JP2009274671A - Hybrid vehicle and its control method - Google Patents

Abstract

In a hybrid vehicle including an internal combustion engine having an exhaust gas recirculation valve, abnormality diagnosis of the exhaust gas recirculation valve is accurately performed.
In a hybrid vehicle, a variable valve mechanism is operated by a variable valve mechanism when a valve timing change cancel condition is satisfied while an accelerator operation state by a driver is an accelerator off state and fuel injection to an engine is stopped. When an abnormality diagnosis execution condition is satisfied that includes the fact that a predetermined waiting time tref has elapsed since the advance timing of the opening timing of the intake valve 131 is released (steps S350, S370 and S380), the EGR valve 143 is turned on. Whether or not the EGR valve 143 is abnormal is diagnosed based on the state of fluctuation of the intake negative pressure Pi accompanying opening and closing of the EGR valve 143 (steps S400 to S420).
[Selection] Figure 7

Description

  The present invention relates to a hybrid vehicle including an internal combustion engine having an exhaust gas recirculation valve for recirculating exhaust gas from an exhaust system to an intake system, and a control method thereof.

Conventionally, as an internal combustion engine having an exhaust gas recirculation valve (exhaust gas recirculation control valve), the intake pipe pressure when the exhaust gas recirculation valve is forcibly opened during fuel supply stop and the exhaust gas recirculation valve during fuel supply stop Is known to have a self-diagnosis function that determines that an abnormality has occurred in the exhaust gas recirculation valve when the deviation from the intake pipe pressure when the valve is not forced to open the valve is below a predetermined value ( For example, see Patent Document 1). In addition, this type of internal combustion engine generates a drive signal with a predetermined duty ratio so that the exhaust gas recirculation valve has an arbitrary opening during the deceleration fuel cut, and the actual opening detected by the valve opening sensor after a predetermined time elapses. It is also known that an abnormality of the exhaust gas recirculation valve is determined when the relationship between the degree and the predetermined duty ratio deviates greatly from the planned relationship (see, for example, Patent Document 2).
JP-A-2-075748 Japanese Patent Laid-Open No. 6-299912

  Conventionally, an internal combustion engine, first and second motors, an engine shaft of the internal combustion engine, a rotation shaft of the first electric motor, and a predetermined axle (second electric motor) that transmits power to drive wheels. A hybrid vehicle having a power distribution and integration mechanism connected to three shafts is known. If an internal combustion engine having an exhaust gas recirculation device is applied to such a hybrid vehicle, the fuel consumption (fuel consumption rate) of the internal combustion engine can be reduced. It can be considered that the energy efficiency of the entire vehicle can be further improved. However, in this type of hybrid vehicle, when the accelerator operation state by the driver becomes the accelerator off state, the internal combustion engine is basically motored by the first electric motor in a state where the fuel supply is stopped. Accordingly, the variable valve mechanism of the internal combustion engine is controlled. Therefore, in the internal combustion engine mounted on the hybrid vehicle, the fluctuation of the pressure in the intake pipe in the accelerator off state becomes larger than that of the conventional internal combustion engine, and even if the same method is used as before, the exhaust gas is stopped when the fuel supply of the internal combustion engine is stopped. There is a possibility that abnormality diagnosis of the recirculation valve cannot be executed with high accuracy.

  Therefore, the main object of the present invention is to accurately perform an abnormality diagnosis of an exhaust gas recirculation valve in a hybrid vehicle including an internal combustion engine having an exhaust gas recirculation valve.

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

The hybrid vehicle according to the present invention is
An internal combustion engine having an exhaust gas recirculation valve for recirculating exhaust gas from the exhaust system to the intake system, and a variable valve mechanism capable of changing an opening / closing timing of at least one of the intake valve and the exhaust valve;
A first electric motor capable of inputting and outputting power;
Power connected to three axes of the engine shaft of the internal combustion engine, the rotating shaft of the first electric motor, and a predetermined axle for transmitting power to the drive wheels, and power input / output to / from any two of these three shafts Power distribution and integration means for inputting and outputting power based on the remaining shaft;
A second electric motor capable of inputting and outputting power to the axle or another axle different from the axle;
Power storage means capable of exchanging power with the first and second electric motors;
Requested driving force setting means for setting a requested driving force required for traveling according to the driver's accelerator operation;
The motoring of the internal combustion engine by the first electric motor and the internal combustion engine in a state where fuel supply is stopped until a predetermined valve timing change release condition is satisfied when the accelerator operation state by the driver is the accelerator off state Power based on the set required driving force can be obtained with a change in the opening / closing timing of at least one of the intake valve and the exhaust valve by the variable valve mechanism for promoting the intake of gas into the combustion chamber of the engine. In addition to controlling the internal combustion engine and the first and second electric motors, and after the valve timing change cancellation condition is satisfied when the accelerator operation state by the driver is the accelerator off state, the variable valve mechanism In the first electric motor in a state where the fuel supply is stopped without changing the opening / closing timing by An accelerator-off time control unit operable to control the internal combustion engine of motoring said internal combustion engine as the power based on the set required driving force is obtained with the first and second electric motor that,
While the accelerator operation state by the driver is the accelerator off state and the fuel supply to the internal combustion engine is stopped, the change of the opening / closing timing by the variable valve mechanism is caused by at least the establishment of the valve timing change release condition. The exhaust pipe recirculation valve is opened and closed when the predetermined abnormality diagnosis execution condition is satisfied, which includes that a predetermined waiting time has passed since the release, and the fluctuation in the intake pipe pressure due to the opening and closing of the exhaust gas recirculation valve An abnormality diagnosis means for diagnosing the presence or absence of abnormality of the exhaust gas recirculation valve based on the state;
Is provided.

  In this hybrid vehicle, the motoring of the internal combustion engine by the first electric motor in a state where the fuel supply is stopped until a predetermined valve timing change release condition is satisfied when the accelerator operation state by the driver is the accelerator off state. Power based on the required driving force required for travel with a change in the opening / closing timing of at least one of the intake valve and the exhaust valve by a variable valve mechanism for promoting the intake of gas into the combustion chamber of the internal combustion engine. The internal combustion engine and the first and second electric motors are controlled so as to obtain power. In addition, after the valve timing change release condition is satisfied when the accelerator operation state by the driver is the accelerator off state, the fuel supply is stopped without changing the opening / closing timing by the variable valve mechanism. The internal combustion engine and the first and second electric motors are controlled so that power based on the required driving force is obtained with motoring of the internal combustion engine by one electric motor. In this way, the fuel is sucked into the combustion chamber by changing the opening / closing timing of at least one of the intake valve and the exhaust valve until a predetermined valve timing change release condition is satisfied under the accelerator-off state. If the internal combustion engine in a state where the supply is stopped is motored by the first electric motor, it is possible to increase the friction torque by the internal combustion engine as much as possible and output the braking force according to the accelerator off to the axle while making effective use. It becomes. In this hybrid vehicle, when the accelerator operation state by the driver is the accelerator off state and the fuel supply to the internal combustion engine is stopped, at least the valve timing change canceling condition is satisfied, so that the variable valve mechanism opens and closes. The exhaust gas recirculation valve is opened and closed when a predetermined abnormality diagnosis execution condition is satisfied, which includes the fact that a predetermined waiting time has passed since the timing change was released. The presence or absence of an abnormality in the exhaust gas recirculation valve is diagnosed based on the pressure fluctuation state. That is, in this hybrid vehicle, after waiting for the pressure fluctuation in the intake pipe to stabilize after the change in the opening / closing timing of the intake valve or the like for accelerating the intake of gas into the combustion chamber in the accelerator off state, The exhaust gas recirculation valve is diagnosed for abnormality based on the fluctuation state of the intake pipe pressure. This makes it possible to accurately diagnose whether or not the exhaust gas recirculation valve is abnormal from the fluctuation state of the pressure in the intake pipe accompanying opening and closing of the exhaust gas recirculation valve. As the power distribution and integration means in this hybrid vehicle, a gear mechanism such as a three-element planetary gear mechanism or a differential gear can be used.

  The abnormality diagnosis execution condition is that the cooling water temperature of the internal combustion engine is equal to or higher than a predetermined temperature after the standby time has elapsed after the change in the opening / closing timing is canceled, and the fuel supply stop time is a predetermined time. It is a condition including the above requirements, that the closing time of the exhaust gas recirculation valve is not less than a predetermined time, and that the degree of change in the rotational speed of the engine shaft and the amount of intake air is not more than a predetermined degree, respectively. May be. As a result, it is possible to accurately perform an abnormality diagnosis of the exhaust gas recirculation valve in a state suitable for it.

  Further, the valve timing change cancellation condition may be a condition including a requirement that the engine speed is less than a predetermined value. This facilitates the intake of gas into the combustion chamber by changing the opening / closing timing of at least one of the intake valve and the exhaust valve while the rotational speed of the internal combustion engine is relatively high under the accelerator off state. It is possible to increase the friction torque due to the above as much as possible and to use it more effectively.

  The accelerator-off-time control means is configured such that when the accelerator operation state by the driver is an accelerator-off state, the internal combustion engine is motored by the first electric motor while the fuel supply is stopped. The internal combustion engine and the first and second electric motors may be controlled such that the shaft rotates at a target rotational speed determined according to the vehicle speed and power based on the required driving force is obtained.

  Further, the power distribution and integration means includes a first element connected to the engine shaft of the internal combustion engine, a second element connected to the rotation shaft of the first electric motor, and a first element connected to the predetermined axle. It may be a planetary gear mechanism having three elements and configured so that these three elements can be differentially rotated with respect to each other.

The hybrid vehicle control method according to the present invention includes:
An internal combustion engine having an exhaust gas recirculation valve for recirculating exhaust gas from the exhaust system to the intake system, and a variable valve mechanism capable of changing the opening / closing timing of at least one of the intake valve and the exhaust valve, and power input / output Connected to three shafts of a first motor, an engine shaft of the internal combustion engine, a rotating shaft of the first motor, and a predetermined axle for transmitting power to drive wheels, any two of these three shafts Power distribution integration means for inputting / outputting power based on power input / output to / from the remaining shaft, a second electric motor capable of inputting / outputting power to the axle or another axle different from the axle, and the first And a method for controlling a hybrid vehicle comprising a power storage means capable of exchanging electric power with a second electric motor,
(A) Motoring of the internal combustion engine by the first electric motor in a state where fuel supply is stopped until a predetermined valve timing change release condition is satisfied when the accelerator operation state by the driver is the accelerator off state And the power based on the set required driving force with the change of the opening / closing timing of at least one of the intake valve and the exhaust valve by the variable valve mechanism for promoting the intake of gas into the combustion chamber of the internal combustion engine. The internal combustion engine and the first and second electric motors are controlled so as to be obtained, and after the valve timing change cancellation condition is satisfied when the accelerator operation state by the driver is the accelerator off state, The first electric power in a state where the fuel supply is stopped without changing the opening / closing timing by a variable valve mechanism. And controlling said internal combustion engine and the first and second electric motor as motive power based on the set required driving force is obtained with a motoring of the internal combustion engine by the machine,
(B) While the accelerator operation state by the driver is the accelerator off state and the fuel supply to the internal combustion engine is stopped, the opening / closing timing by the variable valve mechanism is satisfied at least when the valve timing change release condition is satisfied. The exhaust gas recirculation valve is opened and closed and the exhaust pipe recirculation valve is opened and closed when a predetermined abnormality diagnosis execution condition is satisfied, which includes that a predetermined waiting time has passed since the change of Diagnosing the presence or absence of abnormality of the exhaust gas recirculation valve based on the pressure fluctuation state;
Is included.

  In this method, after the change in the opening / closing timing of the intake valve or the like for accelerating the intake of gas into the combustion chamber in the accelerator off state is waited for, the pressure fluctuation in the intake pipe stabilizes, The presence or absence of abnormality of the exhaust gas recirculation valve is diagnosed on the basis of the fluctuation state. This makes it possible to accurately diagnose whether or not the exhaust gas recirculation valve is abnormal from the fluctuation state of the pressure in the intake pipe accompanying opening and closing of the exhaust gas recirculation valve.

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

  FIG. 1 is a schematic configuration diagram of a hybrid vehicle 20 according to an embodiment of the present invention. A hybrid vehicle 20 shown in FIG. 1 includes an internal combustion engine device 21 including an engine 22, a three-shaft power distribution and integration mechanism 30 connected to a crankshaft (engine shaft) 26 of the engine 22 via a damper 28, A motor MG1 capable of generating electricity connected to the distribution integration mechanism 30, a reduction gear 35 attached to a ring gear shaft 32a as an axle connected to the power distribution integration mechanism 30, and the ring gear shaft 32a via the reduction gear 35. The motor MG2 is connected, and a hybrid electronic control unit (hereinafter referred to as “hybrid ECU”) 70 for controlling the entire hybrid vehicle 20 is provided.

  The engine 22 constituting the internal combustion engine device 21 explosively burns a mixture of hydrocarbon fuel such as gasoline or light oil and air in the combustion chamber 120, and cranks the reciprocating motion of the piston 121 accompanying the explosion combustion of the mixture. The engine is configured as an internal combustion engine that outputs power by converting it into a rotational motion of the shaft 26. In this engine 22, as can be seen from FIG. 2, the air purified by the air cleaner 122 is taken into the intake pipe 126 through the throttle valve 123, and fuel such as gasoline is injected from the fuel injection valve 127 into the intake air. The The air / fuel mixture thus obtained is sucked into the combustion chamber 120 via an intake valve 131 driven by a variable valve mechanism 130 configured as a variable valve timing mechanism, and is generated by an electric spark by a spark plug 128. Explosive burning. Exhaust gas from the engine 22 is an exhaust gas purification catalyst (three-way catalyst) that purifies harmful components such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx) through an exhaust valve 132 and an exhaust manifold 140. And purified by the purification device 141 and then discharged to the outside. The internal combustion engine device 21 is connected to an exhaust pipe downstream of the purification device 141 and recirculates exhaust gas to a surge tank (intake system), and is provided in the middle of the EGR pipe 142 and is connected to the exhaust system. An EGR valve 143 that adjusts the recirculation amount (EGR amount) of exhaust gas (EGR gas) recirculated to the intake system, a temperature sensor 144 that detects the temperature of the EGR gas in the EGR pipe 142, and the like are included.

  The engine 22 configured in this way is controlled by an engine electronic control unit (hereinafter referred to as “engine ECU”) 24. As shown in FIG. 2, the engine ECU 24 is configured as a microprocessor centered on a CPU 24a. In addition to the CPU 24a, a ROM 24b that stores various processing programs, a RAM 24c that temporarily stores data, and an input (not shown). Output port and communication port. Then, signals from various sensors that detect the state of the engine 22 and the like are input to the engine ECU 24 via an input port (not shown). For example, the engine ECU 24 includes a crank position from a crank position sensor 180 that detects the rotational position of the crankshaft 26, a cooling water temperature Tw from a water temperature sensor 181 that detects the temperature of cooling water in the engine 22, and a pressure in the combustion chamber 120. The cam from the cam position sensor 133 that detects the in-cylinder pressure from the in-cylinder pressure sensor 182 and the rotational position of the camshaft included in the variable valve mechanism 130 that can change the opening / closing timing of the intake valve 131 and the exhaust valve 132. Position, the throttle position from the throttle valve position sensor 124 that detects the position of the throttle valve 123, the intake air amount GA from the air flow meter 183 that detects the intake air amount as a load of the engine 22, and the intake air attached to the intake pipe 126 Temperature sensor The intake air pressure Pi from the intake pressure sensor 185 that detects the intake air temperature from the exhaust 184, the negative pressure in the intake pipe 126, the air-fuel ratio from the air-fuel ratio sensor 186 disposed upstream of the purification device 141 of the exhaust manifold 140 The EGR gas temperature and the like from the temperature sensor 144 of the AF and EGR pipe 142 are input via the input port. The engine ECU 24 outputs various control signals for driving the engine 22 through an output port (not shown). For example, the engine ECU 24 controls the drive signal to the fuel injection valve 127, the drive signal to the throttle motor 125 that adjusts the position of the throttle valve 123, the control signal to the ignition coil 129 integrated with the igniter, the variable valve mechanism 130. A control signal to the EGR valve, a drive signal to the EGR valve 143, and the like are output via an output port. Further, the engine ECU 24 is in communication with the hybrid ECU 70, controls the operation of the engine 22 by a control signal from the hybrid ECU 70, and outputs data related to the operation state of the engine 22 to the hybrid ECU 70 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 rotating elements. The carrier 34 as the first element has the crankshaft 26 of the engine 22, the sun gear 31 as the second element has the motor MG1, and the ring gear 32 as the third element has the reduction gear 35 via the ring gear shaft 32a. When the motor MG1 functions as a generator, the power distribution and integration mechanism 30 distributes the power from the engine 22 input from the carrier 34 to the sun gear 31 side and the ring gear 32 side according to the gear ratio. When the motor MG1 functions as an electric motor, the power from the engine 22 input from the carrier 34 and the power from the motor MG1 input from the sun gear 31 are integrated and output to the ring gear 32 side. The power output to the ring gear 32 is finally output from the ring gear shaft 32a to the wheels 39a and 39b, which are drive wheels, via the gear mechanism 37 and the differential gear 38.

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

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

  The hybrid ECU 70 is configured as a microprocessor centered on the CPU 72, and includes a ROM 74 for storing a processing program, a RAM 76 for temporarily storing data, an input / output port and a communication port (not shown), and the like in addition to the CPU 72. The hybrid ECU 70 detects the ignition signal from the ignition switch (start switch) 80, the shift position SP from the shift position sensor 82 that detects the shift position SP that is the operation position of the shift lever 81, and the depression amount of the accelerator pedal 83. The accelerator opening Acc from the accelerator pedal position sensor 84, the brake pedal stroke BS from the brake pedal stroke sensor 86 for detecting the depression amount of the brake pedal 85, the vehicle speed V from the vehicle speed sensor 87, and the like are input via the input port. . As described above, the hybrid ECU 70 is connected to the engine ECU 24, the motor ECU 40, the battery ECU 52, etc. via the communication port, and exchanges various control signals and data with the engine ECU 24, the motor ECU 40, the battery ECU 52, etc. ing. In the hybrid vehicle 20 of the embodiment, the shift position SP of the shift lever 81 includes a parking position (P position) used during parking, a reverse position for reverse travel (R position), and basically the engine 22 is stopped. Inverters 41 and 42 are shut down (all switching elements are turned off), neutral position (N position), normal forward drive position (D position), compared to when D position is selected under accelerator off state A brake position (B position) or the like is provided so that a large braking force can be obtained.

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

  Next, the operation when the hybrid vehicle 20 of the embodiment configured as described above is traveling will be described. FIG. 3 shows a hybrid ECU 70 of the embodiment when the driver releases the accelerator pedal 83 (when the accelerator is turned off) while the hybrid vehicle 20 is running with the operation of the engine 22. Is a flowchart showing an example of an accelerator-off time drive control routine executed every predetermined time (for example, every several milliseconds). When the driver depresses the accelerator pedal 83, a fuel cut command signal is transmitted from the hybrid ECU 70 to the engine ECU 24, and the engine ECU 24 that has received the fuel cut command signal pauses fuel injection control and ignition timing control. To do.

  3 is started, the CPU 72 of the hybrid ECU 70 determines the accelerator opening Acc from the accelerator pedal position sensor 84, the shift position SP from the shift position sensor 82, the vehicle speed V from the vehicle speed sensor 87, the engine. Input processing of data necessary for control such as the rotational speed Ne of 22 (crankshaft 26), the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2, and the input and output limits Win and Wout of the battery 50 is executed (step S100). Here, the rotation speed Ne of the engine 22 is calculated based on the crank position from the crank position sensor 180 and is input from the engine ECU 24 by communication. The rotation speeds Nm1 and Nm2 of the motors MG1 and MG2 are Input from the ECU 40 by communication. The input / output limits Win and Wout of the battery 50 are input from the battery ECU 52 by communication. After the data input process in step S100, a request to be output to the ring gear shaft 32a in the state where the accelerator pedal 83 is released, that is, in the accelerator off state, based on the accelerator opening Acc, the vehicle speed V, and the shift position SP that are input. Torque Tr * is set (step S110). In the embodiment, the relationship among the accelerator opening Acc, the vehicle speed V, the shift position SP, and the required torque Tr * in the accelerator-off state is determined in advance and stored in the ROM 74 as an accelerator-off required torque setting map. A value corresponding to the accelerator opening Acc, the vehicle speed V, and the shift position SP is derived and set as the required torque Tr * from the map. FIG. 4 shows an example of a map for setting required torque when the accelerator is off. As can be seen from the figure, in the hybrid vehicle 20 of the embodiment, the required torque Tr * when the accelerator is off is basically set to a smaller value (a larger value as the braking torque) as the vehicle speed V is higher. When the shift position SP is the B position, the required torque Tr * is set to a smaller value (a larger value as the braking torque) than when the D position is selected.

  Next, it is determined whether or not the rotational speed Ne of the engine 22 input in step S100 is greater than or equal to a predetermined reference rotational speed Neref (step S120). The reference rotational speed Neref used as the threshold value in step S120 is a state in which fuel is cut when the braking torque is output to the ring gear shaft 32a serving as the axle as the accelerator operation state of the driver becomes the accelerator off state. This corresponds to the lower limit value of the rotational speed at which the friction torque from the engine 22 can be satisfactorily used. In the embodiment, for example, the value is about 2000 rpm. If the rotational speed Ne is equal to or higher than the reference rotational speed Neref, in the embodiment, the opening timing of the intake valve 131 is advanced from the reference timing so that the intake of the gas in the intake pipe 126 to the combustion chamber 120 is promoted. Therefore, a predetermined VVT advance request flag Fva is set to a value 1 (step S130). If the rotational speed Ne is less than the reference rotational speed Neref, in the embodiment, the VVT advance request flag Fva is set to a value 0 so that the opening timing of the intake valve 131 becomes the reference timing (step S140). . After the process of step S130 or S140, the target rotational speed Ne * of the engine 22 is set based on the vehicle speed V input in step S100 (step S150). In the embodiment, the relationship between the vehicle speed V in the accelerator-off state and the target engine speed Ne * of the engine 22 is determined in advance and stored in the ROM 74 as a map for setting the target engine speed at the time of accelerator-off. Is derived from the map and set as the target rotational speed Ne *. FIG. 5 shows an example of a map for setting the target engine speed when the accelerator is off. The accelerator off target rotation speed setting map illustrated in FIG. 6 determines the relationship between the rotation speed Ne and the friction torque obtained from the fuel-cut engine 22 in advance by experiment and analysis, and also requires the required braking torque. By assigning the target rotational speed Ne * for each vehicle speed V in consideration of the above, basically, the higher the vehicle speed V, the larger the target rotational speed Ne * is defined.

  If the target rotational speed Ne * of the engine 22 is thus set, the 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 number of teeth of the sun gear 31 / The target rotational speed Nm1 * of the motor MG1 is calculated according to the following formula (1) using the number of teeth of the ring gear 32), and the following formula (2) using the target rotational speed Nm1 *, the current rotational speed Nm1, etc. ), A torque command Tm1 * for the motor MG1 is set (step S160). Here, Expression (1) is a dynamic relational expression regarding the rotating elements of the power distribution and integration mechanism 30. FIG. 6 illustrates a collinear diagram showing a dynamic relationship between the rotational speed and torque in the rotary element of the power distribution and integration mechanism 30. In the figure, the left S-axis indicates the rotational speed of the sun gear 31 that matches the rotational speed Nm1 of the motor MG1, the central C-axis indicates the rotational speed of the carrier 34 that matches the rotational speed Ne of the engine 22, and the right R-axis. The axis indicates the rotational speed Nr of the ring gear 32 obtained by dividing the rotational speed Nm2 of the motor MG2 by the gear ratio Gr of the reduction gear 35. The two thick arrows on the R axis indicate the torque acting on the ring gear shaft 32a by this torque output when the motor MG1 outputs the torque Tm1, and the reduction gear 35 when the motor MG2 outputs the torque Tm2. And the torque acting on the ring gear shaft 32a via. Expression (1) for obtaining the target rotational speed Nm1 * of the motor MG1 can be easily derived by using the rotational speed relationship in this alignment chart. Expression (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 the proportional term. “K2” in the third term on the right side is the gain of the integral term.

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

  If torque command Tm1 * for motor MG1 is set, input / output limits Win and Wout of battery 50, torque command Tm1 * for motor MG1 set in step S160, and current rotational speeds Nm1 and Nm2 of motors MG1 and MG2 Are used to calculate torque limits Tmin and Tmax as upper and lower limits of torque that may be output from the motor MG2 in accordance with the following equations (3) and (4) (step S170). Further, a temporary motor torque Tm2tmp which is a temporary value of torque to be output from the motor MG2 using the required torque Tr *, the torque command Tm1 *, the gear ratio ρ of the power distribution and integration mechanism 30 and the gear ratio Gr of the reduction gear 35. Is calculated according to the following equation (5) (step S180). Then, the torque command Tm2 * for the motor MG2 is set to a value obtained by limiting the temporary motor torque Tm2tmp with the torque limits Tmin and Tmax (step S190). Thus, by setting the torque command Tm2 * for the motor MG2, the torque output to the ring gear shaft 32a as the axle can be limited within the range of the input / output limits Win and Wout of the battery 50. Equation (5) can be easily derived from the alignment chart of FIG. If torque commands Tm1 * and Tm2 * for motors MG1 and MG2 are set in this way, torque commands Tm1 * and Tm2 * are transmitted to motor ECU 40 (step S200), and the processing after step S100 is executed again.

Tmin = (Win-Tm1 * ・ Nm1) / Nm2 (3)
Tmax = (Wout-Tm1 * ・ Nm1) / Nm2 (4)
Tm2tmp = (Tr * + Tm1 * / ρ) / Gr (5)

  Receiving the torque commands Tm1 * and Tm2 *, the motor ECU 40 controls the switching elements of the inverters 41 and 42 so that the motor MG1 is driven according to the torque command Tm1 * and the motor MG2 is driven according to the torque command Tm2 *. Do. As a result, the engine 22 with the fuel cut so that the crankshaft 26 rotates at the target rotational speed Ne * is motored by the motor MG1, so that the friction torque of the engine 22 is output to the ring gear shaft 32a as the axle. Thus, it is possible to input / output torque corresponding to the excess or deficiency of the friction torque with respect to the required torque Tr * from the motor MG2 to the ring gear shaft 32a as the axle. Further, while the above-described accelerator-off drive control routine is executed by the hybrid ECU 70, the engine ECU 24 inputs the value of the VVT advance angle request flag Fva from the hybrid ECU 70, and the VVT advance angle request flag Fva is a value 1. That is, when the accelerator is off and the rotational speed Ne of the engine 22 is equal to or higher than the reference rotational speed Neref, the opening timing of the intake valve 131 is advanced by a predetermined angle (for example, 30 °) from the reference timing. The variable valve mechanism 130 is controlled. As a result, the gas intake into the combustion chamber 120 is promoted by the advance angle of the opening timing of the intake valve 131 while the rotational speed Ne of the engine 22 is relatively high in the accelerator off state, and thereby the friction by the engine 22 is increased. The torque can be increased as much as possible and can be used more effectively. Further, when the VVT advance request flag Fva is 0, that is, when the accelerator 22 is in the accelerator off state and the engine speed Ne is less than the reference engine speed Neref, the engine ECU 24 determines that the opening timing of the intake valve 131 is The variable valve mechanism 130 is controlled so that the reference timing is reached without being advanced.

  Here, the hybrid vehicle 20 of the embodiment is provided with an EGR pipe 142 that recirculates exhaust gas to a surge tank and an EGR pipe 142 in order to improve fuel consumption, reduce NOx, and the like. EGR valve 143 that adjusts the recirculation amount of exhaust gas recirculated to the system, but the exhaust gas of engine 22 contains carbon components and the like, and the carbon components and the like in the exhaust gas are contained in the EGR valve If it adheres to form a so-called deposit, an operation failure such as sticking of the EGR valve body may occur. For this reason, in the hybrid vehicle 20 of the embodiment, the abnormality diagnosis of the EGR valve 143 is performed, for example, by one trip using the timing when the driver's accelerator operation state is the accelerator off state and the fuel injection to the engine 22 is stopped. It is executed once. Next, an EGR valve abnormality diagnosis routine executed for diagnosing whether or not the EGR valve 143 is abnormal will be described with reference to FIG. The EGR valve abnormality diagnosis routine of FIG. 7 is performed when the accelerator pedal 83 is released by the driver while the hybrid vehicle 20 is running with the operation of the engine 22 after the ignition switch 80 is turned on. When the accelerator is turned off, the engine ECU 24 of the embodiment executes it at predetermined time intervals.

  At the start of the EGR valve abnormality diagnosis routine of FIG. 7, the CPU 24a of the engine ECU 24 calculates the rotation speed Ne of the engine 22 based on the crank position from the crank position sensor 180, the intake air amount GA from the air flow meter 183, Input of data necessary for control, such as intake negative pressure Pi from intake pressure sensor 185, cooling water temperature Tw from water temperature sensor 181, fuel cut time tfc, elapsed time tvs after EGR valve fully closed, and VVT advance angle request flag Fva Processing is executed (step S300). Here, the fuel cut time tfc is an elapsed time after the fuel injection of the engine 22 is stopped with the release of the accelerator pedal 83, and is measured by a timer (not shown) included in the engine ECU 24. Further, the elapsed time tvs after the EGR valve is fully closed is an elapsed time after the EGR valve 143 is fully closed as the accelerator pedal 83 is released, and is measured by a timer (not shown) included in the engine ECU 24. After the data input process of step S300, when abnormality diagnosis of the EGR valve 143 is started, it is determined whether or not the diagnosis execution flag Fie set to the value 1 is the value 0 (step S310). If abnormality diagnosis of the EGR valve 143 is not started and the diagnosis execution flag Fie is 0, it is further determined whether or not the predetermined flag F is 0 (step S320), and the flag F is 0. If so, whether the VVT advance angle request flag Fva input in step S300 has changed from the value 1 to the value 0, that is, whether the advance timing of the opening timing of the intake valve 131 by the variable valve mechanism 130 has been released. Determination is made (step S330). When it is determined in step S330 that the VVT advance angle request flag Fva remains at the value 1 or 0, the diagnosis execution flag Fie is set to the value 0, and the abnormality diagnosis of the EGR valve 143 is completed. Is set to 0 (step S450), and the processing after step S300 is executed again.

  On the other hand, if it is determined in step S330 that the VVT advance request flag Fva has changed from the value 1 to the value 0, the flag F is set to the value 1 and a predetermined timer (not shown) is turned on ( Step S340), it is determined whether or not the measured time t of the timer is greater than or equal to a predetermined standby time tref (Step S350). Here, the time t of the timer that is turned on in step S340 is the advance of the opening timing of the intake valve 131 by the variable valve mechanism 130 after the VVT advance request flag Fva changes from the value 1 to the value 0. Indicates the elapsed time since the corner was released. Further, the standby time tref as a threshold value used in step S350 is required to stabilize the pressure fluctuation in the intake pipe 126 after the advance angle of the opening timing of the intake valve 131 by the variable valve mechanism 130 is released. The time is determined by experiment and analysis. In the embodiment, the time is, for example, about 1 second. If the measured time t is less than the waiting time tref, the diagnosis execution flag Fie is set to the value 0, and the diagnosis completion flag Fif set to the value 1 when the abnormality diagnosis of the EGR valve 143 is completed is set to the value 0. (Step S450), and the processing after Step S300 is executed again. If the flag F is set to a value of 1 in step S340, a negative determination is made in step S320 after the next execution of this routine, so that the process in step S340 is skipped.

  If it is determined in step S350 that the time t is greater than or equal to the waiting time tref, the flag F is set to 0 and the timer turned on in step S340 is turned off (step S360). ), It is determined whether or not other preconditions (abnormality diagnosis conditions) for starting the abnormality diagnosis of the EGR valve 143 are satisfied (steps S370 and S380). In the embodiment, after an affirmative determination is made in step S350, (1) the cooling water temperature Tw is equal to or higher than a predetermined temperature (for example, about 70 to 80 ° C.), and (2) the fuel cut time tfc is a predetermined time (for example, 1). (3) The elapsed time tvs after the EGR valve is fully closed of the EGR valve 143 is equal to or longer than a predetermined time (for example, 1 second), and (4) the unit time of the rotational speed Ne of the engine 22 (this routine) (1) that the amount of change per unit time (the execution cycle of this routine) is less than or equal to a predetermined amount, and (5) that the amount of change per unit time (the execution cycle of this routine) is less than or equal to the predetermined amount. When all the conditions of (5) are satisfied, an affirmative determination is made in step S380.

  If an affirmative determination is made in step S380, the diagnosis execution flag Fie is set to 1 (step S390), and an abnormality diagnosis for the EGR valve 143 (step 400) is executed. In step S400 of the embodiment, for example, the EGR valve 143 opens to a predetermined opening degree with the passage of time, and then the command value according to a predetermined opening change pattern so that the EGR valve 143 closes with the passage of time. Degr is set and transmitted to an unillustrated actuator (for example, a step motor) of the EGR valve 143, and the intake negative pressure Pi input in step S300 is within a predetermined normal range corresponding to the command value degr for the EGR valve 143. Whether or not it is included is determined, and when the intake negative pressure Pi is not included in the normal range, a counter (not shown) is incremented. After the process of step S400, it is determined whether or not the abnormality diagnosis of the EGR valve 143 is completed (step S410). If the abnormality diagnosis is not completed, the processes after step S300 are executed again. If the diagnosis execution flag Fie is set to a value of 1 in step S390, a negative determination is made in step S310 after the next execution of this routine, so the processing from step S320 to S390 is skipped. Is done.

  If it is determined in step S410 that the abnormality diagnosis of EGR valve 143 has been completed, the presence or absence of abnormality of EGR valve 143 is determined based on the result of the process in step S400 (step S420). In step S420 of the embodiment, if the count value of the counter used in step S400 is less than a predetermined value, it is determined that the EGR valve 143 is normal, and if the count value is equal to or greater than the predetermined value, the EGR valve 143 is turned on. It is determined that an abnormality has occurred. If it is determined in step S420 that an abnormality has occurred in the EGR valve 143, the EGR prohibition flag Fegrd is set to a value 1 to prohibit execution of EGR control, and is provided on an instrument panel (not shown). The warning lamp lighting command signal is transmitted to a meter ECU (not shown) that controls the display unit including the warning lamp so that the predetermined warning lamp is turned on (step S430). Then, after the process of step S420 or S430, the diagnosis execution flag Fie is set to a value of 0, the diagnosis completion flag Fif is set to a value of 1 (step S440), and this routine is terminated. When the diagnosis completion flag Fif is set to the value 1, the EGR valve abnormality diagnosis routine of FIG. 7 is not executed until the ignition switch 80 is turned off thereafter. It is reset when the ignition switch 80 is turned on.

  As described above, in the hybrid vehicle 20 of the embodiment, when the accelerator operation state by the driver is the accelerator off state, the engine speed Ne is less than the reference engine speed Neref (the valve timing change cancellation condition is (Until established), the opening timing of the intake valve 131 by the variable valve mechanism 130 for promoting the motoring of the engine 22 by the motor MG1 and the intake of gas to the combustion chamber 120 of the engine 22 in the fuel cut state is advanced. The engine 22 and the motors MG1 and MG2 are controlled so that torque (braking torque) based on the required torque Tr * is output to the ring gear shaft 32a as an axle with an angle (step S130 in FIG. 3). Further, when the speed Ne of the engine 22 becomes less than the reference speed Neref when the accelerator operation state by the driver is the accelerator off state (after the valve timing change cancellation condition is satisfied), the intake valve by the variable valve mechanism 130 The torque based on the required torque Tr * is generated as the axle with the motoring of the engine 22 by the motor MG1 in the fuel cut state without the advance timing of the release timing 131 (step S140 in FIG. 3). The engine 22 and the motors MG1 and MG2 are controlled so as to be output to 32a. As described above, the fuel cut is performed in the state in which the intake of the gas to the combustion chamber 120 is promoted by the advance angle of the opening timing of the intake valve 131 until the valve timing change release condition is satisfied under the accelerator off state. If the engine 22 is motored by the motor MG1, it is possible to increase the friction torque by the engine 22 as much as possible and to output the braking torque corresponding to the accelerator off to the ring gear shaft 32a as the axle while effectively using it.

  In the hybrid vehicle 20 according to the embodiment, the variable valve mechanism is established when the valve timing change cancellation condition is satisfied while the accelerator operation state by the driver is the accelerator off state and fuel injection to the engine 22 is stopped. When an abnormality diagnosis execution condition is satisfied, which includes that a predetermined waiting time tref has elapsed since the advance of the opening timing of the intake valve 131 by 130 is canceled (steps S350, S370 and S380 in FIG. 7) The EGR valve 143 is opened and closed, and the presence or absence of abnormality of the EGR valve 143 is diagnosed based on the fluctuation state of the intake negative pressure (intake pipe pressure) Pi accompanying the opening and closing of the EGR valve 143 (steps S400 to S420 in FIG. 7). ). That is, in the hybrid vehicle 20, the pressure fluctuation in the intake pipe 126 is stabilized after the advance timing of the opening timing of the intake valve 131 for accelerating the intake of gas into the combustion chamber 120 in the accelerator off state. After waiting, the presence or absence of abnormality of the EGR valve 143 is diagnosed based on the fluctuation state of the intake negative pressure Pi. As a result, it is possible to accurately diagnose whether or not the EGR valve 143 is abnormal from the fluctuation state of the intake negative pressure Pi accompanying opening and closing of the EGR valve 143. Further, as in the above-described embodiment, after a predetermined waiting time tref has elapsed after the advance timing of the opening timing of the intake valve 131 is released, the cooling water temperature Tw of the engine 22 is equal to or higher than the predetermined temperature, and the fuel cut time That tfc is greater than or equal to a predetermined time, Elapsed time tvs after EGR valve is fully closed is greater than or equal to a predetermined time, and that the degree of change in engine speed Ne and intake air amount GA is less than or equal to a predetermined degree, respectively. If the abnormality diagnosis (step S400) of the EGR valve 143 is performed when all the conditions are satisfied, the abnormality diagnosis of the EGR valve 143 can be accurately executed in a state suitable for it. Further, if the valve timing change cancellation condition is established when the engine speed Ne is less than the reference engine speed Neref, the intake valve is operated while the engine speed Ne is relatively high under the accelerator off state. The advance of the opening timing of 131 facilitates the intake of gas into the combustion chamber 120, whereby the friction torque by the engine 22 can be increased as much as possible and can be used more effectively.

  In order to promote the intake of gas into the combustion chamber 120, the opening timing of the intake valve 131 is advanced instead of the opening timing of the intake valve 131 as in the above embodiment, or the exhaust valve is advanced. Needless to say, the closing timing of 132 may be delayed. In the hybrid vehicle 20 of the above embodiment, the ring gear shaft 32a as the axle and the motor MG2 are connected via the reduction gear 35 that reduces the rotational speed of the motor MG2 and transmits it to the ring gear shaft 32a. Instead of the gear 35, for example, a transmission that changes the rotational speed of the motor MG2 having two or three shift stages of Hi and Lo and transmits it to the ring gear shaft 32a may be employed. Further, although the hybrid vehicle 20 of the embodiment outputs the power of the motor MG2 to the axle connected to the ring gear shaft 32a, the application target of the present invention is not limited to this. That is, the present invention is different from the axle (the axle to which the wheels 39a and 39b are connected) that is connected to the ring gear shaft 32a as in the hybrid vehicle 20A as a modified example shown in FIG. The present invention may be applied to the one that outputs to the wheels 39c and 39d in FIG.

  Here, the correspondence between the main elements of the above embodiments and modifications and the main elements of the invention described in the column of means for solving the problems will be described. That is, in the above-described embodiment, the engine 22 includes the EGR valve 143 for recirculating exhaust gas from the exhaust system to the intake system, and the variable valve mechanism 130 that can change the opening / closing timing of the intake valve 131 and the exhaust valve 132. Corresponds to the “internal combustion engine”, the motor MG1 capable of inputting / outputting power corresponds to the “first electric motor”, and transmits the power to the crankshaft 26 of the engine 22, the rotating shaft of the motor MG1, and the wheels 39a, 39b. The power distribution / integration mechanism 30 connected to the three shafts of the ring gear shaft 32a as the axle corresponds to “power distribution / integration means”, and the motor MG2 capable of inputting / outputting power to / from the ring gear shaft 32a and the like is “second electric motor”. The battery 50 capable of exchanging electric power with the motors MG1 and MG2 corresponds to the “power storage means” and performs the process of step S110 in FIG. The hybrid ECU 70 that corresponds to the “required driving force setting means” corresponds to the combination of the hybrid ECU 70, the engine ECU 24, and the motor ECU 40 that executes the accelerator-off-time drive control routine of FIG. The engine ECU 24 that executes the EGR valve abnormality diagnosis routine of FIG. 7 corresponds to “abnormality diagnosis means”.

  However, as long as the “internal combustion engine” has an exhaust gas recirculation valve and a variable valve mechanism, the internal combustion engine is not limited to the engine 22 that outputs power by receiving a hydrocarbon-based fuel such as gasoline or light oil. It may be of any other type such as The “first motor” and the “second motor” are not limited to the synchronous generator motors such as the motors MG1 and MG2, and may be of any other type such as an induction motor. The “power distribution and integration means” is connected to three axes of the engine shaft of the internal combustion engine, the rotation shaft of the first electric motor, and a predetermined axle that transmits power to the drive wheels, and any two of these three shafts As long as it can input and output power based on the power input and output to and from the remaining shaft, it is not limited to the power distribution and integration mechanism 30 that is a single pinion planetary gear mechanism, and other such as a double pinion planetary gear mechanism and a differential gear It may be of any form. The “storage means” is not limited to a secondary battery such as the battery 50, and may be of any other type such as a capacitor as long as it can exchange electric power with an electric motor or power / power input / output means. Absent. The “required driving force setting means” is not limited to the one that sets the required torque as the required driving force based on the accelerator opening and the vehicle speed, but, for example, the one that sets the required driving force based only on the accelerator opening. Any other format may be used. The “accelerator off time control means” is not limited to the combination of the hybrid ECU 70, the engine ECU 24, and the motor ECU 40 that executes the accelerator off time drive control routine of FIG. It may be of any other type such as an electronic control unit. The “abnormality diagnosis means” is not limited to the engine ECU 24 that executes the EGR valve abnormality diagnosis routine of FIG. 7, and may be of any other type as long as the same processing is executed. In any case, the correspondence between the main elements of the embodiments and the modified examples and the main elements of the invention described in the column of means for solving the problems is the same as the means for the embodiments to solve the problems. Since this is an example for specifically explaining the best mode for carrying out the invention described in the column, the elements of the invention described in the column for means for solving the problems are not limited. In other words, the examples are merely specific examples of the invention described in the column of means for solving the problem, and the interpretation of the invention described in the column of means for solving the problem is described in the description of that column. Should be done on the basis.

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

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

It is a schematic block diagram of the hybrid vehicle 20 of an Example. 2 is a schematic configuration diagram of an internal combustion engine device 21. FIG. It is a flowchart which shows an example of the drive control routine at the time of accelerator off performed by hybrid ECU70 of an Example. It is explanatory drawing which shows an example of the map for request torque setting at the time of accelerator off. It is explanatory drawing which shows an example of the map for target rotation speed setting at the time of accelerator off. FIG. 6 is an explanatory diagram illustrating a collinear diagram showing a dynamic relationship between the rotational speed and torque of a rotating element in the power distribution and integration mechanism 30. It is a flowchart which shows an example of the EGR valve abnormality diagnosis routine performed by engine ECU24 of an Example. It is a schematic block diagram of the hybrid vehicle 20A which concerns on a modification.

Explanation of symbols

  20, 20A hybrid vehicle, 21 internal combustion engine device, 22 engine, 24 engine electronic control unit (engine ECU), 24a, 72 CPU, 24b, 74 ROM, 24c, 76 RAM, 26 crankshaft, 28 damper, 30 power distribution Integrated mechanism, 31 sun gear, 32 ring gear, 32a ring gear shaft, 33 pinion gear, 34 carrier, 35 reduction gear, 37 gear mechanism, 38 differential gear, 39a-39d wheels, 40 electronic control unit for motor (motor ECU), 41, 42 Inverter, 43, 44 Rotation position detection sensor, 50 battery, 51 Temperature sensor, 52 Electronic control unit for battery (battery ECU), 54 Power line, 70 Electronic control unit for hybrid (hybrid E) U), 80 ignition switch, 81 shift lever, 82 shift position sensor, 83 accelerator pedal, 84 accelerator pedal position sensor, 85 brake pedal, 86 brake pedal stroke sensor, 87 vehicle speed sensor, 120 combustion chamber, 121 piston, 122 air cleaner, 123 Throttle Valve, 124 Throttle Valve Position Sensor, 125 Throttle Motor, 126 Intake Pipe, 127 Fuel Injection Valve, 128 Spark Plug, 129 Ignition Coil, 130 Variable Valve Mechanism, 131 Intake Valve, 132 Exhaust Valve, 133 Cam Position Sensor, 140 exhaust manifold, 141 purification device, 142 EGR pipe, 143 EGR valve, 144 temperature sensor, 180 crank position sensor , 181 Water temperature sensor, 182 In-cylinder pressure sensor, 183 Air flow meter, 184 Intake air temperature sensor, 185 Intake air pressure sensor, 186 Air-fuel ratio sensor, MG1, MG2 motor.

Claims (6)

An internal combustion engine having an exhaust gas recirculation valve for recirculating exhaust gas from the exhaust system to the intake system, and a variable valve mechanism capable of changing an opening / closing timing of at least one of the intake valve and the exhaust valve;
A first electric motor capable of inputting and outputting power;
Power connected to three axes of the engine shaft of the internal combustion engine, the rotating shaft of the first electric motor, and a predetermined axle for transmitting power to the drive wheels, and power input / output to / from any two of these three shafts Power distribution and integration means for inputting and outputting power based on the remaining shaft;
A second electric motor capable of inputting and outputting power to the axle or another axle different from the axle;
Power storage means capable of exchanging power with the first and second electric motors;
Requested driving force setting means for setting a requested driving force required for traveling according to the driver's accelerator operation;
The motoring of the internal combustion engine by the first electric motor and the internal combustion engine in a state where fuel supply is stopped until a predetermined valve timing change release condition is satisfied when the accelerator operation state by the driver is the accelerator off state Power based on the set required driving force can be obtained with a change in the opening / closing timing of at least one of the intake valve and the exhaust valve by the variable valve mechanism for promoting the intake of gas into the combustion chamber of the engine. In addition to controlling the internal combustion engine and the first and second electric motors, and after the valve timing change cancellation condition is satisfied when the accelerator operation state by the driver is the accelerator off state, the variable valve mechanism In the first electric motor in a state where the fuel supply is stopped without changing the opening / closing timing by An accelerator-off time control unit operable to control the internal combustion engine of motoring said internal combustion engine as the power based on the set required driving force is obtained with the first and second electric motor that,
While the accelerator operation state by the driver is the accelerator off state and the fuel supply to the internal combustion engine is stopped, the change of the opening / closing timing by the variable valve mechanism is caused by at least the establishment of the valve timing change release condition. The exhaust pipe recirculation valve is opened and closed when the predetermined abnormality diagnosis execution condition is satisfied, which includes that a predetermined waiting time has passed since the release, and the fluctuation in the intake pipe pressure due to the opening and closing of the exhaust gas recirculation valve An abnormality diagnosis means for diagnosing the presence or absence of abnormality of the exhaust gas recirculation valve based on the state;
A hybrid car with The hybrid vehicle according to claim 1,
The abnormality diagnosis execution condition is that the cooling water temperature of the internal combustion engine is equal to or higher than a predetermined temperature after the waiting time has elapsed since the change in the opening / closing timing is canceled, and the fuel supply stop time is equal to or longer than a predetermined time. The hybrid vehicle is a condition that includes, as establishment requirements, that the closing time of the exhaust gas recirculation valve is equal to or longer than a predetermined time, and that the degree of change in the rotational speed of the engine shaft and the amount of intake air are equal to or less than a predetermined degree, respectively. . The hybrid vehicle according to claim 1 or 2,
The valve timing change cancellation condition is a hybrid vehicle that is a condition that includes as a requirement that the rotational speed of the engine shaft is less than a predetermined value. The hybrid vehicle according to any one of claims 1 to 3,
The accelerator-off-time control means is configured such that the internal combustion engine is motored by the first electric motor in a state where the fuel supply is stopped when an accelerator operation state by a driver is an accelerator off state, and the engine shaft is A hybrid vehicle that rotates at a target rotational speed determined according to a vehicle speed and controls the internal combustion engine and the first and second electric motors so as to obtain power based on the required driving force. The hybrid vehicle according to any one of claims 1 to 4,
The power distribution and integration means includes a first element connected to the engine shaft of the internal combustion engine, a second element connected to the rotation shaft of the first electric motor, and a third element connected to the predetermined axle. And a hybrid vehicle which is a planetary gear mechanism configured such that these three elements can be differentially rotated with respect to each other. An internal combustion engine having an exhaust gas recirculation valve for recirculating exhaust gas from the exhaust system to the intake system, and a variable valve mechanism capable of changing the opening / closing timing of at least one of the intake valve and the exhaust valve, and power input / output Connected to three shafts of a first motor, an engine shaft of the internal combustion engine, a rotating shaft of the first motor, and a predetermined axle for transmitting power to drive wheels, any two of these three shafts Power distribution integration means for inputting / outputting power based on power input / output to / from the remaining shaft, a second electric motor capable of inputting / outputting power to the axle or another axle different from the axle, and the first And a method for controlling a hybrid vehicle comprising a power storage means capable of exchanging electric power with a second electric motor,
(A) Motoring of the internal combustion engine by the first electric motor in a state where fuel supply is stopped until a predetermined valve timing change release condition is satisfied when the accelerator operation state by the driver is the accelerator off state And the power based on the set required driving force with the change of the opening / closing timing of at least one of the intake valve and the exhaust valve by the variable valve mechanism for promoting the intake of gas into the combustion chamber of the internal combustion engine. The internal combustion engine and the first and second electric motors are controlled so as to be obtained, and after the valve timing change cancellation condition is satisfied when the accelerator operation state by the driver is the accelerator off state, The first electric power in a state where the fuel supply is stopped without changing the opening / closing timing by a variable valve mechanism. And controlling said internal combustion engine and the first and second electric motor as motive power based on the set required driving force is obtained with a motoring of the internal combustion engine by the machine,
(B) While the accelerator operation state by the driver is the accelerator off state and the fuel supply to the internal combustion engine is stopped, the opening / closing timing by the variable valve mechanism is satisfied at least when the valve timing change release condition is satisfied. The exhaust gas recirculation valve is opened and closed and the exhaust pipe recirculation valve is opened and closed when a predetermined abnormality diagnosis execution condition is satisfied, which includes that a predetermined waiting time has passed since the change of Diagnosing the presence or absence of abnormality of the exhaust gas recirculation valve based on the pressure fluctuation state;
Control method of hybrid vehicle including

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