JP2017177968A - Control device for hybrid vehicle and hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To compensate shortage of target torque caused by a decline in output torque of a drive motor without making a driver feel uncomfortable when the drive motor is locked.SOLUTION: A control device for a hybrid vehicle includes: an engine that can output driving force to drive driving wheels; and a first motor generator and a second motor generator that can output the driving force to drive the driving wheels independently of each other. The control device for the hybrid vehicle further includes a traveling mode setting section for setting a traveling mode of the hybrid vehicle in accordance with the traveling state. During a first traveling mode of driving the driving wheels by using output of the second motor generator, when a temperature of the second motor generator exceeds a threshold value, the traveling mode setting section enables switching to a second traveling mode of driving the driving wheels by using at least output of the first motor generator.SELECTED DRAWING: Figure 10

Description

  The present invention relates to a hybrid vehicle control device and a hybrid vehicle.

  In recent years, a hybrid vehicle (HEV) including an engine and a drive motor is known as a driving force source for driving the driving wheels of the vehicle. The hybrid vehicle can be configured to be able to switch between a plurality of travel modes in which combinations of operating states of the engine and the motor are different from each other. For such a hybrid vehicle, a technique related to switching of a driving mode has been proposed.

  For example, in Patent Document 1, in a hybrid vehicle using an engine and a plurality of motors as a driving force source, to smoothly switch from a state of traveling by the output of the engine to a state of traveling by the outputs of the plurality of motors. In addition, a first traveling mode for traveling the vehicle by the output of the engine, a second traveling mode for traveling the vehicle by the output of a plurality of motors, and a third traveling mode for traveling the vehicle by the output of any one of the motors. In the hybrid vehicle control device that selects and sets one of them according to the required driving force for the vehicle, the detection means for obtaining the magnitude of the output of the driving force source, and the second traveling mode according to the magnitude of the output A technology including setting means for changing selectability is disclosed.

Japanese Patent Laying-Open No. 2015-020486

  By the way, in a hybrid vehicle, for example, when climbing a steep slope or overcoming a step, a high load is applied to the drive motor that drives the drive wheels, and a lock state in which the drive motor does not rotate may occur. is there. For example, the drive motor may be locked during the travel mode in which the vehicle travels by the output of the drive motor among the travel modes of the hybrid vehicle. Specifically, since a three-phase AC motor is used as the drive motor, when the drive motor is locked, a relatively large current continuously flows to one phase of the drive motor, so that the drive motor May be heated excessively.

  Here, when the drive motor is locked, the target value of the output of the drive motor is reduced, thereby reducing the power supplied to the drive motor, thereby preventing the drive motor from being overheated. Can do. In this way, when the output of the drive motor is reduced, it is conceivable that the engine output is compensated for the shortage of the target torque, which is the target value of the torque transmitted to the drive wheels, by starting the engine. . However, starting the engine during the travel mode in which the vehicle travels based on the output of the drive motor can be a factor that makes the driver feel uncomfortable.

  Accordingly, the present invention has been made in view of the above problems, and the object of the present invention is to reduce the output of the drive motor without causing the driver to feel strange when the drive motor is locked. An object of the present invention is to provide a hybrid vehicle control device and a hybrid vehicle capable of compensating for a shortage of target torque.

  In order to solve the above problems, according to an aspect of the present invention, an engine capable of outputting a driving force for driving a driving wheel and a driving force for driving the driving wheel can be independently output. A control apparatus for a hybrid vehicle comprising a first motor generator and a second motor generator, comprising: a travel mode setting unit that sets a travel mode of the hybrid vehicle according to a travel state; The mode setting unit is configured to perform at least the first motor when the temperature of the second motor generator exceeds a threshold during the first traveling mode in which the driving wheel is driven by the output of the second motor generator. There is provided a control device for a hybrid vehicle that switches to a second travel mode in which the drive wheels are driven using the output of a generator.

  An output limiting unit may be provided that limits the output of the second motor generator when the temperature of the second motor generator exceeds the limit temperature, and the threshold value may be set to the limit temperature.

  An output limiting unit that limits the output of the second motor generator when the temperature of the second motor generator exceeds a limit temperature, and the threshold value may be set to a temperature lower than the limit temperature. .

  A first motor torque calculation unit that calculates a first torque command value that is a torque command value of the first motor generator, and a second torque command value that is a torque command value of the second motor generator A second motor torque calculation unit that reduces the second torque command value when switching to the second travel mode is performed, and The first motor torque calculation unit subtracts the second torque command value from a target torque that is a target value of torque transmitted to the drive wheels when switching to the second traveling mode is performed. The value obtained in this way may be calculated as the first torque command value.

  The second motor torque calculation unit decreases the second torque command value so that the second torque command value approaches a predetermined value when switching to the second traveling mode is performed. May be.

  The travel mode setting unit may switch to the first travel mode when the temperature of the second motor generator falls below a predetermined first temperature during the second travel mode.

  When the threshold value is set as the first threshold value, the travel mode setting unit is configured such that the first motor generator temperature exceeds the second threshold value during the second travel mode. You may switch to the running mode.

  When the threshold value is the first threshold value, and the temperature of the first motor generator exceeds the second threshold value during the second travel mode, the first motor torque calculation unit is The first torque command value is decreased, and the second motor torque calculation unit obtains a value obtained by subtracting the first torque command value from a target torque that is a target value of torque transmitted to the drive wheels. The second torque command value may be calculated.

  The travel mode setting unit is configured such that the temperature of the first motor generator is lower than a predetermined second temperature when the temperature of the second motor generator exceeds the threshold during the first travel mode. In addition, when the remaining capacity of the battery that supplies power to the first motor generator is greater than or equal to a predetermined remaining capacity, the mode may be switched to the second traveling mode.

  An engine capable of outputting a driving force for driving the driving wheels, a first motor generator and a second motor generator capable of independently outputting a driving force for driving the driving wheels, and the control device A hybrid vehicle may be provided.

  As described above, according to the present invention, when the drive motor is locked, it is possible to compensate for a shortage of the target torque due to a decrease in the output of the drive motor without causing the driver to feel uncomfortable.

It is explanatory drawing which shows an example of transition of various state quantities in case control which compensates the shortage of a target torque with the output of an engine is performed when a drive motor locks. It is a mimetic diagram showing an example of schematic structure of a drive system of a hybrid vehicle concerning an embodiment of the present invention. It is explanatory drawing for demonstrating the single motor EV driving mode in the drive system which concerns on the same embodiment. It is explanatory drawing for demonstrating the twin motor EV driving mode in the drive system which concerns on the embodiment. It is explanatory drawing for demonstrating the engine travel mode in the drive system which concerns on the same embodiment. It is explanatory drawing for demonstrating the hybrid travel mode in the drive system which concerns on the same embodiment. It is explanatory drawing which shows an example of a function structure of hybrid ECU which concerns on the embodiment. It is explanatory drawing which shows an example of the map showing the relationship between the temperature of a 2nd motor generator, and a 2nd motor generator target torque. It is a flowchart which shows an example of the process flow in the single motor EV driving mode which the driving mode setting part of hybrid ECU which concerns on the same embodiment performs. It is explanatory drawing which shows an example of transition of various state quantities in case the control by hybrid ECU which concerns on the same embodiment is performed when the 2nd motor generator locks in single motor EV driving mode. The processing in the twin motor EV travel mode after the travel mode is switched in response to the temperature of the second motor generator 24 exceeding the threshold value TH1 performed by the travel mode setting unit of the hybrid ECU according to the embodiment. It is a flowchart which shows an example of a flow. It is a schematic diagram which shows an example of schematic structure of the drive system of the hybrid vehicle which concerns on a modification.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

<1. Introduction>
The hybrid vehicle can be configured to be able to switch between a plurality of travel modes in which combinations of operating states of the engine and the motor are different from each other. In the hybrid vehicle, for example, an improvement in fuel consumption is realized by appropriately switching the traveling mode according to the traveling state. As one of such travel modes, a travel mode that travels by the output of the drive motor can be selected. Since the motor has an output characteristic capable of outputting a large torque at a low rotational speed as compared with the engine, for example, the traveling mode is selected in a state where the vehicle speed is relatively low.

  FIG. 1 is an explanatory diagram illustrating an example of changes in various state quantities in a case where control for compensating for a shortage of target torque is performed based on engine output when the drive motor is locked during the travel mode. . Specifically, FIG. 1 shows transitions of various state quantities for an example in which a motor generator that is a three-phase AC motor is applied as a drive motor. The motor generator has a function as a drive motor that is driven using electric power to generate a driving force of the vehicle, and a function as a generator that generates electric power using the kinetic energy of the drive wheels when the vehicle is decelerated.

  As shown in FIG. 1, when the brake is released and the accelerator is stepped on at time T2 during the travel mode in which the vehicle travels by the output of the drive motor, the target that is the target value of torque transmitted to the drive wheels. Torque starts to rise. Further, during the traveling mode, control is performed so that the target torque is output by the motor generator. Therefore, after time T2, the torque output from the motor generator increases as the target torque increases.

  When the motor generator is locked at time T2, the motor generator does not rotate, so that the vehicle speed does not increase after time T2, as shown in FIG. When the target torque finishes increasing at time T4, the motor generator continuously outputs a predetermined torque after time T4. As the torque is continuously output by the motor generator, the temperature of the motor generator continuously increases after time T4 as shown in FIG.

  Here, in order to prevent the motor generator from being heated excessively, it is conceivable to reduce the output of the motor when the temperature of the motor generator exceeds a predetermined temperature threshold. For example, as shown in FIG. 1, when the temperature of the motor generator exceeds a predetermined temperature threshold at time T6, control is performed so that the torque output by the motor generator decreases after time T6. At a later time T8, the torque output by the motor generator becomes zero. Further, as the torque output from the motor generator decreases, the temperature of the motor generator decreases after time T6.

  Further, when the output of the motor generator is reduced in this way, it is conceivable to compensate the shortage of the target torque by the engine output by starting the engine. For example, at time T6, the engine is started, and as shown in FIG. 1, the torque output from the engine and the engine speed increase after time T6. Thereby, after time T6, the shortage of the target torque due to the decrease in the output of the motor generator is compensated by the output of the engine.

  However, starting the engine during the travel mode in which the vehicle travels based on the output of the drive motor can be a factor that makes the driver feel uncomfortable. In particular, the engine is started even though the remaining capacity SOC (State Of Charge) of the battery is sufficient, so that the driver feels uncomfortable. Therefore, the present specification proposes a mechanism capable of compensating for the shortage of the target torque due to the decrease in the output of the drive motor without causing the driver to feel uncomfortable when the drive motor is locked.

<2. Drive System for Hybrid Vehicle According to Embodiment of the Present Invention>
First, the configuration of the drive system 1 and the various travel modes in the drive system 1 of the hybrid vehicle according to the embodiment of the present invention will be described.

[2-1. Constitution]
FIG. 2 is a schematic diagram illustrating an example of a schematic configuration of the drive system 1 of the hybrid vehicle according to the present embodiment. The drive system 1 includes an engine 10, a first motor generator (M / G1) 20, and a second motor generator (M / G2) 24. The engine 10, the first motor generator 20, and the second motor generator This is a power unit that can be used together with the motor generator 24 as a drive source. Specifically, the engine 10 can output a driving force for driving the driving wheels 80. Further, the first motor generator 20 and the second motor generator 24 can independently output a driving force for driving the driving wheels 80. In the drive system 1, vehicle driving force control is performed while switching between a single motor EV traveling mode, a twin motor EV traveling mode, an engine traveling mode, and a hybrid traveling mode.

  The single motor EV travel mode is a mode in which the vehicle is driven by the output of the second motor generator 24. The twin motor EV travel mode is a mode in which the vehicle is driven by the outputs of the first motor generator 20 and the second motor generator 24. The engine travel mode is a mode in which the vehicle is driven by the output of the engine 10. The hybrid travel mode is a mode in which the vehicle is driven by at least one of the outputs of the first motor generator 20 and the second motor generator 24 and the output of the engine 10.

  The engine 10 is an internal combustion engine that generates driving force using gasoline or the like as fuel, and has a crankshaft 11 as an output shaft. The crankshaft 11 extends in the automatic transmission 30. A gear type oil pump 15 is connected to the crankshaft 11. The oil pump 15 is driven by the driving force of the engine 10 or the rotation of the driving wheels 80 and supplies hydraulic oil to the automatic transmission 30. The hydraulic fluid supplied to the automatic transmission 30 is used as hydraulic fluid that operates the CVT 31 and each clutch. The automatic transmission 30 includes a first motor generator 20, a second motor generator 24, and a continuously variable transmission (CVT) 31 as an automatic transmission.

  In addition, the oil pump 15 is not shown with respect to the shaft (for example, the motor shaft 25 of the second motor generator 24) on the drive wheel 80 side of the second transmission clutch 46, the primary shaft 34 or the secondary shaft 36 of the CVT 31. It may be connected via a gear mechanism. When the oil pump 15 is connected to the shaft closer to the drive wheel 80 than the second transmission clutch 46, the oil pump 15 can be driven by the rotation of the drive wheel 80. When the oil pump 15 is connected to the primary shaft 34 or the secondary shaft 36, the oil pump 15 can also be driven by the rotation of the drive wheel 80 while the second transmission clutch 46 is engaged. When the oil pump 15 is coupled to the shaft closer to the drive wheel 80 than the second transmission clutch 46, the primary shaft 34 or the secondary shaft 36, the drive wheel 80 is coupled to the second transmission clutch 46 coupled to the oil pump 15. Of the side shaft, the primary shaft 34 or the secondary shaft 36, and the crankshaft 11, the crankshaft 11 is driven by the higher rotation.

  Engine 10 and first motor generator 20 are arranged in series via engine clutch 42. Between the crankshaft 11 of the engine 10 and the motor shaft 21 of the first motor generator 20, an engine clutch 42 that fastens or releases between the crankshaft 11 and the motor shaft 21 is provided. Power can be transmitted between the crankshaft 11 and the motor shaft 21 when the engine clutch 42 is in the engaged state.

  The first motor generator 20 is, for example, a three-phase AC motor, and is connected to the high voltage battery 50 via the inverter 70. The first motor generator 20 is driven using the power of the high-voltage battery 50 (powering drive) to generate a driving force of the vehicle, and is driven using the driving force of the engine 10 to generate power. And function as a generator. Further, the first motor generator 20 has a function as a starter motor that starts or stops the engine 10 and a function as a motor that rotationally drives an oil pump 28 connected to the motor shaft 21.

  When the first motor generator 20 is caused to function as a starter motor, a drive motor or a drive motor for the oil pump 28, the inverter 70 converts the DC power supplied from the high voltage battery 50 into AC power, and the first motor generator 20 is driven. When the first motor generator 20 is caused to function as a generator, the inverter 70 converts the AC power generated by the first motor generator 20 into DC power and charges the high voltage battery 50.

  As described above, in the drive system 1 according to the present embodiment, power is transmitted between the crankshaft 11 and the motor shaft 21 not by the torque converter but by the engine clutch 42. For this reason, when the first motor generator 20 is caused to function as a drive motor, the drive power from the first motor generator 20 is consumed by the engine 10 by completely separating the first motor generator 20 and the engine 10. Thus, a decrease in efficiency of the first motor generator 20 can be suppressed.

  A gear type oil pump 28 is connected to the motor shaft 21 of the first motor generator 20. The oil pump 28 is rotationally driven by the motor shaft 21 and supplies hydraulic oil to the CVT 31 and each clutch. The oil pump 28 is configured as an electric oil pump driven by the first motor generator 20. The motor shaft 21 of the first motor generator 20 is connected to the primary shaft 34 of the CVT 31 via the first transmission clutch 44. The first transmission clutch 44 fastens or releases between the motor shaft 21 and the primary shaft 34. Power can be transmitted between the motor shaft 21 and the primary shaft 34 when the first transmission clutch 44 is in the engaged state.

  The CVT 31 has a primary shaft 34 and a secondary shaft 36 disposed in parallel to the primary shaft 34. A primary pulley 33 is fixed to the primary shaft 34, and a secondary pulley 35 is fixed to the secondary shaft 36. A winding type power transmission member 37 made of a belt or a chain is wound around the primary pulley 33 and the secondary pulley 35. The CVT 31 changes the pulley ratio by changing the wrapping radius of the power transmission member 37 on the primary pulley 33 and the secondary pulley 35, so that the CVT 31 has an arbitrary gear ratio between the primary shaft 34 and the secondary shaft 36. Transmit the converted power.

  The secondary shaft 36 is connected to the motor shaft 25 of the second motor generator 24 via the second transmission clutch 46. The second transmission clutch 46 fastens or releases between the secondary shaft 36 and the motor shaft 25. When the second transmission clutch 46 is in the engaged state, power can be transmitted between the secondary shaft 36 and the motor shaft 25. The motor shaft 25 of the second motor generator 24 is connected to the driving wheel 80 via a reduction gear and a driving shaft (not shown), so that the driving force output via the motor shaft 25 can be transmitted to the driving wheel 80. ing. The motor shaft 25 may be connected to a differential gear (not shown), and the driving force may be distributed to the front wheels and the rear wheels.

  The second motor generator 24 is connected to the engine 10 via an engine clutch 42, a first transmission clutch 44, and a second transmission clutch 46. Similar to the first motor generator 20, the second motor generator 24 is a three-phase AC motor, and is connected to the high voltage battery 50 via the inverter 70. The second motor generator 24 is driven (powering drive) using the electric power of the high voltage battery 50 to generate a driving force of the vehicle, and uses the kinetic energy of the driving wheels 80 when the vehicle is decelerated. And function as a generator to generate electricity.

  When causing the second motor generator 24 to function as a drive motor, the inverter 70 converts the DC power supplied from the high voltage battery 50 into AC power, and drives the second motor generator 24. When the second motor generator 24 is caused to function as a generator, the inverter 70 converts the AC power generated by the second motor generator 24 into DC power and charges the high voltage battery 50. The rated output of the second motor generator 24 and the rated output of the first motor generator 20 may be the same or different.

  A low voltage battery 60 is connected via a DC / DC converter 55 to the high voltage battery 50 connected to the first motor generator 20 and the second motor generator 24 via the inverter 70. The high voltage battery 50 is a chargeable / dischargeable battery having a rated voltage of 200V, for example, and the low voltage battery 60 is a chargeable / dischargeable battery having a rated voltage of 12V, for example. The low voltage battery 60 is used as a main power source of a hybrid vehicle system. The DC / DC converter 55 steps down the voltage of the DC power of the high voltage battery 50 and supplies the charging power to the low voltage battery 60.

  In addition, the drive system 1 includes a first temperature sensor 91, a second temperature sensor 93, an accelerator opening sensor 95, a vehicle speed sensor 97, and a battery remaining capacity sensor 99. Each sensor detects various physical quantities and outputs detection results to the hybrid ECU 100. The detection result is used for processing performed by the hybrid ECU 100 described later.

  First temperature sensor 91 detects the temperature of first motor generator 20. Specifically, the first temperature sensor 91 may detect the temperature of the coil of the first motor generator 20 as the temperature of the first motor generator 20.

  Second temperature sensor 93 detects the temperature of second motor generator 24. Specifically, the second temperature sensor 93 may detect the temperature of the coil of the second motor generator 24 as the temperature of the second motor generator 24.

  The accelerator opening sensor 95, the vehicle speed sensor 97, and the battery remaining capacity sensor 99 detect the accelerator opening, the vehicle speed, and the remaining capacity SOC of the high-voltage battery 50, respectively.

  The engine 10 is controlled by an engine control unit (engine ECU) 200. The automatic transmission 30 is controlled by a transmission control unit (transmission ECU) 300. The first motor generator 20 and the second motor generator 24 are controlled by a motor control unit (motor ECU) 400. These engine ECU 200, transmission ECU 300, and motor ECU 400 are connected to a hybrid control unit (hybrid ECU) 100 that controls the entire system in an integrated manner. The hybrid ECU 100 uses the engine ECU 200, the transmission ECU 300, the motor ECU 400, and the like to perform vehicle travel control or deceleration control, or charge control of the high-voltage battery 50. The hybrid ECU 100 is an example of a control device for a hybrid vehicle according to the present invention.

  Each ECU includes a microcomputer and various interfaces or peripheral devices. Each ECU is connected to be capable of bidirectional communication via a communication line such as a CAN (Controller Area Network), for example, and communicates control information and various types of information related to the controlled object.

  Specifically, each ECU is a CPU (Central Processing Unit) that is an arithmetic processing unit, a ROM (Read Only Memory) that is a storage element that stores programs used by the CPU, operational parameters, and the like, and is used in the execution of the CPU. It is composed of a program, a RAM (Random Access Memory) that temporarily stores parameters that change as appropriate during execution thereof, and the like. Each ECU may communicate with each sensor using CAN communication. Note that the functions of each ECU according to the present embodiment may be divided by a plurality of control devices. In this case, the plurality of control devices may be connected to each other via a communication line such as CAN. Hereinafter, the outline of the function of each ECU will be described.

  The engine ECU 200 receives a control command from the hybrid ECU 100 and calculates control amounts such as a throttle opening, an ignition timing, and a fuel injection amount based on information detected by various sensors provided in the engine 10. The engine ECU 200 drives the throttle valve, spark plug, fuel injection valve, and the like based on the calculated control amount, and controls the engine 10 so that the output of the engine 10 becomes a control command value. For example, a torque command value of the engine 10 is input to the engine ECU 200 as a control command from the hybrid ECU 100. Then, engine ECU 200 controls engine 10 such that the torque output by engine 10 becomes the command value.

  Motor ECU 400 receives a control command from hybrid ECU 100 and controls first motor generator 20 and second motor generator 24 via inverter 70, respectively. The motor ECU 400 outputs a current command and a voltage command to the inverter 70 based on information such as the rotation speed, voltage, and current of each of the first motor generator 20 and the second motor generator 24, and the first motor generator 20 The first motor generator 20 and the second motor generator 24 are controlled so that the outputs of the generator 20 and the second motor generator 24 become control command values. For example, as a control command from hybrid ECU 100, command values for the torques of first motor generator 20 and second motor generator 24 are input to motor ECU 400. Then, the motor ECU 400 controls the first motor generator 20 and the second motor generator 24 so that the torques output by the first motor generator 20 and the second motor generator 24 respectively become the command values. .

  The transmission ECU 300 receives the control command from the hybrid ECU 100, determines the gear ratio of the CVT 31, and controls the gear ratio to an appropriate gear ratio according to the driving state. The transmission ECU 300 controls the gear ratio of the CVT 31 by controlling the hydraulic pressure and adjusting the pulley ratio, for example. Further, the transmission ECU 300 receives a control command from the hybrid ECU 100 and controls the engine clutch 42, the first transmission clutch 44, the second transmission clutch 46, and the like according to the switching of the travel mode. The transmission ECU 300 controls connection / disconnection of each clutch by controlling the hydraulic pressure of the hydraulic oil of each clutch, for example. Specifically, information indicating the connection / disconnection state of each clutch is input to transmission ECU 300 as a control command from hybrid ECU 100. Then, the transmission ECU 300 controls the hydraulic pressure of the hydraulic oil of each clutch so that the connection / disconnection state of each clutch becomes a state corresponding to the control command.

[2-2. Driving mode]
Subsequently, with reference to FIGS. 3 to 6, the control by each ECU in various travel modes in the drive system 1 according to the present embodiment will be described in more detail. 3-6 is explanatory drawing for demonstrating each about the single motor EV driving mode in the drive system 1 which concerns on this embodiment, the twin motor EV driving mode, the engine driving mode, and the hybrid driving mode. 3 to 6, the broken line indicates the flow of electric power, and the alternate long and short dash line indicates the flow of power.

(Single motor EV running mode)
As shown in FIG. 3, in the single motor EV travel mode, transmission ECU 300 releases all of engine clutch 42, first transmission clutch 44, and second transmission clutch 46. In addition, motor ECU 400 drives second motor generator 24 via inverter 70 to output torque. Thereby, as shown in FIG. 3, electric power is supplied from the high voltage battery 50 to the second motor generator 24 via the inverter 70. Then, the torque output from the second motor generator 24 is transmitted to the drive wheels 80 as a drive force for driving the drive wheels 80.

(Twin motor EV running mode)
As shown in FIG. 4, in the twin motor EV traveling mode, the transmission ECU 300 opens the engine clutch 42 and fastens the first transmission clutch 44 and the second transmission clutch 46. The motor ECU 400 drives the first motor generator 20 and the second motor generator 24 via the inverter 70 to output torque. As a result, as shown in FIG. 4, power is supplied from the high voltage battery 50 to the first motor generator 20 and the second motor generator 24 via the inverter 70. The torque output from the first motor generator 20 is transmitted to the motor shaft 25 via the CVT 31 and is combined with the torque output from the second motor generator 24 to drive the drive wheels 80. It is transmitted to the drive wheel 80 as force.

(Engine driving mode)
As shown in FIG. 5, in the engine running mode, transmission ECU 300 engages all of engine clutch 42, first transmission clutch 44, and second transmission clutch 46. Engine ECU 200 drives engine 10 to output torque. As a result, as shown in FIG. 5, the torque output from the engine 10 is transmitted to the drive wheel 80 via the CVT 31 as a drive force for driving the drive wheel 80. The engine running mode is selected when each motor generator is malfunctioning or when the remaining capacity SOC of the high voltage battery 50 is insufficient, for example, when normal operation is not possible.

(Hybrid driving mode)
As shown in FIG. 6, in the hybrid travel mode, transmission ECU 300 engages all of engine clutch 42, first transmission clutch 44, and second transmission clutch 46. Engine ECU 200 drives engine 10 to output torque. The motor ECU 400 drives at least one of the first motor generator 20 and the second motor generator 24 via the inverter 70 to output torque. Thereby, as shown in FIG. 6, the torque output from the engine 10 is transmitted to the motor shaft 25 via the CVT 31, and from at least one of the first motor generator 20 and the second motor generator 24. Together with the output torque, it is transmitted to the drive wheel 80 as a drive force for driving the drive wheel 80.

  Furthermore, when starting the engine 10, the transmission ECU 300 fastens the engine clutch 42. Motor ECU 400 drives first motor generator 20 via inverter 70 and cranks engine 10 by the driving force of first motor generator 20. At this time, the transmission ECU 300 opens the first transmission clutch 44 before the engine clutch 42 is engaged so that the longitudinal vibration of the vehicle does not occur due to the differential rotation between the engine 10 and the first motor generator 20.

  The drive system 1 according to the present embodiment can generate electric power by causing the second motor generator 24 to regenerate the kinetic energy of the drive wheels 80 during deceleration of the vehicle in all the travel modes. In the twin motor EV travel mode, the engine travel mode, and the hybrid travel mode, power can be generated by causing the first motor generator 20 to regenerate the kinetic energy of the drive wheels 80 when the vehicle decelerates. Further, in the single motor EV traveling mode and the hybrid traveling mode, the first motor generator 20 can generate electric power using a part or all of the driving force from the engine 10. Further, in the engine running mode, the first motor generator 20 can generate electric power by a part of the driving force from the engine 10.

  In the drive system 1 according to the present embodiment, the first motor generator 20 has a function as a starter motor of the engine 10. Therefore, the conventional starter motor used only when the engine 10 is started or stopped can be omitted. The first motor generator 20 is integrated with the oil pump 28 and functions as an electric oil pump. Therefore, the conventional electric oil pump that has been used only when the engine 10 or the driving wheel 80 is stopped and the hydraulic pressure cannot be generated by the gear-type oil pump 15 can be omitted.

  In the drive system 1 according to the present embodiment, the first motor generator 20 is connected to the primary pulley 33 of the CVT 31 via the first transmission clutch 44, and the first motor generator 20 is running while traveling. The generator 20 can function as a drive motor. Therefore, the power performance of the vehicle can be improved. Furthermore, while the driving force of the vehicle is generated by the engine 10, the first motor generator 20 can function as a generator when there is an excessive driving force in the output of the engine 10. Therefore, the fuel consumption performance of the vehicle can be improved.

  According to the present embodiment, the control related to the switching of the driving mode performed by the hybrid ECU 100 compensates for the shortage of the target torque due to the decrease in the output of the drive motor without causing the driver to feel strange when the drive motor is locked. It becomes possible to do.

<3. Functional configuration of hybrid ECU>
Subsequently, a functional configuration of the hybrid ECU 100 according to the present embodiment will be described with reference to FIGS. 7 and 8.

  FIG. 7 is an explanatory diagram showing an example of a functional configuration of the hybrid ECU 100 according to the present embodiment. As shown in FIG. 7, the hybrid ECU 100 includes a travel mode setting unit 102, a first motor torque calculation unit 104, a first output restriction unit 106, a second motor torque calculation unit 108, and a second motor torque calculation unit 104. Output limiting unit 110, engine torque calculating unit 112, and clutch state setting unit 114.

[3-1. Driving mode setting section]
The traveling mode setting unit 102 sets the traveling mode of the vehicle according to the traveling state. In addition, the travel mode setting unit 102 provides information indicating the currently set travel mode as a first motor torque calculation unit 104, a second motor torque calculation unit 108, an engine torque calculation unit 112, and a clutch state setting unit. To 114. Note that the travel mode setting unit 102 includes information about the travel mode switching, such as the determination result regarding the travel mode switching and the travel mode switching history, as the first motor torque calculation unit 104 and the second motor torque calculation unit. 108, and may be output to the engine torque calculation unit 112 and the clutch state setting unit 114.

  The traveling mode setting unit 102 sets the traveling mode of the vehicle based on, for example, the accelerator opening, the vehicle speed, the remaining capacity SOC of the high-voltage battery 50, and the like in a normal time when the second motor generator 24 is not locked. It may be set. Moreover, the driving mode setting unit 102 may set the driving mode of the vehicle so as to improve fuel efficiency.

  Hereinafter, when the second motor generator 24 is locked, which is performed by the travel mode setting unit 102 according to the present embodiment, the shortage of the target torque due to the decrease in the output of the drive motor is compensated without causing the driver to feel uncomfortable. A description will be given of the switching of the travel mode for the purpose.

  The travel mode setting unit 102 according to the present embodiment performs the case where the temperature of the second motor generator 24 exceeds the threshold during the first travel mode in which the driving wheels 80 are driven by the output of the second motor generator 24. Then, at least the output of the first motor generator 20 is used to switch to the second traveling mode in which the driving wheels 80 are driven. Specifically, traveling mode setting unit 102 switches to twin motor EV traveling mode when the temperature of second motor generator 24 exceeds threshold value TH1 during single motor EV traveling mode. The threshold value TH1 is appropriately set to a value that can determine whether or not the second motor generator 24 is in a state of being continuously heated due to being locked.

  Here, the single motor EV travel mode corresponds to an example of the first travel mode. The twin motor EV travel mode after the travel mode is switched in response to the temperature of the second motor generator 24 exceeding the threshold value TH1 corresponds to an example of the second travel mode. The second traveling mode may include a traveling mode in which the driving power is not output from the second motor generator 24 and the driving wheels 80 are driven by the first motor generator 20.

  According to this embodiment, when the temperature of the second motor generator 24 exceeds the threshold value TH1 during the single motor EV travel mode, the mode is switched to the twin motor EV travel mode. Thereby, when the second motor generator 24 is locked, the driving force for driving the driving wheels 80 can be output to the first motor generator 20. Therefore, when the second motor generator 24 is locked, the shortage of the target torque due to the decrease in the output of the second motor generator 24 can be compensated without starting the engine 10. Therefore, when the second motor generator 24 is locked, the driver does not feel uncomfortable due to the engine starting even though the remaining capacity SOC is sufficient, and the output of the second motor generator 24 is reduced. It becomes possible to compensate for the shortage of the target torque.

  As will be described later, when the temperature of the second motor generator 24 exceeds the limit temperature, the output of the second motor generator 24 is limited by the second output limiter 110. The threshold value TH1 may be set to the limit temperature, for example. The limit temperature is set in accordance with the type and performance of the second motor generator 24, and is a temperature for determining whether or not a high temperature state in which the second motor generator 24 may be damaged has occurred. By setting the threshold value TH1 to the limit temperature, when the output of the second motor generator 24 is limited, the shortage of the target torque can be compensated by the output of the first motor generator 20. The temperature limit for the first motor generator 20 and the temperature limit for the second motor generator 24 may be set to the same value or different values.

  Further, the threshold value TH1 may be set to a temperature lower than the limit temperature. By setting the threshold value TH1 to a temperature lower than the limit temperature, the switching to the twin motor EV travel mode can be performed at a time before the output of the second motor generator 24 is limited. Thereby, the output of the second motor generator 24 can be reduced at a time before the output of the second motor generator 24 is limited. Therefore, it can be suppressed that the temperature of the second motor generator 24 reaches the limit temperature and the output of the second motor generator 24 is limited.

  The traveling mode setting unit 102 determines whether or not the second motor generator 24 may be locked prior to determining whether or not the temperature of the second motor generator 24 exceeds the threshold value TH1. The determination based on the threshold value TH1 may be performed according to the determination result. For example, the travel mode setting unit 102 determines that the second motor is satisfied when the accelerator opening is greater than or equal to a predetermined opening, the vehicle speed is lower than the predetermined speed, and the brake is OFF. It is determined that the generator 24 may be locked. The predetermined opening and the predetermined speed are appropriately set to values that can determine whether or not the second motor generator 24 may be locked, depending on various design specifications of the vehicle. The

  When it is determined that there is a possibility that the second motor generator 24 is locked, the traveling mode setting unit 102 determines whether or not the temperature of the second motor generator 24 exceeds the threshold value TH1. On the other hand, when it is not determined that the second motor generator 24 may be locked, the traveling mode setting unit 102 determines whether the temperature of the second motor generator 24 has exceeded the threshold value TH1. It does not have to be done.

  The travel mode setting unit 102 is configured such that, when the temperature of the second motor generator 24 exceeds the threshold value TH1 during the single motor EV travel mode, the temperature of the first motor generator 20 is lower than a predetermined temperature, and When the remaining capacity SOC of the high voltage battery 50 that is a battery that supplies power to one motor generator 20 is equal to or greater than a predetermined remaining capacity, the mode may be switched to the twin motor EV travel mode. The predetermined temperature is set to a temperature at which it can be determined whether or not the temperature of the first motor generator 20 has decreased to such an extent that the target torque can be output by the first motor generator 20. Further, the predetermined remaining capacity is set to a value that can determine whether or not the high-voltage battery 50 is charged with electric power to the extent that the first motor generator 20 can output the target torque.

  On the other hand, the travel mode setting unit 102 is configured such that the temperature of the first motor generator 20 is not lower than a predetermined temperature, or the remaining capacity SOC of the high voltage battery 50 that supplies power to the first motor generator 20 is a predetermined remaining When the capacity is not more than the capacity, the engine travel mode or the hybrid travel mode may be switched. Thereby, even if the target torque cannot be output by the first motor generator 20 when the second motor generator 24 is locked, the shortage of the target torque due to the decrease in the output of the drive motor is reduced to the engine. It can be compensated by 10 outputs.

  Traveling mode setting unit 102 is in a case where a predetermined condition is satisfied in the twin motor EV traveling mode after the traveling mode is switched in response to the temperature of second motor generator 24 exceeding threshold value TH1. The mode may be switched to the single motor EV running mode.

  For example, the traveling mode setting unit 102 may switch to the single motor EV traveling mode when the temperature of the second motor generator 24 falls below a predetermined temperature during the twin motor EV traveling mode. It is determined whether or not the predetermined temperature has decreased to such an extent that the target torque can be output by the second motor generator 24 after the temperature of the second motor generator 24 has increased due to locking. Is set to a possible temperature. Thereby, after the second motor generator 24 is locked, when it becomes possible to output the target torque by the second motor generator 24, it is possible to switch to the single motor EV travel mode.

  In addition, travel mode setting unit 102 may switch to single motor EV travel mode when the temperature of first motor generator 20 exceeds threshold value TH2 during the twin motor EV travel mode. The threshold value TH2 can be appropriately set to a value that can determine whether or not the first motor generator 20 is in a state of being continuously heated due to being locked. Thus, after the second motor generator 24 is locked, when the first motor generator 20 is further locked, the driving force for driving the driving wheels 80 can be output to the second motor generator 24. it can. Therefore, the target torque can be continuously output by the first motor generator 20 and the second motor generator 24 without starting the engine 10.

  As will be described later, when the temperature of the first motor generator 20 exceeds the limit temperature, the output of the first motor generator 20 is limited by the first output limiter 106. The threshold value TH2 may be set to the limit temperature, for example. The limit temperature is set in accordance with the type and performance of the first motor generator 20, and is a temperature for determining whether or not a high temperature state in which the first motor generator 20 may be damaged is generated. By setting the threshold value TH2 to the limit temperature, when the output of the first motor generator 20 is limited, the shortage of the target torque can be compensated by the output of the second motor generator 24.

  The threshold value TH2 may be set to a temperature lower than the limit temperature. By setting the threshold value TH2 to a temperature lower than the limit temperature, the output of the first motor generator 20 can be reduced at a time before the output of the first motor generator 20 is limited. Therefore, it can be suppressed that the temperature of first motor generator 20 reaches the limit temperature and the output of first motor generator 20 is limited.

[3-2. First motor torque calculation unit]
First motor torque calculation unit 104 calculates a first torque command value, which is a torque command value of first motor generator 20, and outputs the first torque command value to motor ECU 400. Thereby, the motor ECU 400 controls the first motor generator 20 so that the torque output by the first motor generator 20 becomes the first torque command value.

  The first motor torque calculation unit 104 calculates a first torque command value based on the travel mode set by the travel mode setting unit 102. For example, in the single motor EV travel mode, the engine travel mode, and the hybrid travel mode, the first motor torque calculation unit 104 calculates 0 as the first torque command value. In the twin motor EV travel mode, the first motor torque calculation unit 104 sets the target of the sum of the first torque command value and the second torque command value that is the torque command value of the second motor generator 24. A first torque command value is calculated so as to be torque.

  The target torque is calculated by the hybrid ECU 100 based on, for example, the accelerator opening and the vehicle speed. In addition, the first torque command value, the second torque command value, and the engine torque command value that is the command value of the engine torque are the first motor torque calculation unit 104, the second motor torque calculation unit 108, and the engine torque. The calculation unit 112 can calculate the values in cooperation.

  The first motor torque calculation unit 104 generates a second torque command from the target torque when switching to the twin motor EV travel mode is performed in response to the temperature of the second motor generator 24 exceeding the threshold value TH1. A value obtained by subtracting the value may be calculated as the first torque command value. Thereby, when the second motor generator 24 is locked, the shortage of the target torque due to the decrease in the output of the second motor generator 24 can be compensated more appropriately by the output of the first motor generator 20. it can.

  Further, the second torque command value may be output from the second motor torque calculation unit 108 to the first motor torque calculation unit 104, for example. In this case, the first motor torque calculation unit 104 The first torque command value can be calculated using the second torque command value output from the second motor torque calculation unit 108.

  In addition, the first motor torque calculation unit 104 performs the first motor during the twin motor EV travel mode after the travel mode is switched in response to the temperature of the second motor generator 24 exceeding the threshold value TH1. The first torque command value may be decreased when the temperature of the generator 20 exceeds the threshold value TH2. Thereby, after the second motor generator 24 is locked, the electric power supplied to the first motor generator 20 can be reduced when the first motor generator 20 is further locked. Therefore, excessive heating of first motor generator 20 can be prevented.

  The first motor torque calculation unit 104 determines the first torque command value based on the operation command from the first output limiting unit 106 when the temperature of the first motor generator 20 exceeds the limit temperature. Decrease.

[3-3. First output limiting unit]
The first output limiter 106 limits the output of the first motor generator 20 when the temperature of the first motor generator 20 exceeds the limit temperature. Specifically, the first output restriction unit 106 outputs an operation command to the first motor torque calculation unit 104 when the temperature of the first motor generator 20 exceeds the restriction temperature, thereby The output of the motor generator 20 is reduced. As a result, the power supplied to the first motor generator 20 is reduced by reducing the output of the first motor generator 20 when there is a high temperature state in which the first motor generator 20 may be damaged. Can be made. Therefore, damage to the first motor generator 20 can be prevented.

[3-4. Second motor torque calculation unit]
Second motor torque calculation unit 108 calculates a second torque command value, which is a torque command value of second motor generator 24, and outputs the second torque command value to motor ECU 400. Thereby, the motor ECU 400 controls the second motor generator 24 so that the torque output by the second motor generator 24 becomes the second torque command value.

  Further, the second motor torque calculation unit 108 calculates a second torque command value based on the travel mode set by the travel mode setting unit 102. For example, in the single motor EV travel mode, the second motor torque calculation unit 108 calculates the second torque command value so as to match the target torque. In the twin motor EV running mode, the second motor torque calculation unit 108 calculates the second torque command value so that the sum of the first torque command value and the second torque command value becomes the target torque. To do. In the engine travel mode, the second motor torque calculation unit 108 calculates 0 as the second torque command value. In the hybrid travel mode, the second motor torque calculation unit 108 calculates the second torque command value so that the sum of the second torque command value and the engine torque command value becomes the target torque.

  The second motor torque calculation unit 108 decreases the second torque command value when switching to the twin motor EV running mode is performed in response to the temperature of the second motor generator 24 exceeding the threshold value TH1. You may let them. Thereby, when the second motor generator 24 is locked, the electric power supplied to the second motor generator 24 can be reduced. Therefore, it is possible to prevent the second motor generator 24 from being heated excessively.

  In addition, the second motor torque calculation unit 108 receives the second torque command value when switching to the twin motor EV travel mode is performed in response to the temperature of the second motor generator 24 exceeding the threshold value TH1. The second torque command value may be decreased so that the value approaches a predetermined value. The predetermined value is the torque output by the second motor generator 24 when the switching to the twin motor EV running mode is performed in response to the temperature of the second motor generator 24 exceeding the threshold value TH1. Corresponds to the second motor generator target torque. The second motor generator target torque can be lowered to the extent that the second motor generator 24 can output the target torque after the temperature of the second motor generator 24 rises due to the locking. Set to a value.

  The second motor torque calculation unit 108 may calculate the second motor generator target torque based on the temperature of the second motor generator 24 at the time when the switching to the twin motor EV travel mode is performed. For example, the second motor torque calculator 108 may calculate the second motor generator target torque using the map M10 shown in FIG. Map M10 represents the relationship between the temperature of second motor generator 24 and the second motor generator target torque at the time when switching to the twin motor EV travel mode is performed. Specifically, as shown in FIG. 8, the second motor generator target torque becomes smaller as the temperature of the second motor generator 24 is higher at the time when switching to the twin motor EV travel mode is performed. May be set.

  Note that the second motor torque calculation unit 108 may decrease the second torque command value so that the second torque command value approaches 0 when switching to the second travel mode is performed. . The second traveling mode corresponds to a traveling mode in which no driving force is output from the second motor generator 24 and the driving wheels 80 are driven by the first motor generator 20. Further, the second motor torque calculation unit 108 determines the second torque command value based on the operation command from the second output limit unit 110 when the temperature of the second motor generator 24 exceeds the limit temperature. Decrease.

  In addition, the second motor torque calculation unit 108 performs the first motor during the twin motor EV travel mode after the travel mode is switched in response to the temperature of the second motor generator 24 exceeding the threshold value TH1. When the temperature of the generator 20 exceeds the threshold value TH2, a value obtained by subtracting the first torque command value from the target torque may be calculated as the second torque command value. Thereby, after the second motor generator 24 is locked, when the first motor generator 20 is further locked, the shortage of the target torque due to the decrease in the output of the first motor generator 20 is reduced to the second motor generator 20. The output of the generator 24 can compensate more appropriately.

  In addition, the first torque command value may be output from the first motor torque calculation unit 104 to the second motor torque calculation unit 108, for example. In this case, the second motor torque calculation unit 108 The second torque command value can be calculated using the first torque command value output from the first motor torque calculation unit 104.

[3-5. Second output limiting unit]
The second output limiting unit 110 is an example of an output limiting unit according to the present invention that limits the output of the second motor generator 24 when the temperature of the second motor generator 24 exceeds the limiting temperature. Specifically, the second output restriction unit 110 outputs an operation command to the second motor torque calculation unit 108 when the temperature of the second motor generator 24 exceeds the restriction temperature, thereby The output of the motor generator 24 is decreased. As a result, the power supplied to the second motor generator 24 is reduced by lowering the output of the second motor generator 24 when a high temperature state in which the second motor generator 24 may be damaged occurs. Can be made. Therefore, damage to the second motor generator 24 can be prevented.

[3-6. Engine torque calculation unit]
Engine torque calculation unit 112 calculates an engine torque command value, which is a torque command value of engine 10, and outputs it to engine ECU 200. Thereby, engine ECU 200 controls engine 10 so that the torque output by engine 10 becomes the engine torque command value.

  Further, the engine torque calculation unit 112 calculates an engine torque command value based on the travel mode set by the travel mode setting unit 102. For example, in the single motor EV travel mode and the twin motor EV travel mode, the engine torque calculation unit 112 calculates 0 as the engine torque command value. In the engine travel mode, the engine torque calculation unit 112 calculates the engine torque command value so as to coincide with the target torque. In the hybrid travel mode, the engine torque calculation unit 112 calculates the engine torque command value so that the sum of the second torque command value and the engine torque command value becomes the target torque.

[3-7. Clutch state setting section]
Clutch state setting unit 114 sets the connection / disconnection state of each clutch, and outputs information indicating the connection / disconnection state of each clutch to transmission ECU 300 as a control command. Thereby, the hydraulic pressure of the hydraulic oil of each clutch is controlled by transmission ECU 300 so that the connection / disconnection state of each clutch becomes a state corresponding to the control command.

  Further, the clutch state setting unit 114 sets the connection / disconnection state of each clutch based on the travel mode set by the travel mode setting unit 102. For example, in the single motor EV travel mode, the clutch state setting unit 114 sets the state in which the engine clutch 42, the first transmission clutch 44, and the second transmission clutch 46 are all released as the connection / disconnection state of each clutch. . In the twin motor EV travel mode, the clutch state setting unit 114 sets the state where the engine clutch 42 is released and the first transmission clutch 44 and the second transmission clutch 46 are engaged as the connection / disconnection state of each clutch. Set. Further, in the engine travel mode and the hybrid travel mode, the clutch state setting unit 114 sets the state where all of the engine clutch 42, the first transmission clutch 44, and the second transmission clutch 46 are engaged as the connection / disconnection state of each clutch. Set.

<4. Operation>
Subsequently, a flow of processing performed by the hybrid ECU 100 according to the present embodiment will be described with reference to FIGS.

  FIG. 9 is a flowchart illustrating an example of a flow of processing during the single motor EV travel mode performed by the travel mode setting unit 102 of the hybrid ECU 100 according to the present embodiment. The process shown in FIG. 9 is executed in a state where the single motor EV travel mode is set as the travel mode of the vehicle.

  As shown in FIG. 9, first, the traveling mode setting unit 102 determines whether or not there is a possibility that the second motor generator 24 is locked. Specifically, the traveling mode setting unit 102 determines whether or not all the conditions that the accelerator opening is equal to or greater than a predetermined opening, the vehicle speed is lower than the predetermined speed, and the brake is OFF are satisfied. Accordingly, it is determined whether or not there is a possibility that the second motor generator 24 is locked (step S502).

  When at least one of the accelerator opening is equal to or larger than the predetermined opening, the vehicle speed is lower than the predetermined speed, and the brake is OFF is not satisfied (step S502 / NO), the traveling mode setting unit 102 determines that there is no possibility that the second motor generator 24 is locked, and the process shown in FIG. 9 ends. On the other hand, when the accelerator opening is equal to or greater than the predetermined opening, the vehicle speed is lower than the predetermined speed, and the brake is OFF (step S502 / YES), the traveling mode setting unit 102 Then, it is determined that there is a possibility that the second motor generator 24 is locked, and the process proceeds to step S504.

  In step S504, traveling mode setting unit 102 determines whether or not the temperature of second motor generator 24 exceeds threshold value TH1 (step S504). When it is not determined that the temperature of the second motor generator 24 has exceeded the threshold value TH1 (step S504 / NO), the processing illustrated in FIG. 9 ends. On the other hand, when it is determined that the temperature of second motor generator 24 exceeds threshold value TH1 (step S504 / YES), traveling mode setting unit 102 determines that the temperature of first motor generator 20 is lower than a predetermined temperature, and Then, it is determined whether or not the remaining capacity SOC of the high voltage battery 50 is equal to or greater than a predetermined remaining capacity (step S506).

  When it is determined that the temperature of first motor generator 20 is lower than the predetermined temperature and the remaining capacity SOC of high voltage battery 50 is equal to or greater than the predetermined remaining capacity (step S506 / YES), travel mode setting unit 102 Switches to the twin motor EV running mode (step S508), and the process shown in FIG. 9 ends. On the other hand, when it is determined that the temperature of first motor generator 20 is not lower than the predetermined temperature or the remaining capacity SOC of high voltage battery 50 is not equal to or higher than the predetermined remaining capacity (step S506 / NO), the travel mode setting is performed. The unit 102 switches to the engine travel mode or the hybrid travel mode (step S510), and the process illustrated in FIG. 9 ends.

  FIG. 10 is an explanatory diagram showing an example of changes in various state quantities when the control by the hybrid ECU 100 according to the present embodiment is performed when the second motor generator 24 is locked during the single motor EV travel mode. It is. As shown in FIG. 10, when the brake is released and the accelerator is stepped on at time T <b> 12 during the single motor EV traveling mode that travels based on the output of the second motor generator 24, it is transmitted to the drive wheels 80. The target torque that is the target value of torque starts to increase. Further, in the single motor EV travel mode, the second torque command value, which is the torque command value of the second motor generator 24, is calculated by the second motor torque calculation unit 108 so as to coincide with the target torque. . Therefore, after time T12, the torque output by the second motor generator 24 increases as the target torque increases.

  When the second motor generator 24 is locked at time T12, the second motor generator 24 does not rotate, so that the vehicle speed does not increase after time T12 as shown in FIG. When the target torque finishes increasing at time T14, the second motor generator 24 continuously outputs a predetermined torque after time T14. As the torque is continuously output by the second motor generator 24, as shown in FIG. 10, the temperature of the second motor generator 24 continuously increases after time T14.

  As shown in FIG. 10, when the temperature of the second motor generator 24 exceeds the threshold value TH1 at time T16, the travel mode setting unit 102 according to the present embodiment switches to the twin motor EV travel mode. . At time T16, the fact that the accelerator opening is equal to or greater than the predetermined opening, the vehicle speed is lower than the predetermined speed, and the brake is OFF is satisfied, and further, the first motor generator It is assumed that the temperature 20 is lower than the predetermined temperature, and the remaining capacity SOC of the high voltage battery 50 is equal to or higher than the predetermined remaining capacity.

  Then, after time T16, the second motor torque calculation unit 108 determines that the second torque command value is the second motor generator target, for example, in order to prevent the second motor generator 24 from being heated excessively. The second torque command value is decreased so as to approach the torque. As a result, as shown in FIG. 10, the torque output by the second motor generator 24 decreases after time T16, and reaches the second motor generator target torque at time T18 after time T16. . Further, as the torque output from the second motor generator 24 decreases, the temperature of the second motor generator 24 decreases after time T16.

  In addition, after time T16, the first motor torque calculation unit 104 uses, for example, a value obtained by subtracting the second torque command value from the target torque as the torque command value of the first motor generator 20. Calculated as one torque command value. Thereby, as shown in FIG. 10, the torque output by first motor generator 20 increases after time T16. Therefore, after time T16, the shortage of the target torque due to the decrease in the output of the second motor generator 24 can be compensated by the output of the first motor generator 20.

  Furthermore, according to the present embodiment, the engine 10 does not start at time T16, so that the torque output from the engine 10 and the engine speed do not increase after time T16 as shown in FIG. Therefore, when the second motor generator 24 is locked, it is possible to compensate for the shortage of the target torque due to the decrease in the output of the second motor generator 24 without giving the driver a sense of incongruity.

  FIG. 11 shows the twin motor EV travel after the travel mode is switched in response to the temperature of the second motor generator 24 exceeding the threshold value TH1 performed by the travel mode setting unit 102 of the hybrid ECU 100 according to the present embodiment. It is a flowchart which shows an example of the flow of the process in mode.

  As shown in FIG. 11, first, traveling mode setting unit 102 determines whether or not the temperature of first motor generator 20 exceeds threshold value TH2 (step S702). If it is not determined that the temperature of first motor generator 20 has exceeded threshold value TH2 (step S702 / NO), the processing shown in FIG. 11 ends. On the other hand, when it is determined that the temperature of first motor generator 20 has exceeded threshold value TH2 (step S702 / YES), traveling mode setting unit 102 determines whether the temperature of second motor generator 24 has fallen below a predetermined temperature. Is determined (step S704).

  When it is determined that the temperature of the second motor generator 24 has fallen below the predetermined temperature (step S704 / YES), the travel mode setting unit 102 switches to the single motor EV travel mode (step S706), and FIG. The process shown in FIG. On the other hand, when it is not determined that the temperature of the second motor generator 24 is lower than the predetermined temperature (step S704 / NO), the travel mode setting unit 102 does not switch to the single motor EV travel mode, and FIG. The process shown ends.

  In the process flow shown in FIG. 11, the order of the determination process in step S702 and the determination process in step S704 may be reversed, and either the determination process in step S702 or the determination process in step S704 is omitted. May be.

<5. Modification>
In the drive system 1 described above, the motor shaft 25 of the second motor generator 24 is connected to the secondary shaft 36 via the second transmission clutch 46, but the arrangement of the second motor generator 24 is related. It is not limited to examples. Hereinafter, the drive system 2 according to a modified example in which the arrangement of the second motor generator 24 is different from that of the drive system 1 will be described.

  FIG. 12 is a schematic diagram illustrating an example of a schematic configuration of the drive system 2 of the hybrid vehicle according to the modification. In the drive system 2 according to the modification, the arrangement of the second motor generator 24 is different from that of the drive system 1 described with reference to FIG. Further, unlike the drive system 1, the drive system 2 according to the modification does not include the second transmission clutch 46. As shown in FIG. 12, in the modification, the motor shaft 25 of the second motor generator 24 is connected to the primary shaft 34, and the driving force output via the motor shaft 25 can be transmitted to the primary shaft 34. It has become. The secondary shaft 36 is connected to the drive wheel 80 via a reduction gear and a drive shaft (not shown) so that the driving force output through the secondary shaft 36 can be transmitted to the drive wheel 80. Hereinafter, various traveling modes in the drive system 2 according to the modification will be described.

  In the modification, in the single motor EV travel mode, the transmission ECU 300 opens the engine clutch 42 and the first transmission clutch 44. In addition, motor ECU 400 drives second motor generator 24 via inverter 70 to output torque. Thereby, electric power is supplied from the high voltage battery 50 to the second motor generator 24 via the inverter 70. The torque output from the second motor generator 24 is transmitted to the secondary shaft 36 via the CVT 31 and is transmitted to the drive wheels 80 as a drive force for driving the drive wheels 80.

  In the modification, in the twin motor EV traveling mode, the transmission ECU 300 releases the engine clutch 42 and fastens the first transmission clutch 44. The motor ECU 400 drives the first motor generator 20 and the second motor generator 24 via the inverter 70 to output torque. Thereby, electric power is supplied from the high voltage battery 50 to the first motor generator 20 and the second motor generator 24 via the inverter 70. The torque output from the first motor generator 20 and the second motor generator 24 is transmitted to the secondary shaft 36 via the CVT 31 and is transmitted to the driving wheel 80 as a driving force for driving the driving wheel 80. Is done.

  In the modification, in the engine running mode, the transmission ECU 300 engages the engine clutch 42 and the first transmission clutch 44. Engine ECU 200 drives engine 10 to output torque. Thereby, the torque output from the engine 10 is transmitted to the secondary shaft 36 via the CVT 31, and is transmitted to the drive wheel 80 as a drive force for driving the drive wheel 80.

  In the modification, in the hybrid travel mode, the transmission ECU 300 engages the engine clutch 42 and the first transmission clutch 44. Engine ECU 200 drives engine 10 to output torque. The motor ECU 400 drives at least one of the first motor generator 20 and the second motor generator 24 via the inverter 70 to output torque. Thereby, the torque output from the engine 10 is transmitted to the secondary shaft 36 via the CVT 31, and combined with the torque output from at least one of the first motor generator 20 and the second motor generator 24, The driving force for driving the driving wheel 80 is transmitted to the driving wheel 80.

<6. Conclusion>
As described above, according to the present embodiment, the travel mode setting unit 102 is configured so that the second motor generator 24 operates in the first travel mode in which the driving wheels 80 are driven by the output of the second motor generator 24. When the temperature exceeds the threshold value, the mode is switched to the second traveling mode in which the driving wheels 80 are driven using at least the output of the first motor generator 20. Thereby, when the second motor generator 24 is locked, the driving force for driving the driving wheels 80 can be output to the first motor generator 20. Therefore, when the second motor generator 24 is locked, the shortage of the target torque due to the decrease in the output of the second motor generator 24 can be compensated without starting the engine 10. Therefore, when the drive motor is locked, it is possible to compensate for a shortage of the target torque due to a decrease in the output of the drive motor without causing the driver to feel uncomfortable.

  In the above, the second motor torque calculation unit 108 performs the second torque command when the switching to the twin motor EV travel mode is performed in response to the temperature of the second motor generator 24 exceeding the threshold value TH1. Although the example in which the value is decreased has been described, the second motor torque calculation unit 108 may increase the second torque command value after decreasing it. For example, when the temperature of the second motor generator 24 has decreased to the extent that the second motor generator 24 can output the target torque after switching to the twin motor EV travel mode, The motor torque calculation unit 108 may calculate the second torque command value so as to be approximately equal to the first torque command value. As a result, the amount of heat generated per motor generator can be reduced, so that the time until one of the first motor generator 20 and the second motor generator 24 reaches the limit temperature is increased. be able to.

  In the above description, an example in which the vehicle drive system 1 according to the present embodiment includes two motor generators has been described. However, the technical scope of the present invention is not limited to such an example. For example, the present invention can be applied to a vehicle including three or more motor generators.

  Further, the processing described using the flowchart in the present specification may not necessarily be executed in the order shown in the flowchart. Some processing steps may be performed in parallel. Further, additional processing steps may be employed, and some processing steps may be omitted.

  The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can make various modifications or application examples within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

1, 2 Drive system 10 Engine 11 Crankshaft 15 Oil pump 20 First motor generator (M / G1)
21 Motor shaft 24 Second motor generator (M / G2)
25 Motor shaft 28 Oil pump 30 Automatic transmission 31 Continuously variable transmission (CVT)
33 Primary pulley 34 Primary shaft 35 Secondary pulley 36 Secondary shaft 37 Power transmission member 42 Engine clutch 44 First transmission clutch 46 Second transmission clutch 50 High voltage battery 55 DC / DC converter 60 Low voltage battery 70 Inverter 80 Drive wheel 91 First temperature sensor 93 Second temperature sensor 95 Accelerator opening sensor 97 Vehicle speed sensor 99 Battery remaining capacity sensor 100 Hybrid control unit (hybrid ECU)
102 travel mode setting unit 104 first motor torque calculating unit 106 first output limiting unit 108 second motor torque calculating unit 110 second output limiting unit 112 engine torque calculating unit 114 clutch state setting unit 200 engine control unit ( Engine ECU)
300 Transmission control unit (transmission ECU)
400 Motor control unit (motor ECU)

Claims (10)

An engine capable of outputting a driving force for driving the driving wheels;
A first motor generator and a second motor generator capable of independently outputting a driving force for driving the driving wheels;
A control device for a hybrid vehicle comprising:
A travel mode setting unit for setting the travel mode of the hybrid vehicle according to the travel state;
The travel mode setting unit is configured to perform at least the first operation when the temperature of the second motor generator exceeds a threshold value during the first travel mode in which the driving wheel is driven by the output of the second motor generator. Switching to a second travel mode for driving the drive wheels using the output of the motor generator of
Control device for hybrid vehicle. An output limiting unit that limits the output of the second motor generator when the temperature of the second motor generator exceeds a limit temperature;
The threshold is set to the limit temperature,
The hybrid vehicle control device according to claim 1. An output limiting unit that limits the output of the second motor generator when the temperature of the second motor generator exceeds a limit temperature;
The threshold is set to a temperature lower than the limit temperature.
The hybrid vehicle control device according to claim 1. A first motor torque calculator that calculates a first torque command value that is a torque command value of the first motor generator;
A second motor torque calculation unit that calculates a second torque command value that is a torque command value of the second motor generator;
With
The second motor torque calculation unit decreases the second torque command value when switching to the second travel mode is performed,
The first motor torque calculation unit subtracts the second torque command value from a target torque that is a target value of torque transmitted to the drive wheels when switching to the second traveling mode is performed. And calculating the value obtained as the first torque command value,
The control apparatus of the hybrid vehicle as described in any one of Claims 1-3.   The second motor torque calculation unit decreases the second torque command value so that the second torque command value approaches a predetermined value when switching to the second travel mode is performed. The control apparatus of the hybrid vehicle of Claim 4.   The travel mode setting unit switches to the first travel mode when the temperature of the second motor generator falls below a predetermined first temperature during the second travel mode. The hybrid vehicle control device according to claim 5. When the threshold is the first threshold,
The travel mode setting unit switches to the first travel mode when the temperature of the first motor generator exceeds a second threshold during the second travel mode.
The control apparatus of the hybrid vehicle as described in any one of Claims 1-6. When the threshold value is the first threshold value, and the temperature of the first motor generator exceeds the second threshold value during the second traveling mode,
The first motor torque calculation unit decreases the first torque command value,
The second motor torque calculation unit calculates, as the second torque command value, a value obtained by subtracting the first torque command value from a target torque that is a target value of torque transmitted to the drive wheels. ,
The hybrid vehicle control device according to claim 4 or 5.   The travel mode setting unit is configured such that the temperature of the first motor generator is lower than a predetermined second temperature when the temperature of the second motor generator exceeds the threshold during the first travel mode. And when the remaining capacity of the battery which supplies electric power to the first motor generator is greater than or equal to a predetermined remaining capacity, the mode is switched to the second traveling mode. Hybrid vehicle control device. An engine capable of outputting a driving force for driving the driving wheels;
A first motor generator and a second motor generator capable of independently outputting a driving force for driving the driving wheels;
A control device for a hybrid vehicle according to claim 1;
A hybrid vehicle comprising:

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