vehicle

Abstract

To provide a vehicle that controls a temperature in an engine room, in which an engine and a motor power transmission mechanism are arranged, with good responsiveness.SOLUTION: A vehicle uses an engine and a motor as drive sources for travelling, and the engine and a power transmission mechanism for transmitting the power of the motor to a drive system are arranged in an engine room. The vehicle includes a first control device for controlling the engine, and a second control device for controlling the power transmission mechanism that transmits the power of the motor. The vehicle includes a first radiator through which cooling water for cooling the engine circulates, a first electric fan for cooling the first radiator, a second radiator through which cooling water for cooling the power transmission mechanism that transmits the power of the motor circulates, and a second electric fan for cooling the second radiator, and the first control device controls driving of the first electric fan and the second electric fan.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a vehicle. [Background technology]

[0002] Conventionally, vehicles have been known that use an engine and a motor as driving sources for traveling, and that include an engine cooling system that cools the engine, and a hybrid cooling system that cools a power transmission mechanism (hereinafter simply referred to as a "motor power transmission mechanism") that transmits the power of the motor to the drive system (see, for example, Patent Document 1). Also known is a cooling water temperature control device that controls the activation / deactivation of an electric water pump and an electric cooling fan based on the engine cooling water temperature, engine speed, and output torque (see, for example, Patent Document 2). Patent Document 2 states that the cooling water temperature control device may use the vehicle's engine control unit (see paragraph 0026 of Patent Document 2). Furthermore, a cooling system is known that includes a cooling control device for a rotating electric machine that activates a radiator fan 6 when the temperature of the cooling water that cools the motor generator reaches or exceeds the operating temperature (see, for example, Patent Document 3). Patent Document 3 does not mention the engine, and it is clear that the cooling control device is not a so-called engine ECU, that is, is controlled by, for example, a hybrid control device. Furthermore, it is known that the airflow rate of a cooling fan that cools a secondary battery is controlled by a hybrid control device (see, for example, Patent Document 4).

[0003] The engine cooling system and hybrid cooling system in the vehicle of Patent Document 1 each include a radiator. These radiators are arranged in the engine room (engine compartment) together with the engine and motor power transmission mechanism. The engine cooling system and hybrid cooling system each include a cooling fan for cooling the coolant flowing through each radiator. Each cooling fan is arranged opposite its corresponding radiator. The operating state of the cooling fan provided in the engine cooling system is as follows: As exemplified in Patent Document 2, The engine control unit, which executes various engine-related controls, controls the operation of the cooling fan provided in the hybrid cooling system based on, for example, the temperature of the engine coolant, the exhaust temperature, and the temperatures of components that make up the engine or are associated with the engine. As exemplified in Patent Documents 3 and 4, The hybrid control device performs power management, including recovery of power and output from the motor power transmission mechanism. The hybrid control device controls the operating state of the cooling fan based on the temperature of the hybrid cooling water that cools the transaxle and PCU (Power Control Unit) included in the motor power transmission mechanism, for example. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-119243 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-052504 [Patent Document 3] Japanese Patent Application Laid-Open No. 2014-220912 [Patent Document 4] Japanese Patent Application Laid-Open No. 2007-196876 Summary of the Invention [Problem to be solved by the invention]

[0005] The engine compartment, where the engine and motor power transmission mechanism are located, can become hot. However, the engine compartment temperature can be reduced by operating the cooling fans of the engine cooling system and hybrid cooling system. The engine is the primary heat source that increases the engine compartment temperature, and the engine compartment temperature tends to rise when the engine generates a large amount of heat. The cooling fans of the engine cooling system are controlled by the engine control device, so they can immediately start operating depending on the engine status, making it easy to respond to temperature increases in the engine compartment. On the other hand, the cooling fans of the hybrid cooling system are controlled by the hybrid control device. Therefore, to operate the cooling fans of the hybrid cooling system depending on the engine status, for example, the engine control device must issue a drive command to the hybrid control device to activate the cooling fans of the hybrid cooling system. This results in a time delay when the cooling fans of the hybrid cooling system are activated depending on the engine status. Thus, with conventional engine cooling systems and hybrid cooling systems, it has been difficult to immediately activate both cooling fans and control the temperature in the engine compartment with good responsiveness.

[0006] Therefore, the vehicle disclosed in this specification has an object to control the temperature in the engine compartment where the engine and motor power transmission mechanism are located with good responsiveness. [Means for solving the problem]

[0007] The vehicle disclosed in this specification uses an engine and a motor as driving sources for traveling, and is equipped with an engine compartment in which the engine and a power transmission mechanism that transmits the power of the motor to a drive system, a first control device that controls the engine, and a second control device that controls the power transmission mechanism that transmits the power of the motor, a first radiator through which cooling water circulates to cool the engine, a first electric fan that cools the first radiator, a second radiator through which cooling water circulates to cool the power transmission mechanism that transmits the power of the motor, and a second electric fan that cools the second radiator, and the first control device controls the drive of the first electric fan and the second electric fan.

[0008] Furthermore, in the vehicle having the above configuration, the first control device can be configured to operate the first electric fan and the second electric fan when exhaust side temperature information related to the engine is equal to or higher than a predetermined threshold value related to exhaust side temperature information.

[0009] Furthermore, in the vehicle having the above configuration, the first control device may be configured to control the first electric fan based on the temperature of the cooling water that cools the engine.

[0010] Furthermore, in a vehicle having the above configuration, the first control device can be configured to operate the first electric fan and the second electric fan when the temperature of the coolant that cools the engine is equal to or higher than a predetermined threshold value for the temperature of the coolant when the power supply of the vehicle is turned off.

[0011] Furthermore, in the vehicle having the above configuration, the second control device can be configured to request the first control device to operate the second electric fan based on the temperature of the cooling water circulating through the second radiator, and the first control device can be configured to operate the second electric fan based on the operation request. [Effects of the Invention]

[0012] According to the vehicle disclosed in this specification, the temperature in the engine compartment where the engine and motor power transmission mechanism are located can be controlled with good responsiveness. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic diagram showing a schematic configuration inside an engine room of a vehicle according to an embodiment. [Figure 2] FIG. 2 is a block diagram showing a control system for a cooling system provided in the vehicle according to the embodiment. [Figure 3] FIG. 3 is a flowchart showing an example of control of the cooling system in the vehicle according to the embodiment. [Figure 4] FIG. 4 is a graph showing an example of duty control of the engine electric fan provided in the vehicle according to the embodiment. [Figure 5] FIG. 5 is a graph showing an example of ON / OFF control of the HV electric fan provided in the vehicle according to the embodiment. [Figure 6] FIG. 6 is a flowchart showing an example of control of the cooling system when the power supply of the vehicle is turned off in the vehicle according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions and proportions of the various parts in the drawings may not be exactly the same as those in reality. In addition, some details may be omitted in the drawings.

[0015] (Embodiment) <Vehicle> First, a vehicle 1 according to this embodiment and a schematic configuration of a cooling system in the vehicle 1 will be described with reference to Figures 1 and 2. Figure 1 schematically shows the interior of an engine room 2 of the vehicle 1. In the following description, the front-rear and left-right directions of the vehicle 1 are set as shown in Figure 1. The vehicle 1 according to this embodiment is a so-called hybrid electric vehicle (HEV) of a split system (series-parallel system), and uses an engine (ENG) 3 and a motor generator (MG) 4 as driving sources for traveling. The engine 3, the motor generator 4, a transaxle (T / A) 5, and a PCU 6 are arranged in the engine room 2 of the vehicle 1.

[0016] The engine 3 in this embodiment is a gasoline engine, but may also be a diesel engine.

[0017] The motor generator 4 has a DC brushless motor and functions as both a motor and a generator. In this embodiment, the motor generator 4 is housed in a case together with a planetary gear mechanism and a differential gear, and constitutes a transaxle 5 that transmits power to the drive wheels. The transaxle 5 is provided with an oil cooler for cooling (or heating) the oil used in the transaxle 5. The PCU 6 has a built-in inverter and a microcontroller unit (microcontroller unit) for driving the motor generator 4.

[0018] The transaxle 5 and PCU 6 are included in a power transmission mechanism for transmitting the power of the motor generator 4 to a drivetrain including drive wheels (not shown). In the vehicle 1 of this embodiment, the engine 3 and the motor generator 4 are connected to a planetary gear mechanism included in the transaxle 5, and the power from the engine 3 can be divided and distributed to the motor generator 4 and the drive wheels. In addition, the power from the engine 3 and the power from the motor generator 4 can be combined and transmitted to the drive wheels. In addition, it is possible to stop the engine 3 and run the vehicle using only the power from the motor generator 4.

[0019] In this embodiment, a split-type (series-parallel type) hybrid system is employed, but the type of hybrid system is not limited to this type and may be, for example, a series type or a parallel type. In the series type, engine power is converted into electric power by a generator, and the electric power generated by the generator is used to drive a drive motor, and the power of the drive motor is transmitted to the drive wheels. In the parallel type, a power split mechanism with a planetary gear mechanism is provided, and the power of the engine and the power of the motor (motor generator) are transmitted to the drive wheels.

[0020] The vehicle 1 is equipped with an engine radiator (hereinafter referred to as the "ENG radiator") 7 through which cooling water circulates to cool the engine 3, and a hybrid radiator (hereinafter referred to as the "HV radiator") 9 through which cooling water circulates to cool the transaxle 5 and PCU 6.

[0021] The ENG radiator 7 is disposed near the right front end of the engine compartment 2. The HV radiator 9 is disposed parallel to the ENG radiator 7 in the left-right direction near the left front end of the engine compartment 2. The ENG radiator 7 corresponds to the first radiator, and the HV radiator 9 corresponds to the second radiator.

[0022] The ENG radiator 7 is connected to the engine 3 by a first pipe 7a and a second pipe 7b, and forms a coolant circulation path together with a water jacket (not shown) provided inside the engine 3. The first pipe 7a forms a path for flowing coolant from the engine 3 toward the ENG radiator 7. The second pipe 7b forms a path for flowing coolant from the ENG radiator 7 toward the engine 3. The coolant circulates between the engine 3 and the ENG radiator 7 by operation of a water pump (not shown). The engine 3 is supplied with coolant cooled by the ENG radiator 7.

[0023] The HV radiator 9 is connected to the transaxle 5 and the PCU 6 by a third pipe 9a and a fourth pipe 9b, forming a coolant circulation path between the transaxle 5 and the PCU 6. The third pipe 9a forms a path for the coolant to flow from the transaxle 5 and the PCU 6 toward the HV radiator 9. The fourth pipe 9b forms a path for the coolant to flow from the HV radiator 9 toward the transaxle 5 and the PCU 6. The coolant circulates between the transaxle 5 and the PCU 6 and the HV radiator 9 by operation of a water pump (not shown). The coolant cooled by the HV radiator 9 is supplied to the transaxle 5 and the PCU 6.

[0024] An engine electric fan (hereinafter referred to as "ENG electric fan") 8 is disposed behind the ENG radiator 7. The ENG electric fan 8 corresponds to the first electric fan and is disposed opposite the ENG radiator 7. When the ENG electric fan 8 operates, it blows air toward the ENG radiator 7, cooling the ENG radiator 7 and ultimately cooling the coolant flowing through the ENG radiator 7. The ENG electric fan 8 is controlled by pulse width modulation (PWM), in which the operating state is controlled by the duty ratio.

[0025] A hybrid electric fan (hereinafter referred to as "HV electric fan") 10 is disposed behind HV radiator 9. HV electric fan 10 corresponds to a second electric fan and is disposed opposite HV radiator 9. When HV electric fan 10 is activated, air is blown toward HV radiator 9, cooling HV radiator 9 and ultimately cooling the coolant flowing through HV radiator 9. In this embodiment, HV electric fan 10 is controlled using an ON / OFF method, in which the operating state is controlled by switching ON / OFF, but HV electric fan 10 may also be controlled using a PWM method.

[0026] Referring to FIG. 2, the ENG electric fan 8 and the HV electric fan 10 are both controlled by an engine control device (hereinafter referred to as an "ENG-ECU (Engine-Electronic Control Unit)") 11, which corresponds to a first control device. Specifically, a motor driver 8a for driving a motor 8b of the ENG electric fan 8 is electrically connected to the ENG-ECU 11, and the motor 8b is operated by a drive signal input from the ENG-ECU 11 to the motor driver 8a. Similarly, a motor driver 10a for driving a motor 10b of the HV electric fan 10 is electrically connected to the ENG-ECU 11, and the motor 10b is operated by a drive signal input from the ENG-ECU 11 to the motor driver 10a.

[0027] The ENG-ECU 11 includes a central processing unit (CPU), random access memory (RAM), read-only memory (ROM), backup RAM, and other storage devices. The ENG-ECU 11 performs arithmetic processing and various control operations based on programs and maps stored in the CPU, ROM, and other storage devices. The RAM temporarily stores the results of CPU calculations and data input from various sensors, while the backup RAM is a non-volatile memory that stores data to be saved when the engine 3 is stopped. The ENG-ECU 11 is connected to sensors for controlling the ENG electric fan 8 and the HV electric fan 10. Specifically, the ENG-ECU 11 is connected to a first water temperature sensor 21 that measures the temperature of the coolant circulating within the engine 3 and an exhaust temperature sensor 22 that measures the temperature of the exhaust gas discharged from the engine 3. The ENG-ECU 11 also includes a voltmeter 23 that measures the voltage applied to the ENG-ECU 11 and a timer 24 that measures the elapsed time since the vehicle 1 was powered off.

[0028] Note that the ENG-ECU 11 executes various controls related to the operation of the engine 3, such as controlling the opening degree of a throttle valve (not shown) that adjusts the intake air volume of the engine 3, and controlling the opening and closing of intake valves and exhaust valves (both not shown). For this reason, sensors for performing various controls other than the control of the ENG electric fan 8 and the HV electric fan 10 are connected to the ENG-ECU 11, and various programs and various maps are stored therein. However, the description thereof is omitted here.

[0029] Separate from the ENG-ECU 11, the vehicle 1 includes a hybrid control device (hereinafter referred to as "HEV-ECU (Hybrid Electric Vehicle - Electronic Control Unit)") 12. The HEV-ECU 12 corresponds to a second control device that controls the transaxle 5 and the PCU 6. Since the transaxle 5 and the PCU 6 are unitized separately from the engine 3, the HEV-ECU 12 is also provided separately from the ENG-ECU 11. Power management including output and power recovery in the transaxle 5 and the PCU 6 is performed. The HEV-ECU 12 includes a CPU, a RAM, a ROM, a backup RAM, and other storage devices. However, since its basic configuration is the same as that of the ENG-ECU 11, the detailed description thereof is omitted here.

[0030] A second water temperature sensor 25 for measuring the temperature of the cooling water circulating between the transaxle 5 and the PCU 6 and the HV radiator 9 is connected to the HEV-ECU 12. The HEV-ECU 12 is capable of communicating with the ENG-ECU 11 via CAN (Controller Area Network) communication, and makes an operation request for the HV electric fan 10 to the ENG-ECU 11 based on the measured value of the second water temperature sensor 25. The ENG-ECU 11 operates the HV electric fan 10 based on the operation request for the HV electric fan 10 from the HEV-ECU 12. Thus, the HV electric fan 10 may also operate based on the operation request of the HEV-ECU 12.

[0031] <Control of ENG Electric Fan and HV Electric Fan> Here, the circumstances and ways in which the ENG electric fan 8 and the HV electric fan 10 operate will be explained with reference to Table 1. [Table 1]

[0032] First, we will explain the case where the power supply to the vehicle 1 is ON. When the power supply to the vehicle 1 is ON, the ignition is ON, power is supplied to each part of the vehicle 1, and the engine 3 is running or can run. In this case, when the temperature of the engine components is high, the ENG electric fan 8 operates in the HI state, and the HV electric fan 10 is ON, i.e., in operation.

[0033] Here, the engine component temperature may be the temperature of a component in the engine 3 that is likely to become hot, specifically, the surface temperature of the exhaust catalyst or the exhaust manifold, or in some cases, the exhaust temperature. The surface temperatures of the exhaust catalyst or the exhaust manifold and the exhaust temperature are examples of exhaust-side temperature information. The exhaust-side temperature information is referenced because exhaust-related temperatures have a significant impact on the temperature in the engine compartment 2. The exhaust-side temperature information is included in the index for determining the state of the engine 3, and control may be performed based on other values ​​that are correlated with these temperatures. In this embodiment, the exhaust temperature Tex of the engine 3 measured by the exhaust temperature sensor 22 is used. In this embodiment, the exhaust temperature Tex is measured and acquired by the exhaust temperature sensor 22. However, the exhaust temperature Tex may also be acquired based on the operating state of the engine 3, which is determined by the amount of intake air of the engine 3, for example, using a map. In this embodiment, the engine component temperature is determined to be high when the exhaust temperature Tex is equal to or higher than a predetermined exhaust temperature threshold Texth. Of the temperatures related to the engine 3, the exhaust temperature Tex is the one that tends to become high. Therefore, by performing control based on the exhaust temperature Tex, it becomes easier to control the temperature in the engine compartment 2 with good responsiveness.

[0034] In this embodiment, the ENG electric fan 8 being in the HI state refers to a state in which the ENG electric fan 8 is operated at a duty ratio of 100%. That is, in this embodiment, when the exhaust temperature Tex is equal to or higher than the threshold value Texth, the ENG electric fan 8 is operated at a duty ratio of 100%. However, the ENG electric fan 8 being in the HI state does not necessarily have to be operated at a duty ratio of 100%; the duty ratio may be set appropriately, for example, to 95% or higher.

[0035] In this embodiment, when the exhaust gas temperature Tex is equal to or higher than the threshold Texth, the ENG electric fan 8 is operated in the HI state and the HV electric fan 10 is operated in the ON state. When the exhaust gas temperature Tex is equal to or higher than the threshold Texth, which indicates that the engine component temperatures are high, the temperature in the engine compartment 2 is likely to rise. The temperature in the engine compartment 2 is likely to affect the operation of the PCU 6 and other components located in the engine compartment 2. Therefore, when the temperature in the engine compartment 2 is likely to rise, the HV electric fan 10 is immediately operated along with the ENG electric fan 8 to lower the temperature in the engine compartment 2 or suppress the temperature rise. If the HV electric fan 10 were configured to operate in response to an operation command from the HEV-ECU 12, the ENG-ECU 11, having acquired the exhaust gas temperature Tex, would have to issue an operation request to the HEV-ECU 12, which would delay the start of operation of the HV electric fan 10. In this embodiment, the ENG electric fan 8 and the HV electric fan 10 are activated immediately, so the temperature in the engine compartment 2 can be controlled with good responsiveness.

[0036] Next, we will explain the case where the vehicle 1 is powered on and the engine coolant temperature Tengw is high, i.e., the engine coolant temperature Tengw is equal to or higher than a predetermined threshold value Tengwth. In this case, the ENG electric fan 8 is duty-ratio controlled in accordance with the engine coolant temperature Tengw. Note that in this case, the HV electric fan 10 column in Table 1 is left blank. This means that the HV electric fan 10 is not controlled by the engine coolant temperature Tengw, but does not mean that the HV electric fan 10 does not operate when the engine coolant temperature Tengw is high. As will be explained next, the HV electric fan 10 operates when the PCU coolant temperature Tpcuw is high, regardless of the engine coolant temperature Tengw.

[0037] Next, we will explain the case where the vehicle 1 is powered on and the PCU coolant temperature Tpcuw is high, i.e., the PCU coolant temperature Tpcuw is equal to or higher than a predetermined threshold Tpcuwth. In this case, the HV electric fan 10 is turned on in response to the PCU coolant temperature Tpcuw. Note that in this case, the ENG electric fan 8 column in Table 1 is left blank. This means that the ENG electric fan 8 is not controlled by the PCU coolant temperature Tpcuw, but does not mean that the ENG electric fan 8 will not operate when the PCU coolant temperature Tpcuw is high.

[0038] Next, a description will be given of a case where the vehicle 1 is powered off. When the vehicle 1 is powered off, it is expected that the temperature in the engine compartment 2 will increase depending on the vehicle 1's previous operating conditions. Therefore, in this embodiment, if the engine coolant temperature Tengw is equal to or higher than a predetermined threshold Tengwth' when the vehicle 1 is powered off, the ENG electric fan 8 is operated in the HI state and the HV electric fan 10 is operated in the ON state. By immediately operating the ENG electric fan 8 and the HV electric fan 10 in this manner, it is possible to reduce or suppress the temperature rise in the engine compartment 2. If the temperature in the engine compartment 2 increases during the soak period after the engine 3 is stopped, fuel remaining in the delivery pipe and injectors (neither of which is shown) that supply fuel to the engine 3 may boil. If the fuel boils, a misfire may occur due to the so-called air entrapment phenomenon in the fuel when the engine is restarted after the soak period. By operating the ENG electric fan 8 and the HV electric fan 10 when the vehicle 1 is powered off and responsively controlling the temperature in the engine compartment 2, this phenomenon can be avoided.

[0039] In Table 1, when the ENG electric fan 8 is driven at HI, the ENG electric fan 8 is operated at a duty ratio of 100%. However, the duty ratio may be varied in accordance with the exhaust temperature Tex or the engine coolant temperature Tengw, i.e., the duty ratio may be increased as these temperatures increase, for more precise control.

[0040] Next, a specific example of control of the engine electric fan 8 and the hybrid electric fan 10 will be described with reference to Figures 3 to 6. For the sake of convenience, it is assumed that the engine electric fan 8 and the hybrid electric fan 10 are not operating at the start of control.

[0041] <When the vehicle's power is ON> First, the case where the power supply to the vehicle 1 is ON will be described with reference to the flowchart shown in FIG. 3. In step S1, the ENG-ECU 11 determines whether the exhaust temperature Tex, which is the measurement value of the exhaust temperature sensor 22, is equal to or higher than a predetermined threshold value Texth. If the ENG-ECU 11 makes a positive determination (Yes determination) in step S1, the ENG-ECU 11 proceeds to step S2. In step S2, the ENG-ECU 11 activates the ENG electric fan 8 and the HV electric fan 10. This enables the temperature in the engine compartment 2 to be controlled with good responsiveness. After executing step S2, the ENG-ECU 11 repeats the process from step S1.

[0042] If the ENG-ECU 11 makes a negative determination (No determination) in step S1, the ENG-ECU 11 proceeds to step S3. In step S3, the ENG-ECU 11 determines whether the engine coolant temperature Tengw is equal to or higher than a threshold value Tengwth. If the ENG-ECU 11 makes a positive determination in step S3, the ENG-ECU 11 proceeds to step S4, whereas if the ENG-ECU 11 makes a negative determination in step S3, the ENG-ECU 11 skips step S4 and proceeds to step S5.

[0043] In step S4, the ENG-ECU 11 operates the ENG electric fan 8. An example of the operation control of the ENG electric fan 8 executed in step S4 will now be described with reference to FIG.

[0044] 4, when engine coolant temperature Tengw is lower than threshold value Tengwth, the duty ratio of ENG electric fan 8 is 0%, and ENG electric fan 8 is stopped. As engine coolant temperature Tengw rises from this state and reaches threshold value Tengwth, ENG-ECU 11 sets the duty ratio of ENG electric fan 8 to 30%. As engine coolant temperature Tengw approaches temperature Tengwth+1, which is 1°C higher than threshold value Tengwth, ENG-ECU 11 gradually increases the duty ratio, setting it to 70% at temperature Tengwth+1. When engine coolant temperature Tengw reaches temperature Tengwth+3, which is 3°C higher than threshold value Tengwth, ENG-ECU 11 sets the duty ratio to 100%.

[0045] On the other hand, when the engine coolant temperature Tengw drops from temperature Tengwth+3 to temperature Tengwth+1, the ENG-ECU 11 reduces the duty ratio from 100% to 70%. Furthermore, while the engine coolant temperature Tengw drops from temperature Tengwth+1 to the threshold value Tengwth, the ENG-ECU 11 gradually reduces the duty ratio from 70% to 30%. When the engine coolant temperature Tengw drops from the threshold value Tengwth to temperature Tengwth-2, which is 2°C lower than the threshold value Tengwth, the ENG-ECU 11 reduces the duty ratio from 30% to 0%. The difference between the temperatures at which the duty ratio is increased and decreased is intended to prevent hunting in the control. After a positive determination is made in step S3, the operation of the ENG electric fan 8 continues based on the duty ratio control shown in the graph in FIG. 4. The duty ratios shown in FIG. 4 are merely examples and may be changed as appropriate.

[0046] After the ENG-ECU 11 starts the operation of the ENG electric fan 8 in step S4 or after making a negative determination in step S3, the ENG-ECU 11 proceeds to step S5. In step S5, the HEV-ECU 12 determines whether the PCU coolant temperature Tpcuw is equal to or higher than a threshold value Tpcuwth. If the HEV-ECU 12 makes a positive determination in step S5, the HEV-ECU 12 proceeds to step S6. On the other hand, if the HEV-ECU 12 makes a negative determination in step S5, the HEV-ECU 12 repeats the process from step S1.

[0047] In step S6, the HEV-ECU 12 operates the HV electric fan 10. An example of the operation control of the ENG electric fan 8 executed in step S4 will now be described with reference to FIG.

[0048] Referring to Figure 5, when PCU coolant temperature Tpcuw is lower than threshold value Tpcuwth, HV electric fan 10 is in the OFF state and is stopped. When PCU coolant temperature Tpcuw rises from this state and reaches threshold value Tpcuwth, HEV-ECU 12 turns on the drive signal for HV electric fan 10. This ON signal is transmitted from HEV-ECU 12 to ENG-ECU 11 via CAN communication as a request to operate HV electric fan 10. Upon receiving this ON signal, ENG-ECU 11 operates HV electric fan 10.

[0049] On the other hand, when the PCU coolant temperature Tpcuw drops to a temperature Tpcuwth-2 that is 2° C. lower than the threshold value Tpcuwth, the HEV-ECU 12 turns off the drive signal for the HV electric fan 10. This OFF signal is transmitted from the HEV-ECU 12 to the ENG-ECU 11 via CAN communication as a request to stop the HV electric fan 10. Upon receiving this OFF signal, the ENG-ECU 11 stops the HV electric fan 10.

[0050] Here, activation of the HV electric fan 10 in step S6 is performed via CAN communication between the ENG-ECU 11 and the HEV-ECU 12. Therefore, activation of the HV electric fan 10 in step S6 may be delayed compared to activation of the HV electric fan 10 in step S2. This is because activation of the HV electric fan 10 in step S6 is considered less important in terms of immediacy than activation of the HV electric fan 10 in step S2. The reason for this is explained below. First, activation of the HV electric fan 10 in step S2 is based on the need to control the temperature in the engine compartment 2 with good responsiveness. More specifically, activation of the HV electric fan 10 in step S2 is due to the temperature rise in the engine compartment 2 caused by operation of the engine 3, which has a rapid temperature rise rate and a large heat capacity. In contrast, activation of the HV electric fan 10 in step S6 is primarily intended to cool the HV radiator 9. Therefore, even if the activation of HV electric fan 10 in step S6 is slightly delayed compared to the activation of HV electric fan 10 in step S2, it does not pose a significant problem. For the above reasons, this embodiment employs a configuration in which HV electric fan 10 is activated by ENG-ECU 11.

[0051] Note that CAN communication is an example of a communication means between the ENG-ECU 11 and the HEV-ECU 12, and other communication means may be employed.

[0052] After step S6 is executed, the control of the vehicle 1 is repeated from step S1. After a positive determination is made in step S5, the operation of the HV electric fan 10 continues based on the ON / OFF control shown in the graph in FIG.

[0053] <When the vehicle's power is off> Next, with reference to FIG. 6, a case where the power supply of the vehicle 1 is turned off will be described. First, in step S11, the ENG-ECU 11 determines whether the power supply of the vehicle 1 is turned off and whether the voltage applied to the ENG-ECU 11 is equal to or greater than a reference value VO [V]. The voltage applied to the ENG-ECU 11 is a value measured by the voltmeter 23. The voltage applied to the ENG-ECU 11 is determined in order to determine whether the ENG-ECU 11 is in a state where it can execute a predetermined calculation. If the ENG-ECU 11 makes a positive determination in step S11, the ENG-ECU 11 proceeds to step S12. On the other hand, if the ENG-ECU 11 makes a negative determination in step S11, the ENG-ECU 11 ends the processing (END). In conjunction with the execution of step S11, the ENG-ECU 11 starts counting the elapsed time t since the power supply of the vehicle 1 was turned off using the timer 24.

[0054] In step S12, the ENG-ECU 11 determines whether the engine coolant temperature Tengw immediately before the power of the vehicle 1 is turned off is equal to or higher than the threshold value Tengwth'. If the determination in step S12 is affirmative, the ENG-ECU 11 proceeds to step S13, whereas if the determination in step S12 is negative, the ENG-ECU 11 ends the processing (END).

[0055] In step S13, the ENG-ECU 11 activates the ENG electric fan 8 and the HV electric fan 10. This allows for responsive control of the temperature inside the engine compartment 2. After the vehicle 1 is powered off, the ENG electric fan 8 and the HV electric fan 10 are operated using an auxiliary battery (not shown) as a power source.

[0056] In step S14, which follows step S13, the ENG-ECU 11 determines whether the elapsed time t since the vehicle 1 was powered off is equal to or greater than a predetermined reference time t0 [sec]. If the ENG-ECU 11 determines yes in step S14, it proceeds to step S15. If the ENG-ECU 11 determines no in step S14, it repeats the process of step S14. In step S15, the ENG-ECU 11 stops the ENG electric fan 8 and the HV electric fan 10. The reason for stopping the ENG electric fan 8 and the HV electric fan 10 when the elapsed time t exceeds the reference time t0 [sec] is to prevent the auxiliary battery from deteriorating if these electric fans are operated for a long period of time. The reference time t0 [sec] is set in consideration of the degree of deterioration of the auxiliary battery when the ENG electric fan 8 and the HV electric fan 10 are operated by the auxiliary battery. In step S15, ENG-ECU 11 stops ENG electric fan 8 and HV electric fan 10, and then ends the series of processes (END).

[0057] In the vehicle 1 of this embodiment, the ENG electric fan 8 and the HV electric fan 10 are operated for a certain period of time after the power of the vehicle 1 is turned off, so that the temperature in the engine compartment 2 can be controlled with good responsiveness even after the power of the vehicle 1 is turned off.

[0058] In the vehicle 1 of this embodiment, the ENG-ECU 11 controls the driving of the ENG electric fan 8 and the HV electric fan 10, so that the temperature in the engine compartment 2 can be controlled with good responsiveness.

[0059] The vehicle 1 of this embodiment controls both the ENG electric fan 8 and the HV electric fan 10 based on the state of the engine 3, making it easy to control the temperature in the engine compartment 2 with good responsiveness.

[0060] In the vehicle 1 of this embodiment, when the exhaust temperature Tex of the engine 3, which tends to become high, is equal to or higher than a predetermined threshold Texth, the ENG electric fan 8 and the HV electric fan 10 are driven, thereby enabling more responsive control of the temperature in the engine compartment 2.

[0061] In the vehicle 1 of this embodiment, the engine electric fan 8 is controlled based on the coolant temperature Tengw of the engine 3, so that the engine electric fan 8 can be operated based on the coolant temperature Tengw regardless of the exhaust temperature Tex and the like.

[0062] In the vehicle 1 of this embodiment, when the power supply to the vehicle 1 is turned off, the ENG-ECU 11 operates the ENG electric fan 8 and the HV electric fan 10 if the engine coolant temperature Tengw is equal to or higher than the threshold value Tengwth'. This allows the temperature in the engine compartment 2 to be controlled with good responsiveness even after the power supply to the vehicle 1 is turned off.

[0063] In vehicle 1 of this embodiment, HEV-ECU 12 requests ENG-ECU 11 to operate HV electric fan 10 based on PCU coolant temperature Tpcuw. ENG-ECU 11 then operates HV electric fan 10 based on the operation request. Therefore, regardless of the state of engine 3, HV electric fan 10 can be operated based on PCU coolant temperature Tpcuw.

[0064] The above-described embodiments are merely examples for implementing the present invention, and the present invention is not limited to these. Various modifications of these embodiments are within the scope of the present invention. Furthermore, it is obvious from the above description that various other embodiments are possible within the scope of the present invention. [Explanation of symbols]

[0065] 1 vehicle 2 Engine Room 3 Engine 4 Motor generator 5 Transaxle 6 PCU 7 ENG radiator (first radiator) 8 ENG electric fan (first electric fan) 9 HV radiator (second radiator) 10 HV electric fan (second electric fan) 11 ENG-ECU (first control unit) 12 HEV-ECU (second control unit) 21 First water temperature sensor 22 Exhaust gas temperature sensor 25 Second water temperature sensor

Claims

1. A vehicle using an engine and a motor as driving sources for traveling, the engine and a transaxle that transmits power of the motor to drive wheels are disposed in an engine room, and the vehicle is equipped with a first control device that controls the engine and a second control device that controls the transaxle that transmits power of the motor, a first radiator through which cooling water for cooling the engine circulates; a first electric fan that cools the first radiator; a second radiator through which cooling water circulates to cool a transaxle that transmits power from the motor; a second electric fan that cools the second radiator; Equipped with the first control device controls the driving of the first electric fan and the second electric fan, and when exhaust side temperature information related to the engine becomes equal to or higher than a predetermined threshold value related to exhaust side temperature information, issues an operation command to the first electric fan and the second electric fan at the same timing. vehicle.

2. 2. The vehicle according to claim 1, wherein the first control device controls the first electric fan based on the temperature of a coolant that cools the engine.

3. 3. The vehicle according to claim 1, wherein the first control device operates the first electric fan and the second electric fan when the temperature of the coolant that cools the engine is equal to or higher than a predetermined threshold value for the temperature of the coolant when the power of the vehicle is turned off.

4. 4. The vehicle according to claim 1, wherein the second control device requests the first control device to operate the second electric fan based on the temperature of the cooling water circulating through the second radiator, and the first control device operates the second electric fan based on the operation request.

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