JP2009143306A - Internal combustion engine device and control method thereof, and power output device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To restrain reverse rotation of an internal combustion engine when the rotation of the internal combustion engine is stopped. <P>SOLUTION: An internal combustion engine device calculates a zero reaching prediction time tz as a predicted time in which the engine speed Ne reaches zero using average engine speed difference ΔNeav based on the engine speed Ne (S140-S160), outputs a torque for reducing rotation from a motor MG1 when the calculated zero reaching prediction time tz is larger than a predetermined time tzref (S180, S130), and outputs a torque for stopping from the motor MG1 after the zero reaching prediction time tz gets to the predetermined time tzref (S180, S200) or lower. Thereby, the engine speed Ne can be smoothly reduced, and the reverse rotation of the engine can be restrained irrespective of the magnitude of the change rate of the engine speed Ne. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an internal combustion engine device, a control method therefor, and a power output device.

Conventionally, as this type of drive device, an engine, a planetary gear mechanism in which a carrier is connected to a crankshaft of the engine and a ring gear is connected to a drive shaft, and a first motor connected to a sun gear of the planetary gear mechanism A device including (MG1) and a second motor (MG2) connected to the drive shaft has been proposed (see, for example, Patent Document 1). In this device, when the engine is stopped, a torque for suppressing the rotation of the engine is output from the motor MG1 until the rotational speed of the engine reaches the rotational speed immediately before stopping, and after the rotational speed of the engine reaches the rotational speed immediately before stopping. Outputs a torque for stopping the engine at the target stop position (torque for holding the piston of the engine, hereinafter referred to as stop torque) from the motor MG1, thereby adjusting the crank angle when the engine stops.
Japanese Patent Laying-Open No. 2005-184999 (FIG. 9)

  In such an internal combustion engine device, when the engine speed decreases more rapidly than expected when a large braking torque acts on the drive shaft while the engine is stopped and the rotational speed of the drive shaft suddenly decelerates, etc. There is. In this case, if the stop torque is output from the motor MG1 after the engine speed reaches the engine speed just before the stop, the engine may reversely rotate depending on the rate of change of the engine speed.

  The internal combustion engine device, the control method thereof, and the power output device of the present invention are mainly intended to suppress reverse rotation of the internal combustion engine when the internal combustion engine is stopped.

  The drive device, the control method thereof, and the vehicle according to the present invention employ the following means in order to achieve the main object described above.

The internal combustion engine device of the present invention is
An internal combustion engine device comprising an internal combustion engine and an electric motor capable of outputting torque to an output shaft of the internal combustion engine,
Engine speed detecting means for detecting an engine speed which is the speed of the internal combustion engine;
When the fuel supply to the internal combustion engine is stopped to stop the rotation of the internal combustion engine, a predicted zero arrival time, which is a time when the engine speed is predicted to reach zero based on the detected engine speed, The rotation reduction control is performed to control the electric motor so that a rotation reduction torque as a torque for reducing the engine speed is output from the electric motor before the estimated zero arrival predicted time reaches a predetermined time or less. Then, after the estimated zero arrival predicted time has reached the predetermined time or less, stop control for controlling the electric motor so that a stopping torque as a torque for stopping the internal combustion engine at a target stop position is output from the electric motor. A stop time control means for executing
It is a summary to provide.

  In the internal combustion engine device of the present invention, when stopping the rotation of the internal combustion engine by stopping the fuel supply to the internal combustion engine, the engine rotational speed reaches zero based on the engine rotational speed that is the rotational speed of the internal combustion engine. Estimate the predicted zero arrival time, which is the predicted time, and before the estimated zero arrival predicted time reaches a predetermined time or less, rotate the motor so that torque for reducing rotation as torque for reducing the engine speed is output from the motor. The rotation reduction control to be controlled is executed. Thereby, engine speed can be reduced smoothly. Then, after the estimated zero arrival predicted time reaches a predetermined time or less, stop control for controlling the electric motor is executed so that a stopping torque as a torque for stopping the internal combustion engine at the target stop position is output from the electric motor. Thus, if the predetermined time is set appropriately, it is possible to suppress the internal combustion engine from rotating backward regardless of the degree of change in the engine speed when the internal combustion engine is stopped.

  In such an internal combustion engine apparatus of the present invention, when the engine speed detected is less than or equal to a predetermined number of revolutions, the control unit at the time of stop is when the detected engine speed is less than or equal to the predetermined number of revolutions even before the estimated zero arrival predicted time reaches the predetermined time or less It may be a means for executing the stop control. If it carries out like this, when stopping an internal combustion engine, it can suppress more reliably that an internal combustion engine reversely rotates.

  Further, in the internal combustion engine device of the present invention, when the detected engine speed is equal to or higher than a second predetermined speed, the stop time control means performs the rotation reduction control regardless of the estimated zero arrival predicted time. It can also be a means of performing. The stop-time control means is means for executing the rotation reduction control or the stop control based on the estimated zero arrival predicted time after executing the rotation reduction control over a second predetermined time. It can also be.

  Further, in the internal combustion engine apparatus of the present invention, the stop time control means calculates an engine speed change rate, which is a change amount of the engine speed per unit time, based on the detected engine speed, and the calculation. It can also be a means for estimating the estimated zero arrival time based on the engine speed change rate.

The power output apparatus of the present invention is
A power output device that outputs power to a drive shaft,
The internal combustion engine apparatus of the present invention according to any one of the above-described aspects, that is, an internal combustion engine apparatus basically including an internal combustion engine and an electric motor capable of outputting torque to an output shaft of the internal combustion engine, An engine speed detecting means for detecting an engine speed that is the engine speed, and when stopping the rotation of the internal combustion engine by stopping the fuel supply to the internal combustion engine, the engine speed is detected based on the detected engine speed. Estimating a zero arrival prediction time, which is a time when the engine speed is predicted to reach zero, and a torque for reducing the rotation as a torque for reducing the engine speed before the estimated zero arrival prediction time reaches a predetermined time or less Rotation reduction control for controlling the electric motor so that is output from the electric motor, and after the estimated zero arrival predicted time reaches the predetermined time or less, the torque that stops the internal combustion engine at the target stop position An internal combustion engine system stop torque and is and a stop control means for performing stop control for controlling the electric motor so as to be output from the electric motor,
Connected to the three shafts of the output shaft of the internal combustion engine, the drive shaft, and the rotating shaft of the electric motor, power is applied to the remaining shaft based on the power input / output to / from any two of the three shafts. 3-axis power input / output means for outputting;
Unlike the electric motor, a second electric motor capable of outputting torque to the drive shaft;
Power storage means capable of exchanging electric power with the electric motor and the second electric motor;
The internal combustion engine, the electric motor, and the second electric motor so that when the operation of the internal combustion engine is stopped, the internal combustion engine functions as the stop-time control means, and torque based on the required torque to be output to the drive shaft is output to the drive shaft. Control means for controlling
It is a summary to provide.

  Since the power output apparatus of the present invention includes the internal combustion engine apparatus of the present invention according to any one of the above-described aspects, for example, the effect of the internal combustion engine apparatus of the present invention, for example, the rotation speed of the internal combustion engine can be reduced. Regardless of the rate of change, it is possible to achieve the same effect as the effect of suppressing the reverse rotation of the internal combustion engine.

The control method of the internal combustion engine device of the present invention includes:
A control method for an internal combustion engine device comprising an internal combustion engine and an electric motor capable of outputting torque to an output shaft of the internal combustion engine,
When the fuel supply to the internal combustion engine is stopped to stop the rotation of the internal combustion engine, zero is the time that the engine speed is expected to reach zero based on the engine speed that is the speed of the internal combustion engine Rotation for estimating the arrival prediction time and controlling the electric motor so that a rotation reduction torque as a torque for reducing the engine speed is output from the electric motor before the estimated zero arrival prediction time reaches a predetermined time or less. After the reduction control is executed and the estimated zero arrival predicted time reaches the predetermined time or less, the motor is controlled so that a stopping torque as a torque for stopping the internal combustion engine at the target stop position is output from the motor. Execute stop control to control,
It is characterized by that.

  In this control method for an internal combustion engine device according to the present invention, when the fuel supply to the internal combustion engine is stopped to stop the rotation of the internal combustion engine, the engine speed is zero based on the engine speed that is the speed of the internal combustion engine. Estimated zero arrival prediction time, which is the time that is predicted to reach, and before the estimated zero arrival prediction time reaches a predetermined time or less, rotation reduction torque is output from the motor as torque for reducing the engine speed. The rotation reduction control for controlling the electric motor is executed. Thereby, engine speed can be reduced smoothly. Then, after the estimated zero arrival predicted time reaches a predetermined time or less, stop control for controlling the electric motor is executed so that a stopping torque as a torque for stopping the internal combustion engine at the target stop position is output from the electric motor. Thus, if the predetermined time is set appropriately, it is possible to suppress the internal combustion engine from rotating backward regardless of the degree of change in the engine speed when the internal combustion engine is stopped.

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

  FIG. 1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 equipped with a power output apparatus according to an embodiment of the present invention. As shown in the figure, the hybrid vehicle 20 of the embodiment includes an engine 22, a three-shaft power distribution / integration mechanism 30 connected to a crankshaft 26 as an output shaft of the engine 22 via a damper 28, and power distribution / integration. A motor MG1 capable of generating electricity connected to the mechanism 30, a reduction gear 35 attached to a ring gear shaft 32a as a drive shaft connected to the power distribution and integration mechanism 30, a motor MG2 connected to the reduction gear 35, A brake actuator 92 for controlling the brakes of the drive wheels 63a and 63b and a driven wheel (not shown) and a hybrid electronic control unit 70 for controlling the entire power output apparatus are provided.

  The engine 22 is configured as a four-cylinder internal combustion engine that can output power by using a hydrocarbon fuel such as gasoline or light oil, for example, and an engine electronic control unit (hereinafter referred to as an engine ECU) 24 performs fuel injection control or Operation control such as ignition control and intake air amount adjustment control is applied. The engine ECU 24 receives signals from various sensors that detect the operating state of the engine 22, for example, a crank position from a crank position sensor 23a that detects the crank angle of the crankshaft 26 of the engine 22. The engine ECU 24 is in communication with the hybrid electronic control unit 70, controls the operation of the engine 22 by a control signal from the hybrid electronic control unit 70, and, if necessary, transmits data related to the operating state of the engine 22 to the hybrid electronic control. Output to unit 70. The engine ECU 24 also calculates the rotational speed of the crankshaft 26, that is, the rotational speed Ne of the engine 22, based on the crank position from the crank position sensor 23a.

  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 rotational elements. In the power distribution and integration mechanism 30, the crankshaft 26 of the engine 22 is connected to the carrier 34, the motor MG1 is connected to the sun gear 31, and the reduction gear 35 is connected to the ring gear 32 via the ring gear shaft 32a. When functioning as a generator, power from the engine 22 input from the carrier 34 is distributed according to the gear ratio between the sun gear 31 side and the ring gear 32 side, and when the motor MG1 functions as an electric motor, the engine input from the carrier 34 The power from 22 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 drive wheels 63a and 63b of the vehicle via the gear mechanism 60 and the differential gear 62.

  The motor MG1 and the motor MG2 are both configured as well-known synchronous generator motors that can be driven as generators and can be driven as motors, and exchange power with the battery 50 via inverters 41 and 42. The power line 54 connecting the inverters 41 and 42 and the battery 50 is configured as a positive electrode bus and a negative electrode bus shared by the inverters 41 and 42, and the electric power generated by one of the motors MG1 and MG2 It can be consumed by a motor. Therefore, battery 50 is charged / discharged by electric power generated from one of motors MG1 and MG2 or insufficient electric power. If the balance of electric power is balanced by the motors MG1 and MG2, the battery 50 is not charged / discharged. The motors MG1 and MG2 are both driven and controlled by a motor electronic control unit (hereinafter referred to as a motor ECU) 40. The motor ECU 40 detects 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 phase current applied to the motors MG1 and MG2 to be applied is input, and a switching control signal to the inverters 41 and 42 is output from the motor ECU 40. The motor ECU 40 is in communication with the hybrid electronic control unit 70, controls the driving of the motors MG1 and MG2 by a control signal from the hybrid electronic control unit 70, and, if necessary, data on the operating state of the motors MG1 and MG2. Output to the hybrid electronic control unit 70. The motor ECU 40 also calculates the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 based on signals from the rotational position detection sensors 43 and 44.

  The battery 50 is managed by a battery electronic control unit (hereinafter referred to as a battery ECU) 52. The battery ECU 52 receives signals necessary for managing the battery 50, for example, a voltage between terminals from a voltage sensor (not shown) installed between terminals of the battery 50, and a power line 54 connected to the output terminal of the battery 50. The charging / discharging current from the attached current sensor (not shown), the battery temperature Tb from the temperature sensor 51 attached to the battery 50, and the like are input. Output to the control unit 70. Further, the battery ECU 52 calculates the remaining capacity (SOC) based on the integrated value of the charging / discharging current detected by the current sensor in order to manage the battery 50, and calculates the remaining capacity (SOC) and the battery temperature Tb. The input / output limits Win and Wout, which are the maximum allowable power that may charge / discharge the battery 50, are calculated based on the above. The input / output limits Win and Wout of the battery 50 are set to the basic values of the input / output limits Win and Wout based on the battery temperature Tb, and the output limiting correction coefficient and the input are set based on the remaining capacity (SOC) of the battery 50. It can be set by setting a correction coefficient for restriction and multiplying the basic value of the set input / output restrictions Win and Wout by the correction coefficient.

  The brake actuator 92 has a braking torque according to the share of the brake in the braking force applied to the vehicle by the pressure (brake pressure) of the brake master cylinder 90 and the vehicle speed V generated in response to the depression of the brake pedal 85. The brake wheel cylinders 96a and 96d are adjusted so as to act on the driven wheel 63b and a driven wheel (not shown), and the braking torque is applied to the drive wheels 63a and 63b and the driven wheel regardless of the depression of the brake pedal 85. The hydraulic pressures of 96a to 96d can be adjusted. The brake actuator 92 is controlled by a brake electronic control unit (hereinafter referred to as a brake ECU) 94. The brake ECU 94 inputs signals such as a wheel speed from a wheel speed sensor (not shown) attached to the driving wheels 63a and 63b and the driven wheel and a steering angle from a steering angle sensor (not shown) by a signal line (not shown). When the driver depresses the brake pedal 85, an anti-lock brake system function (ABS) that prevents any of the driving wheels 63a, 63b and the driven wheels from slipping due to the lock or when the driver depresses the accelerator pedal 83 Traction control (TRC) for preventing any one of the drive wheels 63a and 63b from slipping due to idling, posture holding control (VSC) for holding the posture while the vehicle is turning, and the like are also performed. The brake ECU 94 communicates with the hybrid electronic control unit 70, and controls the drive of the brake actuator 92 by a control signal from the hybrid electronic control unit 70, and the data regarding the state of the brake actuator 92 is used for the hybrid as necessary. Output to the electronic control unit 70.

  The hybrid electronic control unit 70 is configured as a microprocessor centered on the CPU 72, and in addition to the CPU 72, a ROM 74 for storing processing programs, a RAM 76 for temporarily storing data, an input / output port and communication not shown. And a port. The hybrid electronic control unit 70 includes an ignition signal from an ignition switch 80, a shift position SP from a shift position sensor 82 that detects the operation position of the shift lever 81, and an accelerator pedal position sensor 84 that detects the amount of depression of the accelerator pedal 83. The accelerator pedal opening Acc from the vehicle, the brake pedal position BP from the brake pedal position sensor 86 for detecting the depression amount of the brake pedal 85, the vehicle speed V from the vehicle speed sensor 88, and the like are input via the input port. Further, the crank position from the crank position sensor 23a is directly inputted to the hybrid electronic control unit 70 via the engine ECU 24. As described above, the hybrid electronic control unit 70 is connected to the engine ECU 24, the motor ECU 40, the battery ECU 52, and the brake ECU 94 via a communication port, and the engine ECU 24, the motor ECU 40, the battery ECU 52, the brake ECU 94, and various control signals. And exchanging data.

  The hybrid vehicle 20 of the embodiment thus configured calculates the required torque to be output to the ring gear shaft 32a as the drive shaft based on the accelerator opening Acc and the vehicle speed V corresponding to the depression amount of the accelerator pedal 83 by the driver. Then, the operation of the engine 22, the motor MG1, and the motor MG2 is controlled so that the required power corresponding to the required torque is output to the ring gear shaft 32a. As operation control of the engine 22, the motor MG1, and the motor MG2, the operation of the engine 22 is controlled so that the power corresponding to the required power is output from the engine 22, and all of the power output from the engine 22 is the power distribution and integration mechanism 30. Torque conversion operation mode for driving and controlling the motor MG1 and the motor MG2 so that the torque is converted by the motor MG1 and the motor MG2 and output to the ring gear shaft 32a, and the required power and the power required for charging and discharging the battery 50. The engine 22 is operated and controlled so that suitable 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 the power distribution integration mechanism 30, the motor MG1, and the motor. The required power is converted to the ring gear shaft 32 with torque conversion by MG2. Charge / discharge operation mode in which the motor MG1 and the motor MG2 are driven and controlled so as to be output to each other, and a motor operation mode in which the operation of the engine 22 is stopped and the power corresponding to the required power from the motor MG2 is output to the ring gear shaft 32a. and so on.

  Next, the operation of the hybrid vehicle 20 of the embodiment configured as described above, particularly the operation when the engine 22 is stopped will be described. In the process of stopping the engine 22, for example, the vehicle required power required for the vehicle from the state of the accelerator opening Acc, the vehicle speed V, and the battery 50 in a state where the vehicle speed V is less than a threshold at which the engine 22 may be stopped is less than the threshold. This is performed when there is no other request to continue the operation of the engine 22. FIG. 2 is a flowchart showing an example of an engine stop time control routine executed by the hybrid electronic control unit 70. This routine is repeatedly executed at predetermined time intervals (for example, every several msec) when the operation stop of the engine 22 is instructed. The engine ECU 24 stops fuel injection in the engine 22 at the same time as the processing by the engine stop time control routine is started.

  When the engine stop time control routine is executed, first, the CPU 72 of the hybrid electronic control unit 70 first determines the accelerator opening Acc from the accelerator pedal position sensor 84, the brake pedal position BP from the brake pedal position sensor 86, and the vehicle speed sensor 88. Data input for inputting data necessary for control, such as the vehicle speed V from the engine, the rotational speed Ne of the engine 22, the rotational speeds Nm1 and Nm of the motors MG1 and MG2, the crank angle CA from the crank position sensor 23a, and the input limit Win of the battery 50 Processing is executed (step S100). Here, the rotation speed Ne of the engine 22 is input from the crank position detected by the crank position sensor 23a, and the rotation speeds Nm1 and Nm2 of the motors MG1 and MG2 are the rotation position detection sensor 43, What is calculated based on the rotational position of the rotor of the motors MG1 and MG2 detected by the motor 44 is input from the motor ECU 40 by communication. In addition, the crank angle CA is determined by using the crank position detected by the crank position sensor 23a as an angle from the reference angle, and the input limit Win of the battery 50 is the battery of the battery 50 detected by the temperature sensor 51. What is set based on the temperature Tb and the remaining capacity (SOC) of the battery 50 is input from the battery ECU 52 by communication. The input limit Win is set as a negative value so that the larger the amount of power that can be input to the battery 50, the smaller the input limit Win.

  When the data is input in this way, the required torque Tr * to be output to the ring gear shaft 32a as the drive shaft is set based on the accelerator opening Acc, the brake pedal position BP, and the vehicle speed V (step S110). In the embodiment, the required torque Tr * is obtained in advance by storing the relationship between the accelerator opening Acc, the brake pedal position BP, the vehicle speed V and the required torque Tr * in the ROM 74 as a required torque setting map. When Acc, brake pedal position BP, and vehicle speed V are given, the corresponding required torque Tr * is derived from the required torque setting map. FIG. 3 shows an example of the required torque setting map.

  Subsequently, the rotational speed Ne of the engine 22 is compared with a threshold value Nref1 (step S120). Here, for example, 500 rpm or 600 rpm can be used as the threshold value Nref1. The reason for using this threshold value Nref1 will be described later. When the rotational speed Ne of the engine 22 is equal to or greater than the threshold value Nref1, the rotational speed Ne is smoothly reduced (reduced) based on the crank angle CA and the torque is reduced as a torque that suppresses vibration associated with the rotation of the engine 22. The torque is set to the torque command Tm1 * of the motor MG1 and transmitted to the motor ECU 40 (step S130). The motor ECU 40 that has received the torque command Tm1 * performs switching control of the switching element of the inverter 41 so that the motor MG1 is driven by the torque command Tm1 *. FIG. 4 shows an example of a collinear diagram for dynamically explaining the rotational elements of the power distribution and integration mechanism 30 when the rotational speed Ne of the engine 22 is reduced while the fuel supply to the engine 22 is stopped. . In the figure, the left S-axis indicates the rotation speed of the sun gear 31 that is the rotation speed Nm1 of the motor MG1, the C-axis indicates the rotation speed of the carrier 34 that is the rotation speed Ne of the engine 22, and the R-axis indicates the rotation speed of the motor MG2. The rotational speed Nr of the ring gear 32 obtained by dividing the number Nm2 by the gear ratio Gr of the reduction gear 35 is shown. The arrow on the S axis indicates the torque for reducing rotation output from the motor MG1 to the sun gear 31, and the arrow on the C axis indicates the torque acting on the carrier 34 due to sliding friction or compression work caused by the rotation of the engine 22. The arrow on the R axis indicates the torque output from the motor MG2 to the ring gear shaft 32a via the reduction gear 35.

  When the torque command Tm1 * of the motor MG1 is set in this way, a temporary motor torque Tm2tmp as a torque to be output from the motor MG2 using the required torque Tr *, the torque command Tm1 *, and the gear ratio ρ of the power distribution and integration mechanism 30 is expressed by the following equation: Calculated by (1) (step S210), and the power consumption (generated power) of the motor MG1 obtained by multiplying the input limit Win of the battery 50 and the torque command Tm1 * of the motor MG1 by the current rotational speed Nm1 of the motor MG1 Is divided by the rotational speed Nm2 of the motor MG2 to calculate a torque limit Tmin as a lower limit of the torque that may be output from the motor MG2 by the equation (2) (step S220), and the motor temporary torque Tm2tmp is calculated as the torque limit Tmin. Set the torque command Tm2 * of the motor MG2 as the value limited by To send to the over data ECU40 (step S230). The motor ECU 40 that has received the torque command Tm2 * performs switching control of the switching element of the inverter 42 so that the torque of the torque command Tm2 * from the motor MG2 is output. Thus, by setting the torque command Tm2 * of the motor MG2, the required torque Tr * output to the ring gear shaft 32a as the drive shaft can be set as a torque limited within the range of the input limit Win of the battery 50. it can. Equation (1) can be easily derived from the collinear diagram of FIG. 4 described above.

Tm2tmp = (Tr * + Tm1 * / ρ) / Gr (1)
Tmin = (Win-Tm1 * ・ Nm1) / Nm2 (2)

  Next, assuming that the torque command Tm2 * of the motor MG2 multiplied by the gear ratio Gr of the reduction gear 35 is subtracted from the required torque Tr *, the drive wheel 63a is driven via the brake wheel cylinders 96a to 96d by the operation of the brake actuator 92. , 63b and a braking torque command Tb * as a braking force to be applied to the driven wheel are set and transmitted to the brake ECU 94 (step S240), and the engine stop time control routine is terminated. The brake ECU 94 that has received the brake torque command Tb * operates the brake actuator 92 so that the braking torque converted to the ring gear shaft 32a becomes the brake torque command Tb * to apply the braking force to the drive wheels 63a, 63b and the driven wheels. .

  When the rotational speed Ne of the engine 22 is less than the threshold value Nref1 in step S120, the rotational speed Ne of the engine 22 input when the routine was executed last time (previous Ne) is subtracted from the rotational speed Ne of the engine 22 input this time. Thus, the rotation speed difference ΔNe is calculated (step S140), and the sum of the rotation speed difference ΔNe calculated this time and the rotation speed difference calculated last time (previous ΔNe) is divided by the value 2, thereby averaging the rotation speed difference ΔNe. Is calculated (step S150), and the rotational speed Ne of the engine 22 is divided from the current value to zero by dividing the rotational speed Ne of the engine 22 by the absolute value of the calculated average rotational speed difference ΔNeav. The zero arrival prediction time tz is calculated as a time predicted to be required until (step S160). Here, the absolute value of the average rotational speed difference ΔNeav is used because the average rotational speed difference ΔNeav becomes a negative value when the rotational speed Ne of the engine 22 is decreasing.

  Subsequently, it is determined whether or not the engine 22 has completely stopped (step S170). Here, the determination as to whether or not the engine 22 has completely stopped can be made, for example, by examining whether or not a predetermined time has elapsed with the rotational speed Ne of the engine 22 being zero. When it is determined that the engine 22 is not completely stopped, the zero arrival prediction time tz is compared with the threshold value tzref (step S180), and the rotation speed Ne of the engine 22 is compared with the threshold value Nref2 (step S190). When the predicted arrival time tz is greater than the threshold value tzref and the rotational speed Ne of the engine 22 is greater than the threshold value Nref2, the rotation reduction torque is set to the torque command Tm1 * of the motor MG1 and transmitted to the motor ECU 40 (step S130). The torque command Tm2 * of the motor MG2 is set using Tm1 * and transmitted to the motor ECU 40 (steps S210 to S230), the brake torque command Tb * is set and transmitted to the brake ECU 94 (step S240), and the engine is stopped. End the hour control routine. Here, the threshold value tzref and the threshold value Nref2 are used to determine whether or not the engine 22 may rotate in the reverse direction when the output of the rotation reduction torque from the motor MG1 is continued. For example, 50 ms or 60 ms can be used, and for the threshold Nref2, for example, 300 rpm or 350 rpm can be used. As described above, when the predicted zero arrival time tz is larger than the threshold value tzref and the rotational speed Ne of the engine 22 is larger than the threshold value Nref2, the engine 22 can be smoothly lowered by outputting the rotation reduction torque from the motor MG1. .

  On the other hand, when the zero arrival prediction time tz is less than or equal to the threshold tzref, or when the zero arrival prediction time tz is greater than the threshold tzref but the engine speed Ne is less than or equal to the threshold Nref2, the engine 22 may rotate in the reverse direction. Based on the crank angle CA, it is determined that there is a stop torque as a torque for stopping the engine 22 at a target stop position (for example, near the top dead center of the compression stroke) without rotating the engine 22 backward. * Is set and transmitted to the motor ECU 40 (step S200), the torque command Tm2 * of the motor MG2 is set using the torque command Tm1 * and is transmitted to the motor ECU 40 (steps S210 to S230), and the brake torque command Tb * is transmitted. Is transmitted to the brake ECU 94 (step S240), and the engine is stopped. To end the routine. Here, as the stopping torque, torque that gently stops the engine 22 at the target stop position based on the crank angle CA is used, and in the embodiment, positive torque is used. Considering that the brake pedal 85 is greatly depressed while the engine 22 is stopped, the rotational speed Nr (= Nm2 / Gr) of the ring gear shaft 32a is suddenly decelerated and the motor MG1 By outputting torque, the rotational speed Ne of the engine 22 decreases relatively quickly. In this case, when the torque output from the motor MG1 is switched from the rotation reduction torque to the stop torque using only the rotation speed Ne of the engine 22, the engine 22 rotates in the reverse direction due to the rapid decrease in the rotation speed Ne of the engine 22. May end up. On the other hand, in the embodiment, since the torque output from the motor MG1 is switched from the rotation reduction torque to the stop torque using the zero arrival prediction time tz in addition to the rotation speed Ne of the engine 22, the rotation speed of the engine 22 is changed. Even when Ne decreases relatively quickly, the reverse rotation of the engine 22 can be suppressed. As described above, when the rotational speed Ne of the engine 22 is equal to or greater than the threshold value Nref1, the rotation reduction torque is set to the torque command Tm1 * of the motor MG1 without calculating the zero arrival prediction time tz ( S120, S130), when the rotational speed Ne of the engine 22 is large to some extent, the average rotational speed difference ΔNeav is temporarily increased, and when the zero arrival predicted time tz becomes less than or equal to the threshold value tzref, the motor MG1 outputs This is to prevent the torque from switching from the rotation reduction torque to the stop torque.

  When it is determined in step S170 that the engine 22 has completely stopped while repeatedly executing this routine, the engine stop time control routine is terminated. Thereafter, a drive control routine during motor travel (not shown) in a motor operation mode in which the vehicle travels only with output torque from the motor MG2 is repeatedly executed.

  FIG. 5 is an explanatory diagram showing changes in time of the engine speed Ne, the zero arrival predicted time tz, and the output torque Tm1 of the motor MG1 when the fuel injection of the engine 22 is stopped and the engine 22 is stopped. It is. In the figure, the solid line indicates the time change of the embodiment, and the alternate long and short dash line indicates that the output torque of the motor MG1 is changed from the rotation reduction torque to the stop torque using only the rotation speed Ne of the engine 22 without using the zero arrival prediction time tz. The time change of the comparative example when changing is shown. After time t0 when the engine 22 is instructed to stop and the fuel cut of the engine 22 is performed, the rotation reduction torque is output from the motor MG1, and the rotation speed Ne of the engine 22 is smoothly reduced. When the brake pedal 85 is greatly depressed at a subsequent time t1 and a large braking force is applied to the ring gear shaft 32a and its rotational speed starts to decelerate rapidly, the rotational speed Ne of the engine 22 begins to rapidly decrease accordingly. . In the comparative example, the engine 22 rotates in reverse in order to switch the output torque of the motor MG1 from the rotation reduction torque to the stop torque at time t3 when the rotational speed Ne of the engine 22 reaches less than the threshold value Nref2. In order to switch the output torque of the motor MG1 from the rotation reduction torque to the stop torque regardless of the rotational speed Ne of the engine 22 at the time t2 (time before time t3) when the zero arrival prediction time tz reaches the threshold value tzref or less, It is possible to suppress reverse rotation of the engine 22.

  According to the hybrid vehicle 20 of the embodiment described above, when the fuel injection of the engine 22 is stopped and the engine 22 is stopped, the rotation speed Ne is calculated using the average rotation speed difference ΔNeav based on the rotation speed Ne of the engine 22. Is calculated as a time predicted to take from the current value to zero, and when the calculated zero arrival prediction time tz is greater than the predetermined time tzref, rotation reduction torque is output from the motor MG1. Since the stop torque is output from the motor MG1 after the predicted zero arrival time tz is less than or equal to the predetermined time tzref, the rotational speed Ne of the engine 22 can be reduced smoothly and the rotational speed Ne of the engine 22 changes. Regardless of the rate, the reverse rotation of the engine 22 can be suppressed.

  In the hybrid vehicle 20 of the embodiment, the average rotational speed difference ΔNeav as the average of the past two revolutions of the rotational speed difference ΔNe obtained by subtracting the previous rotational speed Ne (previous Ne) from the current rotational speed Ne of the engine 22 and the current rotational speed. The zero arrival prediction time tz is calculated using Ne, but for example, the zero arrival prediction time tz is calculated using an average rotation speed difference as an average of the past n (n is an integer of 3 or more) times. Any method may be used as long as it calculates the zero arrival prediction time tz, such as calculating the zero arrival prediction time tz using the rotation speed difference ΔNe instead of the average rotation speed difference ΔNeav.

  In the hybrid vehicle 20 of the embodiment, when the rotational speed Ne of the engine 22 is equal to or greater than the threshold value Nref1, the rotation reduction torque is output from the motor MG1 regardless of the zero arrival prediction time tz. 2 until the predetermined time (200 msec, 250 msec, 300 msec, etc.) elapses after the execution of the engine stop control routine of No. 2 is started (after the operation stop of the engine 22 is instructed) or from the motor MG1. Until a predetermined time (200 msec, 250 msec, 300 msec, etc.) has elapsed since the start of the output of, the rotation reduction torque may be output from the motor MG1 regardless of the zero arrival predicted time tz.

  In the hybrid vehicle 20 of the embodiment, when the rotational speed Ne of the engine 22 is greater than or equal to the threshold value Nref1, the rotation reduction torque is output from the motor MG1 regardless of the zero arrival prediction time tz, and the rotational speed Ne of the engine 22 is less than the threshold value Nref1. Sometimes, the motor MG1 outputs the torque for reducing rotation or the torque for stopping based on the predicted zero arrival time tz, but the rotation based on the predicted zero arrival time tz regardless of whether the rotational speed Ne is less than the threshold value Nref1. The lowering torque or the stopping torque may be output from the motor MG1.

  In the hybrid vehicle 20 of the embodiment, when the rotation speed Ne of the engine 22 is less than the threshold value Nref1, the comparison result between the zero arrival predicted time tz and the threshold value tzref and the comparison result between the rotation speed Ne and the threshold value Nref2 are used. The rotation reduction torque or the stop torque is output from the motor MG1, but the rotation decrease torque or the stop torque is output from the motor MG1 using only the comparison result between the zero arrival predicted time tz and the threshold value tzref. It is good.

  In the hybrid vehicle 20 of the embodiment, in the engine stop time control routine of FIG. 2, the rotational speed Ne of the engine 22 calculated from the crank position detected by the crank position sensor 23a and input from the engine ECU 24 by communication is used. However, instead of this, the rotational speed Ne of the engine 22 calculated by the following equation (3) using the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 may be used. Equation (3) can be easily derived using the alignment chart of FIG.

  Ne = (ρ ・ Nm1 + Nm2 / Gr) / (1 + ρ) (3)

  In the hybrid vehicle 20 of the embodiment, the power of the motor MG2 is shifted by the reduction gear 35 and output to the ring gear shaft 32a. However, as illustrated in the hybrid vehicle 120 of the modified example of FIG. May be output to an axle (an axle connected to the wheels 64a and 64b in FIG. 6) different from an axle to which the ring gear shaft 32a is connected (an axle to which the drive wheels 63a and 63b are connected).

  In the hybrid vehicle 20 of the embodiment, the power of the engine 22 is output to the ring gear shaft 32a as the drive shaft connected to the drive wheels 63a and 63b via the power distribution and integration mechanism 30, but the modified example of FIG. The hybrid vehicle 220 includes an inner rotor 232 connected to the crankshaft 26 of the engine 22 and an outer rotor 234 connected to a drive shaft that outputs power to the drive wheels 63a and 63b. A counter-rotor motor 230 that transmits a part of the power to the drive shaft and converts the remaining power into electric power may be provided.

  Further, if the internal combustion engine and an electric motor capable of outputting torque to the output shaft of the internal combustion engine are provided, the same control as the engine stop driving control routine of the above-described embodiment can be performed. And a power output device or an internal combustion engine device mounted on a moving body such as an automobile, a vehicle, a ship, or an aircraft equipped with an electric motor capable of outputting torque to the output shaft of the internal combustion engine. It is good also as a form of the power output device incorporated in the thing which does not move, or an internal combustion engine apparatus. Moreover, it is good also as a form of the control method of such an internal combustion engine apparatus or a power output device.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the embodiment, the engine 22 corresponds to the “internal combustion engine”, the motor MG1 corresponds to the “electric motor”, and the rotation of the engine 22 is performed based on the crank position sensor 23a that detects the crank position and the crank position from the crank position sensor 23a. The engine ECU 24 that calculates the number Ne corresponds to “engine speed detection means”, and when the engine 22 is stopped, the engine speed Ne is currently calculated using the average speed difference ΔNeav based on the engine speed Ne. A zero arrival prediction time tz as a time predicted to take from the value to zero is calculated, and when the calculated zero arrival prediction time tz is greater than a predetermined time tzref, the rotation reduction torque is set as the torque command Tm1 * of the motor MG1. Is transmitted to the motor ECU 40, and the zero arrival predicted time tz is predetermined. After reaching the interval tzref or less, the hybrid electronic control unit 70 for executing the engine stop time control routine of FIG. 2 for setting the stop torque to the torque command Tm1 * of the motor MG1 and transmitting it to the motor ECU 40, and the received torque The motor ECU 40 that controls the motor MG1 based on the command Tm1 * corresponds to the “stop-time control means”. Further, the power distribution and integration mechanism 30 corresponds to “three-axis power input / output means”, the motor MG2 corresponds to “second electric motor”, and the battery 50 corresponds to “power storage means”.

  Here, the “internal combustion engine” is not limited to an internal combustion engine that outputs power using a hydrocarbon fuel such as gasoline or light oil, and may be any type of internal combustion engine such as a hydrogen engine. The “motor” is not limited to the motor MG1 configured as a synchronous generator motor, and may be any type of motor that can output torque to the output shaft of the internal combustion engine, such as an induction motor. I do not care. The “engine speed detection means” is not limited to the crank position sensor 23a for detecting the crank position and the engine ECU 24 for calculating the speed Ne of the engine 22 based on the crank position from the crank position sensor 23a. Any method may be used as long as it detects the engine speed, which is the speed of the internal combustion engine. The “stop-time control means” is not limited to the combination of the hybrid electronic control unit 70 and the motor ECU 40, and may be configured by a single electronic control unit. Further, as the “stop-time control means”, when the rotation of the engine 22 is stopped, it is necessary for the rotation speed Ne to reach zero from the current value by using the average rotation speed difference ΔNeav based on the rotation speed Ne of the engine 22. A predicted zero arrival time tz as a predicted time is calculated. When the calculated zero arrival predicted time tz is larger than the predetermined time tzref, the rotation reduction torque is set to the torque command Tm1 * of the motor MG1 to control the motor MG1. After the zero arrival predicted time tz reaches the predetermined time tzref or less, the torque is not limited to the control of the motor MG1 by setting the stop torque to the torque command Tm1 * of the motor MG1, and the fuel to the internal combustion engine is not limited. When the supply is stopped and the internal combustion engine is stopped, the engine speed is estimated to be zero based on the engine speed. Estimated arrival time is estimated, and rotation reduction control is performed to control the motor so that rotation reduction torque is output from the motor as torque that reduces engine speed before the estimated zero arrival prediction time reaches a predetermined time or less. Then, after the estimated zero arrival predicted time reaches a predetermined time or less, stop control is performed to control the motor so that a stop torque as a torque for stopping the internal combustion engine at the target stop position is output from the motor. It does not matter as long as there is any. The “three-axis power input / output means” is not limited to the power distribution / integration mechanism 30 described above, but includes four or more shafts using a double pinion type planetary gear mechanism or a combination of a plurality of planetary gear mechanisms. Connected to the three shafts such as the one connected to the shaft or the differential gear, or the like having a different operation from the planetary gear, such as the drive shaft, the output shaft, and the rotating shaft of the generator. As long as the power is input / output to / from the remaining shafts based on the power input / output to / from the power source, any method may be used. The “second motor” is not limited to the motor MG2 configured as a synchronous generator motor, and may be any type of motor that can output torque to the drive shaft, such as an induction motor. I do not care. The “storage means” is not limited to the battery 50 as a secondary battery, and may be anything as long as it can exchange power with a power motive power input / output means or an electric motor such as a capacitor. The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the column of means for solving the problem. It is an example for specifically explaining the best mode for doing so, and does not limit the elements of the invention described in the column of means for solving the problem. That is, the interpretation of the invention described in the column of means for solving the problems should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problems. It is only a specific example.

  The best mode for carrying out the present invention has been described with reference to the embodiments. However, the present invention is not limited to these embodiments, and various modifications can be made without departing from the gist of the present invention. Of course, it can be implemented in the form.

  The present invention is applicable to the manufacturing industry of internal combustion engine devices and power output devices.

It is a block diagram which shows the outline of a structure of the hybrid vehicle 20 carrying the power output device which is one Example of this invention. It is a flowchart which shows an example of the control routine at the time of an engine stop performed by the hybrid electronic control unit 70 of an Example. It is explanatory drawing which shows an example of the map for request | requirement torque setting. FIG. 3 is an explanatory diagram showing an example of a collinear diagram for dynamically explaining the rotational elements of the power distribution and integration mechanism 30 when the rotational speed Ne of the engine 22 is reduced while fuel supply to the engine 22 is stopped. is there. It is explanatory drawing which shows the mode of the time change of the rotation speed Ne of the engine 22, the zero arrival prediction time tz, and the output torque Tm1 of the motor MG1 when stopping the fuel injection of the engine 22 and stopping the rotation of the engine 22. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 120 according to a modification. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 220 of a modified example.

Explanation of symbols

  20, 120, 220 Hybrid vehicle, 22 engine, 23a crank position sensor, 24 engine electronic control unit (engine ECU), 26 crankshaft, 28 damper, 30 power distribution and integration mechanism, 31 sun gear, 32 ring gear, 32a ring gear shaft, 33 pinion gear, 34 carrier, 35 reduction gear, 40 motor electronic control unit (motor ECU), 41, 42 inverter, 43, 44 rotational position detection sensor, 50 battery, 51 temperature sensor, 52 battery electronic control unit (battery ECU) ), 54 power line, 60 gear mechanism, 62 differential gear, 63a, 63b driving wheel, 64a, 64b wheel, 70 hybrid electronic control unit, 72 CPU, 74 ROM, 76 AM, 80 ignition switch, 81 shift lever, 82 shift position sensor, 83 accelerator pedal, 84 accelerator pedal position sensor, 85 brake pedal, 86 brake pedal position sensor, 88 vehicle speed sensor, 90 brake master cylinder, 92 brake actuator, 94 brake Electronic control unit (brake ECU), 96a to 96d, brake wheel cylinder, 230 rotor motor, 232 inner rotor, 234 outer rotor, MG1, MG2 motor.

Claims (7)

An internal combustion engine device comprising an internal combustion engine and an electric motor capable of outputting torque to an output shaft of the internal combustion engine,
Engine speed detecting means for detecting an engine speed which is the speed of the internal combustion engine;
When the fuel supply to the internal combustion engine is stopped to stop the rotation of the internal combustion engine, a predicted zero arrival time, which is a time when the engine speed is predicted to reach zero based on the detected engine speed, The rotation reduction control is performed to control the electric motor so that a rotation reduction torque as a torque for reducing the engine speed is output from the electric motor before the estimated zero arrival predicted time reaches a predetermined time or less. Then, after the estimated zero arrival predicted time has reached the predetermined time or less, stop control for controlling the electric motor so that a stopping torque as a torque for stopping the internal combustion engine at a target stop position is output from the electric motor. A stop time control means for executing
An internal combustion engine device comprising:   The stop-time control means is means for executing the stop control when the detected engine speed is equal to or lower than a predetermined speed even before the estimated zero arrival predicted time reaches the predetermined time or shorter. The internal combustion engine device according to claim 1.   3. The stop time control means is means for executing the rotation reduction control regardless of the estimated zero arrival predicted time when the detected engine speed is equal to or higher than a second predetermined speed. The internal combustion engine device described.   The stop-time control means is means for executing the rotation reduction control or the stop control based on the estimated zero arrival predicted time after executing the rotation reduction control over a second predetermined time. Item 3. The internal combustion engine device according to Item 1 or 2.   The stop-time control means calculates an engine speed change rate that is a change amount of the engine speed per unit time based on the detected engine speed, and based on the calculated engine speed change rate. The internal combustion engine device according to any one of claims 1 to 4, which is means for estimating a zero arrival predicted time. A power output device that outputs power to a drive shaft,
An internal combustion engine device according to any one of claims 1 to 5,
Connected to the three shafts of the output shaft of the internal combustion engine, the drive shaft, and the rotating shaft of the electric motor, power is applied to the remaining shaft based on the power input / output to / from any two of the three shafts. 3-axis power input / output means for outputting;
Unlike the electric motor, a second electric motor capable of outputting torque to the drive shaft;
Power storage means capable of exchanging electric power with the electric motor and the second electric motor;
The internal combustion engine, the electric motor, and the second electric motor so that when the operation of the internal combustion engine is stopped, the internal combustion engine functions as the stop-time control means, and torque based on the required torque to be output to the drive shaft is output to the drive shaft. Control means for controlling
A power output device comprising: A control method for an internal combustion engine device comprising an internal combustion engine and an electric motor capable of outputting torque to an output shaft of the internal combustion engine,
When the fuel supply to the internal combustion engine is stopped to stop the rotation of the internal combustion engine, zero is the time that the engine speed is expected to reach zero based on the engine speed that is the speed of the internal combustion engine Rotation for estimating the arrival prediction time and controlling the electric motor so that a rotation reduction torque as a torque for reducing the engine speed is output from the electric motor before the estimated zero arrival prediction time reaches a predetermined time or less. After the reduction control is executed and the estimated zero arrival predicted time reaches the predetermined time or less, the motor is controlled so that a stopping torque as a torque for stopping the internal combustion engine at the target stop position is output from the motor. Execute stop control to control,
A control method for an internal combustion engine device.

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