JP2006347430A - Hybrid car and its control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve responsiveness when shifting such a state that while the operation of an internal combustion engine is maintained, fuel cut is executed to such a state that the fuel cut is stopped, and power is outputted. <P>SOLUTION: When requested power P* is predetermined power Pref or larger, the target periodicity Ne* and target torque Te* of an engine are set based on the request power P*, and the target valve timing VVT of an intake valve is set as timing corresponding to the operating state of an engine (S130, S140), and when the request power P* is the predetermined power Pref or smaller, and a speed V is a predetermined speed Vref or lower, the most delayed angle is set in target valve timing VTT to stop the operation of the engine (S180), and when the speed V is the predetermined speed Vref or higher, and the fuel cut is executed while maintaining the operation of the engine, the target valve timing VVT is set as an angle different form the most delayed angle (S210). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a hybrid vehicle that can be driven by power from at least one of power from an internal combustion engine and power from an electric motor, and a control method thereof.

Conventionally, as this type of hybrid vehicle, one having a hydraulic variable valve timing device has been proposed (see, for example, Patent Document 1). In this hybrid vehicle, when the engine is automatically stopped, the rotation phase of the camshaft is changed to the most retarded angle, and the fuel cut is performed when the change to the most retarded angle is completed, while suppressing the occurrence of vibration. The engine can be stopped.
JP 2001-289086 A

  By the way, in the hybrid vehicle, while the engine is stopped and the engine is stopped only by the motor, the hybrid vehicle can be driven in a fuel cut state while maintaining the operation (rotation) of the engine. In this case as well, it can be considered that the rotational phase of the camshaft is set to the most retarded angle as in the case of stopping the operation of the engine, thereby suppressing the occurrence of a shock at the time of fuel cut. However, if the rotational phase of the camshaft is set to the most retarded angle at the time of fuel cut, there may be a case where the required power cannot be handled when a relatively large power is required thereafter. In a hybrid vehicle with a variable valve timing device, changing the rotational phase of the camshaft involves a mechanical action, so the rotational phase of the camshaft is the most retarded when the accelerator pedal is depressed from the fuel cut state. Therefore, it takes time to advance to the rotation phase suitable for the output of power, and the power that matches the required power cannot be output quickly from the engine.

  The hybrid vehicle and the control method thereof according to the present invention further improve the output responsiveness when the operation of the internal combustion engine is appropriately stopped and the fuel injection in the internal combustion engine is stopped to the state where power is output from the internal combustion engine. The purpose is to improve.

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

The hybrid vehicle of the present invention
A hybrid vehicle capable of traveling with power from at least one of power from an internal combustion engine and power from an electric motor,
Requested power setting means for setting the requested power based on the operation of the driver;
Operation control means for controlling the internal combustion engine and the electric motor so that the internal combustion engine and the electric motor are operated based on the set required power;
When the operation of the internal combustion engine is stopped while running, the internal combustion engine is controlled so that a predetermined change accompanied by a mechanical operation is made to the operation state of the internal combustion engine, and the operation of the internal combustion engine is controlled. When stopping the fuel injection with maintenance, the internal combustion engine is set so that the operating state of the internal combustion engine is at least less changed than when the internal combustion engine is stopped. The gist of the present invention is to provide a control device at the time of stopping.

  In the hybrid vehicle of the present invention, the required power is set based on the operation of the driver, and the internal combustion engine and the electric motor are controlled so that the internal combustion engine and the electric motor are operated based on the set required power. When the operation of the internal combustion engine is stopped, the internal combustion engine is controlled so that a predetermined change accompanied by a mechanical operation is made to the operation state of the internal combustion engine, and the fuel injection is stopped while maintaining the operation of the internal combustion engine. In doing so, the internal combustion engine is controlled so that the degree of change in the predetermined change is smaller than at least when the operation state of the internal combustion engine is stopped. Therefore, it is possible to appropriately stop the operation of the internal combustion engine and further improve the output responsiveness when shifting from the state of maintaining the operation of the internal combustion engine with the stop of fuel injection to the state of outputting power from the internal combustion engine. Can do. Here, “to control the internal combustion engine so that the degree of change in the predetermined change is smaller than at least when the operation of the internal combustion engine is stopped” is more than when the operation of the internal combustion engine is stopped. In addition to the case where the operating state of the internal combustion engine is changed within a range where the degree of change in the predetermined change is small, the case where the operating state of the internal combustion engine is not changed is included.

  In such a hybrid vehicle of the present invention, the predetermined change may be a change that requires a predetermined time or more in the change of the operating state of the internal combustion engine.

  In the hybrid vehicle of the present invention, the predetermined change may be a change accompanied by a change in the opening / closing timing of the intake valve. In this case, when the operation of the internal combustion engine is stopped, the stop-time control means controls the internal combustion engine so that the opening / closing timing of the intake valve is positioned at a predetermined timing on the retard side, thereby operating the internal combustion engine. When the fuel injection is stopped with the maintenance of this, the internal combustion engine is controlled so that the opening / closing timing of the intake valve is positioned at a timing at which the degree of retardation is smaller than at least the predetermined timing. You can also. In these cases, there is provided a fixing means for fixing the opening / closing timing of the intake valve with a mechanical operation when the opening / closing timing of the intake valve is located at a predetermined timing, and the stop-time control means stops the operation of the internal combustion engine. The internal combustion engine is controlled so that the opening / closing timing of the intake valve is positioned at the predetermined timing, and the opening / closing timing of the intake valve is set to the predetermined timing when the fuel injection is stopped while maintaining the operation of the internal combustion engine. The internal combustion engine may be controlled so as to be positioned at a timing different from the above timing. In this way, it is possible to prevent the timing of the intake valve from being fixed by the fixing means when maintaining the operation of the internal combustion engine with the stop of the fuel injection, and thereafter, output of power from the internal combustion engine is required. In this case, the time required for releasing the fixing by the fixing means can be eliminated, and the output responsiveness can be further improved.

  Further, in the hybrid vehicle of the present invention, it is connected to the output shaft of the internal combustion engine and a drive shaft connected to the axle, and at least part of the power from the internal combustion engine is input to the drive shaft by input and output of electric power and power. It can also be provided with output power power input / output means. In this case, the power / power input / output means is connected to three axes of the output shaft, the drive shaft, and the third shaft of the internal combustion engine, and is based on power input / output to any two of the three shafts. In addition, a three-axis power input / output means for inputting / outputting power to / from the remaining one shaft may be provided, and the power / power input / output means is connected to the output shaft of the internal combustion engine. A counter-rotor electric motor having a rotor and a second rotor connected to the drive shaft, and relatively rotating the first rotor and the second rotor by electromagnetic action It can also be.

The hybrid vehicle control method of the present invention includes:
A method for controlling a hybrid vehicle capable of traveling with power from at least one of power from an internal combustion engine and power from an electric motor,
(A) The required power is set based on the driver's operation,
(B) controlling the internal combustion engine and the electric motor so that the internal combustion engine and the electric motor are operated based on the set required power,
(C) when the operation of the internal combustion engine is stopped while traveling, the internal combustion engine is controlled so that a predetermined change accompanied by a mechanical operation is made in the operation state of the internal combustion engine; When the fuel injection is stopped while maintaining the operation of the engine, the operating state of the internal combustion engine is set to a state in which the degree of change in the predetermined change is smaller than at least when the operation of the internal combustion engine is stopped. The gist is to control the internal combustion engine.

  In the hybrid vehicle of the present invention, the required power is set based on the operation of the driver, and the internal combustion engine and the electric motor are controlled so that the internal combustion engine and the electric motor are operated based on the set required power. When the operation of the internal combustion engine is stopped, the internal combustion engine is controlled so that a predetermined change accompanied by a mechanical operation is made to the operation state of the internal combustion engine, and the fuel injection is stopped while maintaining the operation of the internal combustion engine. In doing so, the internal combustion engine is controlled so that the degree of change in the predetermined change is smaller than at least when the operation state of the internal combustion engine is stopped. Therefore, it is possible to appropriately stop the operation of the internal combustion engine and further improve the output responsiveness when shifting from the state of maintaining the operation of the internal combustion engine with the stop of fuel injection to the state of outputting power from the internal combustion engine. Can do. Here, “to control the internal combustion engine so that the degree of change in the predetermined change is smaller than at least when the operation of the internal combustion engine is stopped” is more than when the operation of the internal combustion engine is stopped. In addition to the case where the operating state of the internal combustion engine is changed within a range where the degree of change in the predetermined change is small, the case where the operating state of the internal combustion engine is not changed is included.

  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 the configuration of a hybrid vehicle 20 according to an embodiment of the present invention, and FIG. 2 is a configuration diagram showing an outline of the configuration of an engine 22. 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, And a hybrid electronic control unit 70 for controlling the entire power output apparatus.

  The engine 22 is configured as an internal combustion engine capable of outputting power using a hydrocarbon-based fuel such as gasoline or light oil, and the air purified by an air cleaner 122 is passed through a throttle valve 124 as shown in FIG. Inhaled and gasoline is injected from the fuel injection valve 126 to mix the sucked air and gasoline, and this mixture is sucked into the fuel chamber through the intake valve 128 and explosively burned by an electric spark from the spark plug 130. Thus, the reciprocating motion of the piston 132 pushed down by the energy is converted into the rotational motion of the crankshaft 26. Exhaust gas from the engine 22 is discharged to the outside air through a purification device (three-way catalyst) 134 that purifies harmful components such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx).

  The engine 22 also includes a variable valve timing mechanism 150 that can continuously change the opening / closing timing of the intake valve 128. 3 and 4 are configuration diagrams showing an outline of the configuration of the variable valve timing mechanism 150. FIG. The variable valve timing mechanism 150 is fixed to the intake camshaft 129 that opens and closes the intake valve 128 and the housing portion 152a fixed to the timing gear 164 connected to the crankshaft 26 via the timing chain 162, as shown in the figure. A vane-type VVT controller 152 including a vane portion 152b and an oil control valve 156 that applies hydraulic pressure to the advance chamber and the retard chamber of the VVT controller 152 are provided, and the advance of the VVT controller 152 is provided via the oil control valve 156. By adjusting the hydraulic pressure applied to the corner chamber and the retard chamber, the vane portion 152b is rotated relative to the housing portion 152a to continuously adjust the angle of the intake camshaft 129 at the opening / closing timing of the intake valve 128. Further to. FIG. 5 shows an example of the opening / closing timing of the intake valve 128 when the angle of the intake camshaft 129 is advanced and the opening / closing timing of the intake valve 128 when the angle of the intake camshaft 129 is retarded. In the embodiment, the angle of the intake camshaft 129 at the opening / closing timing of the intake valve 128 where power is efficiently output from the engine 22 is used as a reference angle, and the angle of the intake camshaft 129 is advanced from the reference angle. The engine 22 can be in an operation state in which high torque can be output, and by reducing the angle of the intake camshaft 129, the pressure fluctuation in the cylinder of the engine 22 is reduced, and the operation of the engine 22 is stopped or started. It is comprised so that it can be set as the suitable driving | running state.

  Further, a lock pin 154 for fixing relative rotation between the housing portion 152a and the vane portion 152b is attached to the vane portion 152b of the VVT controller 152. FIG. 6 is a configuration diagram showing an outline of the configuration of the lock pin 154. As shown in the figure, the lock pin 154 includes a lock pin main body 154a and a spring 154b attached so that the lock pin main body 154a is biased toward the housing portion 152a, and the angle of the intake camshaft 129 is the most retarded angle. When it is positioned, the spring 154b is engaged with the groove 158 formed in the housing portion 152a by the spring force of the spring 154b to fix the vane portion 152b to the housing portion 152a. The lock pin 154 is a hydraulic actuator (not shown) so that the lock pin body 154a fitted in the groove 158 can be pulled out by applying a hydraulic pressure that overcomes the spring force of the spring 154b via the oil passage 159. Is provided.

  The engine 22 is controlled by an engine electronic control unit (hereinafter referred to as an engine ECU) 24. Signals from various sensors that detect the state of the engine 22 are input to the engine ECU 24 via an input port (not shown). For example, the engine ECU 24 performs intake / exhaust of the crank position from the crank position sensor 140 that detects the rotational position of the crankshaft 26 and the coolant temperature from the water temperature sensor 142 that detects the coolant temperature of the engine 22 and the combustion chamber. The cam position from the cam position sensor 144 that detects the rotational position of the intake camshaft 129 of the intake valve 128 and the exhaust camshaft that opens and closes the exhaust valve, and the throttle position from the throttle valve position sensor 146 that detects the opening of the throttle valve 124 The amount of intake air from an air flow meter 148 attached to the intake system of the engine 22 is input through the input port. Further, various control signals for driving the engine 22 are output from the engine ECU 24 via an output port (not shown). For example, the engine ECU 24 sends a drive signal to the fuel injection valve 126, a drive signal to the throttle motor 136 that adjusts the position of the throttle valve 124, a control signal to the ignition coil 138 integrated with the igniter, and variable valve timing. A control signal or the like to the mechanism 150 is output via the output port. 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 outputs data related to the operation state of the engine 22 as necessary. .

  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 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 the 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. The battery ECU 52 also calculates the remaining capacity (SOC) based on the integrated value of the charge / discharge current detected by the current sensor in order to manage the battery 50.

  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. As described above, the hybrid electronic control unit 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via the communication port, and exchanges various control signals and data with the engine ECU 24, the motor ECU 40, and the battery ECU 52. ing.

  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 corresponding to the depression amount of the accelerator pedal 83 by the driver and the vehicle speed V. 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 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 and 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 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 thus configured hybrid vehicle 20 of the embodiment will be described. FIG. 7 is a flowchart showing an example of a drive control routine executed by the hybrid electronic control unit 70. This routine is repeatedly executed every predetermined time (for example, every several msec).

  When the drive 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 vehicle speed V from the vehicle speed sensor 88, the rotational speed Nm1, of the motors MG1, MG2. A process of inputting data necessary for control, such as Nm2, remaining capacity SOC of the battery 50, is executed (step S100). Here, the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 are input from the motor ECU 40 by communication from those calculated based on the rotational positions of the rotors of the motors MG1 and MG2 detected by the rotational position detection sensors 43 and 44. To do. Further, the remaining capacity SOC of the battery 50 is calculated from the charge / discharge current of the battery 50 detected by the current sensor, and is input from the battery ECU 52 by communication.

  When the data is thus input, the required torque Tr * to be output to the ring gear shaft 32a as the drive shaft connected to the drive wheels 63a and 63b as the torque required for the vehicle based on the input accelerator opening Acc and the vehicle speed V. And the required power P * required for the vehicle is set (step S110). In the embodiment, the required torque Tr * is determined in advance by storing the relationship between the accelerator opening Acc, the vehicle speed V, and the required torque Tr * in the ROM 74 as a required torque setting map, and the accelerator opening Acc, the vehicle speed V, , The corresponding required torque Tr * is derived and set from the stored map. FIG. 8 shows an example of the required torque setting map. The required power P * can be calculated as the sum of a value obtained by multiplying the set required torque Tr * by the rotation speed Nr of the ring gear shaft 32a and the charge / discharge required power Pb * required by the battery 50 and the loss Loss. The rotation speed Nr of the ring gear shaft 32a can be obtained by multiplying the vehicle speed V by the conversion factor k, or can be obtained by dividing the rotation speed Nm2 of the motor MG2 by the gear ratio Gr of the reduction gear 35. The charge / discharge required power Pb * can be set based on the remaining capacity SOC of the battery 50 and the accelerator opening Acc.

  When the required power P * is set, the set required power P * is compared with the predetermined power Pref (step S120). Here, the predetermined power Pref determines a region in which power should be output from the engine 22, and is determined by characteristics of the engine 22 and the motor MG2. When the required power P * is determined to be equal to or higher than the predetermined power Pref, the target rotational speed Ne * and the target torque Te * of the engine 22 are set based on the required power P * and an operation line for operating the engine 22 efficiently. (Step S130). FIG. 9 shows an example of the operation line of the engine 22 and how the target rotational speed Ne * and the target torque Te * are set. As shown in the figure, the target rotational speed Ne * and the target torque Te * can be obtained from the intersection of the operation line and a curve having a constant required power P * (Ne * × Te *).

  When the target rotational speed Ne * and the target torque Te * are set, the target valve timing VVT of the intake valve 128 in the variable valve timing mechanism 150 is set based on the operating state of the engine 22 and instructed to the engine ECU 24 (step S140). . Here, in the target valve timing VVT, for example, when the target torque Te * is less than a predetermined torque, the angle of the intake camshaft 129 is set as a reference angle at which power can be efficiently output from the engine 22, and the target torque Te * is equal to or higher than the predetermined torque. Sometimes, the angle of the intake camshaft 129 can be set as an angle advanced by a predetermined angle from the reference angle so that high torque can be output from the engine 22.

  Then, using the set target rotational speed Ne *, the rotational speed Nr (Nm2 / Gr) of the ring gear shaft 32a, and the gear ratio ρ of the power distribution and integration mechanism 30, the target rotational speed Nm1 * of the motor MG1 is given by the following equation (1). And the torque command Tm1 * of the motor MG1 is calculated by the equation (2) based on the calculated target rotational speed Nm1 * and the current rotational speed Nm1 (step S220). Here, Expression (1) is a dynamic relational expression for the rotating element of the power distribution and integration mechanism 30. FIG. 10 is a collinear diagram showing the dynamic relationship between the rotational speed and torque in the rotating elements of the power distribution and integration mechanism 30. 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. Expression (1) can be easily derived by using this alignment chart. The two thick arrows on the R axis indicate that torque Te * output from the engine 22 when the engine 22 is normally operated at the operation point of the target rotational speed Ne * and the target torque Te * is transmitted to the ring gear shaft 32a. Torque and torque that the torque Tm2 * output from the motor MG2 acts on the ring gear shaft 32a via the reduction gear 35. Expression (2) is a relational expression in feedback control for rotating the motor MG1 at the target rotational speed Nm1 *. In Expression (2), “k1” in the second term on the right side is a gain of a proportional term. “K2” in the third term on the right side is the gain of the integral term.

Nm1 * = Ne * ・ (1 + ρ) / ρ-Nm2 / (Gr ・ ρ) (1)
Tm1 * = previous Tm1 * + k1 (Nm1 * -Nm1) + k2∫ (Nm1 * -Nm1) dt (2)

  When the target rotational speed Nm1 * and the torque command Tm1 * of the motor MG1 are thus calculated, the 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 calculated. Torque command Tm2 * is calculated by the equation (3) (step S230). Equation (3) can be easily derived from the collinear diagram of FIG. 10 described above.

  Tm2 * = (Tr * + Tm1 * / ρ) / Gr (3)

  Thus, when the target engine speed Ne *, the target torque Te *, and the torque commands Tm1 *, Tm2 * of the motors MG1, MG2 are set, the target engine speed Ne * and the target torque Te * of the engine 22 are set in the engine ECU 24. The torque commands Tm1 * and Tm2 * for the motors MG1 and MG2 are transmitted to the motor ECU 40 (step S240), and the drive control routine is terminated. The engine ECU 24 that has received the target rotational speed Ne * and the target torque Te * performs fuel injection control in the engine 22 such that the engine 22 is operated at an operating point indicated by the target rotational speed Ne * and the target torque Te *. Controls such as ignition control. The motor ECU 40 that has received the torque commands Tm1 * and Tm2 * controls the switching elements of the inverters 41 and 42 so that the motor MG1 is driven by the torque command Tm1 * and the motor MG2 is driven by the torque command Tm2 *. To do.

  If it is determined in step S120 that the required power P * is less than the predetermined power Pref, it is determined that the power is not output from the engine 22 and fuel cut is instructed to the engine ECU 24 (step S150). The predetermined vehicle speed Vref is compared (step S160). Here, the predetermined vehicle speed Vref is a threshold value for determining whether to maintain or stop the operation of the engine 22 in a fuel cut state. In the embodiment, when the operation of the engine 22 is stopped in a state where the vehicle speed V is high, the rotational speed of the sun gear 31 and the rotational speed of the motor MG1 become excessive due to the relationship of the gear ratio ρ of the power distribution and integration mechanism 30 shown in FIG. This is to avoid this because there are cases. When it is determined that the vehicle speed V is less than the predetermined vehicle speed Vref, it is determined that the operation of the engine 22 may be stopped, and a value of 0 is set for each of the target rotational speed Ne * and the target torque Te * of the engine 22 (step S170), the target valve timing VVT is set so that the angle of the intake camshaft 129 at the opening / closing timing of the intake valve 128 becomes the most retarded angle when the engine is stopped, and the engine ECU 24 is instructed (step S180), and the motor MG1 A value 0 is set in the torque command Tm1 * (step S190). Based on the required torque Tr *, the torque command Tm1 *, and the gear ratio ρ of the power distribution and integration mechanism 30, the torque command Tm2 * of the motor MG2 is set using the above-described equation (3) (step S230). The set value is transmitted to the engine ECU 24 and the motor ECU 40 (step S240), and this routine is finished. As a result, the angle of the intake camshaft 129 is positioned at the most retarded angle, and the operation of the engine 22 is stopped. Therefore, the occurrence of shock when stopping the operation of the engine 22 is suppressed. Further, as described above, when the angle of the intake camshaft 129 is at the most retarded angle, the angle is fixed by the lock pin 154.

  On the other hand, when it is determined that the vehicle speed V is equal to or higher than the predetermined vehicle speed, the lower limit rotational speed Nemin derived based on the vehicle speed V and the lower limit rotational speed setting map is maintained so that the operation of the engine 22 is maintained in a state where the fuel is cut. The target rotational speed Ne * is set to 22 and the value 0 is set to the target torque Te * of the engine 22 (step S200). An example of the lower limit rotational speed setting map is shown in FIG. When the target rotational speed Ne * and the target torque Te * of the engine 22 are set in this way, a reference for efficiently outputting power from the engine 22 with the angle of the intake camshaft 129 at the opening / closing timing of the intake valve 128 as an angle for fuel cut. The target valve timing VVT is instructed to the angle to the engine ECU 24 (step S210), and the above-described equation is based on the set target rotational speed Ne *, the rotational speed Nm2 of the motor MG2, and the gear ratio ρ of the power distribution and integration mechanism 30. The target rotational speed Nm1 * of the motor MG1 is set by (1), and the torque command Tm1 * of the motor MG1 is calculated by the above-described equation (2) based on the set target rotational speed Nm1 * and the current rotational speed Nm1 of the motor MG1. (Step S220), the required torque Tr * and the torque command Tm1 * Based on the gear ratio ρ of the force distribution and integration mechanism 30, the torque command Tm2 * of the motor MG2 is set by the above-described equation (3) (step S230), and each set value is transmitted to the engine ECU 24 and the motor ECU 40 (step S230). S240), this routine is finished. As described above, when the engine 22 is stopped by cutting the fuel, the angle of the intake camshaft 129 at the opening / closing timing of the intake valve 128 is retarded to the most retarded angle so that the operation of the engine 22 is not caused. Can be stopped. On the other hand, in the variable valve timing mechanism 150, the change of the opening / closing timing of the intake valve 128 is accompanied by a mechanical operation, so that the change takes time. Therefore, if the opening / closing timing of the intake valve 128 is set to the most retarded angle until the operation of the engine 22 is maintained with the fuel cut, the accelerator pedal 83 is depressed and the required power P * is equal to or higher than the predetermined power Pref. When the fuel cut is stopped and torque is output from the engine 22, it takes time to advance the opening / closing timing of the intake valve 128, and the ring gear shaft 32a as the drive shaft matches the required torque Tr *. Torque cannot be output quickly. Further, when the opening / closing timing of the intake valve 128 is set to the most retarded angle, the angle is fixed by the lock pin 154, so that it takes time to remove the lock pin 154. The opening / closing timing of the intake valve 128 is set to the most retarded angle when the operation of the engine 22 is stopped due to the fuel cut, but the opening / closing timing of the intake valve 128 is set as the reference angle when the operation of the engine 22 is maintained in the fuel cut state. Is based on these reasons. If it is determined in step S160 that the vehicle speed V is less than the predetermined vehicle speed Vref while the operation of the engine 22 is maintained with the fuel cut, the angle of the intake camshaft 129 at the opening / closing timing of the intake valve 128 is the latest. The operation of the engine 22 is stopped due to the corner.

  According to the hybrid vehicle 20 of the embodiment described above, the reference cam angle 129 as the angle of the intake camshaft 129 at the opening / closing timing of the intake valve 128 based on the operating state of the engine 22 while the engine 22 is operating. In addition, the variable valve timing mechanism 150 is controlled so as to be further advanced, and the engine 22 and the motors MG1, MG2 are controlled so that the required torque Tr * is output to the ring gear shaft 32a, and when the operation of the engine 22 is stopped, the intake valve 128 is stopped. When the variable valve timing mechanism 150 is controlled so that the angle of the intake camshaft 129 at the opening / closing timing of the engine is retarded to the most retarded angle as the engine stop angle, the intake air is maintained when the operation of the engine 22 is maintained with the fuel cut. When opening and closing the valve 128 Since the variable valve timing mechanism 150 is controlled so that the angle of the intake camshaft 129 becomes the reference angle, the occurrence of shock when stopping the operation of the engine 22 can be suppressed and the operation of the engine 22 can be performed by fuel cut. It is possible to further improve the output responsiveness when shifting from the maintained state to the state in which the fuel cut is stopped and the engine 22 outputs power. Moreover, when maintaining the operation of the engine 22 with the fuel cut, the output responsiveness can be further improved because the angle of the intake camshaft 129 is not fixed by the lock pin 154.

  In the hybrid vehicle 20 of the embodiment, when the operation of the engine 22 is maintained with the fuel cut, the target valve timing VVT of the intake valve 128 is set as a reference angle at which power can be efficiently output from the engine 22 using the angle for fuel cut. However, it is not always necessary to use the reference angle. If the angle is different from the most retarded angle used when stopping the operation of the engine 22, the fuel cut is stopped and power is output from the engine 22. Since the responsiveness can be improved, any angle may be used. For example, the target valve timing VVT when the engine 22 is operated immediately before the fuel cut may be maintained as it is, or any angle in the region between the reference angle and the most retarded angle It is good also as what. In these cases, as the angle of the intake camshaft 129 is set to the retard side, the occurrence of a shock when maintaining the operation of the engine 22 in the fuel cut state can be suppressed. The transition from the state to the state of outputting torque can be performed quickly.

  The hybrid vehicle 20 of the embodiment includes the lock pin 154 that is fixed at the angle of the intake cam shaft 129 when the intake valve 128 is opened and closed at the most retarded angle. It is good even if it does not have.

  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 220 of the modified example of FIG. May be connected to an axle (an axle connected to the wheels 64a and 64b in FIG. 12) different from the axle to which the ring gear shaft 32a is connected (the 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 320 includes an inner rotor 332 connected to the crankshaft 26 of the engine 22 and an outer rotor 334 connected to a drive shaft that outputs power to the drive wheels 63a and 63b. A counter-rotor electric motor 330 that transmits a part of the power to the drive shaft and converts the remaining power into electric power may be provided.

  In the hybrid vehicle 20 of the embodiment, the engine 22, the power distribution and integration mechanism 30, and the motors MG1 and MG2 are provided. However, as illustrated in the hybrid vehicle 420 of the modified example of FIG. A transmission 430 connected to the connected drive shaft and connected to the output shaft of the engine 22 via the clutch CL, and a motor 440 for inputting and outputting power to the input side of the transmission 430 may be provided. .

  The embodiments of the present invention have been described using the embodiments. However, the present invention is not limited to these embodiments, and can be implemented in various forms without departing from the gist of the present invention. Of course you get.

  The present invention is applicable to the automobile industry.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 according to an embodiment of the present invention. 2 is a configuration diagram showing an outline of the configuration of an engine 22. FIG. 2 is an external configuration diagram showing an external configuration of a variable valve timing mechanism 150. FIG. 2 is a configuration diagram showing an outline of a configuration of a variable valve timing mechanism 150. FIG. It is explanatory drawing which shows an example of the opening / closing timing of the intake valve 128 when the angle of the intake cam shaft 129 is advanced, and the opening / closing timing of the intake valve 128 when the angle of the intake cam shaft 129 is retarded. It is a block diagram which shows the outline of a structure of the lock pin 154. FIG. It is a flowchart which shows an example of the drive control routine performed by the electronic control unit for hybrids 70 of an Example. It is explanatory drawing which shows an example of the map for request | requirement torque setting. It is explanatory drawing which shows a mode that an example of the operating line of the engine 22, and target rotational speed Ne * and target torque Te * are set. FIG. 4 is an explanatory diagram showing an example of a collinear diagram for dynamically explaining rotational elements of a power distribution and integration mechanism 30. It is explanatory drawing which shows an example of the map for a minimum rotation speed setting. FIG. 6 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 220 according to a modification. FIG. 10 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 320 of a modified example. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 420 according to a modification.

Explanation of symbols

20, 220, 320, 420 Hybrid vehicle, 22 engine, 24 engine electronic control unit (engine ECU), 26 crankshaft, 28 damper, 30 power distribution integration mechanism, 31 sun gear, 32 ring gear, 32a ring gear shaft, 33 pinion gear, 34 carrier, 35, reduction gear, 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 drive wheel, 64a, 64b wheel, 70 hybrid electronic control unit, 72 CPU, 74 ROM, 76 RAM, 80 ignition switch, 81 shift Lever, 82 Shift position sensor, 83 Accelerator pedal, 84 Accelerator pedal position sensor, 85 Brake pedal, 86 Brake pedal position sensor, 88 Vehicle speed sensor, 122 Air cleaner, 124 Throttle valve, 126 Fuel injection valve, 128 Intake valve, 129 Intake cam Shaft, 130 Spark plug, 132 Piston, 134 Purifier, 136, Throttle motor, 138 Ignition coil, 140 Crank position sensor, 142 Water temperature sensor, 144 Cam position sensor, 146 Throttle valve position sensor, 148 Air flow meter, 150 Variable valve timing Mechanism, 152 VVT controller, 152a housing part, 152b vane part, 154 lock pin, 154a lock Pin body, 154b spring 156 oil control valve, 158 groove, 159 oil passage, 162 timing chain, 164 timing gears, 330 pair-rotor motor, 332 an inner rotor 334 outer rotor, 430 transmission, 440 motor, MG1, MG2 motor.

Claims (9)

A hybrid vehicle capable of traveling with power from at least one of power from an internal combustion engine and power from an electric motor,
Requested power setting means for setting the requested power based on the operation of the driver;
Operation control means for controlling the internal combustion engine and the electric motor so that the internal combustion engine and the electric motor are operated based on the set required power;
When the operation of the internal combustion engine is stopped while running, the internal combustion engine is controlled so that a predetermined change accompanied by a mechanical operation is made to the operation state of the internal combustion engine, and the operation of the internal combustion engine is controlled. When stopping the fuel injection with maintenance, the internal combustion engine is set so that the operating state of the internal combustion engine is at least less changed than when the internal combustion engine is stopped. A hybrid vehicle comprising: a control means at the time of stopping to control.   The hybrid vehicle according to claim 1, wherein the predetermined change is a change that requires a predetermined time or more in the change of the state of the internal combustion engine.   The hybrid vehicle according to claim 1 or 2, wherein the predetermined change is a change accompanied by a change in an intake valve opening / closing timing.   The stop-time control means controls the internal combustion engine so that the opening / closing timing of the intake valve is positioned at a predetermined timing on the retard side when stopping the operation of the internal combustion engine, and maintains the operation of the internal combustion engine. 4. The hybrid vehicle according to claim 3, which is means for controlling the internal combustion engine so that when the fuel injection is stopped, the opening / closing timing of the intake valve is positioned at a timing at which the degree of retardation is smaller than at least the predetermined timing. . A hybrid vehicle according to claim 3 or 4,
A fixing means for fixing the opening / closing timing with a mechanical operation when the opening / closing timing of the intake valve is positioned at a predetermined timing;
The stop-time control means controls the internal combustion engine so that the opening / closing timing of the intake valve is positioned at the predetermined timing when the operation of the internal combustion engine is stopped, and fuel is maintained with the maintenance of the operation of the internal combustion engine. A hybrid vehicle which is a means for controlling the internal combustion engine so that the opening / closing timing of the intake valve is positioned at a timing different from the predetermined timing when the injection is stopped.   Power power input / output means connected to the output shaft of the internal combustion engine and a drive shaft connected to the axle, and capable of outputting at least part of the power from the internal combustion engine to the drive shaft by input and output of power and power. A hybrid vehicle according to any one of claims 1 to 5.   The power power input / output means is connected to three shafts of the output shaft of the internal combustion engine, the drive shaft, and a third shaft, and the remaining power based on power input / output to any two of the three shafts. The hybrid vehicle according to claim 6, further comprising a triaxial power input / output means for inputting / outputting power to / from one shaft.   The power drive input / output means has a first rotor connected to the output shaft of the internal combustion engine and a second rotor connected to the drive shaft, and the first rotor and the first rotor The hybrid vehicle according to claim 6, wherein the hybrid vehicle is a counter-rotor motor that relatively rotates with the two rotors by electromagnetic action. A method for controlling a hybrid vehicle capable of traveling with power from at least one of power from an internal combustion engine and power from an electric motor,
(A) The required power is set based on the driver's operation,
(B) controlling the internal combustion engine and the electric motor so that the internal combustion engine and the electric motor are operated based on the set required power,
(C) when the operation of the internal combustion engine is stopped while traveling, the internal combustion engine is controlled so that a predetermined change accompanied by a mechanical operation is made in the operation state of the internal combustion engine; When the fuel injection is stopped while maintaining the operation of the engine, the operating state of the internal combustion engine is set to a state in which the degree of change in the predetermined change is smaller than at least when the operation of the internal combustion engine is stopped. A hybrid vehicle control method for controlling an internal combustion engine.

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