Hybrid vehicles

Abstract

To suppress a coolant for cooling an engine from reaching a high temperature while suppressing the consumption of power stored in a battery.SOLUTION: Provided is a hybrid vehicle in which a second electric fan is disposed at a position opposite to an engine, and a second control device stops a system when ignition is turned off. In a case where the engine is stopped with the ignition turned off, and with a temperature of the engine equaling or exceeding a prescribed temperature, a first control device drives first and second electric fans. This suppresses a coolant for cooling the engine from reaching a high temperature while suppressing the consumption of power stored in a battery.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a hybrid vehicle, and more particularly to a hybrid vehicle including an engine, a motor, first and second control devices, and first and second cooling devices. [Background technology]

[0002] Conventionally, a hybrid vehicle of this type has been proposed that includes an engine, a motor (motor generator), a control unit (PCU), and first and second cooling devices (see, for example, Patent Document 1). The engine and motor output power for driving. The control unit controls the motor. The first cooling device includes a first radiator and a first electric fan (first radiator fan). The first radiator exchanges heat with a cooling medium that cools the engine. The first electric fan is used to cool the cooling medium in the first radiator. The second cooling device includes a second radiator and a second electric fan (second radiator fan). The second radiator exchanges heat with a cooling medium that cools the motor and the control unit. The second electric fan is used to cool the cooling medium in the second radiator and is controlled by the control unit. In this hybrid vehicle, when the temperature of the cooling medium in the second cooling device is equal to or higher than a predetermined temperature, the second electric fan is driven to lower the temperature of the cooling medium in the second cooling device. Furthermore, in this hybrid vehicle, even if the temperature of the cooling medium in the second cooling device is below a predetermined temperature, the second electric fan is driven when a predetermined condition is met, thereby improving the thermal environment in the engine compartment by blowing air from the second electric fan. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-119242 Summary of the Invention [Problem to be solved by the invention]

[0004] Generally, in hybrid vehicles equipped with a first control device for controlling the engine and the first electric fan and a second control device for controlling the motor and the second electric fan instead of the hybrid vehicle control device described above, when the ignition is turned off, the engine is stopped, the motor and the first and second electric fans are stopped, and the first and second control device systems are also stopped. If the engine coolant temperature is high when the ignition is turned off and the engine is stopped, the first and second electric fans are not driven, which can cause the coolant to reach a high temperature. One method to prevent this problem is to drive the first and second electric fans while the first and second control devices are active rather than shutting down the first and second control devices when the ignition is turned off. However, this method consumes a lot of power from the battery that supplies power to the first and second electric fans, the first control device, and the second control device, which can cause problems the next time the ignition is turned on.

[0005] The hybrid vehicle of the present invention has as its main object to suppress consumption of electric power stored in the battery and to suppress the temperature of the cooling medium that cools the engine from reaching a high temperature. [Means for solving the problem]

[0006] The hybrid vehicle of the present invention employs the following means to achieve the above-mentioned main object.

[0007] The hybrid vehicle of the present invention is An engine that outputs power for driving; a motor that outputs power for driving; a first control device that controls the engine; a second control device that controls the motor; a first cooling device including a first radiator that exchanges heat with a cooling medium for cooling the engine, and a first electric fan that cools the cooling medium in the first radiator; a second cooling device including a second radiator that exchanges heat with a cooling medium for cooling the motor and the second control device, and a second electric fan that cools the cooling medium of the second radiator; a battery that supplies power to the first and second control devices and the first and second electric fans; A hybrid vehicle comprising: the second electric fan is disposed at a position facing the engine, The second control device stops the system when the ignition is turned off, The first control device drives the first and second electric fans when the temperature of the engine is equal to or higher than a predetermined temperature while the engine is stopped due to an ignition off. The gist of the project is to provide the following:

[0008] In the hybrid vehicle of the present invention, the second electric fan is disposed opposite the engine, and the second control device stops the system when the ignition is off. When the engine is stopped with the ignition off and the engine temperature is equal to or higher than a predetermined temperature, the first control device drives the first and second electric fans. Driving the first electric fan suppresses the temperature rise of the engine cooling medium. Driving the second electric fan disposed opposite the engine cools the engine from the outside with airflow from the second electric fan. This suppresses the temperature rise of the engine cooling medium due to heat dissipation from the engine. Since the first control device drives the first and second electric fans, consumption of power stored in the battery is suppressed compared to when the first and second control devices drive the first and second electric fans. As a result, consumption of power stored in the battery is suppressed and the engine cooling medium is prevented from reaching high temperatures.

[0009] In the hybrid vehicle of the present invention, the first control device and the second control device may exchange information via communication, and the first control device may drive the second electric fan based on the temperature of the cooling medium in the second cooling device received from the second control device via communication when the ignition is on and there is no abnormality in the communication between the first control device and the second control device, and may drive the second electric fan when there is an abnormality in the communication between the first control device and the second control device. This prevents the motor and the second control device from reaching high temperatures when there is an abnormality in the communication between the first control device and the second control device. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a diagram showing an outline of the configuration of a hybrid vehicle 10 as an embodiment of the present invention. [Figure 2] 1 is a schematic diagram showing the general arrangement of an engine 11, a transaxle 12, radiators 23, 33, and fans 24, 34 in an engine room. [Figure 3] 4 is a flowchart showing an example of a fan control routine executed by the engine ECU 40. DETAILED DESCRIPTION OF THE INVENTION

[0011] Next, a mode for carrying out the present invention will be described using examples. [Example]

[0012] Fig. 1 is a diagram showing the general configuration of a hybrid vehicle 10 according to one embodiment of the present invention. Fig. 2 is a schematic diagram showing the general arrangement of an engine 11, a transaxle 12, radiators 23, 33, and fans 24, 34 in an engine compartment. The hybrid vehicle 10 of the embodiment includes the engine 11, the transaxle 12, a high-voltage battery 14, an auxiliary battery (battery) 15, a DC / DC converter 16, cooling devices (first and second cooling devices) 20, 30, an engine electronic control unit (hereinafter referred to as "engine ECU") (first control device) 40, and a hybrid electronic control unit (hereinafter referred to as "HVECU") (second control device) 50.

[0013] The engine 11 is configured as, for example, an internal combustion engine and outputs power for driving. As shown in Figure 2, the engine 11 is disposed in an engine compartment at the front of the hybrid vehicle 10, at a position to the left as viewed from the front of the hybrid vehicle 10.

[0014] As shown in FIGS. 1 and 2, transaxle 12 includes motor 120 and a power control unit (hereinafter referred to as "PCU") 122. As shown in FIG. 2, transaxle 12 is disposed in the engine compartment on the right side of engine 11 when viewed from the front of hybrid vehicle 10. Motor 120 is configured as, for example, a synchronous generator motor, and outputs power for traveling. PCU 122 includes an inverter that converts DC power to AC power to drive motor 120, a boost converter that boosts power from high-voltage battery 14 and supplies it to the inverter, and a microcontroller unit that controls the inverter. High-voltage battery 14 is configured as, for example, a lithium-ion secondary battery or a nickel-metal hydride secondary battery, and is connected to PCU 122 via a high-voltage power line. Auxiliary battery 15 is configured as, for example, a lithium-ion secondary battery, a nickel-metal hydride secondary battery, or a lead-acid battery, and is connected to a low-voltage power line. DC / DC converter 16 steps down the power from the high-voltage power line and supplies it to the low-voltage power line.

[0015] As shown in FIG. 1, the cooling device 20 is configured as a device for cooling the engine 11 and includes a circulation flow path 21 for coolant (cooling medium), a water pump 22, a radiator (first radiator) 23, a fan (first electric fan) 24, and a motor 35. The circulation flow path 21 is formed to include the engine 11 and the radiator 23. The water pump 22 is provided in the circulation flow path 21 and is driven using power from the auxiliary battery 15 to circulate the coolant through the circulation flow path 21. As shown in FIG. 2, the radiator 23 is disposed in front of the transaxle 12 in the engine compartment and cools the coolant through heat exchange with air generated by running and air via the fan 24. As shown in FIG. 2, the fan 24 is disposed in front of the transaxle 12, facing the transaxle 12, and behind the radiator 23. The fan 24 is rotationally driven by the motor 25 using power from the auxiliary battery 15 to blow air to the radiator 23 and cool the coolant in the radiator 23. The motor 25 is configured as, for example, a DC motor.

[0016] As shown in FIG. 1, the cooling device 30 is configured as a device for cooling the motor 120 and the PCU 122, and includes a coolant circulation flow path 31, a water pump 32, a radiator (second radiator) 33, a fan (second electric fan) 34, and a motor 35. The circulation flow path 31 is formed by including the motor 120, the PCU 122, and the radiator 33. The water pump 32 is provided in the circulation flow path 31 and is driven by power from the auxiliary battery 15 to circulate the coolant through the circulation flow path 31. As shown in FIG. 2, the radiator 33 is disposed in front of the engine 11 in the engine compartment and next to the left of the radiator 23 when viewed from the front of the hybrid vehicle 10, and cools the coolant by heat exchange with air generated by running wind and air generated by the fan 34. 2, the fan 34 is disposed in front of and facing the engine 11, and behind the radiator 33, next to the left of the fan 24, and is rotationally driven by a motor 35 using power from the auxiliary battery 15 to send air to the radiator 33 and cool the coolant in the radiator 33. The motor 35 is configured as, for example, a DC motor.

[0017] The engine ECU 40 includes a microcomputer having a CPU, ROM, RAM, flash memory, input / output ports, and communication ports (not shown), and is connected to a low-voltage power line to which the auxiliary battery 15 and the DC / DC converter 16 are connected. Various signals are input to the engine ECU 40 via an input port. Examples of the signals input to the engine ECU 40 include signals from various sensors that detect the state of the engine 11, a coolant temperature Tw1 from a water temperature sensor 27 that detects the temperature of the coolant in the cooling device 20, and an ignition signal from an ignition switch (IG) 52. Various signals are output from the engine ECU 40 via an output port. Examples of the signals output from the engine ECU 40 include various control signals for controlling the operation of the engine 11, a control signal for the water pump 22 of the cooling device 20, a control signal for the fan 24 (motor 25) of the cooling device 20, and a control signal for the fan 34 (motor 35) of the cooling device 30. The engine ECU 40 is communicatively connected to the HVECU 50 via CAN communication.

[0018] Although not shown, the HVECU 50 includes a microcomputer having a CPU, ROM, RAM, flash memory, input / output ports, and communication ports, and is connected to a low-voltage power line to which the auxiliary battery 15 and the DC / DC converter 16 are connected. Various signals are input to the HVECU 50 via an input port. Examples of the signals input to the HVECU 50 include a coolant temperature Tw2 from a water temperature sensor 37 that detects the temperature of the coolant in the cooling device 30 and an ignition signal from an ignition switch 52. Various control signals are output from the HVECU 50 via an output port. Examples of signals output from the HVECU 50 include a control signal to the DC / DC converter 16 and a control signal to the water pump 32 of the cooling device 30. As described above, the HVECU 50 is connected to the engine ECU 40 via CAN communication so as to be able to communicate with the engine ECU 40.

[0019] In the cooling system 18 thus configured and mounted on the hybrid vehicle 10 of the embodiment, the HVECU 50 basically controls the water pump 32 based on the coolant temperature Tw2 of the cooling device 30 from the water temperature sensor 37, and transmits the coolant temperature Tw2 to the engine ECU 40. The engine ECU 40 also controls the water pump 22 and the fan 24 (motor 25) based on the coolant temperature Tw1 of the cooling device 20 from the water temperature sensor 27, and controls the fan 34 (motor 35) based on the coolant temperature Tw2 of the cooling device 30 from the HVECU 50. The water pump 22 and the fan 24 are controlled to stop when the coolant temperature Tw1 is less than a threshold value (predetermined temperature) Twth12, and to operate when the coolant temperature Tw1 is equal to or greater than the threshold value Twth12. The water pump 32 and the fan 34 are basically controlled to stop when the coolant temperature Tw2 is lower than the threshold value Twth22, and to operate when the coolant temperature Tw2 is equal to or higher than the threshold value Twth22.

[0020] When the ignition switch 52 is turned off and an OFF ignition signal is received, the engine ECU 40 and the HVECU 50 basically stop the system after stopping the driving of the engine 11, the motor 120, and the PCU 122. Furthermore, when the ignition switch 52 is turned on and an ON ignition signal is received, the engine ECU 40 and the HVECU 50 basically start the system.

[0021] Next, a description will be given of the operation of the hybrid vehicle 10 of this embodiment configured as described above, in particular the control of the fan 34. Figure 3 is a flowchart showing an example of a fan control routine executed by the engine ECU 40. This routine is executed repeatedly.

[0022] When the fan control routine of FIG. 3 is executed, the engine ECU 40 first determines whether or not an ON ignition signal is received from the ignition switch 52, that is, whether or not the ignition switch 52 is ON (IG-ON) (step S100).

[0023] If the ignition switch 52 is turned on in step S100, it is then determined whether or not a communication abnormality has occurred with the HVECU 50 (step S110). This process is performed, for example, by determining whether or not communication with the HVECU 50 has been interrupted for a predetermined time. If communication with the HVECU 50 has not been interrupted for the predetermined time, it is determined that no communication abnormality has occurred with the HVECU 50, and if communication with the HVECU 50 has been interrupted for the predetermined time, it is determined that a communication abnormality has occurred with the HVECU 50.

[0024] If no communication abnormality has occurred with the HVECU 50 in step S110, the coolant temperature Tw2 is input from the HVECU 50 via CAN communication (step S120), and it is determined whether the coolant temperature Tw2 is equal to or greater than a threshold value Twth22 (step S130). If the coolant temperature Tw2 is less than the threshold value Twth22, the fan 34 is stopped (step S140), and this routine ends. If the coolant temperature Tw2 is equal to or greater than the threshold value Twth22, the fan 34 is driven (step S150), and this routine ends.

[0025] If a communication abnormality occurs with the HVECU 50 in step S110, the fan 34 is driven (step S150), and this routine ends. If a communication abnormality occurs with the HVECU 50, the coolant temperature Tw2 cannot be input from the HVECU 50 via communication. Therefore, the engine ECU 40 cannot properly determine whether the coolant circulating through the cooling device 30 is high temperature, and if the fan 34 is stopped, the motor 120 and the PCU 122 may reach high temperatures. In this embodiment, if a communication abnormality occurs between the engine ECU 40 and the HVECU 50, the fan 34 is driven, thereby preventing the motor 120 and the PCU 122 from reaching high temperatures.

[0026] If the ignition switch 52 is turned off in step S100, the engine ECU 40 executes the following process before shutting down the system.

[0027] First, the engine ECU 40 receives the coolant temperature Tw1 (step S160) and determines whether the coolant temperature Tw1 is equal to or higher than the threshold value Twth12 (step S170).

[0028] If the cooling water temperature Tw1 is less than the threshold value Twth12 in step S170, the fan 34 is stopped (step S180), and this routine ends. Since the fan 24 is stopped when the cooling water temperature Tw is less than the threshold value Twth12 as described above, step S180 is a process for stopping the fans 24, 34. When the fans 24, 34 are stopped in this manner, the engine ECU 40 performs a system shutdown. After the system is shut down in this manner, execution of this routine is suspended until the ignition switch 52 is turned on and the engine ECU 40 starts up.

[0029] If the coolant temperature Tw1 is equal to or higher than the threshold value Twth12 in step S170, the fan 34 is driven (step S190), and the routine ends. As described above, the fan 24 is driven when the coolant temperature Tw1 is equal to or higher than the threshold value Twth12, and therefore step S190 is a process for driving the fans 24, 34. Driving the fan 24 can suppress an increase in the temperature of the coolant in the cooling device 20 that cools the engine 11. Furthermore, driving the fan 34 disposed opposite the engine 11 can cool the engine 11 from the outside with the air blown by the fan 34, thereby suppressing heat dissipation from the engine 11. This suppresses an increase in the temperature of the coolant of the engine 11 due to heat dissipation from the engine 11. Meanwhile, when the ignition switch 52 is off, the HVECU 50 is in a system-stopped state, and therefore step S190 is a process for driving the fans 24, 34 by the engine ECU 40 with the HVECU 50 in a system-stopped state. Therefore, consumption of the electric power stored in the auxiliary battery 15 can be reduced compared to when both the HVECU 50 and the engine ECU 40 are started up as a system to drive the fans 24, 34. This reduces consumption of the electric power stored in the auxiliary battery 15 and also prevents the coolant that cools the engine 11 from reaching a high temperature.

[0030] According to the hybrid vehicle 10 of the embodiment described above, the fan 34 is positioned facing the engine 11, and the HVECU 50 system is stopped when the ignition is off. When the engine 11 is stopped by turning off the ignition switch 52, when the coolant temperature Tw1 is equal to or higher than the threshold value Twth12, the fans 24, 34 are driven, thereby reducing the consumption of electricity stored in the auxiliary battery 15 and preventing the coolant that cools the engine 11 from reaching high temperatures.

[0031] In the hybrid vehicle 10 of the embodiment, it is determined in step S170 whether the coolant temperature Tw1 is equal to or higher than the threshold value Twth12. However, instead of the coolant temperature Tw1, the temperature of the engine 11 may be detected, and it may be determined whether the temperature of the engine 11 is equal to or higher than a predetermined temperature.

[0032] The correspondence between the main elements of the embodiment and the main elements of the invention described in the "Means for Solving the Problem" section will be described below. In the embodiment, the engine 11 corresponds to the "engine", the motor 120 corresponds to the "motor", the engine ECU 40 corresponds to the "first control device", the HVECU 50 corresponds to the "second control device", the cooling device 20 corresponds to the "first cooling device", the cooling device 30 corresponds to the "second cooling device", and the auxiliary battery 15 corresponds to the "battery".

[0033] The correspondence between the main elements of the Examples and the main elements of the invention described in the "Means for Solving the Problem" section does not limit the elements of the invention described in the "Means for Solving the Problem" section, since the Examples are examples for specifically explaining the mode for implementing the invention described in the "Means for Solving the Problem" section. In other words, the interpretation of the invention described in the "Means for Solving the Problem" section should be based on the description in that section, and the Examples are merely specific examples of the invention described in the "Means for Solving the Problem" section.

[0034] The above describes the form for carrying out the present invention using examples, but the present invention is not limited to these examples in any way, and it goes without saying that the present invention can be carried out in various forms within the scope that does not deviate from the gist of the present invention. [Industrial Applicability]

[0035] The present invention can be used in the hybrid vehicle manufacturing industry and the like. [Explanation of symbols]

[0036] 10 Hybrid vehicle, 11 Engine, 12 Transaxle, 14 High voltage battery, 15 Auxiliary battery, 16 DC / DC converter, 18 Cooling system, 20, 30 Cooling device, 21, 31 Circulation flow path, 22, 32 Water pump, 23, 33 Radiator, 24, 34 Fan, 25, 35, 120 Motor, 27, 37 Water temperature sensor, 40 Engine electronic control unit (Engine ECU), 50 Hybrid electronic control unit (HVECU), 52 Ignition switch, 122 Power control unit (PCU).

Claims

[Claim 1] An engine that outputs power for driving; a motor that outputs power for driving; a first control device that controls the engine; a second control device that controls the motor; a first cooling device including a first radiator for exchanging heat with a cooling medium for cooling the engine, and a first electric fan for cooling the cooling medium in the first radiator; a second cooling device including a second radiator that exchanges heat with a cooling medium for cooling the motor and the second control device, and a second electric fan that cools the cooling medium of the second radiator; a battery that supplies power to the first and second control devices and the first and second electric fans; A hybrid vehicle comprising: the second electric fan is disposed at a position facing the engine, The second control device stops the system when the ignition is turned off, The first control device drives the first and second electric fans when the temperature of the engine is equal to or higher than a predetermined temperature while the engine is stopped due to an ignition off. Hybrid car.

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