JP2005278293A - Hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hybrid vehicle suppressing fuel consumption by suppressing unnecessary accelerator operation while compensating for deficiency of travel driving force when a large travel driving force is required under low speed traveling state at the time starting a vehicle. <P>SOLUTION: Operation of a motor 2 is controlled to output a target torque when a hybrid vehicle performs powering operation by setting the target torque when powering operation is carried out in the state wherein the accelerator operation amount increases or the charged state of a battery 4 becomes higher, and under low speed state, the vehicle speed is lower than a set speed as compared with the state where the vehicle speed is higher than the set speed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention includes an engine and an electric motor that rotates integrally with the engine as a power source, and is configured to drive the traveling device. The control unit that controls the driving state of the vehicle performs the power running operation and the regenerative operation. And a hybrid vehicle configured to control the operation of the electric motor.

  In the hybrid vehicle having the above configuration, conventionally, the required driving force required for traveling is obtained based on the information on the accelerator operation amount, and the battery mounted on the vehicle for supplying electric power to the electric motor is obtained. When the state of charge is higher than the set value, the power running operation by the electric motor is executed (see, for example, Patent Document 1).

  Incidentally, the exemplified Patent Document 1 does not describe in detail the configuration for obtaining the target value of the power running torque when the electric motor performs the power running operation, but requires a large required driving force when the accelerator operation amount is large. Therefore, the target value of the power running torque of the electric motor is generally set to a larger value as the accelerator operation amount is larger, and when the battery is charged, the target value is supplied to the electric motor. Since the electric power can be increased, the target value of the power running torque of the electric motor is generally set to a larger value as the state of charge of the battery is larger.

JP 11-299004 A

  However, in the above-described conventional configuration, even when the vehicle is started from a state where the vehicle is stopped and then accelerated, the target value of the power running torque of the electric motor is the information on the accelerator operation amount. Since it is calculated | required from the charge condition of a battery, a driver | operator may feel lack of driving force at the time of start of a vehicle.

  In other words, when driving a vehicle, after starting the vehicle from a stopped state and accelerating to a desired vehicle speed, the vehicle then switches to a steady driving state in which the vehicle is driven to maintain the vehicle speed. However, in the steady running state as described above, the rotational speed of the engine is also increased, and the driving force required for running can be obtained by the power of the engine. When the vehicle speed is low, the engine often has a low rotational speed and a low output. Therefore, as described above, the electric motor obtained from the information on the accelerator operation amount and the state of charge of the battery With the power running torque, if the accelerator operation amount is small, the driving force may be insufficient and the vehicle may not start smoothly.

  Therefore, at the time of starting of such a vehicle, in order to perform the power running operation by the electric motor with a sufficient power running torque, the driver performs the accelerator operation so that the accelerator operation amount becomes a sufficiently large value. There is a need.

  Therefore, in the above-described conventional configuration, when starting the vehicle, the driver must always perform the accelerator operation so that the accelerator operation amount becomes a sufficiently large value, and the frequency of operating the accelerator operation amount to the large side increases. As a result, the amount of fuel supplied to the engine increases. As a result, there is a disadvantage that the unique advantage of the hybrid vehicle that reduces the fuel consumption of the engine is impaired.

  An object of the present invention is to suppress the fuel consumption of an engine to a small amount while compensating for a shortage of driving force when the vehicle is traveling at a low speed such as when the vehicle is started. This is to provide a hybrid vehicle that enables the vehicle.

  A first characteristic configuration of the present invention is configured to drive a traveling device by including an engine and an electric motor that rotates integrally with the engine as a power source, and a control unit that controls a driving state of the vehicle includes power running operation and regeneration. In the hybrid vehicle configured to control the operation of the electric motor so as to execute the operation, the target torque when the control unit performs the power running operation increases as the accelerator operation amount increases. The higher the state of charge of the battery is, the larger it is, and when the vehicle speed is in the low speed state, the battery is set to be larger than in the high speed state.

  According to the first characteristic configuration, the power running is increased so that the accelerator operation amount increases, the battery charging state increases, and the vehicle speed increases when the vehicle speed is low and when the vehicle speed is low. A target torque for operation is set. That is, as the accelerator operation amount increases, the target torque for powering operation increases, so when the accelerator operation amount is large and the driver requests a large driving force, a large torque is output by the electric motor. Power running can be operated. In addition, the target torque for powering operation increases as the state of charge of the battery increases. In other words, the target torque decreases as the state of charge of the battery decreases. Since there is no risk of a significant drop, there is no disadvantage that the battery charge state becomes low and the subsequent driving of the vehicle is hindered.

  When the vehicle speed is low, the target torque for performing the power running operation is larger than when the vehicle is in the high speed state. Therefore, the vehicle speed is reduced as in the case where the vehicle is started from a state where the vehicle is stopped. When the engine speed is low and the engine speed is low, the target torque is set to be large based on the vehicle speed information regardless of the amount of accelerator operation.

  Therefore, when the vehicle speed is low and the engine rotational speed is low, the power running operation by the electric motor can be performed with a large power running torque without increasing the accelerator operation amount. As described above, a hybrid vehicle capable of compensating for the shortage of the driving force in a case where a large driving force is required in a low-speed driving state and capable of suppressing the fuel consumption of the engine is provided. I was able to do it.

  In addition to the first feature configuration, the second feature configuration of the present invention is a process in which the control means obtains a target torque when performing the power running operation. Torque output rate obtained in a state where the higher the vehicle is, the torque variation coefficient obtained in a state where the vehicle speed is lower than that in the high speed state when the vehicle speed is low, and the torque output rate is maximum and the The target torque is obtained based on information on each maximum torque set in accordance with the rotation speed of the electric motor as a value when the torque fluctuation coefficient is in the high speed state.

  According to the second characteristic configuration, when obtaining the target torque for performing the power running operation, the control means obtains the torque output rate in such a state that the larger the accelerator operation amount is, the larger the battery charging state is. . This torque output rate can be obtained from, for example, the respective detection results of the accelerator operation amount and the battery charge state, preset map data, arithmetic expressions, and the like. In addition, the torque variation coefficient is obtained in a state where the vehicle speed is lower when the vehicle speed is lower than when the vehicle speed is higher. The torque fluctuation coefficient can be obtained from, for example, a vehicle speed detection result and preset map data, an arithmetic expression, or the like.

  And the said target torque is calculated | required based on each information of the said maximum torque corresponding to the said torque output rate, the said torque fluctuation coefficient, and the rotational speed of the electric motor at that time. This maximum torque is a value set in advance corresponding to the rotational speed of the electric motor as a value when the torque output rate is the maximum and the torque fluctuation coefficient is in the high speed state.

  Therefore, when the vehicle starts and runs and the vehicle speed is in a high speed state, the power running operation can be performed with an appropriate torque according to the accelerator operation amount and the state of charge of the battery. When the vehicle is in a low speed state, even if the accelerator operation amount is small, the power running operation can be performed with a large torque by the electric motor, and the shortage of the driving force can be compensated.

  According to a third feature configuration of the present invention, in addition to the first feature configuration or the second feature configuration, the control means sets a threshold for start determination in which the accelerator operation amount is set in advance according to the rotation speed of the engine. If it exceeds, it is configured to execute the power running operation, and the accelerator operation amount is set to be lower than the start determination threshold when the engine rotation speed is the same according to the engine rotation speed. The power running operation is stopped when it falls below a threshold value.

  According to the third characteristic configuration, when the accelerator operation amount exceeds a start determination threshold value set in advance according to the engine rotation speed, a power running operation is performed by the electric motor, and the accelerator operation amount is the same as the engine rotation speed. The power running operation is stopped when the value falls below the stop determination threshold set lower than the start determination threshold.

  Thus, based on the information of the accelerator operation amount that is the command information for driving operated by the driver, it is switched between a state where the power running operation is executed and a state where the power running operation is not executed. The operation of the electric motor can be controlled as much as possible in accordance with the driver's intention.

Hereinafter, embodiments of a hybrid vehicle according to the present invention will be described with reference to the drawings.
As shown in FIG. 1, the hybrid vehicle is directly connected so that the travel drive engine 1 and the travel drive electric motor 2 rotate integrally. In other words, the electric motor 2 for driving driving is provided in a state directly connected to the output shaft 1a of the engine 1 for driving driving, and driving is performed by driving the left and right wheels 3 as a driving device with these powers. A drive unit KU as means is configured. The electric motor 2 is connected to the output shaft 1a of the engine 1 so that the rotor 2a rotates integrally with the same axis, and the stator 2b surrounding the outer periphery of the rotor 2a is fixed to a vehicle body support portion (not shown) in a fixed position. It becomes the structure supported.

  The electric motor 2 is configured to start the engine 1 by applying a driving force to the output shaft 1a in a state where the operation of the engine 1 is stopped. The output shaft 1a can be switched between a power running state in which a driving force in the same direction as the engine rotation direction is applied to assist or assist the power, and a regenerative state in which the driving force is applied from the output shaft 1a. It is configured. That is, the electric motor 2 is switched to a power running state in which torque is output in the same direction as the rotation direction with respect to the output shaft 1a that is rotationally driven by the engine 1, so that the engine 1 can output the desired driving force. It is the structure which can assist the motive power with respect to the output of the engine 1 so that it may become a low fuel consumption state. This operating state corresponds to the power running operation. Further, when the traveling speed is reduced, the electric motor 2 is in a regenerative state, and the battery 4 can be charged with the regenerative electric power obtained by generating the driving force from the output shaft 1a. It has become. This operating state corresponds to the regenerative operation.

  The power of the drive unit KU is transmitted to the transmission 6 and is transmitted to the left and right wheels 3 via the differential mechanism 7 after being shifted by a gear-type automatic transmission mechanism inside the transmission 6.

Next, a control configuration in this hybrid vehicle will be described.
As shown in FIGS. 1 and 2, a vehicle control unit 8 that manages and manages the overall operation of the vehicle, a motor control unit 9 that controls the operation of the electric motor 2 based on control information from the vehicle control unit 8, An engine control unit 12 that automatically adjusts the output of the engine 1 based on the control information from the vehicle control unit 8, specifically, the throttle opening of the electronic throttle valve 10 and the fuel injection amount by the injector 11, is provided. A potentiometer type accelerator operation amount detection sensor S1 for detecting the operation amount of the operation tool 13, a switch type brake operation detection sensor S2 for detecting whether or not the brake operation tool 14 is depressed, the rotational speed of the electric motor 2, In other words, the rotational speed sensor S3 as rotational speed detection means for detecting the rotational speed of the output shaft 1a of the engine 1 and the rotation of the axle of the wheel 3 are detected. Based on the speed, a vehicle speed sensor S4 that is an example of a running state detecting means that detects a vehicle speed as a running state of the vehicle, a shift position sensor S5 that detects the position of the shift position lever 17, and a state of charge SOC of the battery 4 are detected. Various detection information from the charging state detection unit S6 and the like is input to the vehicle control unit 8.

  As shown in FIG. 3, the motor control unit 9 controls the driving power supplied to the electric motor 2 by converting the DC power supplied from the battery 4 into three-phase AC power, or by regenerative operation. Inverter 28 that controls the regenerative power that is generated at 2 and supplied to battery 4, and the pulse drive signal that is pulse-width modulated (PWM) based on control information from vehicle control unit 8 is supplied to each switching transistor in inverter 28. PWM control circuit 29 and the like that are supplied to each of the base terminals of the battery, and by adjusting the magnitude of the current flowing through the electric motor 2 and the frequency of the alternating current, the drive torque and the rotational speed can be adjusted, and the battery The regenerative power charged to 4 can be adjusted.

  When a description is given of a configuration for generating mechanical braking force by operating the mechanical braking means KS by the brake operating tool 14, when the brake operating tool 14 is operated by a driver's stepping operation, A master cylinder 15 having a known configuration that generates a hydraulic operating force for braking corresponding to the stepping operating force is provided, and the vicinity of the wheel 3 is generated by the hydraulic operating force output from the master cylinder 15 through the hydraulic oil supply passage 15a. The vehicle body is braked by operating a friction braking device 16 provided on the vehicle. Such a mechanical braking means KS is configured to be adjustable so that the hydraulic operating force, that is, the mechanical braking force increases as the operating force of the driver with respect to the brake operating tool 14 increases. .

  The position of the shift position lever 17 includes “P” (parking position), “R” (reverse travel position), “N” (neutral position), and “D” (forward travel position). The switching operation is appropriately performed according to the situation.

  The vehicle control unit 8 detects the detection information of the shift position sensor S5, the detection information of the accelerator operation amount detection sensor S1, the detection information of the vehicle speed sensor S4, and the charge state of the battery 4 detected by the charge state detection unit S6. Based on the information and the like, the motor control unit 9 and the engine control unit 12 are configured to command control information. The motor control unit 9 and the engine control unit 12 operate the electric motor 2 and the engine 1 based on the command information. Is configured to control. Therefore, the vehicle control unit 8, the motor control unit 9, and the engine control unit 12 constitute a control means H that controls the driving state of the vehicle.

Next, control of the engine 1 and the electric motor 2 by the control means H will be described.
When the shift position lever 17 is at “P” (parking position) or “N” (neutral position), the engine 1 is basically stopped and the power running operation and the regenerative operation by the electric motor 2 are not performed. However, when the state of charge of the battery 4 drops below the set amount and the battery 4 needs to be charged, the engine 1 is operated and the power of the engine 1 is generated by the regenerative operation of the electric motor 2. The operation of the engine 1 and the electric motor 2 is controlled so as to charge the battery 4 with electric power.

  Further, when the shift position lever 17 is operated to “D” (forward travel position) and the forward direction is commanded as the vehicle body traveling direction, the control means H is operated by depressing the accelerator operating tool 13 and the vehicle body. When the engine 1 is stopped at that time, the electric motor 2 is rotated to start the engine 1, and when the vehicle body travels forward, the output of the engine 1 is adjusted according to the accelerator operation amount, As will be described later, the electric motor 2 is configured to execute control so as to execute a power running operation and a regenerative operation. Even when the shift position lever 17 is operated to “D” (forward travel position), the vehicle stops traveling in a state where the accelerator operation is not performed, and the charge state of the battery 4 is equal to or higher than the set value. When the engine is in a high state, it is configured to execute idle stop control for stopping the engine 1. By executing the idle stop control in this way, the fuel consumption of the engine 1 is minimized.

  When the shift position lever 17 is operated to “R” (reverse travel position) and the reverse direction is commanded as the vehicle body travel direction, the output of the engine 1 is adjusted according to the accelerator operation amount. However, for the electric motor 2, neither power running operation nor regenerative operation is performed.

Next, the power running operation and regenerative operation of the electric motor 2 by the control means H will be described.
The power running operation and the regenerative operation of the electric motor 2 are performed by obtaining a target torque based on various types of information described later and controlling the operation of the electric motor 2 so as to generate the obtained target torque. In other words, in the power running operation, the control information corresponding to the target value of the power running torque is PWM controlled so that the electric motor 2 outputs the target value of the power running torque in the same direction as the rotation direction of the engine 1. A pulse signal corresponding to the target torque for power running is applied from the PWM control circuit 29 to the base terminal of each switching transistor of the inverter 28, and the electric motor 2 assists the engine 1 with the target torque. become. In the regenerative operation, control information corresponding to the target value of the regenerative torque is supplied to the PWM control circuit 29 so that the electric motor 2 outputs the target value of the regenerative torque in the direction opposite to the rotation direction of the engine 1. The PWM control circuit 29 applies a pulse signal corresponding to the target torque for regeneration to the base terminal of each switching transistor of the inverter 28, so that the electric motor 2 has a reverse torque with respect to the engine 1, that is, The regenerative braking force is applied. Then, the electric motor 2 is driven by the power of the engine 1 to act as a generator, and the battery 4 is charged in a state where the inverter 28 is changed and adjusted to the regenerative power corresponding to the regenerative braking force.

  The control means H is configured to execute a power running operation when the accelerator operation amount exceeds a preset threshold value for start determination according to the engine rotation speed, and the accelerator operation amount is set to the engine rotation speed. Accordingly, the power running operation is stopped when the rotation speed of the engine falls below a stop determination threshold set lower than the start determination threshold at the same time.

  In addition, the control means H increases the target torque when performing the power running operation as the accelerator operation amount increases, increases as the battery is charged, and increases when the vehicle speed is low. It is comprised so that it may set so that it may become larger than. That is, as a process for obtaining the target torque when performing the power running operation, the torque output rate obtained when the accelerator operation amount is larger and the battery charging state is larger, and the vehicle speed is low when the vehicle speed is low. The torque fluctuation coefficient obtained in a state larger than that in the state and the value when the torque output rate is maximum and the torque fluctuation coefficient is in the high speed state are set according to the rotation speed of the electric motor. The target torque is determined based on information on each of the maximum torques.

  Hereinafter, the control operation of the electric motor 2 of the control means H in a state where the shift position lever 17 is operated to “D” (forward travel position) will be described based on the control flowchart shown in FIG.

  First, a motor operating condition is determined as to whether the electric motor 2 performs a power running operation or a regenerative operation (step 1). When the description of the determination of the motor operating condition is added, as shown in FIG. 5, the accelerator operation amount detected by the accelerator operation amount detection sensor S1 is set in advance in map data with respect to the engine rotation speed at that time. When the powering start threshold ACH is exceeded, it is determined that the powering operation condition is satisfied. Then, as shown in FIG. 5, the accelerator operation amount detected by the accelerator operation amount detection sensor S <b> 1 is set according to the rotation speed of the engine 1 than the threshold value ACH for start determination when the rotation speed of the engine 1 is the same. When the state is lower than the start determination threshold ACH set in advance in the map data as a value lower by the amount, the power running operation condition is determined not to be satisfied.

  When it is determined that the power running operation condition is satisfied, when the regenerative operation is performed at that time, the output processing of the regenerative torque is stopped (steps 2 and 3), and the motor torque is based on the information on the accelerator operation amount. An output rate A (an example of torque output rate) is obtained (step 4). The method of obtaining the motor torque output rate A will be described. As shown in FIG. 6, the change characteristic of the motor torque output rate A, which is the change rate of the power running torque when the accelerator operation amount changes, It is set by an arithmetic expression. The line q1 shown in FIG. 6 is a change characteristic when the state of charge SOC of the battery 4 is in a high region, and the line q2 is a change characteristic when the state of charge SOC of the battery 4 is in a medium region. q3 is a change characteristic when the state of charge SOC of the battery 4 is in a low region. If the accelerator operation amount is zero, the motor torque output rate A is substantially zero. However, as the accelerator operation amount increases, the motor torque output rate A is set to a larger value. Then, one of the three lines q1, q2, and q3 is applied depending on the state of charge of the battery at that time.

  That is, the line corresponding to any of the three lines q1, q2, and q3 is specified based on the information on the state of charge SOC of the battery 4 detected by the state of charge detection unit S6. Then, the motor torque output rate A is obtained from the information on the accelerator operation amount detected by the line and the accelerator operation amount detection sensor S1.

  Next, the maximum torque Tm that is the maximum value of the power running torque of the electric motor 2 corresponding to the rotational speed of the electric motor 2 at that time is obtained (step 5). This maximum torque Tm corresponds to the value of the power running torque when the motor torque output rate A is the maximum value (100%). As shown in FIG. 7, the change characteristic of the maximum torque with respect to the rotation speed of the electric motor 2 is set in advance by map data. From this change characteristic and information on the rotation speed detected by the rotation speed sensor S3, The maximum torque Tm corresponding to the rotational speed of the electric motor 2 at that time is obtained.

  Next, a motor torque variation coefficient B is obtained based on the vehicle speed information (step 6). As shown in FIG. 8, the change characteristic of the motor torque fluctuation coefficient B with respect to the change in the vehicle speed is set in advance by map data. From this change characteristic and the vehicle speed information detected by the vehicle speed sensor S4, The motor torque fluctuation coefficient B corresponding to the vehicle speed is obtained. As is apparent from FIG. 8, the motor torque variation coefficient B is set in a state where the vehicle speed is higher when the vehicle speed is lower than the set vehicle speed V1 compared to when the vehicle speed is higher than the set vehicle speed V1. It will be. Incidentally, it is set so that the same coefficient value (1.0) is maintained when the vehicle speed is higher than the set vehicle speed V1.

  Then, by multiplying the motor torque output rate A, the maximum torque Tm, and the motor torque fluctuation coefficient B obtained as described above, the target value Ts of the power running torque is obtained (Ts = Tm × A × B), and the electric motor The output process for the electric motor 2 is executed so that 2 outputs the target value Ts of the calculated power running torque (steps 7 and 8). That is, control information corresponding to the target value Tsj of the power running torque is given to the PWM control circuit 29, and a pulse signal is applied from the PWM control circuit 29 to the base terminal of each switching transistor of the inverter 28, so that the electric motor 2 operates in the power running mode. Will do. When the vehicle speed is higher than the set vehicle speed V1, the motor torque variation coefficient B is 1.0, so the target value Ts for powering torque is a value obtained by multiplying the motor torque output rate A and the maximum torque Tm. Is the same. That is, the maximum torque Tm is set as a value when the torque output rate A is maximum (100%) and the torque variation coefficient B is in the high speed state.

  The various map data set for obtaining the power running torque of the electric motor 2 as described above is the rotational speed (electrical) of the engine 1 so that the engine 1 can maintain a high combustion efficiency. In accordance with the rotational speed of the motor 2), it is set in advance based on actually measured data or the like so as to output an appropriate power running torque.

  If it is determined in step 2 that the power running operation condition is not satisfied, the output of the power running torque is stopped, the target value of the regenerative torque is obtained by calculation, and the regenerative torque Output processing for the electric motor 2 is executed so as to output the target value (steps 9, 10, and 11). Although the method for obtaining the target value of the regenerative torque is not described in detail here, it is suitable for the situation of the vehicle at that time based on the information on the state of charge of the battery 4, the vehicle speed, and the amount of accelerator operation. The operation of the electric motor 2 is controlled so that regenerative torque can be obtained.

[Another embodiment]
Hereinafter, other embodiments are listed.

(1) In the above embodiment, as a configuration for setting the target torque for performing the power running operation, the change characteristic of the motor torque variation coefficient B with respect to the change in the vehicle speed is set in advance by map data. From the above information, when the vehicle speed is a low speed state lower than the set vehicle speed, the motor torque fluctuation coefficient is obtained in a state where the vehicle speed is higher than when the vehicle speed is higher than the set vehicle speed. The target torque is determined based on the motor torque output rate and the information on the maximum torque set in advance corresponding to the rotation speed of the electric motor. Instead of such a configuration, the following is used. You may comprise.

  For example, the motor torque output rate is not obtained from one type of map data as in the above embodiment, but the high-speed map data corresponding to the vehicle speed being higher than the set vehicle speed and the vehicle speed is the set vehicle speed. Prepare two different types of map data, low-speed map data that is corrected to a higher torque than high-speed map data in response to the vehicle's lower speed, and respond to vehicle speed detection information. The target torque may be obtained using map data corresponding to any of them.

Further, the map data for the maximum torque is not provided with two types of map data for the motor torque output rate, but the map data for the maximum torque is for high speed when the vehicle speed is higher than the set vehicle speed, and the vehicle speed is higher than the set vehicle speed. Two different types of map data are prepared, one for low speed in a state corrected to a higher torque side than that for high speed in correspondence with the low state, and depending on the detection information of the vehicle speed, The target torque may be obtained using any corresponding map data.
Further, instead of the map data as described above, each change characteristic may be set by an arithmetic expression.

(2) In the above embodiment, the configuration in which the shaft is directly connected so that the engine and the electric motor rotate integrally is exemplified. However, the configuration is not limited to such a configuration in which the shaft is directly connected. It is good also as a structure linked and interlocked in the state rotated integrally via a transmission gear.

Diagram showing schematic configuration of hybrid vehicle Control block diagram The figure which shows the control composition of the electric motor Flow chart showing control operation Explanatory diagram for discriminating power running operating conditions The figure which shows the relationship between the amount of accelerator operation and the motor torque output rate Diagram showing the relationship between rotational speed and maximum torque Diagram showing the relationship between vehicle speed and motor torque variation coefficient

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 2 Electric motor 3 Traveling apparatus 4 Battery H Control means

Claims (3)

The electric motor includes an engine and an electric motor that rotates integrally with the engine as a power source, and is configured to drive the travel device. The electric motor controls the driving state of the vehicle so as to execute a power running operation and a regenerative operation. A hybrid vehicle configured to control the operation of the vehicle,
The control means is
The target torque for performing the power running operation increases as the accelerator operation amount increases, increases as the battery is charged, and increases when the vehicle speed is low and when the vehicle speed is low. A hybrid vehicle that is configured to set to. As a process for obtaining a target torque when the control means performs the power running operation,
Torque output rate obtained when the accelerator operation amount is larger and larger when the battery is charged, and torque fluctuation obtained when the vehicle speed is lower than when it is in a high speed state. The target torque based on information on the coefficient and the maximum torque set according to the rotational speed of the electric motor as a value when the torque output rate is maximum and the torque fluctuation coefficient is in the high speed state. The hybrid vehicle according to claim 1, wherein the hybrid vehicle is configured to obtain The control means includes
The accelerator operation amount is configured to execute the power running operation when a start determination threshold value which is set in advance according to the rotation speed of the engine is exceeded.
The power running operation is stopped when the accelerator operation amount falls below a stop determination threshold value set lower than the start determination threshold value when the engine rotation speed is the same according to the engine rotation speed. The hybrid vehicle according to claim 1 or 2, wherein

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