline connection. These connecting parts are spline engagement parts 15d. The output member is, for example, these spline engagement parts 15d. In addition, the output member may be the first side gear 15a, the second side gear 15b, the first drive shaft DS1, the second drive shaft DS2, and the connecting shaft 17.

[0015] In the following description, the direction along the rotation axis X1 of the rotor 12 is referred to as the "axial direction L" as described above. One side of the axial direction L is referred to as the "axial first side L1", and the other side of the axial direction L is referred to as the "axial second side L2". In this embodiment, the rotating electric machine MG, the reduction gear 16, and the differential gear mechanism 15 are arranged coaxially in the order described from the axial second side L2 to the axial first side L1. The vehicle drive device 10 of this embodiment has a single shaft configuration, and the shaft on which the rotating electric machine MG, the reduction gear 16, and the differential gear mechanism 15 are arranged, the shaft being centered on the rotation axis X1, is the rotation shaft of the vehicle drive device 10, and is also the rotation shaft of the rotating electric machine MG, the reduction gear 16, and the differential gear mechanism 15. In addition, the direction perpendicular to the rotation axis X1 of the rotor 12 is referred to as the "radial direction". In the radial direction, the side of the rotation axis X1 of the rotor 12 is referred to as the "radial inner side", and the opposite side is referred to as the "radial outer side". In addition, when the vehicle drive device 10 is mounted on the vehicle, the direction along the vertical direction is defined as the "upper-lower direction Z", the upper side is defined as the "upper side Z1 of the vertical direction Z", and the lower side is defined as the "lower side Z2 of the vertical direction Z". When the vehicle drive device 10 is mounted horizontally on the vehicle, one of the radial directions coincides with the vertical direction Z. In addition, the direction perpendicular to the axial direction L and the vertical direction Z is defined as the "front-rear direction H", one side of the front-rear direction H is defined as the "first front-rear direction side H1", and the other side is defined as the "second front-rear direction side H2". In this embodiment, the first front-rear direction side H1 is the front side of the vehicle 8, and the second front-rear direction side H2 is the rear side. In addition, the axial direction L corresponds to the "width direction" of the vehicle 8.

[0016] The rotating electric machine MG functions as a driving force source for the wheels (W1, W2). As shown in FIG. 1, the rotating electric machine MG includes a stator 11 fixed to a case 20 and a rotor 12 connected to the rotor shaft 13 so as to rotate integrally with the rotor shaft 13. The rotating electric machine MG is an inner rotor type rotating electric machine, and the rotor 12 is disposed radially inside the stator 11. The rotating electric machine MG is a rotating field type rotating electric machine, and the stator 11 includes a stator core 11a and a stator coil 11b wound around the stator core 11a. The rotor 12 includes a rotor core 12a and a permanent magnet (not shown) fixed to the rotor core 12a. The rotor shaft 13 is formed in a cylindrical shape coaxial with the rotor core 12a, and a sun gear SG of a planetary gear mechanism constituting a reducer 16 is disposed on the outer circumferential side of the rotor shaft 13 on a first axial side L1 so as to rotate integrally with the rotor shaft 13. As will be described later, the sun gear SG is an input element of the reduction gear 16.

[0017] 1, the reducer 16 is configured as a planetary gear mechanism including an input element that rotates integrally with the rotor shaft 13, a fixed element fixed to the case 20, an output element that rotates integrally with the differential input element (differential case 15c), and planetary gears. This planetary gear mechanism is a composite planetary gear mechanism including one sun gear SG, two ring gears (first ring gear RG1, second ring gear RG2), two planetary gears (first planetary gear PG1, second planetary gear PG2) that rotate integrally, and a carrier CR that rotatably supports the two planetary gears. In this embodiment, the first planetary gear PG1 is formed to have a smaller diameter than the second planetary gear PG2.

[0018] The sun gear SG rotates integrally with the rotor 12 and the rotor shaft 13. The second ring gear RG2 is fixed to the case 20. The first ring gear RG1 is disposed on the axial first side L1 relative to the second ring gear RG2 and is connected to the differential case 15c so as to rotate integrally with the differential case 15c. The second planetary gear PG2 meshes with the sun gear SG and the second ring gear RG2, and the first planetary gear PG1 rotates integrally with the second planetary gear PG2 and meshes with the first ring gear RG1. In this embodiment, the sun gear SG is an input element, the second ring gear RG2 is a fixed element, and the first ring gear RG1 is an output element. The carrier CR is not connected to any rotating element or fixed element.

[0019] The differential gear mechanism 15 is a bevel gear type differential gear mechanism, and includes a pinion 15p and side gears (15a, 15b) that are both bevel gears. The pinion 15p is rotatably supported by a pinion shaft 15s that is supported by a differential case 15c and arranged to extend along the radial direction. The pinion shaft 15s rotates integrally with the differential case 15c, and the pinion 15p is configured to be rotatable (rotate) about the pinion shaft 15s and rotatable (revolve) about the rotation axis X1 of the differential case 15c. The multiple pinion shafts 15s are arranged radially (for example, in a cross shape) about the rotation axis X1 of the differential case 15c, and the pinion 15p is attached to each of the multiple pinion shafts 15s. The differential case 15c accommodates therein the pinion 15p, the side gears (15a, 15b), and the pinion shaft 15s.

[0020] The side gears (15a, 15b) are provided with a first side gear 15a and a second side gear 15b, and are arranged in a pair spaced apart from each other in the axial direction L. The first side gear 15a and the second side gear 15b are arranged to mesh with the pinions 15p, respectively, and to rotate about the rotation axis X1 of the differential case 15c. As shown in FIG. 1, the first side gear 15a is connected to a connecting shaft 17 that passes through the reduction gear 16 and the radially inner side of the hollow cylindrical rotor shaft 13 and extends along the axial direction L. The connecting shaft 17 is connected to a first drive shaft DS1 that is drivingly connected to a first wheel W1, which is a wheel on the second axial side L2, so as to rotate integrally with the first drive shaft DS1. Therefore, the first side gear 15a is drivingly connected to the first wheel W1 via the connecting shaft 17. Further, the second side gear 15b is connected to rotate integrally with a second drive shaft DS2 which is drivingly connected to a second wheel W2 which is a wheel on the first axial side L1.

[0021] The first drive shaft DS1, the second drive shaft DS2, the connecting shaft 17, the first side gear 15a, and the second side gear 15b, which are drivingly connected to the wheels (W1, W2) and rotate integrally with the wheels, can all be considered as rotating members corresponding to the output members. The first side gear 15a and the second side gear 15b are the differential gear mechanism 15 and can also be considered as output members. Each of the first side gear 15a and the second side gear 15b includes a gear portion that meshes with the pinion 15p and a spline engagement portion 15d that is connected to the connecting shaft 17 or the second drive shaft DS2. When considered functionally separately, the gear portion corresponds to the rotating member included in the differential gear mechanism 15, and the spline engagement portion 15d corresponds to the output member.

[0022] Fig. 2 is a schematic exploded perspective view of the vehicle drive device 10. Fig. 3 is a side view of the vehicle drive device 10. Fig. 4 is a rear view of the vehicle drive device 10. The vehicle drive device 10 includes an inverter module INV for controlling the drive of the rotating electric machine MG. The inverter module INV is a circuit module that controls the drive of the rotating electric machine MG. The vehicle drive device 10 also includes a power supply module PWR.

[0023] In this embodiment, the case 20 includes a first housing chamber E1 that houses the rotating electric machine MG, the power transmission mechanism GT, and the oil OL. The case 20 also includes a second housing chamber E2 that houses the inverter module INV. The case 20 also includes a partition wall 28 that partitions the first housing chamber E1 and the second housing chamber E2.

[0024] The case 20 includes a case body 20m which is a housing member that is the core of the first housing chamber E1 and the second housing chamber E2. The case body 20m has a first case portion 21 and a second case portion 22. The first case portion 21 is a portion in which the second housing chamber E2 that houses the inverter module INV and the power supply module PWR is formed. The second case portion 22 is a portion in which the first housing chamber E1 that houses the rotating electric machine MG and the power transmission mechanism GT is formed.

[0025] In this embodiment, the case 20 is integrally formed with the first storage chamber E1, the second storage chamber E2, and a partition wall 28 that partitions the first storage chamber E1 and the second storage chamber E2. That is, in this embodiment, a form in which the first case part 21, the second case part 22, and the partition wall 28 are integrally formed by the same member is illustrated. However, the structure of the case 20 is not limited to this. The case 20 may be formed without the partition wall 28, in which the first case part 21 and the second case part 22 are formed by different members and integrated by fastening members such as bolts, welding, or the like. When the first case part 21 and the second case part 22 are formed by different members, a wall of at least one member is present at the boundary between the first case part 21 and the second case part 22. When the case 20 is integrated by combining different members, one or both of the walls at the boundary may be considered as the partition wall 28.

[0026] In this embodiment, the case 20 includes a cover member. The cover member includes a first cover 23, a second cover 24, and a third cover 25. The first case portion 21 is formed in a rectangular box shape with an upper side Z1 in the vertical direction Z open when mounted on the vehicle. The first case portion 21 includes a peripheral wall portion 26 that surrounds the first opening 20a and is arranged to extend along the vertical direction Z when mounted on the vehicle. The first opening 20a is closed by the first cover 23. The first opening 20a is an opening of the case 20 that houses the inverter module INV, and the first cover 23 is a cover that closes this opening. In this embodiment, the first housing chamber E1 and the second housing chamber E2 are arranged to be aligned in the vertical direction Z.

[0027] The second case portion 22 is formed in a cylindrical shape with both sides open in the axial direction L, and includes a cylindrical peripheral wall portion 27. The cylindrical peripheral wall portion 27 surrounds the power transmission mechanism GT from the radial outside, and corresponds to a portion surrounding the first housing chamber E1 of the case 20. The opening formed on the second axial side L2 is the second opening 20b, and the opening formed on the first axial side L1 is the third opening 20c. The second opening 20b is closed by the second cover 24, and the third opening 20c is closed by the third cover 25. The second cover 24 and the third cover 25 are formed with through holes through which the above-mentioned drive shafts (first drive shaft DS1, second drive shaft DS2) pass.

[0028] In this embodiment, the first housing chamber E1 and the second housing chamber E2 are arranged to be aligned in the vertical direction Z. The inverter module INV is arranged above the rotating electric machine MG at a position Z1 above the rotating electric machine MG and overlaps with the rotating electric machine MG when viewed in the vertical direction Z. The power supply module PWR is arranged adjacent to the inverter module INV on the first axial side L1. As shown in Figs. 2 to 4, the power supply module PWR is arranged above the power transmission mechanism GT at a position Z1 above the power transmission mechanism GT and overlaps with the power transmission mechanism GT when viewed in the vertical direction Z.

[0029] 5 is a control block diagram of the vehicle drive device 10. The power supply module PWR includes at least one of a converter 61 (voltage conversion circuit) electrically connected to the vehicle battery B2 to convert the voltage of the vehicle battery B2, a charging circuit electrically connected to the vehicle battery B2 to charge the vehicle battery B2 from the external power source 60, and a power supply circuit electrically connected to the vehicle battery B2 to supply power from the vehicle battery B2 to the outside. In this embodiment, a charging power supply circuit 62 having a bidirectional function of charging the vehicle battery B2 and supplying power from the vehicle battery B2 is illustrated. That is, the charging power supply circuit 62 has the functions of a charging circuit and a power supply circuit. In this embodiment, a high-voltage circuit unit including the inverter module INV and the power supply module PWR is formed.

[0030] 5, the rotating electric machine MG is electrically connected to an in-vehicle battery B2, which is a DC power source configured with an electricity storage device such as a secondary battery or a capacitor, via an inverter circuit 66. The rotating electric machine MG has a function as a motor (electric motor) that receives power from the in-vehicle battery B2 to generate power, and a function as a generator (electric power generator) that receives power from the wheels (W1, W2) to generate power.

[0031] The rotating electric machine MG generates driving force by running using the power stored in the on-board battery B2, and also generates electricity using driving force transmitted from the pair of wheels (W1, W2) to charge the on-board battery B2. The on-board battery B2 is a high-voltage DC power source with a rated voltage of about 48 volts to 400 volts. The on-board battery B2 has a large power capacity and is large in size in order to supply power to the rotating electric machine MG, which serves as the driving force source for the wheels. For example, it is arranged under the cabin floor of the vehicle 8 in order to ensure space in the vehicle interior (cabin), etc.

[0032] In this embodiment, the in-vehicle battery B2 is configured to be chargeable not only by the power generated by the rotating electric machine MG, but also by power supplied from an external power source 60 such as an AC commercial power source having a rated voltage of about 100 volts to 240 volts. Therefore, the in-vehicle battery B2 is configured to be connectable to the external power source 60 via a charging power supply circuit 62. In order to control the charging power supply circuit 62, a charging power supply control unit 64 is provided.

[0033] In recent years, it has been proposed to use the vehicle battery B2 of an electric vehicle or a hybrid vehicle as an emergency power source in the event of a disaster or the like. The charging power supply circuit 62 is configured to have a function of a power supply circuit in addition to a function of a charging circuit so that the vehicle battery B2 can be used as such an emergency power source. Naturally, when such use of the vehicle battery B2 is not taken into consideration, the charging power supply circuit 62 may be configured to have only the function of a charging circuit.

[0034] In this embodiment, the vehicle-mounted battery B2 also supplies power to the low-voltage DC power supply B1, which has a rated voltage of about 12 volts to 24 volts. The low-voltage DC power supply B1 serves as a power source for auxiliary devices such as headlights, power windows, power steering, vehicle-mounted air conditioner, and electric oil pump of the vehicle 8, and as a power source for various control devices in the vehicle 8. Conventionally, in a typical vehicle 8, the low-voltage DC power supply B1 is charged by power generated by an alternator linked to a driving power source (for example, an internal combustion engine) of the vehicle 8. However, in this embodiment, the low-voltage DC power supply B1 is configured to be charged by power from the vehicle-mounted battery B2 (high-voltage DC power supply) which has a higher voltage and a larger storage capacity than the low-voltage DC power supply B1. This eliminates the need to mount an alternator, and also makes it possible to suppress power loss of the vehicle's driving power source (the rotating electric machine MG in this embodiment) associated with driving the alternator.

[0035] In order to charge the low-voltage DC power supply B1 with the power of the vehicle-mounted battery B2 in this way, a converter 61 (voltage conversion circuit) that converts the voltage of the vehicle-mounted battery B2 is provided. As described above, since the rated voltage of the vehicle-mounted battery B2 is higher than the rated voltage of the low-voltage DC power supply B1, the converter 61 is, for example, configured by a step-down DC / DC converter. There are non-insulated DC / DC converters such as chopper type and charge pump type, and insulated type using a transformer. When it is preferable that the circuit to which power is supplied from the vehicle-mounted battery B2 and the circuit to which power is supplied from the low-voltage DC power supply B1 are electrically insulated, the converter 61 may be of an insulated type. The insulated DC / DC converter is configured to include a switching element, and the converter 61 is controlled by a converter control unit 63.

[0036] Some vehicles 8 are equipped with an AC power socket (alternating current power socket) for supplying power to general home appliances and the like. Such an AC power socket is configured to be capable of outputting alternating current with a rated voltage of 100 volts to 200 volts. The AC power supplied from the AC power socket is generated from the vehicle battery B2 by using an inverter (not shown). Such an inverter also corresponds to a voltage conversion circuit, and when the vehicle has the inverter, the inverter and an inverter control unit that controls it can also be included in the power supply module PWR.

[0037] Thus, the power supply module PWR is electrically connected to the vehicle-mounted battery B2 and includes at least one of the converter 61 (voltage conversion circuit) that converts the voltage of the vehicle-mounted battery B2, a charging circuit for charging the vehicle-mounted battery B2 from the external power supply 60, and a power supply circuit for supplying power from the vehicle-mounted battery B2 to the outside. In this embodiment, the charging power supply control unit 64 and converter control unit 63 described above are also included in the power supply module PWR.

[0038] As shown in FIG. 5, the rotating electric machine MG is driven and controlled by a rotating electric machine control unit 65 based on a target torque of the rotating electric machine MG that is set according to a command from a vehicle control device 100 that is a higher-level control device. The rotating electric machine control unit 65 controls switching of an inverter circuit 66 that is composed of a plurality of switching elements, and causes the inverter circuit 66 to convert power between a direct current and a multi-phase (three-phase in this embodiment) alternating current. The operating voltage of the rotating electric machine control unit 65 is about 3.3 volts to 5 volts, the input / output voltage of the inverter circuit 66 is about 48 volts to 400 volts, and the voltage of a switching control signal of the switching element that constitutes the inverter circuit 66 is about 15 volts to 24 volts. For this reason, a driver 68 that amplifies the voltage of the switching control signal output from the rotating electric machine control unit 65, increases the driving force, and supplies it to the inverter circuit 66 is provided between the rotating electric machine control unit 65 and the inverter circuit 66.

[0039] The inverter circuit 66 is configured with a plurality of switching elements. The inverter circuit 66 has a plurality of sets (three sets in this case) of arms for one AC phase, each set being configured with a series circuit of an upper-stage switching element on the positive side of DC and a lower-stage switching element on the negative side. Each switching element is provided with a freewheel diode with a forward direction from the negative electrode to the positive electrode (from the lower stage to the upper stage). It is preferable to apply a power semiconductor element such as an IGBT (Insulated Gate Bipolar Transistor), a power MOSFET (Metal Oxide Semiconductor Field Effect Transistor), a SiC-MOSFET (Silicon Carbide - Metal Oxide Semiconductor FET), a SiC-SIT (SiC - Static Induction Transistor), or a GaN-MOSFET (Gallium Nitride - MOSFET) to the switching element. In this embodiment, the inverter circuit 66 is configured as a power module in which switching elements are integrated together with a freewheel diode.

[0040] The inverter module INV is configured to include at least switching elements that configure an inverter circuit 66. In this embodiment, the inverter module INV further includes a rotating electrical machine control unit 65 and a driver 68. That is, in this embodiment, the inverter module INV is configured to include the rotating electrical machine control unit 65, the driver 68, and the inverter circuit 66.

[0041] The rotating electric machine control unit 65 performs current feedback control based on the rotational position of the rotor 12 (magnetic pole position of the permanent magnet), the rotational speed of the rotor 12, and the current flowing through the stator coil 11b of each of the three phases, to drive and control the rotating electric machine MG via the inverter circuit 66. The rotational position of the rotor 12 is detected by a rotation sensor S1 such as a resolver or an inductive position sensor. The current flowing through the stator coil 11b is detected by a current sensor S2. The current sensor S2 is preferably a non-contact type current sensor installed near a power line such as a bus bar connecting the inverter circuit 66 and the stator coil 11b of the rotating electric machine MG.

[0042] The power supply module PWR is configured to include at least a converter 61 (voltage conversion circuit) and a charging power supply circuit 62. In this embodiment, the converter 61 and the charging power supply circuit 62 are configured using a common board. In this embodiment, the power supply module PWR is also configured to include the converter 61, a converter control unit 63, the charging power supply circuit 62, and a charging power supply control unit 64.

[0043] In this embodiment, a DC link capacitor 67 (smoothing capacitor) that smoothes the voltage on the DC side of the inverter circuit 66 is provided on the DC side of the inverter circuit 66, that is, between the inverter circuit 66 and the in-vehicle battery B2. The inverter module INV may include the DC link capacitor 67. The inverter module INV may also include a control board ECU, which will be described later.

[0044] In this embodiment, the rotating electrical machine control unit 65 included in the inverter module INV, and the converter control unit 63 and the charging power supply control unit 64 included in the power supply module PWR are formed on one and the same board to configure a control board ECU. The control board ECU can also be called an integrated control board in which the functions of multiple control units are integrated.

[0045] A driver 68 is disposed on the upper side Z1 of the inverter circuit 66 in the vertical direction Z. A control board ECU is disposed across the rotating electric machine control unit 65, the converter control unit 63, and the charging power supply control unit 64. The control board ECU is disposed so that the inverter circuit 66, the driver 68, and the rotating electric machine control unit 65 overlap, the converter 61 and the converter control unit 63 overlap, and the charging power supply circuit 62 and the charging power supply control unit 64 overlap when viewed in the vertical direction. In this embodiment, as shown in Figs. 2 to 4, the power supply module PWR is disposed adjacent to the inverter module INV on the first axial side L1. The control board ECU is disposed across the rotating electric machine control unit 65, the converter control unit 63, and the charging power supply control unit 64 along the axial direction L. As shown in Figs. 2 to 4, the control board ECU is disposed between the inverter circuit 66 (switching element) and a third heat medium circuit module 46 described later in the vertical direction Z.

[0046] 6 is a perspective view showing an example of the arrangement of the control board ECU, the inverter module INV, the power supply module PWR, and the cooling unit 38. When the rotating electric machine MG is driven, a large current flows through the switching elements constituting the inverter circuit 66, causing the switching elements to generate heat. Therefore, the inverter circuit 66, which includes a plurality of switching elements, generates a large amount of heat. The inverter circuit 66 is cooled by the cooling unit 38, which will be described later.

[0047] The vehicle drive device 10 includes a cooling unit 38 that exchanges heat between the inverter module INV and a first heat medium Q1. The cooling in the cooling unit 38 includes a form of direct heat exchange between the cooling target part and the first heat medium Q1, and a form of heat exchange with the first heat medium Q1 via a heat transfer medium such as oil OL or a heat sink. In this embodiment, the cooling unit first surface 38a, which is the upper surface of the cooling unit 38 that contacts the cooling target part, is cooled by heat exchange with the first heat medium Q1 flowing inside the cooling unit 38. Examples of the "first heat medium Q1" include antifreeze, water, oil, etc. The first heat medium Q1 corresponds to the "heat medium". The cooling unit 38 corresponds to the "third heat exchanger".

[0048] As shown in FIG. 6, in this embodiment, an inverter circuit 66 (switching element), a DC link capacitor 67, a converter 61, and a charging power supply circuit 62 are attached to a cooling unit first surface 38a, which is the upper surface of the cooling unit 38. The DC link capacitor 67, which smoothes the DC voltage that generates pulsation, generates heat due to the inflow and outflow of current. The converter 61 also includes a switching element, which also generates heat due to the current that flows during switching operation. The charging power supply circuit 62 also generates heat because a current supplied from the external power source 60 flows to charge the in-vehicle battery B2. The cooling unit 38 includes a part of the first heat medium circuit 30 described later, and these heat-generating members are appropriately cooled by being attached to the cooling unit first surface 38a. The inverter circuit 66 generates the most heat and has the highest temperature.

[0049] 2 and 4, in this embodiment, a power supply module PWR is attached to a cooling unit second surface 38b, which is the lower surface of the cooling unit 38. An inverter module INV may also be attached to the cooling unit second surface 38b. That is, the power supply module PWR or the inverter module INV may be attached to both the cooling unit first surface 38a and the cooling unit second surface 38b.

[0050] 7 is a diagram illustrating a first heat medium circuit 30 including a cooling unit 38. In the illustrated example, the cooling unit 38 is provided so that the first heat medium Q1 flows from the inverter module INV side to the power supply module PWR side. Note that the cooling unit 38 may be provided so that the first heat medium Q1 flows from the power supply module PWR side to the inverter module INV side.

[0051] The vehicle drive device 10 includes a first heat medium circuit 30 in which a first heat medium Q1 circulates. The first heat medium circuit 30 includes a first heat exchanger 31 and a second heat exchanger 32, which will be described later. The first heat medium circuit 30 also includes a first heat medium pump 36. The first heat medium circuit 30 also includes a radiator 37 that exchanges heat between the first heat medium Q1 and the outside air. The first heat medium circuit 30 also includes a condenser 49, which will be described later. In the illustrated example, the first heat medium pump 36 is disposed upstream of the first heat exchanger 31 and the second heat exchanger 32, but may be disposed downstream. In the illustrated example, the first heat medium pump 36 is disposed downstream of the radiator 37 in the first heat medium circuit 30, but may be disposed upstream. The first heat medium circuit 30 corresponds to the "heat medium circuit."

[0052] In this embodiment, a cooling unit 38 that performs heat exchange between the inverter module INV and the first heat medium Q1 is provided upstream of the first heat exchanger 31 and the second heat exchanger 32 in the first heat medium circuit 30. The first heat medium circuit 30 is also provided with an exhaust heat utilization unit 39 that utilizes the heat of the first heat medium Q1. An example of the exhaust heat utilization unit 39 is a heater that warms the interior of the vehicle or electronic components such as the on-board battery B2 in cold weather. For example, air sent by a blower into the interior of the vehicle 8 may be warmed by the exhaust heat utilization unit 39. For example, the exhaust heat utilization unit 39 may be connected to a second heat medium circuit 50 described later to circulate the first heat medium Q1 and warm the on-board battery B2.

[0053] The vehicle drive device 10 includes a third heat medium circuit 40 in which the third heat medium Q3 circulates. A condenser 49 is connected to the third heat medium circuit 40. In the condenser 49, heat exchange is performed between the third heat medium Q3 and the first heat medium Q1. The third heat medium circuit 40 includes a third heat medium first path 40a including a flow path of the third heat medium Q3 from the condenser 49 to the evaporator 44, a third heat medium second path 40b including a flow path of the third heat medium Q3 from the compressor 42 to the condenser 49, and a third heat medium third path 40c including a flow path of the third heat medium Q3 including the chiller 52. For example, the third heat medium Q3 flowing through the third heat medium first path 40a is at a lower temperature than the third heat medium second path 40b and the third heat medium third path 40c. Also, for example, the third heat medium Q3 flowing through the third heat medium third path 40c is at a lower temperature than the third heat medium second path 40b. In this embodiment, the third heat medium Q3 is a refrigerant for an in-vehicle air conditioner. In this embodiment, the condenser 49 is a water-cooled condenser. The condenser 49 corresponds to the "fourth heat exchanger."

[0054] A part of the flow path constituting the third heat medium circuit 40 can also be formed by utilizing the first cover 23 (see FIG. 2) of the case 20. For example, the control valves V (first valve V1, second valve V2, third valve V3, and fourth valve V4) that control the flow rate or flow path of the third heat medium Q3 in the third heat medium circuit 40 are attached to the first cover first surface 23a of the first cover 23. In addition, for example, the accumulator 41, the condenser 49, and the chiller 52 are attached to the second cover second surface 23b of the first cover 23.

[0055] As shown in FIG. 2, the vehicle drive device 10 includes a third heat medium circuit module 46. The third heat medium circuit module 46 constitutes at least a part of the third heat medium circuit 40. In this embodiment, the third heat medium circuit module 46 is constituted by the third heat medium circuit 40 and the control valve V formed in the first cover 23. As shown in FIGS. 2 to 4, the third heat medium circuit module 46 is disposed on the upper side Z1 in the vertical direction Z with respect to the inverter module INV and the power supply module PWR, and is positioned so as to overlap with the inverter module INV and the power supply module PWR as viewed in the vertical direction. Moreover, the third heat medium circuit module 46 is fixed integrally to the case 20 as shown in FIGS. 2 to 4.

[0056] Here, the portion of the first cover 23 where the third heat medium circuit 40 is formed is referred to as a third heat medium manifold 47. A condenser 49 (see FIG. 7) for cooling the third heat medium Q3 by heat exchange with the first heat medium Q1 is further attached to the third heat medium manifold 47 as a functional component constituting the third heat medium circuit 40.

[0057] The third heat medium circuit module 46 includes a third heat medium manifold 47 that configures a flow path of the third heat medium Q3 in the third heat medium circuit 40, and a control valve V attached to the third heat medium manifold 47. Note that the third heat medium circuit module 46 only needs to configure at least a part of the third heat medium circuit 40 that circulates the third heat medium Q3, and in addition to the third heat medium manifold 47, the third heat medium circuit module 46 may also include an accumulator 41, a condenser 49, and a chiller 52.

[0058] As shown in FIG. 7, the third heat medium circuit 40 is provided with a path (third heat medium first path 40a) that runs from the condenser 49 via the first valve V1, through the evaporator 44 to the accumulator 41, and a path (third heat medium second path 40b) that runs from the condenser 49 via the second valve V2 to the accumulator 41, further through the compressor 42 and the cabin condenser 43, and back to the condenser 49 via the third valve V3.

[0059] The evaporator 44 is a functional component that is the core of the cooling system, and removes heat from the surroundings by vaporizing the third heat medium Q3, and releases cool air into the vehicle cabin. The accumulator 41 separates the liquid from the third heat medium Q3, which is a mixture of gas and liquid, and supplies only the gas (third heat medium gas) to the compressor 42. The compressor 42 compresses the relatively low-temperature, low-pressure third heat medium gas to a high-temperature, high-pressure state. The cabin condenser 43 is a heat source for heating using a heat pump system, and releases the heat condensed by the compressor 42 into the vehicle cabin. The third heat medium Q3 that leaves the cabin condenser 43 flows to the condenser 49 via the third valve V3, which is an expansion valve.

[0060] The above-mentioned compressor 42, cabin condenser 43, and evaporator 44 are included in a cabin air conditioning unit that adjusts the temperature and air volume during heating and cooling and selects the air outlet in the vehicle air conditioner.

[0061] In this embodiment, the battery heat sink 54 also cools the in-vehicle battery B2 by heat exchange with the second heat medium Q2, and the second heat medium Q2 whose temperature has increased is cooled by heat exchange with the third heat medium Q3 in the chiller 52. For this reason, a third heat medium third path 40c is formed as a path through which the third heat medium Q3 travels from the condenser 49 to the accumulator 41 via the fourth valve V4 and the chiller 52.

[0062] The chiller 52 is connected to a second heat medium circuit 50 through which the second heat medium Q2 coming out of the chiller 52 returns to the chiller 52 via a battery heat sink 54 and a second heat medium pump 53. The chiller 52 exchanges heat between the second heat medium Q2 and the third heat medium Q3. For example, the second heat medium Q2 whose temperature has increased due to heat exchange with the battery heat sink 54 is cooled in the chiller 52. By providing the second heat medium circuit 50 for cooling the vehicle-mounted battery B2 and the third heat medium third path 40c for cooling the second heat medium Q2 flowing through the second heat medium circuit 50, it becomes easier to relax the restriction on the input / output current to the vehicle-mounted battery B2 even in cases where the current flowing through the vehicle-mounted battery B2 increases and the temperature of the vehicle-mounted battery B2 rises, such as during quick charging or high-speed driving. Examples of the "second heat medium Q2" include antifreeze, water, oil, and the like. The chiller 52 corresponds to the "fifth heat exchanger."

[0063] The vehicle drive device 10 includes an oil circuit 55 in which the oil OL circulates. In the vehicle drive device 10, the rotating electric machine MG and the power transmission mechanism GT are often lubricated and cooled by the oil OL, and the vehicle drive device 10 of this embodiment also uses the oil OL to lubricate the oil OL accommodated in the first accommodation chamber E1. For example, the oil OL accumulated in an oil reservoir formed on the lower side Z2 of the case 20 is scooped up by the oil pump OP and the gears of the power transmission mechanism GT, and is supplied to the lubrication target parts such as the bearings of each gear and the cooling target parts such as the stator coil 11b of the rotating electric machine MG and the bearings of the rotor shaft 13. The oil circuit 55 includes the first accommodation chamber E1. The oil circuit 55 also includes flow paths formed in the walls of the case 20 and the rotating shaft of the rotating member, and flow paths formed by pipes arranged in the case 20. In the illustrated example, the oil circuit 55 has a path in which the oil OL branches off and is supplied to the rotating electric machine MG or the power transmission mechanism GT, but it may also be a path in which the oil OL supplied to the rotating electric machine MG is supplied to the power transmission mechanism GT. Also, it may be a path in which the oil OL supplied to the power transmission mechanism GT is supplied to the rotating electric machine MG. Examples of the "oil OL" include automatic transmission fluid (ATF) and gear oil. As shown in FIG. 7, the oil pump OP, the first heat transfer medium pump 36, and the second heat transfer medium pump 36 are electric pumps rotated by electric motors.

[0064] 8 is a schematic cross-sectional view of the first heat exchanger 31 and the second heat exchanger 32. The vehicle drive device 10 includes the first heat exchanger 31 that exchanges heat between the first heat medium Q1 and the oil OL. The first heat exchanger 31 is connected to the first heat medium circuit 30 and the oil circuit 55. The first heat exchanger 31 cools the oil OL flowing through the oil circuit 55 by exchanging heat with the first heat medium Q1 flowing through the first heat medium circuit 30. The first heat exchanger 31 is disposed in the second housing chamber E2.

[0065] The first heat exchanger 31 is configured to have a larger amount of heat exchangeable energy than the second heat exchanger 32 when the oil temperature, which is the temperature of the oil OL, is in a predetermined first temperature range D1. Although simplified in FIG. 8, the first heat medium path and the oil path in the first heat exchanger 31 of this embodiment are formed in a zigzag state so that the length of the first heat medium path and the oil path extending adjacent to each other can be sufficiently secured, and the oil OL can be cooled by appropriately exchanging heat between the first heat medium Q1 and the oil OL. Examples of the first heat exchanger 31 include a multi-plate type heat exchanger, a multi-tube type heat exchanger, a first heat medium path and an oil path formed in the wall of the case 20, and a heat exchanger attached to the outer wall of the case 20. In this embodiment, the first heat exchanger 31 is a heat exchanger having a labyrinth type heat exchange structure.

[0066] The vehicle drive device 10 includes a second heat exchanger 32 that exchanges heat between the first heat medium Q1 and the oil OL. The second heat exchanger 32 is connected to the first heat medium circuit 30 and the oil circuit 55. The second heat exchanger 32 cools the oil OL flowing through the oil circuit 55 by exchanging heat with the first heat medium Q1 flowing through the first heat medium circuit 30. The second heat exchanger 32 is formed in the partition wall 28.

[0067] The second heat exchanger 32 is configured to have a larger amount of heat exchangeable energy than the first heat exchanger 31 when the oil temperature is in the second temperature range D2 lower than the first temperature range D1. The second heat exchanger 32 is configured to have a smaller pressure loss of the oil OL than the first heat exchanger 31 when the oil temperature is in the second temperature range D2. Examples of the second heat exchanger 32 include a multi-plate heat exchanger, a multi-tube heat exchanger, a first heat medium path and an oil path formed in the wall of the case 20, and a heat exchanger attached to the outer wall of the case 20. In the illustrated example, the second heat exchanger 32 is a multi-layered flow path (a two-layered flow path in FIG. 8) formed in the wall of the case 20.

[0068] Here, the flow rate of the oil OL flowing into the first heat exchanger 31 is defined as a flow rate F1. The flow rate of the oil OL flowing into the second heat exchanger 32 is defined as a flow rate F2. The oil circuit 55 is configured so that the flow rate F1 of the first heat exchanger 31 when the oil temperature is in the first temperature range D1 is greater than the flow rate F2 of the second heat exchanger 32 when the oil temperature is in the second temperature range D2. That is, the flow rate F1 of the first heat exchanger 31 when the oil temperature is in the first temperature range D1 is greater than the flow rate F2 of the second heat exchanger 32 when the oil temperature is in the second temperature range D2. The flow rates F1 and F2 are, for example, in the range of 1 L / min or more and 10 L / min or less.

[0069] The flow rates F1 and F2 are, for example, the flow rates when the temperature difference, which is the difference between the oil temperature and the water temperature, which is the temperature of the first heat medium Q1, and the flow rate of the first heat medium Q1 are within a predetermined range. The temperature difference range is, for example, from 0° C. to 130° C. The flow rate range of the first heat medium Q1 is, for example, from 1 L / min to 10 L / min.

[0070] Here, the upper limit temperature of the first temperature range D1 is the upper limit T1u, and the lower limit temperature of the first temperature range D1 is the lower limit T1d. The upper limit temperature of the second temperature range D2 is the upper limit T2u, and the lower limit temperature of the second temperature range D2 is the lower limit T2d. For example, the first heat exchanger 31 and the second heat exchanger 32 are configured so that the flow rate F1 is greater than the flow rate F2 when the oil temperature is the upper limit T1u of the first temperature range D1. For example, the first heat exchanger 31 and the second heat exchanger 32 are configured so that the flow rate F1 is greater than the flow rate F2 when the oil temperature is the lower limit T1d of the first temperature range D1. For example, the first heat exchanger 31 and the second heat exchanger 32 are configured so that the flow rate F2 is greater than the flow rate F1 when the oil temperature is the upper limit T2u of the second temperature range D2. Also, for example, the first heat exchanger 31 and the second heat exchanger 32 are configured so that the flow rate F2 is greater than the flow rate F1 when the oil temperature is at the lower limit T2d of the second temperature range D2.

[0071] In this embodiment, the first heat exchanger 31 and the second heat exchanger 32 are configured so that the flow rate F1 of the first heat exchanger 31 when the oil temperature is in the first temperature range D1 is greater than the flow rate F2 of the second heat exchanger 32 when the oil temperature is in the second temperature range D2. The first heat exchanger 31 and the second heat exchanger 32 may be configured so that the flow rate F2 of the second heat exchanger 32 when the oil temperature is in the second temperature range D2 is greater than the flow rate F1 of the first heat exchanger 31 when the oil temperature is in the second temperature range D2.

[0072] The case 20 includes a first member 81 and a second member 82 attached to a wall of the case 20. In this embodiment, the wall of the case 20 is a partition wall main body 28m. The partition wall main body 28m is a member constituting a wall surrounding the first storage chamber E1 or the second storage chamber E2. The first member 81 and the second member 82 are attached to a partition wall first surface 28a, which is the surface of the partition wall 28 facing the second storage chamber E2, or a partition wall second surface 28b, which is the surface facing the first storage chamber E1. The first member 81 and the second member 82 are plate-shaped members, and the first member 81 is disposed between the partition wall main body 28m and the second member 82 in the vertical direction Z. A first flow path 32a is formed between the first member 81 and the second member 82.

[0073] A second flow path 32b is formed between the first member 81 and the partition wall main body 28m. In this embodiment, the first flow path 32a and the second flow path 32b function as the second heat exchanger 32. The second member 82 may be directly attached to the wall of the case 20, or may be indirectly attached to the wall of the case 20 by being attached to the first member 81. The first member 81 and the second member 82 are fixed to the partition wall main body 28m by, for example, a fastening member (not shown).

[0074] In this embodiment, the first member 81 and the second member 82 are attached to the partition wall first surface 28a of the partition wall main body 28m, the first flow path 32a is an oil path in the second heat exchanger 32, and the second flow path 32b is a first heat medium path in the second heat exchanger 32. The first heat medium path in the second heat exchanger 32 is disposed on the upper side Z1 of the oil path in the second heat exchanger 32 in the vertical direction Z. The first heat medium path and the oil path in the second heat exchanger 32 are linear flow paths. In addition, the first heat medium path in the second heat exchanger 32 has a plurality of ribs 85 formed aligned in the flow path direction.

[0075] The vehicle drive device 10 includes a switching valve V6 that switches the first heat medium circuit 30. When the oil temperature is equal to or higher than a switching temperature Tc that is set between the lower limit T1d of the first temperature range D1 and the upper limit T2u of the second temperature range D2, the switching valve V6 switches the first heat medium circuit 30 so that the first heat medium Q1 does not pass through the second heat exchanger 32 but passes through the first heat exchanger 31. When the oil temperature is lower than the switching temperature Tc, the switching valve V6 switches the first heat medium circuit 30 so that the first heat medium Q1 does not pass through the first heat exchanger 31 but passes through the second heat exchanger 32. In the illustrated example, the first heat medium circuit 30 is provided with a check valve V16 that prevents the first heat medium Q1 from flowing back to the first heat exchanger 31 and the second heat exchanger 32.

[0076] The vehicle drive device 10 includes a switching valve V9 that switches the oil circuit 55. When the oil temperature is equal to or higher than a switching temperature Tc that is set between the lower limit T1d of the first temperature range D1 and the upper limit T2u of the second temperature range D2, the switching valve V9 switches the oil circuit 55 so that the oil OL does not pass through the second heat exchanger 32 but passes through the first heat exchanger 31. When the oil temperature is lower than the switching temperature Tc, the switching valve V9 switches the oil circuit 55 so that the oil OL does not pass through the first heat exchanger 31 but passes through the second heat exchanger 32. In the illustrated example, the oil circuit 55 is provided with a check valve V19 that prevents the oil OL from flowing back to the first heat exchanger 31 and the second heat exchanger 32. In this embodiment, the switching valve V6 and the switching valve V9 are control valves that operate in response to a control signal based on the detection result of an oil temperature sensor (not shown). The switching valve V6 or the switching valve V9 may be a thermostatic valve. The switching valve V6 and the switching valve V9 correspond to the "switching mechanism."

[0077] In this embodiment, the switching temperature Tc is an intermediate temperature between the lower limit T1d of the first temperature range D1 and the upper limit T2u of the second temperature range D2. Note that in this embodiment, the lower limit T1d and the upper limit T2u are different temperatures, but they may be the same temperature. Also, the lower limit T1d of the first temperature range D1 and the switching temperature Tc may be the same temperature. Also, the upper limit T2u of the second temperature range D2 and the switching temperature Tc may be the same temperature.

[0078] The first heat medium circuit 30 is provided with a switching valve V8 that causes the first heat medium Q1 to flow to either the radiator 37 or the exhaust heat utilization section 39. The switching valve V8 is configured to cause the first heat medium Q1 that has undergone heat exchange in the first heat exchanger 31 to flow to either the radiator 37 or the condenser 49. The switching valve V8 is also configured to cause the first heat medium Q1 that has undergone heat exchange in the second heat exchanger 32 to flow to either the radiator 37 or the exhaust heat utilization section 39. The switching valve V8 corresponds to a "switching section."

[0079] As shown in FIG. 7, the first heat medium circuit 30 is provided with a switching valve V7 that allows the first heat medium Q1 to flow to either the radiator 37 or the condenser 49. The switching valve V7 is configured to allow the first heat medium Q1 that has undergone heat exchange in the first heat exchanger 31 to flow to either the radiator 37 or the condenser 49. The switching valve V7 is also configured to allow the first heat medium Q1 that has undergone heat exchange in the second heat exchanger 32 to flow to either the radiator 37 or the condenser 49. In a configuration in which the heat of the first heat medium Q1 can be utilized by the condenser 49, such as when heating is performed by an in-vehicle air conditioner, the condenser 49 corresponds to the "exhaust heat utilization unit" and the switching valve V7 corresponds to the "switching unit."

[0080] In this embodiment, the switching valves V6, V7, V8, and V9 are three-way valves. The first heat medium circuit 30 is provided with a check valve V18 that prevents the first heat medium Q1 from flowing back to the radiator 37 and the exhaust heat utilization section 39. Although not shown, the first heat medium circuit 30 is provided with a check valve downstream of the condenser 49 that prevents the first heat medium Q1 from flowing back to the condenser 49.

[0081] In the first heat medium circuit 30 of this embodiment, the first heat medium Q1 cooled (heat dissipated) by the radiator 37 is sent to the first heat medium circuit 30 by the first heat medium pump 36, and absorbs heat from the inverter module INV and the power supply module PWR in the cooling unit 38. When the oil temperature is in the first temperature range D1, the first heat medium circuit 30 and the oil circuit 55 are switched by the switching valves V6 and V9 so that the oil passes through the first heat exchanger 31. When the oil temperature is in the second temperature range D2, the first heat medium circuit 30 and the oil circuit 55 are switched by the switching valves V6 and V9 so that the oil passes through the second heat exchanger 32.

[0082] The first heat medium Q1, whose temperature has risen in the first heat exchanger 31 or the second heat exchanger 32, passes through the switching valve V8 and returns to the radiator 37, where heat is dissipated. However, when utilizing exhaust heat in cold weather or when performing rapid heating using the vehicle air conditioner, heat dissipation by the radiator 37 is not necessary. In such cases, the switching valve V8 switches the first heat medium circuit 30 so that the first heat medium Q1 circulates without passing through the radiator 37.

[0083] In the first heat medium circuit 30 of this embodiment, when the oil temperature is in the first temperature range D1, for example, the first heat medium Q1 heat-exchanged in the first heat exchanger 31 is flowed to the radiator 37. When the oil temperature is in the second temperature range D2, for example, the first heat medium Q1 heat-exchanged in the second heat exchanger 32 is flowed to the exhaust heat utilization section 39. As a result, for example, when the oil temperature is high, the first heat medium Q1 is circulated between the first heat exchanger 31 and the radiator 37, so that the oil OL can be efficiently cooled when the oil temperature is high. For example, when the air temperature and oil temperature are low, the first heat medium Q1 is circulated between the second heat exchanger 32 and the exhaust heat utilization section 39 without passing through the radiator 37, so that heat transfer from the oil OL to the first heat medium Q1 can be efficiently performed even from a state in which the oil temperature is low and the viscosity of the oil OL is high, and the temperature of the first heat medium Q1 for exhaust heat utilization can be quickly increased.

[0084] In this embodiment, the first heat medium Q1, the first heat medium circuit 30, and the first heat medium path in the second heat exchanger 32 are "cooling water", "cooling water circuit", and "cooling water path", respectively. Examples of the cooling water include antifreeze and water.

[0085] In the above-mentioned vehicle drive device 10, the switching mechanism (switching valve V6, switching valve V9) switches the oil circuit 55 so that the oil OL passes through the first heat exchanger 31 without passing through the second heat exchanger 32 when the oil temperature is equal to or higher than a switching temperature Tc set between the lower limit T1d of the first temperature range D1 and the upper limit T2u of the second temperature range D2, and switches the oil circuit 55 so that the oil OL passes through the second heat exchanger 32 without passing through the first heat exchanger 31 when the oil temperature is lower than the switching temperature Tc.

[0086] In this way, heat exchange can be performed using either the first heat exchanger 31 or the second heat exchanger 32, whichever has a larger amount of heat exchangeable energy depending on the oil temperature at each time. Therefore, heat exchange between the first heat medium Q1 and the oil OL can be efficiently performed both when the temperature of the oil OL is higher and lower than the switching temperature Tc.

[0087] In the above-mentioned vehicle drive device 10, the flow rate of oil OL flowing into the first heat exchanger 31 when the oil temperature is in the first temperature range D1 is greater than the flow rate of oil OL flowing into the second heat exchanger 32 when the oil temperature is in the second temperature range D2.

[0088] In this way, the range of flow rates flowing into each of the first heat exchanger 31 and the second heat exchanger 32 is determined to some extent depending on the oil temperature, making it easier to appropriately realize a configuration in which the amount of heat exchangeable energy in the first heat exchanger 31 is greater than that in the second heat exchanger 32 when the oil temperature is in the first temperature range, and the amount of heat exchangeable energy in the second heat exchanger 32 is greater than that in the first heat exchanger 31 when the oil temperature is in the second temperature range D2, as described above.

[0089] In the vehicle drive device 10, the first heat medium circuit 30 is provided with a radiator 37 that exchanges heat between the first heat medium Q1 and the outside air, an exhaust heat utilization section 39 that utilizes the heat of the first heat medium Q1, and a switching section (switching valve V8) that directs the first heat medium Q1 to either the radiator 37 or the exhaust heat utilization section 39.

[0090] In this way, the circulation path of the first heat medium Q1 in the first heat medium circuit 30 can be switched between a circulation path that cools the oil OL using the first heat medium Q1 cooled by the radiator 37 and a circulation path that uses the heat of the first heat medium Q1 warmed by the oil OL. In addition, the temperature of the oil OL can be easily kept within a certain range. For example, by circulating the first heat medium Q1 between the first heat exchanger 31, which has a large amount of heat exchangeable energy when the oil temperature is high, and the radiator 37, the oil OL can be efficiently cooled when the oil temperature is high. In addition, for example, by circulating the first heat medium Q1 between the second heat exchanger 32, which has a large amount of heat exchangeable energy when the oil temperature is low, and the exhaust heat utilization section 39, the heat transfer from the oil OL to the first heat medium Q1 can be efficiently performed even from a state in which the oil temperature is low and the viscosity of the oil OL is high, and the temperature of the first heat medium Q1 for exhaust heat utilization can be rapidly increased.

[0091] The vehicle drive device 10 further includes an inverter module INV for driving and controlling the rotating electric machine MG, and the case 20 includes, in addition to a first accommodation chamber E1 as an accommodation chamber, a second accommodation chamber E2 in which the inverter module INV is accommodated, and a partition wall 28 that partitions the first accommodation chamber E1 and the second accommodation chamber E2. A third heat exchanger (cooling unit 38) that performs heat exchange between the inverter module INV and the first heat medium Q1 is provided upstream of the first heat exchanger 31 and the second heat exchanger 32 in the first heat medium circuit 30, and the first heat exchanger 31 is disposed in the second accommodation chamber E2, and the second heat exchanger 32 is formed in the partition wall 28.

[0092] In this way, the first heat medium circuit 30 is not arranged in the first accommodation chamber E1 in which the rotating electric machine MG serving as a heat source is arranged, or the section in which the first heat medium circuit 30 is arranged in the first accommodation chamber E1 can be easily shortened. Therefore, the temperature of the first heat medium Q1 before heat exchange with the oil OL can be easily kept low. In addition, since the second heat exchanger 32 is formed in the partition wall 28, it is easier to shorten the first heat medium circuit 30 and the oil circuit 55 and to reduce the size of the vehicle drive device 10 compared to a case in which the second heat exchanger 32 is arranged in a location other than the partition wall 28.

[0093] Other embodiments Next, other embodiments of the vehicle drive device 10 will be described.

[0094] (1) In the above embodiment, the heat exchanger for exchanging heat between the first heat medium Q1 and the oil OL is the first heat exchanger 31 and the second heat exchanger 32. However, the present invention is not limited to such an example, and may be configured to have three or more heat exchangers for exchanging heat between the first heat medium Q1 and the oil OL. In addition, the present invention may be configured to include an oil cooler configured to have a larger amount of heat exchangeable energy than the first heat exchanger 31 and the second heat exchanger 32 when the oil temperature is in a third temperature range D3 higher than the first temperature range D1, and the switching mechanism may be configured to switch the first heat medium circuit 30 and the oil circuit 55 so that the oil OL and the first heat medium Q1 pass through the oil cooler without passing through the first heat exchanger 31 and the second heat exchanger 32 when the oil temperature is equal to or higher than a second switching temperature set between the upper limit T1u of the first temperature range D1 and the lower limit T3d of the third temperature range D3.

[0095] (2) In the above embodiment, the flow rate F1 when the oil temperature is in the first temperature range D1 is greater than the flow rate F2 when the oil temperature is in the second temperature range D2. However, the present invention is not limited to such an example, and for example, the flow rate F1 when the oil temperature is at the lower limit T1d of the first temperature range D1 may be less than the flow rate F2 when the oil temperature is at the upper limit T2u of the second temperature range D2.

[0096] (3) In the above embodiment, a configuration has been described in which the first heat medium circuit 30 is provided with a switching valve V8 that causes the first heat medium Q1 to flow to either the radiator 37 or the exhaust heat utilization section 39. However, the present invention is not limited to such an example, and for example, the first heat medium circuit 30 may not be provided with the radiator 37 or the exhaust heat utilization section 39. Furthermore, for example, in a configuration in which the condenser 49 is used as the exhaust heat utilization section, the switching valve V7 may not be provided in the first heat medium circuit 30. Furthermore, for example, check valves such as the check valves V16 to V19 may not be provided in the first heat medium circuit 30 or the oil circuit 55.

[0097] (4) In the above embodiment, a configuration has been described in which the case 20 includes the partition wall 28, and the cooling unit 38 is provided upstream of the first heat exchanger 31 and the second heat exchanger 32 in the first heat medium circuit 30. However, the present invention is not limited to such an example, and may be configured, for example, such that the cooling unit 38 is provided downstream of the first heat exchanger 31 and the second heat exchanger 32. The vehicle drive device 10 may not include the inverter module INV. The case 20 may not include the partition wall 28 and the second accommodation chamber E2.

[0098] (5) In the above embodiment, the switching valve V6 switches the first heat medium circuit 30 so that the first heat medium Q1 does not pass through the second heat exchanger 32 but passes through the first heat exchanger 31 when the oil temperature is equal to or higher than the switching temperature Tc, and switches the first heat medium circuit 30 so that the first heat medium Q1 does not pass through the first heat exchanger 31 but passes through the second heat exchanger 32 when the oil temperature is lower than the switching temperature Tc. However, the present invention is not limited to such an example, and the switching mechanism may not include the switching valve V6, and the first heat medium circuit 30 may be configured so that the first heat medium Q1 flows through both the first heat exchanger 31 and the second heat exchanger 32 in the first temperature range D1 and the second temperature range D2.

[0099] (6) In the above embodiment, the power transmission mechanism GT is described as including the reduction gear 16 and the differential gear mechanism 15. However, the present invention is not limited to such an example, and may be configured such that the power transmission mechanism GT does not include the reduction gear 16 and includes only the differential gear mechanism 15. For example, the power transmission mechanism GT may include only the reduction gear 16 and does not include the differential gear mechanism 15, and may transmit power from one rotating electric machine MG to one wheel. For example, the reduction gear 16 may not be a planetary gear mechanism with a fixed gear ratio, and the reduction gear 16 may be a reduction mechanism with a multiple-stage gear ratio. For example, the power transmission mechanism GT may not be a single-shaft configuration, and may be a multiple-shaft configuration such as a two-shaft or three-shaft configuration.

[0100] (7) In the above embodiment, a configuration has been described in which the first member 81 and the second member 82 forming the second heat exchanger 32 are attached to the partition wall first surface 28a, which is the surface of the partition wall 28 facing the second storage chamber E2. However, without being limited to such an example, for example, the first member 81 and the second member 82 may be attached to the inner surface of the circumferential wall portion 26 or the inner surface of the cylindrical circumferential wall portion 27. Also, for example, the first member 81 and the second member 82 may be attached to the outer surface of the circumferential wall portion 26 or the outer surface of the cylindrical circumferential wall portion 27.

[0101] (8) The configurations disclosed in the above-described embodiments can be applied in combination with configurations disclosed in other embodiments, as long as no contradiction occurs. As for other configurations, the embodiments disclosed in this specification are merely examples in all respects. Therefore, various modifications can be made as appropriate within the scope of the present disclosure. [Explanation of symbols]

[0102] 8: vehicle, 10: vehicle drive device, 20: case, 28: partition wall, 30: first heat medium circuit (heat medium circuit), 31: first heat exchanger, 32: second heat exchanger, 38: cooling unit (third heat exchanger), 37: radiator, 39: exhaust heat utilization section, 49: condenser (exhaust heat utilization section), 55: oil circuit, E1: first housing chamber, E2: second housing chamber, GT: power transmission mechanism, INV: inverter module, MG: rotating electric machine, OL: oil, Q1: first heat medium (heat medium), V6: switching valve (switching mechanism), V7: switching valve (switching section), V8: switching valve (switching section), V9: switching valve (switching mechanism), W1: wheel, W2: wheel

Claims

1. A rotating electric machine; An output member drivingly connected to the wheels; a power transmission mechanism that transmits power between the rotating electric machine and the output member; a case including the rotating electric machine, the power transmission mechanism, and an accommodation chamber that accommodates oil; a heat medium circuit in which a heat medium circulates; an oil circuit through which the oil circulates; A vehicle drive device comprising: A first heat exchanger for exchanging heat between the heat medium and the oil; A second heat exchanger that performs heat exchange between the heat medium and the oil; A switching mechanism for switching the oil circuit; Further comprising: the first heat exchanger is configured to have a larger amount of heat exchangeable energy than the second heat exchanger when an oil temperature, which is a temperature of the oil, is within a predetermined first temperature range; the second heat exchanger is configured to have a larger amount of heat exchangeable energy than the first heat exchanger when the oil temperature is in a second temperature range that is lower than the first temperature range; The switching mechanism includes: When the oil temperature is equal to or higher than a switching temperature set between a lower limit of the first temperature range and an upper limit of the second temperature range, the oil circuit is switched so that the oil does not pass through the second heat exchanger but passes through the first heat exchanger; When the oil temperature is lower than the switching temperature, the oil circuit is switched so that the oil does not pass through the first heat exchanger but passes through the second heat exchanger.

2. 2. The vehicle drive device according to claim 1, wherein a flow rate of the oil flowing into the first heat exchanger when the oil temperature is in the first temperature range is greater than a flow rate of the oil flowing into the second heat exchanger when the oil temperature is in the second temperature range.

3. 3. The vehicle drive device according to claim 1, wherein the heat medium circuit is provided with a radiator that performs heat exchange between the heat medium and outside air, a waste heat utilization unit that utilizes heat of the heat medium, and a switching unit that causes the heat medium to flow to either the radiator or the waste heat utilization unit.

4. further comprising an inverter module for driving and controlling the rotating electric machine; the case includes, in addition to a first accommodation chamber as the accommodation chamber, a second accommodation chamber in which the inverter module is accommodated, and a partition wall that partitions the first accommodation chamber and the second accommodation chamber, a third heat exchanger that exchanges heat between the inverter module and the heat medium is provided upstream of the first heat exchanger and the second heat exchanger in the heat medium circuit; The first heat exchanger is disposed in the second chamber, The vehicle drive device according to claim 1 or 2, wherein the second heat exchanger is formed in the partition wall.

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