Cooling circuit module

Abstract

To appropriately achieve overall heat management depending on vehicle's various operation states.SOLUTION: A cooling circuit module 1 comprises: a cooling water inflow port 10; an outflow port 30; a cooling water passage 20 which is connected to a first heat exchanger 71 and a second heat exchanger 72, and in which cooling water flows; and a plurality of selector valves V. The cooling circuit module is so configured as to be capable of being switched between a first mode and one of a second mode and a third mode, the first mode in which a first path from the inflow port 10 to the outflow port 30 via the first heat exchanger 71 and the second heat exchanger 72 is formed, the second mode in which a second path from the inflow port 10 to the outflow port 30 via the first exchanger 71 and a first circulation path passing the second heat exchanger 72 are formed, and the third mode in which a third path directly connecting the inflow port 10 and the outflow port 30 and a second circulation path passing the first heat exchanger 71 and the second heat exchanger 72 are formed.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a cooling circuit module mounted on a vehicle drive device.

Background Art

[0002] In recent years, electric vehicles (including series hybrid vehicles) using a rotating electric machine as a driving power source for wheels have been increasing. In conventional vehicles using an internal combustion engine as a driving power source for the vehicle, the heat generated from the internal combustion engine could be used for warming up power transmission mechanisms such as gears and bearings, and as a heat source for heating the vehicle interior. However, in electric vehicles, it is difficult to utilize the exhaust heat of the internal combustion engine, and there is a tendency for a shortage of heat sources. Japanese Unexamined Patent Application Publication No. 2019-22374 describes a technique for warming up a power transmission mechanism while charging an in-vehicle battery, which is a power source in an electric vehicle, with an external power source. Specifically, during charging of the in-vehicle battery, part of the power supplied from the external power source is used to generate heat in an inverter that drives a rotating electric machine, the heat is stored in oil that lubricates the power transmission mechanism, and the power transmission mechanism is warmed up by the warmed oil. At this time, the cooling water circuit is switched so that the coolant does not pass through the radiator, and the inverter is also driven in a switching control method in which the loss is larger and the heat generation is larger than when driving the wheels.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The warm-up described above is carried out under limited conditions where the vehicle is parked and the in-vehicle battery is being charged. However, not only for warm-up, for example, heat is also required for heating the vehicle interior while the vehicle is running. Some electric vehicles are equipped with a separate heater as a heat source, but this will consume the power of the in-vehicle battery. Therefore, it is desirable to appropriately utilize heat while maintaining high energy efficiency according to various operating conditions of the vehicle, such as during charging, warm-up at vehicle startup, and heating during running.

[0005] In view of the above background, it is desirable to appropriately achieve comprehensive heat management according to various operating conditions of the vehicle.

Means for Solving the Problem

[0006] A cooling circuit module mounted on a vehicle drive device including at least a power circuit module in which a rotating electric machine serving as a driving force source for wheels, a power transmission mechanism for transmitting power between the wheels and the rotating electric machine, and a rotating electric machine drive circuit for driving the rotating electric machine are formed, An inlet through which cooling water flows in, An outlet through which the cooling water flows out, A first heat exchanger for heat exchange between the power circuit module and the cooling water, and a cooling water passage through which the cooling water flows, connected to a second heat exchanger for heat exchange between oil for cooling the rotating electric machine and lubricating the power transmission mechanism and the cooling water, A plurality of switching valves for switching the cooling water passage, and By changing the states of the plurality of switching valves, the cooling water passage A first mode in which a first path from the inlet through the first heat exchanger and the second heat exchanger to the outlet is formed, A second mode in which a second path from the inlet through the first heat exchanger to the outlet and a first circulation path for circulating a closed circuit through the second heat exchanger are formed, A third mode in which a third path directly connecting the inlet and the outlet and a second circulation path for circulating a closed circuit through the first heat exchanger and the second heat exchanger are formed, Among them, it is configured to be switchable at least between the first mode and at least one of the second mode and the third mode.

[0007] According to this configuration, in the first mode, a first path is formed from the inlet through both the first heat exchanger and the second heat exchanger to the outlet, so that heat exchange between the power circuit module and the cooling water, and heat exchange between the oil and the cooling water can be performed. Therefore, in the first mode, both the power circuit module and the power transmission mechanism can be appropriately cooled. In the second mode, a second path is formed from the inlet through the first heat exchanger to the outlet, so that heat exchange between the power circuit module and the cooling water can be performed. Also, in the second mode, a first circulation path, which is a closed circuit passing through the second heat exchanger, is formed, so that heat can be stored in the cooling water. Therefore, in the second mode, for example, heat can be received from the first heat exchanger and the heat of the cooling water flowing out from the outlet can be utilized inside the vehicle. Also, for example, the power transmission mechanism can be easily warmed up by the heat accumulated in the cooling water flowing through the first circulation path. In the third mode, a second circulation path, which is a closed circuit passing through the first heat exchanger and the second heat exchanger, is formed, so that heat can be stored in the cooling water. Therefore, in the third mode, for example, heat can be received from the first heat exchanger and the power transmission mechanism can be easily warmed up. Also, since the inlet and the outlet are directly connected by the third path, the flow of the cooling water in the vehicle is not obstructed, and the cooling water is appropriately utilized inside the vehicle. According to this configuration, in addition to the first mode, at least one of the second mode and the third mode can be realized. Therefore, appropriate comprehensive heat management can be realized according to various operating conditions of the vehicle.

[0008] Further features and advantages of the cooling circuit module will become clear from the following description of exemplary and non-limiting embodiments with reference to the drawings.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of the cooling circuit module will be described with reference to the drawings. The schematic diagram of FIG. 1 shows an example of a vehicle drive device 100 equipped with a cooling circuit module 1. The cooling circuit module 1 of the present embodiment is mounted on a vehicle drive device 100 in which a power circuit module 3 in which a power circuit including at least a rotating electric machine MG serving as a driving force source for the wheel W, a power transmission mechanism TA for transmitting power between the wheel W and the rotating electric machine MG, and a rotating electric machine drive circuit INV for driving the rotating electric machine MG is formed. That is, in the present embodiment, the vehicle drive device 100 is configured to include the cooling circuit module 1.

[0011] The rotating electric machine MG is an AC rotating electric machine, and in this embodiment, it is a three-phase AC type rotating electric machine as shown in FIG. 2. The power circuit module 3 includes a rotating electric machine drive circuit INV that drives the rotating electric machine MG. The rotating electric machine drive circuit INV is configured with switching elements and includes, for example, an inverter that converts electric power between an in-vehicle battery (high-voltage battery BH) with a rated voltage of direct current from 200 to 800 volts and the AC rotating electric machine MG. The switching elements are power transistors such as IGBT (Insulated Gate Bipolar Transistor), power MOSFET (Metal Oxide Semiconductor Field Effect Transistor), and HEMT (High Electron Mobility Transistor). The rotating electric machine MG is driven and controlled by a rotating electric machine control device (integrated control device 8) based on the target torque of the rotating electric machine MG set according to a command from a vehicle control device (not shown). The rotating electric machine control device performs switching control on a plurality of switching elements to cause the rotating electric machine drive circuit INV to convert electric power between direct current and alternating current of a plurality of phases (three phases in this embodiment).

[0012] Incidentally, the operating voltage of the rotating electric machine control device configured with an electronic circuit as the core is about 3.3 volts to 5 volts, but the voltage of the switching control signal of the power transistor requires about 15 volts to 24 volts. Therefore, between the rotating electric machine control device and the power transistor, there is provided a driver that amplifies the voltage amplitude of the switching control signal output from the rotating electric machine control device and increases the driving force to supply it to the power transistor. This driver may be included in the integrated control device 8 described later together with the rotating electric machine control device, or may be included in the rotating electric machine drive circuit INV.

[0013] The rotating electrical machine MG has a function as a motor (electric motor) that generates power by receiving power supply from the high-voltage battery BH, and a function as a generator (alternator) that generates power by receiving power supply from the side of the wheel W. That is, the rotating electrical machine MG generates a driving force by traveling with the power stored in the high-voltage battery BH, and generates electricity by the driving force transmitted from the side of the pair of wheels W to charge the high-voltage battery BH. The high-voltage battery BH is composed of, for example, a rechargeable secondary battery such as a lithium-ion battery, or an electric double layer capacitor.

[0014] In the present embodiment, the high-voltage battery BH is configured to be chargeable not only by the power generated by the rotating electrical machine MG, but also by the power supplied to the vehicle from an external power source. The external power source may be a DC dedicated power source, or an AC commercial power source with a rated (effective value) of about 100 volts to 240 volts. The vehicle is equipped with an on-vehicle charging circuit OBC (Onboard Charger) that charges the high-voltage battery BH with the power supplied from the external power source in a state where the high-voltage battery BH is mounted on the vehicle. The external power source and the on-vehicle charging circuit OBC may be in a form of being wired-connected by, for example, a connector, or in a form where power is supplied to the on-vehicle charging circuit OBC from the external power source non-contact by electromagnetic induction or the like. The on-vehicle charging circuit OBC is configured to include a power conversion circuit such as an AC-DC converter or a DC-DC converter configured using a power transistor such as an IGBT, a power MOSFET, or a HEMT. This power conversion circuit is controlled by an OBC control device (integrated control device 8).

[0015] In addition, the on-vehicle charging circuit OBC may be configured to be able to output an alternating current with a rated voltage of 100 volts to 200 volts to an AC power socket (alternating current power socket) for supplying power to general household appliances or the like by performing power conversion in the reverse direction to the charging time. In this case, the on-vehicle charging circuit OBC functions as both a charging circuit for charging the high-voltage battery BH from an external AC power source and a power supply circuit for supplying power from the high-voltage battery BH to the outside.

[0016] Also, although not shown in FIG. 2, the high-voltage battery BH may supply driving power not only to the rotating electrical machine MG but also to auxiliary machines with relatively high power consumption, such as an air conditioner (e.g., a compressor), an oil pump, and a water pump.

[0017] Also, in the present embodiment, the high-voltage battery BH supplies power to a low-voltage battery BL having a rated voltage of about 12 volts to 24 volts. The low-voltage battery BL serves as a power source for vehicle headlights, power windows, power steering, and various control devices inside the vehicle. The low-voltage battery BL may be a rechargeable secondary battery such as a lithium-ion battery or an electric double-layer capacitor, but may also be a lead-acid battery, similar to a conventional vehicle having an internal combustion engine as a driving power source.

[0018] Conventionally, such a low-voltage battery BL has been charged by electric power generated by an alternator interlocked with a driving power source of the vehicle (e.g., an internal combustion engine). However, in the present embodiment, the low-voltage battery BL is configured to be charged via a step-down converter BC (Buck Convertor) by electric power from the high-voltage battery BH having a higher voltage and a larger power storage capacity than the low-voltage battery BL. This eliminates the need to install an alternator and also suppresses power loss of the driving power source of the vehicle (in this embodiment, the rotating electrical machine MG) associated with driving the alternator. It is preferable that the high-voltage battery BH and the low-voltage battery BL are electrically insulated, and the step-down converter BC is preferably configured by an insulated circuit including a power transistor and a transformer. The step-down converter BC is controlled by a step-down converter control device (integrated control device 8).

[0019] In this embodiment, a power distribution unit PDU (Power Delivery Unit) is configured to include an on-vehicle charging circuit OBC and a buck converter BC. And a power circuit module 3 is configured to include the power distribution unit PDU and a rotating electrical machine drive circuit INV. As shown in FIG. 2, the power circuit module 3 may also include a DC link capacitor C (smoothing capacitor) that smooths the voltage on the DC side of the inverter, that is, the DC link voltage which is the output voltage of the high-voltage battery BH. Note that, for the sake of convenience, FIG. 2 shows the low-voltage battery BL as being included in the power distribution unit PDU. However, similar to the high-voltage battery BH, the low-voltage battery BL is also arranged at a location separate from the power distribution unit PDU and the power circuit module 3, that is, separate from the vehicle drive device 100.

[0020] The on-vehicle charging circuit OBC, the buck converter BC, and the rotating electrical machine drive circuit INV are power circuits. It is preferable that a rotating electrical machine control device, an OBC control device, and a buck converter control device for controlling each circuit are also formed on the same substrate, for example, as an integrated control device 8. It is also preferable that the integrated control device 8 is provided in the vehicle drive device 100. The power circuit module 3 may be configured to include the integrated control device 8, or the integrated control device 8 may be arranged above the power circuit module 3 (on the side opposite to the cooling unit 71 described later) in the form illustrated in FIG. 1.

[0021] Switching elements such as power transistors in the power circuit module 3 generate heat because a large current flows through them. Also, the DC link capacitor C that smooths the DC voltage that generates ripples also generates heat due to the inflow and outflow of current. Therefore, in this embodiment, the power circuit module 3 is provided with a cooling unit 71 through which cooling water for cooling heat-generating parts such as the heat-generating circuit in the power circuit module 3 flows. The cooling unit 71 is configured as a water jacket (WJ) through which the cooling water circulates, and is a heat exchanger (first heat exchanger) that exchanges heat between the power circuit module 3 and the cooling water.

[0022] Further, the cooling unit 71 may be in contact with, for example, a power module in which a plurality of power transistors are integrated to perform heat exchange with the power module, or may be in a form of receiving heat indirectly from the power module through a heat conductor such as oil or a heat sink member to perform heat exchange.

[0023] As shown in FIG. 1, the vehicle drive device 100 includes, as a power unit 4 for driving the wheel W, a rotating electric machine MG that serves as a driving force source for the wheel W, and a power transmission mechanism TA that transmits power between the wheel W and the rotating electric machine MG. The power transmission mechanism TA is configured to have a plurality of gears. For example, the power transmission mechanism TA includes a speed reducer that reduces the rotation of the rotor of the rotating electric machine MG and transmits it to the wheel W side, and a differential gear mechanism that distributes power to a pair of wheels W. FIG. 1 illustrates a power unit 4 in which the rotation axis of the rotor of the rotating electric machine MG and the rotation axis of the wheel W are separate axes. Although two axes are simply shown, a configuration with three or more axes may be used. Further, it may be a single-axis configuration in which all the rotation axes of the power unit 4 include the rotation axis of the rotor and the rotation axis of the wheel W and are coaxial. Further, the power unit 4 may be in a form of driving one wheel W without including a differential gear mechanism for distributing power to a pair of wheels W. Further, the power transmission mechanism TA may be configured only by a shaft member and a bearing without including a gear mechanism such as a speed reducer.

[0024] A large current flows through the coil of the rotating electric machine MG (including the rotor field coil in the case of a wound field synchronous rotating electric machine (EESM)), so it generates heat. For this reason, the coil is cooled by the oil in the case of the power unit 4. Also, bearings that rotatably support rotating members in the power unit 4, such as a rotor shaft that supports the rotor and rotates integrally with the rotor, and meshing portions between gears that transmit power are also lubricated with oil. In order to maintain the cooling effect of the oil that rises due to heat generation by current and frictional heat, the oil is cooled by an oil cooler 72 (OC). The oil cooler 72 is a heat exchanger (second heat exchanger) that performs heat exchange between cooling water and oil.

[0025] The cooling water is subjected to heat exchange in the cooling unit 71 as the first heat exchanger and the oil cooler 72 as the second heat exchanger. Therefore, for example, as illustrated in FIG. 1, in the vehicle drive device 100, a cooling circuit module 1 is provided in which a cooling water passage 20 (see FIGS. 3 to 6) through which the cooling water flows is formed between the cooling unit 71 and the oil cooler 72. FIG. 3 shows an example of the cooling circuit diagram of the cooling circuit module 1. The cooling circuit module 1 includes an inlet 10 into which the cooling water flows, an outlet 30 from which the cooling water flows out, a cooling water passage 20 that is connected to the cooling unit 71 (WJ) as the first heat exchanger and the oil cooler 72 (OC) as the second heat exchanger and through which the cooling water flows, and a plurality of switching valves V that switch the cooling water passage 20.

[0026] Although details will be described later, the cooling circuit module 1 is configured such that the cooling water passage 20 can be switched between a first mode (MD1) and a second mode (MD2), or between the first mode (MD1) and a third mode (MD3), or between the first mode (MD1), the second mode (MD2), and the third mode (MD3) by changing the state of the switching valve V. That is, the cooling circuit module 1 is configured such that the cooling water passage 20 can be switched between at least the first mode and at least one of the second mode and the third mode. The state of the switching valve V is controlled by, for example, a cooling circuit module control device included in the integrated control device 8.

[0027] As shown in FIG. 4, the first mode is a mode in which a first path 21 extending from the inlet 10 through the cooling unit 71 and the oil cooler 72 to the outlet 30 is formed. As shown in FIG. 5, the second mode is a mode in which a second path 22 extending from the inlet 10 through the cooling unit 71 to the outlet 30 and a first circulation path 25 that circulates through a closed circuit passing through the oil cooler 72 are formed. As shown in FIG. 6, the third mode is a mode in which a third path 23 directly connecting the inlet 10 and the outlet 30 and a second circulation path 26 that circulates through a closed circuit passing through the cooling unit 71 and the oil cooler 72 are formed.

[0028] In this embodiment, a form in which the cooling water channel 20 is configured to be switchable among a first mode, a second mode, and a third mode will be described as an example. The cooling circuit module 1 includes a first connection part 11 connected to the supply port of the cooling water to the cooling unit 71, a second connection part 12 connected to the discharge port of the cooling water from the cooling unit 71, a third connection part 13 connected to the supply port of the cooling water to the oil cooler 72, and a fourth connection part 14 connected to the discharge port of the cooling water from the oil cooler 72. Further, the cooling circuit module 1 includes a water pump WP (pump) for circulating the cooling water. The water pump WP includes a first suction port 31, a second suction port 32, a first discharge port 41, and a second discharge port 42. The cooling water sucked from the first suction port 31 is discharged from the first discharge port 41, and the cooling water sucked from the second suction port 32 is discharged from the second discharge port 42. The water pump WP is also controlled by a cooling circuit module control device included in the integrated control device 8.

[0029] The cooling circuit module 1 includes a first valve V1, a second valve V2, and a third valve V3 as a plurality of switching valves. In the water pump WP, the first discharge port 41 is connected to the third connection part 13, the second discharge port 42 is connected to the first valve V1, and the first suction port 31 and the second suction port 32 are connected to the fourth connection part 14 via the third valve V3.

[0030] The first valve V1 is switchable between a first state (ST1) and a second state (ST2). The first state (ST1) is a state in which the inlet 10 and the first connection part 11 are connected, and the second state (ST2) is a state in which the inlet 10 and the outlet 30 are connected and the first connection part 11 and the second discharge port 42 are connected. The second valve V2 is switchable between a third state (ST3) and a fourth state (ST4). The third state (ST3) is a state in which the second connection part 12 and the third connection part 13 are connected, and the fourth state (ST4) is a state in which the second connection part 12 and the outlet 30 are connected. The third valve V3 is switchable between a fifth state (ST5), a sixth state (ST6), and a seventh state (ST7). The fifth state (ST5) is a state in which the fourth connection part 14 and the outlet 30 are connected, the sixth state (ST6) is a state in which the fourth connection part 14 and the first suction port 31 are connected, and the seventh state (ST7) is a state in which the fourth connection part 14 and the second suction port 32 are connected.

[0031] As described above, in the present embodiment, the cooling circuit module 1 is configured such that the cooling water passage 20 is switchable between a first mode (MD1), a second mode (MD2), and a third mode (MD3). In the first mode (MD1), the first valve V1 is switched to the first state (ST1), the second valve V2 is switched to the third state (ST3), and the third valve (V3) is switched to the fifth state (ST5). In the second mode (MD2), the first valve V1 is switched to the first state (ST1), the second valve V2 is switched to the fourth state (ST4), and the third valve V3 is switched to the sixth state (ST6). In the third mode (MD3), the first valve V1 is switched to the second state (ST2), the second valve V2 is switched to the third state (ST3), and the third valve (V3) is switched to the seventh state (ST7). That is, the cooling water passage 20 is configured to be switchable between three modes as shown in Table 1 below.

[0032]

Table 1

[0033] Each mode is determined by the integrated control device 8 (cooling circuit module control device) based on the outside air temperature, oil temperature, coolant temperature, temperature of the power circuit module 3 (especially the inverter temperature), temperature of the rotating electrical machine MG, etc. Each temperature is detected by a temperature sensor (not shown), and the detection result is transmitted to the integrated control device 8.

[0034] Hereinafter, the situations in which each mode is selected will also be illustrated and described. Each mode is selected in consideration of the temperature suitable for each device included in the vehicle drive device 100. Further, each mode is selected in consideration of the demand (heat demand) in the device to which the coolant is supplied outside the cooling circuit module 1. That is, the cooling circuit module 1 is configured to achieve both reduction of the loss inside the vehicle drive device 100 on which the cooling circuit module 1 is mounted and supply of heat to the outside of the vehicle drive device 100 by switching the path of the coolant flowing through the internal cooling water passage 20.

[0035] Here, a supplement is made regarding the relationship between the loss and temperature inside the vehicle drive device 100. In the power circuit module 3 (especially the inverter), the lower the temperature of elements such as power transistors, the higher the efficiency due to the acceleration of electron movement, the reduction of the internal resistance of the elements, etc. Further, since the power circuit module 3 also has good thermal conductivity to the cooling unit 71, it can transfer heat to the coolant with high efficiency. In the magnetic circuit of the rotating electrical machine MG, the lower the temperature, the higher the magnetic performance of the permanent magnet and the lower the copper loss in the coil. In the power transmission mechanism TA, at low temperatures, the viscosity of the oil increases, resulting in an increase in the resistance to rotation and a tendency for the loss to increase. From the perspective of lubrication, warming the oil to reduce its viscosity is suitable for reducing so-called drag loss.

[0036] As described above, each mode is selected in consideration of the demand (heat demand) in the device to which the cooling water is supplied outside the cooling circuit module 1. FIG. 7 illustrates a heat exchanger (external heat exchanger) connected to the cooling water passage outside the cooling circuit module 1. Here, the cooling water passage through which the cooling water flowing into the inlet 10 of the cooling circuit module 1 flows is referred to as the first external passage 51, and the passage through which the cooling water flowing out from the outlet 30 flows is referred to as the second external passage 53. The external heat exchanger is disposed on at least one side of the first external passage 51 and the second external passage 53. Note that the external heat exchanger does not necessarily have to be directly connected to the first external passage 51 or the second external passage 53, and may be connected via another external heat exchanger or the like. Also, the external heat exchanger may be disposed at an equivalent position with respect to the first external passage 51 and the second external passage 53.

[0037] In the present embodiment, as the external heat exchanger, a radiator 55 (third heat exchanger), a chiller 56 (fourth heat exchanger), and a battery cooler 57 (fifth heat exchanger) are illustrated. Here, a form in which the radiator 55, the chiller 56, and the battery cooler 57 are connected in series to the external passage is illustrated, but all or any of these may be connected in parallel. Also, in the present embodiment, three-way valves are connected in series to the respective external heat exchangers, and the cooling water is configured to be able to flow around the respective external heat exchangers. The flow direction of each three-way valve may be controlled by the integrated control device 8, or may be automatically controlled by a valve, for example, provided with a thermostat or the like.

[0038] The radiator 55 is a heat exchanger that performs heat exchange between the outside air and the cooling water, and cools the cooling water by heat exchange between the cooling water whose temperature has risen by heat exchange with the heat generating device and the outside air. When heat exchange with the outside air is unnecessary, such as when the temperature of the cooling water is sufficiently low, the flow path is switched by the three-way valve V55 for the radiator so that the cooling water flows around the radiator 55.

[0039] The chiller 56 is a heat exchanger connected to the refrigerant flow path 60 through which the refrigerant of the air conditioner 6 flows, and performs heat exchange between the refrigerant of the air conditioner 6 and the cooling water during heating. The chiller 56 heats the refrigerant by heat exchange between the cooling water whose temperature has risen by heat exchange with the heat-generating device and the refrigerant. In the air conditioner 6, heat exchange is performed between the heated refrigerant and the air supplied from the fan in a cabin condenser (not shown), and warm air is supplied into the vehicle interior. When heating is not required, the flow path is switched by the three-way valve V56 for the chiller so that the cooling water flows around the chiller 56. Alternatively, the refrigerant flow path 60 may be switched so that the refrigerant flows around the chiller 56.

[0040] The battery cooler 57 is a heat exchanger that performs heat exchange with the high-voltage battery BH. The battery cooler 57 cools the high-voltage battery BH that generates heat due to a large current flowing, such as when the vehicle is running with the rotation electric machine MG driven, by the cooling water. Further, since the power storage performance and the power supply performance of the high-voltage battery BH decrease at low temperatures, when the ambient temperature is low, the high-voltage battery BH is warmed by heat exchange with the cooling water that has risen to a temperature higher than that of the high-voltage battery BH by heat exchange with the heat-generating device. When warming and cooling of the high-voltage battery BH are not required, the flow path is switched by the three-way valve V57 for the battery cooler so that the cooling water flows around the battery cooler 57.

[0041] The first mode is the so-called normal mode, which is a normal cooling mode for cooling the power circuit module 3 and the oil. For example, when the outside air temperature is relatively high (generally 20 degrees Celsius or more, and there is no need for heating in the vehicle cabin), the temperature of the power circuit module 3 (especially the inverter) and the temperature of the rotating electrical machine MG are likely to rise (operation at high torque and high rotational speed), and when the power unit 4 is sufficiently warmed up, it is preferable to select the first mode. It is not necessary to satisfy all of these conditions. For example, the first mode may be selected when there is no need for heating or when the power unit 4 is sufficiently warmed up. As described above, the first mode is the normal mode, and when it is not necessary to utilize the heat of the cooling water, the first mode is selected.

[0042] The second mode is selected when (a) warming up the high-voltage battery BH or (b) assisting the heating capacity of the air conditioner 6. In either application of (a) or (b), the power unit 4 is warmed up by raising the temperature of the cooling water by the heat generated by the power unit 4 itself.

[0043] First, the case of (a) will be described. Since the high-voltage battery BH has reduced power storage performance and power supply performance at low temperatures, it is desirable to quickly warm up the high-voltage battery BH when starting the vehicle (when starting the vehicle drive device 100) in cases where the outside air temperature is low, such as in winter, to improve the system performance of the entire vehicle. The power circuit module 3, particularly the inverter, is likely to generate heat by passing a current through the switching element. On the other hand, the power unit 4 has a large amount of metal with high thermal conductivity and a larger heat capacity than the power circuit module 3. Therefore, the waste heat from the power circuit module 3 is likely to move to the power unit 4 via the oil cooler 72. To suppress a decrease in the heat provided to the high-voltage battery BH, the path of the cooling water passing through the oil cooler 72 is separated from the second path 22 as a closed circuit. The waste heat from the power circuit module 3 is supplied to the battery cooler 57 via the cooling unit 71 and the second path 22, and the high-voltage battery BH is warmed up. The power unit 4 is warmed up by raising the temperature of the cooling water circulating through the first circulation path 25 by the heat generated by the power unit 4 itself.

[0044] Next, the case of (b) will be described. In an electric vehicle in which the exhaust heat of the internal combustion engine cannot be used for heating, the heat pump system is often adopted as a heating method. When the outside air temperature is low, the heat transferred from the outside air to the refrigerant also decreases. Therefore, in the chiller 56, the heating capacity can be improved by transferring heat from the cooling water heated by the exhaust heat from the power circuit module 3 to the refrigerant. When the power unit 4 is warming up, if the temperature of the oil decreases in the oil cooler 72 due to the cooling water whose temperature has decreased via the chiller 56, it will hinder the warm-up. Also, if heat moves from the cooling water heated by the exhaust heat from the power circuit module 3 to the power unit 4 being warmed up via the oil cooler 72, it will prevent the improvement of the heating capacity. By separating the path of the cooling water passing through the oil cooler 72 as a closed circuit from the second path 22, the exhaust heat from the power circuit module 3 is supplied to the chiller 56 via the cooling unit 71 and the second path 22 and used for heating. The power unit 4 is warmed up by raising the temperature of the cooling water circulating through the first circulation path 25 by the heat generated by the power unit 4 itself.

[0045] In the second mode, it is not preferable for the temperature of the cooling water flowing through the second path 22 to move to the cooling water flowing through the first circulation path 25. Therefore, it is preferable that a heat insulation structure 59 is provided between the second path 22 and the first circulation path 25. The heat insulation structure 59 is, for example, an air layer or the arrangement of heat insulating materials.

[0046] The third mode is selected when, such as in spring or autumn, there is no need to warm up the high-voltage battery BH or for heating, but when starting the vehicle (vehicle drive device 100), etc., the oil temperature has not risen sufficiently and the loss in the power unit 4 is likely to increase. As described above, the power circuit module 3 (especially the inverter) is likely to generate heat by passing current through the switching elements. By forming a closed circuit via the cooling unit 71 and the oil cooler 72, it is easy to quickly warm up the power unit 4. By forming the third path 23 that directly connects the inlet 10 and the outlet 30, the flow of the cooling water flowing in the vehicle can be prevented from being obstructed by forming the second circulation path 26.

[0047] As described above, by using the cooling circuit module 1 of the present embodiment, appropriate comprehensive heat management can be realized according to various operating conditions of the vehicle.

[0048] Hereinafter, the cooling circuit module 1 according to the above-described present embodiment will be briefly summarized.

[0049] As one aspect, a cooling circuit module mounted on a vehicle drive device including at least a power circuit module in which a power circuit including a rotating electric machine serving as a driving force source for wheels, a power transmission mechanism for transmitting power between the wheels and the rotating electric machine, and a rotating electric machine drive circuit for driving the rotating electric machine is formed, an inlet through which cooling water flows, an outlet through which the cooling water flows out, a first heat exchanger that exchanges heat between the power circuit module and the cooling water, and a cooling water passage to which a second heat exchanger that exchanges heat between oil for cooling the rotating electric machine and lubricating the power transmission mechanism and the cooling water is connected and through which the cooling water flows, a plurality of switching valves for switching the cooling water passage, and by changing the states of the plurality of switching valves, the cooling water passage forms a first mode in which a first path from the inlet through the first heat exchanger and the second heat exchanger to the outlet is formed, A second path that extends from the inlet through the first heat exchanger to the outlet, and a second mode in which a first circulation path that circulates through a closed circuit passing through the second heat exchanger is formed. A third path that directly connects the inlet and the outlet, and a third mode in which a second circulation path that circulates through a closed circuit passing through the second heat exchanger and the first heat exchanger is formed. Among these, at least the first mode and at least one of the second mode and the third mode are configured to be switchable.

[0050] According to this configuration, in the first mode, a first path is formed that extends from the inlet through both the first heat exchanger and the second heat exchanger to the outlet, enabling heat exchange between the power circuit module and the cooling water, and heat exchange between the oil and the cooling water. Therefore, in the first mode, both the power circuit module and the power transmission mechanism can be appropriately cooled. In the second mode, a second path is formed that extends from the inlet through the first heat exchanger to the outlet, enabling heat exchange between the power circuit module and the cooling water. Also, in the second mode, a first circulation path, which is a closed circuit passing through the second heat exchanger, is formed, allowing heat to be stored in the cooling water. Therefore, in the second mode, for example, heat can be received from the first heat exchanger and the heat of the cooling water exiting the outlet can be utilized inside the vehicle. Also, for example, the power transmission mechanism can be easily warmed up by the heat accumulated in the cooling water flowing through the first circulation path. In the third mode, a second circulation path, which is a closed circuit passing through the first heat exchanger and the second heat exchanger, is formed, allowing heat to be stored in the cooling water. Therefore, in the third mode, for example, heat can be received from the first heat exchanger to easily warm up the power transmission mechanism. Also, since the inlet and the outlet are directly connected by the third path, the flow of the cooling water in the vehicle is not obstructed, and the cooling water is appropriately utilized inside the vehicle. According to this configuration, in addition to the first mode, at least one of the second mode and the third mode can be realized. Therefore, appropriate comprehensive heat management can be achieved according to various operating conditions of the vehicle.

[0051] Also, the cooling circuit module a first connection part connected to the supply port of the cooling water to the first heat exchanger; a second connection part connected to the discharge port of the cooling water from the first heat exchanger; a third connection part connected to the supply port of the cooling water to the second heat exchanger; a fourth connection part connected to the discharge port of the cooling water from the second heat exchanger; a pump for circulating the cooling water; the pump includes a first suction port, a second suction port, a first discharge port for discharging the cooling water sucked from the first suction port, and a second discharge port for discharging the cooling water sucked from the second suction port; the plurality of switching valves includes a first valve, a second valve, and a third valve; in the pump, the first discharge port is connected to the third connection part, the second discharge port is connected to the first valve, and the first suction port and the second suction port are connected to the fourth connection part via the third valve; the first valve: is switchable between a first state in which the inlet and the first connection part are connected; and a second state in which the inlet and the outlet are connected and the first connection part and the second discharge port are connected; the second valve: is switchable between a third state in which the second connection part and the third connection part are connected; and a fourth state in which the second connection part and the outlet are connected; the third valve: is switchable between a fifth state in which the fourth connection part and the outlet are connected; a sixth state in which the fourth connection part and the first suction port are connected; and a seventh state in which the fourth connection part and the second suction port are connected; in the first mode, the first valve is switched to the first state, the second valve is switched to the third state, and the third valve is switched to the fifth state; in the second mode, the first valve is switched to the first state, the second valve is switched to the fourth state, and the third valve is switched to the sixth state; In the third mode, it is preferable that the first valve is switched to the second state, the second valve is switched to the third state, and the third valve is switched to the seventh state.

[0052] According to this configuration, a plurality of switching valves and a pump can appropriately form a first path, a second path, a third path, a first circulation path, and a second circulation path to realize a first mode, a second mode, and a third mode.

[0053] Further, at least one of a third heat exchanger that performs heat exchange between the outside air and the cooling water, a fourth heat exchanger that performs heat exchange between the refrigerant of the air conditioner and the cooling water, and a fifth heat exchanger that performs heat exchange between the battery connected to the power circuit module and the cooling water is preferably disposed on at least one side of a first external flow path through which the cooling water flowing into the inlet flows and a second external flow path through which the cooling water flowing out from the outlet flows.

[0054] When the third heat exchanger is provided, the heat transferred to the cooling water in the cooling circuit module can be dissipated. When the fourth heat exchanger is provided, when the air conditioner performs heating, the heat transferred to the cooling water in the cooling circuit module can be used as a heat source. When the fifth heat exchanger is provided, the battery can be cooled by the cooling water, and when the battery is at a low temperature, the battery can be warmed up using the heat transferred to the cooling water in the cooling circuit module.

[0055] Further, it is preferable that the cooling circuit module has a heat insulation structure between the second path and the first circulation path.

[0056] In the second mode, it is preferable that the power circuit module be cooled and the power transmission mechanism be warmed up. And since the cooling water flowing through the second path is supplied from the inlet, it is often at a lower temperature than the cooling water flowing through the first circulation path. It is preferable that the cooling water flowing through the first circulation path warm up quickly and that heat does not transfer from the first circulation path to the second path. By providing a heat insulation structure between the second path and the first circulation path, heat transfer from the first circulation path to the second path can be suppressed.

Explanation of Signs

[0057] 1: Cooling circuit module 3: Power circuit module 6: Air conditioner 10: Inlet 11: First connection part 12: Second connection part 13: Third connection part 14: Fourth connection part 20: Cooling water path 21: First path 22: Second path 23: Third path 25: First circulation path 26: Second circulation path 30: Outlet 31: First suction port 32: Second suction port 41: First discharge port 42: Second discharge port 51: First external flow path 53: Second external flow path 55: Radiator (third heat exchanger) 56: Chiller (fourth heat exchanger) 57: Battery cooler (fifth heat exchanger) 59: Heat insulation structure 71: Cooling unit (first heat exchanger) 72: Oil cooler (second heat exchanger) 100: Vehicle drive device BH: High-voltage battery (battery connected to the power circuit module) INV: Rotating Electric Machine Drive Circuit MG: Rotating Electric Machine TA: Power Transmission Mechanism V: Changeover Valve V1: First Valve V2: Second Valve V3: Third Valve W: Wheel WP: Water Pump (a pump for circulating cooling water)

Claims

1. A cooling circuit module mounted on a vehicle drive device including at least a rotating electrical machine serving as a driving force source for a wheel, a power transmission mechanism that transmits power between the wheel and the rotating electrical machine, and a power circuit module in which a power circuit including a rotating electrical machine drive circuit that drives the rotating electrical machine is formed, an inlet through which cooling water flows, an outlet through which the cooling water flows out, a first heat exchanger that exchanges heat between the power circuit module and the cooling water, and a cooling water passage to which a second heat exchanger that exchanges heat between oil that cools the rotating electrical machine and lubricates the power transmission mechanism and the cooling water is connected and through which the cooling water flows, a plurality of switching valves that switch the cooling water passage, wherein the cooling water passage is configured to be switchable to at least the first mode in which a first path from the inlet through the first heat exchanger and the second heat exchanger to the outlet is formed by changing states of the plurality of switching valves, a second mode in which a second path from the inlet through the first heat exchanger to the outlet and a first circulation path that circulates a closed circuit through the second heat exchanger are formed, and a third mode in which a third path directly connecting the inlet and the outlet and a second circulation path that circulates a closed circuit through the first heat exchanger and the second heat exchanger are formed, and is configured to be switchable to at least the first mode and at least one of the second mode and the third mode.

2. a first connection portion connected to a supply port of the cooling water to the first heat exchanger, a second connection portion connected to a discharge port of the cooling water from the first heat exchanger, a third connection portion connected to a supply port of the cooling water to the second heat exchanger, a fourth connection portion connected to a discharge port of the cooling water from the second heat exchanger, a pump that circulates the cooling water, the pump including a first suction port, a second suction port, a first discharge port that discharges the cooling water sucked from the first suction port, and a second discharge port that discharges the cooling water sucked from the second suction port, the plurality of switching valves including a first valve, a second valve, and a third valve, the pump having the first discharge port connected to the third connection portion, the second discharge port connected to the first valve, and the first suction port and the second suction port connected to the fourth connection portion via the third valve, the first valve being in a first state in which the inlet and the first connection portion are connected, ​ It is possible to switch to a second state in which the inlet and the outlet are connected and the first connection part and the second discharge port are connected. The second valve is switchable between a third state in which the second connection part and the third connection part are connected and a fourth state in which the second connection part and the outlet are connected. The third valve is switchable between a fifth state in which the fourth connection part and the outlet are connected a sixth state in which the fourth connection part and the first suction port are connected and a seventh state in which the fourth connection part and the second suction port are connected. In the first mode, the first valve is switched to the first state, the second valve is switched to the third state, and the third valve is switched to the fifth state. In the second mode, the first valve is switched to the first state, the second valve is switched to the fourth state, and the third valve is switched to the sixth state. In the third mode, the first valve is switched to the second state, the second valve is switched to the third state, and the third valve is switched to the seventh state. The cooling circuit module according to claim 1.

3. At least one of a third heat exchanger that performs heat exchange between the outside air and the cooling water on at least one side of a first external flow path through which the cooling water flowing into the inlet flows and a second external flow path through which the cooling water flowing out of the outlet flows, a fourth heat exchanger that performs heat exchange between the refrigerant of the air conditioner and the cooling water, and a fifth heat exchanger that performs heat exchange between a battery connected to the power circuit module and the cooling water is arranged. The cooling circuit module according to claim 1 or 2.

4. The cooling circuit module according to claim 1 or 2, comprising a heat insulation structure between the second path and the first circulation path.

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