hybrid vehicle

Abstract

A hybrid vehicle includes an engine (10), a rotating electric machine (30), an electric power storage device (70), an electric power generation device (20), a switch (150), and an ECU (200). The switch (150) is a switch operated by a user when the user requests execution or stopping of recovery control. The recovery control is control for increasing the electric power storage amount of the electric power storage device (70) by using the electric power generation device (20). The ECU (200) is configured to select any one of a plurality of control modes including a charge maintenance mode and a charge reduction mode, and to control the hybrid vehicle according to the selected control mode.The ECU (200) is configured to select the charge reduction mode when stopping the recovery control is requested by using the switch (150) during execution of the recovery control.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention

[0001] The invention relates to the control of a hybrid vehicle to which a drive electric motor, an electric power storage device that supplies electric power to the drive electric motor, and a machine operated to charge the electric power storage device are mounted. 2. Description of the state of the art

[0002] JP 2011-093 335 A discloses a hybrid vehicle in which, compared to a case where no charging request from a user for increasing the electric power storage size of the electric power storage device is detected, the output power of the engine is increased when the charging request is detected, so that the charging of the electric power storage device is promoted.

[0003] DE 10 2007 056 723 A1 discloses a hybrid vehicle having a powertrain with an engine and at least one electric motor. A method for maximizing the range capability of the vehicle while operating in an electric vehicle operating state includes determining an incipient electric vehicle operating state of the powertrain, setting a preferred charge / discharge rate of an electrical energy storage device to a maximum charge rate, and controlling the powertrain to an operating state including an engine state that is ON to effect charging of the electrical energy storage device based on the maximum charge rate.

[0004] US 2009 / 0 287 366 A1 discloses a hybrid vehicle in which an electric operating mode can be selected by the user. In the electric operating mode, the vehicle is powered solely by an electric motor, with permissible vehicle acceleration limited to below a predetermined acceleration value, preventing engine start during operation in the electric operating mode. SUMMARY OF THE INVENTION

[0005] When the electric power storage device is being charged by operating the engine in response to the user's charging request, the user can request to stop charging the electric power storage device with the intention of limiting the operation of the engine being operated. Stopping charging of the electric power storage device is requested by the user operating a predetermined operating device (operating device) such as a switch.

[0006] However, even if the charging of the electric power storage device is stopped, the limitation of the operation of the machine intended by the user may not be carried out in some cases if the operation of the machine continues according to the state of the vehicle.

[0007] It is an object of the invention to provide a hybrid vehicle that limits the operation of the driven engine to correspond to a user's intention when requesting to stop charging of an electric power storage device using the engine.

[0008] This object is achieved by a hybrid vehicle as defined in claim 1. Advantageous embodiments are the subject of the dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Features, advantages, and technical and industrial significance of exemplary embodiments of the invention are described below with reference to the accompanying drawings, in which like reference numerals designate like elements. In the drawings: Fig. 1 a complete block diagram of a vehicle, Fig. 2 is a diagram illustrating an example of how the SOC (state of charge) changes during execution of SOC (state of charge) recovery control, Fig. 3 a functional block diagram of an ECU, Fig. 4 is a flowchart illustrating control processing executed by the ECU, and Fig. 5 is a timing diagram illustrating the operation of the ECU. DETAILED DESCRIPTION OF EMBODIMENTS

[0010] An embodiment of the invention is described below with reference to the accompanying drawings. In the following description, like reference numerals are used to refer to like parts that share the same names and functions. A detailed description thereof will not be repeated.

[0011] Fig. 1 shows an overall block diagram illustrating a hybrid vehicle 1 (hereinafter referred to simply as "vehicle 1") according to this embodiment. The vehicle 1 includes a transmission 8, an engine (internal combustion engine) 10, a drive shaft 17, a power control unit (PCU) 60, a battery 70, drive wheels 72, a charger 78, an SOC (state of charge) recovery switch 150, an accelerator pedal 160, and an electronic control unit (ECU) 200.

[0012] The transmission 8 includes an output shaft 16, a first motor generator (hereinafter referred to as “first MG”) 20, a second motor generator (hereinafter referred to as “second MG”) 30, a power split device 40, and a deceleration device 58.

[0013] The ECU 200 receives various signals from various sensors such as a vehicle wheel speed sensor 14, a current sensor 152, a voltage sensor 154, a battery temperature sensor 156, and a pedal stroke sensor 162.

[0014] The vehicle 1 with the above-described configuration travels by using the driving force output from the engine 10 and / or the second MG 30. The power generated by the engine 10 is split into two paths by the power split device 40. One of the two paths is a path through which the power is transmitted to the drive wheels 72 via the deceleration device 58, and the other path is a path through which the power is transmitted to the first MG 20.

[0015] For example, the first MG 20 and the second MG 30 are three-phase rotating electrical machines. The first MG 20 and the second MG 30 are driven by the PCU 60.

[0016] The first MG 20 functions as a generator (electric power generation device) that generates electric power by using the power of the engine 10 split by the power split device 40 and charges the battery 70 by the PCU 60. In addition, the first MG 20 rotates a crankshaft, which is an output shaft of the engine 10, by receiving electric power from the battery 70. Thus, the first MG 20 functions as a starter that starts the engine 10.

[0017] The second MG 30 functions as a drive motor that supplies driving force to the drive wheels 72 using the electric power stored in the battery 70 and / or the electric power generated by the first MG 20. Additionally, the second MG 30 functions as a generator for charging the battery 70 through the PCU 60 using the electric power generated by regenerative braking.

[0018] The engine 10, which is a gasoline engine (a gasoline engine) having a plurality of cylinders (4 cylinders according to this embodiment) 112, is controlled based on a control signal S1 from the ECU 200. The construction of the engine 10 is not specifically limited to that shown in Fig. 1 is illustrated.

[0019] In the engine 10 having the above-described configuration, the ECU 200 controls a fuel injection amount for each of the cylinders 112 by injecting an appropriate amount of fuel into each of the cylinders 112 and stopping the fuel injection into the cylinders 112 at an appropriate time.

[0020] The power split device 40 is configured to split the power generated by the engine 10 between the path leading to the drive shaft 17 through the output shaft 16 and the path leading to the first MG 20. A planetary gear mechanism including three rotating shafts of a sun gear, a planetary carrier, and a ring gear can be used as the power split device 40. For example, the engine 10, the first MG 20, and the second MG 30 can be mechanically connected to the power split device 40 by connecting a rotor of the first MG 20 to the sun gear, connecting the output shaft of the engine 10 to the planetary carrier, and connecting the output shaft 16 to the ring gear.

[0021] The output shaft 16, which is also connected to a rotor of the second MG 30, is mechanically connected via the deceleration device 58 to the drive shaft 17, which drives the drive wheels 72 to rotate. A gear box may also be installed between a rotating shaft of the second MG 30 and the output shaft 16.

[0022] The PCU 60 converts the DC electric power supplied from the battery 70 into AC electric power and drives the first MG 20 and the second MG 30. In addition, the PCU 60 converts the AC electric power generated by the first MG 20 and the second MG 30 into DC electric power and charges the battery 70. For example, the PCU 60 is configured to include an inverter (not shown) for DC / AC electric power conversion and a converter (not shown) for performing DC-DC conversion between a DC connection side of the inverter and the battery 70.

[0023] The battery 70, which is an electric power storage device, is a rechargeable direct current electric power supply. For example, a secondary battery such as a nickel-hydrogen battery and a lithium-ion battery is used as the battery 70. The voltage of the battery 70 is, for example, approximately 200 V. The battery 70 can be charged not only by using the electric power generated by the first MG 20 and / or the second MG 30 as described above, but also by using the electric power supplied from an external electric power supply 302 (described below). The battery 70 is not limited to the secondary battery and can be a device capable of generating direct current, examples of which include a capacitor, a solar cell, and a fuel cell.

[0024] Current sensor 152, voltage sensor 154, and battery temperature sensor 156 are arranged in battery 70. Current sensor 152 detects current IB of battery 70 and sends a signal indicating the detection result to ECU 200. Voltage sensor 154 detects voltage VB of battery 70 and sends a signal indicating the detection result to ECU 200. Battery temperature sensor 156 detects battery temperature TB of battery 70 and sends a signal indicating the detection result to ECU 200.

[0025] The ECU 200 estimates the electric power storage amount (hereinafter referred to as "state of charge (SOC)") of the battery 70 based on the current IB, the voltage VB, and the battery temperature TB of the battery 70. For example, the ECU 200 may estimate an open circuit voltage (OCV) based on the current, voltage, and battery temperature, and may estimate the SOC of the battery 70 based on the estimated OCV and a predetermined map. Alternatively, for example, the ECU 200 may estimate the SOC of the battery 70 by integrating the charging current and the discharging current of the battery 70 with each other.

[0026] While the vehicle 1 is stopped, the charging device 78 charges the battery 70 with the electric power supplied from the external electric power supply 302 by attaching a charging plug 300 to the vehicle 1. The charging plug 300 is connected to one end of a charging cable 304. The other end of the charging cable 304 is connected to the external electric power supply 302. A positive electrode terminal of the charging device 78 is connected to an electric power supply line PL that connects a positive electrode terminal of the PCU 60 and a positive electrode terminal of the battery 70. A negative electrode terminal of the charging device 78 is connected to a ground line NL that connects a negative electrode terminal of the PCU 60 and a negative electrode terminal of the battery 70.A charging method of supplying electric power from the external electric power supply 302 to the battery 70 of the vehicle 1 by a non-contact electric power supply such as a resonance technique and electromagnetic induction may be used in addition to or instead of the charging method in which electric power is supplied from the external electric power supply 302 to the battery 70 of the vehicle 1 by the contact electric power supply using the charging plug 300 or the like.

[0027] The vehicle wheel speed sensor 14 detects the rotational speed Nw of the drive wheels 72. The vehicle wheel speed sensor 14 sends a signal indicative of the detected rotational speed Nw to the ECU 200. The ECU 200 calculates a vehicle speed V based on the received rotational speed Nw. The ECU 200 may calculate the vehicle speed V based on the rotational speed of the second MG 30 instead of the rotational speed Nw.

[0028] The accelerator pedal 160 is arranged on a driver's seat. The pedal stroke sensor 162 is arranged on or in the accelerator pedal 160. The pedal stroke sensor 162 detects the stroke amount (operation amount) AP of the accelerator pedal 160. The pedal stroke sensor 162 sends a signal indicating the stroke amount AP to the ECU 200. An accelerator pedal operation force sensor for detecting an operation force of an occupant in the vehicle 1 with respect to the accelerator pedal 160 can be used instead of the pedal stroke sensor 162.

[0029] The ECU 200 generates the control signal S1 for controlling the engine 10 and outputs the generated control signal S1 to the engine 10. In addition, the ECU 200 generates a control signal S2 for controlling the PCU 60 and outputs the generated control signal S2 to the PCU 60.

[0030] The ECU 200 is a control device that controls the charge and discharge state of the entire hybrid system, that is, the battery 70, and the operating states of the engine 10, the first MG 20, and the second MG 30 such that, when controlling the engine 10, the PCU 60, and the like, the vehicle 1 is operated at the maximum efficiency.

[0031] The ECU 200 calculates a vehicle power request according to the stroke amount AP of the accelerator pedal 160 arranged on the driver's seat and the vehicle speed V. The ECU 200 controls the torque of the first MG 20, the torque of the second MG 30, or the output power of the engine 10 according to the calculated vehicle power request.

[0032] According to this embodiment, the ECU 200 controls the PCU 60 and the engine 10 in any of the control modes including a mode (hereinafter referred to as a charge depleting (CD) mode) in which traveling is performed by consuming the electric power of the battery 70 while allowing the SOC to decrease (with the SOC not being maintained), and a mode (hereinafter referred to as a charge sustaining (CS) mode) in which the engine 10 is operated or stopped and traveling is performed with suppression of the SOC to decrease of the battery 70 (including a case where the SOC is maintained).

[0033] The CD mode is not specifically limited to non-maintenance of the SOC. For example, the CD mode may be a mode that prefers driving in which the electric power of the battery 70 is consumed by electric vehicle (EV) driving to driving based on maintaining the SOC of the battery 70. In addition, the control modes may include a control mode other than the CD mode and the CS mode. The use of the control modes is not limited to controlling the vehicle 1 while driving. The control modes are also used to control the vehicle 1 when the vehicle 1 is traveling and when the vehicle 1 is stopped.

[0034] For example, the ECU 200 performs automatic switching between the CD mode and the CS mode. For example, the ECU 200 controls the PCU 60 and the engine 10 in the CD mode when the SOC of the battery 70 exceeds a switching threshold A, and controls the PCU 60 and the engine 10 in the CS mode when the SOC of the battery 70 is less than the switching threshold A. The ECU 200 can perform switching between the CD mode and the CS mode in response to a user's operation of an operation part (operating part), such as a switch and a lever, arranged to switch the control mode.

[0035] When the vehicle 1 is traveling in the CD mode, the operation of the electric power generation engine 10 is suppressed (that is, a decrease in the SOC of the battery 70 is permitted). Accordingly, the SOC of the battery 70 is not maintained, the electric power of the battery 70 is consumed in response to an increase in traveling distance, and the SOC of the battery 70 decreases.

[0036] In the CD mode, the ECU 200 controls the PCU 60 such that the vehicle 1 runs only by using the output power of the second MG 30 to the extent that the vehicle power request does not exceed a start threshold value Pr(1) of the engine 10.

[0037] In a case where the vehicle 1 travels only by the output of the second MG 30 in the CD mode, the ECU 200 starts the engine 10 after the vehicle power demand exceeds the start threshold Pr(1) of the engine 10 (that is, after determining that it is impossible to satisfy the vehicle power demand with the output of the second MG 30 alone), and controls the PCU 60 and the engine 10 so that the vehicle power demand is satisfied by using the output of the second MG 30 and the output of the engine 10. In other words, the CD mode is a control mode in which the operation of the engine 10 to satisfy the vehicle power demand can be performed while the operation of the engine 10 for electric power generation is suppressed.Furthermore, the engine 10 can be started in a case where the actual power of the vehicle 1, not the vehicle power demand, exceeds the start threshold of the engine 10. In addition, the ECU 200 stops the engine 10 in a case where the vehicle power demand is exceeded by a stop threshold of the engine 10 in the CD mode. The stop threshold in the CD mode, which is a predetermined value, is equal to or less than the start threshold Pr(1).

[0038] During travel of the vehicle 1 in the CS mode, the operation of the electric power generation engine 10 is permitted, and a decrease in the SOC of the battery 70 is suppressed by maintaining the SOC of the battery 70 or restoring the SOC of the battery 70.

[0039] For example, the ECU 200 may perform charge and discharge control for the battery 70 such that the SOC of the battery 70 in the CS mode is within a predetermined control range (for example, within a control range including the switching threshold A described above), or may perform charge and discharge control for the battery 70 such that the SOC of the battery 70 maintains a predetermined target SOC (for example, the switching threshold A described above).

[0040] Examples of the charging control of the battery 70 include charging control using the regenerative electric power generated by the regenerative braking of the second MG 30 and charging control using the electric power generated by the first MG 20 by using the power of the engine 10.

[0041] In a case where the SOC of the battery 70 significantly exceeds a predetermined control range and a predetermined target SOC in the CS mode, the ECU 200 controls the PCU 60 such that the vehicle travels by using only the output power of the second MG 30 to the extent that the vehicle power request does not exceed a start threshold Pr(2) of the engine 10.

[0042] In a case where the vehicle 1 travels by using only the output of the second MG 30 in the CS mode, as described above, the ECU 200 starts the engine 10 after the vehicle power demand exceeds the start threshold Pr(2) of the engine 10 (that is, after determining that it is impossible to satisfy the vehicle power demand with the output of the second MG 30 alone), and controls the PCU 60 and the engine 10 so that the vehicle power demand is satisfied by using the output of the second MG 30 and the output of the engine 10. In other words, the CS mode is a control mode in which both the electric power generation operation of the engine 10 and the vehicle power demand satisfaction operation of the engine 10 can be performed.In addition, the ECU 200 stops the engine 10 in a case where the power demand exceeds the stop threshold of the engine 10 in the CS mode. The stop threshold in the CS mode, which is a predetermined value, is equal to or less than the start threshold Pr(2).

[0043] According to this embodiment, the start threshold Pr(1) in the CD mode is higher than the start threshold Pr(2) in the CS mode, and the stop threshold in the CD mode is higher than the stop threshold in the CS mode. Each of the start thresholds Pr(1) and Pr(2) is a value equal to or less than the upper limit value of the output power of the second MG 30 and equal to or less than the upper limit value (Wout) of the output power of the battery 70. In this case, a difference occurs between the chances of running the engine 10 in the CD mode and the CS mode.

[0044] In addition, the ECU 200 executes SOC (state of charge) recovery control to increase the SOC of the battery 70 to a predetermined target by operating the engine 10 when receiving an SOC recovery switch operation signal from the SOC recovery switch 150. The SOC recovery control is control executed when a CHG mode, which is different from the CD mode and the CS mode, is selected. The CHG mode differs from the CS mode in that a control target for the SOC is a full charge threshold C, and the SOC is increased to the full charge threshold C.

[0045] The SOC recovery switch 150 is a switch used when the user requests the execution or stop of the SOC recovery control. The CHG mode is selected when the user operates the SOC recovery switch 150 (hereinafter, this operation is referred to as the ON operation) while a control mode other than the CHG mode is selected. Then, the execution of the SOC control is requested. Accordingly, the SOC value can be increased in advance contrary to the selection of the CD mode. In this way, the selection of the CD mode can continue for a certain period of time. A stop of the SOC recovery control is requested when the user operates the SOC recovery switch 150 (hereinafter, this operation is referred to as the OFF operation) while the CHG mode is selected.

[0046] The following is an example of how the SOC changes during the execution of the SOC recovery control (that is, while the CHG mode is selected), with reference to Fig. 2. As an example, assume a case where driving of the vehicle 1 in the CD mode is initiated in a case where the battery 70 is in a fully charged state (a state where the SOC of the battery 70 has reached the full charge threshold C), as shown in Fig. 2. The full charge threshold C is, for example, the upper limit of the SOC of the battery 70, which is set in a case where the battery 70 is charged by using the external electric power supply 302.

[0047] In the case of driving in CD mode, since, for example, the frequency of EV driving is higher than the frequency of hybrid vehicle (HV) driving, the electric power of the battery 70 is consumed. Accordingly, the SOC of the battery 70 decreases over time.

[0048] In a case where the SOC recovery switch 150 is not operated until the SOC of the battery 70 reaches the switching threshold A at the time T(0), the control mode is switched from the CD mode to the CS mode at the time when the switching threshold A is reached, as shown by the dashed line in the graph in the middle of Fig. 2. Then, the SOC of the battery 70 is controlled with the switching threshold A as a target value, and thus the SOC of the battery 70 fluctuates with the threshold A being the center of the control, as shown by the dashed line in the upper graph of Fig. 2 is illustrated.

[0049] In a case where the ON operation is performed on the SOC recovery switch 150 and an ON state occurs at time T(0), for example, the control mode is switched from the CD mode to the CHG mode. When the CHG mode is selected, the SOC of the battery 70 is controlled with the full charge threshold C, which is the upper limit of the SOC of the battery 70, as the target value. Accordingly, the SOC of the battery 70 increases over time due to, for example, electric power generation using the power of the engine 10, as shown by the solid line in the upper graph in Fig. 2. The SOC recovery control continues until at least the SOC of the battery 70 reaches the full charge state C at time T(1).

[0050] During the execution of the SOC recovery control in the hybrid vehicle having the above-described configuration, the user can request the stop of the SOC recovery control by performing the OFF operation on the SOC recovery switch 150 with the intention of limiting the operation of the operated engine 10.

[0051] However, even if the SOC recovery control is stopped, the operation of the engine 10 may continue according to the state of the vehicle 1, for example, if the CS mode is subsequently selected. Accordingly, in some cases, the limitation of the operation of the engine 10 intended by the user may not be executed.

[0052] The ECU 200 according to this embodiment is characterized in that in a case where a stop of the SOC recovery control is requested by using the SOC recovery switch 150 during the execution of the SOC recovery control, the CD mode is selected.

[0053] In this case, since the CD mode, in which the start threshold of the engine 10 is higher than in the CS mode with respect to the vehicle power demand and the electric power of the battery 70 is consumed, is selected in a case where the SOC recovery control is requested to stop using the SOC recovery switch 150 during the execution of the SOC recovery control, charging of the battery 70 using the power of the engine 10 is suppressed. Accordingly, the operation of the engine 10 can be more limited than in a case where the CS mode is selected.

[0054] In addition, according to this embodiment, the ECU 200 selects the CS mode in a case where the execution of the SOC recovery control causes the SOC of the battery 70 to reach the full charge threshold C.

[0055] Fig. 3 shows a functional block diagram of the ECU 200 mounted on the vehicle 1 according to this embodiment. The ECU 200 includes a CHG mode determination unit 202, an OFF operation determination unit 204, a termination determination unit 206, and a CD / CS mode selection unit 208. These components can be implemented by software such as a program or by hardware.

[0056] The CHG mode determination unit 202 determines whether the CHG mode is selected or not. The CHG mode determination unit 202 determines whether the CHG mode is selected based on, for example, the state of a mode flag that is in an ON state when the CHG mode is selected. The CHG mode determination unit 202 determines that the CHG mode is selected in a case where, for example, the mode flag is in the ON state. The ON state of the mode flag occurs when, for example, the ON operation is performed on the SOC recovery switch 150. An OFF state of the mode flag occurs when, for example, the OFF operation is performed.

[0057] The OFF operation determination unit 204 determines whether the OFF operation has been performed based on the SOC recovery switch operation signal received from the SOC recovery switch 150. The OFF operation determination unit 204 determines that the OFF operation has been performed in a case where the SOC recovery switch operation signal is received from the SOC recovery switch 150 while the CHG mode is selected.

[0058] The completion determination unit 206 determines whether or not the charging of the battery 70 is completed based on the SOC recovery control. Specifically, in a case where the SOC of the battery 70 reaches the full charge threshold C during the execution of the SOC recovery control, the completion determination unit 206 determines that the charging of the battery is completed based on the SOC recovery control.

[0059] The CD / CS mode selection unit 208 selects a control mode based on the determination result of the CHG mode determination unit 202, the determination result of the OFF operation determination unit 204, and the determination result of the completion determination unit 206. Specifically, the CD / CS mode selection unit 208 selects the CD mode as the control mode in a case where it is determined by the CHG mode determination unit 202 that the CHG mode is selected and it is determined by the OFF operation determination unit 204 that the OFF operation has been performed on the SOC recovery switch 150.In the case of determining that the CHG mode is selected, the CD / CS mode selection unit 208 selects the CS mode as the control mode until it is determined by the completion determination unit 206 that the SOC recovery control is completed, in a case where it is not determined by the OFF operation determination unit 204 that the OFF operation has been performed on the SOC recovery switch.

[0060] A control processing executed by the ECU 200 mounted on the vehicle 1 according to this embodiment will be described with reference to Fig. 4 described.

[0061] In step 100 (hereinafter, step 5 is referred to as "S"), the ECU 200 determines whether the CHG mode is selected or not. If it is determined that the CHG mode is selected (YES in S100), the processing proceeds to S102. Otherwise (NO in S100), this processing is terminated.

[0062] In S102, the ECU 200 determines whether the OFF operation has been performed on the SOC recovery switch 150. If it is determined that the OFF operation has been performed on the SOC recovery switch 150 (YES in S102), the processing proceeds to S104. Otherwise (NO in S102), the processing proceeds to S106.

[0063] In S104, the ECU 200 selects the CD mode as the control mode. In S106, the ECU 200 determines whether or not charging of the battery 70 based on the SOC recovery control is completed. If it is determined that charging of the battery 70 based on the SOC recovery control is completed (YES in S106), the processing proceeds to S108. Otherwise (NO in S106), the processing is terminated. In S108, the ECU 200 selects the CS mode as the control mode.

[0064] The operation of the ECU 200 mounted on the vehicle 1 according to this embodiment will be described with reference to Fig. 5 and based on the structure and flowchart described above.

[0065] As an example, assume a case where the vehicle 1 is operated in a state in which the CHG mode is selected, as shown in Fig. 5. The engine 10 is in an operating state (ON state) because the SOC recovery control is being executed.

[0066] Until time T(2), the OFF operation of the SOC recovery switch 150 is not performed (NO in S102), and the CHG mode is selected (YES in S100). Accordingly, the CHG mode is maintained.

[0067] In a case where, at time T(2), the OFF operation is performed on the SOC recovery switch 150 (YES in S102) while the CHG mode is selected (YES in S100), the CD mode is selected as the control mode (S104), as shown by the solid line in the upper graph in Fig. 5. The selection of the CD mode causes the operation of the engine 10 to be determined by the starting threshold with respect to the vehicle power demand corresponding to the CD mode. As a result, the engine 10 is stopped at time T(2), as indicated by the solid line in the graph in the middle of Fig. 5 is illustrated.

[0068] Stopping the SOC recovery control causes the charging of the battery 70 to stop. In addition, since the selection of the CD mode causes consumption of the electric power of the battery 70, the SOC is reduced with the passage of time after time T(2), as shown by the solid line in the graph at the bottom of Fig. 5 is illustrated.

[0069] In a case where the OFF operation on the SOC recovery switch 150 is not performed at time T(2) (NO in S102) while the CHG mode is selected (YES in S100), the selection of the CHG mode is maintained even after time T(2). Accordingly, the SOC of the battery 70 increases over time based on the SOC recovery control, as shown by the dashed line in the graph in the lower part of Fig. 5 is illustrated.

[0070] In a case where at time T(3) the charging of the battery 70 based on the SOC recovery control is completed (YES in S106), the CS mode is selected as the control mode (S108) as shown by the dashed line in the upper graph in Fig. 5. The selection of the CS mode causes the SOC of the battery 70 to be maintained after time T(3), and the operation of the engine 10 is determined by the start threshold of the engine 10 with respect to the vehicle power demand, which corresponds to the CS mode. As a result, the operating state of the engine 10 continues after time T(2), as indicated by the dashed line in the graph in the middle of Fig. 5 is illustrated.

[0071] As described above, in the vehicle according to this embodiment, the CD mode in which the electric power of the battery 70 is consumed is selected in a case where the stop of the SOC recovery control is requested by using the SOC recovery switch 150 during the execution of the SOC recovery control, and therefore, the charging of the battery 70 using the power of the engine 10 is suppressed. Accordingly, the operation of the engine 10 can be more restricted (for example, the operation of the engine 10 is stopped and the state in which the operation of the engine is stopped is maintained) than in a case where the CS mode is selected. In other words, the operation of the engine 10 can be restricted to suit the user's intention.Accordingly, it is possible to provide a hybrid vehicle that, in a case where stopping the charging of the electric power storage device using the engine is requested, limits the operation of the operated engine to meet the user's intention.

[0072] In addition, since the CS mode is selected when the SOC of the battery 70 reaches the full charge threshold C during the execution of the SOC recovery control, the SOC of the battery 70 can be maintained near the upper limit. Accordingly, the electric power of the battery 70 can be used for driving the vehicle 1, operating electrical devices connected to the battery 70 and located in a passenger compartment or outside the vehicle, or the like at a timing desired by the user.

[0073] A modification example will be described below. In the description according to this embodiment, the CS mode is selected in a case where the SOC of the battery 70 reaches the full charge threshold C as a result of the execution of the SOC recovery control. However, the invention is not specifically limited to this. For example, the ECU 200 may select the CS mode in a case where the OFF operation is performed on the SOC recovery switch 150 after the battery 70 reaches the full charge state C as a result of the execution of the SOC recovery control.

[0074] In the description according to this embodiment, the CS mode is selected in a case where the SOC of the battery 70 reaches the full charge threshold C as a result of the execution of the SOC recovery control. However, the invention is not specifically limited to this. In a case where the SOC of the battery 70 reaches the full charge threshold C as a result of the execution of the SOC recovery control and, for example, the vehicle malfunctions, the ECU 200 may select either the CS mode or the CD mode depending on the part where the malfunction occurs.

[0075] As another example, the ECU 200 may select the CS mode in a case where the SOC of the battery 70 reaches the full charge threshold C as a result of the execution of the SOC recovery control, and a malfunction has occurred in which the discharging of the battery 70 is blocked (for example, a failure of the second MG 30 and the battery 70). Alternatively, the ECU 200 may select the CD mode, which assigns priority to electric power consumption, in a case where, for example, the SOC of the battery 70 reaches the full charge threshold C as a result of the execution of the SOC recovery control, and a malfunction has occurred in which the charging of the battery 70 is blocked (for example, a failure of the first MG 20 and the engine 10).In this case, self-driving to a repair shop or the like is permitted in the case of the malfunction 1, and thus appropriate control can be selected depending on the part where the malfunction occurs.

[0076] In the description according to this embodiment, the SOC recovery switch 150 is hardware. However, for example, execution of the SOC recovery control may be requested by performing a touch operation on a predetermined area on a touch panel (touch panel) overlapping an image corresponding to the SOC recovery switch 150 displayed on a display in which the touch panel is arranged on a front surface of the display, or execution of the SOC recovery control may be requested by using a voice input device or the like.

[0077] In the description according to this embodiment, the SOC recovery control is executed when the CHG mode is selected. However, for example, the SOC recovery control may also be executed as a type of control in the CS mode using an unusual SOC target value.

[0078] In the description according to this embodiment, the CD mode is selected in a case where the stop of the SOC recovery control is requested by using the SOC recovery switch 150 during the execution of the SOC recovery control. However, for example, the starting of the engine 10 may be prohibited until a predetermined period of time elapses while the CD mode is selected. In this case, it can be ensured that the operation of the engine 10 is limited in a case where the OFF operation is performed on the SOC recovery switch 150 during the execution of the SOC recovery control. The above-described modification example can be implemented in part or in whole.

[0079] According to the aspect of the invention, the charge reduction mode in which the electric power of the electric power storage device is consumed is selected in a case where the stop of the recovery control is requested by using the switch during the execution of the recovery control. Accordingly, charging of the electric power storage device using the power of the engine is suppressed, giving priority to electric vehicle (EV) travel, which is travel in a state where the engine is stopped. Accordingly, the operation of the engine can be more restricted (for example, the operation of the engine is stopped and the state where the operation of the engine is stopped is maintained) than when the charge maintenance mode is selected.In this way, the operation of the machine can be limited to suit the user's intention.

[0080] According to the embodiment of the invention, the charge maintenance mode is selected when the electric power storage amount reaches the upper limit during the execution of the recovery control. Accordingly, the electric power storage amount can be maintained near the upper limit. Then, the electric power of the electric power storage device can be used at a timing desired by the user.

[0081] According to the embodiment of the invention, the charge maintenance mode is selected when the stop of the recovery control is requested by using the switch after the electric power storage amount reaches the upper limit during the execution of the recovery control. Accordingly, the electric power storage amount can be maintained near the upper limit. Accordingly, the electric power of the power storage device can be used at a timing desired by the user.

[0082] According to the embodiment of the invention, for example, the charge maintenance mode in which the engine operation is performed with a high frequency can be selected when a malfunction has occurred that blocks the discharging of the electric storage device (for example, a failure of the rotating electric machine and the electric power storage device). In addition, the charge reduction mode in which priority is given to the consumption of the electric power of the electric power storage device (operation of the rotating electric machine) can be selected when a malfunction has occurred that blocks the charging of the electric power storage device (for example, a failure of the electric power generation device and the engine).In this case, self-driving to a repair shop or the like is permitted in case of malfunction of the vehicle, and thus an appropriate control mode can be selected depending on the part in which the malfunction occurs (malfunctioning part).

[0083] As described above, a hybrid vehicle includes an engine (10), a rotating electric machine (30), an electric power storage device (70), an electric power generation device (20), a switch (150), and an ECU (200). The switch (150) is a switch operated by a user when the user requests execution or stopping of recovery control. The recovery control is control for increasing the electric power storage amount of the electric power storage device (70) by using the electric power generation device (20). The ECU (200) is configured to select any one of a plurality of control modes including a charge maintenance mode and a charge reduction mode, and to control the hybrid vehicle according to the selected control mode.The ECU (200) is configured to select the charge reduction mode when stopping the recovery control is requested by using the switch (150) during execution of the recovery control. List of reference symbols: 1 hybrid vehicle 8 gearboxes 10 machines 14 Vehicle wheel speed sensor 16 Output shaft 17 Drive shaft 20 first motor generator (first MG) 30 second motor generator (second MG) 40 Power distribution device 58 Slowdown device 60 Power Control Unit (PCU) 70 electrical power storage device 72 drive wheels 78 Loading device 11 cylinders 150 SOC recovery switches 152 Current sensor 154 Voltage sensor 154, 156 Battery temperature sensor 160 accelerator pedal 162 Pedal stroke sensor 200 ECU 202 CHG operating mode determination unit 204 OFF operation determination unit 206 Final determination unit 208 CD / CS mode selection unit 300 charging plugs 302 external electrical power supply 304 charging cable A switching threshold AP stroke size C Full charge threshold IB Battery current NL ground line Nw speed of the drive wheels PL power supply line Pr(1) Start threshold Pr(2) Start threshold S1 control signal S2 control signal TB Battery temperature V Vehicle speed VB Battery voltage

Claims

[1] Hybrid vehicle (1), characterized by : a machine (10), a motor generator (30) configured as a drive source for the hybrid vehicle (1), an electrical power storage device (70) configured to supply electrical power to the motor generator (30), a motor generator (20) configured to generate electrical power for charging the electrical power storage device (70) by using the power of the machine (10), a switch (150) for operation by a user when the user requests execution or stopping of a CHG mode, wherein the CHG mode is a mode in which an electric power storage amount of the electric power storage device (70) is increased by using the motor generator (20), wherein in the CHG mode, a control target value for the electric power storage amount of the electric power storage device (70) is a full charge threshold value (C), and the electric power storage amount is increased to the full charge threshold value (C), and an ECU (200) configured (a) selecting any one of a plurality of control modes, the control modes including a charge maintenance mode, a charge reduction mode, and the CHG mode, the charge maintenance mode being a mode in which a reduction in the electric power storage amount is suppressed, and the charge reduction mode being a mode in which the electric power of the electric power storage device (70) is consumed and the operation of the engine (10) for charging the electric power storage device (70) is suppressed, (b) to control the hybrid vehicle (1) according to the selected control mode, and (c) selecting the charge reduction mode when stopping the CHG mode is requested by using the switch (150) while the CHG mode is selected, wherein the ECU (200) is configured to select the charge maintenance mode when increasing the amount of electric power stored in the electric power storage device (70) is stopped while the CHG mode is selected. [2] The hybrid vehicle (1) according to claim 1, wherein the ECU (200) is configured to select the charge maintenance mode when the increase in the amount of electric power stored in the electric power storage device (70) is completed and a stop of the CHG mode is requested while the CHG mode is selected. [3] The hybrid vehicle (1) according to claim 1, wherein the ECU (200) is configured to select the charge maintenance mode or the charge reduction mode depending on a malfunctioning part of the hybrid vehicle (1) when the increase in the amount of electric power stored in the electric power storage device (70) is completed and the malfunctioning part is present in the hybrid vehicle (1).

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