阅读说明：本技术 电驱动车辆的冷却装置 (Cooling device for electrically driven vehicle ) 是由 清见原辰典 泉裕乡 长野直树 北冈宏隆 于 2020-08-13 设计创作，主要内容包括：一种电驱动车辆的冷却装置,抑制冷却液中的气泡所引起的冷却性能的降低。冷却装置(2)具备循环有冷却电动机(21)以及电气设备的冷却液的冷却液回路(第一冷却液回路(40))、连接于冷却液回路并且送出冷却液的泵(第一泵(27))、以及连接于冷却液回路并且使气泡从冷却液分离的脱气罐(第一脱气罐(23))。冷却液回路将电动机、电气设备、泵以及脱气罐以串联的方式连接。泵与电动机在冷却液回路中以依次排列的方式连接。冷却液从泵流向电动机。(A cooling device for an electrically driven vehicle, in which a decrease in cooling performance due to bubbles in a coolant is suppressed. The cooling device (2) is provided with a cooling liquid circuit (first cooling liquid circuit (40)) in which a cooling motor (21) and a cooling liquid for electrical equipment circulate, a pump (first pump (27)) which is connected to the cooling liquid circuit and which sends out the cooling liquid, and a degassing tank (first degassing tank (23)) which is connected to the cooling liquid circuit and which separates bubbles from the cooling liquid. The coolant circuit connects the motor, the electrical equipment, the pump, and the degassing tank in series. The pump and the motor are connected in a sequential arrangement in the coolant circuit. The coolant flows from the pump to the motor.)

1. A cooling device for an electrically driven vehicle, comprising:

an electric motor disposed in the engine room and configured to drive the vehicle;

an electrical device connected to an electrical circuit including the motor;

a cooling liquid circuit connected to the motor and the electrical equipment, and through which a cooling liquid for cooling the motor and the electrical equipment circulates;

a pump connected to the coolant circuit and sending out the coolant; and

a degassing tank connected to the cooling liquid circuit and separating gas bubbles from the cooling liquid,

the coolant circuit connecting the motor, the electrical equipment, the pump, and the degassing tank in series,

the pump and the motor are connected in a sequential arrangement in the coolant circuit,

the coolant flows from the pump to the motor.

2. The cooling apparatus of an electrically driven vehicle according to claim 1,

the cooling liquid circuit connects the degassing tank, the electrical equipment, the pump, the motor, and the degassing tank in this order,

the cooling liquid flows in the order of the degassing tank, the electrical equipment, the pump, the motor, and the degassing tank.

3. The cooling apparatus of an electrically driven vehicle according to claim 1 or 2,

a radiator for radiating the cooling liquid is provided,

the coolant circuit connects the motor, the radiator, and the degassing tank in this order,

the cooling liquid flows in the order of the motor, the radiator, and the degassing tank.

4. The cooling apparatus of an electrically driven vehicle according to claim 1 or 2,

the electric device includes a DC/DC converter for changing a voltage of a direct current and an inverter for outputting an alternating current to the motor,

the DC/DC converter and the inverter are connected in the coolant circuit in a sequential arrangement,

the coolant flows from the DC/DC converter to the inverter.

5. The cooling apparatus of an electrically driven vehicle according to claim 4,

the electrical device includes a charger for charging a battery,

the coolant circuit connects the DC/DC converter, the inverter, and the charger in series in this order,

the coolant flows in the order of the DC/DC converter, the inverter, and the charger.

6. The cooling apparatus of an electrically driven vehicle according to claim 5,

the DC/DC converter and the inverter are disposed in the nacelle,

the charger is arranged outside the engine room.

7. The cooling apparatus of an electrically driven vehicle according to claim 1 or 2,

comprises a generator and a converter for converting an AC current generated by the generator into a DC current,

the coolant circuit connects the electrical equipment, the converter, and the generator in this order,

the cooling liquid flows in the order of the electrical equipment, the converter, and the generator.

8. The cooling device of the electrically driven vehicle according to claim 1 or 2, wherein:

an engine mounted on the vehicle;

a second coolant circuit that is connected to the engine and in which a second coolant that cools the engine circulates;

a second pump connected to the second coolant circuit and sending out a second coolant; and

a second degassing tank connected to the second coolant circuit and separating gas bubbles from the second coolant,

the second coolant circuit connects the second degassing tank, the second pump, the engine, and the second degassing tank in series in this order,

the second coolant flows in the order of the second degassing tank, the second pump, the engine, and the second degassing tank.

9. The cooling apparatus of an electrically driven vehicle according to claim 8,

an oil cooler for cooling the lubricating oil of the engine,

the engine and the oil cooler are connected in the second coolant circuit in a sequential arrangement,

the second coolant flows in the order of the second degassing tank, the second pump, the engine, and the oil cooler.

10. The cooling apparatus of an electrically driven vehicle according to claim 1 or 2,

the pump and the degassing tank are disposed in the cabin.

11. The cooling apparatus of an electrically driven vehicle according to claim 2,

the degassing tank is arranged at the upper section in the vertical direction,

the pump and the motor are arranged at a lower section lower than the upper section,

the electric device is disposed above the pump and the motor and is located at the same position as or lower than the degassing tank.

12. The cooling apparatus of an electrically driven vehicle according to claim 11,

the electric device includes a DC/DC converter for changing a voltage of a direct current and an inverter for outputting an alternating current to the motor,

the DC/DC converter and the inverter are connected in the coolant circuit in a sequential arrangement,

the coolant flows from the DC/DC converter to the inverter,

the inverter is disposed below the DC/DC converter.

13. The cooling apparatus of an electrically driven vehicle according to claim 12,

the engine is provided with a generator coupled to the engine and a converter for converting an AC current generated by the generator into a DC current,

the coolant circuit connects the electrical equipment, the converter, and the generator in this order,

the cooling liquid flows in the order of the electric device, the converter, and the generator,

the engine and the generator are arranged on the lower section,

the DC/DC converter and the converter are arranged above the pump, the motor, the engine, and the generator and in a horizontal direction.

Technical Field

The technology disclosed herein relates to a cooling device of an electrically driven vehicle.

Background

Patent document 1 describes a cooling device for an electric vehicle. The cooling device cools the motor, the generator, and the electric equipment by the coolant.

The cooling device includes a coolant circuit, a pump, a radiator, and a storage tank. The coolant loop connects the motor, the generator, and the electrical equipment. The cooling fluid is pumped out. The radiator dissipates heat from the coolant. The storage tank stores the cooling liquid. The cooling fluid circulates in a cooling fluid circuit. The bubbles in the circulating coolant are sent to a storage tank. In the storage tank, the gas bubbles are separated from the coolant. The storage tank is a degassing tank.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2006-67735

Disclosure of Invention

Problems to be solved by the invention

The cooling liquid loop of the cooling device comprises a first loop connecting the pump, the electrical equipment, the motor, the generator, the radiator and the storage tank, and a second loop connecting the pump, the electrical equipment, the motor and the storage tank. The first loop is connected in parallel with the second loop.

If the coolant contains bubbles, the flow resistance of the coolant circuit is high. Since the first circuit is connected in parallel with the second circuit, if, for example, bubbles are present in the first circuit, the coolant is difficult to flow in the first circuit containing the bubbles and is easy to flow in the second circuit containing no bubbles. In the first circuit containing bubbles, the bubbles are difficult to be sent to the storage tank. Since the bubbles remain in the first circuit containing the bubbles, the cooling performance is degraded.

Further, if it is difficult for the air bubbles to be sent to the storage tank, there is a fear that the pump may suck the air bubbles. The efficiency of the pump that sucks the bubbles is reduced. In order to suppress a decrease in the efficiency of the pump, in the cooling device described in patent document 1, the pump is disposed immediately downstream of the storage tank. Since the reservoir tank separates the coolant from the bubbles, the coolant flowing from the reservoir tank to the pump does not contain bubbles. The suction of bubbles by the pump can be suppressed. However, the cooling device described in patent document 1 is limited in that the pump must be disposed immediately downstream of the storage tank.

The technology disclosed in the present application suppresses a reduction in cooling performance caused by air bubbles in a coolant in a cooling device of an electrically driven vehicle.

Means for solving the problems

The technology disclosed in the present application is a cooling device for an electrically driven vehicle.

The cooling device is provided with:

an electric motor disposed in the engine room and configured to drive the vehicle;

an electrical device connected to an electrical circuit including the motor;

a cooling liquid circuit connected to the motor and the electrical equipment, and through which a cooling liquid for cooling the motor and the electrical equipment circulates;

a pump connected to the coolant circuit and sending out the coolant; and

a degassing tank connected to the cooling liquid circuit and separating gas bubbles from the cooling liquid.

The coolant circuit connecting the motor, the electrical equipment, the pump, and the degassing tank in series,

the pump and the motor are connected in a sequential arrangement in the coolant circuit,

the coolant flows from the pump to the motor.

The coolant circuit connects the motor, the electrical equipment, the pump, and the degassing tank in series. When the pump is operated, the coolant is forcibly flowed in the coolant circuit. Even if the coolant contains bubbles, the bubbles are easily sent to the degassing tank. Since the degassing tank separates the coolant from the bubbles, it is difficult for the bubbles to remain in the coolant circuit. The cooling device can suppress the reduction of cooling performance caused by the bubbles.

The bubbles in the coolant circuit are mainly bubbles mixed during the production of the cooling device. Further, bubbles may be generated in the coolant during the running of the vehicle.

As described above, bubbles are less likely to remain in the coolant circuit. It is not necessary to arrange a pump at a position immediately downstream of the degassing tank in order to suppress the suction of bubbles. The cooling device has a high degree of freedom in the arrangement of the pump. The pump efficiency is not deteriorated wherever the pump is disposed on the coolant circuit. The pump stably sends out the cooling liquid. The cooling performance of the cooling device is high because the pump efficiency is high.

The cooling device of the above configuration connects the pump and the motor in a sequential arrangement. The pump can be disposed in the vicinity of the motor. The pump is disposed in the vicinity of the motor, which is a heavy object, so that the vibration acceleration input to the pump is reduced during the traveling of the vehicle. The reliability of the pump is improved.

The cooling liquid circuit may be configured to connect the degassing tank, the electrical equipment, the pump, the motor, and the degassing tank in this order,

the cooling liquid flows in the order of the degassing tank, the electrical equipment, the pump, the motor, and the degassing tank.

The electric device generates a lower amount of heat than the motor. The cooling liquid flows from the electrical equipment to the motor, so that the cooling device can efficiently cool each equipment. The cooling performance of the cooling device is improved.

Further, the coolant circuit can flow the coolant containing no bubbles from the degassing tank in the order of the electric device, the pump, and the motor. The cooling device efficiently cools the electric device and the motor. The reduction of the cooling performance of the cooling device is suppressed.

The cooling device may be provided with a radiator for radiating heat from the coolant,

the coolant circuit connects the motor, the radiator, and the degassing tank in this order,

the cooling liquid flows in the order of the motor, the radiator, and the degassing tank.

The coolant circuit connects the motor, the electrical equipment, the pump, the degassing tank, and the radiator in series. By connecting in series, it is difficult for the coolant circuit to contain bubbles. The reduction of the cooling performance of the cooling device is suppressed.

The motor generates a large amount of heat. The radiator is disposed at a position downstream of the motor. The radiator radiates heat from the coolant heated by the motor. The temperature of the cooling fluid decreases. The cooling performance of the cooling device is improved.

The electric device may include a DC/DC converter that changes a voltage of the direct current and an inverter that outputs an alternating current to the motor,

the DC/DC converter and the inverter are connected in the coolant circuit in a sequential arrangement,

the coolant flows from the DC/DC converter to the inverter.

The DC/DC converter generates a lower amount of heat than the inverter. The cooling liquid flows from the DC/DC converter to the inverter, so that the cooling device can efficiently cool each device. The cooling performance of the cooling device is improved.

It may also be provided that the electrical device comprises a charger for charging a battery,

the coolant circuit connects the DC/DC converter, the inverter, and the charger in series in this order,

the coolant flows in the order of the DC/DC converter, the inverter, and the charger.

The cooling liquid flows in the order of the DC/DC converter, the inverter, and the charger, so that the cooling device can efficiently cool each device.

It is also possible to provide that the DC/DC converter and the inverter are disposed in the nacelle,

the charger is arranged outside the engine room.

The charger is preferably disposed in the vicinity of the inlet of the charging plug. The charger is disposed at an appropriate position outside the nacelle. The DC/DC converter and the inverter are disposed in the nacelle, so that the motor, the DC/DC converter, and the inverter can be compactly disposed.

In addition, the nacelle may be provided at the front of the vehicle. In this case, the charger may be provided at the rear of the vehicle. The nacelle may also be provided at the rear of the vehicle. In this case, the charger may be provided at the front of the vehicle.

The cooling device may include a generator and a converter for converting an ac current generated by the generator into a dc current,

the coolant circuit connects the electrical equipment, the converter, and the generator in this order,

the cooling liquid flows in the order of the electrical equipment, the converter, and the generator.

The electric device generates a lower amount of heat than the converter. The converter generates less heat than the generator. The cooling liquid flows in the order of the electric device, the converter, and the motor, so that the cooling device can efficiently cool each device. The cooling performance of the cooling device is improved.

The cooling device may include:

an engine mounted on the vehicle;

a second coolant circuit that is connected to the engine and in which a second coolant that cools the engine circulates;

a second pump connected to the second coolant circuit and sending out a second coolant; and

a second degassing tank connected to the second coolant circuit and separating gas bubbles from the second coolant,

the second coolant circuit connects the second degassing tank, the second pump, the engine, and the second degassing tank in series in this order,

the second coolant flows in the order of the second degassing tank, the second pump, the engine, and the second degassing tank.

The engine may be an engine for driving a generator. The engine may be an engine for running the vehicle.

The allowable temperatures of the engine and the motor are different. Since the second coolant circuit is independent from the first coolant circuit, the second coolant circuit can appropriately cool the engine, and the first coolant circuit can appropriately cool the electric motor.

A second coolant loop connects the second degassing tank, the second pump, the engine, and the second degassing tank in series. Even if the second coolant contains bubbles, the bubbles are easily sent to the second degassing tank. Since the second degassing tank separates the cooling liquid from the bubbles, it is difficult for the second cooling liquid circuit to contain bubbles. The decrease in the cooling performance of the engine is suppressed.

Further, since the second coolant circuit hardly contains air bubbles, the degree of freedom in the arrangement of the second pump is high, as in the coolant circuit. No matter where the second pump is disposed on the second coolant circuit, the pump efficiency is not deteriorated. The cooling performance of the engine of the second coolant circuit is high because of the high pump efficiency.

An oil cooler for cooling the lubricating oil of the engine may be provided,

the engine and the oil cooler are connected in the second coolant circuit in a sequential arrangement,

the second coolant flows in the order of the second degassing tank, the second pump, the engine, and the oil cooler.

The temperature of the lubricating oil is also low when the engine is cold. The second coolant flows from the engine to the oil cooler, so that the oil cooler can heat the lubricating oil using the heat of the engine when the engine is cold. By raising the temperature of the lubricating oil in advance, the fuel consumption performance of the engine is improved.

The pump and the degassing tank may be disposed in the nacelle.

Since the motor, the pump, and the degassing tank are close to each other, the pipes of the coolant circuit are all long. Therefore, the flow resistance of the coolant circuit is low. The pump can be made small. In addition, the weight of the coolant circuit becomes light. Since the vehicle becomes light in weight, the range of the electrically driven vehicle is advantageously extended.

The degassing tank may be disposed at an upper stage in the vertical direction,

the pump and the motor are arranged at a lower section lower than the upper section,

the electric device is disposed above the pump and the motor and is located at the same position as or lower than the degassing tank.

By providing the degassing tank at the upper stage, bubbles in the coolant tend to concentrate toward the degassing tank. It is difficult for bubbles to remain in the coolant circuit.

The cooling liquid flows from the degassing tank in the order of the electric equipment, the pump, and the motor. The cooling liquid flows from the degassing tank disposed in the upper stage to the pump and the motor disposed in the lower stage via the electrical equipment. That is, the coolant flows sequentially from top to bottom. The pipe of the coolant circuit is not provided with or is not easily provided with a bent portion in the vertical direction. The retention of air bubbles in the bent portion can be suppressed. The cooling performance of the cooling device is not easily reduced.

The pump is disposed in the lower stage together with the motor. During the running of the vehicle, the vibration acceleration input to the pump is reduced. The reliability of the pump is improved.

The electric device may include a DC/DC converter that changes a voltage of the direct current and an inverter that outputs an alternating current to the motor,

the DC/DC converter and the inverter are connected in the coolant circuit in a sequential arrangement,

the coolant flows from the DC/DC converter to the inverter,

the inverter is disposed below the DC/DC converter.

The coolant flows from the upper DC/DC converter to the lower inverter. The pipe of the coolant circuit is not provided with or is not easily provided with a bent portion in the vertical direction. The retention of air bubbles in the bent portion can be suppressed.

The cooling device may include a generator coupled to the engine and a converter for converting an ac current generated by the generator into a dc current,

the coolant circuit connects the electrical equipment, the converter, and the generator in this order,

the cooling liquid flows in the order of the electric device, the converter, and the generator,

the engine and the generator are arranged on the lower section,

the DC/DC converter and the converter are arranged above the pump, the motor, the engine, and the generator and in a horizontal direction.

The coolant flows from the upper converter to the lower generator. The pipe of the coolant circuit is not provided with or is not easily provided with a bent portion in the vertical direction. The retention of air bubbles in the bent portion can be suppressed.

The pump, the motor, the engine, and the generator are disposed in the lower stage, and the DC/DC converter and the converter are disposed horizontally above the device. Since the respective devices are disposed at positions close to each other, the entire length of the coolant circuit is short. The pump is advantageously downsized and the coolant circuit is advantageously light-weighted.

Effects of the invention

As described above, according to the cooling device for an electrically driven vehicle described above, it is possible to suppress a decrease in cooling performance due to air bubbles in the coolant.

Drawings

Fig. 1 is a block diagram illustrating a configuration of a cooling device of an electrically driven vehicle.

Fig. 2 is a block diagram illustrating a configuration of an electric circuit of the electrically driven vehicle.

Fig. 3 is a plan view showing the power unit and the cooling device disposed in the nacelle.

Fig. 4 is a front view of the power unit and the cooling device disposed in the nacelle as viewed from the front.

Fig. 5 is a rear view of the power unit and the cooling device disposed in the nacelle as viewed from the rear.

Fig. 6 is a side view showing the power unit and the cooling device disposed in the cabin, and the charger disposed in the rear of the vehicle.

Description of the reference numerals

1 vehicle

10 power unit

11 nacelle

2 Cooling device

20 electric circuit

21 electric motor

22 first radiator

23 first degassing tank

24 DC/DC converter (electric equipment)

25 inverter (electric equipment)

26 charger (electric equipment)

27 first pump

28 cell

30 second cooling liquid circuit

31 engine

32 oil cooler

34 second degassing tank

36 second pump

37 converter

38 electric generator

40 first cooling liquid circuit

Detailed Description

Hereinafter, an embodiment of a cooling device for an electrically driven vehicle will be described with reference to the drawings. The cooling device described here is an example.

(construction of Power Unit and Cooling device)

Fig. 1 is a block diagram illustrating a configuration of a cooling device 2 of an electrically driven vehicle. Fig. 2 is a block diagram illustrating the configuration of power unit 10 and electric circuit 20 of the electrically driven vehicle. The Vehicle 1 is a so-called EV (Electric Vehicle). The power unit 10 has a motor 21, an inverter 25, and a battery 28. The range increasing unit 3 described later is included in the power unit 10. The electric circuit 20 includes a motor 21, an inverter 25, and a battery 28.

The electric motor 21 is a motor for driving the vehicle 1. The motor 21 is connected to the left and right drive wheels 15 via a reduction gear 17 and an axle 16.

The inverter 25 is connected to the motor 21. The inverter 25 supplies an alternating current to the motor 21. The motor 21 operates by receiving an ac current from the inverter 25. The inverter 25 is an example of an electrical device.

The inverter 25 is also connected to a battery 28. The inverter 25 converts a direct current from the battery 28 into an alternating current.

A charger 26 is connected to the battery 28. Charger 26 has insertion port 261. A charging plug 262 is inserted into the insertion port 261. The charger 26 receives a current from an external power supply of the vehicle 1, and charges the battery 28. The charger 26 is an example of an electrical device.

The battery 28 is also connected to a DC/DC converter 24. The DC/DC converter 24 changes the voltage of the direct current from the battery 28. The DC/DC converter 24 supplies the DC current after voltage reduction to various electric components 29 mounted on the vehicle 1. The DC/DC converter 24 is an example of an electrical device.

The vehicle 1 is a so-called range Extender EV (Range Extender EV). The vehicle 1 is equipped with a generator 38 and an engine 31. The engine 31 is combined with a generator 38. The engine 31 is an engine for generating electric power. The generator 38 receives the power of the engine 31 to generate electric power.

A converter 37 is connected to the generator 38. The converter 37 converts the alternating current generated by the generator 38 into direct current. The converter 37 is connected to the battery 28. The converter 37 charges the battery 28 with the current generated by the generator 38.

The engine 31, the generator 38, and the converter 37 constitute an integrated range extending unit 3. The vehicle 1 not equipped with the range-extending unit 3 is a so-called BEV (Battery EV).

As shown in fig. 1, the cooling device 2 cools the motor 21, the electrical equipment, the converter 37, and the generator 38. The electric apparatus includes the above-described DC/DC converter 24, inverter 25, and charger 26. Although not shown, the motor 21, the DC/DC converter 24, the inverter 25, the charger 26, the converter 37, and the generator 38 each have an inlet for the coolant, an outlet for the coolant, and a passage through which the coolant flows.

The cooling device 2 has a first cooling liquid circuit 40. The motor 21, the DC/DC converter 24, the inverter 25, the charger 26, the converter 37, and the generator 38 are connected to a first coolant circuit 40. The first coolant loop 40 is a closed loop. The first cooling fluid circulates within the first cooling fluid circuit 40.

The cooling apparatus 2 further has a first pump 27, a first radiator 22, and a first degassing tank 23. The first pump 27 sends out the first coolant. The first radiator 22 radiates heat from the first coolant. The first degassing tank 23 separates bubbles from the first coolant. The bubbles in the first cooling liquid are mainly bubbles mixed in during the production of the cooling device 2. Further, during the running of the vehicle 1, bubbles may be generated in the coolant.

The first pump 27 is an electric pump. The first pump 27 is interposed between the generator 38 and the motor 21 in the first coolant circuit 40. The first pipe 41 connects the outlet 27b of the first pump 27 and the inlet 21a of the cooling liquid of the motor 21. The ninth pipe 49 connects the outlet 38b of the coolant of the generator 38 to the inlet 27a of the first pump 27 (see also fig. 4).

The first radiator 22 and the first deaeration tank 23 are interposed between the motor 21 and the DC/DC converter 24 in the first coolant circuit 40. The second pipe 42 connects the outlet 21b of the coolant of the motor 21 to the inlet 22a of the first radiator 22. The third pipe 43 connects the outlet 22b of the first radiator 22 and the inlet 23a of the first deaeration tank 23. The fourth pipe 44 connects the outlet 23b of the first degassing tank 23 to the inlet 24a of the coolant of the DC/DC converter 24 (see also fig. 4 and 6).

The fifth pipe 45 connects the outlet 24b of the coolant of the DC/DC converter 24 and the inlet 25a of the coolant of the inverter 25. Sixth pipe 46 connects outlet 25b of the coolant of inverter 25 and inlet 26a of the coolant of charger 26. Seventh pipe 47 connects outlet 26b of the coolant of charger 26 to inlet 37a of the coolant of converter 37. The eighth pipe 48 connects the outlet 37b of the coolant of the converter 37 and the inlet 38a of the coolant of the generator 38 (see also fig. 4, 5, and 6).

A first coolant loop 40 connects the devices in series. The first coolant flows from the first degassing tank 23 in the order of the DC/DC converter 24, the inverter 25, the charger 26, the converter 37, the generator 38, the first pump 27, the motor 21, the first radiator 22, and the first degassing tank 23.

Here, the charger 26 is disposed at the rear of the vehicle 1. Insertion port 261 is provided on a side surface of the rear portion of vehicle 1. Charger 26 is preferably disposed near insertion port 261. By disposing charger 26 outside cabin 11, inlet 261 of charging plug 262 can be provided at an appropriate position of vehicle 1. By disposing each device other than the charger 26 in the nacelle 11, the power unit 10 is downsized.

The cooling device 2 also cools the engine 31. As shown in fig. 1, the cooling device 2 has a second coolant circuit 30 that is independent of the first coolant circuit 40. The second coolant circuit 30 is connected to an engine 31 and an oil cooler 32. The allowable temperatures of the engine 31 and the electric motor 21 are different. The first coolant circuit 40 is independent from the second coolant circuit 30, so that the first coolant circuit 40 can appropriately cool the electric motor 21 and other devices, and the second coolant circuit 30 can appropriately cool the engine 31.

The second pump 36, the second radiator 33, the second degassing tank 34, and the temperature control valve 35 are connected to the second coolant circuit 30. The second pump 36 sends out the second coolant. The engine 31 drives the second pump 36. The second radiator 33 radiates heat from the second coolant. The second degassing tank 34 separates the gas bubbles from the second cooling liquid. The thermo valve 35 is an on-off valve that opens and closes according to the temperature of the second coolant. The temperature control valve 35 opens when the second coolant is at a low temperature so that the second coolant bypasses the second radiator 33. When the temperature of the second coolant is high, the thermo valve 35 is closed to allow the second coolant to pass through the second radiator 33.

A second coolant loop 30 connects the devices in series. The second coolant flows from the second degassing tank 34 in the order of the thermo valve 35, the second pump 36, the engine 31, the oil cooler 32, the second radiator 33, and the second degassing tank 34. Further, the engine 31, the oil cooler 32, the second radiator 33, the second deaeration tank 34, the thermo valve 35, and the second pump 36 are disposed in the nacelle 11. These devices are compactly configured with each other. The piping of the second coolant circuit 30 is all short. Therefore, the flow resistance of the coolant circuit is low. The second pump 36 can be made small. In addition, the second coolant circuit 30 becomes lightweight. Since the vehicle becomes light in weight, the range of the electrically driven vehicle is advantageously extended.

The range extending unit 3 includes an engine 31, an oil cooler 32, a second radiator 33, a second degassing tank 34, a thermo valve 35, a second pump 36, a converter 37, and a generator 38, as surrounded by a dotted line in fig. 1.

Although the illustration of the BEV not equipped with the range-extending unit 3 is omitted, the cooling device is different from the cooling device 2 of fig. 1 in configuration. Specifically, the first coolant circuit 40 connects the outlet 26b of the coolant of the charger 26 and the inlet 27a of the first pump 27.

(layout of Power Unit and Cooling device)

Next, the layout of the power unit 10 and the cooling device 2 configured as described above will be described with reference to fig. 3 to 6. Fig. 3 is a plan view showing the power unit 10 and the cooling device 2 arranged in the nacelle 11. Fig. 4 is a front view of the power unit 10 and the cooling device 2 disposed in the nacelle 11 as viewed from the front. Fig. 5 is a rear view of the power unit 10 and the cooling device 2 disposed in the nacelle 11 as viewed from the rear. Fig. 6 is a side view showing the power unit 10 and the cooling device 2 disposed in the cabin 11, and the charger 26 disposed in the rear of the vehicle. In fig. 3 to 6, only the first coolant circuit 40 is shown in the cooling device 2, and the second coolant circuit 30 is not shown. The arrows in fig. 4 to 6 indicate the flow direction of the coolant.

In the following description, the longitudinal direction of the vehicle 1 is referred to as the front-rear direction, the front of the vehicle 1 is referred to as the "front", and the rear of the vehicle 1 is referred to as the "rear". A direction orthogonal to the vehicle length direction of the vehicle 1 is referred to as a vehicle width direction. The right direction with respect to an occupant seated in a passenger compartment 18 (see fig. 3) of the vehicle 1 is referred to as "right", and the left direction with respect to the occupant is referred to as "left".

As described above, the power unit 10 is disposed in the nacelle 11. The nacelle 11 is provided in front of the cabin 18. A side frame 12 is disposed in the nacelle 11. The two side frames 12 are arranged with a space therebetween in the vehicle width direction, i.e., in the left-right direction on the paper of fig. 3. Each side frame 12 extends in the front-rear direction of the vehicle 1, i.e., in the vertical direction of the paper of fig. 3.

As shown in fig. 3, the power unit 10 includes an electric motor 21, a speed reducer 17, and a range-extending unit 3. As described above, the range extending unit 3 includes the engine 31 and the generator 38. The motor 21 is disposed on the right side in the nacelle 11, and the range extending unit 3 is disposed on the left side in the nacelle 11. As shown in fig. 4 and 5, the electric motor 21, the reduction gear 17, the engine 31, and the generator 38 are arranged in the vehicle width direction. The motor 21, the reducer 17, the engine 31, and the generator 38 are integrated. The power unit 10 is relatively long in the vehicle width direction.

The power unit 10 is disposed between the side frames 12 and 12. The right end of the power unit 10 is supported by the right side frame 12 via a mount 13. The left end of the power unit 10 is supported by the left side frame 12 via a mount 14. As shown in fig. 4 and 5, the power unit 10 is suspended by the mounts 13 and 14 fixed to the side frames 12.

A first radiator 22 is disposed in front of the power unit 10. The first radiator 22 is located at a front end portion of the nacelle 11.

As shown in fig. 4 and 5, the first degassing tank 23 is disposed at an upper stage in the nacelle 11. In other words, the height position at which the first degassing tank 23 is provided is referred to as an "upper stage".

The third pipe 43 is connected to the front part of the lower part of the first degassing tank 23. Further, a fourth pipe 44 is connected to a side portion of the lower portion of the first degassing tank. The inlet 23a of the first degassing tank 23 has the same height as, or approximately the same height as, the outlet 23 b. The inlet 23a and the outlet 23b of the first degassing tank 23 are located in the upper section.

A DC/DC converter 24 is provided after the first degassing tank 23. As shown in fig. 6, the first degassing tank 23 is interposed between the first radiator 22 and the DC/DC converter 24 in the front-rear direction.

As shown enlarged in fig. 6, the first degassing tank 23 is fixed to the DC/DC converter 24 by a bracket 231 and a bolt 232. A part of the first degassing tank 23 is opposed to the DC/DC converter 24 in the front-rear direction.

The DC/DC converter 24 has a box shape extending in the vertical direction and the vehicle width direction. The DC/DC converter 24 is provided at a height spanning from the upper stage to the middle stage. The middle section means a position lower than the upper section and higher than the lower section described later. That is, the DC/DC converter 24 is disposed at the same position as the first degassing tank 23 or at a position lower than the first degassing tank 23.

The fourth pipe 44 is connected to the upper left portion of the front portion of the DC/DC converter 24. The height of the inlet 24a of the DC/DC converter 24 is the same as, or substantially the same as, the height of the outlet 23b of the first degassing tank 23. The fourth pipe 44 extends in the horizontal direction. A fifth pipe 45 is connected to a lower left portion of the front portion of the DC/DC converter 24. The outlet 24b of the DC/DC converter 24 has a lower height than the inlet 24 a.

The inverter 25 is disposed in the middle stage. More specifically, the inverter 25 is disposed above the motor 21 and the reduction gear 17 and below the DC/DC converter 24. The inverter 25 has a box shape extending in the vehicle width direction and the front-rear direction.

The fifth pipe 45 is connected to the upper left portion of the front portion of the inverter 25. The height of the inlet 25a of the inverter 25 is lower than the height of the outlet 24b of the DC/DC converter 24. The fifth pipe 45 extends obliquely downward. The sixth pipe 46 is connected to the left side portion of the inverter 25. The height of the inlet 25a and the height of the outlet 25b of the inverter 25 are the same or substantially the same. The inlet 25a and the outlet 25b of the inverter 25 are located in the middle.

As shown in fig. 6, the charger 26 is disposed at the rear of the vehicle 1. The charger 26 is disposed in the middle section. The sixth piping 46 extends from the cabin 11 to the rear of the vehicle 1 through the underfloor of the vehicle 1. The sixth pipe 46 once descends downward from the front toward the rear, and thereafter ascends upward again to reach the charger 26. Charger 26 has a box shape that extends in the vehicle width direction and the front-rear direction. Sixth pipe 46 is connected to a side portion of charger 26.

Seventh pipe 47 is connected to a side portion of charger 26. The inlet 26a of the charger 26 has the same height as or substantially the same height as the outlet 26 b. The inlet 26a and the outlet 26b of the charger 26 are located in the middle.

The seventh pipe 47 also extends from the rear of the vehicle to the cabin 11 at the front of the vehicle 1 through the underfloor of the vehicle 1, as in the sixth pipe 46. The seventh pipe 47 descends once from the rear of the vehicle 1 toward the front, and then ascends again upward to reach the nacelle 11.

The converter 37 is disposed at a position spanning from the upper stage to the middle stage. The converter 37 is located above the engine 31. The converter 37 and the DC/DC converter 24 are arranged in the horizontal direction, more specifically, the vehicle width direction. The converter 37 has a box shape extending in the vertical direction. As shown in fig. 5, a seventh pipe 47 is connected to a lower portion of the rear portion of the converter 37.

The eighth pipe 48 is connected to a middle portion of the rear portion of the converter 37. The outlet 37b of the cooling liquid of the converter 37 is higher than the inlet 37 a. The inlet 37a and the outlet 37b of the coolant of the converter 37 are located in the middle. The eighth pipe 48 extends from the rear side to the front side of the power unit 10.

The generator 38 is located at the left end of the power unit 10. The engine 31 is disposed adjacent to the right side of the generator 38. The generator 38 and the engine 31 are disposed from the middle stage to the lower stage. The eighth piping 48 is connected to the middle of the front portion of the generator 38. The height of the inlet 38a of the coolant of the generator 38 is lower than the height of the outlet 37b of the converter 37.

The ninth piping 49 is connected to the middle of the front portion of the generator 38. The outlet 38b of the coolant of the generator 38 is lower in height than the inlet 38 a.

The first pump 27 is disposed in the lower stage. The first pump 27 is located before the motor 21 and the reducer 17. The ninth pipe 49 is connected to the upper portion of the first pump 27. The inlet 27a of the first pump 27 is higher than the outlet 38b of the generator 38. The inlet 27a of the first pump 27 has the same height as or substantially the same height as the outlet 27 b. The inlet 27a and the outlet 27b of the first pump 27 are located at the lower stage.

The electric motor 21 is disposed at the right end of the power unit 10. The motor 21 is disposed in the lower stage. In other words, the height position at which the motor 21 is disposed is referred to as "lower stage". The motor 21 and the reduction gear 17 are arranged in the horizontal direction, i.e., in the vehicle width direction. As described above, the inverter 25 is disposed above the motor 21 and the reduction gear 17.

The first pipe 41 connects the outlet 27b of the first pump 27 and the inlet 21a of the cooling liquid of the motor 21. The inlet 21a is located at the upper left side of the front of the motor 21. The height of the inlet 21a of the cooling liquid of the motor 21 is higher than the height of the outlet 27b of the first pump 27. The outlet 21b of the cooling liquid of the motor 21 is located at the upper right side of the front of the motor 21. The height of the outlet 21b is the same as or substantially the same as the height of the inlet 21 a. The inlet 21a and the outlet 21b are located at the lower stage.

The second pipe 42 is connected to the outlet 21 b. As shown in fig. 6, the second pipe 42 extends forward. The second pipe 42 is connected to the coolant inlet 22a of the first radiator 22. The inlet 22a is provided at a side portion of the first heat sink 22. The inlet 22a is lower than the outlet 21b of the cooling liquid of the motor 21. The inlet 22a is located in the lower section.

The third pipe 43 is connected to the outlet 22b of the first radiator 22. The outlet 22b is provided at the upper end of the first heat sink 22. The third pipe 43 extends obliquely upward rearward. As described above, the third pipe 43 is connected to the inlet 23a of the first degassing tank 23. The inlet 23a has a height higher than that of the outlet 22b of the first heat sink 22.

As shown in fig. 1, the first coolant circuit 40 connects the motor 21, the first radiator 22, the first degassing tank 23, the DC/DC converter 24, the inverter 25, the charger 26, the converter 37, the generator 38, and the first pump 27 in series. When the first pump 27 is operated, the first coolant forcibly flows in the first coolant circuit 40. Even if the first coolant contains bubbles, the bubbles are easily sent to the first degassing tank 23. Since the first degassing tank 23 separates the first coolant from the bubbles, it is difficult for the bubbles to remain in the first coolant circuit 40. The cooling device 2 can suppress a reduction in cooling performance due to air bubbles in cooling the motor 21 and the electric equipment.

Since the first coolant circuit 40 of the series structure hardly retains bubbles, it is not necessary to dispose the first pump 27 immediately downstream of the first degassing tank 23 in order to suppress the suction of bubbles. The degree of freedom in the arrangement of the first pump 27 of the cooling device 2 is high. No matter where the first pump 27 is disposed on the first coolant circuit 40, the pump efficiency is not deteriorated. The first pump 27 can stably send out the first coolant. The cooling performance of the cooling device 2 is high because the pump efficiency is high.

In addition, in the BEV without the range-extending unit 3, bubbles are less likely to remain in the first coolant circuit 40, as described above. The cooling device 2 can suppress a reduction in cooling performance due to air bubbles in cooling the motor 21 and the electric equipment. Further, since the first pump 27 is less likely to suck air bubbles and has high pump efficiency, the cooling performance of the cooling device 2 is high.

The second coolant circuit 30 also connects the engine 31, the oil cooler 32, the second radiator 33, the second deaeration tank 34, the thermo valve 35, and the second pump 36 in series. Even if the second coolant contains bubbles, the bubbles are easily sent to the second degassing tank 34. Since the second degassing tank 34 separates the second coolant from the bubbles, it is difficult for the bubbles to remain in the second coolant circuit 30. The cooling device 2 can suppress the reduction of the cooling performance due to the air bubbles even in the cooling of the engine 31.

Further, since bubbles are less likely to remain in the second coolant circuit 30, the degree of freedom in the arrangement of the second pump 36 is high. No matter where the second pump 36 is disposed on the second coolant circuit 30, the pump efficiency is not deteriorated. The cooling performance of the engine 31 of the second coolant circuit 30 is high because of the high pump efficiency.

The first coolant, which dissipates heat in the first radiator 22 and has separated bubbles in the first degassing tank 23, flows in the order of the DC/DC converter 24, the inverter 25, the charger 26, the converter 37, the generator 38, and the motor 21. The DC/DC converter 24 generates a lower amount of heat than the inverter 25, the inverter 25 generates a lower amount of heat than the converter 37, the converter 37 generates a lower amount of heat than the generator 38, and the generator 38 generates a lower amount of heat than the motor 21. Since the first cooling liquid passes through the respective devices in order of low heat generation amount, the cooling device 2 can efficiently cool the respective devices.

Further, since the first cooling liquid passing through each apparatus does not contain bubbles, a decrease in cooling performance of the cooling device 2 is suppressed.

The first radiator 22 is located immediately downstream of the motor 21, which generates a large amount of heat, in the first coolant circuit 40. The first radiator 22 radiates heat from the first coolant after the heat is received from the motor 21, so that the temperature of the first coolant is effectively lowered. The cooling performance of the cooling device 2 is improved.

In the second coolant circuit 30, the temperature of the lubricating oil is also low when the engine 31 is cold. In the second coolant circuit 30, the second coolant flows from the engine 31 to the oil cooler 32. Thus, the oil cooler 32 can heat the lubricating oil by the heat of the engine 31 when the engine 31 is cold. The fuel consumption performance of the engine 31 is improved.

In the first coolant circuit 40, the first degassing tank 23 is disposed at the upper stage, and therefore bubbles in the first coolant tend to concentrate toward the first degassing tank 23. Thus, the first coolant circuit 40 is less likely to contain bubbles.

Further, the DC/DC converter 24 is disposed at a position extending from the upper stage to the middle stage, the inverter 25 and the charger 26 are disposed at the middle stage, and the inlet 37a and the outlet 37b of the coolant of the converter 37 are disposed at the middle stage. The inlet 38a and the outlet 38b of the generator 38 are disposed at the lower stage, and the first pump 27 and the motor 21 are disposed at the lower stage. Thereby, the first cooling liquid flows from top to bottom in sequence. The pipes 41 to 49 constituting the first coolant circuit 40 are not provided with or hardly provided with vertically bent portions. The retention of air bubbles in the bent portion can be suppressed. The cooling performance of the cooling device 2 is not easily lowered.

The first degassing tank 23, the DC/DC converter 24, the inverter 25, the motor 21, the first pump 27, the converter 37, the engine 31, and the generator 38 are arranged in the vertical direction. Further, the DC/DC converter 24 and the converter 37 are arranged horizontally above the power unit 10. The configuration of these devices is compact. Further, since the devices are close to each other, the overall length of the pipes 41 to 49 of the first coolant circuit 40 is short. Therefore, the flow resistance of the first coolant circuit 40 is low. If the flow resistance of the first coolant circuit 40 is low, the first pump 27 can be downsized. In addition, the first coolant circuit 40 becomes light in weight. Since the vehicle becomes light in weight, the extension of the cruising distance of the vehicle 1 is facilitated.

Further, the first pump 27 is disposed in the lower stage together with the motor 21, the engine 31, and the generator 38, which are heavy objects, so that the vibration acceleration input to the first pump 27 is reduced during the traveling of the vehicle 1. The reliability of the first pump 27 is improved.

As shown in fig. 6, the first degassing tank 23 is interposed between the DC/DC converter 24 and the first radiator 22 in the front-rear direction. The first degassing tank 23 can alleviate the collision load input to the DC/DC converter 24 at the time of a vehicle collision.

In addition, the nacelle may be provided at the rear of the vehicle 1. The charger 26 may also be provided at the front of the vehicle.