JP2013086704A - Hybrid vehicle and control method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To excellently satisfy driver's request to continue running with electric power in which power for running is output only from an electric motor.SOLUTION: When forced execution of motor running is allowed from a warming-up request state of an engine, a heating request state of a vehicle compartment and a state of a battery (S120-S150) and a force EV switch is turned ON by a driver (S160), without executing engine start determination (S190), a motor MG2 is controlled so as to output torque corresponding to requested torque Tr* within the range of the output limit Wout of the battery (S210-S260).

Description

  The present invention relates to a hybrid vehicle including an internal combustion engine capable of outputting traveling power, an electric motor capable of outputting traveling power, and a power storage device capable of exchanging electric power with the electric motor, and a control method thereof.

  Conventionally, as this type of hybrid vehicle, there is known a vehicle equipped with an EV switch for instructing motor traveling that travels only with power from the motor while the operation of the engine is stopped (see, for example, Patent Document 1). ). In this hybrid vehicle, when the EV switch is operated and the motor travels, if the required torque corresponding to the accelerator operation amount becomes equal to or higher than the EV cancel torque corresponding to the vehicle speed, the motor travel instruction by the EV switch is canceled. The engine starts.

JP 2009-67280 A

  In the above-described conventional hybrid vehicle, even if the driver selects the motor travel by operating the EV switch in order to improve the fuel efficiency and the environment, the motor travel is canceled when the required torque reaches the EV cancel torque. For this reason, there is a possibility that the driver's request to continue the motor running cannot be sufficiently met.

  Therefore, the main purpose of the hybrid vehicle and the control method thereof according to the present invention is to better satisfy the driver's request to continue the electric driving in which the driving power is output only from the electric motor.

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

  A hybrid vehicle according to the present invention is a hybrid vehicle including an internal combustion engine capable of outputting traveling power, an electric motor capable of outputting traveling power, and a power storage device capable of exchanging electric power with the electric motor, and travels only from the electric motor. A forced electric travel instruction switch for instructing the forced execution of the electric travel from which the motive power is output, and during the electric travel in a state where the forced execution of the electric travel is instructed, The output characteristic of the driving power with respect to the accelerator operation amount is changed during the electric driving in a state where execution is not instructed.

  In this hybrid vehicle, the electric running in the state where the forced execution of the electric running is instructed by the ON operation of the forced electric running instruction switch, and the electric running in the state where the forced execution of the electric running is not instructed Thus, the output characteristic of the driving power with respect to the accelerator operation amount is changed. As a result, the driver's request to continue the electric driving so that the electric driving is continued even when the accelerator operation amount becomes large (for example, maximum) when the forced execution of the electric driving is instructed. Can be better satisfied.

  In addition, the allowable output torque allowed for the electric motor during the electric driving in the state in which the forced execution of the electric driving is instructed is larger than in the electric driving in the state in which the forced execution of the electric driving is not instructed. May be increased. As a result, it is possible to ensure the running performance and the running distance while the electric running is forcibly executed according to the ON operation of the forced electric running instruction switch.

  Further, when the required power required for the vehicle during the electric traveling in the state where the forced execution of the electric traveling is not instructed exceeds the engine starting power smaller than the allowable discharge power of the power storage device, The internal combustion engine may be started, and during the electric drive in the state where the forced execution of the electric drive is instructed, the start determination of the internal combustion engine is not executed, and the torque is within the allowable discharge power range. The electric motor may be controlled to output. As a result, the output of the driving power relative to the accelerator operation amount during the electric driving in the state where the forced execution of the electric driving is instructed and in the electric driving in the state where the forced execution of the electric driving is not instructed. The characteristics can be changed more appropriately. Further, the allowable output torque allowed for the electric motor is increased in the electric driving in the state where the forced execution of the electric driving is instructed, compared to the electric driving in the state where the forced execution of the electric driving is not instructed. be able to.

  The hybrid vehicle includes a second electric motor, a first element connected to a rotating shaft of the second electric motor, a driving shaft connected to a driving wheel, and a second element connected to the rotating shaft of the electric motor. And a planetary gear having a third element connected to the output shaft of the internal combustion engine, wherein the engine starting power is at least the second for starting the internal combustion engine from the allowable discharge power. You may set by deducting the electric power consumed with the cranking by an electric motor.

  The forced electric travel instruction switch may be configured to instruct the forced execution of the electric travel while being turned on. As a result, when it is desired to continue the electric travel, it is possible to instruct the forced execution of the electric travel by continuing to turn on the forced electric travel instruction switch, and the electric operation can be performed by canceling the on operation of the forced electric travel instruction switch. The instruction for forced execution of traveling can be canceled. As a result, it becomes possible to directly reflect the driver's intention about the forced execution of the electric driving in the control of the hybrid vehicle.

  Furthermore, the hybrid vehicle may further include detection means for detecting another vehicle behind and a notification means for notifying the driver that the other vehicle has approached based on a signal from the detection means. As a result, when there is a possibility that the smooth running of the other vehicle may be hindered by the forced execution of the electric travel, it is possible to prompt the driver to cancel the instruction for the forced execution of the electric travel.

  Further, when the output characteristic of the power for traveling is restored when the instruction for forced execution of the electric traveling is canceled, the output characteristic may be changed gradually. Accordingly, it is possible to improve drivability by suppressing sudden acceleration or the like due to a sudden change in the output characteristics of the driving power before and after the instruction for forced execution of electric driving is canceled.

  The method for controlling a hybrid vehicle according to the present invention includes an internal combustion engine capable of outputting traveling power, an electric motor capable of outputting traveling power, a power storage device capable of exchanging electric power with the electric motor, and traveling power from only the electric motor. Is a hybrid vehicle control method including a forced electric travel instruction switch for instructing forced execution of electric travel in which electric power is output, and during electric travel in a state where the forced execution of electric travel is instructed And the output characteristic of the driving power with respect to the accelerator operation amount is changed during the electric driving in a state where the forced execution of the electric driving is not instructed.

  According to this method, when the forced execution of the electric driving is instructed, the electric driving is continued even if the accelerator operation amount is large (for example, maximum), and the electric driving is continued. It is possible to better satisfy the demands of the person.

1 is a schematic configuration diagram of a hybrid vehicle 20 that is an example of a hybrid vehicle according to the present invention. 4 is a flowchart illustrating an example of an engine stop time drive control routine that is executed when the hybrid vehicle 20 travels in a state where the operation of the engine 22 is stopped. 1 is a schematic configuration diagram illustrating a steering wheel 100 of a hybrid vehicle 20. It is explanatory drawing which shows an example of the map for request | requirement torque setting. 4 is an explanatory diagram illustrating an output characteristic of driving power with respect to an accelerator opening degree Acc in the hybrid vehicle 20; FIG.

  Next, embodiments for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of a hybrid vehicle 20 which is an example of a hybrid vehicle according to the present invention. A hybrid vehicle 20 shown in the figure includes an engine (internal combustion engine) 22 that outputs power using a hydrocarbon fuel such as gasoline and light oil, a single-pinion planetary gear 30, and a motor MG1 that mainly operates as a generator. And a motor MG2 that inputs and outputs power via a transmission 60 to a drive shaft 35 connected to the drive wheels 39a and 39b via a gear mechanism 37 and a differential gear 38.

  Further, hybrid vehicle 20 is connected to an engine electronic control unit (hereinafter referred to as “engine ECU”) 24 for controlling engine 22, inverters 41 and 42 for driving motors MG 1 and MG 2, and inverters 41 and 42. Battery 50, motor electronic control unit (hereinafter referred to as “motor ECU”) 40 that controls motors MG 1 and MG 2 via inverters 41 and 42, and battery electronic control unit (hereinafter referred to as “motor ECU”) 40 that manages battery 50. And a hybrid electronic control unit (hereinafter referred to as “hybrid ECU”) 70 that controls the entire vehicle while communicating with the engine ECU 24, the motor ECU 40, the battery ECU 52, and the like.

  The engine ECU 24 is configured as a microcomputer centered on a CPU (not shown). The engine ECU 24 receives signals from various sensors that are provided to the engine 22 and detect the operating state of the engine 22. The engine ECU 24 receives the intake air amount, fuel injection amount, ignition timing, and the like of the engine 22. A control signal or the like for controlling is output. Further, the engine ECU 24 communicates with the hybrid ECU 70 to control the engine 22 based on a signal from the hybrid ECU 70, a signal from the sensor, and the like, and outputs data related to the operating state of the engine 22 to the hybrid ECU 70 as necessary. .

  Planetary gear 30 is connected to a sun gear (first element) 31 connected to the rotor (rotary shaft) of motor MG1 and to drive shaft 35 and to the rotor (rotary shaft) of motor MG2 via transmission 60. A ring gear (second element) 32 and a planetary carrier (third element) 34 that supports a plurality of pinion gears 33 and is connected to a crankshaft (output shaft) 26 of the engine 22 via a damper (not shown). The transmission 60 can connect and release the rotor of the motor MG2 and the drive shaft 35 and release the connection, and can set the gear ratio between the rotor and the drive shaft 35 in a plurality of stages. Control is performed by the hybrid ECU 70 according to the traveling state of the hybrid vehicle 20 and the like.

  When the motor MG1 functions as a generator that generates power using at least part of the power from the engine 22, the planetary gear 30 transmits the power from the engine 22 transmitted to the planetary carrier 34 to the sun gear 31 and the ring gear 32. Distribute according to gear ratio. In addition, planetary gear 30 integrates the power from engine 22 transmitted to planetary carrier 34 and the power from motor MG1 transmitted to sun gear 31 when motor MG1 functions as an electric motor, and outputs it to ring gear 32. The power output to the ring gear 32 is finally output to the drive wheels 39a and 35b via the drive shaft 35, the gear mechanism 37, the differential gear 38, and the like.

  Motors MG1 and MG2 are configured as well-known synchronous generator motors, and exchange power with battery 50 via inverters 41 and 42, respectively. The power line connecting inverters 41 and 42 and battery 50 is configured as a positive electrode bus and a negative electrode bus shared by inverters 41 and 42, and the power generated by one of motors MG 1 and MG 2 can be consumed by the other. To do. Therefore, the battery 50 is charged / discharged according to the electric power generated or consumed by the motors MG1, MG2, and is not charged / discharged if the balance of electric power is balanced between the motors MG1 and MG2.

  The motor ECU 40 is configured as a microcomputer centering on a CPU (not shown). The motor ECU 40 receives signals from rotational position detection sensors 43 and 44 that detect the rotational positions of the rotors of the motors MG1 and MG2, phase currents applied to the motors MG1 and MG2 detected by a current sensor (not shown), and the like. The motor ECU 40 outputs a switching control signal and the like to the inverters 41 and 42. Further, motor ECU 40 calculates the rotational speeds Nm1 and Nm2 of the rotors of motors MG1 and MG2 based on signals input from rotational position detection sensors 43 and 44. Furthermore, the motor ECU 40 communicates with the hybrid ECU 70, controls the motors MG1 and MG2 based on signals from the hybrid ECU 70, and outputs data related to the states of the motors MG1 and MG2 to the hybrid ECU 70 as necessary.

  The battery 50 is, for example, a nickel hydride secondary battery or a lithium ion secondary battery having a rated output voltage of 200 to 300V. The battery ECU 52 that manages the battery 50 is also configured as a microcomputer centering on a CPU (not shown). The battery ECU 52 includes a terminal voltage Vb from a voltage sensor (not shown) installed between terminals of the battery 50, and a charge / discharge current Ib from a current sensor (not shown) installed in a power line connected to the output terminal of the battery 50. The battery temperature Tb and the like from the temperature sensor 51 installed in the battery 50 are input. Further, the battery ECU 52 calculates the remaining capacity SOC indicating the charging rate of the battery 50 based on the integrated value of the charging / discharging current Ib, or the charge / discharge required power as the target charging / discharging power of the battery 50 based on the remaining capacity SOC. As Pb * (here, the discharge side is positive and the charge side is negative), or the allowable charge power that is the power allowed for charging the battery 50 based on the remaining capacity SOC and the battery temperature Tb The input limit Win and the output limit Wout as the allowable discharge power that is the power allowed for the discharge of the battery 50 are calculated. The battery ECU 52 communicates with the hybrid ECU 70 and the engine ECU 24, and outputs data relating to the state of the battery 50 to the hybrid ECU 70 and the like as necessary.

  The hybrid ECU 70 is configured as a microcomputer centering on the CPU 72, and includes a ROM 74 for storing various programs, a RAM 76 for temporarily storing data, an input / output port and a communication port (not shown), and the like in addition to the CPU 72. As described above, the hybrid ECU 70 communicates with the engine ECU 24, the motor ECU 40, the battery ECU 52, and the like, and exchanges various signals and data with the engine ECU 24, the motor ECU 40, the battery ECU 52, and the like. In addition, the hybrid ECU 70 communicates with a meter electronic control unit (hereinafter referred to as “meter ECU”) 90 that controls a meter display unit (not shown) disposed in the vicinity of the driver's seat of the hybrid vehicle 20, and the meter ECU 90 is necessary. Exchange data.

  Further, the hybrid ECU 70 includes a shift range SR from the shift range sensor 82 that detects an ignition signal from the ignition switch (start switch) 80, a shift range SR corresponding to the operation position (shift position) of the shift lever 81, an accelerator pedal. Accelerator opening (accelerator operation amount) Acc from the accelerator pedal position sensor 84 for detecting the depression amount of 83, brake pedal stroke BS from the brake pedal stroke sensor 86 for detecting the depression amount of the brake pedal 85, and from the vehicle speed sensor 87 The vehicle speed V or the like is input via the input port. In addition, as shown in FIG. 1, an EV priority switch (electric driving priority mode selection switch) 88, a forced EV switch (forced electric driving instruction switch) 89, and a radar sensor unit 95 are connected to the hybrid ECU 70. .

  The EV priority switch 88 is disposed in a switch panel, a steering wheel, or in the vicinity of the steering wheel of the hybrid vehicle 20 (not shown). The operation of the engine 22 is stopped and the driving power is output only from the motor MG2. It is possible to select and cancel an EV priority mode (electric travel priority mode) that preferentially executes motor driving. The on / off signal from the EV priority switch 88 is input to the hybrid ECU 70. When the EV priority switch 88 is turned on, the hybrid ECU 70 sets the EV priority flag Fev to a value 1 and runs the motor for as long as possible. The motor MG2 and the like are controlled in accordance with various control procedures for the EV priority mode determined to be executed. When the EV priority switch 88 is turned off, the hybrid ECU 70 sets the EV priority flag Fev to a value of 0, and controls the engine 22, the motors MG1 and MG2, and the like according to various control procedures for the normal EV mode that are set in advance. Control.

  The compulsory EV switch 89 is for instructing compulsory execution of motor travel in which the operation of the engine 22 is stopped and travel power is output only from the motor MG2. In the present embodiment, the forced EV switch 89 is a push switch, and outputs a signal for instructing the forced execution of the motor running while being turned on (pressed down) by the driving driver. Send to. Further, as shown in FIG. 3, the forced EV switch 89 of the present embodiment is disposed on the steering wheel 100 so that the driver who is driving can easily keep turning on. The radar sensor unit 95 detects an object (another vehicle, that is, a subsequent vehicle) existing behind the vehicle by using radio waves such as millimeter waves or infrared rays, for example, and calculates a distance between the detected subsequent vehicle and the like, The hybrid ECU 70 transmits to the hybrid ECU 70 a signal indicating that the following vehicle has been detected and a signal indicating the distance between the following vehicle and the following vehicle.

  In the hybrid vehicle 20 configured as described above, the required torque Tr * to be output to the drive shaft 35 is calculated based on the accelerator opening Acc and the vehicle speed V, and the torque corresponding to the required torque Tr * is output to the drive shaft. The engine 22 is controlled so as to be output to the engine 35, and torque commands Tm1 * and Tm2 * for the motors MG1 and MG2 are set. In the control mode of the engine 22, the motor MG1 and the motor MG2, the engine 22 is controlled so that power corresponding to the required torque Tr * is output from the engine 22, and all of the power output from the engine 22 is transmitted to the planetary gear 30 and the motor. Torque conversion operation mode for controlling the motors MG1 and MG2 so that the torque is converted by MG1 and MG2 and output to the drive shaft 35, and the power corresponding to the sum of the required torque Tr * and the power required for charging and discharging the battery 50 The engine 22 is controlled so as to be output from the engine 22, and all or part of the power output from the engine 22 with charge / discharge of the battery 50 is torque-converted by the planetary gear 30 and the motors MG1 and MG2. The torque corresponding to the required torque Tr * There are included charge-discharge drive mode for controlling the motors MG1 and MG2 to be outputted to the drive shaft 35. Moreover, in the hybrid vehicle 20, when a predetermined condition is satisfied under the torque conversion operation mode or the charge / discharge operation mode, intermittent operation for automatically stopping and starting the engine 22 is executed. Further, both the EV priority switch 88 and the compulsory EV switch 89 are used in the motor running control mode in which the motor MG2 is controlled so that the engine 22 is stopped and torque corresponding to the required torque Tr * is output to the drive shaft 35. EV mode that is executed when the EV is turned off, EV priority mode that is executed when the EV priority switch 88 is turned on, and forced EV mode that is executed when the forced EV switch 89 is turned on Is included.

  Next, the operation of the hybrid vehicle 20 configured as described above will be described. FIG. 2 is a flowchart showing an example of an engine stop drive control routine executed by the hybrid ECU 70 at predetermined time intervals (for example, every several milliseconds) when the hybrid vehicle 20 travels with the operation of the engine 22 stopped. It is.

  At the start of the engine stop driving control routine of FIG. 2, the hybrid ECU 70 (CPU 72) determines the accelerator opening Acc from the accelerator pedal position sensor 84, the vehicle speed V from the vehicle speed sensor 87, the rotational speed Nm1 of the motors MG1 and MG2, and Nm2, current gear ratio γ of transmission 60, charge / discharge request power Pb * of battery 50, remaining capacity SOC, input limit Win and output limit Wout, warm-up request flag Fwup, heating request flag Fh, EV priority flag Fev and forcing Input processing of data necessary for control such as the value of the EV flag Ffev is executed (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 *, the remaining capacity SOC, the input limit Win, and the output limit Wout of the battery 50 are input from the battery ECU 52 through communication. The The current transmission gear ratio γ of the transmission 60 is a transmission gear ratio set by the transmission 60 at the time of executing the process of step S100 according to, for example, the vehicle speed V, the required torque T *, and the like. It is stored in the storage area.

  The warm-up request flag Fwup is set to a value of 1 when the engine ECU 24 needs to warm up the engine 22, and is set to a value of 0 when the engine 22 has been warmed up. , And input from the engine ECU 24 by communication. The heating request flag Fh is set to a value of 1 when the engine 22 needs to be operated in order to heat the passenger compartment by an air conditioning electronic control unit that controls a passenger compartment air conditioner (not shown), for example. In this case, the value is set to 0, and is input by communication from the air conditioning electronic control unit. The forcible EV flag Ffev is set to a value of 1 while the forcible EV switch 89 is being turned on (depressed) by the hybrid ECU 70, and is set to a value of 0 when the forcible EV switch 89 is not being turned on. It is what is done. Further, in the present embodiment, the hybrid ECU 70 determines the distance between the hybrid vehicle 20 (own vehicle) and the following vehicle based on the signal from the radar sensor unit 95 even when the forced EV switch 89 is turned on. If it is determined that the distance is less than the predetermined distance, the forced EV flag Ffev is set to a value of 0, and a warning display such as “the following vehicle is approaching” is displayed on the meter display unit. A display command for displaying in the area is set, and the set display command is transmitted to meter ECU 90.

  After the data input process in step S100, the hybrid ECU 70 derives and sets the required torque T * corresponding to the accelerator opening Acc and the vehicle speed V input in step S100 from the required torque setting map illustrated in FIG. Then, the required power P * required for the hybrid vehicle 20 (power output device including the engine 22 and the motors MG1 and MG2) is set (step S110). The required power P * is obtained by adding the loss Loss to a value obtained by subtracting the charge / discharge required power Pb * from the product of the required torque T * and the rotational speed Np of the drive shaft 35 (= the rotational speed Nm2 / current speed ratio γ). Can be obtained. Next, the hybrid ECU 70 determines whether or not the warm-up request flag Fwup input in step S100 is a value of 0 (step S120). If the warm-up request flag Fwup is a value of 0, further in step S100. It is determined whether or not the input heating request flag Fh is 0 (step S130).

  When the warm-up request flag Fwup is the value 1 or the heating request flag Fh is the value 1, the hybrid ECU 70 turns on the engine start flag to start the engine 22 (step S280). A display command for displaying a notice display such as “is started in a predetermined display area of the meter display unit” is set, and the set display command is transmitted to the meter ECU 90 (step S290). Then, the hybrid ECU 70 ends this routine and executes an engine start time drive control routine (not shown). The engine start drive control routine starts the engine 22 while cranking the engine 22 by the motor MG1, and cancels torque as a reaction force against the drive torque acting on the drive shaft 35 as the engine 22 is cranked. In this process, the motor MG2 is controlled such that a torque corresponding to the required torque Tr * is output to the drive shaft 35. The engine start flag is turned off when the engine start time drive control routine ends.

  When both the warm-up request flag Fwup and the heating request flag Fh are 0, the hybrid ECU 70 determines whether or not the output limit Wout input in step S100 is greater than or equal to a predetermined threshold value Wref ( If the output limit Wout is equal to or greater than the threshold value Wref and sufficient power can be discharged from the battery 50 in step S140), the remaining capacity SOC input in step S100 is further set to a predetermined threshold value Sref (for example, 40%). It is determined whether or not (step S150). When the remaining capacity SOC is equal to or greater than the threshold value Sref, the hybrid ECU 70 determines whether or not the forced EV flag Ffev input in step S100 is a value 0 (step S160).

  If the forced EV flag Ffev is 0 and the forced EV switch 89 is not turned on (not depressed) by the driver, for example, the required power P * set in step S110 and the previous execution of this routine Accordingly, it is determined whether or not the deviation from the total output power (previous Tm2 ** × Nm2) output from the motor MG2 (power output device including the engine 22 and the motors MG1 and MG2) is included within a predetermined range. (Step S170). Also, if a negative determination is made in step S140 or S150, the determination process in step S170 is executed. When it is determined in step S170 that the deviation is included in the predetermined range, the hybrid ECU 70 uses a relatively small time constant τ0 that is set in advance for the required power P * set in step S110. After performing the smoothing process (normal gradual change process) (step S180), it is determined whether or not the engine 22 is to be started (step S190).

  In step S190, for example, the remaining capacity SOC of the battery 50 input in step S100 is compared with a predetermined threshold, the vehicle speed V input in step S100, for example, depending on the state of the battery 50 (input limit Win), etc. A comparison with the intermittent prohibition vehicle speed, a comparison between the required torque Tr * set at step S110 and a predetermined threshold value, a comparison between the required power P * set at step S110 and the engine starting power, etc. Is called. When the EV priority switch 88 is turned on by the driver and the EV priority mode is selected, the threshold value to be compared with each parameter such as the remaining capacity SOC, the vehicle speed V, the required torque Tr *, and the required power P * When the EV priority switch 88 is turned off by the driver and the EV priority mode is not selected, that is, when the normal EV mode is selected, that is, a predetermined value is set so that the motor travels as long as possible. Used. Thus, when the EV priority mode is selected, it is possible to satisfy the driver's request to continue the motor travel for as long as possible.

  Further, the engine starting power is at least the engine starting power consumed by the cranking by the motor MG1 for starting the engine 22 from the output limit Wout input in step S100, and the vehicle by the passenger compartment air conditioner. It is set by subtracting the air conditioning power required for indoor air conditioning and the power for a predetermined margin. The engine starting electric power is a motor for canceling the electric power input / output by the motor MG1 for cranking the engine 22 and the torque as a reaction force against the driving torque acting on the driving shaft 35 accompanying the cranking of the engine 22. When the vehicle speed V is less than the intermittent prohibition vehicle speed, it is a value on the discharge side (positive value). Furthermore, the power for air conditioning is power for driving a compressor or the like, and is, for example, about several kW or the like, and becomes 0 if the passenger compartment air conditioner is stopped. Therefore, in the present embodiment, the engine starting power is set to a value smaller than the output limit Wout of the battery 50 regardless of the selected state of the EV priority mode.

  As a result of the processing in step S180, the remaining capacity SOC is less than the threshold, the vehicle speed V is greater than or equal to the intermittent prohibition vehicle speed, the required torque Tr * is greater than or equal to the threshold, and the required power P * is greater than or equal to the engine start power. If at least one of these conditions is satisfied, it is determined that the engine 22 should be started, and if all of these conditions are not satisfied, it is determined that the engine 22 should be maintained in a stopped state (step S200). When it is determined that the engine 22 should be started, the hybrid ECU 70 turns on the engine start flag to start the engine 22 (step S280), sets the above-described display command, and transmits the set display command to the meter ECU 90. (Step S290). Then, the hybrid ECU 70 ends this routine and executes the above-described engine start time drive control routine.

  On the other hand, when it is determined in step S190 that the engine 22 should be kept stopped, the hybrid ECU 70 sets the target rotational speed Ne * and the target torque Te * of the engine 22 to values 0 ( In step S210, the torque command Tm1 * for the motor MG1 is set to a value 0 (step S220). Next, the hybrid ECU 70 uses the input / output limits Win and Wout of the battery 50 and the current rotational speed Nm2 of the motor MG2 to output torque limits Tmin and Tmax as upper and lower limits of torque that may be output from the motor MG2. While calculating according to (1) and (2) (step S230), the provisional motor torque Tm2tmp which is a provisional value of torque to be output from the motor MG2 to the drive shaft 35 using the required torque Tr * and the current gear ratio γ. Is calculated according to the following equation (3) (step S240). Then, hybrid ECU 70 sets torque command Tm2 * for motor MG2 to a value obtained by limiting temporary motor torque Tm2tmp with torque limits Tmin and Tmax (step S250). Thus, by setting the torque command Tm2 * for the motor MG2, the torque output to the drive shaft 35 can be limited within the range of the input / output limits Win and Wout of the battery 50.

Tmin = Win / Nm2 (1)
Tmax = Wout / Nm2 (2)
Tm2tmp = Tr * / γ (3)

  If torque commands Tm1 * and Tm2 * for motors MG1 and MG2 are set in this way, hybrid ECU 70 transmits target rotational speed Ne * and target torque Te * of engine 22 to engine ECU 24 and torques of motors MG1 and MG2. Commands Tm1 * and Tm2 * are transmitted to the motor ECU 40 (step S260), and this routine is temporarily terminated. The engine ECU 24 that has received the target rotational speed Ne * and the target torque Te * from the hybrid ECU 70 maintains the engine 22 in a stopped state. The motor ECU 40 that has received the torque commands Tm1 * and Tm2 * from the hybrid ECU 70 switches 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 *. Switching control of the element is performed. That is, hybrid ECU 70, engine ECU 24, and motor ECU 40 function as a control device that controls engine 22 and motors MG1 and MG2 in accordance with accelerator opening Acc.

  By performing the processing as described above, in hybrid vehicle 20, the motor MG 2 (power output device including engine 22 and motors MG 1 and MG 2) is used during motor traveling in the normal EV mode or EV priority mode. As shown by a broken line in FIG. 5, the total output power of the engine is limited to a range of engine starting power that is smaller than the output limit Wout of the battery 50. That is, when the accelerator opening Acc is increased to some extent during motor running under the normal EV mode or the EV priority mode, for example, the required power P * becomes equal to or higher than the engine start power, and the engine 22 is started. As indicated by the solid line, traveling power corresponding to the accelerator opening Acc is output from both the engine 22 and the motor MG2. That is, even if the accelerator opening degree Acc reaches 100% during the motor traveling in the normal EV mode or the EV priority mode, the motor traveling is not continued as it is.

  On the other hand, a positive determination is made in all of steps S120 to S150, and if it is determined in step S160 that the forced EV flag Ffev has a value of 1 and the driver is turning on the forced EV switch 89, that is, When the forced running of the motor drive is permitted from the warming-up request state of the engine 22, the heating requirement of the passenger compartment, and the state of the battery 50, and the driver is turning on the forced EV switch 89, the hybrid ECU 70 Skips the processes in steps S170 to S200 described above, and executes the processes in step S210 and subsequent steps. That is, in the hybrid vehicle 20, when the driver is instructed to forcibly execute the motor travel, and the forced execution of the motor travel is permitted, the start determination of the engine 22 as described above is performed. Instead, the motor MG2 is controlled to output a torque corresponding to the required torque Tr * to the drive shaft 35 within the range of the output limit (allowable discharge power) Wout of the battery 50.

  As described above, in the hybrid vehicle 20, when the forced EV switch 89 is turned on by the driver, that is, when the motor travel is performed under the forced EV mode, the engine is allowed to be forcibly executed. 22 is not determined, and the total output power from the motor MG2 (power output device including the engine 22 and the motors MG1 and MG2) is larger than the engine start power described above as shown by the dotted line in FIG. It is limited within the range of the output limit Wout. As a result, in the hybrid vehicle 20, the total output power from the motor MG2 is limited within the range of the output limit Wout of the battery 50 while the forced execution of the motor travel is allowed, as shown in FIG. Even if the accelerator opening degree Acc reaches 100%, the motor travel can be continuously executed. That is, as can be seen from FIG. 5, in the hybrid vehicle 20, when the motor is running under the forced EV mode (see the dotted line in FIG. 5), the forced execution of the motor running is not instructed, that is, the normal EV mode. Alternatively, when the motor travels under the EV priority mode (see the broken line in FIG. 5), the output characteristics of the travel power with respect to the accelerator opening Acc are changed, and when the motor travels under the forced EV mode, The allowable output torque allowed for the motor MG2 (allowable output torque for the same vehicle speed V (rotation speed Nm2)) is increased as compared to when the motor travels in the EV mode or the EV priority mode.

  If a negative determination is made in step S170, the hybrid ECU 70 uses the time constant τ corresponding to the accelerator opening Acc input in step S100 to the required power P * set in step S110. (Step S270), and the processing after Step S190 described above is executed. The time constant τ used in the annealing process in step S270 is basically larger than the time constant τ0 used in step S180, and is set larger as the accelerator opening Acc is larger. Thereby, for example, when the on-operation of the forced EV switch 89 is released while the accelerator pedal 83 is largely depressed, the total output power output from the motor MG2 in accordance with the previous execution of this routine is returned to step S110. Even if the required power P * set in this way becomes significantly large, a rapid increase in the power output from the power output device including the engine 22 and the motors MG1 and MG2, that is, the torque output to the drive shaft 35, is suppressed. It becomes possible to suppress sudden acceleration of the automobile 20.

  As described above, in the hybrid vehicle 20 of the present embodiment, when the motor EV is instructed to be forcibly executed by turning on the forced EV switch 89, that is, in the motor EV mode, the motor travel When the forced execution of the vehicle is not instructed, that is, when the motor travels in the normal EV mode or the EV priority mode, the output characteristics of the traveling power with respect to the accelerator opening Acc are changed. As a result, when the forced execution of the motor travel is instructed (when the forced EV mode is selected), the motor travel is continued even when the accelerator opening Acc is large, that is, 100%. It is possible to better satisfy the driver's request to continue the motor running.

  In hybrid vehicle 20, the allowable output torque allowed for motor MG2 is increased when the motor is running under the forced EV mode, compared to when the motor is running under the normal EV mode or the EV priority mode. . As a result, it is possible to ensure travel performance and travel distance while the motor travel is forcibly executed in response to the on operation of the forced EV switch 89.

  Furthermore, in the hybrid vehicle 20, the required power P * required for the vehicle (power output device) during motor driving in the normal EV mode or EV priority mode is at least the engine starting power from the output limit Wout of the battery 50. When the engine starting power obtained by subtracting is exceeded, the engine 22 is started. On the other hand, when the motor travels in the forced EV mode, the engine 22 is not determined to start, and the torque corresponding to the required torque Tr * is within the range of the output limit Wout that is larger than the engine starting power. Is controlled so as to output. This makes it possible to more appropriately change the output characteristics of the driving power with respect to the accelerator opening Acc between when the motor travels under the forced EV mode and when the motor travels under the normal EV mode or EV priority mode. can do. In addition, by distributing the engine starting power required for engine starting to the traveling power, the motor is driven in the forced EV mode, compared with the motor traveling in the normal EV mode or the EV priority mode. The allowable output torque allowed for MG1 and MG2 can be increased.

  In the above embodiment, the forced EV switch 89 is configured to instruct the forced execution of the motor travel while being turned on. As a result, when it is desired to continue the motor travel, it is possible to instruct the forced execution of the motor travel by continuing to turn on the forced EV switch 89, and by canceling the on operation of the forced EV switch 89, Forced execution instructions can be released. As a result, it is possible to directly reflect the driver's intention about the forced execution of the motor running in the control of the hybrid vehicle 20. However, the forcible EV switch 89 may be configured to instruct forcible execution of motor travel by a single ON operation. In this case, for example, the forced travel of the motor is performed after a predetermined time has elapsed. The automatic execution may be automatically canceled on the vehicle (control device) side.

  In addition, the hybrid vehicle 20 of the above embodiment includes a radar sensor unit 95 that detects the following vehicle, and the hybrid ECU 70 has an inter-vehicle distance between the hybrid vehicle 20 (own vehicle) and the following vehicle that is less than a predetermined distance. Then, the compulsory EV flag Ffev is set to a value of 0, and a display command is given to the meter ECU 90 so that the driver is informed through the meter display unit that the following vehicle has approached. As a result, when there is a risk that the smooth running of the following vehicle may be hindered by the forced execution of the motor running, the driver is prompted to cancel the instruction of the forced running of the motor running, and the hybrid vehicle 20 (own vehicle) ) And the following vehicle can be easily secured. However, if the driver is informed of the approach of the succeeding vehicle, the driver is considered to execute the vehicle operation according to the notification content, so the distance between the hybrid vehicle 20 and the succeeding vehicle is less than a predetermined distance. It may be omitted to set the forced EV flag Ffev to a value of 0 at the stage when the value becomes zero, that is, to automatically cancel the instruction to forcibly execute motor travel.

  Furthermore, in the hybrid vehicle 20, when the output characteristic of the driving power is restored in response to the cancellation of the instruction to forcibly execute the motor driving, the output characteristic is gradually changed (step S270). Accordingly, it is possible to improve drivability by suppressing sudden acceleration or the like due to a sudden change in the output characteristics of the driving power before and after the instruction to forcibly execute motor driving is canceled.

  Note that the output characteristics of the driving power with respect to the accelerator opening Acc can be changed between the motor traveling under the forced EV mode and the motor traveling under the normal EV mode or the EV priority mode. The control routine for increasing the allowable output torque allowed for the motor MG2 when the motor is running under the EV mode is larger than that when the motor is running under the normal EV mode or the EV priority mode. Any control routine is applicable as long as the motor travel is continued even when the accelerator opening Acc is large (100%) during motor travel under the forced EV mode. Can be adopted. Further, when starting the engine 22 in step S190 of FIG. 2, the required travel power (required torque T * and the rotational speed Np of the drive shaft 35) required for traveling of the hybrid vehicle 20 instead of the above-described required power P *. And the engine starting power may be compared. Further, the hybrid vehicle 20 includes a motor MG1 (second electric motor), a motor MG2, a sun gear 31 connected to the rotor of the motor MG1, a drive shaft 35 connected to the drive wheels 39a and 39b, and a motor MG2. Although it includes a planetary gear 30 having a ring gear 32 connected to the rotor and a planetary carrier 34 connected to the crankshaft 26 of the engine 22, the hybrid vehicle to which the present invention is applied is not limited to this. . That is, the hybrid vehicle according to the present invention may be configured as a so-called single-motor hybrid vehicle. Further, instead of the transmission 60, a simple reduction gear mechanism may be employed.

  Here, the correspondence between the main elements of the above embodiment and the main elements of the invention described in the column of means for solving the problems will be described. That is, the engine 22 that can output the traveling power to the drive shaft 35 via the ring gear 32 of the planetary gear 30 corresponds to the “internal combustion engine”, and the motor MG2 that can output the traveling power to the drive shaft 35 becomes the “electric motor”. The battery 50 that can exchange electric power with the motor MG2 corresponds to the “power storage device”, the forced EV switch 89 for instructing the forced execution of the motor traveling corresponds to the “forced electric traveling instruction switch”, and the subsequent The radar sensor unit 95 that detects the vehicle corresponds to “detection means”, and the combination of the hybrid ECU 70, the meter ECU 90, and the meter display unit corresponds to “notification means”.

  However, the correspondence between the main elements of the above embodiment and the main elements of the invention described in the column of means for solving the problem is described in the column of means for solving the problem by the embodiment. Since the embodiment for carrying out the invention is an embodiment for specifically explaining the invention, the elements of the invention described in the column of means for solving the problems are not limited. That is, the above embodiment is merely a specific form of the invention described in the section for solving the problem, and the interpretation of the invention described in the section for solving the problem is This should be done based on the description in the column.

  Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and it goes without saying that various modifications can be made without departing from the scope of the present invention. .

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

  1 Hybrid Vehicle, 22 Engine, 24 Engine Electronic Control Unit (Engine ECU), 26 Crankshaft, 28 Damper, 30 Planetary Gear, 31 Sun Gear, 32 Ring Gear, 33 Pinion Gear, 34 Planetary Carrier, 35 Drive Shaft, 37 Gear Mechanism, 38 Differential gear, 39a, 39b Drive wheel, 40 Motor electronic control unit (motor ECU), 41, 42 Inverter, 43, 44 Rotation position detection sensor, 50 battery, 51 Temperature sensor, 52 Battery electronic control unit (battery ECU) , 60 transmission, 70 hybrid electronic control unit (hybrid ECU), 72 CPU, 74 ROM, 76 RAM, 81 shift lever, 82 shift range sensor, 83 accelerator pedal 84 accelerator pedal position sensor, 85 brake pedal, 86 brake pedal stroke sensor, 87 vehicle speed sensor, 88 EV priority switch, 89 forced EV switch, 90 meter electronic control unit (meter ECU), 95 radar sensor unit, 100 steering wheel , MG1, MG2 motors.

Claims (8)

In a hybrid vehicle including an internal combustion engine capable of outputting traveling power, an electric motor capable of outputting traveling power, and a power storage device capable of exchanging electric power with the electric motor,
A forced electric travel instruction switch for instructing forced execution of electric travel in which traveling power is output only from the electric motor;
Output characteristics of the driving power with respect to the accelerator operation amount during the electric driving in the state where the forced execution of the electric driving is instructed and during the electric driving in the state where the forced execution of the electric driving is not instructed A hybrid vehicle characterized in that is changed. The hybrid vehicle according to claim 1,
The allowable output torque allowed for the electric motor is increased in the electric running in the state where the forced execution of the electric running is instructed compared to the electric running in the state where the forced execution of the electric running is not instructed. A hybrid vehicle characterized by being made. In the hybrid vehicle according to claim 1 or 2,
When the required power required for the vehicle during the electric driving in the state where the forced execution of the electric driving is not instructed exceeds the engine starting power smaller than the allowable discharge power of the power storage device, the internal combustion engine Is started, and during the electric running in a state where the forced running of the electric running is instructed, the start determination of the internal combustion engine is not executed, and the torque is output within the allowable discharge power range. A hybrid vehicle in which an electric motor is controlled. In the hybrid vehicle according to claim 3,
A second electric motor, a first element connected to the rotating shaft of the second electric motor, a driving shaft connected to a driving wheel, a second element connected to the rotating shaft of the electric motor, and an output of the internal combustion engine A planetary gear having a third element connected to the shaft,
The hybrid vehicle according to claim 1, wherein the engine starting power is set by subtracting at least power consumed by cranking by the second electric motor for starting the internal combustion engine from the allowable discharge power. In the hybrid vehicle according to any one of claims 1 to 4,
The hybrid vehicle, wherein the forced electric travel instruction switch is configured to instruct the forced execution of the electric travel while being turned on. In the hybrid vehicle according to any one of claims 1 to 5,
Detection means for detecting other vehicles behind,
A hybrid vehicle, further comprising: a notification unit that notifies a driver that the other vehicle has approached based on a signal from the detection unit. The hybrid vehicle according to any one of claims 1 to 6,
A hybrid vehicle characterized in that the output characteristic is gradually changed when the output characteristic of the driving power is restored in response to the cancellation of the instruction for forced execution of the electric traveling. An internal combustion engine capable of outputting traveling power, an electric motor capable of outputting traveling power, a power storage device capable of exchanging electric power with the electric motor, and forced execution of electric traveling in which traveling power is output only from the electric motor A hybrid vehicle control method including a forced electric travel instruction switch for instructing
Output characteristics of the driving power with respect to the accelerator operation amount during the electric driving in the state where the forced execution of the electric driving is instructed and during the electric driving in the state where the forced execution of the electric driving is not instructed A control method for a hybrid vehicle, characterized in that

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