Control system for a hybrid vehicle

Abstract

Control system for a hybrid vehicle (10), the control system comprising: an internal combustion engine (14) for powering the vehicle (10); an electric motor (16, 18) for powering the vehicle (10); a battery (26) configured to receive electrical power from and to supply electrical power to the electric motor (16, 18); a radiator fan (36) configured to cool the battery (26);and a controller (38) configured to determine the operation of the cooling fan (36) based on the charged / discharged electrical power of the battery (26) and the presence or absence of a charging request during operation of the hybrid vehicle (10), wherein the charging request is based on a user's intention, wherein the controller (38) is configured to control the operation of the cooling fan (36) such that the battery (26) with the same charged / discharged electrical power is cooled more in a case below i) than in a case below ii), i) the charging request is present, and ii) the charging request is not present.

Description

BACKGROUND OF THE INVENTION 1. Field of the invention The invention relates to a control system for a hybrid vehicle comprising an internal combustion engine and an electric lathe for powering the vehicle, and in particular a control system for cooling a battery that receives electrical power from the electric lathe and transmits electrical power to the electric lathe. 2. Description of the state of the art A vehicle comprising an internal combustion engine and an electric rotary engine as its main propulsion systems, i.e., a so-called hybrid vehicle, is known. In this specification, "electric rotary engine" is used as a collective term for a motor, a generator, and other electrical equipment that functions as both the motor and the generator. The hybrid vehicle has a battery that receives electrical power from or transmits it to the electric rotary engine. The following Japanese patent application publication No. 2014-189147 (JP 2014-189147 A) discloses a hybrid vehicle in which the battery's power storage capacity is increased in response to a request from a vehicle user (for example, a driver). In cases where an increase in power storage is requested and the battery is therefore charged, there is a high probability that the vehicle will subsequently be driven using only the electric motor. During this driving phase, the electric motor's output increases. Consequently, the battery generates heat as a result of the large amount of electrical power supplied to the electric motor, thus raising its temperature. Publication JP 2005 / 204481A discloses a control device for controlling a cooling fan of an energy storage mechanism mounted on a vehicle and connected to a rotating electric machine for operating the vehicle. The control device comprises sensing means for detecting the vehicle's driving mode, temperature sensing means for detecting the temperature of the energy storage mechanism, and control means for controlling the cooling fan based on the driving mode and the temperature of the energy storage mechanism. Publication JP 2008 / 278705A discloses a cooling fan for cooling the secondary battery in a hybrid or electric vehicle, wherein the temperature of the secondary battery increases with repeated charging / discharging. The temperature increase of the secondary battery increases with increasing charging / discharging current, so that the volume of air required for cooling becomes larger when the charging / discharging current of the secondary battery is high, and the volume of air required for cooling becomes smaller when the charging / discharging current of the secondary battery is low. SUMMARY OF THE INVENTION The invention provides a control system that suppresses a temperature increase of a battery during a journey after charging the battery based on a request from a vehicle user or during a journey for which only the use of an electric lathe is predicted. One aspect of a control system relating to the present invention comprises an internal combustion engine, an electric lathe, a battery, a radiator fan, and a controller. The internal combustion engine serves to power the vehicle. The electric lathe also serves to power the vehicle. The battery is configured to receive electrical power from and supply electrical power to the electric lathe. The radiator fan is configured to cool the battery. The controller is configured to determine the operation of the radiator fan based on the charged / discharged electrical power of the battery and the presence or absence of a charging request during operation of the hybrid vehicle, wherein the charging request is based on a user's intention.The controller is configured to regulate the operation of the cooling fan so that the battery, with the same charged / discharged electrical power, is cooled more in case i) than in case ii); i) a charging request is present, ii) a charging request is not present. According to this control system, the cooling fan is operated to further cool the battery in preparation for high-output operation of the electric lathes after a charging request is made based on the user's intent. As a result, a temperature increase in the battery can be suppressed. That is, according to this control system, if the electric lathes are to be operated at high output in the future, the temperature increase of the battery during the high-output operation is suppressed in advance by preventing the temperature increase from occurring.Another aspect of the control system relating to the present invention comprises an internal combustion engine, an electric lathe, a battery, a cooling fan, a switch, and a controller. The internal combustion engine serves to power the vehicle. The electric lathe also serves to power the vehicle. The battery is configured to receive electrical power from and supply electrical power to the electric lathe. The cooling fan is configured to cool the battery. The switch is configured to issue a command to increase the battery's power storage capacity while the hybrid vehicle is in operation. The controller is configured to determine the operation of the cooling fan based on the battery's charge / discharge electrical power and the switch's on / off state.The controller is configured to regulate the operation of the cooling fan so that the battery, with the same charged / discharged electrical power, is cooled more in case i) than in case ii); i) the switch is in the ON state and ii) the switch is in the OFF state. According to this control system, the cooling fan operates, thus cooling the battery more effectively to prepare it for high-output operation of the electric lathe after the switch is turned to the ON state. As a result, the battery temperature increase can be suppressed. That is, according to this control system, if the electric lathes are to be operated at high output in the future, the battery temperature increase during high-output operation is suppressed in advance by preventing it. Furthermore, another aspect of a control system relating to the present invention comprises an internal combustion engine, an electric lathe, a battery, a radiator fan, and a control unit. The internal combustion engine serves to power the vehicle. The electric lathe also serves to power the vehicle. The battery is configured to receive electrical power from and to supply electrical power to the electric lathe. The radiator fan is configured to cool the battery.The controller is configured to predict whether a drive will be undertaken solely by the electric motor in the future while the hybrid vehicle is operating, and is configured to determine the operation of the radiator fan based on the charged-discharged electrical power of the battery and a prediction of the drive being solely by the electric motor. The controller is configured to control the operation of the radiator fan so that the battery is cooled more with the same charged-discharged electrical power in case i) than in case ii); i) the drive being solely by the electric motor is predicted and ii) the drive being solely by the electric motor is not predicted.According to the control system for this aspect, if only the electric lathe is expected to operate, the cooling fan will activate to cool the battery more effectively in preparation for the high-output operation of the electric lathe at that time. As a result, the expected battery temperature increase can be suppressed. In other words, according to this control system, if the electric lathes are likely to operate at high output in the future, the battery temperature increase during such operations will be prevented by preemptively suppressing it. The controller can be configured to set a lower temperature limit at which the cooling fan operates, in case i) lower than in case ii). Because cooling by the cooling fan is performed from a state in which the battery temperature is low, the temperature increase of the battery can be suppressed. The controller can be configured to regulate the airflow or volume of the cooling fan, so that in case i) it is larger than in case ii). Because the airflow to the battery is increased, the temperature increase of the battery is suppressed. The controller can be configured to maintain a vehicle speed, and the controller can be configured to increase the airflow of the radiator fan when the vehicle speed increases, as in case i). The controller can be configured to receive an output from the internal combustion engine. The controller can be configured to increase the airflow of the radiator fan when the output of the internal combustion engine increases, as in case i). The hybrid vehicle can be configured to operate by switching between an EV mode and an HV mode. The EV mode can be a mode in which the vehicle is powered solely by the electric motor. The HV mode can be a mode in which the vehicle is powered selectively by either the electric motor or the internal combustion engine, depending on the situation. The control system can be configured to increase the airflow from the radiator fan when an output from the internal combustion engine increases, as in the case of i) and the vehicle is operating in HV mode. According to the control system of any of the above aspects, if the electric lathes may be operated at high output in the future, such as when the user requests battery charging, the switch is in the "on" state to instruct an increase in the power storage amount, and the prediction of driving by only the electric lathes, the temperature increase of the battery during high output operation will be suppressed by suppressing the temperature increase of the battery before the high output operation. BRIEF DESCRIPTION OF THE DRAWINGS Features, advantages, and a technical and industrial significance of exemplary embodiments of the invention are described below with reference to the accompanying drawings, in which the same reference numerals denote the same elements and in which: Fig. 1 shows a schematic configuration of a vehicle according to the invention; Fig. 2 shows a diagram of an example of an air volume control for reducing a lower operating limit temperature of a radiator fan; Fig. 3 shows a diagram of an example of an air volume control for increasing the air volume of the radiator fan; Fig. 4 shows a diagram of an example of an air volume control for increasing the air volume of the radiator fan in response to an increase in vehicle speed; Fig. 5 shows a diagram of an example of an air volume control for increasing the air volume of the radiator fan in response to an increase in vehicle speed and an increase in the output of an internal combustion engine; Fig.Figure 6 shows a diagram of an example processing sequence for adjusting the airflow of the radiator fan; Figure 7 shows a diagram of an example processing sequence for adjusting the airflow of the radiator fan; Figure 8 shows a diagram of an example processing sequence for adjusting the airflow of the radiator fan; Figure 9 shows a diagram of an example processing sequence for adjusting the airflow of the radiator fan; and Figure 10 shows a diagram of a change in a power storage amount during a journey of the vehicle. DETAILED DESCRIPTION OF EXAMPLES OF EXECUTION The following is a description of an embodiment of the invention according to the drawings. Fig. 1 shows a schematic configuration of a vehicle 10 according to the invention. The vehicle 10 is a so-called plug-in hybrid vehicle, which can be charged by an external power supply, such as a commercial power supply. A power unit 12 for driving the vehicle 10 comprises an internal combustion engine 14 and two units of electric motors 16, 18 as the main drive motors for propelling the vehicle. The power unit 12 further includes a power distribution device 22, which facilitates power transfer between the three units of the main drive motors 14, 16, and 18 and between each of these main drive motors and drive wheels 20.The power-splitting device 22 comprises a planetary gear unit, wherein an electric lathe 16 is connected to a solar element of the planetary gear unit, the internal combustion engine 14 is connected to a planetary element, and the other electric lathe 18 is connected to a ring element. The electric lathe 16 connected to the solar element is described as the first electric lathe 16, and the electric lathe 18 connected to the ring element is described as the second electric lathe 18. The ring element is connected to the drive gears 20 via a reduction mechanism provided in the power-splitting device 22. Electrical power is supplied from a battery 26 to the first and second electric lathes 16, 18 via a power converter 24.Additionally, the electrical power generated by the first and second electric lathes 16, 18 is stored in the battery 26. The power converter 24 includes an inverter that converts DC power supplied by the battery 26 into AC power, and conversely, converts the AC power generated by the first and second electric lathes 16, 18 into DC power. The battery 26 is, for example, a secondary battery. The power-splitting device 22 can split the output of the internal combustion engine 14 into an output for driving the first electric lathe 16 and an output that is transmitted to the drive wheels 20 to propel the vehicle. Simultaneously, the first electric lathe 16 acts as a generator, and the generated power is stored in the battery 26. The power-splitting device 22 can simultaneously transmit the output of the internal combustion engine 14 and the output of the second electric lathe 18 to the drive wheels 20. Additionally, the second electric lathe 18 can act as a generator when it is driven by the inertial force of the vehicle via the drive wheels 20. The generated power is stored in the battery 26.This is a so-called regenerative braking system, in which a vehicle's speed is reduced by converting the vehicle's kinetic energy into electrical energy. The configuration of the power device 12 is not limited to the configuration described above. For example, the power device 12 can be configured such that the internal combustion engine drives the generator, and the vehicle is driven by a motor powered by the generated electrical power. In this case, the internal combustion engine and generator do not directly drive the vehicle; however, they contribute indirectly to driving the vehicle by supplying electrical power to the motor that drives the vehicle. Here, such primary drive units (the internal combustion engine and the generator) are included as the primary drive units for driving the vehicle. Additionally, the power device 12 can be constructed from a unit of internal combustion engine and a unit of electric motor. An operating mode in which the vehicle is powered solely by the electric motors is described below as an "EV mode." An operating mode in which the vehicle uses both the electric motors and the internal combustion engine is referred to as an "HV mode." In HV mode, based on the vehicle's driving status, such as vehicle speed, battery charge level, and driver request, the vehicle is powered either by separate use of the electric motors and the internal combustion engine, or by simultaneous use of both. Similarly, in HV mode, the vehicle is powered by the electric motors only, for example, during low-speed driving.However, during low-speed driving, the vehicle is in a state where the internal combustion engine is started according to its status. Therefore, driving in this case, where only the electric motor is used, is not considered EV mode. In vehicle 10, the battery 26 can be charged by an external power supply 28. A charging connector 32, connected to the external power supply 28, is connected to a charging port 30 provided on vehicle 10. Charging is thus carried out via a charger 34. Additionally, a cooling fan 36 is provided to cool the battery 26. The vehicle 10 has a control unit 38 for controlling the operations of the internal combustion engine 14 and the first and second electric motors 16, 18 based on a request from a vehicle user (a driver, for example) and the vehicle's status. The driver's request can be understood as based on operations of an accelerator pedal, a brake pedal, a gearshift lever, and the like. The vehicle's status can be determined, for example, by the vehicle's speed, the amount of stored power, and the temperature of the battery 26, and similar information. The vehicle speed can be detected by a vehicle speed sensor 40, which detects the rotational speed of the drive wheel 20, or by an element that rotates with it in a specific rotational relationship.The controller 38 serves as a vehicle speed maintenance section to maintain the vehicle's speed based on a signal from the vehicle speed sensor 40. The power storage capacity of the battery 26 can be calculated based on the battery 26's terminal voltage or the electrical power input to and output from the battery 26. This calculation can be performed by the controller 38. The battery 26's temperature can be detected by a temperature sensor 42 located in the battery 26 and can be obtained by the controller 38. Additionally, the controller 38 controls the operation of the radiator fan 36, for example, based on the battery 26's state, the electrical power input / output, or the battery 26's temperature at that time. Simultaneously, the controller 38 serves as a radiator fan operation controller.Based, for example, on a predefined relationship between the charged / discharged electrical power of battery 26 and the airflow of the cooling fan 36, the controller 38 controls the cooling fan 36 so that the airflow corresponds to the charged / discharged electrical power at that time. Furthermore, the controller 38 predefines a relationship between the temperature of battery 26 and the airflow of the cooling fan 36 and controls the cooling fan 36 so that the airflow corresponds to the temperature at that time. In addition to the accelerator pedal and similar devices described above, the driver's request may include an operating mode selector switch 44 for switching between EV and HV operating modes and a regeneration switch 46 for increasing the power storage level of the battery 26 to restore the battery 26 to a fully charged state or a power storage level close to a fully charged state. When the driver operates the operating mode selector switch 44, the operating mode is switched from EV to HV or vice versa in this vehicle 10. Additionally, when the driver operates the regeneration switch 46, each of the main drive motors 14, 16, 18 is controlled to increase the power storage level of the battery 26 so that the power storage level is equal to or close to a full charge.This means that when the recovery switch 46 is actuated and switched to an on state, the operation of each of the main drive motors 14, 16, 18 is controlled so that the battery 26 is charged. The operation of each of the main drive motors 14, 16, 18 and that of the other equipment based on the on state of the recovery switch 46 is described below as a "recovery operation". Charging does not necessarily have to be carried out every time the recovery switch 46 is in the on state. The controller 38 controls the operation of each of the main drive motors 14, 16, 18 so that charging is carried out or a charging opportunity is increased according to the status of the vehicle.For example, charging cannot be performed when the accelerator pedal is no longer pressed, and the charging amount can be increased while the brake pedal is pressed, thus generating a greater regenerative braking force than when the recovery switch 46 is off. The recovery switch 46 is a switch for increasing the power storage amount to issue a command when it is switched to the on state, so that each of the main drive motors 14, 16, 18 increases the power storage amount of the battery 26. Additionally, when the recovery switch 46 is in the on state, it can be determined that the driver requests charging of the battery 26. The control unit 38 controls each of the main drive motors 14, 16, 18, the battery 26, and similar components based on the detected driver request and the detected vehicle status. The vehicle 10 operates using the electrical power stored through external charging when the power storage capacity of the battery 26 is sufficient due to external charging. At this time, the vehicle is essentially powered only by the electric motors. Additionally, once the electrical power stored through external charging is depleted—that is, once the power storage capacity falls below a specified value—the control unit executes such a control process that the required driving force is obtained from the electric motors and the internal combustion engine, and the battery's power storage capacity remains within a specified range.In the event that the battery 26 is fully charged or close to fully charged when the vehicle 10 is started, the vehicle 10 initially operates using only the second electric motor 18. If a situation arises requiring high output, such as high speed (e.g., 100 km / h or higher) or rapid acceleration, the internal combustion engine 14 is started. Similarly, the internal combustion engine 14 may be started due to a demand from a built-in air conditioning system or due to a condition such as the temperature of the battery 26 or the internal combustion engine 14 (e.g., low temperature), or similar factors.When the power storage level is reduced to a specific value, for example 60%, the vehicle is powered either by one of the internal combustion engine 14 and the second electric motor 18, or by both. Which main drive unit is used is determined in advance according to the driver's requirements and the vehicle's status. For example, the internal combustion engine 14 is not used, but the second electric motor 18 is used to power the vehicle during low-speed travel. When the vehicle speed reaches a specified speed or higher, the internal combustion engine 14 is started, and the vehicle is powered by both of them.Additionally, when the power storage amount decreases to the specified value, for example 40%, the first electric lathe 16 is driven to generate electrical power using part of the output of the internal combustion engine 14 and stores the electrical energy in the battery 26. The operating mode can be switched to a driver-requested mode by operating the mode selector switch 44. If the mode selector switch 44 is operated while the vehicle is in HV mode, it can be driven in EV mode, i.e., by only the second electric motor 18. In EV mode, the internal combustion engine 14 is not operated. This reduces noise. If the mode selector switch 44 is operated repeatedly, the vehicle can resume operating in HV mode. Additionally, if the mode selector switch 44 is operated while the vehicle is in EV mode, the vehicle can be switched to HV mode. Driving in HV mode helps to preserve the battery's energy storage capacity 26.If the operating mode switch 44 is repeatedly operated, the operating mode can be resumed in EV mode. The recovery switch 46 is used to request charging of the battery 26. In the "on" state, charging is encouraged and the power storage capacity of the battery 26 is increased. When the recovery switch 46 is actuated to the "on" state, the operation of each of the main drive motors 14, 16, and 18 is controlled, thus increasing the power storage capacity. More precisely, charging is carried out by power generation by the first electric motor 16, by increasing the braking force in regenerative braking, or similar means, to increase the power storage capacity. The controller 38 determines that a charging request is made when the recovery switch 46 is switched to the "on" state and issues a command so that each of the main drive motors 14, 16, and 18 is operated to increase the power storage capacity.In this operation, after the externally charged electrical power is depleted when the recovery switch 46 is actuated, an upper limit for the power storage amount is set higher than a normal upper limit, and charging continues until the power storage amount reaches the modified upper limit. Because the upper limit is set higher, each of the main drive machines 14, 16, 18 is controlled by the upper limit as a setpoint, and is thus controlled so that the power storage amount is increased. For example, it is assumed that the power storage amount is managed to remain within a range of 40 to 60% when the recovery switch 46 is off.When the recovery switch 46 is turned into the on state, the normal upper limit (60%) of the power storage amount is changed to a full charge or a value close to a full charge (for example, 90%). In the event that the recovery switch 46 is activated while the vehicle is operating using externally charged electrical power, a control mechanism is implemented to ensure that the power storage capacity of the battery 26 is not reduced. For example, the vehicle is powered by the drive power of the internal combustion engine 14. To start the internal combustion engine 14, the control unit 38 switches the operating mode to high-voltage (HV) mode. However, if the vehicle is traveling down a long incline, the internal combustion engine 14 is not started; that is, no switch to HV mode occurs. Instead, the power generation capacity of the second electric motor 18 is increased during regenerative braking to restore the power storage capacity. If the driver activates the recovery switch 46 so that it is in the ON state, there is a high probability that the driver is considering subsequent driving in EV mode. That is, if the recovery switch 46 is switched to the ON state, it is predicted that the vehicle would operate in EV mode from that point onward. During EV operation, the electrical power supplied by battery 26 to the second electric motor 18 is expected to increase, thus raising the temperature of battery 26. This temperature increase accelerates battery degradation. Therefore, to mitigate this degradation, it is desirable to suppress the temperature increase. Accordingly, cooling of battery 26 is initiated during the power storage recovery process, thereby reducing its temperature at the start of EV operation. In this way, the temperature of battery 26 during EV operation is reduced compared to a situation where battery 26 is not pre-cooled.For example, in the case where the cooling capacity with respect to battery 26 is insufficient during driving in EV mode, part of the insufficient cooling capacity can be compensated for by cooling in advance. The cooling fan 36 cools the battery 26. When the reset switch 46 is actuated to the ON state and the reset operation is performed, as shown in Fig. 2, the lower operating temperature limit of the cooling fan 36 is changed to a temperature T1 that is lower than the normal temperature T0. For example, a normal setting to stop the cooling fan 36 when the battery 26 temperature is 34°C or lower is changed to a setting to stop the cooling fan 36 when the battery 26 temperature is 30°C or lower. In this way, the operating opportunity of the cooling fan 36 is increased, and thus the battery 26 continues to be cooled. Because the operating opportunity of the cooling fan 36 is increased, the cooling capacity is improved for a relatively long time without changing the airflow of the cooling fan 36 (that is, without immediately improving the cooling capacity).Thus, a control for changing the lower operating temperature limit of the cooling fan in the on-state, so that it is lower than the temperature in the off-state of the recovery switch 46, corresponds to a cooling enhancement control for further cooling of the battery 26. The temperature increase of the battery 26 is suppressed by this cooling enhancement control. Alternatively, the temperature at which the cooling fan 36 starts to operate can be increased so that it is higher than the temperature at which the cooling fan 36 stops (for example, by 2°C), thereby preventing frequent on-off switching. The airflow rate at the time the cooling fan 36 is operating (switched on) can be a fixed value. Additionally, the airflow rate can be a value that is varied according to the charged / discharged electrical power of the battery 26 at that time.Furthermore, the air volume can be a value that is changed according to the temperature of battery 26. Additionally, as shown in Fig. 3, during the recovery operation, the airflow of the cooling fan can be set to an airflow Q1 that is higher than the normal airflow Q0. The normal airflow Q0 is determined based on information other than whether the system is currently in recovery mode (more precisely, the on / off state of the recovery switch 46), for example, information about the charged / discharged electrical power or the temperature of battery 26 at that time. During the recovery operation, the charging opportunity of battery 26 is increased, and the charged electrical power is also increased. In the case where the airflow is changed according to the charged / discharged electrical power, the airflow is increased due to the increase in charged electrical power resulting from the recovery operation.Simultaneously, the controller 38 increases the airflow so that it is greater than the previously stated increase, in order to prepare for the future temperature rise due to the EV operating mode. A similar principle applies to the temperature of battery 26. The charging opportunity is increased by the recovery operation, and the temperature is thereby raised. Simultaneously, the airflow is increased so that it is greater than the airflow increased by the temperature rise, in order to prepare for the future temperature rise due to the EV operating mode. As described, the control to increase the airflow so that it is greater than the airflow determined based on information about the charged / discharged electrical power or the temperature during the on-state of the recovery switch 46 corresponds to the cooling enhancement control for further cooling of battery 26.The airflow rate at the time the cooling fan 36 is operating (is on) can be a fixed value. Additionally, the airflow rate can be a value that changes according to the charged / discharged electrical power of the battery 26 at that time. Furthermore, the airflow rate can be a value that changes according to the temperature of the battery 26. This control for increasing the airflow rate can be implemented in conjunction with the control described above for decreasing the lower operating temperature limit. The airflow of the radiator fan 36 can be varied according to the vehicle speed. A curve Qa, shown in Fig. 4, indicates the airflow of the radiator fan 36 during the recovery operation and also specifies that the airflow increases when the vehicle speed increases. The controller 38 receives the vehicle speed based on an output from the vehicle speed sensor 40 and controls the radiator fan 36 accordingly to deliver the predetermined airflow specified by curve Qa. Because road noise is low at low vehicle speeds, the airflow of the radiator fan 36 is reduced to prevent the noise from being noticeable. Conversely, when the vehicle speed is high and the road noise is loud, the noise of the radiator fan 36 is not noticeable because it is blended with the road noise.Accordingly, the airflow is increased and the cooling capacity is improved. Controlling the airflow in relation to the vehicle speed can involve incremental increases, in addition to continuous increases, as shown in Fig. 4. Furthermore, during power recovery, the airflow can be increased to a level higher than normal. A curve Qb, represented by a dashed line in Fig. 4, indicates the airflow during normal operation. During power recovery, the airflow is increased to prioritize cooling capacity over the noise of the radiator fan 36. Furthermore, the airflow of the radiator fan 36 can be changed based on the vehicle speed and the output of the internal combustion engine. The airflow can be increased when the output of the internal combustion engine 14 is high and the vehicle speed is high. In Fig. 5, curves QAa, QBa, and QCa indicate the characteristics of large, medium, and small airflows, respectively. The controller 38 receives the vehicle speed based on the output of the vehicle speed sensor 40. Additionally, the controller 38 controls the output of the internal combustion engine 14 according to the driver's request and the vehicle's status, receiving the output of the internal combustion engine 14 based on this control instruction. The controller 38 controls the radiator fan 36 in advance to deliver the airflow corresponding to the received vehicle speed and the received output of the internal combustion engine 14. This can be seen in Fig.It can be understood that the air volume increases when the output of the internal combustion engine 14 is increased, provided the vehicle speed remains constant, and that the air volume also increases when the vehicle speed is increased, provided the output of the internal combustion engine remains constant. When the output of the internal combustion engine 14 is increased, the noise produced by the engine is amplified in conjunction with the increase in output. When the output of the internal combustion engine 14 is low, the noise from it is reduced. Accordingly, the air volume is reduced to prevent the noise of the radiator fan 36 from being too prominent. When the output of the internal combustion engine 14 is increased, the noise of the radiator fan 36 is not too prominent, as it blends with the noise of the internal combustion engine 14. Accordingly, the air volume is increased, and the cooling capacity is improved.The airflow can be continuously increased in relation to the machine output and vehicle speed, or it can be increased in stages. Additionally, the control to increase the airflow so that it is greater than during normal operation can be executed during the power storage recovery operation. Curves QAb, QBb, and QCb, represented by dashed lines in Fig. 5, each indicate a characteristic of the airflow during normal operation and, correspondingly, the airflow during recovery operations, which is equal to curves QAa, QBa, and QCa, respectively. During recovery operations, the control to prioritize cooling capacity over the noise of the radiator fan 36 is executed by increasing the airflow. Fig. 6 is a diagram of an example of a processing flow of a subroutine for setting the operation of the radiator fan 36 in the vehicle 10. This flow is executed by the controller 38. The controller 38 determines whether the driver requests charging of the battery 26 (S100). The presence or absence of a charging request can be determined by the on / off state of the recovery switch 46, and it can be determined that the charging request from the driver is present in the on state. If the recovery switch 46 is not in the on state, the normal airflow control, that is, the control for determining the airflow based on information other than the charging request from the driver, is maintained (S102).When the recovery switch 46 is in the ON state, it is determined that a charging request exists, and then it is determined whether the vehicle is operating in HV mode (S104) or EV mode (S106). In the case where the operating mode is neither HV nor EV (for example, during charging via the external power supply), normal airflow control is performed, even if the recovery switch 46 is in the ON state (S102). If step S104 determines that the vehicle is operating in HV mode, the airflow is adjusted based on the vehicle speed and the internal combustion engine output (S108). For example, relevant tabular data, which specifies a corresponding relationship between each of the vehicle speed, the internal combustion engine output, and the airflow, are used, as shown in Fig.As shown in Figure 5, the air volume is stored in advance, and the corresponding air volume is set based on the vehicle speed and the internal combustion engine output at that time. When the air volume is set in step S108, the information used to set the air volume in normal air volume control can be used in addition to the information about the vehicle speed and the internal combustion engine output. If it is determined in step S106 that the vehicle is operating in EV mode, the air volume is set based on the vehicle speed (S110). For example, corresponding table data specifying a relationship between vehicle speed and air volume, as shown in Figure 4, are stored in advance, and the air volume corresponding to the vehicle speed at that time is set.When the airflow is set in step S110, information used to set the airflow in normal airflow control can be used in addition to vehicle speed information. When the airflow is set in step S108 or step S110, the lower operating temperature limit of the radiator fan is set lower than during normal operation (S112). Figure 6 shows that step S112 is performed after steps S108 and S110. However, the order can be reversed. The operation of the radiator fan 36 is controlled based on the modified setting. Fig. 7 is a diagram of another example of the processing flow of the subroutine for setting the operation of the radiator fan 36 in the vehicle 10. This processing is carried out by the controller 38. The controller 38 determines whether the driver requests charging of the battery 26 (S200). The presence or absence of a charging request can be determined by the on / off state of the recovery switch 46, and it can be determined that the charging request from the driver is present in the on state. If the recovery switch 46 is not in the on state, the normal airflow control, that is, the control to determine the airflow based on information other than the charging request from the driver, is maintained (S202).When the recovery switch 46 is in the ON state, it is determined that a charging request exists, and then it is determined whether the internal combustion engine 14 is currently running (S204). If step S204 determines that the internal combustion engine 14 is currently running, the air volume is adjusted based on the vehicle speed and the engine output (S208). This adjustment of the air volume is the same as that described in step S108 above. Conversely, if step S204 determines that the internal combustion engine is currently not running, it is determined whether the vehicle is currently running (S206). In the case where the vehicle is currently not running (for example, while charging via the external power supply), normal air volume control is performed, even if the recovery switch 46 is ON (S202).If the vehicle is currently running in step S206, the airflow is adjusted based on the vehicle speed (S210). This adjustment of the airflow is the same as that described in step S110 above. Additionally, the lower operating temperature limit of the radiator fan is set lower than during normal operation (S212). Figure 7 shows that step S212 is performed after steps S208 and S210. However, the order can be reversed, or step S212 can be performed immediately before step S200. The operation of the radiator fan 36 is controlled based on the modified setting. Fig. 8 is a diagram of another example of the processing flow of the subroutine for setting the operation of the radiator fan 36 in the vehicle 10. This processing is performed by the controller 38. In this processing flow, step S100 in the processing flow shown in Fig. 6 is replaced by step S300. In conjunction with the replacement by step S300, step S302 is modified from step S102. The other steps are the same as those in the processing flow shown in Fig. 6 and are therefore designated by the same reference numerals and are not described. In step S300, the controller 38 predicts whether driving in EV mode will occur in the future. Driving in EV mode can be predicted, for example, based on the state of the recovery switch 46.If the recovery switch 46 is not in the ON state, the normal air volume control, i.e., the control for determining the air volume based on information other than the information about a predicted journey in EV mode, is maintained (S302). If the recovery switch 46 is in the ON state, it is assumed that the driver is currently requesting charging of battery 26 for the future journey in EV mode. Accordingly, the journey in EV mode can be predicted from the time the recovery switch 46 is in the ON state. The control 38 serves as a section for predicting a journey by the electric lathe, which predicts whether the journey in EV mode, i.e., the journey using only the electric lathes, will be undertaken in the future. Additionally, driving in EV mode can be predicted by another method. For example, if a route previously used by the driver is stored, and driving in EV mode occurred within a segment of that route, driving in EV mode can be predicted when driving on the same route again. The control unit 38 can include a route guidance device for guiding the vehicle along a specified route. The control unit 38 stores the driven route and also stores the segment within that route where driving in EV mode occurred. If the previously driven route is searched for, and there is a segment in that route where driving in EV mode occurred, it is predicted that driving in that segment will occur in EV mode. Additionally, driving in EV mode can be predicted according to a time of day. EV mode might be selected early in the morning or late at night. For example, when the vehicle enters a residential area, EV mode might be selected to reduce vehicle noise. Control unit 38 includes a clock and predicts that driving in EV mode will occur in the future when the current time is a specified time of day. This specified time of day can be set by the driver, etc. Fig. 9 is a diagram of another example of the processing sequence of the subroutine for setting the operation of the radiator fan 36 in the vehicle. This processing is carried out by the controller 38. In this processing sequence, step S200 in the processing sequence shown in Fig. 7 is replaced by step S400. In conjunction with the replacement by step S400, step S402 is modified from step S202. The other steps are the same as those in the processing sequence shown in Fig. 7 and are therefore designated by the same reference numerals and are not described. Additionally, steps S400 and S402 are steps in which the same processing is carried out as in steps S300 and S302 in Fig. 8. The preceding description uses the example of the driver being in and operating the vehicle. However, the vehicle user can also be outside the vehicle. For example, a remote operation can be performed. Additionally, in a vehicle performing automatic following (so-called convoy driving), where the vehicle travels by following a vehicle in front, the driver of the vehicle in front becomes a user of the following vehicle and can request battery charging in the following vehicle. The recovery switch 46 can be a switch for which a button, lever, or similar device provided in a passenger compartment, for example, on a dashboard, is used. Additionally, the recovery switch 46 can be a switch indicated on a touch-sensitive display device. Furthermore, the recovery switch 46 can be a switch that is not manually operated but is activated when a specified language is entered. In the automatic following operation described above, the recovery switch 46 can be a switch that is activated by wireless communication from the vehicle ahead. Figure 10 is a diagram illustrating the status of a change in the power storage level of battery 26. During driving in HV mode, the power storage level is managed to remain within the range of 40 to 60%. When a future drive in EV mode is predicted, such as when the recovery switch 46 is turned on (at time t1), the power storage level recovery operation is performed. During the recovery operation, each of the main drive motors 14, 16, and 18 is controlled to promote battery 26 charging, and the power storage level is increased accordingly. When the power storage level reaches 90%, which is a predefined upper limit (at time t2), the power storage level is maintained at this level.When the operating mode switch 44 is actuated (at time t3), the journey begins in EV mode. In EV mode, electrical power is supplied from battery 26 and the amount of stored power is reduced. In the preceding description, the case in which the invention is applied to the plug-in hybrid vehicle was presented as an example. However, the invention can equally be applied to a hybrid vehicle that does not include a charging function from an external power supply (hereinafter described as a general hybrid vehicle). In one configuration of the general hybrid vehicle, for example, the charging port 30 and the charger 34 are located away from the configuration shown in Fig. 1. The general hybrid vehicle is managed such that the battery's charge level remains within a moderate range, for example, the range of 40 to 60%. In the general hybrid vehicle, when the driver can select EV mode, the charge level is increased to exceed the normal range before driving in EV mode. In this way, the driving distance can be extended using EV mode.Similar to the recovery switch 46 described above, an increase switch can be provided to request an increase in the power storage amount. When the driver activates the increase switch, a higher upper limit (for example, 80%) than the upper limit in the normal power storage amount range is set, and each of the main drive motors 14, 16, 18 is controlled according to this setting. Control regarding the setting of the operation of the radiator fan 36 can be carried out, for example, by following the sequences shown in Fig. 7 and Fig. 9. Another example of a preferred aspect of the invention is described below. A control system for a hybrid vehicle comprises: an internal combustion engine and electric motors for propelling the vehicle; a battery that receives electrical power from and transfers it to the electric motors; and a cooling fan for cooling the battery, comprising a cooling fan control section that determines the operation of the cooling fan based on several types of information, including the presence or absence of a charging request based on a user's intention.In the case where the charging request is present due to the user's intention, the cooling fan control section controls the operation of the cooling fan so that the battery is cooled more than in a case where the value of a variable associated with information other than the presence or absence of the charging request by the user's intention is the same, and the charging request by the user's intention is not present.In another aspect, a control system for a hybrid vehicle includes an internal combustion engine and electric motors to propel the vehicle; a battery that receives and transfers electrical power from the electric motors; and a radiator fan to cool the battery; a charge request switch that requests a battery charging operation when it is switched to an on state; and a radiator fan control section that determines an operation of the radiator fan based on several types of information, including an on / off state of the charge request switch.In the case where the charge request switch is in the on state, the radiator fan control section controls the operation of the radiator fan, so that the battery is cooled more than in a case where a value of a variable that is linked to information other than the on / off state of the charge request switch is the same, and the charge request switch is in the off state.In another aspect, a control system for a hybrid vehicle includes an internal combustion engine and electric motors to power the vehicle; a battery that receives and transfers electrical power from the electric motors; and a cooling fan to cool the battery; a section for predicting a drive using only the electric motors, which predicts whether a drive using only the electric motors will occur in the future; and a cooling fan control section that determines the operation of the cooling fan based on information including a prediction of a drive using only the electric motors.In the case where driving is predicted to be done only by the electric lathes, the radiator fan control section controls the operation of the radiator fan so that the battery is cooled more than in a case where the value of a variable associated with information other than the prediction of driving is done only by the electric lathes is the same, and driving is not predicted to be done only by the electric lathes.

Claims

Control system for a hybrid vehicle (10), the control system comprising: an internal combustion engine (14) for powering the vehicle (10); an electric motor (16, 18) for powering the vehicle (10); a battery (26) configured to receive electrical power from and to supply electrical power to the electric motor (16, 18); a radiator fan (36) configured to cool the battery (26);and a controller (38) configured to determine the operation of the cooling fan (36) based on the charged / discharged electrical power of the battery (26) and the presence or absence of a charging request during operation of the hybrid vehicle (10), wherein the charging request is based on a user's intention, wherein the controller (38) is configured to control the operation of the cooling fan (36) such that the battery (26) with the same charged / discharged electrical power is cooled more in a case below i) than in a case below ii), i) the charging request is present, and ii) the charging request is not present. Control system for a hybrid vehicle (10), the control system comprising: an internal combustion engine (14) for powering the vehicle (10); an electric motor (16, 18) for powering the vehicle (10); a battery (26) configured to receive electrical power from and to transfer electrical power to the electric motor (16, 18); a cooling fan (36) configured to cool the battery (26); and a switch (46) configured to issue an instruction for an increase operation of a power storage amount of the battery (26) while the hybrid vehicle (10) is in operation;and a controller (38) configured to determine the operation of the cooling fan (36) based on the charged / discharged electrical power of the battery (26) and the on / off state of the switch (46), wherein the controller (38) is configured to control the operation of the cooling fan (36) such that the battery (26) is cooled with the same charged / discharged electrical power in the following case of i) more than in the case of ii), i) the switch (46) is in the on state, and ii) the switch (46) is in the off state.; Control system for a hybrid vehicle (10), the control system comprising: an internal combustion engine (14) for powering the vehicle (10); an electric motor (16, 18) for powering the vehicle (10); a battery (26) configured to receive electrical power from and to supply electrical power to the electric motor (16, 18); a radiator fan (36) configured to cool the battery (26);and a controller (38) configured to predict whether a drive will be made solely by the electric lathe (16, 18) in a future while the hybrid vehicle (10) is operating, and configured to determine an operation of the radiator fan (36) based on a charged-discharged electrical power of the battery (26) and a prediction of the drive solely by the electric lathe (16, 18), wherein the controller (38) is configured to control the operation of the radiator fan (36) such that the battery (26) is cooled with the same charged-discharged electrical power in a subsequent case of i) more than in a case of ii), i) the drive solely by the electric lathe (16, 18) is predicted, and ii) the drive solely by the electric lathe (16, 18) is not predicted.; Control system according to one of claims 1 to 3, wherein the control (38) is configured to set a lower limit temperature at which the cooling fan (36) is operated lower in the case of i) than in the case of ii). Control system according to one of claims 1 to 3, wherein the control (38) is configured to control an air volume of the cooling fan (36) such that in the case of i) it is greater than in the case of ii). Control system according to claim 4 or 5, wherein the control (38) is configured to maintain a speed of the vehicle (10), and the control (38) is configured to increase an air volume of the radiator fan (36) when a vehicle speed increases, in the case of i). Control system according to one of claims 4 to 6, wherein the control (38) is configured to receive an output from the internal combustion engine (14), and the control (38) is configured to increase the air volume of the cooling fan (36) when the output of the internal combustion engine (14) increases, in the case of i). Control system according to one of claims 4 to 6, wherein the hybrid vehicle (10) is configured to drive by switching between an EV operating mode and an HV operating mode, the EV operating mode being an operating mode in which the vehicle (10) is driven only by the electric motor (16, 18), the HV operating mode being an operating mode in which the vehicle (10) is driven by selectively using either the electric motor (16, 18) or the internal combustion engine (14) according to a given situation, and the control system (38) being configured to increase the air volume of the radiator fan (36) when the output of the internal combustion engine (14) increases, in the case of i) and the vehicle (10) is driving in the HV operating mode.

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