Electric vehicle control device

Abstract

To provide a control device of an electric vehicle which can inhibit temperature rise of each device caused by exhaust heat of an internal combustion engine generating electric power.SOLUTION: A control device of an electric vehicle includes: an internal combustion engine mounted on an electric vehicle; a first rotary electric machine connected to the internal combustion engine; a second rotary electric machine which may drive a driving shaft of the electric vehicle; and a driving battery which may supply electric power to the second rotary electric machine. The control device of the electric vehicle executes power generation control, in which the driving shaft is driven by the second rotary electric machine and the first rotary electric machine is driven by the output of the internal combustion engine to generate electric power, and motoring control in which continuation of the power generation control is prohibited to stop the output from the internal combustion engine and electric power supplied from the driving battery to the second rotary electric machine is increased to drive the internal combustion engine with the first rotary electric machine when predetermined conditions are met during the power generation control.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a control device for an electric vehicle. [Background technology]

[0002] Conventionally, there is known a control device for an electric vehicle equipped with a heater that warms a catalyst of an exhaust purification device (see, for example, Patent Document 1). The control device for an electric vehicle in Patent Document 1 promotes catalyst activation by warming up the catalyst with the heater. The control device for an electric vehicle in Patent Document 1 cools the heater by motoring the internal combustion engine so that the heater does not overheat. Motoring of the internal combustion engine is achieved by driving the internal combustion engine with a motor connected to the internal combustion engine. In the control device for an electric vehicle in Patent Document 1, the motor is driven by using regenerative energy generated when the electric vehicle decelerates. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-227039 A Summary of the Invention [Problem to be solved by the invention]

[0004] The control device for an electric vehicle in Patent Document 1 focuses on the effective use of regenerative energy by using it to cool the heater to prevent excessive heating. However, in such an electric vehicle, the devices of the internal combustion engine may be overheated by the exhaust heat of the internal combustion engine while it is generating electricity. In other words, regardless of the presence or absence of regenerative energy, the devices of the internal combustion engine may be increased in temperature by the exhaust heat.

[0005] An object of the present disclosure is to provide a control device for an electric vehicle that can suppress a temperature rise in each device due to exhaust heat from an internal combustion engine during power generation. [Means for solving the problem]

[0006] The control device for an electric vehicle according to the present disclosure is a control device for an electric vehicle equipped with an internal combustion engine mounted on the electric vehicle, a first rotating electric machine connected to the internal combustion engine, a second rotating electric machine capable of driving a drive shaft of the electric vehicle, and a drive battery capable of supplying power to the second rotating electric machine. The control device for an electric vehicle performs power generation control in which the drive shaft is driven by the second rotating electric machine while the first rotating electric machine is driven by the output of the internal combustion engine to generate power, and during the power generation control, Caused by rising exhaust pipe temperatures When a predetermined condition is met, the continuation of power generation control is prohibited, output from the internal combustion engine is stopped, and motoring control is executed to increase the power supplied from the driving battery to the second rotating electric machine and motor the internal combustion engine by the first rotating electric machine.

[0007] According to this control device for an electric vehicle, when a predetermined condition is met during power generation control, the continuation of power generation control is prohibited and motoring is performed. As a result, outside air from the electric vehicle is blown into the exhaust pipe of the internal combustion engine. When outside air flows into the exhaust pipe of the internal combustion engine, the exhaust pipe is cooled. When the exhaust pipe, which is the main heat source of the internal combustion engine, is cooled, the temperature of each device near the exhaust pipe of the electric vehicle, for example, also decreases. As a result, each device of the internal combustion engine is cooled. Therefore, it is possible to suppress the temperature rise of each device due to the exhaust heat of the internal combustion engine during power generation. Effect of the Invention

[0008] According to the present disclosure, it is possible to provide a control device for an electric vehicle that can suppress a temperature rise in each device due to exhaust heat from an internal combustion engine during power generation. [Brief description of the drawings]

[0009] [Figure 1] 1 is a system diagram of an electric vehicle according to an embodiment of the present disclosure. [Diagram 2] 1 is a system diagram of an internal combustion engine mounted on an electric vehicle according to an embodiment of the present disclosure. [Diagram 3] 4 is a flowchart showing a control procedure of a control device for an electric vehicle according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings.

[0011] 1, the electric vehicle 1 according to this embodiment is a four-wheel drive hybrid vehicle. The electric vehicle 1 has an internal combustion engine (ENG) 2, a generator (GEN: an example of a first rotating electric machine) 4, a front motor (FrM: an example of a second rotating electric machine) 6, a rear motor (RM) 8, a driving battery (BT) 10, a control device (HVECU) 20, an accelerator pedal 21, and an external power supply device 22.

[0012] In the electric vehicle 1 of this embodiment, the front motor 6 drives the front wheel drive shaft 12a of the front wheels 12 via a transaxle 16. The rear motor 8 drives the rear wheel drive shaft 14a of the rear wheels 14 via a reduction gear 8c. The front motor 6 is connected to the drive battery 10 via a front inverter 18, and is supplied with electric power (second electric power) from the drive battery 10.

[0013] The front inverter 18 has a front motor control device (FrMCU) 6a and a generator control device (GCU) 4a that controls the generator 4. The front motor control device 6a receives signals from the control device 20 and controls the regeneration and power running of the front motor 6 so that the front motor 6 is in a desired operating state. The rear motor 8 is similarly connected to the drive battery 10 via the rear inverter 8b and is supplied with power (second power) from the drive battery 10. The rear inverter 8b has a rear motor control device (RMCU) 8a. The rear motor control device 8a receives signals from the control device 20 and controls the regeneration and power running of the rear motor 8 so that the rear motor 8 is in a desired operating state.

[0014] The internal combustion engine 2 drives the generator 4 via the transaxle 16. The internal combustion engine 2 is driven by the combustion of fuel supplied from a fuel tank (Fuel TANK) 23. Various devices and sensors of the internal combustion engine 2 are electrically connected to an engine control device (ENG-ECU) 2a. The engine control device 2a acquires a signal from a control device 20 and controls the internal combustion engine 2 to be in a desired operating state. The transaxle 16 amplifies the rotation speed of the internal combustion engine 2 and transmits it to the generator 4. The transaxle 16 of this embodiment also has a clutch (an example of a disconnecting mechanism) 16a. The clutch 16a transmits and disconnects power between the internal combustion engine 2 and the front motor 6 and between the internal combustion engine 2 and the front wheel drive shaft 12a. The internal combustion engine 2 is connected to the front wheel drive shaft 12a via the clutch 16a of the transaxle 16 and drives the front wheel drive shaft 12a.

[0015] As shown in FIG. 2, the internal combustion engine 2 has at least a fuel injection valve 2c, an exhaust pipe 2d, and an exhaust purification device 2e. In this embodiment, the internal combustion engine 2 is a rear exhaust type in which the exhaust pipe 2d extends from the internal combustion engine 2 toward the rear of the electric vehicle 1. The internal combustion engine 2 is connected to the exhaust purification device 2e via the exhaust pipe 2d. In this embodiment, the internal combustion engine 2 is a multi-injection gasoline engine. The internal combustion engine 2 injects fuel using a fuel injection valve 2c arranged in an intake port 2f, and adjusts the amount of intake air using a throttle valve 2b to adjust the output. However, the internal combustion engine 2 may be a direct injection gasoline engine or diesel engine that directly injects fuel into the cylinder 2g. Furthermore, the internal combustion engine 2 may be a gasoline engine that uses both the multi-injection system and the direct injection system. The internal combustion engine 2 may also include devices such as an exhaust recirculation system including an exhaust recirculation valve 2i and an exhaust recirculation passage 2j.

[0016] The exhaust purification device 2e purifies the exhaust gas from the internal combustion engine 2. In this embodiment, the exhaust purification device 2e is a three-way catalyst that purifies the exhaust gas by oxidizing or reducing hydrocarbons, carbon monoxide, and nitrogen oxides contained in the exhaust gas. Such a three-way catalyst detects the purification state by a sensor (a linear air-fuel ratio sensor or an oxygen sensor in this embodiment) 2h arranged at least upstream of the exhaust purification device 2e. However, the exhaust purification device 2e may also include a catalyst having an oxygen storage function or a nitrogen storage function. Furthermore, the exhaust purification device 2e may include a device such as a gasoline particulate filter or a diesel particulate filter that stores unburned fuel.

[0017] As shown in FIG. 1, the generator 4 is connected to the internal combustion engine 2 and generates electricity by being driven by the internal combustion engine 2. The electric power (first electric power) generated by the generator 4 can charge the drive battery 10 and can be supplied to the front motor 6 and the rear motor 8 (hereinafter referred to as the motors in the specification) via the front inverter 18 and the rear inverter 8b. In this embodiment, the generator 4 is a motor generator, and in addition to generating electricity, it can motor the internal combustion engine 2 by rotating and driving the internal combustion engine 2. When driven by the internal combustion engine 2, the generator 4 generates electricity by applying a load to the generator 4. On the other hand, the generator 4 is supplied with electric power from the drive battery 10 and powers the internal combustion engine 2 to motor it. The generator 4 is controlled by a generator control device 4a provided in the front inverter 18. The generator control device 4a is electrically connected to the control device 20, receives a signal from the control device 20, and controls the power generation and power running so that the generator 4 is in a desired operating state.

[0018] The driving battery 10 is composed of a secondary battery such as a lithium ion battery, and has a battery module (not shown) composed of multiple battery cells. The driving battery 10 functions as a power source for each motor. The driving battery 10 also has a battery monitoring unit (BMU) 10a that calculates the charging rate (State Of Charge, hereinafter referred to as SOC) of the battery module, detects the deterioration state (State Of Health, hereinafter referred to as SOH) of the battery module, and detects the voltage Bv and battery temperature Btmp of the battery module. The battery monitoring unit 10a obtains the voltage Bv, charging rate SOC, deterioration state SOH, and battery temperature Btmp of the driving battery 10 and transmits them to the control device 20.

[0019] The control device 20 executes at least a control for switching the driving mode, a power generation control for causing the internal combustion engine 2 to generate power in each driving mode, and a motoring control for driving the internal combustion engine 2 by the generator 4.

[0020] In this embodiment, the control device 20 switches the driving mode to one of the parallel mode, series mode, and EV mode by controlling the clutch 16a based on information such as the speed V, the charging rate SOC, and the accelerator opening Th. In the parallel mode, the control device 20 connects the clutch 16a and drives the front wheel drive shaft 12a by both the internal combustion engine 2 and the front motor 6. At this time, the front motor 6 is supplied with either or both of electric power (second electric power) from the drive battery 10 and electric power (first electric power) generated by the generator 4. Similarly, the rear motor 8 is supplied with either or both of electric power (second electric power) from the drive battery 10 and electric power (first electric power) generated by the generator 4 to drive the rear wheel drive shaft 14a. In EV mode, the control device 20 releases the clutch 16a and supplies power (second power) from the drive battery 10 to each motor, which drives the front wheel drive shaft 12a and the rear wheel drive shaft 14a (hereinafter referred to as each drive shaft in the specification).

[0021] In the series mode, the control device 20 releases the clutch 16a, drives the generator 4 with the internal combustion engine 2, and supplies the first electric power generated by the generator 4 to each motor. Furthermore, if the first electric power is insufficient to provide the driving force for each motor to drive each drive shaft, the control device 20 also supplies the second electric power from the drive battery 10 to each motor. Note that in the parallel mode and series mode, the drive battery 10 may be charged by supplying a portion of the electric power generated by the internal combustion engine 2 to the drive battery 10.

[0022] The control device 20 calculates an engine required torque (an example of a required output value) ETq required of the internal combustion engine 2 in each of the driving modes, namely, the parallel mode, the series mode, and the EV mode, and transmits the calculated torque to the engine control device 2a. The engine control device 2a obtains the engine required torque ETq and controls the internal combustion engine 2 so as to achieve the engine required torque ETq. The control device 20 is actually configured by a microcomputer including a calculation device, a memory, an input / output buffer, and the like. The control device 20 controls each device based on signals from each sensor and various devices, as well as maps and programs stored in the memory, so that the electric vehicle 1 is in a desired operating state.

[0023] In this embodiment, various control devices including the engine control device 2a, the generator control device 4a, the front motor control device 6a, the rear motor control device 8a, and the battery monitoring unit 10a are provided separately from the control device 20. The various control devices are electrically connected to the control device 20. However, the various control devices may be provided integrally with the control device 20. Like the control device 20, the various control devices are configured by microcomputers including a calculation device, a memory, an input / output buffer, and the like.

[0024] The accelerator pedal 21 is a pedal that is depressed by the driver of the electric vehicle 1 to control the acceleration and deceleration of the electric vehicle 1. An accelerator position sensor 21a that detects the depression position of the accelerator pedal 21 is provided on the accelerator pedal 21. The accelerator position sensor 21a is electrically connected to the control device 20 and transmits the accelerator depression position (accelerator opening degree) to the control device 20.

[0025] The external power supply device 22 is a device for supplying power from the driving battery 10 to electrical equipment (one example of an external device, such as a home appliance) prepared by the user of the electric vehicle 1 separately from the electric vehicle 1. The external power supply device 22 includes an inverter, and converts DC current from the driving battery 10 into AC current suitable for the electrical equipment.

[0026] Next, a control procedure of the control device 20 of this embodiment will be described with reference to the flowchart of Fig. 3. The control device 20 starts a control operation when an ignition switch (not shown) is turned on.

[0027] When the control device 20 starts the control operation, in step S1, it determines whether or not power generation control is in progress. Here, power generation control in progress indicates a state in which control is being executed to drive the generator 4 by the internal combustion engine 2 to generate power. A state in which such power generation control is necessary is, for example, when the electric vehicle 1 is traveling in series mode, the driver depresses the accelerator pedal 21, increasing the output (driver required torque) to be output to each motor, and requiring a first electric power. Also, for example, when external power supply control is in progress in which the external power supply device 22 supplies power to an external electrical device, the charging rate SOC of the driving battery 10 has decreased and charging is required.

[0028] During power generation control, the control device 20 calculates the engine required torque ETq from the amount of electric power generated by the generator 4. The control device 20 operates the internal combustion engine 2 by transmitting the engine required torque ETq to the engine control device 2a. If the engine required torque ETq continues to increase, the exhaust heat of the internal combustion engine 2 increases the temperature of the exhaust pipe 2d and the exhaust purification device 2e. This increases the temperature of the catalyst of the exhaust purification device 2e, and there is a risk of the purification performance of the catalyst decreasing. In addition, when the temperature of the exhaust pipe 2d increases, the temperature of devices mounted on the dash panel of the electric vehicle 1, such as a power steering device, tends to increase. In particular, during external power supply control, if the electric vehicle 1 is stopped, the exhaust pipe 2d is not cooled by the running wind, and the temperature of these devices tends to increase.

[0029] Therefore, in step S1, the control device 20 determines whether or not power generation control is in progress. If the control device 20 determines in step S1 that power generation control is not in progress (NO in step S1), the control device 20 returns the process to step S1.

[0030] If the control device 20 determines in step S1 that power generation control is in progress (YES in step S1), the control device 20 advances the process from step S1 to step S2. In step S2, the control device 20 determines whether or not external power supply control is in progress. If the control device 20 determines in step S2 that external power supply control is not in progress (NO in step S2), the control device 20 advances the process to step S3. If the control device 20 determines in step S2 that external power supply control is in progress (YES in step S2), the control device 20 advances the process to step S10.

[0031] In step S3, the control device 20 determines whether a predetermined condition is satisfied. In this embodiment, the predetermined condition is, for example, a case where the engine required torque ETq increases and becomes equal to or greater than a first predetermined value ETq1. However, the predetermined condition may be another condition that is caused by an increase in the temperatures of the exhaust pipe 2d and the exhaust purification device 2e. For example, the predetermined condition may be a case where the exhaust temperature becomes equal to or greater than a predetermined temperature, a case where the temperature of the cooling water of the internal combustion engine 2 becomes equal to or greater than a predetermined temperature, etc.

[0032] In step S10, the control device 20 determines whether the engine required torque ETq is equal to or greater than a second predetermined value ETq2 that is smaller than the first predetermined value ETq1. If the control device 20 determines that the engine required torque ETq is equal to or greater than the second predetermined value ETq2 (YES in step S10), the control device 20 proceeds to the process of step S4. On the other hand, if the control device 20 determines that the engine required torque ETq is less than the second predetermined value ETq2 in step S10 (NO in step S10), the control device 20 proceeds to the process before step S1.

[0033] As described above, the temperature of the exhaust pipe 2d is likely to rise during external power supply control because there is no wind caused by running. Therefore, the control device 20 performs the process from step S2 through step S10 to step S5 described later, thereby executing the motoring control when the engine required torque ETq is equal to or greater than a second predetermined value ETq2 that is smaller than the first predetermined value ETq1. This allows the control device 20 to further suppress the temperature rise of the exhaust pipe 2d during external power supply control.

[0034] If the control device 20 determines in step S3 that the predetermined condition is satisfied (step S3: YES), the control device 20 proceeds to step S4. In step S4, the control device 20 determines whether the charging rate SOC of the driving battery 10 is equal to or higher than a predetermined charging rate SOCt. If the control device 20 determines that the charging rate SOC of the driving battery 10 is equal to or higher than the predetermined charging rate SOCt (step S4: YES), the control device 20 proceeds to step S5. In step S5, the control device 20 prohibits continuation of power generation control and executes motoring control. Specifically, the control device 20 executes motoring control by having the engine control device 2a open the throttle valve 2b and rotating the internal combustion engine 2 with the generator 4. This causes outside air to flow from the intake port 2f toward the exhaust pipe 2d, cooling the exhaust pipe 2d. If the control device 20 determines that the predetermined condition is not satisfied (step S3: NO), the control device 20 returns the process to before step S1.

[0035] On the other hand, when the state of charge SOC is less than the predetermined state of charge SOCt (step S4 NO), the control device 20 proceeds to step S11. In step S11, enrichment control is executed, and the process returns to before step S1. The control device 20 executes enrichment control to make the fuel injection amount richer than the theoretical air-fuel ratio, thereby cooling the exhaust pipe 2d with fuel. When enrichment control is executed, total hydrocarbons (THC) and carbon monoxide (CO) are likely to be discharged. However, according to the control procedure of the control device 20 of this embodiment, enrichment control is executed only when the state of charge SOC of the driving battery 10 is less than the predetermined state of charge SOCt. For this reason, the cooling of the exhaust purification device 2e is exclusively performed by motoring control. As a result, total hydrocarbons (THC) and carbon monoxide (CO) are unlikely to be discharged. On the other hand, when the state of charge SOC is less than the predetermined state of charge SOCt, the control device 20 executes enrichment control to suppress an excessive decrease in the output of the driving battery 10 due to the motoring control.

[0036] When the control device 20 executes motoring control during series running control in which the electric vehicle 1 is run in the series mode, the control device 20 controls the supply power to be supplied to each motor, which is reduced due to the prohibition of power generation control during the motoring control, to be compensated for by the second power supplied from the drive battery 10 to each motor. Specifically, the control device 20 reduces the output of the internal combustion engine 2 by the motoring control, and finally makes it zero. The control device 20 calculates the power (supply power) that was scheduled to be generated by the internal combustion engine 2 during this period, and compensates for this supply power by the second power from the drive battery 10. In this way, the control device 20 prohibits series running and performs motoring, even though the required load (e.g., driver required torque) on the electric vehicle 1 has increased. The control device 20 compensates for the increase in the required load by increasing the power supplied from the drive battery 10 to each motor. In this way, the control device 20 prevents the acceleration performance of the electric vehicle 1 from decreasing while performing motoring. The control device 20 also executes motoring control in the series mode. In the series mode, the clutch 16a is in a disengaged state. For this reason, the rotational fluctuation of the internal combustion engine 2 is not directly transmitted to the drive shaft. As a result, the control device 20 can easily ensure a degree of freedom in motoring control.

[0037] Furthermore, in step S4, the control device 20 determines whether the charging rate SOC is equal to or higher than a predetermined charging rate SOCt. Therefore, even when the supplied power is supplemented by the second power, the control device 20 suppresses an excessive decrease in the charging rate SOC of the driving battery 10. In other words, the predetermined charging rate SOCt may be a charging rate SOC that allows the supplied power to be supplemented by the second power. In this embodiment, the predetermined charging rate SOCt may be a charging rate SOC that allows the driving battery 10 to output, for example, power equivalent to the supplied power plus a transmission loss.

[0038] The control device 20 starts motoring control in step S5, and proceeds to step S6. In step S6, the control device 20 determines whether or not the time T has elapsed beyond the predetermined time Tp since the motoring control was executed. If the control device 20 determines that the time T has elapsed beyond the predetermined time Tp (step S6 YES), the control device 20 proceeds to step S7 and ends the motoring control. The control device 20 may perform fault diagnosis control of the exhaust recirculation device and the exhaust recirculation valve 2i during the motoring control. Faults in the exhaust recirculation device are easily determined by flowing outside air into the exhaust recirculation passage 2j by the motoring control. If the control device 20 determines that the predetermined time Tp has not elapsed since the motoring control was executed (step S6 NO), the control device 20 returns to the process before step S5 and continues the motoring control.

[0039] Here, the greater the increase in the engine required torque ETq before the motoring control is started, the greater the amount of heat in the exhaust. As a result, the temperature of the exhaust pipe 2d is more likely to rise. Therefore, the control device 20 may determine the predetermined time T based on the engine required torque ETq that has increased before the motoring control is started. One example of the increased engine required torque ETq may be the increase in the engine required torque ETq during a certain period until the engine required torque ETq becomes equal to or greater than the first predetermined value ETq1. Another example of the increased engine required torque ETq may be the increase rate of the engine required torque ETq (the increase in the engine required torque ETq per unit time) until the engine required torque ETq becomes equal to or greater than the first predetermined value ETq1. In this embodiment, the control device 20 lengthens the motoring time as the increased engine required torque ETq is larger. Also, the higher the increase rate of the engine required torque ETq, the longer the motoring time. As a result, the more likely the temperature of the exhaust pipe 2d is to rise, the control device 20 can lengthen the cooling time of the exhaust pipe 2d by the motoring control.

[0040] When the control device 20 determines that a predetermined time Tp or more has elapsed since the motoring control was executed (step S6 YES), the control device 20 proceeds to the process of step S7 and ends the motoring control. When a transition occurs during the motoring control from the required output value of the internal combustion engine 2 in the power generation control before the motoring control to the required output value to be output by the internal combustion engine 2 in the power generation control after the motoring, the control device 20 resumes the operation of the internal combustion engine 2 by the transitioned required output value after the motoring control ends. Specifically, when the engine required torque ETq transitions during the motoring control, the control device 20 operates the internal combustion engine 2 by the transitioned engine required torque ETq after the motoring control ends, and resumes the power generation control. For example, it is assumed that a transition occurs from the engine required torque ETq3 before the motoring control to the engine required torque ETq4 after the motoring control ends. The control device 20 operates the internal combustion engine 2 by the transitioned engine required torque ETq4 after the motoring control ends. In this way, the control device 20 suppresses deterioration of the power generation efficiency.

[0041] When the motoring control is ended, the control device 20 proceeds to step S8. In step S8, the control device 20 acquires a catalyst temperature CT, which is the temperature of the catalyst arranged in the exhaust purification device 2e, and determines whether the catalyst temperature CT is equal to or higher than a predetermined temperature CTp. The control device 20 may acquire the catalyst temperature CT by estimating it from, for example, the output of the internal combustion engine 2. If a temperature sensor is arranged in the exhaust purification device 2e, the control device 20 may acquire the catalyst temperature CT from the temperature sensor. The predetermined temperature CTp may be, for example, a temperature at which the catalyst is activated (e.g., 400°C).

[0042] When the control device 20 judges that the catalyst temperature CT is equal to or higher than the predetermined temperature CTp (step S8 YES), the control device 20 advances the process to step S9. In step S9, the control device 20 executes the first oxygen purge control and returns the process to before step S1. During motoring control, oxygen is likely to be stored in the catalyst of the exhaust purification device 2e. For this reason, the control device 20 releases the oxygen stored in the exhaust purification device 2e by executing the first oxygen purge control or the second oxygen purge control described later. During the first oxygen purge control, the control device 20 increases the fuel injection amount of the internal combustion engine 2. As a result, the control device 20 creates an excess state of total hydrocarbons (THC) and carbon monoxide (CO) in the exhaust from the internal combustion engine 2. As a result, the oxidation action of the catalyst is promoted and the oxygen in the catalyst is released.

[0043] When the control device 20 determines that the catalyst temperature CT is lower than the predetermined temperature CTp (step S8 NO), the control device 20 advances the process to step S12. In step S12, the control device 20 executes the second oxygen purge control and returns the process to before step S1. When the internal combustion engine 2 is a direct injection type engine, during the second oxygen purge control, the control device 20 increases the fuel injection amount in the exhaust stroke as in the first oxygen purge control, thereby simultaneously raising the catalyst temperature and purging oxygen. When the internal combustion engine 2 is a multi-injection type engine, during the second oxygen purge control, the control device 20 cuts ignition and executes a small amount of fuel injection in the exhaust stroke. At this time, when the internal combustion engine 2 has a variable valve timing device, the control device 20 sets the variable valve timing device to the most advanced position. This allows the control device 20 to raise the catalyst temperature and purge oxygen simultaneously.

[0044] As described above, the present disclosure can provide a control device 20 for an electric vehicle 1 that can suppress a temperature rise in each device due to exhaust heat from the internal combustion engine 2 during power generation.

[0045] <Other embodiments> Although the embodiment of the present disclosure has been described above, the present disclosure is not limited to the above embodiment, and various modifications are possible without departing from the gist of the invention. In particular, the multiple modifications described in this specification can be arbitrarily combined as necessary.

[0046] (a) In the above embodiment, a four-wheel drive hybrid vehicle has been described as an example, but the present disclosure is not limited thereto. The electric vehicle 1 may be a front-wheel drive hybrid vehicle or a plug-in hybrid vehicle. The electric vehicle 1 may also be a four-wheel drive plug-in hybrid vehicle.

[0047] (b) In the above embodiment, the clutch 16a is used to connect the internal combustion engine 2 and the front wheel drive shaft 12a, but the present disclosure is not limited to this. The internal combustion engine 2 and the front wheel drive shaft 12a may be connected via a planetary gear.

[0048] (c) In the above embodiment, an example has been described in which the internal combustion engine 2 and the generator 4 are connected by gears, but the present disclosure is not limited to this. The internal combustion engine 2 and the generator 4 may be connected via planetary gears. [Explanation of symbols]

[0049] 1: electric vehicle, 2: internal combustion engine, 4: generator (an example of a first rotating electric machine) 6: Front motor (an example of a second rotating electric machine), 10: Driving battery 16a: Clutch (an example of a disconnecting mechanism) 20: Control device, 22: External power supply device ETq: Engine required torque (an example of required output value) ETq1: 1st predetermined value ETq2: Second predetermined value CT: Catalyst temperature

Claims

1. A control device for an electric vehicle including an internal combustion engine mounted on the electric vehicle, a first rotating electric machine connected to the internal combustion engine, a second rotating electric machine capable of driving a drive shaft of the electric vehicle, and a drive battery capable of supplying electric power to the second rotating electric machine, a power generation control for driving the drive shaft by the second rotating electric machine while driving the first rotating electric machine with an output of the internal combustion engine to generate power; a motoring control in which, when a predetermined condition caused by a temperature rise in an exhaust pipe is satisfied during the power generation control, continuation of the power generation control is prohibited, output from the internal combustion engine is stopped, and the electric power supplied from the driving battery to the second rotating electric machine is increased, thereby motoring the internal combustion engine by the first rotating electric machine; A control device for an electric vehicle that executes the above.

2. The predetermined condition is that an exhaust temperature of the exhaust pipe of the internal combustion engine becomes equal to or higher than a first predetermined temperature during the power generation control. The control device for an electric vehicle according to claim 1.

3. The predetermined condition is that the temperature of the cooling water of the internal combustion engine becomes equal to or higher than a second predetermined temperature during the power generation control. The control device for an electric vehicle according to claim 1.

4. The predetermined condition is a case where a required output value to be output by the internal combustion engine increases during the power generation control and becomes equal to or greater than a first predetermined value. The control device for an electric vehicle according to claim 1.

5. continuing the motoring control for a predetermined time period determined based on the increased required output value; The control device for an electric vehicle according to claim 4.

6. the electric vehicle further includes an external power supply device capable of supplying electric power from the driving battery to an external device connected to the electric vehicle; During external power supply control for controlling the external power supply device in a state in which the electric vehicle is stopped, when the value of the first predetermined value is equal to or greater than a second predetermined value that is smaller than the first predetermined value, the motoring control is executed. The control device for an electric vehicle according to claim 4 or 5.

7. During the motoring control, when a transition occurs from a required output value of the internal combustion engine in the power generation control before the motoring control to a required output value to be output by the internal combustion engine in the power generation control after the motoring, After the motoring control is ended, the operation of the internal combustion engine is resumed based on the transitioned required output value. The control device for an electric vehicle according to any one of claims 1 to 6.

8. The electric vehicle further includes a connection / disconnection mechanism that transmits or disconnects power between the internal combustion engine and the drive shaft, executing a series running control in which a first electric power generated by the first rotating electric machine is supplied to the second rotating electric machine or the driving battery with the disconnecting mechanism being disconnected during the power generation control; When the motoring control is executed during the series traveling control, the supply power to be supplied to the second rotating electric machine, which is reduced due to the prohibition of the power generation control during the motoring control, is compensated for by the second electric power supplied from the driving battery to the second rotating electric machine. The control device for an electric vehicle according to any one of claims 1 to 7.

9. When the driving battery has a predetermined charging rate or higher, the motoring control is executed. When the driving battery is less than the predetermined charging rate, enrichment control is executed by the internal combustion engine to make the fuel richer than the stoichiometric air-fuel ratio. The control device for an electric vehicle according to any one of claims 1 to 8.

10. executing a fault diagnosis control of a device mounted on the electric vehicle during the motoring control; The control device for an electric vehicle according to any one of claims 1 to 9.

11. The electric vehicle further includes an exhaust purification device that purifies exhaust gas from the internal combustion engine. When the motoring control is terminated, a temperature of the exhaust gas purification device is acquired, and an oxygen purge control is executed in accordance with the temperature. The control device for an electric vehicle according to any one of claims 1 to 10.

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