JP2008189267A - Hybrid vehicle and its control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To more securely and properly perform abnormality diagnostic of a cold emission reducing process in a hybrid vehicle. <P>SOLUTION: In a hybrid vehicle 20, a warm up drive control of an engine 22 accompanying the cold emission reducing process for setting a control parameter of the engine 22 is performed so that activation of an emission gas purifying catalyst of a purifying device 134 is promoted until a predetermined catalyst activating condition is satisfied after starting the engine 22 under a predetermined cold condition. Then the abnormality diagnostic (step S300 to S370) for determining existence of abnormality in the cold emission reducing process is executed accompanying these cold emission reducing process, and termination of the warm up drive control of the engine 22 is inhibited while the abnormality diagnostic is being performed (step S320). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a hybrid vehicle having an internal combustion engine and an electric motor each capable of outputting driving power and a control method thereof.

Conventionally, as an internal combustion engine for automobiles, the activity of an exhaust purification catalyst is corrected by correcting a plurality of control parameters such as ignition timing, engine speed (intake amount) or air-fuel ratio (fuel supply amount) during cold start. There is known a method for executing a cold emission reduction strategy that promotes conversion (warm-up) to enhance emission performance (see, for example, Patent Document 1). In this internal combustion engine, an abnormality diagnosis of the cold emission reduction strategy is performed by the control unit. In this abnormality diagnosis, if the integrated value of the fuel injection amount is larger than a predetermined failure determination threshold value, it is determined that there is an abnormality in the cold emission reduction strategy. Conventionally, as a technique for reducing emissions in hybrid vehicles, the amount of air supplied to the internal combustion engine, the amount of fuel, the ignition timing, etc. are set so that the catalyst temperature rises quickly, and the ignition is performed. There is also known a system that compensates for a decrease in the output of an internal combustion engine due to a timing delay or the like with power from a motor or a generator (see, for example, Patent Document 2).
JP 2004-03430 A JP 2006-46341 A

  By the way, the above-mentioned process for reducing cold emissions (“Cold Start Strategy”, hereinafter referred to as “cold emission reduction process”) reduces the emissions associated with the cold start of the internal combustion engine more effectively. In order to achieve this, it is necessary to perform abnormality diagnosis of the cold emission reduction process more appropriately and reliably. In addition to automobiles including only an internal combustion engine as described in Patent Document 1 as a driving source for driving, a hybrid automobile having an internal combustion engine and an electric motor each capable of outputting driving power is reduced. Needless to say, diagnosis of processing abnormality is important. However, each of the above patent documents does not disclose how to perform abnormality diagnosis of cold emission reduction processing in a hybrid vehicle.

  Accordingly, an object of the present invention is to more reliably and appropriately execute an abnormality diagnosis of cold emission reduction processing in a hybrid vehicle.

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

The hybrid vehicle according to the present invention is
An internal combustion engine capable of outputting driving power;
Purification means including a catalyst for purifying exhaust gas discharged from the internal combustion engine;
An electric motor capable of outputting driving power;
Power storage means capable of exchanging power with the motor;
Cold emission reduction for setting control parameters of the internal combustion engine so that activation of the catalyst is promoted until a predetermined catalyst activation condition is satisfied after the internal combustion engine is started under a predetermined cold state Cold engine control means for performing warm-up operation control of the internal combustion engine with processing;
Diagnosing means for executing an abnormality diagnosis for determining whether there is an abnormality in the cold emission reduction process;
While the abnormality diagnosis is being executed by the diagnosis means, warm-up end prohibiting means for prohibiting the end of the warm-up operation control;
Is provided.

  In this hybrid vehicle, the internal combustion engine control parameters are set so that the activation of the catalyst is promoted until the predetermined catalyst activation condition is satisfied after the internal combustion engine is started under a predetermined cold state. Warm-up operation control of the internal combustion engine accompanied by emission reduction processing is executed. In this hybrid vehicle, along with such a cold emission reduction process, an abnormality diagnosis for determining whether there is an abnormality in the cold emission reduction process is performed, and while the abnormality diagnosis is being performed, the warm-up operation is performed. Termination of control is prohibited. As a result, the warm-up operation control of the internal combustion engine is basically continued until the abnormality diagnosis of the cold emission reduction process is completed. The abnormality diagnosis can be executed more properly while the engine is warming up.

  The warm-up end prohibiting unit may prohibit the end of the warm-up operation control when the abnormality diagnosis by the diagnostic unit is not completed even if the catalyst activation condition is satisfied. . As a result, it is possible to more reliably secure an opportunity for executing an abnormality diagnosis of the cold emission reduction process.

  Furthermore, the warm-up operation control may control the internal combustion engine so that the internal combustion engine is independently operated at a predetermined independent rotation speed.

  The hybrid vehicle includes the internal combustion engine when the required driving force setting means for setting the required driving force required for traveling and the warm-up operation control prohibition by the warm-up completion prohibiting means are prohibited. May further include drive control means capable of controlling the internal combustion engine and the electric motor so that power can be obtained based on the set required driving force while being independently operated at the independent rotation speed. That is, in a hybrid vehicle, even if the internal combustion engine is independently operated at the independent rotation speed and substantially does not output the driving power, the electric motor is operated by the electric power from the power storage means to obtain the driving power. be able to. Therefore, in this hybrid vehicle, even when the abnormality diagnosis is executed and the end of the warm-up operation control of the internal combustion engine is prohibited, it is possible to travel with power based on the required driving force required for traveling. Become.

  The abnormality diagnosis may be a process of determining whether or not there is an abnormality in the cold emission reduction process based on an integrated value of fuel supplied to the internal combustion engine after the internal combustion engine is started. As a result, it is possible to accurately determine whether there is an abnormality in the cold emission reduction process.

  Further, the hybrid vehicle is connected to an engine shaft and an axle of the internal combustion engine and inputs / outputs power to / from the engine shaft and the axle with input / output of electric power and power, and supplies power to the power storage means. You may further provide the electric power drive input / output means which can communicate. The power drive input / output means is connected to three shafts of a generator motor capable of inputting / outputting power, the axle, the engine shaft of the internal combustion engine, and a rotation shaft of the generator motor. 3 axis type power input / output means for inputting / outputting power based on the power input / output to / from any of the two axes to / from the remaining shafts.

The hybrid vehicle control method according to the present invention includes:
An internal combustion engine capable of outputting traveling power, a purification means including a catalyst for purifying exhaust gas discharged from the internal combustion engine, an electric motor capable of outputting traveling power, and electric power exchangeable with the electric motor And a control parameter of the internal combustion engine is set so that activation of the catalyst is promoted until a predetermined catalyst activation condition is satisfied after the internal combustion engine is started in a predetermined cold state. A control method for a hybrid vehicle comprising a cold engine control means for executing warm-up operation control of the internal combustion engine with cold emission reduction processing,
The method includes a step of executing an abnormality diagnosis for determining whether or not there is an abnormality in the cold emission reduction process while prohibiting the end of the warm-up operation control.

  According to this method, since the warm-up operation control of the internal combustion engine is basically continued until the abnormality diagnosis of the cold emission reduction process is completed, the opportunity for executing the abnormality diagnosis is more reliably secured. Abnormality diagnosis can be more appropriately executed in a state where the internal combustion engine is warmed up.

  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. The hybrid vehicle 20 shown in FIG. 1 includes an engine 22, a three-shaft power distribution and integration mechanism 30 connected to a crankshaft 26 that is an output shaft of the engine 22 via a damper (not shown), and a power distribution and integration mechanism 30. A hybrid electronic control unit (hereinafter referred to as a “hybrid ECU”) that controls the motor MG1 that can generate power, the motor MG2 that is connected to the power distribution and integration mechanism 30 via the transmission 60, and the hybrid vehicle 20 as a whole. 70).

The engine 22 is configured as an internal combustion engine that outputs power by receiving supply of hydrocarbon fuel such as gasoline or light oil. In the engine 22, as can be seen from FIG. 2, the air purified by the air cleaner 122 is taken into the intake port via the throttle valve 124, and fuel such as gasoline is injected from the fuel injection valve 126 into the intake air. The air / fuel mixture thus obtained is sucked into the combustion chamber via the intake valve 128 and explosively burned by electric sparks from the spark plug 130. Then, the reciprocating motion of the piston 132 accompanying the explosion combustion of the air-fuel mixture is converted into the rotational motion of the crankshaft 26. Exhaust gas from the engine 22 passes through a purification device 134 having an exhaust gas purification catalyst (three-way catalyst) that purifies harmful components such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx). It is discharged outside. The exhaust gas purifying catalyst of the purifying device 134 may be composed of an oxidation catalyst such as platinum (Pt) or palladium (Pd), a reduction catalyst such as rhodium (Rh), a promoter such as ceria (CeO ₂ ), or the like. . In this case, CO and HC contained in the exhaust gas are purified to water (H ₂ O) and carbon dioxide (CO ₂ ) by the action of the oxidation catalyst, and NOx contained in the exhaust gas is nitrogen (N ₂ ) and Purified to oxygen (O ₂ ). The engine 22 of the embodiment includes an EGR pipe 152 that is connected to the rear stage of the purification device 134 and supplies exhaust gas to the intake side. As a result, exhaust gas as non-combustion gas can be supplied to the intake side, and a mixture of air, fuel and exhaust gas can be sucked into the combustion chamber. For the EGR pipe 152, an EGR valve 154 for adjusting the supply amount (EGR amount) of exhaust gas (EGR gas) supplied to the intake side, and the temperature of the EGR gas in the EGR pipe 152 are detected. A temperature sensor 156 or the like is attached.

  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 a timing command A timer 24d that executes time-measurement processing in response to the input / output port and communication port (not shown) is included. 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 is arranged with respect to the crank position from the crank position sensor 140 that detects the rotational position of the crankshaft 26, the coolant temperature from the water temperature sensor 142 that detects the coolant temperature of the engine 22, and the combustion chamber. The in-cylinder pressure from the pressure sensor 143, the cam position from the cam position sensor 144 that detects the rotational position of the intake valve 128 that performs intake and exhaust to the combustion chamber and the camshaft that opens and closes the exhaust valve 129, and the position of the throttle valve 124 The throttle position from the throttle valve position sensor 146 for detecting the intake air amount, the intake air amount from the air flow meter 148 for detecting the intake air amount as a load of the engine 22, the intake air temperature from the temperature sensor 149 attached to the intake pipe, the EGR pipe Attached to 152 EGR gas temperature from a temperature sensor 156 is input via the input port. Further, the engine ECU 24 controls the exhaust gas of the purifier 134 based on the intake air amount GA from the air flow meter 148, the cooling water temperature from the water temperature sensor 142, the air-fuel ratio from an A / F sensor (not shown), the retard amount of the ignition timing, and the like. The temperature of the purification catalyst (catalyst bed temperature) is estimated. 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 126, the drive signal to the throttle motor 136 that adjusts the position of the throttle valve 124, the control signal to the ignition coil 138 integrated with the igniter, and the opening and closing of the intake valve 128. A control signal to the variable valve timing mechanism 150 whose timing can be changed, a drive signal to the EGR valve 154, 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, for example, an external gear sun gear 30a, an internal gear ring gear 30b disposed concentrically with the sun gear 30a, a plurality of pinion gears 30c that mesh with the sun gear 30a and mesh with the ring gear 30b. A planetary gear mechanism is provided that includes a carrier 30d that holds a plurality of pinion gears 30c so as to rotate and revolve, and that performs differential action using the sun gear 30a, the ring gear 30b, and the carrier 30d as rotating elements. In this case, the crankshaft of the engine 22 is connected to the carrier 30d of the power distribution and integration mechanism 30, the motor MG1 is connected to the sun gear 30a, and the ring gear 30b is connected to the motor MG2 via a ring gear shaft 32 as a rotatable axle. Transmissions 60 are connected to each other. The power distribution and integration mechanism 30 distributes the power from the engine 22 input from the carrier 30d to the sun gear 30a side and the ring gear 30b side according to the gear ratio when the motor MG1 functions as a generator, and the motor MG1 is an electric motor. , The power from the engine 22 input from the carrier 30d and the power from the motor MG1 input from the sun gear 30a are integrated and output to the ring gear 30b side. The power output to the ring gear 30 b is output to the wheels 34 a and 34 b as drive wheels via the differential gear 33.

  The motor MG1 and the motor MG2 are both configured as well-known synchronous generator motors that operate as generators and can operate as motors, and exchange power with the battery 50 via inverters 41 and 42. The power line connecting the inverters 41 and 42 and the battery 50 is configured as a positive bus and a negative bus shared by the respective 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 a 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 includes signals necessary for driving and controlling the motors MG1 and MG2, such as a signal from a rotational position detection sensor (not shown) for detecting the rotational position of the rotor of the motors MG1 and MG2, and a current sensor (not shown). The phase current applied to the motors MG1 and MG2 detected by the motor, motor temperatures T1 and T2 from temperature sensors (not shown) provided for the motors MG1 and MG2, respectively, are input. Switching control signals to 41 and 42 are output. Further, the motor ECU 40 communicates with the hybrid ECU 70, controls the driving of the motors MG1, MG2 based on a 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 is attached to a signal 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 connected to the output terminal of the battery 50. The charge / discharge current from the current sensor, the battery temperature from a temperature sensor (not shown) 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, 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 transmission 60 performs connection between the rotating shaft 31 of the motor MG2 and the ring gear shaft 32 and release of the connection, and a gear ratio between the two shafts (the rotation shaft 31 of the rotating shaft 31) when the rotating shaft 31 and the ring gear shaft 32 are connected. The number of rotations / the number of rotations of the ring gear shaft 32: the reduction ratio as viewed from the motor MG2 can be set in a plurality of stages. In the embodiment, the transmission 60 includes a double pinion planetary gear mechanism (not shown), a single pinion planetary gear mechanism, and two brakes B1 and B2 driven by a hydraulic actuator, and the rotation of the motor MG2. The rotational speed of the shaft 31 can be reduced to two stages and transmitted to the ring gear shaft 32. Thus, the power from the motor MG2 is basically decelerated by the transmission 60 and input to the ring gear shaft 32, and the power from the ring gear shaft 32 is accelerated by the transmission 60 and input to the motor MG2. Become. The transmission 60 is not limited to one having two speeds, and may be a stepped transmission having three or more speeds, or a simple speed reducer, and is omitted by itself. May be.

  The hybrid ECU 70 is configured as a microprocessor centered on the CPU 72. In addition to the CPU 72, the hybrid ECU 70 includes a ROM 74 that stores various processing programs, a RAM 76 that temporarily stores data, an input / output port and a communication port (not shown). Prepare. The hybrid ECU 70 includes a shift position SP from a shift position sensor 82 for detecting an ignition signal from an ignition switch (start switch) 80, an operation position (shift position) of the shift lever 81 such as a parking position and a forward driving D position, Accelerator opening degree Acc from the accelerator pedal position sensor 84 that detects the amount of depression of the accelerator pedal 83, brake pedal position BP from the brake pedal position sensor 86 that detects the amount of depression of the brake pedal 85, vehicle speed V from the vehicle speed sensor 87, etc. Is input through 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 configured as described above, a request to be output to the ring gear shaft 32 as the drive shaft based on the accelerator opening Acc and the vehicle speed V corresponding to the depression amount of the accelerator pedal 83 by the driver. Torque Tr * is calculated, and operation of engine 22, motor MG1, and motor MG2 is controlled so that power corresponding to this required torque Tr * is output to ring gear shaft 32. As the operation control mode of the engine 22, the motor MG1, and the motor MG2, the engine 22 is operated and 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 a power distribution integration mechanism. 30, the torque conversion operation mode for driving and controlling the motor MG 1 and the motor MG 2 so that the torque is converted by the motor MG 1 and the motor MG 2 and output to the ring gear shaft 32, the required power and the power required for charging and discharging the battery 50. The engine 22 is operated and controlled so that the power corresponding to the sum is output from the engine 22, and all or a part of the power output from the engine 22 with charge / discharge of the battery 50 is the power distribution integration mechanism 30 and the motor MG1. And the required power is ring gear with torque conversion by motor MG2 A charge / discharge operation mode in which the motor MG1 and the motor MG2 are controlled to be output to the motor 32, and a motor operation in which the operation of the engine 22 is stopped and the motor MG2 is controlled to output power corresponding to the required power to the ring gear shaft 32. There are modes.

  By the way, in the hybrid vehicle 20 of the embodiment as well, it is necessary to reduce the emission when the engine 22 is started in the cold as in the case of the vehicle including only the engine as the driving source for traveling. When the engine 22 is started under a predetermined cold state in which the SOC is within a predetermined range and the coolant temperature or the catalyst bed temperature detected or estimated when the engine 22 is requested to start is below a predetermined threshold value, respectively. The engine is activated so that activation of the exhaust gas purification catalyst of the purification device 134 is promoted until a predetermined catalyst activation condition is satisfied after the engine is started (for example, until the catalyst bed temperature becomes equal to or higher than the predetermined activation temperature). The hybrid ECU 70 controls the warm-up operation of the engine 22 accompanied by the cold emission reduction process for setting the control parameter 22. It is performed by the original engine ECU24 of the directive. In the embodiment, the cold emission reduction process by the engine ECU 24 is, for example, correcting the ignition timing based on the cooling water temperature from the water temperature sensor 142, or correcting the engine speed and the air-fuel ratio. . In the warm-up operation control, the engine 22 is autonomously operated so that substantially no torque is output at a self-sustaining rotational speed Ni (for example, 1100 to 1400 rpm) slightly higher than the rotational speed at the time of normal idling. . And in order to reduce the emission accompanying the cold start of the engine 22 more effectively, it is necessary to determine whether there is an abnormality in the cold emission reduction process. Therefore, in the hybrid vehicle 20 of the embodiment, the CSS abnormality diagnosis routine shown in FIG. 3 is executed by the engine ECU 24.

  Next, the CSS abnormality diagnosis routine will be described with reference to FIG. In the CSS abnormality diagnosis routine of FIG. 3, there is no abnormality in a predetermined sensor related to the engine 22 after the engine 22 warm-up operation control accompanied by a cold emission reduction process by the engine ECU 24 is started after the engine 22 is started. (Substantially after a predetermined time has elapsed since the start of the cold emission reduction process). At the start of the CSS abnormality diagnosis routine of FIG. 3, the CPU 24a of the engine ECU 24 sets an elapsed time t (elapsed time after E / G start) counted by the timer 24d and a warm-up forced end flag Fws. Data necessary for abnormality diagnosis, such as a value and an injection valve energization time ti, which is an energization time of the injector coil of the fuel injection valve 126, is input (step S300). Note that the warm-up forced end flag Fws is set by the hybrid ECU 70 based on the remaining capacity SOC or the like from the battery ECU 52, and is input by communication. For example, the remaining charge SOC from the battery ECU 52 is less than a predetermined lower limit value or exceeds a predetermined upper limit value, and the hybrid ECU 70 performs warm-up operation (cold emission reduction processing) of the engine 22 from the viewpoint of component protection. If it is not desirable to continue, the warm-up forced end flag Fws is set to a value of 1. Otherwise, the warm-up forced end flag Fws is set to a value of 0.

  After the data input process of step S300, it is determined whether or not the input warm-up forced end flag Fws is 0 (step S310). The warm-up forced end flag Fws is 0 and the engine 22 is warmed up. If the continuation of operation is permitted, a predetermined diagnosis execution flag Fcssd is set to 1 (step S320). The diagnosis execution flag Fcssd is set to a value of 1 when the routine, that is, the abnormality diagnosis of the cold emission reduction process by the engine ECU 24 is being executed. The diagnosis execution flag Fcssd is set to a value of 1. When the engine is on, the end of the warm-up operation control of the engine 22 is prohibited. Next, based on the injection valve energization time ti input in step S300, an integrated fuel injection amount Ft, which is an integrated value of the fuel injection amount after the engine 22 is started, is calculated (step S330). Subsequently, it is determined whether or not the elapsed time t input in step S300 is equal to or longer than a predetermined threshold value tref (for example, several seconds) (step S340). The processing after S300 is executed. When it is determined in step S340 that the elapsed time t is equal to or greater than the threshold value tref, it is determined whether or not the integrated fuel injection amount Ft calculated in step S330 is equal to or greater than a predetermined threshold value Fref. (Step S350). That is, the degree of emission reduction is closely related to the integrated fuel injection amount Ft after the engine 22 is started. If the integrated fuel injection amount Ft after the engine 22 is started is sufficiently secured, It can be considered that the emission reduction processing is executed without any abnormality. Therefore, if it is determined in step S350 that the integrated fuel injection amount Ft is equal to or greater than the threshold value Fref, the CSS abnormality flag is set to 0 to indicate that the cold emission reduction processing is being executed normally. (Step S360) Further, the diagnosis execution flag Fcssd is set to 0 (step S380), and then this routine is terminated. In contrast, if it is determined in step S350 that the integrated fuel injection amount Ft is less than the threshold value Fref, the CSS abnormality flag is set to a value 1 to indicate that there is some abnormality in the cold emission reduction processing. (Step S370), the diagnosis execution flag Fcssd is further set to 0 (Step S380), and this routine is terminated. Note that the threshold value Fref used in step S350 is determined based on the fact that the cold emission reduction process corrects the ignition timing and the like mainly based on the cooling water temperature detected by the water temperature sensor 142 as described above. It may be set based on the cooling water temperature at the time, or may be a constant value to simplify the control logic. When the CSS abnormality flag is set to 1 in step S370, a predetermined warning lamp provided on an instrument panel (not shown) is turned on.

  On the other hand, if it is determined in step S310 that the warm-up forced end flag Fws is 1 and the continuation of the warm-up operation of the engine 22 is not permitted, the diagnosis execution flag Fcssd is set to 0. (Step S380), this routine is terminated. Thereby, in the hybrid vehicle 20 of the embodiment, the warm-up operation of the engine 22 with the cold emission reduction process is performed except when the warm-up forced end flag Fws is set to the value 1 according to the state of the battery 50. Once the control is started, the end of the warm-up operation control of the engine 22 is prohibited until the CSS abnormality diagnosis routine of FIG. 3, that is, the abnormality diagnosis of the cold emission reduction process is completed. As a result, the abnormality diagnosis can be more appropriately executed while the engine 22 is warming up.

  Here, the shift lever 81 is set to the parking position while the above-described warm-up operation control of the engine 22 accompanied with the cold emission reduction process and the accompanying abnormality diagnosis of the cold emission reduction process are executed. For example, since it is not necessary to output traveling torque (including creep torque) to the ring gear shaft 32 as an axle, the warm-up operation control of the engine 22 is terminated until the abnormality diagnosis of the cold emission reduction process is completed. There is no problem even if prohibited. However, after the warm-up operation control of the engine 22 accompanied by the cold emission reduction process is started, before the abnormality diagnosis of the cold emission reduction process is completed, the shift lever 81 is set to the D position by the driver. In this case, it is necessary to output traveling torque (including creep torque) to the ring gear shaft 32 as an axle.

  Therefore, with reference to FIG. 4 again, the hybrid vehicle 20 when the shift lever 81 is set to the forward drive D position after the warm-up operation control of the engine 22 accompanied by the cold emission reduction process is started. Will be described. FIG. 4 shows that when the shift lever 81 is set to the forward driving D position after the warm-up operation control of the engine 22 accompanied by the cold emission reduction process is started, the hybrid ECU 70 performs the predetermined time intervals (for example, It is a flowchart which shows an example of the drive control routine after an engine starting performed every several milliseconds).

  At the start of the drive control routine after engine start in FIG. 4, the CPU 72 of the hybrid ECU 70 determines the accelerator opening Acc from the accelerator pedal position sensor 84, the vehicle speed V from the vehicle speed sensor 87, the gear ratio Gr of the transmission 60, the motor MG1, and the like. MG2 rotation speeds Nm1, Nm2, charge / discharge required power Pb *, input / output limits Win and Wout which are power allowed for charging / discharging of the battery 50, and the value of the diagnosis execution flag Fcssd are input. Execute (Step S100). Here, the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 are input from the motor ECU 40 by communication. The gear ratio Gr of the transmission 60 is set when a shift of the transmission 60 is executed by a shift processing routine (not shown) and is stored in a predetermined area of the RAM 76. Further, the charge / discharge required power Pb * is input from the battery ECU 52 by communication from the battery ECU 52 as power to be charged / discharged by the battery ECU 52 based on the remaining capacity SOC of the battery 50 or the like. Similarly, the input / output limits Win and Wout of the battery 50 are set based on the temperature Tb of the battery 50 and the remaining capacity SOC of the battery 50 and are input from the battery ECU 52 by communication. The value of the diagnosis execution flag Fcssd is input from the engine ECU 24 by communication.

  After the data input process in step S100, the required torque Tr to be output to the ring gear shaft 32 as the axle connected to the wheels 34a and 34b as drive wheels based on the accelerator opening Acc and the vehicle speed V input in step S100. After setting *, the required power P * required for the entire vehicle is set (step S110). In the embodiment, the relationship among the accelerator opening Acc, the vehicle speed V, and the required torque Tr * is determined in advance and stored in the ROM 74 as a required torque setting map. The required torque Tr * is the given accelerator opening. The one corresponding to Acc and the vehicle speed V is derived and set from the map. FIG. 5 shows an example of the required torque setting map. In the embodiment, the required power P * is calculated as the sum of the set required torque Tr * multiplied by the rotation speed Nr of the ring gear shaft 32, the charge / discharge required power Pb *, and the loss Loss. The rotational speed Nr of the ring gear shaft 32 can be obtained by dividing the rotational speed Nm2 of the motor MG2 by the gear ratio Gr of the transmission 60 as shown in the figure or by multiplying the vehicle speed V by the conversion factor k.

  Next, it is determined whether or not the diagnosis execution flag Fcssd input in step S100 is a value 1 (step S120). If the diagnosis execution flag Fcssd is a value 1, the engine 22 is operated at the above-described independent rotation speed Ni. As described above, the target rotational speed Ne * of the engine 22 is set to the value Ni, the target torque Te * is set to the value 0 (step S130), and the torque command Tm1 * for the motor MG1 is further set to the value 0 (step). S140). Subsequently, the deviation between the input / output limits Win and Wout of the battery 50 input in step S100 and the power consumption of the motor MG1 obtained as the product of the torque command Tm1 * and the current rotational speed Nm1 of the motor MG1 is calculated as the motor MG2. The torque limits Tmin and Tmax as upper and lower limits of the torque that may be output from the motor MG2 by dividing by the rotation speed Nm2 are calculated using the following equations (1) and (2) (step S150). Based on the required torque Tr * and the gear ratio Gr of the transmission 60, a temporary motor torque Tm2tmp as a torque to be output from the motor MG2 is calculated according to the following equation (3) (step S160), and a torque command for the motor MG2 is calculated. Tm2 * is set as a value obtained by limiting the temporary motor torque Tm2tmp with the torque limits Tmin and Tmax calculated in step S150 (step S170). By setting the torque command Tm2 * of the motor MG2 in this manner, the torque output to the ring gear shaft 32 as the axle can be set as a torque limited within the range of the input / output limits Win and Wout of the battery 50. . If the target rotational speed Ne * and target torque Te * of the engine 22 and the torque commands Tm1 * and Tm2 * of the motors MG1 and MG2 are thus set, the target rotational speed Ne * and the target torque Te * of the engine 22 are sent to the engine ECU 24. Then, torque commands Tm1 * and Tm2 * of the motors MG1 and MG2 are transmitted to the motor ECU 40 (step S180), and the processes after step S100 are executed again.

  The engine ECU 24 that has received the target rotational speed Ne * and the target torque Te * executes control for obtaining the target rotational speed Ne * and the target torque Te *, that is, in this case, warm-up operation control of the engine 24 is executed. To do. In addition, the motor ECU 40 that has received the torque commands Tm1 * and Tm2 * drives the motors MG1 using the torque commands Tm1 * and the inverters 41 and 42 so that the motor MG2 is driven using the torque commands Tm2 *. Switching control of the switching element is performed. Thereby, in the hybrid vehicle 20, when the end of the warm-up operation control of the engine 22 is prohibited due to the abnormality diagnosis of the cold emission reduction process being executed, that is, the engine 22 is in the independent rotation speed Ni. Even when the vehicle is autonomously operated and does not substantially output the traveling torque, it is possible to travel with power based on the required torque Tr *. When it is determined in step S120 that the diagnosis execution flag Fcssd is 0, this routine is terminated, and a normal drive control routine for outputting the required power P * to the engine 22 is executed.

Tmin = (Win-Tm1 * ・ Nm1) / Nm2 (1)
Tmax = (Wout-Tm1 * ・ Nm1) / Nm2 (2)
Tm2tmp = Tr * / Gr (3)

  As described above, in the hybrid vehicle 20 of the embodiment, the exhaust gas purification catalyst of the purification device 134 is activated until the predetermined catalyst activation condition is satisfied after the engine 22 is started in a predetermined cold state. Warm-up operation control of the engine 22 accompanied by cold emission reduction processing for setting the control parameters of the engine 22 to be promoted is executed. And in this hybrid vehicle 20, the abnormality diagnosis (FIG. 3) for determining the presence or absence of abnormality of a cold emission reduction process is performed with this cold emission reduction process, and the said abnormality diagnosis is performed During this time, the end of the warm-up operation control of the engine 22 is prohibited (step S320). Thus, until the abnormality diagnosis of the cold emission reduction process is completed, the warm-up operation control of the engine 22 is continued except when the warm-up forced end flag Fws is set to 1 according to the state of the battery 50. As a result, it is possible to more reliably ensure the opportunity for executing the abnormality diagnosis and more appropriately execute the abnormality diagnosis in a state where the engine 22 is warmed up. As a result, in the hybrid vehicle 20, it is possible to improve the rate monitor that is the ratio of the number of executions of the abnormality diagnosis of the cold emission reduction process to the actual number of travel opportunities.

  Further, in the hybrid vehicle 20 of the embodiment, if the diagnosis execution flag Fcssd is set to a value 1, the end of the warm-up operation control of the engine 22 is prohibited, so that the catalyst bed temperature is a predetermined activation temperature. If the abnormality diagnosis of the cold emission reduction process is not completed even if the catalyst activation conditions such as described above are satisfied, the end of the warm-up operation control of the engine 22 is prohibited. As a result, it is possible to more reliably secure an opportunity for executing an abnormality diagnosis of the cold emission reduction process. Furthermore, in the hybrid vehicle 20 of the embodiment, when the shift lever 81 is set to the D position for forward travel after the warm-up operation control of the engine 22 accompanied by the cold emission reduction process is started, the engine of FIG. A drive control routine is executed after the start, and the motor MG2 is operated by the electric power from the battery 50 even when the engine 22 is independently operated at the independent rotation speed Ni and substantially does not output the driving power. The power of can be obtained. Therefore, in the hybrid vehicle 20, the abnormality diagnosis of the cold emission reduction process is executed, and the required torque Tr * required for traveling is set even when the end of the warm-up operation control of the engine 22 is prohibited. The driving | running | working by the power based on becomes possible. Then, as in the above embodiment, if it is determined whether there is an abnormality in the cold emission reduction process based on the integrated fuel injection amount Ft that is an integrated value of the fuel supplied to the engine 22 after the engine 22 is started, It is possible to accurately determine whether there is an abnormality in the inter-emission reduction process. However, the abnormality diagnosis of the cold emission reduction process may be a process based on parameters other than the integrated fuel injection amount Ft.

  In addition, although the hybrid vehicle 20 of the said Example outputs the motive power of motor MG2 to the axle connected to the ring gear shaft 32, the application object of this invention is not restricted 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 32 by the power of the motor MG2 as in the hybrid vehicle 20A as a modified example shown in FIG. The present invention may be applied to an output to an axle connected to the wheels 39c and 39d in FIG. The hybrid vehicle 20 of the above embodiment outputs the power of the engine 22 to the ring gear shaft 32 as an axle connected to the wheels 34a and 34b via the power distribution and integration mechanism 30. The subject is not limited to this. That is, the present invention provides an inner rotor 232 connected to the crankshaft of the engine 22 and an outer rotor connected to an axle that outputs power to the wheels 39a and 39b, like a hybrid vehicle 20B as a modification shown in FIG. 234, and may be applied to a motor including a counter-rotor motor 230 that transmits a part of the power of the engine 22 to the axle and converts the remaining power into electric power. Further, the present invention may be applied to a vehicle provided with a continuously variable transmission (hereinafter referred to as “CVT”) as power transmission means for transmitting the power of the engine 22 to the axle side instead of the power distribution and integration mechanism 30. . A hybrid vehicle 20C as an example of such a vehicle is shown in FIG. The hybrid vehicle 20C of the modification shown in the figure is synchronized with a front wheel drive system that outputs power from the engine 22 to, for example, wheels 39a and 39b that are front wheels via a belt-type or toroidal-type CVT 200, a differential gear 38, and the like. And a rear wheel drive system that outputs power from a motor MG that is a generator motor to, for example, wheels 39c and 39d that are rear wheels via a differential gear 38 'or the like. The motor MG is connected to an alternator 29 driven by the engine 22 via an inverter and a battery 50 whose output terminal is connected to the power line from the alternator 29. Thereby, the motor MG is driven by the electric power from the alternator 29 and the battery 50, or charges the battery 50 with the electric power generated by regeneration.

  Here, the correspondence between the main elements of the above embodiment and the main elements of the invention described in the column of means for solving the problems will be described. That is, in the above embodiment, the engine 22 corresponds to the “internal combustion engine”, the purification device 134 including the exhaust gas purification catalyst corresponds to the “purification means”, the motor MG or MG2 corresponds to the “electric motor”, and the motor MG or The battery 50 capable of exchanging electric power with the MG 2 corresponds to “electric storage means”, and after the engine 22 is started in a predetermined cold state until the predetermined catalyst activation condition is satisfied, the exhaust gas purification catalyst of the purification device 134 The engine ECU 24 (and the hybrid ECU 70) that performs the warm-up operation control of the engine 22 with the cold emission reduction process for setting the control parameters of the engine 22 so that the activation of the engine 22 is promoted is “the engine control means during the cold state” The engine ECU 24 that executes the CSS abnormality diagnosis routine of FIG. It corresponds to the stage. " The hybrid ECU 70 that executes step S120 of the drive control routine after engine start in FIG. 4 corresponds to “required drive force setting means”, and the hybrid ECU 70, engine ECU 24, and motor that execute the drive control routine after engine start in FIG. The ECU 40 corresponds to “drive control means”. Further, the power distribution and integration mechanism 30 connected to the crankshaft 26 of the engine 22 and the ring gear shaft 32 as the axle and the motor MG1 correspond to “power power input / output means”, and the motor MG1 becomes the “motor for power generation”. The power distribution and integration mechanism 30 corresponds to “three-axis power input / output means”.

  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, and may be of any other type such as a hydrogen engine. The “purifying means” may be of any type as long as it includes a catalyst for purifying exhaust gas discharged from the internal combustion engine. The “motor” is not limited to the synchronous generator motor such as the motors MG and MG2, but may be any other type such as an induction motor. The “storage means” is not limited to the secondary battery such as the battery 50, and may be any other type such as a capacitor as long as it can exchange electric power with the motor. The “cold engine control means” is a control parameter of the internal combustion engine so that the activation of the catalyst is promoted until a predetermined catalyst activation condition is satisfied after the internal combustion engine is started under a predetermined cold state. Any type other than the engine ECU 24 may be used as long as it performs warm-up operation control of the internal combustion engine with cold emission reduction processing for setting The “diagnostic means” and “warm-up termination prohibiting means” may be any type other than the engine ECU 24 that executes the CSS abnormality diagnosis routine of FIG. 3 as long as it can determine whether or not there is an abnormality in the cold emission reduction process. It doesn't matter. The “required driving force setting means” is not limited to the one that sets the required torque Tr * based on the accelerator opening Acc and the vehicle speed V. Any other type such as one that sets the required torque based only on the degree Acc or the traveling position of the vehicle may be used. The “drive control means” connects the internal combustion engine and the electric motor so that the internal combustion engine can be independently operated at the independent rotation speed and power based on the required driving force can be obtained when the end of the warm-up operation control is prohibited. As long as it can be controlled, it is not limited to the combination of the hybrid ECU 70, the engine ECU 24, and the motor ECU 40, and may be any other type such as a single electronic control unit. The “power / power input / output means” is not limited to the combination of the motor MG1 and the power distribution / integration mechanism 30, but is connected to the engine shaft and the axle of the internal combustion engine, and inputs / outputs power and power to the engine shaft and the axle. Any other type of motor such as a counter-rotor motor 230 that inputs and outputs power may be used.

  In any case, the correspondence between the main elements of the embodiments and the main elements of the invention described in the column of means for solving the problem is described in the column of means for the embodiment to solve the problem. This is an example for specifically describing the best mode for carrying out the invention, and does not limit the elements of the invention described in the column of means for solving the problem. 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.

1 is a schematic configuration diagram of a hybrid vehicle 20 according to an embodiment of the present invention. 2 is a schematic configuration diagram of an engine 22. FIG. It is a flowchart which shows an example of the CSS abnormality diagnosis routine performed by engine ECU24 of an Example. It is a flowchart which shows an example of the drive control routine after engine starting performed by hybrid ECU70 of an Example. It is explanatory drawing which shows an example of the map for request | requirement torque setting. It is a schematic block diagram of the hybrid vehicle 20A which concerns on a modification. FIG. 12 is a schematic configuration diagram of a hybrid vehicle 20B according to another modification. It is a schematic block diagram of the hybrid vehicle 20C which concerns on another modification.

Explanation of symbols

  20, 20A, 20B, 20C Hybrid vehicle, 22 engine, 24 engine electronic control unit (engine ECU), 24a, 72 CPU, 24b, 74 ROM, 24c, 76 RAM, 24d timer, 26 crankshaft, 29 alternator, 30 Power distribution integration mechanism, 30a Sun gear, 30b Ring gear, 30c Pinion gear, 30d Carrier, 31 Rotating shaft, 32 Ring gear shaft, 33, 38, 38 'Differential gear, 34a, 34b, 39a, 39b, 39c, 39d Wheel, 40 For motor Electronic control unit (motor ECU), 41, 42 Inverter, 50 battery, 52 Electronic control unit for battery (battery ECU), 60 Transmission, 70 Electronic control unit for hybrid (hybrid CU), 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, 87 vehicle speed sensor, 122 air cleaner, 124 throttle valve, 126 fuel injection Valve, 128 Intake valve, 129 Exhaust valve, 130 Spark plug, 132 Piston, 134 Purifier, 136 Throttle motor, 138 Ignition coil, 140 Crank position sensor, 142 Water temperature sensor, 143 Pressure sensor, 144 Cam position sensor, 146 Throttle valve Position sensor, 148 Air flow meter, 149 Temperature sensor, 150 Variable valve timing mechanism, 152 EG R pipe, 154 EGR valve, 156 Temperature sensor, 200 CVT, 230 Counter rotor motor, 232 Inner rotor, 234 Outer rotor, MG1, MG2 motor.

Claims (8)

An internal combustion engine capable of outputting driving power;
Purification means including a catalyst for purifying exhaust gas discharged from the internal combustion engine;
An electric motor capable of outputting driving power;
Power storage means capable of exchanging power with the motor;
Cold emission reduction for setting control parameters of the internal combustion engine so that activation of the catalyst is promoted until a predetermined catalyst activation condition is satisfied after the internal combustion engine is started under a predetermined cold state Cold engine control means for performing warm-up operation control of the internal combustion engine with processing;
Diagnosing means for executing an abnormality diagnosis for determining whether there is an abnormality in the cold emission reduction process;
While the abnormality diagnosis is being executed by the diagnosis means, warm-up end prohibiting means for prohibiting the end of the warm-up operation control;
A hybrid car with   2. The hybrid vehicle according to claim 1, wherein the warm-up termination prohibiting unit prohibits termination of the warm-up operation control when the abnormality diagnosis by the diagnostic unit is not completed even when the catalyst activation condition is satisfied. .   The hybrid vehicle according to claim 1, wherein the warm-up operation control is to control the internal combustion engine so that the internal combustion engine is independently operated at a predetermined independent rotation speed. The hybrid vehicle according to claim 3,
Required driving force setting means for setting required driving force required for traveling;
When the end of the warm-up operation control is prohibited by the warm-up end prohibiting means, the internal combustion engine is operated independently at the independent rotation speed and power based on the set required driving force is obtained. A hybrid vehicle further comprising drive control means capable of controlling the internal combustion engine and the electric motor.   5. The process according to claim 1, wherein the abnormality diagnosis is a process of determining whether or not there is an abnormality in the cold emission reduction process based on an integrated value of fuel supplied to the internal combustion engine after the internal combustion engine is started. The described hybrid vehicle. The hybrid vehicle according to any one of claims 1 to 5,
Power power input / output connected to the engine shaft and the axle of the internal combustion engine and capable of inputting / outputting power to / from the engine shaft and the axle together with input / output of power and power and exchanging power with the power storage means. A hybrid vehicle further comprising means.   The power drive input / output means is connected to three shafts of a generator motor capable of inputting / outputting power, the axle, the engine shaft of the internal combustion engine, and a rotation shaft of the generator motor, and among these three shafts The hybrid vehicle according to claim 6, further comprising: a three-axis power input / output unit that inputs / outputs power based on power input / output to / from any one of the two shafts. An internal combustion engine capable of outputting traveling power, a purification means including a catalyst for purifying exhaust gas discharged from the internal combustion engine, an electric motor capable of outputting traveling power, and electric power exchangeable with the electric motor And a control parameter of the internal combustion engine is set so that activation of the catalyst is promoted until a predetermined catalyst activation condition is satisfied after the internal combustion engine is started in a predetermined cold state. A control method for a hybrid vehicle comprising a cold engine control means for executing warm-up operation control of the internal combustion engine with cold emission reduction processing,
A hybrid vehicle control method including a step of executing an abnormality diagnosis for determining whether or not the cold emission reduction process is abnormal while prohibiting the end of the warm-up operation control.

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