JP2009166516A - Hybrid vehicle and its control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To more properly execute operation and an operation stop of an internal combustion engine in each driving mode, in a hybrid vehicle allowing selection of the plurality of driving modes. <P>SOLUTION: In this hybrid vehicle 20, an engine start-up decision threshold value Tr1 and an engine stop decision threshold value Tr0 are set in each of a normal mode, a power mode and an ECO mode such that they correspond to the driving mode selected as an executing driving mode (steps S40, S50, S60). During traveling of the hybrid vehicle 20, permission/non-permission of the operation stop of the engine 22 is decided by comparing requirement torque Tr*, and the engine stop decision threshold value Tr0 or the engine start-up decision threshold value Tr1, and the engine 22 and motors MG1, MG2 are controlled such that torque based on the requirement torque Tr* can be obtained with the operation or the operation stop of the engine 22 according to a result of the decision under the executing driving mode. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a hybrid vehicle and a control method thereof.

Conventionally, as a hybrid vehicle including an engine and a motor, when the target torque calculated based on the accelerator opening is smaller than a predetermined threshold, the vehicle travels without allowing the engine to start, and the target torque is When it becomes larger than a threshold value, what permits an engine start according to the remaining capacity, temperature, etc. of a battery is known (for example, refer patent document 1). In this hybrid vehicle, the threshold value with respect to the target torque is set to be higher for the driving mode in which fuel efficiency is given priority, so that when the driving mode in which fuel efficiency is given priority is selected, compared to when the driving mode has priority driving force. The engine is difficult to start. Further, conventionally, an planetary gear mechanism connected to the engine, the first motor and the axle, a second motor connected to the axle, and a battery capable of exchanging electric power with the first and second motors. A hybrid vehicle provided is known (for example, see Patent Document 2). This hybrid vehicle further includes an eco switch for switching between a fuel efficiency priority mode that prioritizes fuel efficiency and a normal travel mode for normal driving, and is determined when the eco switch is turned on and the fuel efficiency priority mode is selected. When driving at high speed, the engine operation is stopped when the required torque is less than the fuel efficiency lower limit torque, and when the required torque is greater than the fuel efficiency lower limit torque, the fuel efficiency good range where the fuel efficiency is good among the operating points on the optimum fuel efficiency operation line. The engine is operated at the operating point.
JP 2007-554436 A JP 2006-321466 A

  As described above, by preparing a plurality of driving modes (driving modes) of the hybrid vehicle, it is possible to meet various needs of the driver. However, in order to meet the conflicting needs such as improvement in fuel consumption and high output in such a hybrid vehicle, it is necessary to more appropriately execute (start) and stop the operation of the internal combustion engine.

  In view of the above, the main object of the present invention is to enable more appropriate execution and stoppage of an internal combustion engine for each operation mode in a hybrid vehicle capable of selecting a plurality of operation modes.

  The hybrid vehicle and the control method thereof according to the present invention employ the following means in order to achieve the above-described object.

The hybrid vehicle according to the present invention is
A hybrid vehicle including an internal combustion engine capable of outputting power for traveling, an electric motor capable of outputting power for traveling, and power storage means capable of exchanging electric power with the motor,
Compared to the first driving mode for normal driving, the second driving mode that prioritizes the output response of driving power compared to the first driving mode, and the first and second driving modes. An operation mode selection means for selecting any one of the third operation modes giving priority to fuel consumption as the execution operation mode;
Requested torque setting means for setting a requested torque required for traveling;
Threshold setting means for setting a torque threshold for determining whether or not to stop operation of the internal combustion engine by comparison with the set required torque so as to correspond to the operation mode selected as the execution operation mode;
A determining means for comparing the set required torque with the set torque threshold to determine whether or not to stop the operation of the internal combustion engine;
The internal combustion engine and the electric motor so that a torque based on the set required torque can be obtained with the operation or the operation stop of the internal combustion engine according to the determination result by the determination means under the execution operation mode. Control means for controlling
Is provided.

  In this hybrid vehicle, as the operation mode for execution, a first operation mode for normal travel, a second operation mode that prioritizes output responsiveness of power for travel compared to the first operation mode, It is possible to select any one of the third operation modes giving priority to the fuel consumption as compared with the first and second operation modes. Further, in this hybrid vehicle, the torque threshold for determining whether or not to stop the operation of the internal combustion engine by comparing with the required torque required for traveling corresponds to the operation mode selected as the execution operation mode, that is, It is set for each of the first, second and third operation modes. Then, whether or not the internal combustion engine is stopped is determined by comparing the required torque with the torque threshold, and the internal combustion engine is operated or stopped according to the determination result under the operation mode for execution. The internal combustion engine and the electric motor are controlled so that a torque based on the required torque is obtained. As a result, any one of the first driving mode for normal driving, the second driving mode that prioritizes output responsiveness of power for driving, and the third driving mode that prioritizes fuel consumption is set as the execution driving mode. Even if selected, it is possible to more appropriately execute the operation and the operation stop of the internal combustion engine so as to match the respective priorities for each of the first to third operation modes.

  The determination means prohibits the operation stop of the internal combustion engine when the set required torque is equal to or greater than a torque threshold for the operation stop of the internal combustion engine when the operation of the internal combustion engine is stopped. The threshold setting means may use the torque threshold for stopping operation of the internal combustion engine as the execution operation mode as the first operation mode when the second operation mode is selected as the execution operation mode. Alternatively, when the third operation mode is selected, the torque threshold value for stopping the operation of the internal combustion engine is set when the third operation mode is selected as the execution operation mode. It may be set larger than when the first or second operation mode is selected as the execution operation mode. As a result, when the second operation mode that prioritizes the output responsiveness of power for traveling is selected, the first operation mode for normal traveling and the third operation mode that prioritizes fuel consumption are selected. Compared to the case, it is more difficult to stop the operation of the internal combustion engine, and when the internal combustion engine is stopped, the internal combustion engine tends to be started or the operation of the internal combustion engine is continued. It is possible to quickly obtain the power of the vehicle with good responsiveness, and it is possible to satisfactorily satisfy the high output demand from the driver. Further, when the third driving mode giving priority to fuel consumption is selected, the first driving mode for normal driving or the second driving mode giving priority to output response of driving power is selected. Compared to the above, it is easier to permit the operation of the internal combustion engine to be stopped, and it is possible to improve the fuel consumption by stopping the operation of the internal combustion engine when it is unnecessary or continuing the operation stop of the internal combustion engine. It becomes. In addition, when the first driving mode for normal driving is selected, the internal combustion engine is operated and stopped so that the fuel efficiency and the driving performance are well balanced in the driving of a general hybrid vehicle. It becomes possible to do.

  Further, the determination means may permit the operation stop of the internal combustion engine when the set required torque is less than a torque threshold for operation of the internal combustion engine during operation of the internal combustion engine. Preferably, the threshold setting means sets the torque threshold for operation of the internal combustion engine to be smaller than the torque threshold for operation stop of the internal combustion engine, and the second operation mode as the execution operation mode. Is selected, the torque threshold for operation of the internal combustion engine is set to be smaller than that in the case where the first or third operation mode is selected as the execution operation mode. Good. As described above, by setting the torque threshold value for operating the internal combustion engine to be smaller than the torque threshold value for stopping the internal combustion engine, it is possible to suppress frequent start and stop of the internal combustion engine. Can do. When the second operation mode is selected, if the torque threshold for operation of the internal combustion engine is set smaller than that when the first or third operation mode is selected, the second When the internal combustion engine is operated with the operation mode selected, the operation of the internal combustion engine is hardly stopped, that is, the operation of the internal combustion engine can be easily continued.

  The torque threshold for stopping the operation of the internal combustion engine is a value obtained by subtracting a predetermined margin from the rated maximum torque of the electric motor, and the margin is between the first, second and third operation modes. May be different. As a result, it is possible to permit the operation stop of the internal combustion engine within a range in which a good running torque can be obtained from the electric motor.

  Further, when the vehicle speed is equal to or higher than a predetermined intermittent prohibition vehicle speed, the control means can obtain a torque based on the set required torque with the operation of the internal combustion engine regardless of the determination result by the determination means. Alternatively, the internal combustion engine and the electric motor may be controlled. Thereby, when the operation of the internal combustion engine is to be continued due to various factors, it is possible to suppress the operation of the internal combustion engine from being stopped based on the required torque and the torque threshold value.

  The required torque setting means includes a required torque setting restriction corresponding to the first operation mode, a required torque setting restriction corresponding to the second operation mode, and a required torque setting restriction corresponding to the third operation mode. Among them, the required torque corresponding to the torque request operation by the driver may be set using the required torque setting restriction corresponding to the execution operation mode, and the required torque corresponding to the second operation mode. The setting constraint may have a tendency to set the required torque for the same torque request operation larger than the required torque setting constraint corresponding to the first and third operation modes. This makes it possible to satisfactorily satisfy the high output request from the driver when the second operation mode that prioritizes the output responsiveness of the driving power is selected.

  Further, the hybrid vehicle is connected to a predetermined axle and an engine shaft of the internal combustion engine, and outputs at least part of the power of the internal combustion engine to the axle side with input and output of electric power and power, and the Electric power power input / output means capable of exchanging electric power with the power storage means may be further provided, and the electric motor may be capable of outputting power to the axle or another axle different from the axle. In this case, the power drive input / output means can input / output power and can exchange power with the power storage means, the axle, the engine shaft of the internal combustion engine, and the power generation motor. A three-axis power input / output means for inputting / outputting power to / from the remaining shafts based on power input / output to / from any two of these three axes. There may be.

The hybrid vehicle control method according to the present invention includes:
An internal combustion engine capable of outputting driving power, an electric motor capable of outputting driving power, power storage means capable of exchanging electric power with the motor, a first operation mode for normal driving, and the first Execute either the second operation mode that prioritizes the output responsiveness of the driving power compared to the operation mode or the third operation mode that prioritizes fuel consumption compared to the first and second operation modes. A control method for a hybrid vehicle comprising driving mode selection means for selecting as a driving mode for operation,
(A) setting a torque threshold value for determining whether or not to stop the operation of the internal combustion engine by comparing with a required torque required for traveling so as to correspond to the operation mode selected as the execution operation mode; ,
(B) comparing the required torque with the torque threshold set in step (a) to determine whether or not to stop the operation of the internal combustion engine;
(C) Under the execution operation mode, the internal combustion engine and the internal combustion engine and the Controlling the electric motor;
Is included.

  According to this method, any one of the first driving mode for normal driving, the second driving mode that gives priority to output responsiveness of driving power, and the third driving mode that gives priority to fuel consumption is used. Even if the operation mode is selected, it is possible to more appropriately execute the operation and the operation stop of the internal combustion engine so as to match the respective priorities for each of the first to third operation modes.

  Next, the best mode for carrying out the present invention will be described using examples.

  FIG. 1 is a schematic configuration diagram of a hybrid vehicle 20 according to an embodiment of the present invention. A hybrid vehicle 20 shown in the figure is connected to an engine 22, a three-shaft power distribution and integration mechanism 30 connected to a crankshaft 26 that is an output shaft of the engine 22 via a damper 28, and the power distribution and integration mechanism 30. The motor MG1 capable of generating electricity, the reduction gear 35 attached to the ring gear shaft 32a as an axle connected to the power distribution and integration mechanism 30, and the motor MG2 connected to the ring gear shaft 32a via the reduction gear 35 , Inverters 41 and 42 that can convert DC current into AC current and supply them to motors MG1 and MG2, a step-up / down converter 55 that can convert electric power from battery 50 and supply it to inverters 41 and 42, and a hybrid vehicle 20 is an electronic control unit for hybrid (hereinafter referred to as “hybrid ECU”). U) in which and a 70, and the like.

  The engine 22 is an internal combustion engine that outputs power when supplied with hydrocarbon-based fuel such as gasoline or light oil. The fuel injection amount or ignition timing by an engine electronic control unit (hereinafter referred to as “engine ECU”) 24, Control of intake air volume etc. The engine ECU 24 receives signals from various sensors that are provided for the engine 22 and detect the operating state of the engine 22. The engine ECU 24 communicates with the hybrid ECU 70 to control the operation of the engine 22 based on a control signal from the hybrid ECU 70, a signal from the sensor, and the like, and to transmit data on the operation state of the engine 22 as necessary. It outputs to ECU70.

  The power distribution and integration mechanism 30 includes an external gear sun gear 31, an internal gear ring gear 32 arranged concentrically with the sun gear 31, a plurality of pinion gears 33 that mesh with the sun gear 31 and mesh with the ring gear 32, A planetary gear mechanism is provided that includes a carrier 34 that holds a plurality of pinion gears 33 so as to rotate and revolve, and that performs differential action using the sun gear 31, the ring gear 32, and the carrier 34 as rotating elements. The crankshaft 26 of the engine 22 is connected to the carrier 34 as the engine side rotation element, the motor MG1 is connected to the sun gear 31, and the reduction gear 35 is connected to the ring gear 32 as the axle side rotation element via the ring gear shaft 32a. The power distribution and integration mechanism 30 distributes the power from the engine 22 input from the carrier 34 to the sun gear 31 side and the ring gear 32 side according to the gear ratio when the motor MG1 functions as a generator. When the motor functions as an electric motor, the power from the engine 22 input from the carrier 34 and the power from the motor MG1 input from the sun gear 31 are integrated and output to the ring gear 32 side. The power output to the ring gear 32 is finally output from the ring gear shaft 32a to the wheels 39a and 39b which are drive wheels via the gear mechanism 37 and the differential gear 38.

  Each of the motors MG1 and MG2 is configured as a known synchronous generator motor that operates as a generator and can operate as a motor, and exchanges power with the battery 50 that is a secondary battery via inverters 41 and 42. . The power line 54 connecting the inverters 41 and 42 and the battery 50 is configured as a positive bus and a negative bus shared by the inverters 41 and 42, and the power generated by one of the motors MG1 and MG2 is supplied to the other. It can be consumed with the motor. Therefore, the battery 50 is charged / discharged by the electric power generated from one of the motors MG1 and MG2 or the insufficient electric power. If the electric power balance is balanced by the motors MG1 and MG2, the battery 50 is charged. It will not be discharged. The motors MG1 and MG2 are both driven and controlled by a motor electronic control unit (hereinafter referred to as “motor ECU”) 40. The motor ECU 40 receives signals necessary for driving and controlling the motors MG1 and MG2, such as signals from rotational position detection sensors 43 and 44 that detect the rotational positions of the rotors of the motors MG1 and MG2, and current sensors (not shown). The detected phase current applied to the motors MG1 and MG2 is input, and the motor ECU 40 outputs a switching control signal and the like to the inverters 41 and 42. Further, the motor ECU 40 executes a rotation speed calculation routine (not shown) based on signals input from the rotation position detection sensors 43 and 44, and calculates the rotation speeds Nm1 and Nm2 of the rotors of the motors MG1 and MG2. Further, the motor ECU 40 communicates with the hybrid ECU 70, and controls the drive of the motors MG1 and MG2 based on a control signal from the hybrid ECU 70 and transmits data related to the operation state of the motors MG1 and MG2 to the hybrid ECU 70 as necessary. Output.

  The battery 50 is managed by a battery electronic control unit (hereinafter referred to as “battery ECU”) 52. The battery ECU 52 includes signals necessary for managing the battery 50, for example, the battery voltage VB from the first voltage sensor 91 installed between the terminals of the battery 50, and the power line 54 connected to the output terminal of the battery 50. The charging / discharging current from a current sensor (not shown) attached to the battery, the battery temperature Tb from the temperature sensor 51 attached to the battery 50, and the like are input. The battery ECU 52 outputs data related to the state of the battery 50 to the hybrid ECU 70 and the engine ECU 24 by communication as necessary. Further, in order to manage the battery 50, the battery ECU 52 calculates the remaining capacity SOC based on the integrated value of the charging / discharging current detected by the current sensor, or requests charging / discharging of the battery 50 based on the remaining capacity SOC. The power Pb * is calculated, or the input limit Win as the charge allowable power that is the power allowed for charging the battery 50 based on the remaining capacity SOC and the battery temperature Tb, and the power allowed for discharging the battery 50. The output limit Wout as discharge allowable power is calculated. The input / output limits Win and Wout of the battery 50 set basic values of the input / output limits Win and Wout based on the battery temperature Tb, and output correction correction coefficients based on the remaining capacity (SOC) of the battery 50. It can be set by setting a correction coefficient for input restriction and multiplying the basic value of the set input / output restrictions Win and Wout by the correction coefficient.

  The step-up / down converter 55 includes, for example, first and second transistors (not shown), first and second diodes connected in parallel to the first and second transistors in the reverse direction, and a reactor. The battery 50 is connected via the system main relay 56. Further, a capacitor (not shown) is arranged between the reactor of the buck-boost converter 55 and the negative electrode bus. Between the terminals of the capacitor, a voltage VL for detecting the voltage VL before or after boosting of the buck-boost converter 55 is detected. A two-voltage sensor 92 is installed. Further, a smoothing capacitor 57 is disposed between the step-up / down converter 55 and the inverter 41, and a voltage VH before or after step-up / step-down of the step-up / down converter 55 is detected between terminals of the capacitor 57. A third voltage sensor 93 is installed. By switching and controlling the first and second transistors of such a step-up / down converter 55, the DC power from the battery 50 is boosted and supplied to the inverters 41 and 42, or acts on the positive and negative buses. The battery 50 can be charged by stepping down the direct current voltage. That is, the first and second transistors of the step-up / down converter 55 basically include the battery 50 and the two motors based on the voltage values VL and VH detected by the second voltage sensor 92 and the third voltage sensor 93. Switching is controlled so that the boosted voltage VH becomes the voltage command VH * or the stepped-down voltage VL becomes the voltage command VL * in order to smoothly exchange power between MG1 and MG2.

  The hybrid ECU 70 is configured as a microprocessor centered on the CPU 72, and includes a ROM 74 that stores a processing program, a RAM 76 that temporarily stores data, an input / output port and a communication port (not shown), in addition to the CPU 72. . The hybrid ECU 70 detects the ignition signal from the ignition switch (start switch) 80, the shift position SP from the shift position sensor 82 that detects the shift position SP that is the operation position of the shift lever 81, and the depression amount of the accelerator pedal 83. The accelerator opening Acc from the accelerator pedal position sensor 84, the brake pedal stroke BS from the brake pedal stroke sensor 86 for detecting the depression amount of the brake pedal 85, the vehicle speed V from the vehicle speed sensor 87, and the voltage VL from the second voltage sensor 92. The voltage VH from the third voltage sensor 93 is input through the input port. Further, in the vicinity of the driver's seat of the hybrid vehicle 20 of the embodiment, a power switch (driving mode) for selecting a power mode (second driving mode) that gives priority to power performance, that is, responsiveness of torque output to the accelerator operation, as the driving mode (Mode selection means) 88 is provided, and this power switch 88 is also connected to the hybrid ECU 70. Further, in the vicinity of the driver's seat of the hybrid vehicle 20 of the embodiment, an ECO switch (operation mode selection means) for selecting an ECO mode (third operation mode) giving priority to the fuel efficiency and energy efficiency of the engine 22 as the operation mode. 89 is provided, and this ECO switch 89 is also connected to the hybrid ECU 70. As described above, the hybrid ECU 70 is connected to the engine ECU 24, the motor ECU 40, the battery ECU 52, etc. via the communication port, and exchanges various control signals and data with the engine ECU 24, the motor ECU 40, the battery ECU 52, etc. ing. Further, the hybrid ECU 70 outputs a drive signal to the system main relay 56, a switching control signal to the step-up / down converter 55, and the like via an output port.

  In the hybrid vehicle 20 of the embodiment configured as described above, the required torque to be output to the ring gear shaft 32a as the axle based on the accelerator opening Acc and the vehicle speed V corresponding to the depression amount of the accelerator pedal 83 by the driver. And the engine 22, the motor MG1, and the motor MG2 are controlled so that torque based on the required torque is output to the ring gear shaft 32a. As the operation control mode of the engine 22, the motor MG1, and the motor MG2, the engine 22 is operated and controlled so that power corresponding to the required torque is output from the engine 22, and all of the power output from the engine 22 is a power distribution integration mechanism. 30, the torque conversion operation mode in which the motors MG 1 and MG 2 are driven and controlled so that the torque is converted by the motor MG 1 and the motor MG 2 and output to the ring gear shaft 32 a, and the sum of the required torque and the power required for charging and discharging the battery 50 The engine 22 is operated and controlled so that power corresponding to the power is output from the engine 22, and all or part of the power output from the engine 22 with charging / discharging of the battery 50 is performed by the power distribution and integration mechanism 30 and the motor MG1. Torque according to the required torque with torque conversion by the motor MG2. Charge / discharge operation mode in which the motors MG1 and MG2 are driven and controlled so that the power is output to the ring gear shaft 32a, and operation control is performed so that the engine 22 is stopped and power corresponding to the required torque is output from the motor MG2 to the ring gear shaft 32a. There are motor operation modes.

  In the hybrid vehicle 20 according to the embodiment, when the power switch 88 is turned off, the normal mode (first driving mode) is selected as the driving mode unless the ECO switch 89 is turned on. In this state, the hybrid ECU 70 sets the predetermined power mode flag Fpwr to a value of 0 and controls the hybrid vehicle 20 according to various control procedures for selecting the normal mode. When the power switch 88 is turned on and the power mode is selected as the operation mode of the hybrid vehicle 20, the hybrid ECU 70 sets the power mode flag Fpwr to a value of 1 and a predetermined power mode selection time. The hybrid vehicle 20 is controlled according to the various control procedures. In the embodiment, when the power mode is selected by the driver, the torque output to the ring gear shaft 32a serving as the axle is increased compared to the case of selecting the normal mode so that the response of the torque output to the accelerator operation by the driver is improved. In addition, the engine 22 and the motors MG1 and MG2 are controlled.

  Further, in the hybrid vehicle 20, when the ECO switch 89 is turned off, the normal mode is selected as the operation mode unless the power switch 88 is turned on. In this state, the hybrid ECU 70 performs a predetermined operation. The hybrid vehicle 20 is controlled in accordance with various control procedures for selecting the normal mode while the ECO flag Feco is set to the value 0. When the ECO switch 89 is turned on and the ECO mode is selected as the operation mode of the hybrid vehicle 20, the hybrid ECU 70 sets the ECO flag Feco to a value of 1 and is used for selecting a predetermined ECO mode. The hybrid vehicle 20 is controlled according to various control procedures. As an example of the control for selecting the ECO mode, there is a prohibition of the step-up / step-down operation by the step-up / step-down converter 55 performed under the normal mode or the power mode. As described above, when the ECO mode is selected, the step-up / step-down operation by the step-up / down converter 55 performed under the normal mode or the like is prohibited, so that the torque output by the motors MG1 and MG2 can be output compared with the case of selecting the normal mode or the like. Although it is limited, by prohibiting the step-up / step-down operation, the switching loss of the first and second transistors of the step-up / down converter 55 is not executed, so that the loss due to switching can be reduced. Therefore, the energy efficiency of the hybrid vehicle 20 can be improved.

  As described above, in the hybrid vehicle 20 that includes the engine 22 and the motor MG2 each capable of outputting power for traveling, and is capable of selecting a plurality of operation modes of the normal mode, the power mode, and the ECO mode, the traveling At this time, it is necessary to more appropriately execute (start) and stop the operation of the engine 22 so that the priority in the operation mode actually used (hereinafter referred to as “execution operation mode”) is satisfied. For this reason, in the hybrid vehicle 20 of the embodiment, a threshold value for determining whether or not the engine is stopped by comparing with the required torque, that is, an engine start determination threshold value used for starting determination of the engine 22 when the engine 22 is stopped. Tr1 (torque threshold value for stopping the operation of the engine 22) and an engine stop determination threshold value Tr0 (torque threshold value for driving the engine 22) used for determining whether the engine 22 is stopped when the engine 22 is operating. 2 is repeatedly executed every predetermined time (for example, several msec) by the hybrid ECU 70 so as to be set so as to correspond to the normal mode, power mode or ECO mode selected as.

  At the start of the determination threshold value setting routine shown in FIG. 2, the CPU 72 of the hybrid ECU 70 executes an input process of data necessary for control such as the values of the power mode flag Fpwr and the ECO flag Feco (step S10). Next, it is determined whether or not the input power mode flag Fpwr is a value 0 (step S20). If the power mode flag Fpwr is a value 0, it is further determined whether or not the ECO flag Feco is a value 0. (Step S30). If both the power mode flag Fpwr and the ECO flag Feco are 0, the normal mode is selected as the operation mode for execution. In this case, the engine start determination threshold value Tr1 is set for the normal mode. The engine stop determination threshold value Tr0 is set and held at the normal mode value Tr0nor (step S40). If it is determined in step S20 that the power mode flag Fpwr is a value 1, the power mode is selected as the execution operation mode. In this case, the engine start determination threshold Tr1 Is set and held at the power mode value Tr1pwr, and the engine stop determination threshold Tr0 is set and held at the power mode value Tr0pwr (step S50). Further, when it is determined in step S30 that the ECO flag Feco is a value 1 when the power mode flag is a value 0, the ECO mode is selected as the execution operation mode. In this case, the engine start determination threshold value Tr1 is set / held at the ECO mode value Tr1eco, and the engine stop determination threshold value Tr0 is set / held at the ECO mode value Tr0eco (step S60). Thus, when the engine start determination threshold value Tr1 and the engine stop determination threshold value Tr0 are set in any one of steps S40 to S60, the CPU 72 repeatedly executes the processes in and after step S10.

  Here, the values Tr1nor, Tr1pwr, and Tr1eco set as the engine start determination threshold value Tr1 are obtained by subtracting a predetermined margin from the rated maximum torque of the motor MG2, respectively. The value is different between the ECO modes. The value Tr1nor set as the engine start determination threshold value Tr1 for the normal mode and the value Tr0nor set as the engine stop determination threshold value Tr0 for the normal mode are suppressed as much as possible from vibration and noise associated with starting / stopping the engine 22. In addition, in a general driving state of the hybrid vehicle 20, it is determined through experiments and analyzes so that the fuel efficiency and the driving performance are balanced. In the embodiment, the value Tr1pwr set as the engine start determination threshold value Tr1 for the power mode is set as the value Tr1nor set as the engine start determination threshold value Tr1 for the normal mode or the engine start determination threshold value Tr1 for the ECO mode. It is set to a value smaller than the value Tr1eco. Further, the value Tr1eco set as the engine start determination threshold value Tr1 for the ECO mode is the value Tr1nor set as the engine start determination threshold value Tr1 for the normal mode or the value Tr1pwr set as the engine start determination threshold value Tr1 for the power mode. Is set to a larger value. Therefore, the relationship of the following expression (1) is established among the values Tr1nor, Tr1pwr, and Tr1eco. Further, the engine stop determination threshold value Tr0, which is a torque threshold value for driving the engine 22, is set to a value smaller than the engine start determination threshold value Tr1, which is a torque threshold value for stopping the operation of the engine 22, and the engine stop for power mode is stopped. The value Tr0pwr set as the determination threshold Tr0 is smaller than the value Tr0nor set as the engine stop determination threshold Tr0 for the normal mode and the value Tr0eco set as the engine stop determination threshold Tr0 for the ECO mode. Therefore, the relationship of the following equation (2) is established between the values Tr1nor, Tr1pwr and Tr1eco and the values Tr0nor, Tr0pwr and Tr0eco.

Tr1eco>Tr1nor> Tr1pwr (1)
Tr1nor> Tr0nor, Tr1pwr> Tr0pwr, Tr1eco> Tr0eco, Tr0nor> Tr0pwr, Tr0eco> Tr0pwr (2)

  Next, the operation of the hybrid vehicle 20 of the embodiment will be described. FIG. 3 is a flowchart illustrating an example of a drive control routine that is repeatedly executed by the hybrid ECU 70 according to the embodiment every predetermined time (for example, several milliseconds).

  At the start of the drive control routine shown in FIG. 3, the CPU 72 of the hybrid ECU 70 determines the accelerator opening Acc from the accelerator pedal position sensor 84, the vehicle speed V from the vehicle speed sensor 87, the rotational speeds Nm 1 and Nm 2 of the motors MG 1 and MG 2, Input processing of data necessary for control such as required discharge power Pb *, input / output limits Win and Wout of the battery 50, engine start determination threshold Tr1, engine stop determination threshold Tr0, power mode flag Fpwr value, and ECO flag Feco value Execute (Step S100). The rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 are input from the motor ECU 40 through communication, and the charge / discharge request power Pb * and the input / output limits Win and Wout are input from the battery ECU 52 through communication. Further, the engine start determination threshold value Tr1 and the engine stop determination threshold value Tr0 are set through the above-described determination threshold value routine of FIG. 2 and held in a predetermined storage area. Further, as described above, the power mode flag Fpwr and the ECO flag Feco are set by the hybrid ECU 70 according to the operation state of the power switch 88 and the ECO switch 89 by the driver, and are held in a predetermined storage area.

  After the data input process of step S100, the normal operation mode, the power mode, and the ECO mode are executed as the operation mode for execution based on the input power mode flag Fpwr and ECO mode flag Feco in the same manner as in steps S20 and S30 of FIG. Which one is selected is determined (step S110). When both the power mode flag Fpwr and the ECO mode flag Feco are 0 and the normal mode is selected as the operation mode for execution, the accelerator opening Acc and the required torque setting constraint input in step S100 The accelerator opening for execution Acc *, which is the accelerator opening for control, is set using the normal-mode accelerator opening setting map (step S120). If the power mode flag Fpwr is 1 and the power mode is selected as the operation mode for execution, the accelerator opening amount Acc input in step S100 and the accelerator opening in the power mode as the required torque setting constraint are opened. An execution accelerator opening Acc *, which is an accelerator opening for control, is set using the degree setting map (step S130). Further, when the ECO flag Feco is 1 and the ECO mode is selected as the execution operation mode, the accelerator opening Acc input in step S100 and the accelerator opening in the ECO mode as the required torque setting constraint An execution accelerator opening Acc *, which is an accelerator opening for control, is set using the setting map (step S140). FIG. 4 illustrates an accelerator opening setting map for normal mode, an accelerator opening setting map for power mode, and an accelerator opening setting map for ECO mode.

  As shown in FIG. 4, the normal mode accelerator opening setting map of the embodiment is preliminarily set so that the execution accelerator opening Acc * is linear with respect to the accelerator opening Acc in the range of 0 to 100%. It is created and stored in the ROM 74. The normal mode accelerator opening setting map illustrated in FIG. 4 is created so that the accelerator opening Acc is set as the execution accelerator opening Acc * as it is. Further, as shown in FIG. 4, the map for setting the accelerator opening in the power mode of the embodiment corresponds to the accelerator opening Acc in an arbitrary low accelerator opening region so as to suppress the feeling of jumping out of the vehicle at the low vehicle speed. In the normal mode, the same value as that set by the accelerator opening setting map is set as the execution accelerator opening Acc *, and the accelerator opening Acc up to 100% other than the low accelerator opening range is set. Is created so as to set a value larger than that set by the accelerator opening setting map in normal mode as the accelerator opening Acc * for execution in order to improve the response of the torque output to the accelerator operation, and is stored in the ROM 74. Has been. Further, as shown in FIG. 4, the map for setting the accelerator opening in the ECO mode is smaller than that set by the map for setting the accelerator opening in the normal mode in order to reduce the response of the torque output to the accelerator operation. Is set as the accelerator opening Acc * for execution, and is stored in the ROM 74.

  If the execution accelerator opening Acc * is set in step S120, S130 or S140, it is output to the ring gear shaft 32a as the axle based on the execution accelerator opening Acc * and the vehicle speed V input in step S100. After setting the required torque Tr *, the required power P * required for the entire vehicle is set (step S150). In the embodiment, the relationship among the accelerator opening Acc * for execution, the vehicle speed V, and the required torque Tr * is determined in advance and stored in the ROM 74 as a required torque setting map (required torque setting constraint). As for, the thing corresponding to the given accelerator opening Acc * for execution and the vehicle speed V is derived and set from the map. FIG. 5 shows an example of the required torque setting map. As a result of such processing being performed, if the accelerator opening Acc * for execution is set larger than when the normal mode or the like is selected when the power mode is selected by the driver, the required torque is accordingly increased. Tr * is set larger than when normal mode or the like is selected. Further, if the accelerator opening Acc * for execution is set smaller than that when the normal mode or the like is selected when the ECO mode is selected by the driver, the required torque Tr * is selected accordingly according to the normal mode or the like. It will be set smaller than sometimes. In the embodiment, the required power P * is calculated as the sum of the set required torque Tr * multiplied by the rotation speed Nr of the ring gear shaft 32a, the charge / discharge required power Pb *, and the loss Loss. The rotational speed Nr of the ring gear shaft 32a can be obtained by dividing the rotational speed Nm2 of the motor MG2 by the gear ratio Gr of the reduction gear 35 as shown in the figure or by multiplying the vehicle speed V by the conversion factor k.

  Next, it is determined whether or not the engine 22 is operating (step S160). If it is determined in step S160 that the engine 22 is operating, it is determined whether or not the vehicle speed V input in step S100 is less than a predetermined intermittent prohibition vehicle speed Vref (step S170). Is less than the intermittent prohibition vehicle speed Vref, it is further determined whether or not the required torque Tr * set in step S150 is equal to or greater than the engine stop determination threshold value Tr0 input in step S100 (step S180). Here, the intermittent prohibition vehicle speed Vref is set, for example, as a lower limit value of a vehicle speed range where the operation of the engine 22 is necessary and the intermittent operation should be prohibited, and the state of the battery 50, the state of the engine 22, and the traveling state of the hybrid vehicle 20 It may be set to change according to the above. If it is determined in step S170 that the vehicle speed V is greater than or equal to the intermittent prohibition vehicle speed Vref, or if it is determined in step S180 that the required torque Tr * is greater than or equal to the engine stop determination threshold value Tr0, the vehicle speed V The required torque Tr * to be output to the ring gear shaft 32a can be provided only by the torque from the motor MG2 in relation to the output power of the motor MG2 (rotation speed Nm2 × torque Tm2) and the rated maximum torque of the motor MG2. Considering that there is a possibility that the engine 22 will be lost, the temporary target rotational speed Netmp and the temporary target torque, which are temporary target operating points of the engine 22, based on the required power P * in order to prohibit the operation stop of the engine 22 and continue the operation. Set Tempmp (step S190). In the embodiment, the temporary target rotational speed Netmp and the temporary target torque Tentmp of the engine 22 are set based on the operation line for efficiently operating the engine 22 and the required power P *. FIG. 6 illustrates an operation line of the engine 22 and a correlation curve between the rotational speed Ne and the torque Te. As shown in the figure, the temporary target rotational speed Nettmp and the temporary target torque Tempmp can be obtained as an intersection of the operation line and a correlation curve indicating that the required power P * (Netmp × Tempp) is constant. .

  If the temporary target rotational speed Nettmp and the temporary target torque Tentmp of the engine 22 are set, whether or not the power mode flag Fpwr input in step S100 is 1 and the power mode is selected as the operation mode for execution. (Step S200), and if the power mode is not selected as the operation mode for execution, the temporary target rotational speed Netmp is set as the target rotational speed Ne * of the engine 22, and the temporary target torque Tempmp is set as the target torque of the engine 22. Set as Te * (step S210). Further, when the power mode is selected as the execution operation mode, an engine lower limit rotation speed Nemin that is a lower limit value of the rotation speed Ne of the engine 22 is set so that torque can be quickly output from the engine 22. (Step S220). In the embodiment, the relationship between the vehicle speed V and the engine lower limit rotational speed Nemin is determined in advance and stored in the ROM 74 as an engine lower limit rotational speed setting map (not shown). The engine lower limit rotational speed Nemin is given as a given vehicle speed V The one corresponding to is derived and set from the map. If the engine lower limit rotational speed Nemin is set in this way, the larger of the temporary target rotational speed Netmp and the engine lower limit rotational speed Nemin is set as the target rotational speed Ne * of the engine 22, and the required power P set in step S160. The target torque Te * of the engine 22 is set by dividing * by the target rotational speed Ne * (step S230).

  If the target rotational speed Ne * and the target torque Te * of the engine 22 are set in step S210 or S230, the target rotational speed Ne *, the rotational speed Nr (Nm2 / Gr) of the ring gear shaft 32a, and the power distribution and integration mechanism 30 are set. The target rotational speed Nm1 * of the motor MG1 is calculated according to the following equation (3) using the gear ratio ρ (the number of teeth of the sun gear 31 / the number of teeth of the ring gear 32), and the calculated target rotational speed Nm1 * and the current Is used to set a torque command Tm1 * for the motor MG1 according to the following equation (4) (step S240). Here, Expression (3) is a dynamic relational expression for the rotating element of the power distribution and integration mechanism 30. FIG. 7 illustrates a collinear diagram showing a dynamic relationship between the rotational speed and torque in the rotary element of the power distribution and integration mechanism 30. In the figure, the left S-axis indicates the rotational speed of the sun gear 31 that matches the rotational speed Nm1 of the motor MG1, the central C-axis indicates the rotational speed of the carrier 34 that matches the rotational speed Ne of the engine 22, and the right R-axis. The axis indicates the rotational speed Nr of the ring gear 32 obtained by dividing the rotational speed Nm2 of the motor MG2 by the gear ratio Gr of the reduction gear 35. The two thick arrows on the R axis indicate the torque acting on the ring gear shaft 32a by this torque output when the motor MG1 outputs the torque Tm1, and the reduction gear 35 when the motor MG2 outputs the torque Tm2. And the torque acting on the ring gear shaft 32a via. Expression (3) for obtaining the target rotational speed Nm1 * of the motor MG1 can be easily derived by using the rotational speed relationship in this alignment chart. Expression (4) is a relational expression in feedback control for rotating the motor MG1 at the target rotational speed Nm1 *. In Expression (4), “k1” in the second term on the right side is a gain of the proportional term. “K2” in the third term on the right side is the gain of the integral term.

Nm1 * = Ne * ・ (1 + ρ) / ρ-Nm2 / (Gr ・ ρ) (3)
Tm1 * =-ρ / (1 + ρ) ・ Te * + k1 ・ (Nm1 * -Nm1) + k2 ・ ∫ (Nm1 * -Nm1) dt (4)

  If torque command Tm1 * for motor MG1 is set, input / output limits Win and Wout of battery 50, torque command Tm1 * for motor MG1 set in step S240, and current rotational speeds Nm1 and Nm2 of motors MG1 and MG2 Are used to calculate torque limits Tmin and Tmax as upper and lower limits of torque that may be output from the motor MG2 according to the following equations (5) and (6) (step S250). Further, a temporary motor torque Tm2tmp which is a temporary value of torque to be output from the motor MG2 using the required torque Tr *, the torque command Tm1 *, the gear ratio ρ of the power distribution and integration mechanism 30 and the gear ratio Gr of the reduction gear 35. Is calculated according to the following equation (7) (step S260). Then, the torque command Tm2 * for the motor MG2 is set to a value obtained by limiting the temporary motor torque Tm2tmp with the torque limits Tmin and Tmax (step S270). By setting the torque command Tm2 * for the motor MG2 in this manner, the torque output to the ring gear shaft 32a as the axle can be limited within the range of the input / output limits Win and Wout of the battery 50. Equation (7) can be easily derived from the alignment chart of FIG. If the target rotational speed Ne * and target torque Te * of the engine 22 and torque commands Tm1 * and Tm2 * for the motors MG1 and MG2 are thus set, the target rotational speed Ne * and the target torque Te * of the engine 22 are sent to the engine ECU 24. Then, torque commands Tm1 * and Tm2 * of the motors MG1 and MG2 are transmitted to the motor ECU 40 (step S280), and the processing after step S100 is executed again. The engine ECU 24 that has received the target rotational speed Ne * and the target torque Te * executes control for obtaining the target rotational speed Ne * and the target torque Te *. Further, the motor ECU 40 receiving the torque commands Tm1 * and Tm2 * switches the switching elements of the inverters 41 and 42 so that the motor MG1 is driven according to the torque command Tm1 * and the motor MG2 is driven according to the torque command Tm2 *. Take control. Note that when the ECO mode is selected as the execution operation mode, the step-up / step-down operation of the step-up / down converter 55 is prohibited as described above, and therefore the step-up / step-down operation by the step-up / step-down converter 55 is prohibited. As a result, the torque output from the motor MG2 is limited.

Tmin = (Win-Tm1 * ・ Nm1) / Nm2 (5)
Tmax = (Wout-Tm1 * ・ Nm1) / Nm2 (6)
Tm2tmp = (Tr * + Tm1 * / ρ) / Gr (7)

  If it is determined in step S170 that the vehicle speed V is less than the intermittent prohibition vehicle speed Vref and it is determined in step S180 that the required torque Tr * is less than the engine stop determination threshold value Tr0, a predetermined engine stop is performed. After the flag is turned on (step S290), this routine is terminated. That is, if the vehicle speed V is less than the intermittent vehicle speed Vref and is not included in the vehicle speed range where the engine 22 needs to be operated, if the required torque Tr * is less than the engine stop determination threshold value Tr0, only the motor MG2 is used. Sufficient torque can be output to the ring gear shaft 32a as an axle, so that the operation stop of the engine 22 can be permitted. Accordingly, in this case, the engine stop flag is turned on so that the operation of the engine 22 is stopped. When the engine stop flag is turned on in this way, the hybrid ECU 70 executes an engine stop control routine (not shown). In the engine stop control routine, in a state where fuel supply to the engine 22 is stopped, for example, a negative torque for suppressing the rotation of the engine 22 until the rotation speed Ne of the engine 22 reaches a predetermined rotation speed immediately before the stop is motorized. A torque command Tm1 * for MG1 is set, and a positive torque for holding the piston is set as a torque command Tm1 * for the motor MG1 at the timing when the rotation speed Ne reaches the rotation speed just before the stop. Is a process for setting the torque command Tm2 * of the motor MG2 so that the torque based on is output to the ring gear shaft 32a. When the engine stop control routine ends, the engine stop flag is turned off.

  On the other hand, if it is determined in step S160 that the operation of the engine 22 is stopped, it is determined whether or not the vehicle speed V input in step S100 is less than the intermittent prohibition vehicle speed Vref (step S300). If the vehicle speed V is less than the intermittent prohibition vehicle speed Vref, it is further determined whether or not the required torque Tr * set in step S150 is equal to or higher than the engine start determination threshold Tr1 input in step S100 (step S310). If it is determined in step S310 that the required torque Tr * is less than the engine start determination threshold value Tr1, the target rotation of the engine 22 is allowed so as to permit the operation stop of the engine 22 and continue the operation stop state. The number Ne * and the target torque Te * are each set to a value of 0 (step S320), and the torque command Tm1 * for the motor MG1 is set to a value of 0 (step S330), and the processing from step S250 onward is executed. To do.

  On the other hand, if it is determined in step S300 that the vehicle speed V is equal to or higher than the intermittent prohibition vehicle speed Vref, or if it is determined in step S310 that the required torque Tr * is equal to or higher than the engine start determination threshold value Tr1. Then, after turning on a predetermined engine start flag (step S340), this routine is ended. That is, when the vehicle speed V exceeds the intermittent prohibition vehicle speed Vref and the engine 22 needs to be operated and is included in the vehicle speed range where the intermittent operation should be prohibited, the engine 22 is prohibited from being stopped and the engine 22 is started. There is a need. In addition, even when the vehicle speed V is less than the intermittent prohibition vehicle speed Vref, if the required torque Tr * is equal to or greater than the engine start determination threshold Tr1, sufficient torque cannot be output only from the motor MG2 to the ring gear shaft 32a as the axle. Therefore, it is necessary to start the engine 22 while prohibiting the operation stop of the engine 22. Therefore, in this case, the engine start flag is turned on so that the engine 22 is started. When the engine start flag is turned on in this way, the hybrid ECU 70 executes an engine start time drive control routine (not shown). Note that the engine start drive control routine starts the engine 22 while cranking the engine 22 by the motor MG1, and generates torque as a reaction force against the drive torque acting on the ring gear shaft 32a as the engine 22 is cranked. In this process, the motor MG2 is driven and controlled so that a torque based on the required torque Tr * is output to the ring gear shaft 32a while canceling. When the engine starting drive control routine ends, the engine start flag is turned off.

  As described above, in the hybrid vehicle 20 of the embodiment, as the execution operation mode, the normal mode for normal driving, the power mode that gives priority to the response of the torque output to the accelerator operation as compared with the normal mode, and the normal mode In addition, it is possible to select any of the ECO mode that prioritizes fuel efficiency and energy efficiency as compared with the power mode. Furthermore, in the hybrid vehicle 20, an engine start determination threshold value Tr1 and an engine stop determination threshold value Tr0, which are torque threshold values for determining whether or not to stop the operation of the engine 22 by comparing with the required torque Tr * required for traveling, are executed. It is set so as to correspond to the operation mode selected as the operation mode for operation, that is, for each of the normal mode, power mode and ECO mode (FIG. 2). While the hybrid vehicle 20 is traveling, whether the engine 22 is stopped or not is determined by comparing the required torque Tr * with the engine stop determination threshold value Tr0 or the engine start determination threshold value Tr1 (steps S180 and S310). ) Under the execution operation mode, a torque based on the required torque Tr * can be obtained with the operation (step S340) or the operation stop (step S290) of the engine 22 according to the determination result in step S180 or S310. In addition, the engine 22 and the motors MG1 and MG2 are controlled. As a result, in the hybrid vehicle 20 of the embodiment, any of the normal mode for normal driving, the power mode that prioritizes the responsiveness of torque output with respect to the accelerator operation, and the ECO mode that prioritizes fuel consumption or the like is the execution operation mode. Even if selected, it is possible to more appropriately execute (start) and stop operation of the engine 22 so as to match the respective priorities for each of the normal mode, power mode, and ECO mode.

  That is, in the hybrid vehicle 20 of the embodiment, when the operation of the engine 22 is stopped, the vehicle speed V is less than the intermittent prohibition vehicle speed Vref, and the required torque Tr * is a torque threshold for stopping the operation of the engine 22. When Tr1 or higher, the engine 22 is prohibited from being stopped and the engine 22 is started (steps S310 and S340). Further, when the power mode is selected as the execution operation mode, the engine start determination threshold Tr1 is set to a value Tr1pwr smaller than the values Tr1nor and Tr1eco for the normal mode and the ECO mode (S50 in FIG. 2). When the ECO mode is selected as the operation mode, the engine start determination threshold Tr1 is set to a value Tr1eco that is larger than the values Tr1nor and Tr1pwr for the normal mode and the power mode (S60 in FIG. 2). As a result, when the power mode that prioritizes the responsiveness of the torque output to the accelerator operation is selected, the normal mode for normal driving and the ECO mode that prioritizes the fuel consumption and the like are selected compared to the case where the engine 22 is selected. Since it is difficult to stop the operation and the engine 22 is started when the operation of the engine 22 is stopped or the operation of the engine 22 is continued to increase, the vibration and noise are slightly increased or the fuel consumption is slightly deteriorated. However, it is possible to quickly obtain a torque for traveling from the engine 22 with good responsiveness, and it is possible to satisfactorily satisfy the high output demand from the driver. Further, when the ECO mode that gives priority to fuel consumption and the like is selected, the operation of the engine 22 is performed as compared with the normal mode for normal driving and the power mode that gives priority to the response of torque output to the accelerator operation. Stopping is likely to be permitted, and when the operation of the engine 22 is not necessary, stopping the operation or continuing the operation stop of the engine 22 may slightly improve traveling performance but improve fuel efficiency. It becomes possible. Further, when the normal mode for normal driving is selected, the engine 22 is operated (started) so that generation of vibration and noise is suppressed and fuel efficiency and driving performance are balanced in general driving. ) And operation stop.

  Further, in the hybrid vehicle 20 of the embodiment, when the engine 22 is operated, the vehicle speed V is less than the intermittent prohibition vehicle speed Vref, and the required torque Tr * is less than the engine stop determination threshold value Tr0 that is a torque threshold value for operating the engine 22. In such a case, the operation stop of the engine 22 is permitted, and the operation of the engine 22 is stopped (steps S180 and S290). The engine stop determination threshold value Tr0 is set smaller than the engine start determination threshold value Tr1 that is a torque threshold value for stopping the operation of the engine 22, and the engine mode is selected when the power mode is selected as the execution operation mode. The stop determination threshold Tr0 is set to a value Tr0pwr that is smaller than the values Tr0nor and Tr0eco for normal mode and ECO mode (S50 in FIG. 2). Thus, by setting the engine stop determination threshold value Tr0 to be smaller than the engine start determination threshold value Tr1, it is possible to suppress frequent start and stop of the engine 22 from being repeated. When the power mode is selected as the execution operation mode, if the engine stop determination threshold value Tr0 is set smaller than when the normal mode or the ECO mode is selected, the power mode is selected. When the engine 22 is being operated, the operation of the engine 22 is unlikely to be stopped, that is, the operation of the engine 22 can be easily continued.

  Further, if the values Tr1nor, Tr1pwr and Tr1eco set as the engine start determination threshold value Tr1 are values obtained by subtracting a predetermined margin from the rated maximum torque of the motor MG2, the margins are made different among the normal mode, the power mode and the ECO mode. In addition, it is possible to permit the engine 22 to be stopped within a range in which a good running torque can be obtained from the motor MG2. Further, in the hybrid vehicle 20 of the embodiment, when the vehicle speed is equal to or higher than the predetermined intermittent prohibition vehicle speed Vref, a torque based on the required torque Tr * is obtained with the operation of the engine 22 regardless of the determination results of steps S180 and S310. Thus, engine 22, motor MG1, and motor MG2 are controlled. Thereby, when the operation of the engine 22 should be continued due to the state of the battery 50, the state of the engine 22, the traveling state of the hybrid vehicle 20, and the like, the operation of the engine 22 is prevented from being stopped. it can.

  In the hybrid vehicle 20 of the embodiment, the ring gear shaft 32a as the axle and the motor MG2 are connected via the reduction gear 35 that reduces the rotational speed of the motor MG2 and transmits it to the ring gear shaft 32a. Instead of 35, for example, a transmission that shifts the rotational speed of the motor MG2 having two shift stages of Hi and Lo or three or more shift stages and transmits it to the ring gear shaft 32a may be employed. Further, although the hybrid vehicle 20 of the embodiment outputs the power of the motor MG2 to the axle connected to the ring gear shaft 32a, the application target of the present invention is not limited to this. That is, the present invention is different from the axle (the axle to which the wheels 39a and 39b are connected) that is connected to the ring gear shaft 32a as in the hybrid vehicle 120 as a modified example shown in FIG. The present invention may be applied to the one that outputs to the wheels 39c and 39d in FIG. Further, the hybrid vehicle 20 of the embodiment outputs the power of the engine 22 to the ring gear shaft 32a as an axle connected to the wheels 39a and 39b via the power distribution and integration mechanism 30. Is not limited to this. That is, the present invention provides an inner rotor 232 connected to the crankshaft of the engine 22 and an outer rotor connected to an axle that outputs power to the wheels 39a and 39b, like a hybrid vehicle 220 as a modified example shown in FIG. 234, and may be applied to a motor including a counter-rotor motor 230 that transmits a part of the power of the engine 22 to the axle and converts the remaining power into electric power.

  Here, the correspondence between the main elements of the above-described embodiments and modifications and the main elements of the invention described in the column of means for solving the problems will be described. In other words, in the above-described embodiment, the engine 22 corresponds to the “internal combustion engine”, the motor MG2 corresponds to the “electric motor”, the battery 50 corresponds to the “power storage means”, and torque output for the accelerator operation compared to the normal mode. A power switch 88 for selecting a power mode that prioritizes the responsiveness of the vehicle and an ECO switch 89 for selecting an ECO mode that prioritizes fuel efficiency and energy efficiency compared to the normal mode and the power mode are “driving mode selection means”. 3 corresponds to “requested torque setting means”, and torque for determining whether or not to stop the operation of the engine 22 by comparison with the requested torque Tr *. FIG. 2 for setting the threshold value to correspond to the operation mode selected as the operation mode for execution The hybrid ECU 70 that executes the determination threshold setting routine corresponds to “threshold setting means”, and the hybrid ECU 70 that executes the processing of steps S180 and S310 of FIG. 3 corresponds to “determination means” and executes the drive control routine of FIG. A combination of the hybrid ECU 70, the engine ECU 24, and the motor ECU 40 that corresponds to the “control means”. The combination of the motor MG1 and the power distribution integration mechanism 30 and the rotor motor 230 correspond to “power power input / output means”, the motor MG1 corresponds to “electric generator motor”, and the power distribution integration mechanism 30 corresponds to “three-axis power”. Corresponding to “type power input / output means”.

  The “internal combustion engine” is not limited to the engine 22 that outputs power by receiving a hydrocarbon-based fuel such as gasoline or light oil, and may be of any other type such as a hydrogen engine. “Electric motor” and “electric generator motor” are not limited to synchronous generator motors such as motors MG1 and MG2, and may be of any other type such as an induction motor. The “storage means” is not limited to a secondary battery such as the battery 50, and may be of any other type such as a capacitor as long as it can exchange electric power with an electric motor or power power input / output means. Absent. The “operation mode selection means” includes a first operation mode for normal traveling, a second operation mode that prioritizes output responsiveness of power for traveling as compared to the first operation mode, and first and first Any combination of the power switch 88 and the ECO switch 89 is possible as long as one of the third operation modes giving priority to fuel consumption over the operation mode 2 can be selected as the execution operation mode. Any other type such as one switch may be used. The “required torque setting means” may be of any type, such as one that sets the required torque without using the vehicle speed V as long as it sets the required torque required for traveling. The “determination means” may be of any other type as long as it compares the required torque with the torque threshold and determines whether or not the internal combustion engine is stopped. The “control means” controls the internal combustion engine and the electric motor so that a torque based on the required torque can be obtained with the operation or stoppage of the internal combustion engine according to the determination result by the determination means under the operation mode for execution. If it does, it is not restricted to the combination of hybrid ECU70, engine ECU24, and motor ECU40, What kind of other types like a single electronic control unit may be used. The “power / power input / output means” is connected to a predetermined axle and connected to the engine shaft of the internal combustion engine so as to be able to rotate independently of the axle. Any combination of the motor MG1 and the power distribution and integration mechanism 30 and any type other than the anti-rotor motor 230 may be used as long as they can input and output power. In any case, the correspondence between the main elements of the embodiments and the modified examples and the main elements of the invention described in the column of means for solving the problems is the same as the means for the embodiments to solve the problems. Since this is an example for specifically explaining the best mode for carrying out the invention described in the column, the elements of the invention described in the column for means for solving the problems are not limited. In other words, the examples are merely specific examples of the invention described in the column of means for solving the problem, and the interpretation of the invention described in the column of means for solving the problem is described in the description of that column. Should be done on the basis.

  The embodiments of the present invention have been described above using the embodiments. However, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the present invention. Needless to say.

  The present invention can be used in the manufacturing industry of hybrid vehicles.

1 is a schematic configuration diagram of a hybrid vehicle 20 according to an embodiment of the present invention. It is a flowchart which shows an example of the determination threshold value setting routine performed by hybrid ECU70 of an Example. It is a flowchart which shows an example of the drive control routine performed by hybrid ECU70 of an Example. It is explanatory drawing which illustrates the map for accelerator opening setting in normal mode, the map for accelerator opening setting in power mode, and the map for accelerator opening setting in ECO mode. It is explanatory drawing which shows an example of the map for request | requirement torque setting. It is explanatory drawing which illustrates the operating curve of the engine 22, the correlation curve of temporary target rotational speed Nettmp, and temporary target torque Tentmp. 4 is a collinear diagram illustrating a dynamic relationship between the number of rotations and torque in a rotating element of the power distribution and integration mechanism 30. It is a schematic block diagram of the hybrid vehicle 120 of the modification. FIG. 11 is a schematic configuration diagram of a hybrid vehicle 220 of a modification example.

Explanation of symbols

  20, 120, 220 Hybrid vehicle, 22 engine, 24 engine electronic control unit (engine ECU), 26 crankshaft, 28 damper, 30 power distribution integration mechanism, 31 sun gear, 32 ring gear, 32a ring gear shaft, 33 pinion gear, 34 carrier , 35 reduction gear, 37 gear mechanism, 38 differential gear, 39a-39d wheels, 40 motor electronic control unit (motor ECU), 41, 42 inverter, 43, 44 rotational position detection sensor, 50 battery, 51 temperature sensor, 52 Electronic control unit for battery (battery ECU), 54 power line, 55 buck-boost converter, 56 system main relay, 57 capacitor, 70 electronic control unit for hybrid (hybrid ECU), 72 CPU, 74 ROM, 76 RAM, 80 ignition switch, 81 shift lever, 82 shift position sensor, 83 accelerator pedal, 84 accelerator pedal position sensor, 85 brake pedal, 86 brake pedal stroke sensor, 87 vehicle speed sensor, 88 power switch, 89 ECO switch, 91 first voltage sensor, 92 second voltage sensor, 93 third voltage sensor, 230 rotor motor, 232 inner rotor, 234 outer rotor, MG1, MG2 motor.

Claims (9)

A hybrid vehicle including an internal combustion engine capable of outputting power for traveling, an electric motor capable of outputting power for traveling, and power storage means capable of exchanging electric power with the motor,
Compared to the first driving mode for normal driving, the second driving mode that prioritizes the output response of driving power compared to the first driving mode, and the first and second driving modes. An operation mode selection means for selecting any one of the third operation modes giving priority to fuel consumption as the execution operation mode;
Requested torque setting means for setting a requested torque required for traveling;
Threshold setting means for setting a torque threshold for determining whether or not to stop operation of the internal combustion engine by comparison with the set required torque so as to correspond to the operation mode selected as the execution operation mode;
A determining means for comparing the set required torque with the set torque threshold to determine whether or not to stop the operation of the internal combustion engine;
The internal combustion engine and the electric motor so that a torque based on the set required torque can be obtained with the operation or the operation stop of the internal combustion engine according to the determination result by the determination means under the execution operation mode. Control means for controlling
A hybrid car with The hybrid vehicle according to claim 1,
The determination means prohibits the operation stop of the internal combustion engine when the set required torque is equal to or greater than a torque threshold for the operation stop of the internal combustion engine when the operation of the internal combustion engine is stopped.
When the second operation mode is selected as the execution operation mode, the threshold setting means uses the first or third torque threshold for the execution operation mode as the execution operation mode when the second operation mode is selected. When the operation mode is selected, the torque threshold for stopping the operation of the internal combustion engine when the third operation mode is selected as the execution operation mode is set smaller than that when the operation mode is selected. A hybrid vehicle that is set larger than when the first or second operation mode is selected as a mode. The hybrid vehicle according to claim 1 or 2,
The determination means permits the operation stop of the internal combustion engine when the set required torque is less than a torque threshold for operation of the internal combustion engine during operation of the internal combustion engine,
The threshold setting means sets a torque threshold for operation of the internal combustion engine to be smaller than a torque threshold for operation stop of the internal combustion engine, and selects the second operation mode as the execution operation mode. In the hybrid vehicle, the torque threshold for operation of the internal combustion engine is set to be smaller than that in the case where the first or third operation mode is selected as the execution operation mode. The hybrid vehicle according to any one of claims 1 to 3,
The torque threshold for stopping the operation of the internal combustion engine is a value obtained by subtracting a predetermined margin from the rated maximum torque of the electric motor, and the margin differs between the first, second and third operation modes. A hybrid car. The hybrid vehicle according to any one of claims 1 to 4,
The control means is configured such that when the vehicle speed is equal to or higher than a predetermined intermittent prohibition vehicle speed, the torque based on the set required torque is obtained with the operation of the internal combustion engine regardless of the determination result by the determination means. A hybrid vehicle for controlling an internal combustion engine and the electric motor. In the hybrid vehicle according to any one of claims 1 to 5,
The required torque setting means includes a required torque setting restriction corresponding to the first operation mode, a required torque setting restriction corresponding to the second operation mode, and a required torque setting restriction corresponding to the third operation mode. , Using the required torque setting constraint corresponding to the execution operation mode, to set the required torque according to the torque request operation by the driver,
The required torque setting constraint corresponding to the second operation mode has a tendency to set the required torque for the same torque request operation larger than the required torque setting constraint corresponding to the first and third operation modes. A hybrid car. The hybrid vehicle according to any one of claims 1 to 6,
Connected to a predetermined axle and the engine shaft of the internal combustion engine and outputs at least part of the power of the internal combustion engine to the axle side with input and output of power and power, and can exchange power with the power storage means Further equipped with a power input / output means.
The electric motor is a hybrid vehicle capable of outputting power to the axle or another axle different from the axle. The hybrid vehicle according to claim 7,
The power drive input / output means includes
A generator motor capable of inputting and outputting power and capable of exchanging electric power with the power storage means;
Connected to three axles, the axle, the engine shaft of the internal combustion engine, and the rotating shaft of the generator motor, and power based on the power input / output to / from any of these three shafts is used as the remaining shaft. A hybrid vehicle including a three-axis power input / output means for inputting and outputting. An internal combustion engine capable of outputting driving power, an electric motor capable of outputting driving power, power storage means capable of exchanging electric power with the motor, a first operation mode for normal driving, and the first Execute either the second operation mode that prioritizes the output responsiveness of the driving power compared to the operation mode or the third operation mode that prioritizes fuel consumption compared to the first and second operation modes. A control method for a hybrid vehicle comprising driving mode selection means for selecting as a driving mode for operation,
(A) setting a torque threshold value for determining whether or not to stop the operation of the internal combustion engine by comparing with a required torque required for traveling so as to correspond to the operation mode selected as the execution operation mode; ,
(B) comparing the required torque with the torque threshold set in step (a) to determine whether or not to stop the operation of the internal combustion engine;
(C) Under the execution operation mode, the internal combustion engine and the internal combustion engine and the Controlling the electric motor;
Control method of hybrid vehicle including

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