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 a vehicle.

Background Art

[0002] Conventionally, as this type of vehicle, there has been proposed one that includes an engine, a starter, an alternator, and a battery, performs idling stop control for automatically stopping and starting the engine, and periodically performs a refresh charge process on the battery (see, for example, Patent Document 1). In this vehicle, when it is predicted that the period until the next stop timing is less than a predetermined period during the running of the vehicle, the execution of the refresh charge process is prohibited.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a vehicle capable of intermittent engine operation, which includes an engine, a motor generator connected to the engine, a first energy storage device connected to the motor generator via a first power line, a second energy storage device with a lower rated voltage than the first energy storage device and connected to a second power line, and a DC / DC converter capable of stepping down the power from the first power line and supplying it to the second power line, if idling stop control is prioritized over the refresh charging process of the second energy storage device, as described above, the opportunities for the refresh charging process may decrease. To address this, it is conceivable to enable the refresh charging process even when the engine is stopped in order to ensure opportunities for the refresh charging process. During the execution of the refresh charging process, a larger amount of power needs to be supplied from the first power line to the second power line compared to when the refresh charging process is not being performed, in order to charge the second energy storage device, and the decrease in the energy storage ratio of the first energy storage device tends to be larger. Furthermore, when the energy storage ratio of the first energy storage device falls to a certain level, it becomes necessary to start the engine and charge the first energy storage device in order to protect it. Based on the above, it is necessary to ensure a certain amount of engine downtime while the refresh charging process is being performed.

[0005] The primary purpose of the vehicle disclosed herein is to ensure a certain amount of engine downtime when a refresh charging process is initiated while the engine is stopped. [Means for solving the problem]

[0006] The vehicle described herein employs the following means to achieve the primary objectives described above.

[0007] The vehicles disclosed herein are A vehicle comprising an engine, a motor generator connected to the engine, an inverter for driving the motor generator, a first energy storage device connected to the inverter via a first power line, a second energy storage device having a lower rated voltage than the first energy storage device and connected to a second power line, a DC / DC converter capable of stepping down the power from the first power line and supplying it to the second power line, and a control device for controlling the engine, the inverter, and the DC / DC converter, wherein the engine is capable of intermittent operation. The control device starts the engine when the charge level of the first energy storage device falls below the starting threshold while the engine is stopped. The control device, when the waiting time until the next refresh charging process of the second energy storage device using the DC / DC converter is less than a predetermined time, performs at least one of the following: increasing the energy storage rate of the first energy storage device during engine operation compared to when the waiting time is equal to or greater than the predetermined time; or making it less likely to stop the engine during engine operation compared to when the waiting time is equal to or greater than the predetermined time. This is the gist of it.

[0008] In the vehicle of this disclosure, when the waiting time until the next refresh charge processing of the second energy storage device using a DC / DC converter is less than a predetermined time, at least one of the following is performed: the charge storage ratio of the first energy storage device is increased during engine operation compared to when the waiting time is predetermined or longer; or the engine is made less likely to be stopped during engine operation compared to when the waiting time is predetermined or longer. This ensures that when the refresh charge processing is started while the engine is stopped, a certain amount of time is secured for the charge storage ratio of the first energy storage device to fall below the starting threshold, i.e., for the engine to be stopped.

[0009] In the vehicle of this disclosure, the control device controls the engine and the motor during engine operation so that the charge storage ratio approaches the control center, and further, when the standby time is less than a predetermined time, the control center may be raised compared to when the standby time is the predetermined time or longer.

[0010] In the vehicle of this disclosure, the control device may permit the engine to stop when the charge storage ratio is equal to or greater than a stop threshold while the engine is running, and prohibit the engine from stopping when the charge storage ratio is less than the stop threshold. Furthermore, when the waiting time is less than a predetermined time, the stop threshold may be set higher than when the waiting time is equal to or greater than a predetermined time. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic diagram of the vehicle 20 according to the embodiment of the disclosure. [Figure 2] This flowchart shows an example of a processing routine executed by HVECU70. [Figure 3] This flowchart shows an example of a processing routine executed by HVECU70. [Figure 4] This is a schematic diagram of a modified vehicle 120. [Figure 5] This is a schematic diagram of a modified vehicle 220. [Modes for carrying out the invention]

[0012] Embodiments of this disclosure will be described with reference to the drawings. Figure 1 is a schematic diagram of a vehicle 20 according to an embodiment of this disclosure. As shown in the figure, the vehicle 20 of 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, motor ECU 34, and HVECU 70 can communicate with each other via a shared communication line (CAN bus) 90.

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

[0014] The engine ECU 24 is equipped with a microcomputer, which has a CPU, ROM, RAM, flash memory, input / output ports, and communication ports. The engine ECU 24 receives signals from various sensors via its input ports. For example, the engine ECU 24 receives the crank angle θcr from the crank position sensor 23a, which detects the rotational position of the crankshaft 23 of the engine 22, and the coolant temperature from the coolant temperature sensor, which detects the coolant temperature of the engine 22. The engine ECU 24 outputs various control signals via its output ports. For example, the engine ECU 24 outputs control signals to the throttle valve, the fuel injection valve, and the spark plug. The engine ECU 24 calculates the rotational 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 along with a low-voltage battery 60, a DC / DC converter 64, and auxiliary equipment (not shown). A pulley 22a is also 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 with permanent magnets embedded in the rotor core and a stator with three-phase coils wound around the stator core. A pulley 30a is attached to the rotating shaft connected to the rotor of the motor-generator 30. A belt 28 is wrapped around the aforementioned pulleys 22a and 30a. The motor-generator 30 is driven by the switching of multiple switching elements of the inverter 32, enabling power driving and regenerative driving. The inverter 32 is connected to a high-voltage power line 52 along with a high-voltage battery 50 and a DC / DC converter 64.

[0017] The motor ECU 34 is equipped with a microcomputer similar to the engine ECU 24. The motor ECU 34 receives signals from various sensors via input ports. For example, the motor ECU 34 receives the rotational position θm from the rotational position sensor 31a, which detects the rotational position of the rotor of the motor generator 30, and the phase currents Iu, Iv, and Iw from the current sensors 31u, 31v, and 31w, which detect the phase currents of each phase of the motor generator 30. The motor ECU 34 outputs control signals to the inverter 32 via output ports. The motor ECU 34 calculates the electrical angle θe and rotational 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 general 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 the working fluid from the turbine runner to the pump impeller, a one-way clutch that restricts the rotational 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 the torque converter 41, and the output shaft is connected to a drive shaft 46 that is connected to the drive wheels DW via a drive shaft DS and a differential gear DF. The automatic transmission 42 shifts 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] The high-voltage battery 50 is configured as, for example, a lithium-ion battery or a nickel-metal hydride battery, and is connected to the high-voltage power line 52 together with the inverter 32 as described above. The relay 54 is provided on the high-voltage power line 52 and connects and disconnects the inverter 32 side and the high-voltage battery 50 side. The low-voltage battery 60 is configured as, for example, a lead battery whose rated voltage is lower than that of the high-voltage battery 50, and is connected to the low-voltage power line 62 together with the starter 26 and auxiliary equipment as described above.

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

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

[0022] The HVECU70 outputs various control signals via its output ports. For example, the HVECU70 outputs control signals to the starter 26, the power transmission device 40, the relay 54, and the DC / DC converter 64. The HVECU70 calculates the charge level (SOC1) of the high-voltage battery 50 based on the integrated value of the current Ib1 of the high-voltage battery 50 from the current sensor 51b and the voltage Vb1 of the high-voltage battery 50 from the voltage sensor 51a, and calculates the charge level (SOC2) of the low-voltage battery 60 based on the integrated value of the current Ib2 of the low-voltage battery 60 from the current sensor 61b and the 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 the target gear position Gs* of the automatic transmission 42 of the power transmission device 40 based on the accelerator opening Acc and vehicle speed V, and controls the power transmission device 40 so that the gear position Gs of the automatic transmission 42 becomes the target gear position Gs*. The HVECU 70 also sets the required torque Td* required for the input shaft of the automatic transmission 42 based on the accelerator opening Acc, vehicle speed V and the gear position Gs of the automatic transmission 42, and sets the torque command Tm* of the motor generator 30 based on the charge / discharge required power Pb* of the high-voltage battery 50 based on the charge level SOC1 of the high-voltage battery 50. The charge / discharge required power Pb* is set so that the charge level SOC approaches the control center SOC*. Next, the system sets the required torque Te* for the engine 22 based on the requested torque Td* and the torque command Tm* of the motor generator 30, and transmits the required torque Te* to the engine ECU 24 and the torque command Tm* to the motor ECU 34. The engine ECU 24 controls the operation of the engine 22 (such as intake air volume control, fuel injection control, and ignition control) so that the engine 22 is driven based on the required torque Te*. The motor ECU 34 controls the switching of multiple switching elements of the inverter 32 so that the motor generator 30 is driven by the torque command Tm*.

[0024] Furthermore, in the vehicle 20 of the embodiment, idle stop control is performed such that the engine 22 is stopped when a stop condition is met while the engine 22 is running, and the engine 22 is started when a start condition is met thereafter. Examples of stop conditions include AND conditions such as the vehicle being stopped, the brake being applied, the accelerator being released, and the charge level SOC1 of the high-voltage battery 50 being greater than or equal to the stop threshold Ssp. Examples of start conditions include OR conditions such as the brake being released, the accelerator being applied, and the charge level SOC1 of the high-voltage battery 50 falling below the start threshold Sst, which is lower than the stop threshold Ssp.

[0025] Furthermore, in the vehicle 20 of this embodiment, the HVECU 70 periodically performs a refresh charging process for the low-voltage battery 60. During the refresh charging process, the DC / DC converter 64 is controlled so that the low-voltage battery 60 is fully charged.

[0026] Next, the operation of the vehicle 20 of the embodiment will be described. Figure 2 is a flowchart showing an example of a processing routine executed by the HVECU 70. This routine is executed repeatedly at least while the engine 22 is running.

[0027] When this routine is executed, the HVECU70 first determines whether or not the refresh charging process for the low-voltage battery 60 is currently running (step S100). If it determines that the refresh charging process for the low-voltage battery 60 is not currently running, it sets a waiting time Tw until the next refresh charging process for the low-voltage battery 60 (step S110), and then determines whether or not the set waiting time Tw is greater than or equal to the threshold Twref (step S120). Here, the waiting time Tw is set based on, for example, the elapsed time since the end of the previous refresh charging process for the low-voltage battery 60, or the accumulated value of the current Ib2 of the low-voltage battery 60 after the end of the previous refresh charging process for the low-voltage battery 60. The threshold Twref is a threshold used to determine whether or not the waiting time Tw is sufficiently long, and is predetermined.

[0028] If it is determined in step S100 that the refresh charging process for the low-voltage battery 60 is not currently being performed, and if it is determined in step S120 that the waiting time Tw is greater than or equal to the threshold Twrer, then 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 for the low-voltage battery 60 is not currently running, and in step S120 that the waiting time Tw is less than the threshold Twref, or if it is determined in step S100 that the refresh charging process for the low-voltage battery 60 is currently running, then it is determined that the waiting time Tw is relatively short, and a value S2 higher than value S1 is set for the control center SOC* of the high-voltage battery 50 (step S140), and this routine terminates.

[0030] In this way, when the waiting time Tw is less than the threshold Twref, the control center SOC* of the high-voltage battery 50 is increased compared to when the waiting time Tw is greater than or equal to the threshold Twref, thereby increasing the charge level SOC1 of the high-voltage battery 50 when the refresh charging process of the low-voltage battery 60 is started. Now, consider the case when the refresh charging process of the low-voltage battery 60 is started while the engine 22 is stopped by idle stop control. During the execution of the refresh charging process, a larger amount of power needs to be supplied from the high-voltage power line 52 to the low-voltage power line 62 in order to charge the low-voltage battery 60 compared to when the refresh charging process is not being performed, and the decrease in the charge level SOC1 of the high-voltage battery 50 tends to be large. In this embodiment, by keeping the charge level SOC1 of the high-voltage battery 50 high when the refresh charging process is started, the time until the charge level SOC1 of the high-voltage battery 50 falls below the starting threshold Sst can be extended. As a result, it is possible to suppress the starting of the engine 22 due to the condition that the charge level SOC falls below the starting threshold Sst. In other words, it is possible to suppress the shortening of the engine 22's stopping time against the driver's intention while the engine 22 is stopped by the idle stop control.

[0031] In the vehicle 20 of this embodiment described above, the HVECU 70 increases the control center SOC* of the high-voltage battery 50 when the waiting time Tw until the next refresh charging process is less than the threshold Twref, compared to when the waiting time Tw is greater than or equal to the threshold Twref. This makes it possible to lengthen the time it takes for the charge ratio SOC1 of the high-voltage battery 50 to fall below the starting threshold Sst when starting the refresh charging process while the engine 22 is stopped by the idle stop control. As a result, it is possible to suppress the starting of the engine 22 when the condition of the charge ratio SOC falling below the starting threshold Sst is met. In other words, it is possible to suppress the shortening of the engine 22's stopping time against the driver's intention while the engine 22 is stopped by the idle stop control.

[0032] In the embodiment described above, the HVECU70 executed the processing routine shown in Figure 2, but instead, it may execute the processing routine shown in Figure 3. The processing routine in Figure 3 differs from the processing routine in Figure 2 in that the processing in steps S130 and S140 is replaced by the processing in steps S132 and S142. This routine is executed repeatedly at least while the engine 22 is running.

[0033] In the processing routine shown in Figure 3, if the HVECU 70 determines in step S100 that the refresh charging process for the low-voltage battery 60 is not currently running, and in step S120 that the waiting time Tw is greater than or equal to the threshold Twrer, it sets the stop threshold Ssp to the normal value Ssp1 (step S132) and terminates the routine. Also, if the HVECU 70 determines in step S100 that the refresh charging process for the low-voltage battery 60 is not currently running, and in step S120 that the waiting time Tw is less than the threshold Twrer, or if the HVECU 70 determines in step S100 that the refresh charging process for the low-voltage battery 60 is currently running, it sets the stop threshold Ssp to a value higher than the normal value Ssp1, Ssp2 (step S142), and terminates the routine.

[0034] In this way, when the waiting time Tw is less than the threshold Twref, the stop threshold Ssp is set higher compared to when the waiting time Tw is greater than or equal to the threshold Twref, resulting in a relatively high charge ratio SOC1 of the high-voltage battery 50 when the engine 22 is stopped by the idle stop control. Now, consider the case when the refresh charging process is started while the engine 22 is stopped by the idle stop control. As described above, during the execution of the refresh charging process of the low-voltage battery 60, the decrease in the charge ratio SOC1 of the high-voltage battery 50 tends to be larger compared to when the refresh charging process is not being executed. In this modified example, since the charge ratio SOC1 of the high-voltage battery 50 is relatively high when the engine 22 is stopped by the idle stop control, the time it takes for the charge ratio SOC1 of the high-voltage battery 50 to fall below the starting threshold Sst can be extended. As a result, it is possible to suppress the starting of the engine 22 when the condition of the charge ratio SOC falling below the starting threshold Sst is met. In other words, it is possible to suppress the shortening of the engine 22's stopping time against the driver's intention while the engine 22 is stopped by the idle stop control.

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

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

[0037] In the embodiment described above, the engine 22 and the motor generator 30 were connected by a belt mechanism consisting of two pulleys 22a and 30a and a belt 28. However, the engine 22 and the motor generator 30 may also be connected by a chain mechanism, a gear mechanism, or directly connected.

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

[0039] In the embodiment described above, the vehicle 20 is equipped with an engine ECU 24, a motor ECU 34, and an HVECU 70, but at least two of these may be configured as a single unit.

[0040] In the embodiments described above, a vehicle 20 comprising an engine 22, a motor generator 30, an inverter 32, a high-voltage battery 50, a low-voltage battery 60, and a DC / DC converter 64 was described. However, the vehicle is not limited to this, and any vehicle that is capable of intermittent engine operation comprises an engine, a motor generator connected to the engine, an inverter that drives the motor generator, a first energy storage device connected to the inverter via a first power line, a second energy storage device having a lower rated voltage than the first energy storage device and connected to a second power line, and a DC / DC converter capable of stepping down the power from the first power line and supplying it to the second power line. For example, the hardware configurations of the modified vehicles 120 and 220 in Figures 4 and 5 may be used. In the hardware configurations of vehicles 120 and 220 in Figures 4 and 5, the same parts as those in vehicle 20 in Figure 1 are denoted by the same reference numerals, and detailed descriptions are omitted. In vehicle 120 in Figure 4, the motor generator 30 is connected to the engine 22 via a clutch CL, and the power transmission device 40 is connected to the motor generator 30. In the vehicle 220 shown in Figure 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 along with the inverter 32. In addition, an automatic transmission 42 may be provided between the motor generator 230 on the drive shaft 46 and the differential gear DF ​​in the vehicle 220. With this hardware configuration, not only is idle stop control possible, but it is also possible to drive while switching between an electric driving mode in which the vehicle drives with the engine 22 stopped and a hybrid driving mode in which the vehicle drives with the engine 22 running, that is, driving while the engine 22 is running intermittently. Here, one of the conditions for stopping the engine 22 (conditions for transitioning from hybrid driving mode to electric driving mode) is that the charge level SOC1 of the high-voltage battery 50 is equal to or greater than the stop threshold Ssp. Furthermore, one of the conditions for starting the engine 22 (the condition for transitioning from electric driving mode to hybrid driving mode) is when the charge level (SOC1) of the high-voltage battery 50 falls below the starting threshold (Sst).Therefore, not only during idle stop control, but also while driving, the same control as in the above-described embodiment and modified examples can be performed. Specifically, when the waiting time Tw is less than the threshold Twref, the control center SOC* of the high-voltage battery 50 can be increased or the stop threshold Ssp can be increased compared to when the waiting time Tw is greater than or equal to the threshold Twref. This makes it possible to suppress the engine 22 stopping time from being shortened against the driver's intention while the engine 22 is stopped (while driving in electric driving mode).

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

[0042] Furthermore, the correspondence between the main elements of the embodiment and the main elements of the invention described in the section on means for solving the problem is merely an example to specifically explain the form in which the embodiment implements the invention described in the section on means for solving the problem, and does not limit the elements of the invention described in the section on means for solving the problem. In other words, the interpretation of the invention described in the section on means for solving the problem should be based on the description in that section, and the embodiment is merely one specific example of the invention described in the section on means for solving the problem.

[0043] While embodiments for implementing this disclosure have been described above, this disclosure is not limited in any way to these embodiments, and can of course be implemented in various forms without departing from the gist of this disclosure. [Industrial applicability]

[0044] This disclosure can be used in industries such as vehicle manufacturing. [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 Rotation Position Sensor, 31u,31v,31w Current Sensor, 32 Inverter, 34 Motor ECU, 40 Power Transmission, 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 85 Accelerator pedal position sensor, 86 Brake pedal, 87 Brake pedal position sensor, 87 Vehicle speed sensor, 222 Planetary gear, 230 Motor generator, 232 Inverter.

Claims

1. A vehicle comprising an engine, a motor generator connected to the engine, an inverter for driving the motor generator, a first energy storage device connected to the inverter via a first power line, a second energy storage device having a lower rated voltage than the first energy storage device and connected to a second power line, a DC / DC converter capable of stepping down the power from the first power line and supplying it to the second power line, and a control device for controlling the engine, the inverter, and the DC / DC converter, wherein the engine is capable of intermittent operation. The control device starts the engine when the charge level of the first energy storage device falls below the starting threshold while the engine is stopped. The control device performs at least one of the following actions when the waiting time until the next refresh charging process of the second energy storage device using the DC / DC converter is less than a predetermined time: increase the energy storage rate of the first energy storage device during engine operation compared to when the waiting time is equal to or greater than the predetermined time; or make it less likely to stop the engine during engine operation compared to when the waiting time is equal to or greater than the predetermined time. vehicle.

2. The vehicle according to claim 1, The control device controls the engine and the motor during engine operation so that the charge storage ratio approaches the control center, and further raises the control center when the standby time is less than a predetermined time compared to when the standby time is the predetermined time or longer. vehicle.

3. A vehicle according to claim 1 or 2, The control device permits the engine to stop when the charge storage ratio is equal to or greater than the stop threshold during engine operation, and prohibits the engine from stopping when the charge storage ratio is less than the stop threshold. Furthermore, when the waiting time is less than a predetermined time, the control device raises the stop threshold compared to when the waiting time is equal to or greater than the predetermined time. vehicle.

Images