JP2005188333A - Cooling device for hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To properly control the temperature states of a plurality of apparatuses, different in temperature, as device constitution is prevented from being complicated. <P>SOLUTION: In case a temperature T_DV or a temperature T_PDU of a process development unit (PDU) is increased to temperature higher than a given temperature #T (or in case the temperature T_PDU is increased to temperature higher than the given temperature #T), first of all a cooling fan is operated to cool a radiator. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a cooling device for a hybrid vehicle driven by an internal combustion engine and a motor.

Conventionally, for example, with respect to a radiator provided in a cooling circuit that circulates cooling water for cooling an engine, a part of the cooling water that circulates in the radiator is diverted and circulated again in the radiator. In addition to the main flow path, an additional flow path is provided, and the cooling water flowing through this additional flow path, that is, the flow path in the radiator is relatively longer than the cooling water flowing through the main flow path. An apparatus that controls the temperature of hydraulic oil such as ATF (Automatic Transmission Fluid), for example, with cooling water having a low temperature is known (for example, see Patent Document 1).
US Pat. No. 6,196,168

By the way, conventionally, in a hybrid vehicle including a motor that is a driving source of a vehicle together with an internal combustion engine, in addition to cooling the internal combustion engine, cooling of a high-voltage electric device including a motor and an inverter that supplies electric power to the motor is performed. Necessary.
However, the internal combustion engine and the high-voltage electrical equipment may have different management temperatures. For example, even when the cooling water having a plurality of different temperatures is discharged by the radiator according to the related art as described above, When an independent cooling circuit system is provided for each of the plurality of cooling waters, there arises a problem that the device configuration becomes complicated and the mounting property on the vehicle is impaired.
In addition, if the circulation of the cooling water in the cooling circuit is stopped when the operation of the internal combustion engine is stopped, or if the circulation flow rate of the cooling water is relatively decreased during the idling operation of the internal combustion engine, There exists a possibility that the temperature of an apparatus may rise exceeding predetermined management temperature.
The present invention has been made in view of the above circumstances, and provides a cooling device for a hybrid vehicle capable of appropriately controlling the temperature states of a plurality of devices having different management temperatures while preventing the device configuration from becoming complicated. The purpose is to do.

  In order to solve the above-described problems and achieve the object, the hybrid vehicle cooling device according to the first aspect of the present invention includes an internal combustion engine and a motor as power sources, and can travel by at least the driving force of the motor. The internal combustion engine mounted on a hybrid vehicle and a power control means (for example, PDU 14 and downverter 15 in the embodiment described later) for controlling the power supply to the on-vehicle electric device including the motor are shared. A cooling device for a hybrid vehicle that cools with cooling water, wherein the power control means is arranged in an engine room in which the internal combustion engine is accommodated, and a diversion flow in which a part of the cooling water for cooling the internal combustion engine is diverted A radiator that is cooled by cooling water, and that cools the cooling water and the divided cooling water; Radiator cooling fan (for example, cooling fan 29, cooling fans 29a and 29b in the embodiment described later) and temperature detecting means for detecting the temperature of the power control means (for example, an embodiment described later) Step S01, step S11, step S21) and an operation control means for operating the radiator cooling fan when the temperature detected by the temperature detection means is equal to or higher than a predetermined temperature (for example, an embodiment described later) Step S02, Step S13, Step S14, Step S24, Step S25).

  According to the cooling device for a hybrid vehicle having the above-described configuration, for example, even when the internal combustion engine is stopped or when the internal combustion engine is idling, the motor control means for controlling the operating state of the motor and the transfer of electric energy to and from the motor. It is possible to suppress an excessive increase in the temperature of the power control means including a transformer means for stepping down and outputting the voltage between the terminals of the power storage device to be performed or the output voltage of the motor. That is, by operating the radiator cooling fan when the temperature of the power control means becomes equal to or higher than a predetermined temperature, for example, the engine consumes relatively less power than when driving a circulation pump or the like for circulating cooling water. Ventilation in the room and heat radiation from the radiator can be promoted, and the temperature of the cooling water can be prevented from rising excessively. As a result, for example, a special device such as a circulation pump that can prevent an increase in cost required for improving the heat resistance of the power control means or circulate cooling water regardless of the operating state of the internal combustion engine, for example. It is possible to prevent an increase in the cost required for providing the.

  Furthermore, a cooling device for a hybrid vehicle according to a second aspect of the present invention includes an internal combustion engine and a motor as power sources, and is mounted on a hybrid vehicle that can travel at least by the driving force of the motor. A hybrid vehicle cooling device that cools power control means (for example, a PDU 14 and a downverter 15 in an embodiment described later) with a common cooling water to control power supply to an in-vehicle electric device including the motor. The power control means is cooled by a diverted cooling water in which a part of the cooling water for cooling the internal combustion engine is diverted, and is driven in synchronization with the rotation of the crankshaft of the internal combustion engine. A water pump (for example, a water pump 21 in an embodiment to be described later) that circulates in the flow path, and detects the temperature of the power control means Temperature detection means (for example, step S31, step S33, step S36 in the embodiment described later), and when the temperature detected by the temperature detection means when the internal combustion engine is stopped is equal to or higher than a predetermined temperature, Crankshaft rotation driving means for rotating the crankshaft (for example, step S37 in the embodiment described later) is provided.

  According to the cooling device for a hybrid vehicle having the above configuration, even when the operation of the internal combustion engine is stopped, the motor control means for controlling the operating state of the motor or the voltage across the terminals of the power storage device for exchanging electric energy with the motor or the motor It is possible to suppress an excessive increase in the temperature of the power control means including the transformer means for stepping down and outputting the output voltage. That is, when the temperature of the power control means becomes equal to or higher than a predetermined temperature, for example, the water pump is driven by rotating the crankshaft by the driving force of the motor while the cylinder of the internal combustion engine is stopped, and the cooling water is supplied. The power control means can be cooled by circulating in the flow passage. This prevents, for example, an increase in the cost required to improve the heat resistance of the power control means, or improves the fuel efficiency compared to driving the water pump by starting the internal combustion engine and rotating the crankshaft, for example. Can be made.

According to the cooling device for a hybrid vehicle of the first aspect of the present invention, for example, a circulation pump that circulates cooling water or the like by operating the radiator cooling fan when the temperature of the power control means becomes equal to or higher than a predetermined temperature. The power consumption is relatively small compared to the case of driving the engine, ventilation in the engine room and heat radiation from the radiator can be promoted, and the temperature of the cooling water can be prevented from rising excessively. As a result, for example, a special device such as a circulation pump that can prevent an increase in cost required for improving the heat resistance of the power control means or circulate cooling water regardless of the operating state of the internal combustion engine, for example. It is possible to prevent an increase in the cost required for providing the.
Further, according to the cooling device for a hybrid vehicle of the present invention as set forth in claim 2, when the temperature of the power control means becomes equal to or higher than a predetermined temperature, for example, the driving force of the motor in a state where the cylinder of the internal combustion engine is deactivated. For example, when the crankshaft is rotated in order to prevent an increase in the cost required for improving the heat resistance of the power control means, for example, or when the water pump is driven by starting the internal combustion engine and rotating the crankshaft The power control means can be cooled while improving fuel efficiency.

Hereinafter, a first embodiment of a cooling device for a hybrid vehicle of the present invention will be described with reference to the accompanying drawings.
The hybrid vehicle cooling device 10 according to the first embodiment includes a hybrid vehicle 1 having a structure in which an internal combustion engine 11, a motor 12, and a transmission (T / M) 13 are directly connected in series as shown in FIG. In this hybrid vehicle 1, for example, the driving forces of both the internal combustion engine 11 and the traveling motor 12 are applied to the driving wheels W via a transmission (T / M) 13 such as a CVT or a manual transmission. Communicated.
The motor 12 generates an auxiliary driving force that assists the driving force of the internal combustion engine 11 in accordance with the operating state of the hybrid vehicle 1. Further, when the driving force is transmitted from the wheel W side to the motor 12 side during deceleration of the hybrid vehicle 1, the motor 12 functions as a generator to generate a so-called regenerative braking force, and recovers the kinetic energy of the vehicle body as electric energy. To do.

Regenerative operation and driving of the motor 12 are performed by a PDU (power drive unit) 14 in response to a control command from a motor control device (not shown). For example, the PDU 14 includes an inverter formed by bridge-connecting switching elements composed of a plurality of transistors, and is connected to a power storage device (not shown) including a high-voltage battery and the like that exchange electric energy with the motor 12. ing.
Further, in this high-voltage power storage device, a 12-volt auxiliary battery (not shown) for driving various auxiliary machines of the hybrid vehicle 1 is provided with a downverter (D / V) 15 comprising a DC-DC converter. The downverter 15 steps down the voltage of the power storage device and charges the auxiliary battery.
In the hybrid vehicle 1, the PDU 14 and the downverter 15 are disposed in the vicinity of the transmission 13 in an engine room in which the internal combustion engine 11 is accommodated, for example.

  The hybrid vehicle cooling device 10 according to the first embodiment includes a water pump (W / P) 21 driven by an internal combustion engine 11 or a motor 12, a radiator 22, and a first thermostat 23, as shown in FIG. And a second thermostat 24, a water jacket 25 inside the internal combustion engine 11, a heater core 26, first and second temperature sensors 27 and 28, and a cooling fan 29.

In this cooling device 10 for a hybrid vehicle, for example, a water jacket 25 is disposed on the downstream side of the water pump 21, and the coolant that has circulated through the water jacket 25 and has a relatively high temperature is two first and second cooling waters. It distribute | circulates to the flow paths 30a and 30b.
A heater core 26 is connected to the first flow path 30a via an appropriate valve 26a. The heater core 26 heats air using a relatively high-temperature cooling water as a heat source, and the heat exchanged by the heater core 26 is performed. Water returns to the water pump 21 through the third flow path 30c.

The first flow path 30a bypasses the valve 26a and the heater core 26 and is connected to the third flow path 30c. The fourth flow path 30d supplies cooling water to the throttle body 31 and the breather 32 that forms the ventilation device. Is provided.
And the 2nd flow path 30b is formed in the 5th flow path 30e for distribute | circulating a cooling water to the radiator 22, and an internal diameter smaller than this 5th flow path 30e, for example, and is connected to the 3rd flow path 30c. It branches to the sixth flow path 30f.
The second flow path 30b is provided with a first temperature sensor 27 that detects the temperature of the cooling water discharged from the water jacket 25.

  The radiator 22 includes, for example, an inlet side tank 22A connected to the fifth flow path 30e, and an outlet side tank 22B connected to the seventh flow path 30g connected to the third flow path 30c via the first thermostat 23. The main flow path 22a inside the radiator connecting the inlet side tank 22A and the outlet side tank 22B, and the sub flow path 22b inside the radiator connected to the outlet side tank 22B are configured. Further, for example, an eighth flow path 30h that supplies cooling water to the heat sink portions 14a and 15a of the PDU 14 and the downverter 15 that are arranged to face each other and the cooling flow path 12a of the motor 12 is connected to the sub flow path 22b. The eighth flow path 30h is connected to the third flow path 30c via the second thermostat 24.

That is, the interior of the radiator 22 is partitioned into a main flow path 22a and a sub flow path 22b by a partition plate or the like, and the main flow path 22a and the sub flow path 22b are configured to communicate with each other in the outlet side tank 22B.
And the cooling water introduced into the inlet side tank 22A of the radiator 22 from the 5th flow path 30e first distribute | circulates the main flow path 22a inside the radiator 22, and appropriate 1st temperature (for example, about 80 degreeC etc.). Until cooled.
Next, at least a part of the cooling water flowing through the main flow path 22a and introduced into the outlet side tank 22B flows through the sub flow path 22b inside the radiator 22, and the flow path inside the radiator 22 is relatively By being long, it is possible to cool to an appropriate second temperature (for example, about 60 ° C. or the like) lower than the first temperature.
A second temperature sensor 28 that detects the temperature of the cooling water discharged from the cooling flow path 12a of the motor 12 is provided at a position downstream of the motor 12 in the eighth flow path 30h. When the detection result output from the sensor 28 exceeds a predetermined temperature, the cooling fan 29 that cools the radiator 22 is set to operate under the control of a control device (not shown).

  The first and second thermostats 23 and 24 are set to change from the closed state to the open state when the temperature of the cooling water is in a high temperature state exceeding each predetermined temperature, and mainly the temperature of the internal combustion engine 11. Compared to a predetermined first set temperature (for example, about 82 ° C.) at which the first thermostat 23 that performs adjustment is in an open state, a second thermostat 24 that mainly performs temperature adjustment of the high-pressure system is in a predetermined state at which the adjustment is performed. The second set temperature (for example, about 65 ° C.) is set to a lower temperature.

  The hybrid vehicle cooling device 10 according to the first embodiment has the above-described configuration. Next, the operation of the hybrid vehicle cooling device 10 will be described.

In this cooling device 10 for a hybrid vehicle, when the temperature of the cooling water is relatively low, such as when the internal combustion engine 11 is started, the first thermostat 23 and the second thermostat 24 are closed, for example, FIG. The cooling water discharged from the water jacket 25 returns to the water pump 21 so as to bypass the radiator 22 as shown in a distribution path Fa (for example, broken line arrow Fa in FIG. 2).
That is, the cooling water discharged from the water jacket 25 sequentially flows through the first flow path 30a, the heater core 26 or the fourth flow path 30d, and the third flow path 30c, or the second flow path 30b and the sixth flow path. It flows through the flow path 30f and the third flow path 30c and returns to the water pump 21.

When the temperature of the cooling water becomes higher than a predetermined second set temperature (for example, about 65 ° C.), the second thermostat 24 is opened. For example, the flow path Fb shown in FIG. 2 (for example, the solid arrow in FIG. 2) As in Fb), the cooling water discharged from the water jacket 25 further circulates to the radiator 22 and is cooled in two steps in the course of flowing through the main flow path 22a and the sub flow path 22b of the radiator 22. Are supplied to the PDU 14, the downverter 15, and the motor 12.
That is, the cooling water discharged from the water jacket 25 is, in order, the first flow path 30a, the fifth flow path 30e, the main flow path 22a, the sub flow path 22b, the eighth flow path 30h, the second thermostat 24, It flows through the third flow path 30 c and returns to the water pump 21.

  When the temperature of the cooling water becomes higher than a predetermined first set temperature (for example, about 82 ° C.), the first thermostat 23 is opened, and the cooling water flowing through the main flow path 22a of the radiator 22 The third flow passage 30c is circulated from the seventh flow passage 30g through the first thermostat 23, and then returned to the water pump 21.

The operation of a control device (not shown) for controlling the operating state of the cooling fan (RADFAN) 29 that cools the radiator 22 will be described below.
First, for example, in step S01 shown in FIG. 3, it is determined whether or not the temperature T_DV of the downverter 15 or the temperature T_PDU of the PDU 14 is higher than a predetermined temperature #T (for example, # T = 80 ° C. or the like).
The temperature T_DV of the downverter 15 and the temperature T_PDU of the PDU 14 may be estimated based on the detection result of the second temperature sensor 28 that detects the temperature of the cooling water discharged from the cooling flow path 12a of the motor 12, for example. Further, it may be a detection result of a temperature sensor (not shown) that detects the temperatures T_DV and T_PDU.
When the determination result is “NO”, the series of processes is terminated.
On the other hand, when the determination result is “YES”, the operation of the cooling fan 29 is started, and the series of processes is ended.

For example, the circulation of the cooling water in each flow path is stopped with the operation stop of the internal combustion engine 11 at the time of idle stop or the water pump 21 of the water pump 21 with the low load operation of the internal combustion engine 11 at the time of idle operation. When the output decreases relatively and the circulation amount of the cooling water decreases, the temperature of the cooling water in the water jacket 25 of the internal combustion engine 11 in the relatively high temperature state rises, and the cooling water flows into the cooling water flow passage. Convection (that is, heat transfer) due to the temperature difference occurs. And even if the water pump 21 is stopped due to the operation stop of the internal combustion engine 11 by this convection, relatively high-temperature cooling water flows from the internal combustion engine 11 side to the vicinity of the PDU 14 and the downverter 15. The temperature of the PDU 14 and the downverter 15 rises.
Here, as shown in steps S01 to S02 described above, when the temperature T_DV of the downverter 15 or the temperature T_PDU of the PDU 14 becomes higher than the predetermined temperature #T (or higher than the predetermined temperature #T). First, by operating the cooling fan 29, ventilation in the engine room and heat radiation from the radiator 22 are promoted, and the temperature of the cooling water in the flow passage is prevented from rising excessively. It is possible to prevent the PDU 14 and the downverter 15 from exceeding a predetermined management temperature and becoming overheated.

According to the hybrid vehicle cooling device 10 of the first embodiment, when the temperature T_DV of the downverter 15 or the temperature T_PDU of the PDU 14 is higher than the predetermined temperature #T (or higher than the predetermined temperature #T). First, by operating the cooling fan 29, for example, the operation of the water pump 21 in a stopped state is started or the output of the water pump 21 is increased. Therefore, it is possible to suppress the temperature of the cooling water in the flow path from rising excessively, and to prevent the PDU 14 and the downverter 15 from exceeding a predetermined management temperature and becoming overheated. This prevents, for example, an increase in the cost required to improve the heat resistance of the PDU 14 and the downverter 15, and prevents, for example, a relatively high-temperature cooling water from flowing toward the vicinity of the PDU 14 and the downverter 15. It is possible to prevent the cost required for providing the switching valve and the like from increasing.
In addition, the main flow path 22a and the sub flow path 22b communicating with the main flow path 22a are provided inside the single radiator 22, and the temperature of the cooling water can be lowered in two stages, so that the device configuration and cooling can be reduced. A plurality of systems having different management temperatures, for example, an internal combustion engine 11 and a high-pressure system (for example, PDU 14) that is set at a relatively low temperature compared to the internal combustion engine 11 while suppressing the complexity of the water flow path. In addition, it is possible to perform appropriate temperature management with the common cooling water for the downverter 15 and the motor 12 and the like.
In addition, by combining the cooling water discharged from a plurality of systems having different management temperatures on the upstream side of the single water pump 21, the temperature state of each system deviates from a desired state while simplifying the device configuration. Can be easily suppressed.
In addition, since the first thermostat 23 and the second thermostat 24 are provided and the cooling water is set to circulate around the radiator 22 and the high-pressure system, for example, during the warm-up operation of the internal combustion engine 11, It is possible to improve the temperature rise characteristic when raising the temperature of the system to a desired temperature.

In the first embodiment described above, the cooling fan 29 is simply operated when the temperature T_DV of the downverter 15 or the temperature T_PDU of the PDU 14 becomes higher than the predetermined temperature #T. However, the present invention is not limited to this. For example, the downverter is operated as in the operation of a control device (not shown) for controlling the operation state of the cooling fan (RADFAN) 29 according to the first modification of the first embodiment shown in FIG. Depending on the temperature T_DV of 15 or the temperature T_PDU of the PDU 14, the operating characteristics of the cooling fan 29 in operation may be changed.
For example, in step S11 shown in FIG. 4, it is determined whether the temperature T_DV of the downverter 15 or the temperature T_PDU of the PDU 14 is higher than a predetermined first temperature # T1 (for example, # T1 = 80 ° C.).
The predetermined first temperature # T1 is a value having hysteresis.
If this determination is “NO”, the flow proceeds to step S 12, the cooling fan 29 in operation is stopped, and a series of processing is ended.
On the other hand, if the determination is “YES”, the flow proceeds to step S13.

In step S13, whether the temperature T_DV of the downverter 15 or the temperature T_PDU of the PDU 14 is higher than a predetermined second temperature # T2 (for example, # T2 = 90 ° C. or the like) higher than the predetermined first temperature # T1. Determine whether.
The predetermined second temperature # T2 is a value having hysteresis.
If this determination is “YES”, the flow proceeds to step S 14, the cooling fan 29 is operated with the predetermined first characteristic (characteristic 1), and the series of processes is ended.
On the other hand, if this determination is “NO”, the flow proceeds to step S 15, the cooling fan 29 is operated with the predetermined second characteristic (characteristic 2), and the series of processes is ended.
The predetermined first characteristic and second characteristic with respect to the operating state of the cooling fan 29 are, for example, as shown in FIG. 5, the rotational speed of the cooling fan 29 according to an increase in the rotational speed (engine rotational speed) of the internal combustion engine 11. (RADFAN rotation speed) is set as a predetermined change. For example, in the first characteristic, the RADFAN rotation speed is set to rapidly increase as the engine rotation speed increases in a region where the engine rotation speed is relatively small. In the region where the number is relatively large, the RADFAN rotational speed is set to increase constantly or gradually as the engine rotational speed increases. On the other hand, in the second characteristic, the region where the engine speed is set to be gradually increased as the engine speed is increased in a region where the engine speed is relatively small, and the engine speed is relatively large. In this case, the RADFAN rotational speed is set to rapidly increase as the engine rotational speed increases.
That is, in the first characteristic, the cooling water in the flow passage can be forcibly rapidly cooled, and in the second characteristic, the operation of the cooling fan 29 is compared to the noise generated by the operation of the internal combustion engine 11. Accordingly, it is possible to cool the cooling water in the flow passage while preventing excessive noise from being generated.

In the first embodiment described above, the single cooling fan 29 that cools the radiator 22 is provided. However, the present invention is not limited to this. For example, the second modification of the first embodiment shown in FIG. As in the hybrid vehicle cooling apparatus 10 according to the first embodiment, a plurality of, for example, a first cooling fan (first RADFAN) 29a that cools the main flow path 22a inside the radiator and a second cooling fan that cools the sub flow path 22b inside the radiator ( 2nd RADFAN) 29b, for example, as shown in FIG. 7, the operating states of the cooling fans 29a and 29b may be changed according to the temperature T_DV of the downverter 15 or the temperature T_PDU of the PDU 14.
For example, in step S21 shown in FIG. 7, it is determined whether the temperature T_DV of the downverter 15 or the temperature T_PDU of the PDU 14 is higher than a predetermined first temperature # T1 (for example, # T1 = 80 ° C.).
The predetermined first temperature # T1 is a value having hysteresis.
If this determination is “NO”, the flow proceeds to step S22, the operating cooling fans 29a and 29b are stopped, and a series of processing is ended.
On the other hand, if this determination is “YES”, the flow proceeds to step S23.

In step S23, whether the temperature T_DV of the downverter 15 or the temperature T_PDU of the PDU 14 is higher than a predetermined second temperature # T2 (for example, # T2 = 90 ° C. or the like) higher than the predetermined first temperature # T1. Determine whether.
The predetermined second temperature # T2 is a value having hysteresis.
If this determination is “YES”, the flow proceeds to step S 24, the first and second cooling fans 29 a and 29 b are operated, and the series of processes is ended.
On the other hand, if this determination is “NO”, the flow proceeds to step S 25, only the second cooling fan 29 b is operated, and the series of processing is ended.
Thereby, a desired cooling performance can be ensured while preventing excessive energy consumption.

A second embodiment of the hybrid vehicle cooling device of the present invention will be described below with reference to the accompanying drawings.
The hybrid vehicle cooling device 10 according to the second embodiment has a configuration equivalent to that of the hybrid vehicle cooling device 10 according to the first embodiment described above. Hereinafter, the second embodiment will be described. The operation of the cooling device 10 for the hybrid vehicle will be described.
In the hybrid vehicle cooling device 10, for example, in the operation stop state of the internal combustion engine 11 such as when idling is stopped, the operation of the cooling fan 29 that cools the radiator 22 according to the temperature T_DV of the downverter 15 or the temperature T_PDU of the PDU 14 and The operation of the water pump 21 for circulating the cooling water is controlled.
For example, in step S31 shown in FIG. 8, it is determined whether the temperature T_DV of the downverter 15 or the temperature T_PDU of the PDU 14 is higher than a predetermined first temperature #Ta (for example, # Ta = 80 ° C. or the like). .
The predetermined first temperature #Ta is a value having hysteresis.
When the determination result is “NO”, the series of processes is terminated.
On the other hand, if this determination is “YES”, the flow proceeds to step S32, the cooling fan 29 is operated, and the flow proceeds to step S33.

In step S33, the temperature T_DV of the downverter 15 or the temperature T_PDU of the PDU 14 is higher than a predetermined second temperature #Tb (for example, # Tb = 85 ° C. or the like) higher than the predetermined first temperature #Ta. It is determined whether or not it is too high.
The predetermined second temperature #Tb is a value having hysteresis.
When the determination result is “NO”, the series of processes is terminated.
On the other hand, if this determination is “YES”, the flow proceeds to step S34.
In step S34, it is determined whether or not the remaining capacity SOC of the power storage device is higher than a predetermined lower limit remaining capacity #S (for example, # S = 40% or the like).
If the determination result in step S34 is “NO”, it is determined that it is not preferable to drive the motor 12 by supplying power from the power storage device, the process proceeds to step S35, the internal combustion engine 11 in a stopped state is started, The water pump 21 is operated by the driving force of the internal combustion engine 11 to circulate the cooling water.
On the other hand, if the determination result of step S34 is “YES”, the process proceeds to step S36.
In step S36, the temperature T_DV of the downverter 15 or the temperature T_PDU of the PDU 14 is higher than a predetermined third temperature #Tc (for example, # Tc = 90 ° C. or the like) higher than the predetermined second temperature #Tb. It is determined whether or not it is too high.
The predetermined third temperature #Tc is a value having hysteresis.
If the determination result in step S36 is "YES", it is determined that the water pump 21 needs to be operated with a relatively large output, and the process proceeds to step S35 described above.
On the other hand, when the determination result of step S36 is “NO”, the process proceeds to step S37, where the motor 12 is driven by the power supply from the power storage device, the water pump 21 is operated by the driving force of the motor 12, and the cooling water is supplied. Circulate and end the series of processing.
In this step S37, when the internal combustion engine 11 is an internal combustion engine that can be operated with at least some cylinders being deactivated, the engine friction is reduced by deactivating the cylinders, and the water pump 21 is efficiently operated. Can be operated.
The predetermined lower limit remaining capacity #S in step S34 is a value having hysteresis (for example, 40% on the high side and 30% on the low side). That is, when the remaining capacity SOC exceeds the high side (for example, 40%) of the lower limit remaining capacity #S, motor idling is permitted, while the remaining capacity SOC is low for the lower limit remaining capacity #S (for example, 30%). %), The internal combustion engine 11 is started.

  According to the hybrid vehicle cooling device 10 according to the second embodiment, for example, when the circulation of the cooling water in the flow passage is stopped in the operation stop state of the internal combustion engine 11 such as at the time of idling stop, Even if the temperature of the downverter 15 rises due to the operation of the downverter 15 being continued as power is supplied from the power storage device to the 12V auxiliary machinery, excessive energy consumption occurs in the hybrid vehicle. It is possible to prevent the temperature of the cooling water in the flow passage from rising excessively while preventing the PDU 14 and the downverter 15 from exceeding a predetermined management temperature and becoming overheated. This prevents, for example, an increase in the cost required to improve the heat resistance of the PDU 14 and the downverter 15, and prevents, for example, a relatively high-temperature cooling water from flowing toward the vicinity of the PDU 14 and the downverter 15. It is possible to prevent the cost required for providing the switching valve and the like from increasing.

A third embodiment of the hybrid vehicle cooling device of the present invention will be described below with reference to the accompanying drawings.
The hybrid vehicle cooling device 10 according to the third embodiment has a configuration equivalent to that of the hybrid vehicle cooling device 10 according to the first embodiment described above. Hereinafter, the third embodiment will be described. The operation of the cooling device 10 for the hybrid vehicle will be described.

First, for example, in step S41 shown in FIG. 9, it is determined whether or not the vehicle speed (vehicle speed) V is zero.
When the determination result is “NO”, that is, when the vehicle is traveling, a series of processing is terminated.
On the other hand, when the determination result is “YES”, that is, when the vehicle is stopped, the process proceeds to Step S42.
In step S42, it is determined whether or not the temperature T_DV of the downverter 15 or the temperature T_PDU of the PDU 14 is higher than a predetermined temperature #THNE (for example, # THNE = 70 ° C. or the like).
When the determination result is “NO”, the series of processes is terminated.
On the other hand, if this determination is “YES”, the flow proceeds to step S43, the engine speed is limited to a predetermined upper limit speed (eg, 3000 rpm) or less, and the series of processes is terminated.

  For example, when charging the power storage device when the vehicle is stopped, the motor 12 is driven as a generator by the driving force of the internal combustion engine 11 with the shift position set to neutral, and the generated energy generated by the power generation of the motor 12 is used. The power storage device may be charged. In this case, for example, after time t0 shown in FIG. 10, in addition to the increase in the remaining capacity SOC of the power storage device, the engine 22 circulates in the radiator 22 as the engine speed (NE) of the internal combustion engine 11 increases. The flow rate of the cooling water increases excessively, the time during which the cooling water stays in the radiator 22 becomes excessively short, and the temperature of the PDU 14 and the downverter 15 (T_DV, T_PDU) increases due to the increase in the temperature of the cooling water. . Here, when the temperature T_DV of the downverter 15 or the temperature T_PDU of the PDU 14 exceeds a predetermined temperature #THNE (for example, # THNE = 70 ° C., for example) after time t1 shown in FIG. By limiting the engine speed to a predetermined upper limit speed or less (for example, in FIG. 10, the engine speed is regulated so as to maintain the predetermined upper limit speed), the temperature of the cooling water is prevented from excessively rising. As a result, the PDU 14 and the downverter 15 are in an overheated state, for example, a threshold temperature at which an overheat protection operation such as output restriction or operation stop of the PDU 14 and the downverter 15 is activated (for example, DV protection activation threshold temperature # THVV = 90 shown in FIG. 10). For example, the heat resistance of the PDU 14 and the downverter 15 is improved, or relatively high-temperature cooling water flows toward the vicinity of the PDU14 and the downverter 15, for example. The desired operation state for the PDU 14 and the downverter 15 can be continued without the need to provide a switching valve or the like for preventing this.

In the third embodiment, the predetermined upper limit rotation speed when the operation of the internal combustion engine 11 is regulated may be set according to the temperature T_DV of the downverter 15 or the temperature T_PDU of the PDU 14.
In this case, first, for example, in step S51 shown in FIG. 11, it is determined whether or not the vehicle speed (vehicle speed) V is zero.
When the determination result is “NO”, that is, when the vehicle is traveling, a series of processing is terminated.
On the other hand, when the determination result is “YES”, that is, when the vehicle is stopped, the process proceeds to Step S52.
In step S52, it is determined whether the temperature T_DV of the downverter 15 or the temperature T_PDU of the PDU 14 is higher than a predetermined temperature #THNE (for example, # THNE = 70 ° C. or the like).
When the determination result is “NO”, the series of processes is terminated.
On the other hand, if this determination is “YES”, the flow proceeds to step S53.
In step S53, for example, as shown in FIG. 12, data such as a map showing a change in the predetermined upper limit rotational speed of the engine speed according to the temperature T_DV of the downverter 15 or the temperature T_PDU of the PDU 14 is searched, and the predetermined upper limit rotational speed is searched. Set the number.
Note that the predetermined upper limit engine speed corresponding to the temperature T_DV of the downverter 15 or the temperature T_PDU of the PDU 14 is, for example, as shown in FIG. 11, each temperature T_DV, T_PDU is a predetermined first temperature # TH1 (for example, # TH1 = 70.degree. C.) to a predetermined second temperature # TH2 (for example, # TH2 = 90.degree. C.), for example, a predetermined first upper limit rotational speed # NE1 (for example, # NE1 = 3000 rpm, etc.) To a predetermined second upper limit rotational speed # NE2 (for example, # NE2 = 2500 rpm, etc.), and each temperature T_DV, T_PDU has a predetermined second temperature # TH2 (for example, # TH2 = 90 ° C.). When it exceeds, it is set to be a predetermined second upper limit rotational speed # NE2 (for example, # NE2 = 2500 rpm).
In step S54, the operation of the internal combustion engine 11 is restricted so that the engine speed is equal to or lower than the predetermined upper limit speed, and the series of processes ends.
In this case, the power storage device can be charged quickly while preventing the PDU 14 and the downverter 15 from being overheated.

Hereinafter, a fourth embodiment of the cooling device for a hybrid vehicle according to the present invention will be described with reference to the accompanying drawings.
Note that in the fourth embodiment, the description of the same portions as those of the hybrid vehicle cooling device 10 according to the first embodiment described above will be simplified or omitted. The fourth embodiment is different from the hybrid vehicle cooling device 10 according to the first embodiment described above in that, for example, as shown in FIG. 13, an eighth flow path connected to the sub flow path 22 b of the radiator 22. 30h is connected to a third flow path 30c that recirculates to the water pump 21 and the water jacket 25 of the internal combustion engine 11, and the connection angle θ between the eighth flow path 30h and the third flow path 30c is substantially equal. This is a point set at an acute angle (θ <90 °).
That is, in the fourth embodiment, the flow direction of the eighth flow path 30h intersects at a substantially acute angle with respect to the reverse direction of the flow direction of the third flow path 30c, and the eighth flow path 30h to the third flow path. The inflow of the cooling water to 30c is set so as to be suppressed by the circulation of the cooling water in the third flow path 30c.
For example, as shown in FIG. 14, when the connection angle θ between the eighth flow path 30h and the third flow path 30c is set to a substantially obtuse angle (θ> 90 °), the flow direction of the eighth flow path 30h. Is substantially at an acute angle with respect to the forward direction of the flow direction of the third flow path 30c, and the inflow of the cooling water from the eighth flow path 30h to the third flow path 30c is the cooling water in the third flow path 30c. Therefore, as the engine speed of the internal combustion engine 11 increases, the flow rate of the cooling water flowing from the eighth flow path 30h to the third flow path 30c changes in an increasing trend.
On the other hand, when the connection angle θ between the eighth flow path 30h and the third flow path 30c is set to a substantially acute angle (θ <90 °) as in the fourth embodiment, the internal combustion engine As the engine speed of the engine 11 increases, if the circulation amount of the cooling water in the third flow path 30c returning to the water pump 21 and the water jacket 25 of the internal combustion engine 11 increases, The cooling water is prevented from flowing into the three flow paths 30c.

As a result, as the engine speed (NE) of the internal combustion engine 11 increases, the flow rate of the cooling water in the third flow path 30c returning to the water pump 21 and the water jacket 25 of the internal combustion engine 11 increases, that is, the radiator. Even when the flow rate of the cooling water flowing through the interior 22 increases, the time for which the cooling water stays in the radiator 22 becomes excessively short, and the temperature of the cooling water rises, the cooling water is supplied to the PDU 14 and the downverter 15. An excessive increase in the flow rate in the eighth flow path 30h that circulates is suppressed, and the cooling water having a relatively high temperature is suppressed from being supplied to the PDU 14 and the downverter 15.
Therefore, in the fourth embodiment, for example, the heat resistance of the PDU 14 and the downverter 15 is improved, or for example, relatively high-temperature cooling water is prevented from flowing toward the vicinity of the PDU14 and the downverter 15. Even when the engine speed is increased without providing a switching valve or the like, it is possible to easily prevent the PDU 14 and the downverter 15 from being overheated.

1 is a schematic diagram of a cooling device for a hybrid vehicle according to a first embodiment of the present invention. 1 is a configuration diagram of a cooling device for a hybrid vehicle according to a first embodiment of the present invention. It is a flowchart which shows operation | movement of the cooling device of the hybrid vehicle which concerns on the 1st Embodiment of this invention. It is a flowchart which shows operation | movement of the cooling device of the hybrid vehicle which concerns on the 1st modification of the 1st Embodiment of this invention. It is a graph which shows the predetermined | prescribed 1st characteristic and 2nd characteristic with respect to the operating state of the cooling fan which concerns on the 1st modification of the 1st Embodiment of this invention. It is a block diagram of the cooling device of the hybrid vehicle which concerns on the 2nd modification of the 1st Embodiment of this invention. It is a flowchart which shows operation | movement of the cooling device of the hybrid vehicle which concerns on the 2nd modification of the 1st Embodiment of this invention. It is a flowchart which shows operation | movement of the cooling device of the hybrid vehicle which concerns on the 2nd Embodiment of this invention. It is a flowchart which shows operation | movement of the cooling device of the hybrid vehicle which concerns on the 3rd Embodiment of this invention. It is a graph which shows an example of the time change of the predetermined capacity | capacitance upper limit rotation speed of the remaining capacity SOC of the electrical storage apparatus which concerns on the 3rd Embodiment of this invention, the temperature T_DV of downverter, or the temperature T_PDU of PDU, and an engine speed. It is a flowchart which shows operation | movement of the cooling device of the hybrid vehicle which concerns on the modification of the 3rd Embodiment of this invention. It is a graph which shows the change of the predetermined | prescribed upper limit rotational speed of the engine speed according to the temperature T_DV of the downverter or the temperature T_PDU of PDU which concerns on the modification of the 3rd Embodiment of this invention. It is a block diagram of the cooling device of the hybrid vehicle which concerns on the 4th Embodiment of this invention. An example of a change in the flow rate of the eighth flow path according to the engine speed according to the fourth embodiment of the present invention is that the connection angle θ between the eighth flow path and the third flow path is an obtuse angle (θ> 90 °). It is a graph which shows according to the case where it is, and the case where it is an acute angle ((theta) <90 degree).

Explanation of symbols

10 Hybrid Vehicle Cooling Device 14 PDU (Power Control Unit)
15 Downverter (Power control means)
21 Water pump 29 Cooling fan (cooling fan for radiator)
29a Cooling fan (cooling fan for radiator)
29b Cooling fan (cooling fan for radiator)
Step S01, Step S11, Step S21 Temperature detection means Step S02, Step S13, Step S14, Step S24, Step S25 Operation control means Step S31, Step S33, Step S36 Temperature detection means Step S37 Crankshaft rotation drive means

Claims (2)

An internal combustion engine as a power source and a motor, and mounted on a hybrid vehicle capable of traveling at least by the driving force of the motor, the internal combustion engine, and power control means for controlling power supply to an in-vehicle electric device including the motor; A cooling device for a hybrid vehicle that cools the vehicle with a common cooling water,
The power control means is disposed in an engine room in which the internal combustion engine is accommodated, and is cooled by a divided cooling water in which a part of the cooling water for cooling the internal combustion engine is divided,
A radiator that cools the cooling water and the diverted cooling water, and a radiator cooling fan that promotes heat radiation from the radiator by blowing air to the radiator,
Temperature detection means for detecting the temperature of the power control means;
A hybrid vehicle cooling device comprising: an operation control unit that operates the radiator cooling fan when the temperature detected by the temperature detection unit is equal to or higher than a predetermined temperature. An internal combustion engine as a power source and a motor, and mounted on a hybrid vehicle capable of traveling at least by the driving force of the motor, the internal combustion engine, and power control means for controlling power supply to an in-vehicle electric device including the motor; A cooling device for a hybrid vehicle that cools the vehicle with a common cooling water,
The power control means is cooled by a diverted cooling water in which a part of the cooling water for cooling the internal combustion engine is diverted,
A water pump that is driven in synchronization with rotation of the crankshaft of the internal combustion engine and circulates the cooling water in the flow passage;
Temperature detection means for detecting the temperature of the power control means;
A cooling device for a hybrid vehicle, comprising: crankshaft rotation drive means for rotating the crankshaft when the temperature detected by the temperature detection means when the internal combustion engine is stopped is equal to or higher than a predetermined temperature.

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