JPH10238345A - Cooling device for hybrid electric automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent overheating of an engine after the stop of the engine as lowering of noise/vibration performance and power consumption of a battery are suppressed to a minimum limit. SOLUTION: When a key switch is turned off, cooling operation is respectively individually performed by a first cooling system 10 and a second cooling system until the water temperature of a second cooling system 15 is reduced to a value lower than a first given value. When the water temperature of the second cooling system is reduced to a value lower than the first given value, a second cooling system cooling water pump 18 is stopped, a cooling water passage is switched, and cooling water of the first cooling system is circulated amount a radiator 12, a second cooling system radiator 16, and a prime mover 2, and a second cooling system radiator and a cooling fan 19 are used for cooling of the first cooling system. Cooling capacity of the first cooling system to prevent the occurrence of the thermal damage of the engine, a generator 3, and an electric motor 7 after a key switch is turned OFF is improved, a first cooling system water temperature is reduced in a short time and noise/vibration performance due to operation noise and vibration of a pump and a fan is modified. Further, the operation times of the pump and the fan are shortened and power consumption of a battery is saved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device for a hybrid electric vehicle equipped with a prime mover, a generator, a motor and a battery as driving power sources, and more particularly to an improved method for cooling a prime mover and a motor.

[0002]

2. Description of the Related Art A hybrid electric vehicle equipped with a motor, a generator (hereinafter, referred to as a generator), an electric motor (hereinafter, referred to as a motor), and a battery (hereinafter, referred to as a battery) is known. In general, an internal combustion engine such as a gasoline engine or a diesel engine is used as a prime mover, and is simply referred to as an engine in this specification.

[0003] Hybrid electric vehicles include a parallel electric vehicle.
There are hybrid electric vehicles and series hybrid electric vehicles. A parallel hybrid electric vehicle uses an engine and a motor as a driving source for driving, and can drive not only by driving the engine and the motor at the same time, but also by driving one of the engine and the motor independently. Series hybrid electric vehicles use only a motor as a driving source, drive a generator by an engine, and charge a battery that supplies power to the motor with the power generated by the generator.

In this type of hybrid electric vehicle, a motor cooling system for cooling a motor and an engine cooling system for cooling an engine are separately provided.

FIG. 7 is a diagram showing a conventional cooling device for a hybrid electric vehicle. The engine cooling system circulates cooling water between the engine 101 and the radiator 102,
The cooling water superheated by the engine 101 is supplied to the radiator 10.
In step 2, cooling is performed by the cooling fan 103. On the other hand, the motor cooling system supplies cooling water to the power unit 104 and the motor 1.
05, circulate between the generator 106 and the radiator 107, and the cooling water superheated by the power unit 104, the motor 105 and the generator 106 is cooled by the cooling fan 108 by the radiator 107. In the conventional hybrid electric vehicle, the rotation directions of the cooling fans 103 and 108 of the engine cooling system and the motor cooling system are in the same direction as indicated by arrows.

Further, in order to prevent local overheating of the engine after the engine is stopped, there is provided an engine cooling device in which a cooling water pump and a cooling fan are driven even after the engine is stopped until the engine drops to a predetermined temperature. It is known (for example, see Japanese Patent Application Laid-Open No. 60-119318).

[0007]

Incidentally, in a hybrid electric vehicle, it is conceivable to cool the engine by the latter engine cooling device. However, since the cooling water pump and the cooling fan are driven even after the engine is stopped, their driving sounds and vibrations continue for a long time, and the sound and vibration performance deteriorates. Further, since the cooling water pump and the cooling fan are driven by the electric power of the battery after the engine is stopped, there is a problem that the charge amount of the battery is reduced.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a cooling device for a hybrid electric vehicle which prevents overheating of a prime mover after stopping the prime mover while minimizing deterioration of sound vibration performance and power consumption of a battery. It is in.

[0009]

[Means for Solving the Problems]

(1) According to the first aspect of the present invention, the cooling water is circulated between the prime mover and the first radiator by the first cooling water pump, and the first radiator cools the cooling water by the first cooling fan. A second cooling system in which cooling water is circulated by a second cooling water pump between a cooling system, a generator, an electric motor, and a second radiator, and the second radiator cools the cooling water by a second cooling fan. And a cooling system for a hybrid electric vehicle having the above cooling system. And the first
First temperature detecting means for detecting the temperature of the cooling water of the cooling system, second temperature detecting means for detecting the temperature of the cooling water of the second cooling system, and the first cooling system and the second Cooling water flow switching means for circulating cooling water separately with the cooling system, and circulating the cooling water of the first cooling system between the first radiator, the second radiator and the prime mover in the interlocking mode; Is turned off, the first cooling system and the second cooling system perform cooling operations independently until the cooling water temperature of the second cooling system falls below the first predetermined value. When the cooling water temperature of the cooling system 2 drops below the first predetermined value, the second cooling water pump is stopped,
Control means for switching to the interlock mode flow path by the cooling water flow path switching means. (2) In the cooling device for a hybrid electric vehicle according to the second aspect, after the control means switches to the cooling water flow path in the interlocking mode, if the cooling water temperature of the first cooling system falls below the second predetermined value, The first cooling water pump, the first cooling fan, and the second cooling fan are stopped. (3) The cooling device for a hybrid electric vehicle according to claim 3, wherein after the cooling operation of the second cooling system is stopped to a first predetermined value, a temperature that does not cause heat damage to the second cooling system is set;
After the cooling operation of the first cooling system is stopped, a temperature at which the first cooling system does not cause heat damage is set to a second predetermined value. (4) In the cooling device for a hybrid electric vehicle according to claim 4, the rotation directions of the first cooling fan and the second cooling fan are opposite to each other.

[0010]

【The invention's effect】

(1) According to the first aspect of the present invention, when the key switch is turned off, the first cooling system and the second cooling system are operated until the cooling water temperature of the second cooling system falls below the first predetermined value. When the cooling water temperature of the second cooling system falls below the first predetermined value, the second cooling water pump of the second cooling system is stopped and the cooling water flow path is switched. Circulating the cooling water of the first cooling system between the radiator of the first cooling system, the radiator of the second cooling system, and the prime mover, and connecting the radiator of the second cooling system and the cooling fan to the first cooling system. Is used to cool the cooling water of the engine, so that the heat damage to the prime mover, the generator and the motor after the key switch is turned off can be prevented, and the cooling capacity of the first cooling system increases, and the first cooling system can be cooled in a short time. The cooling water temperature of the cooling system can be lowered, It is possible to improve the sound and vibration performance due to the operation sound and vibration of the pump and the cooling fan. Further, since the operation time of the cooling water pump and the cooling fan after the key switch is turned off is shortened, the power consumption of the battery is saved. (2) According to the invention of claim 2, after switching to the cooling water flow path in the interlocking mode, when the cooling water temperature of the first cooling system falls below the second predetermined value, the cooling water pump of the first cooling system. The cooling fan and the cooling fan of the second cooling system are stopped to prevent heat damage to the prime mover after the key switch is turned off. In addition, the noise reduction is achieved by shortening the operation time of the cooling water pump and the cooling fan. Performance can be improved and battery power consumption can be reduced. (3) According to the invention of claim 3, the second predetermined value is set to the second predetermined value.
After the cooling operation of the cooling system is stopped, a temperature that does not cause heat damage to the second cooling system is set, and after the cooling operation of the first cooling system is stopped at the second predetermined value, the first cooling is performed. Since the temperature that does not cause heat damage to the system is set, it is possible to reliably prevent heat damage in the first cooling system and the second cooling system after the key switch is turned off. (4) According to the invention of claim 4, since the rotation directions of the first cooling fan and the second cooling fan are opposite to each other, the cooling air from the first cooling fan and the cooling air from the second cooling fan. The wind collides with and forms a wall between the two cooling winds. As a result, the cooling air superheated in the vicinity of the exhaust port of the prime mover flows into the second cooling system and the second cooling system having a low temperature
Thus, the cooling operation time in the single mode can be reduced without overheating the cooling system, and the sound vibration performance can be improved and the power consumption of the battery can be reduced.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a series hybrid electric vehicle will be described. FIG. 1 shows a configuration of a series hybrid electric vehicle according to an embodiment. The controller 1 includes a microcomputer and its peripheral components, and controls the engine 2, the generator 3, the converter 4, the inverter 6, and the motor 7. The engine 2 is a prime mover for driving the generator 3, and an internal combustion engine such as a gasoline engine or a diesel engine can be used. Generator 3 is a three-phase AC generator, and generates three-phase AC power. Converter 4 converts the three-phase AC power generated by generator 3 into DC power. Note that a DC generator can be used as the generator 3, and in that case, the converter 4 is not required.

The battery 5 charges the electric power generated by the engine 2 and the generator 3 through the converter 4 and discharges the electric power to the motor 7 through the inverter 6 as running power. As the battery 6, a lithium ion battery, a nickel hydrogen battery, a lead acid battery, or the like can be used. The inverter 6 converts DC power into AC power and applies it to the AC motor 7. The motor 7 drives the wheels 9 via a drive system 8. As the motor 7, an induction motor, a synchronous motor, a DC motor, or the like can be used. When a DC motor is used for the motor 7, a DC / DC converter is used instead of the inverter 6.

FIG. 2 is a diagram showing a configuration of a cooling device according to one embodiment. The engine cooling system 10 circulates cooling water between the engine 2 and the radiator 12 by the pump 11, and transfers the cooling water superheated by the engine 2 to the radiator 12.
And is cooled by the cooling fan 13. A flow switching valve 14 is provided on the cooling water outflow side of the radiator 12 of the engine cooling system 10 so that the cooling water is supplied to the engine cooling system 10.
It is switched between circulating only inside and circulating through the radiator 16 of the motor cooling system 15. Note that a water temperature sensor 17 is provided in the pipe of the engine cooling system 10 to detect the engine cooling water temperature Te.

The motor cooling system 15 circulates cooling water between the converter 4, the inverter 6, the motor 7, the generator 3 and the radiator 16 by the pump 18, and is superheated by the converter 4, the inverter 6, the motor 7 and the generator 3. The cooling water is cooled by a radiator 16 by a cooling fan 19. The motor cooling system 15 is provided with a flow path switching valve 20 on the cooling water inflow side of the radiator 16 and a flow path switching valve 21 on the cooling water outflow side of the radiator 16. It is switched whether to circulate the cooling water alone or to circulate the cooling water of the engine cooling system 10 to the radiator 16. A water temperature sensor 22 is provided in the pipe of the motor cooling system 15, and the motor cooling water temperature T
m is detected.

The cooling device of this embodiment has a single mode in which the engine cooling system 10 and the motor cooling system 15 perform cooling operations separately, and a radiator for the motor cooling system 15 after the cooling operation of the motor cooling system 15 is completed. 16
And an interlocking mode in which the cooling fan 19 is used for cooling the engine cooling system 10. In the single mode, as indicated by solid arrows, the flow path switching valves 14, 20, 21
Thus, separate cooling water circulation channels are formed in the engine cooling system 10 and the motor cooling system 15. In the engine cooling system 10, the cooling water is circulated between the engine 2 and the radiator 12 by the cooling water pump 11, and the cooling water superheated by the engine 2 is cooled by the cooling fan 13 by the radiator 12. Further, in the motor cooling system 15, cooling water is converted by the cooling water pump 18 into the converter 4,
Cooling water circulated between the inverter 6, the motor 7, the generator 3, and the radiator 16 and superheated by the converter 4, the inverter 6, the motor 7, and the generator 3 is cooled by the cooling fan 19 at the radiator 16.

In the interlocking mode, as indicated by the dashed arrow,
The cooling water flow path is switched by valves 14, 20, and 21, and the cooling water of engine cooling system 10 is supplied to engine 2, pump 11, radiator 12, valve 14, valve 2
0, a radiator 16, a valve 21, and a flow path circulating in the flow path of the engine 2 are formed. The radiator 16 of the motor cooling system 15 and the cooling fan 19 are used for cooling the cooling water of the engine cooling system 10. Further, the cooling water pump 18 of the motor cooling system 15 is stopped, and the flow of the cooling water in the flow path passing through the converter 4, the inverter 6, the motor 7, and the generator 3 is stopped. The cooling water of the engine cooling system 10 is circulated by the pump 11 in the flow paths of the radiator 12, the radiator 16, and the engine 2, and the cooling water superheated by the engine 2 is supplied to the fan 13 by the two radiators 12 and 16, respectively. Cooled by 19.

FIG. 3 is an electric circuit diagram of one embodiment.
1 and 2 are denoted by the same reference numerals, and description thereof is omitted. The controller 1 includes a drive control circuit 2a for the engine 2, a drive circuit 3a for the generator 3, a converter 4, an inverter 6, a key switch 23, a motor coolant temperature sensor 1
7. The engine coolant temperature sensor 22 is connected. In addition,
The key switch 23 is equivalent to an ignition key switch of a conventional vehicle equipped with an internal combustion engine. When the key switch 23 is set to the ON position, a main relay and an inverter relay (not shown) are turned on to enable the vehicle to travel. Become.

The controller 1 also includes a motor 11a for driving the cooling water pump 11 and a driver 11
b, a motor 18a for driving the cooling water pump 18
And a driver 18b, a motor 13a and a driver 13b for driving the cooling fan 13, a motor 19a and a driver 19b for driving the cooling fan 19, a solenoid 14a and a driver 14b for driving the flow path switching valve 14, and a flow path. A solenoid 20a and a driver 20b for driving the switching valve 20 and a solenoid 21a and a driver 21b for driving the flow path switching valve 21 are connected.

FIG. 4 is a diagram showing a change in cooling water temperature due to a cooling operation according to one embodiment. When the key switch 23 is turned on and the vehicle is operating, the cooling operation is performed in the above-described single mode in the engine cooling system 10 and the motor cooling system 15 respectively. When the key switch 23 is turned off at time t = 0, the engine cooling system 10
And the motor cooling system 15 continue to perform the cooling operation in the single mode, and the engine cooling water temperature and the motor cooling water temperature decrease along the characteristics Te and Tm indicated by solid lines, respectively.

When the cooling operation of the engine cooling system 10 is stopped immediately after the key switch 23 is turned off, the temperature of the engine cooling water rapidly rises once along the characteristic Te ", causing heat damage to the engine 2 and the like. Such a phenomenon is the same in the motor cooling system 15. Therefore,
In this embodiment, the cooling operation is continued in the single mode without stopping the cooling water pumps 11, 18 and the cooling fans 13, 19 immediately after the key switch 23 is turned off.

At time t1 after the motor cooling water temperature Tm has decreased to the predetermined value Tm1, the motor cooling water pump 1
8 is stopped, and the cooling operation of the motor cooling system 15 ends. Here, the predetermined value Tm1 is the value of the converter 4, inverter 6,
This is a temperature at which heat damage does not occur in the motor 7 and the generator 3. At this time, the flow path switching valve 14,
20 and 21 are switched to set the flow path in the interlocking mode described above. Thereby, the cooling water of the engine cooling system 10 is circulated through the motor cooling radiator 16 and is cooled by the fan 13 by the engine cooling radiator 12 and then further cooled by the motor cooling radiator 1.
At 6, it is cooled by the fan 19. As a result, the cooling capacity of the engine cooling water increases, and the engine cooling water temperature Te sharply decreases along the characteristic Te ′ indicated by the broken line. In the motor cooling system 15 in which the cooling operation has been stopped, at the time t1
Thereafter, the motor cooling water temperature Tm gradually decreases due to natural heat radiation.

At time t3 after the engine cooling water temperature Te has decreased to the predetermined value Te1, the engine cooling water pump 1
1. The cooling operation of the engine cooling system 10 is stopped by stopping the engine cooling fan 13 and the motor cooling fan 19. Here, the predetermined value Te1 is a temperature at which heat damage does not occur in the engine 2 even when the cooling operation of the engine cooling system 10 is stopped.

If the cooling operation is performed only in the single mode after the key switch is turned off, the engine cooling water temperature Te decreases along the characteristic shown by the solid line, and reaches the predetermined temperature Te1 after time t2. As described above, since the cooling capacity in the single mode of the engine cooling system 10 is lower than the cooling capacity in the interlock mode, the cooling operation time t2 only in the single mode is the time when cooling is performed by switching from the single mode to the interlock mode. Cooling operation time longer than 3. That is, in this embodiment in which the cooling operation is performed by switching from the single mode to the interlocking mode, the cooling operation time of the engine cooling system 10 can be reduced from the time t2 to the time t3.

When the cooling operation is performed only in the single mode after the key switch is turned off, the motor cooling water pump 18 and the motor cooling fan 19 are stopped after time t1.
After a time t2, the engine cooling water pump 11 and the engine cooling fan 13 are stopped. On the other hand, in this embodiment, the motor cooling water pump 18 is stopped after the time t1, and the motor cooling fan 19, the engine cooling water pump 11, and the engine cooling fan 13 are stopped after the time t3. Therefore, a comparison between the case where the cooling operation is performed only in the single mode after the key switch is turned off and the case where the cooling operation is performed by switching from the single mode to the interlocking mode after the key switch is turned off as in the present embodiment is compared with the embodiment. In this case, instead of extending the operation time of the motor cooling fan 19 by (t3−t1) time, the operation time of the engine cooling water pump 11 and the engine cooling fan 13 is reduced by (t2−t3) time.

The power consumption of the battery 5 for the extended operation time (t3-t1) of the motor cooling fan 19 is the same as that of the battery 5 for the reduced operation time (t2-t3) of the engine cooling water pump 11 and the engine cooling fan 13. Since the power consumption is smaller than the power consumption, in this embodiment, the power consumption of the battery 5 is reduced as compared with the cooling operation only in the single mode. Also, in this embodiment,
Since the engine cooling water pump 11 and the engine cooling fan 13 are stopped earlier than the cooling operation only in the single mode by (t2−t3) time, noise and vibration during operation of the cooling water pump and the fan are eliminated, and the sound vibration performance is reduced. improves.

FIG. 5 is a flowchart showing the cooling operation after the key switch is turned off. The operation of the embodiment will be described with reference to FIG. When the key switch 23 is turned off, the controller 1 executes the cooling operation shown in this flowchart. In step 1, measurement of the elapsed time after the key switch is turned off by the timer is started. In the following step 2, the engine cooling water temperature Te and the motor cooling water temperature Tm are detected by the water temperature sensors 17 and 22. Step 3
Then, the required operation time t4 after the key switch is turned off is predicted based on the detected engine coolant temperature Te.

In step 4, the motor cooling water temperature Tm is detected by the water temperature sensor 22, and it is confirmed whether the motor cooling water temperature Tm has fallen below the predetermined value Tm1.
If the motor cooling water temperature Tm falls below the predetermined value Tm1, the process proceeds to step 5, otherwise, the motor cooling water temperature Tm is detected again and compared with the predetermined value Tm1. When the motor cooling water temperature Tm falls below the predetermined value Tm1, the motor cooling water pump 18 is stopped in step 5, and the cooling operation of the motor cooling system 15 is stopped. Step 6
Then, the cooling water flow path is switched to the flow path in the interlock mode by the flow path switching valves 14, 20, 21. In step 7, it is checked whether the engine cooling water temperature Te has dropped below the predetermined value Te1, and if it has fallen below the predetermined value Te1, the routine proceeds to step 8, where the motor cooling fan 19, the engine cooling water pump 11 and the engine cooling fan 13 Is stopped, and the cooling operation of the engine cooling system 10 is stopped.

If it is determined in step 7 that the engine cooling water temperature Te has not fallen below the predetermined value Te1, the flow advances to step 9 to check whether or not the time measured by the timer has exceeded the predicted time. If the elapsed time from turning off the key switch exceeds the predicted cooling operation time, the process proceeds to step 10; otherwise, the process returns to step 7.
If the elapsed time after the key switch is turned off exceeds the predicted time, it is determined that there is an abnormality in the cooling device, and the occurrence of the abnormality is stored in a non-volatile memory (not shown) in step 10 and step 7
Return to Next, when the key switch 23 is turned on and the history of the occurrence of the abnormality is stored in the memory, the traveling of the vehicle is prohibited and a warning is issued.

As described above, when the key switch 23 is turned off, the cooling water temperature Tm of the motor cooling system 15 becomes the predetermined value Tm.
The cooling operation is independently performed by the engine cooling system 10 and the motor cooling system 15 until the cooling water temperature Tm drops below a predetermined value Tm1. Of the engine cooling system 1
0 is circulated between the engine cooling radiator 12, the motor cooling radiator 16 and the engine 2, and the radiator 16 of the motor cooling system 15 and the cooling fan 19 are cooled to cool the cooling water of the engine cooling system 10. Since it is used, it is possible to prevent heat damage to the engine 2, the generator 3, the converter 4, the inverter 6, and the motor 7 after the key switch is turned off, and the cooling capacity of the engine cooling system 15 is increased. The cooling water temperature of the cooling water pump and the cooling fan can be improved. In addition, since the operation time of the cooling water pump and the cooling fan after the key switch is turned off is shortened, the power consumption of the battery 5 is saved. After switching to the cooling water flow path in the interlocking mode, if the cooling water temperature Te of the engine cooling system 10 falls below the predetermined value Te1, the cooling water pump 11 and the cooling fan 13 of the engine cooling system 10 and the cooling of the motor cooling system 15 are performed. Since the fan 19 is stopped, heat damage to the engine 2 after the key switch is turned off can be prevented, and the sound vibration performance can be improved by shortening the operation time of the cooling water pump and the cooling fan, and the power consumption of the battery can be reduced. Can be reduced. Further, after the cooling operation of the motor cooling system 15 is stopped at the motor cooling water temperature predetermined value Tm1, a temperature that does not cause heat damage to the equipment of the motor cooling system 15 is set, and the engine cooling water temperature of the engine cooling system 10 is set at the predetermined engine cooling water temperature Te1. Since the temperature that does not cause heat damage to the engine 2 after the cooling operation is stopped, heat damage to the engine cooling system 10 and the motor cooling system 15 after the key switch is turned off can be reliably prevented.

Modification of Embodiment of the Invention In the above-described embodiment, an example in which the engine cooling fan 13 and the motor cooling fan 19 are rotated in the same direction has been described, but the rotation of the two cooling fans 13 and 19 is described. The directions may be opposite to each other. By setting the rotation directions of the engine cooling fan 13 and the motor cooling fan 19 in opposite directions, the cooling air from the engine cooling fan 13 and the cooling air from the motor cooling fan 19 collide, and a wall 25 is formed between the two cooling air. It is formed. As a result, engine 2
The cooling air superheated in the vicinity of the exhaust port (not shown) of the motor cooling system 15
Thus, the cooling operation time t1 in the single mode can be shortened without overheating the device, the sound vibration performance can be improved, and the power consumption of the battery can be reduced.

In the configuration of the above embodiment, the engine 2 serves as the prime mover, the engine cooling radiator 12 serves as the radiator of the first cooling system, the engine cooling water pump 11 serves as the first cooling water pump, and the engine cooling system. The system 10 is a first cooling system, the generator 3 is a generator, the motor 7 is an electric motor, and the motor cooling radiator 16 is a second cooling system.
Cooling system radiator, motor cooling water pump 18
Is the second cooling water pump, the motor cooling fan 19 is the second cooling fan, the engine cooling water temperature sensor 17 is the first temperature detecting means, and the motor cooling water temperature sensor 22 is the second cooling temperature detecting means. Water flow switching valve 14, 2
0 and 21 constitute the cooling water passage switching means, and the controller 1 constitutes the control means.

In each of the embodiments described above, a series hybrid electric vehicle has been described as an example. However, the present invention is not limited to a series hybrid electric vehicle, and may be applied to a parallel hybrid electric vehicle. it can.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a series hybrid electric vehicle according to an embodiment.

FIG. 2 is a diagram showing a configuration of a cooling device for a hybrid electric vehicle according to one embodiment.

FIG. 3 is an electric circuit diagram of one embodiment.

FIG. 4 is a diagram illustrating a change in cooling water temperature due to a cooling operation according to one embodiment.

FIG. 5 is a flowchart illustrating a cooling operation after a key switch is turned off according to the embodiment;

FIG. 6 is a diagram illustrating a configuration of a cooling device according to a modification of the embodiment.

FIG. 7 is a diagram showing a configuration of a conventional cooling device for a hybrid electric vehicle.

[Explanation of symbols]

 Reference Signs List 1 controller 2 engine 2a engine drive control circuit 3 generator 3a generator drive circuit 4 converter 5 battery 6 inverter 7 motor 8 drive system 9 wheels 10 engine cooling system 11 engine cooling water pump 11a motor 11b driver 12 engine cooling radiator 13 engine cooling fan 13a Motor 13b Driver 14, 20, 21 Cooling water flow path switching valve 14a, 20a, 21a Solenoid 14b, 20b, 21b Driver 15 Motor cooling system 16 Motor cooling radiator 17 Engine cooling water temperature sensor 18 Motor cooling water pump 18a Motor 18b driver 19 Motor cooling fan 19a Motor 19b Driver 22 Motor cooling water temperature sensor 23 Key switch 25 wall

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hiroyuki Hirano 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Prefecture Nissan Motor Co., Ltd. (72) Inventor Eiji Inada 2 Takaracho, Kanagawa-ku, Yokohama City, Kanagawa Nissan Motor Co. 72) Inventor Tsuyoshi Aso, 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Prefecture, Nissan Motor Co., Ltd. (72) Inventor Yutaro Kaneko, 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Prefecture, Nissan Motor Co., Ltd.

Claims (4)

[Claims] 1. A first cooling system in which cooling water is circulated between a prime mover and a first radiator by a first cooling water pump, and the first radiator cools cooling water by a first cooling fan. A second cooling water pump circulates cooling water between the generator, the electric motor, and the second radiator, and cools the cooling water with a second cooling fan by the second radiator.
A cooling system for a hybrid electric vehicle, comprising: a first temperature detecting means for detecting a cooling water temperature of the first cooling system; and a second temperature detecting means for detecting a cooling water temperature of the second cooling system. Temperature circulating means, and circulating cooling water separately in the first cooling system and the second cooling system in the single mode, and circulating the cooling water in the first cooling system in the interlocking mode. Cooling water flow path switching means for circulating between the radiator, the second radiator, and the prime mover; and, when a key switch of the vehicle is turned off, a cooling water temperature of the second cooling system becomes a first predetermined value. The first cooling system and the second cooling system perform the cooling operation independently until the cooling water temperature drops below the first cooling system, and the cooling water temperature of the second cooling system falls below the first predetermined value. When the cooling water pump 2 is stopped A cooling device for a hybrid electric vehicle, further comprising control means for switching to the interlocking mode flow path by the cooling water flow path switching means. 2. The cooling device for a hybrid electric vehicle according to claim 1, wherein the control unit switches a cooling water temperature of the first cooling system to a second predetermined value or less after switching to the flow path in the interlocking mode. The first cooling water pump, the first cooling fan, and the second cooling fan are stopped when the temperature of the cooling water is lowered to a lower value. 3. The cooling device for a hybrid electric vehicle according to claim 1, wherein the second cooling system is stopped after the cooling operation of the second cooling system is stopped at the first predetermined value. A temperature that does not cause heat damage to the first cooling system after the cooling operation of the first cooling system is stopped at the second predetermined value. A cooling device for a hybrid electric vehicle. 4. The cooling device for a hybrid electric vehicle according to claim 1, wherein rotation directions of the first cooling fan and the second cooling fan are opposite to each other. A cooling device for a hybrid electric vehicle.