vehicle

Abstract

To secure a certain amount of stop time of an engine when refresh charging processing is started during stop of the engine.SOLUTION: When a power storage ratio of a first power storage device falls below a start threshold during stop of an engine, the engine is started. Additionally, when a standby time until the next refresh charging processing of a second power storage device using a DC / DC converter is less than a prescribed time, at least one of increasing the power storage ratio of the first power storage device during operation of the engine compared to when the standby time is equal to or longer than the prescribed time, and making it less likely to stop the engine during operation of the engine compared to when the standby time is equal to or longer than the prescribed time is executed.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to vehicles. [Background technology]

[0002] Conventionally, this type of vehicle has been proposed to include an engine, starter, alternator, and battery, and to execute idling stop control for automatically stopping and starting the engine, as well as periodically executing refresh charging processing on the battery (see, for example, Patent Document 1). In this vehicle, when the period until the next vehicle stop timing is predicted to be less than a predetermined period while the vehicle is running, execution of the refresh charging processing is prohibited. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-111955 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a vehicle capable of intermittent operation of the engine, the vehicle includes an engine, a motor generator connected to the engine, a first power storage device connected to the motor generator via a first power line, a second power storage device having a lower rated voltage than the first power storage device and connected to the second power line, and a DC / DC converter capable of stepping down the power of the first power line and supplying it to the second power line, and as described above, if the idling stop control is prioritized over the refresh charging process of the second power storage device, there is a possibility that the refresh charging process will be performed less frequently. In response to this, in order to ensure the opportunity for the refresh charging process, it is conceivable to make it possible to perform the refresh charging process even when the engine is stopped. During the refresh charging process, a larger amount of power needs to be supplied from the first power line to the second power line in order to charge the second power storage device than when the refresh charging process is not being performed, and the amount of decrease in the power storage rate of the first power storage device is likely to be large. In addition, when the power storage rate of the first power storage device becomes low to a certain extent, it becomes necessary to start the engine and charge the first power storage device in order to protect the first power storage device. In consideration of the above, it is necessary to ensure a certain amount of time for the engine to be stopped when the refresh charging process is being performed.

[0005] The main objective of the vehicle of the present disclosure is to ensure a certain amount of engine stop time when a refresh charge process is started while the engine is stopped. [Means for solving the problem]

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

[0007] The vehicle of the present disclosure includes: A vehicle capable of intermittent operation of the engine, comprising: an engine; a motor generator connected to the engine; an inverter that drives the motor generator; a first power storage device connected to the inverter via a first power line; a second power storage device having a lower rated voltage than the first power storage device and connected to a second power line; a DC / DC converter that can step down power of the first power line and supply the power to the second power line; and a control device that controls the engine, the inverter, and the DC / DC converter, the control device starts the engine when a power storage ratio of the first power storage device becomes less than a start threshold while the engine is stopped; When a standby time until a next refresh charging process of the second power storage device using the DC / DC converter is less than a predetermined time, the control device executes at least one of: increasing a power storage ratio of the first power storage device while the engine is operating compared to when the standby time is equal to or longer than the predetermined time; and making it more difficult to stop the engine while the engine is operating compared to when the standby time is equal to or longer than the predetermined time. The gist of the present invention is as follows.

[0008] In the vehicle disclosed herein, when the standby time until the next refresh charge process of the second power storage device using the DC / DC converter is less than a predetermined time, at least one of the following is executed: the power storage ratio of the first power storage device is increased while the engine is running compared to when the standby time is equal to or greater than the predetermined time; and the engine is made less likely to be stopped while the engine is running compared to when the standby time is equal to or greater than the predetermined time. This makes it possible to secure a certain amount of time for the power storage ratio of the first power storage device to fall below the start threshold, i.e., the engine stop time, when the refresh charge process is started while the engine is stopped.

[0009] In the vehicle of the present disclosure, the control device may control the engine and the motor while the engine is operating so that the storage ratio approaches a control center, and further, when the standby time is less than a predetermined time, the control center may be made higher than when the standby time is equal to or greater than the predetermined time.

[0010] In the vehicle of the present disclosure, the control device may, during operation of the engine, permit stopping of the engine when the power storage percentage is equal to or greater than a stop threshold, and prohibit stopping of the engine when the power storage percentage is less than the stop threshold, and may further be configured to set the stop threshold higher when the waiting time is less than a predetermined time compared to when the waiting time is equal to or greater than the predetermined time. [Brief description of the drawings]

[0011] [Figure 1] 1 is a schematic configuration diagram of a vehicle 20 according to an embodiment of the present disclosure. [Diagram 2] 13 is a flowchart showing an example of a processing routine executed by the HVECU 70. [Diagram 3] 13 is a flowchart showing an example of a processing routine executed by the HVECU 70. [Figure 4] FIG. 11 is a schematic diagram of a modified vehicle 120. [Diagram 5] FIG. 13 is a schematic diagram of a modified vehicle 220. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] An embodiment of the present disclosure will be described with reference to the drawings. Fig. 1 is a schematic configuration diagram of a vehicle 20 according to an embodiment of the present disclosure. As shown in the figure, the vehicle 20 according to the embodiment includes an engine 22, an engine electronic control unit (hereinafter referred to as "engine ECU") 24, a motor generator 30, an inverter 32, a motor electronic control unit (hereinafter referred to as "motor ECU") 34, a power transmission device 40, a high-voltage battery 50, a relay 54, a low-voltage battery 60, a DC / DC converter 64, and a hybrid electronic control unit (hereinafter referred to as "HVECU") 70. The engine ECU 24, the motor ECU 34, and the HVECU 70 are capable of communicating with each other via a shared communication line (CAN bus) 90.

[0013] The engine 22 is configured as an internal combustion engine that outputs power through four strokes: intake, compression, expansion (explosive combustion), and exhaust, using hydrocarbon fuel such as gasoline or diesel from a fuel tank. The crankshaft 23 of the engine 22 is connected to a torque converter 41 of a power transmission device 40.

[0014] The engine ECU 24 includes a microcomputer, which includes a CPU, a ROM, a RAM, a flash memory, an input / output port, and a communication port. The engine ECU 24 receives signals from various sensors via the input ports. For example, the engine ECU 24 receives a crank angle θcr from a crank position sensor 23a that detects the rotational position of the crankshaft 23 of the engine 22, and a coolant temperature from a water temperature sensor that detects the temperature of the coolant of the engine 22. The engine ECU 24 outputs various control signals via the output ports. For example, the engine ECU 24 outputs a control signal to a throttle valve, a control signal to a fuel injection valve, and a control signal to an ignition plug. The engine ECU 24 calculates the rotation speed Ne of the engine 22 based on the crank angle θcr of the engine 22 from the crank position sensor 23a.

[0015] A starter 26 for cranking the engine 22 is connected to the crankshaft 23 of the engine 22. The starter 26 is connected to a low-voltage power line 62 together with a low-voltage battery 60, a DC / DC converter 64, and auxiliary equipment (not shown). In addition, a pulley 22a is attached to the crankshaft 23 of the engine 22.

[0016] The motor generator 30 is configured as a synchronous generator motor, and has a rotor in which a permanent magnet is embedded in the rotor core, and a stator in which a three-phase coil is wound around the stator core. A pulley 30a is attached to a rotating shaft connected to the rotor of the motor generator 30. A belt 28 is wound around the pulley 22a and the pulley 30a. The motor generator 30 is driven for power running or regenerative running by switching a plurality of switching elements of an inverter 32. The inverter 32 is connected to a high-voltage power line 52 together with a high-voltage battery 50 and a DC / DC converter 64.

[0017] The motor ECU 34 includes a microcomputer similar to the engine ECU 24. The motor ECU 34 receives signals from various sensors via an input port. For example, the motor ECU 34 receives a rotational position θm from a rotational position sensor 31a that detects the rotational position of the rotor of the motor generator 30, and phase currents Iu, Iv, and Iw from current sensors 31u, 31v, and 31w that detect the phase currents of the respective phases of the motor generator 30. The motor ECU 34 outputs a control signal to the inverter 32 via an output port. The motor ECU 34 calculates an electrical angle θe and a rotation speed Nm of the motor generator 30 based on the rotational position θm of the rotor of the motor generator 30 from the rotational position sensor 31a.

[0018] The power transmission device 40 includes a torque converter 41 and an automatic transmission 42. The torque converter 41 is configured as a typical fluid transmission device, and includes a pump impeller connected to the crankshaft 23 of the engine 22, a turbine runner connected to the input shaft of the automatic transmission 42, a stator that rectifies the flow of hydraulic oil from the turbine runner to the pump impeller, a one-way clutch that limits the rotation direction of the stator to one direction, and a hydraulically driven lock-up clutch that connects and disconnects the pump impeller and the turbine runner. The torque converter 41 transmits the power from the engine 22 to the input shaft of the automatic transmission 42 with or without amplifying the torque. The automatic transmission 42 is configured as an automatic transmission with, for example, 4 to 10 speeds, and includes an input shaft, an output shaft, at least one planetary gear mechanism, and a plurality of hydraulically driven friction engagement elements (clutches and brakes). The input shaft is connected to a torque converter 41, and the output shaft is connected to a drive shaft 46 which is connected to driving wheels DW via a drive shaft DS and a differential gear DF. The automatic transmission 42 changes the speed of the power transmitted from the torque converter 41 to the input shaft in multiple stages and transmits it to the output shaft. Note that the automatic transmission may be, for example, a continuously variable transmission (CVT) or a dual clutch transmission.

[0019] High-voltage battery 50 is configured as, for example, a lithium-ion battery or a nickel-metal hydride battery, and as described above, is connected to high-voltage power line 52 together with inverter 32. Relay 54 is provided on high-voltage power line 52, and connects and disconnects inverter 32 side and high-voltage battery 50 side. Low-voltage battery 60 is configured as, for example, a lead battery having a lower rated voltage than high-voltage battery 50, and as described above, is connected to low-voltage power line 62 together with starter 26 and the auxiliaries.

[0020] DC / DC converter 64 is connected to the inverter 32 side of high-voltage power line 52 relative to relay 54 and to low-voltage power line 62. DC / DC converter 64 steps down the power of high-voltage power line 52 and supplies it to low-voltage power line 62, and steps up the power of low-voltage power line 62 and supplies it to high-voltage power line 52.

[0021] The HVECU 70 includes a microcomputer similar to the engine ECU 24. The HVECU 70 receives signals from various sensors via input ports. For example, the HVECU 70 receives a rotation speed Nt1 from a rotation speed sensor that detects the rotation speed of the input shaft (the input side of the torque converter) of the power transmission device 40, a rotation speed Nt2 from a rotation speed sensor that detects the rotation speed of the input shaft of the automatic transmission, and a rotation speed Nt3 from a rotation speed sensor that detects the rotation speed of the output shaft of the automatic transmission. The HVECU 70 also receives a voltage Vb1 from a voltage sensor 51a attached between the terminals of the high-voltage battery 50, a current Ib1 from a current sensor 51b attached to the output terminal of the high-voltage battery 50, a voltage Vb2 from a voltage sensor 61a attached between the terminals of the low-voltage battery 60, and a current Ib2 from a current sensor 61b attached to the output terminal of the low-voltage battery 60. HVECU 70 also receives inputs of high-voltage system voltage VH from a voltage sensor attached to high-voltage system power line 52 and low-voltage system voltage VL from a voltage sensor attached to low-voltage system power line 62. HVECU 70 also receives inputs of a start signal from a start switch 80, a shift position SP from a shift position sensor 82 that detects the operating position of a shift lever 81, an accelerator opening Acc from an accelerator pedal position sensor 84 that detects the amount of depression of an accelerator pedal 83, a brake pedal position BP from a brake pedal position sensor 86 that detects the amount of depression of a brake pedal 85, and a vehicle speed V from a vehicle speed sensor 87.

[0022] The HVECU 70 outputs various control signals via the output port. For example, the HVECU 70 outputs a control signal to the starter 26, a control signal to the power transmission device 40, a control signal to the relay 54, and a control signal to the DC / DC converter 64. The HVECU 70 calculates a power storage rate SOC1 of the high-voltage battery 50 based on an integrated value of the current Ib1 of the high-voltage battery 50 from the current sensor 51b and a voltage Vb1 of the high-voltage battery 50 from the voltage sensor 51a, and calculates a power storage rate SOC2 of the low-voltage battery 60 based on an integrated value of the current Ib2 of the low-voltage battery 60 from the current sensor 61b and a voltage Vb2 of the low-voltage battery 61 from the voltage sensor 61a.

[0023] In the vehicle 20 of the embodiment, the HVECU 70 sets a target gear Gs* of the automatic transmission 42 of the power transmission device 40 based on the accelerator opening Acc and the vehicle speed V, and controls the power transmission device 40 so that the gear Gs of the automatic transmission 42 becomes the target gear Gs*. The HVECU 70 also sets a required torque Td* required for the input shaft of the automatic transmission 42 based on the accelerator opening Acc, the vehicle speed V, and the gear Gs of the automatic transmission 42, and sets a torque command Tm* of the motor generator 30 based on a charge / discharge required power Pb* of the high-voltage battery 50 based on a power storage rate SOC1 of the high-voltage battery 50. The charge / discharge required power Pb* is set so that the power storage rate SOC approaches the control center SOC*. Next, the required torque Te* required for the engine 22 is set based on the required torque Td* and the torque command Tm* of the motor generator 30, and the required torque Te* is transmitted to the engine ECU 24, and the torque command Tm* is transmitted to the motor ECU 34. The engine ECU 24 performs operation control of the engine 22 (intake air amount control, fuel injection control, ignition control, etc.) so that the engine 22 is operated based on the required torque Te*. The motor ECU 34 performs switching control of multiple switching elements of the inverter 32 so that the motor generator 30 is driven by the torque command Tm*.

[0024] In addition, the vehicle 20 of the embodiment executes idling stop control, which stops the engine 22 when a stop condition is satisfied while the engine 22 is in operation, and starts the engine 22 when a start condition is satisfied thereafter. The stop condition is, for example, an AND condition of a condition in which the vehicle is stopped, a condition in which the brake is on, a condition in which the accelerator is off, and a condition in which the power storage percentage SOC1 of the high-voltage battery 50 is equal to or higher than the stop threshold value Ssp. The start condition is, for example, an OR condition of a condition in which the brake is off, a condition in which the accelerator is on, and a condition in which the power storage percentage SOC1 of the high-voltage battery 50 falls below a start threshold value Sst that is lower than the stop threshold value Ssp.

[0025] Furthermore, in the vehicle 20 of the embodiment, the HVECU 70 periodically executes a refresh charge process for the low-voltage battery 60. In the refresh charge process, the HVECU 70 controls the DC / DC converter 64 so that the low-voltage battery 60 is fully charged.

[0026] Next, a description will be given of the operation of the vehicle 20 according to the embodiment. Fig. 2 is a flowchart showing an example of a processing routine executed by the HVECU 70. This routine is repeatedly executed at least while the engine 22 is in operation.

[0027] When this routine is executed, the HVECU 70 first determines whether or not the refresh charge process of the low-voltage battery 60 is being executed (step S100). Then, when it is determined that the refresh charge process of the low-voltage battery 60 is not being executed, the HVECU 70 sets a waiting time Tw until the next refresh charge process of the low-voltage battery 60 (step S110), and determines whether or not the set waiting time Tw is equal to or greater than a threshold value Twref (step S120). Here, the waiting time Tw is set based on, for example, the elapsed time from the end of the previous refresh charge process of the low-voltage battery 60, the integrated value of the current Ib2 of the low-voltage battery 60 after the end of the previous refresh charge process of the low-voltage battery 60, or the like. The threshold value Twref is a threshold value used to determine whether or not the waiting time Tw is relatively long, and is determined in advance.

[0028] If it is determined in step S100 that the refresh charging process of the low-voltage battery 60 is not being performed and if it is determined in step S120 that the waiting time Tw is equal to or greater than the threshold value Twrer, the control center SOC* of the high-voltage battery 50 is set to the normal value S1 (step S130), and this routine is terminated.

[0029] If it is determined in step S100 that the refresh charging process of the low-voltage battery 60 is not being executed and if it is determined in step S120 that the waiting time Tw is less than the threshold value Twref, or if it is determined in step S100 that the refresh charging process of the low-voltage battery 60 is being executed, it is determined that the waiting time Tw is relatively short, and the control center SOC* of the high-voltage battery 50 is set to a value S2 higher than the value S1 (step S140), and this routine is terminated.

[0030] In this way, when the standby time Tw is less than the threshold value Twref, the control center SOC* of the high-voltage battery 50 is made higher than when the standby time Tw is equal to or greater than the threshold value Twref, so that the storage ratio SOC1 of the high-voltage battery 50 can be kept high when the refresh charge process of the low-voltage battery 60 is started. Here, consider the case where the refresh charge process of the low-voltage battery 60 is started while the engine 22 is stopped due to the idling stop control. During the execution of the refresh charge process, a large amount of power needs to be supplied from the high-voltage system power line 52 to the low-voltage system power line 62 in order to charge the low-voltage battery 60 compared to when the refresh charge process is not being executed, and the amount of decrease in the storage ratio SOC1 of the high-voltage battery 50 is likely to be large. In the embodiment, by making the storage ratio SOC1 of the high-voltage battery 50 high when the refresh charge process is started, the time until the storage ratio SOC1 of the high-voltage battery 50 becomes less than the start threshold value Sst can be lengthened. As a result, it is possible to suppress the engine 22 from being started due to the establishment of the condition that the storage ratio SOC becomes less than the start threshold value Sst. That is, while the engine 22 is stopped due to the idling stop control, it is possible to prevent the stop time of the engine 22 from being shortened against the driver's will.

[0031] In the vehicle 20 of the present embodiment described above, when the waiting time Tw until the next refresh charge process is less than the threshold value Twref, the HVECU 70 increases the control center SOC* of the high-voltage battery 50 compared to when the waiting time Tw is equal to or greater than the threshold value Twref. This makes it possible to lengthen the time until the power storage ratio SOC1 of the high-voltage battery 50 becomes less than the start threshold value Sst when the refresh charge process is started while the engine 22 is stopped due to the idling stop control. As a result, it is possible to suppress the engine 22 from being started due to the establishment of the condition that the power storage ratio SOC becomes less than the start threshold value Sst. In other words, it is possible to suppress the stop time of the engine 22 from being shortened against the driver's intention while the engine 22 is stopped due to the idling stop control.

[0032] In the embodiment described above, the HVECU 70 executes the processing routine of Fig. 2, but instead of this, the HVECU 70 may execute the processing routine of Fig. 3. The processing routine of Fig. 3 differs from the processing routine of Fig. 2 in that the processing of steps S130 and S140 is replaced with the processing of steps S132 and S142. This routine is repeatedly executed at least while the engine 22 is operating.

[0033] 3, when the HVECU 70 determines in step S100 that the refresh charging process of the low-voltage battery 60 is not being executed and when the HVECU 70 determines in step S120 that the waiting time Tw is equal to or greater than the threshold value Twrer, the HVECU 70 sets the stop threshold Ssp to a normal value Ssp1 (step S132) and ends this routine. When the HVECU 70 determines in step S100 that the refresh charging process of the low-voltage battery 60 is not being executed and when the HVECU 70 determines in step S120 that the waiting time Tw is less than the threshold value Twrer, or when the HVECU 70 determines in step S100 that the refresh charging process of the low-voltage battery 60 is being executed, the HVECU 70 sets the stop threshold Ssp to a value Ssp2 higher than the normal value Ssp1 (step S142) and ends this routine.

[0034] In this way, when the waiting time Tw is less than the threshold value Twref, the stop threshold value Ssp is set higher than when the waiting time Tw is equal to or greater than the threshold value Twref, so that the storage ratio SOC1 of the high-voltage battery 50 is relatively high when the engine 22 is stopped by the idling stop control. Here, consider the case where the refresh charge process is started while the engine 22 is stopped by the idling stop control. As described above, when the refresh charge process of the low-voltage battery 60 is being executed, the amount of decrease in the storage ratio SOC1 of the high-voltage battery 50 is likely to be large compared to when the refresh charge process is not being executed. In this modified example, since the storage ratio SOC1 of the high-voltage battery 50 is relatively high when the engine 22 is stopped by the idling stop control, the time until the storage ratio SOC1 of the high-voltage battery 50 becomes less than the start threshold value Sst can be lengthened. As a result, it is possible to suppress the engine 22 from being started due to the establishment of the condition that the storage ratio SOC becomes less than the start threshold value Sst. That is, while the engine 22 is stopped due to the idling stop control, it is possible to prevent the stop time of the engine 22 from being shortened against the driver's will.

[0035] In the above-described embodiment, when the standby time Tw is less than the threshold value Twref, the HVECU 70 increases the control center SOC* of the high-voltage battery 50 compared to when the standby time Tw is equal to or greater than the threshold value Twref. In the above-described modified example, when the standby time Tw is less than the threshold value Twref, the HVECU 70 increases the stop threshold Ssp compared to when the standby time Tw is equal to or greater than the threshold value Twref. However, these may be combined. That is, when the standby time Tw is less than the threshold value Twref, the control center SOC* of the high-voltage battery 50 and the stop threshold Ssp may be increased compared to when the standby time Tw is equal to or greater than the threshold value Twref.

[0036] In the above-described embodiment, when the standby time Tw is less than the threshold value Twref, the HVECU 70 sets the control center SOC* of the high-voltage battery 50 higher than when the standby time Tw is equal to or greater than the threshold value Twref. Also, in the above-described modified example, when the standby time Tw is less than the threshold value Twref, the HVECU 70 sets the stop threshold Ssp higher than when the standby time Tw is equal to or greater than the threshold value Twref. However, in addition to at least one of these, the start threshold Sst may be lowered during execution of the refresh charging process compared to when the refresh charging process is not being executed.

[0037] In the above-described embodiment, the engine 22 and the motor generator 30 are connected by a belt mechanism including the two pulleys 22a, 30a and the belt 28. However, the engine 22 and the motor generator 30 may be connected by a chain mechanism, via a gear mechanism, or directly.

[0038] In the above-described embodiment, the high-voltage battery 50 is used as the first power storage device, but a capacitor or the like may be used instead of or in addition to this. Also, the low-voltage battery 60 is used as the second power storage device, but a capacitor or the like may be used instead of or in addition to this.

[0039] In the above-described embodiment, the vehicle 20 includes the engine ECU 24, the motor ECU 34, and the HVECU 70, but at least two of these may be integrated into one unit.

[0040] In the above-described embodiment, the vehicle 20 including the engine 22, the motor generator 30, the inverter 32, the high-voltage battery 50, the low-voltage battery 60, and the DC / DC converter 64 has been described. However, the present invention is not limited to this, and any vehicle including an engine, a motor generator connected to the engine, an inverter for driving the motor generator, a first power storage device connected to the inverter via a first power line, a second power storage device having a lower rated voltage than the first power storage device and connected to the second power line, and a DC / DC converter capable of stepping down the power of the first power line and supplying it to the second power line, and capable of intermittent operation of the engine may be used. For example, the vehicle 120, 220 may have the hardware configuration of the modified example of FIG. 4 or FIG. 5. The same parts of the hardware configuration of the vehicle 120, 220 in FIG. 4 and FIG. 5 as those of the vehicle 20 in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted. In the vehicle 120 in FIG. 4, the motor generator 30 is connected to the engine 22 via the clutch CL, and the power transmission device 40 is connected to the motor generator 30. In the vehicle 220 of FIG. 5, the engine 22 is connected to the carrier of the planetary gear 222, the motor generator 30 is connected to the sun gear, and the drive shaft 46 is connected to the ring gear. The motor generator 230 is connected to the drive shaft 46, and the inverter 232 that drives the motor generator 230 is connected to the high-voltage power line 52 together with the inverter 32 and the like. Note that the vehicle 220 may also be provided with an automatic transmission 42 between the motor generator 230 of the drive shaft 46 and the differential gear DF. In the case of these hardware configurations, in addition to the idling stop control, it is possible to run while switching between an electric driving mode in which the vehicle runs with the engine 22 stopped and a hybrid driving mode in which the vehicle runs with the engine 22 operated, that is, while the engine 22 is intermittently operated. Here, as one of the conditions for stopping the engine 22 (a condition for transitioning from the hybrid driving mode to the electric driving mode), a condition that the charge storage rate SOC1 of the high-voltage battery 50 is equal to or higher than a stop threshold value Ssp is used. Furthermore, as one of the conditions for starting the engine 22 (conditions for transitioning from the electric drive mode to the hybrid drive mode), a condition in which the charge storage percentage SOC1 of the high-voltage battery 50 falls below a start threshold value Sst is used.Therefore, not only during idling stop control but also during driving, it is possible to perform control similar to that of the above-described embodiment and modified example, specifically, when the standby time Tw is less than the threshold value Twref, it is possible to perform control to increase the control center SOC* of the high-voltage battery 50 and to increase the stop threshold value Ssp, compared to when the standby time Tw is equal to or greater than the threshold value Twref. This makes it possible to prevent the stop time of the engine 22 from being shortened against the driver's will while the engine 22 is stopped (while driving in the electric driving mode).

[0041] The relationship between the main elements of the embodiment and the main elements of the invention described in the section on Means for Solving the Problems will be described below. In the embodiment, the engine 22 corresponds to the "engine", the motor generator 30 corresponds to the "motor generator", the inverter 32 corresponds to the "inverter", the high-voltage battery 50 corresponds to the "first power storage device", the low-voltage battery 60 corresponds to the "second power storage device", the DC / DC converter 64 corresponds to the "DC / DC converter", and the engine ECU 24, the motor ECU 34, and the HVECU 70 correspond to the "control device".

[0042] Note that the correspondence between the main elements of the embodiment and the main elements of the invention described in the Means for Solving the Problem column does not limit the elements of the invention described in the Means for Solving the Problem column, since the embodiment is an example for specifically explaining the form for implementing the invention described in the Means for Solving the Problem column. In other words, the interpretation of the invention described in the Means for Solving the Problem column should be made based on the description in that column, and the embodiment is merely a specific example of the invention described in the Means for Solving the Problem column.

[0043] The above describes embodiments for implementing the present disclosure, but the present disclosure is not limited to these embodiments, and it goes without saying that the present disclosure can be implemented in various forms without departing from the gist of the present disclosure. [Industrial Applicability]

[0044] The present disclosure is applicable to the vehicle manufacturing industry and the like. [Explanation of symbols]

[0045] 20,120,220 vehicle, 22 engine, 22a pulley, 23 crankshaft, 23a crank position sensor, 24 engine ECU, 26 starter, 28 belt, 30 motor generator, 30a pulley, 31a rotational position sensor, 31u, 31v, 31w current sensor, 32 inverter, 34 motor ECU, 40 power transmission device, 41 torque converter, 42 automatic transmission, 46 drive shaft, 50 high voltage battery, 51a voltage sensor, 51b current sensor, 52 high voltage power line, 54 relay, 60 low voltage battery, 61a voltage sensor, 61b current sensor, 62 low voltage power line, 64 DC / DC converter, 70 HVECU, 80 start switch, 81 shift lever, 82 shift position sensor, 83 accelerator pedal, 84 Accelerator pedal position sensor, 85 brake pedal, 86 brake pedal position sensor, 87 vehicle speed sensor, 222 planetary gear, 230 motor generator, 232 inverter.

Claims

1. A vehicle capable of intermittent operation of the engine, comprising: an engine; a motor generator connected to the engine; an inverter that drives the motor generator; a first power storage device connected to the inverter via a first power line; a second power storage device having a lower rated voltage than the first power storage device and connected to a second power line; a DC / DC converter that can step down power of the first power line and supply the power to the second power line; and a control device that controls the engine, the inverter, and the DC / DC converter, The control device starts the engine when a power storage ratio of the first power storage device becomes less than a start threshold while the engine is stopped, When a standby time until a next refresh charging process of the second power storage device using the DC / DC converter is less than a predetermined time, the control device executes at least one of: increasing a power storage ratio of the first power storage device while the engine is operating compared to when the standby time is equal to or longer than the predetermined time; and making it more difficult to stop the engine while the engine is operating compared to when the standby time is equal to or longer than the predetermined time. vehicle.

2. 2. The vehicle according to claim 1, the control device controls the engine and the motor during operation of the engine so that the power storage ratio approaches a control center, and further, when the standby time is less than a predetermined time, makes the control center higher than when the standby time is equal to or greater than the predetermined time. vehicle.

3. 3. A vehicle according to claim 1 or 2, the control device permits stopping of the engine when the power storage ratio is equal to or greater than a stop threshold during operation of the engine, and prohibits stopping of the engine when the power storage ratio is less than the stop threshold, and further increases the stop threshold when the standby time is less than a predetermined time compared to when the standby time is equal to or greater than the predetermined time. vehicle.

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