JP5692008B2 - Hybrid car - Google Patents

Description

  The present invention relates to a hybrid vehicle, and more specifically, a plurality of cylinders in which an exhaust gas purification apparatus having a motor that outputs driving power, a battery that can supply power to the motor, and a catalyst that purifies exhaust gas is attached to an exhaust system. If the engine coolant temperature is lower than the required warm-up temperature for the exhaust gas purifier when the engine is started during the electric running that uses the power from the motor and the motor, the catalyst is warmed up. A hybrid vehicle comprising: control means for controlling to run or charge a battery using power from the engine after performing catalyst warm-up control for making the ignition timing later than the ignition timing after completion of warm-up for promotion About.

  Conventionally, as this type of technology, in order to warm up the catalyst device attached to the exhaust system of the engine, the ignition timing is retarded compared to the normal operation, and the engine is operated during the catalyst warm-up operation. There has been proposed one that corrects the fuel injection amount for each cylinder of the engine so as to suppress the variation in the rotational speed of the crankshaft caused by each combustion (see, for example, Patent Document 1). In this technique, fluctuations in the output torque output from the engine during the catalyst warm-up operation are suppressed by correcting the fuel injection amount for each cylinder.

JP 2008-297933 A

  In general, an engine in a catalyst warm-up operation is retarded in ignition timing, so that the amount of fuel injected into some cylinders of the engine is smaller than the amount of fuel injected into other cylinders. During lean imbalance when the fuel ratio becomes lean, misfire may occur in some cylinders, and unburned fuel may be discharged. It is considered effective to correct the fuel injection amount for each cylinder of the engine so as to suppress the variation in the rotational speed of the crankshaft as in the above-described technique, but when the rotational speed of the crankshaft varies, In many cases, it is already during lean imbalance, and misfires will occur if correction is not performed quickly and properly.

  The main purpose of the hybrid vehicle of the present invention is to achieve both catalyst warm-up and suppression of misfire during lean imbalance.

  The hybrid vehicle of the present invention employs the following means in order to achieve the main object described above.

The hybrid vehicle of the present invention
A motor that outputs power for traveling, a battery that can supply power to the motor, a multi-cylinder engine in which an exhaust purification device having a catalyst that purifies exhaust gas is attached to an exhaust system, and power from the motor In order to promote warming-up of the catalyst when the temperature of the cooling water of the engine is lower than the warming-up temperature required for warming up the catalyst in the exhaust gas purification device when the engine is started during electric running In a hybrid vehicle comprising: control means for performing catalyst warm-up control that makes the ignition timing of the engine slower than the ignition timing after completion of warm-up,
When the engine is started during electric running, the control means is configured such that the temperature of the cooling water of the engine is lower than the required warm-up temperature and the fuel injection amount to some of the cylinders of the engine is other cylinders. Is a lean imbalance when the air-fuel ratio to the engine is in a lean state because the fuel injection amount is smaller than the amount of fuel injected to the engine. It is a means for prohibiting the catalyst warm-up control when the lean imbalance specific start-up state is less than the temperature and lower than the second temperature that is predetermined as the temperature lower than the first temperature.
It is characterized by that.

  In the hybrid vehicle of the present invention, when the engine is started during electric driving, the temperature of the engine coolant is lower than the temperature required for warming up the catalyst and the fuel for some cylinders of the engine Since the injection amount is smaller than the fuel injection amount to the other cylinders, the air-fuel ratio to the engine is in a lean imbalance state where the engine is in a lean state, and the estimated catalyst temperature is determined in advance as the catalyst has been warmed up. When the temperature is equal to or lower than the first temperature and equal to or higher than a second temperature that is predetermined as a temperature lower than the first temperature (lean imbalance specific start-up state), ignition of the engine is performed to promote warm-up of the catalyst. The catalyst warm-up control, which makes the timing later than the ignition timing after completion of warm-up, is prohibited. That is, when the temperature of the engine cooling water is lower than the required warm-up temperature and at the time of lean imbalance, and further when the estimated temperature of the catalyst is lower than the second temperature, misfire prevention by catalyst warm-up control at the time of lean imbalance is prevented. The catalyst warm-up control is executed to give priority to the catalyst warm-up, and when the estimated temperature of the catalyst is lower than the first temperature and equal to or higher than the second temperature, the catalyst warm-up control by the catalyst warm-up control during the lean imbalance is prevented. In order to give priority, the catalyst warm-up control is not executed. This is because when the estimated temperature of the catalyst is equal to or higher than the second temperature, the catalyst is not fully activated, but a certain degree of activation can be expected, and if the engine is running without performing the catalyst warm-up control, the comparison is made. When the estimated catalyst temperature is lower than the second temperature, it is considered that the catalyst warm-up is completed in a short time. Since the degree of activation of the catalyst is low and it takes time to warm up the catalyst, it is based on the fact that the worsening of emission due to further delay of the warming up of the catalyst is more problematic than the worsening of emission due to misfire. Thereby, coexistence with catalyst warm-up and suppression of misfire can be aimed at. Here, in the hybrid vehicle that executes the catalyst warm-up control only when the engine is started for the first time after the system is started, the catalyst warm-up is determined depending on whether or not the engine is first started after the system is started in the lean imbalance specific start state. The hybrid vehicle that determines whether to perform catalyst warm-up control every time the engine is started is in a lean imbalance specific start state every time the engine is started. Whether or not to prohibit the catalyst warm-up control may be determined depending on whether or not.

  In such a hybrid vehicle of the present invention, when the lean imbalance specific start-up state is established, the control means is configured so that the estimated temperature of the catalyst is higher than the second temperature and higher than or equal to the third temperature equal to or lower than the first temperature. To control the engine so that a predetermined power is output in advance. Here, the first temperature ≧ the third temperature> the second temperature. If it carries out like this, an engine can be drive | operated fixedly (steady operation) so that predetermined power may be output from an engine. For this reason, even at the time of lean imbalance, the occurrence of misfire can be suppressed, and the deterioration of emissions can be suppressed.

  Further, in the hybrid vehicle of the present invention, when the estimated temperature of the catalyst is less than a third temperature lower than the first temperature and higher than the second temperature in the lean imbalance specific starting state, It is means for controlling the engine so that a predetermined power determined in advance is output from the engine until the estimated temperature of the catalyst is higher than the third temperature and higher than or equal to the fourth temperature lower than the first temperature. It can also be said. Here, the temperature is first temperature ≧ fourth temperature> third temperature> second temperature. If it carries out like this, an engine can be drive | operated fixedly (steady operation) so that predetermined power may be output from an engine. For this reason, even at the time of lean imbalance, the occurrence of misfire can be suppressed, and the deterioration of emissions can be suppressed.

  The hybrid vehicle of the present invention includes a generator, and a planetary gear mechanism in which three rotating elements are connected to three axes of an output shaft of the engine, a rotating shaft of the generator, and a driving shaft connected to the axle. The motor may be connected to the drive shaft.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 as an embodiment of the present invention. 2 is a configuration diagram showing an outline of the configuration of an engine 22. FIG. 4 is a flowchart showing an example of a catalyst warm-up execution processing routine executed by an engine ECU 24. It is a flowchart which shows an example of the catalyst warm-up execution process routine of a modification. It is a flowchart which shows an example of the catalyst warm-up execution process routine of a modification. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 120 according to a modification. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 220 of a modified example. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 320 of a modified example. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 420 according to a modification.

  Next, the form for implementing this invention is demonstrated using an Example.

  FIG. 1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 as an embodiment of the present invention. As shown in the figure, the hybrid vehicle 20 according to the embodiment has an engine 22, an engine electronic control unit (hereinafter referred to as “engine ECU”) 24 that controls the drive of the engine 22, and a crankshaft 26 of the engine 22 with carriers. A planetary gear 30 having a ring gear connected to a drive shaft 32 connected to the drive wheels 38a and 38b via a differential gear 37, and a rotor connected to the sun gear of the planetary gear 30. Motor MG1, a motor MG2 configured as, for example, a synchronous generator motor and having a rotor connected to drive shaft 32, inverters 41 and 42 for driving motors MG1 and MG2, and switching of inverters 41 and 42 (not shown) By switching the element A motor electronic control unit (hereinafter referred to as “motor ECU”) 44 that drives and controls the motors MG1 and MG2, a system main relay 55, and inverters 41 and 42 exchange power with the motors MG1 and MG2. A high voltage battery 50 configured as a lithium-ion secondary battery having a voltage of 200 V, a battery electronic control unit (hereinafter referred to as “battery ECU”) 52 for managing the high voltage battery 50, each ECU and auxiliary machine 59 Are connected to a power line (hereinafter referred to as “low voltage system power line”) 54b, for example, a low voltage battery 58 configured as a lead storage battery having a rated voltage of 12V, inverters 41 and 42, and a high voltage. From a power line (hereinafter referred to as a “high voltage system power line”) 54 a that connects the battery 50. A DC / DC converter 57 that steps down the power and supplies it to the low voltage system power line 54b, a charger 60 that is connected to an external power source such as a household power source and can charge the high voltage battery 50, and controls the entire vehicle. A hybrid electronic control unit 70.

  The engine 22 is configured as a multi-cylinder internal combustion engine that can output power by using a hydrocarbon-based fuel such as gasoline or light oil, for example. As shown in FIG. The fuel is injected from the fuel injection valve 126, and the intake air and the gasoline are mixed. The mixture is sucked into the fuel chamber through the intake valve 128, and is generated by an electric spark by the spark plug 130. Explosive combustion is performed, and the reciprocating motion of the piston 132 pushed down by the energy is converted into the rotational motion of the crankshaft 26. Exhaust gas from the engine 22 is discharged to the outside air through a purification device 134 having a catalyst (three-way catalyst) that purifies harmful components such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx). The The engine ECU 24 is configured as a microprocessor centered on a CPU (not shown), and includes a ROM, a RAM, an input / output port, and a communication port in addition to the CPU. The engine ECU 24 includes signals from various sensors that detect the state of the engine 22, a crank position from the crank position sensor 140 that detects the rotational position of the crankshaft 26, and a water temperature sensor 142 that detects the temperature of cooling water in the engine 22. The cooling water temperature Tw from the cylinder, the in-cylinder pressure Pin from the pressure sensor 143 installed in the combustion chamber, 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 From the throttle valve position sensor 146 for detecting the position of the throttle valve 124, the air flow meter signal AF from the air flow meter 148 attached to the intake pipe, and the temperature sensor attached to the intake pipe. An intake air temperature from a support 149, an air-fuel ratio AF from an air-fuel ratio sensor 135a, such as oxygen signal from an oxygen sensor 135b is input via the input port. The engine ECU 24 also integrates various control signals for driving the engine 22, such as a drive signal to the fuel injection valve 126, a drive signal to the throttle motor 136 that adjusts the position of the throttle valve 124, and an igniter. The control signal to the ignition coil 138 and the control signal to the variable valve timing mechanism 150 that can change the opening / closing timing of the intake valve 128 are output via the output port. The engine ECU 24 is in communication with the hybrid electronic control unit 70, controls the operation of the engine 22 by a control signal from the hybrid electronic control unit 70, and outputs data related to the operation state of the engine 22 as necessary. . The engine ECU 24 also calculates the rotational speed of the crankshaft 26, that is, the rotational speed Ne of the engine 22 based on the crank position from the crank position sensor 140.

  The motor EUC 40 is configured as a microprocessor centered on a CPU (not shown), and includes a ROM, a RAM, an input / output port, and a communication port in addition to the CPU. Motor ECU 40 detects signals necessary for driving and controlling motors MG1 and MG2, such as signals from rotational position detection sensors 43 and 44 that detect the rotational positions of the rotors of motors MG1 and MG2, and motors detected by current sensors. Phase currents Iv and Iw applied to MG1 and MG2 are input, and a switching control signal to inverters 41 and 42 is output from motor ECU 40. The motor ECU 40 is in communication with the hybrid electronic control unit 70, controls the driving of the motors MG1 and MG2 by a control signal from the hybrid electronic control unit 70, and, if necessary, data on the operating state of the motors MG1 and MG2. Output to the hybrid electronic control unit 70. The motor ECU 40 also calculates the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 based on signals from the rotational position detection sensors 43 and 44.

  The battery ECU 52 is configured as a microprocessor centered on a CPU (not shown), and includes a ROM, a RAM, an input / output port, and a communication port in addition to the CPU. The battery ECU 52 is connected to signals necessary for managing the high voltage battery 50, for example, the battery voltage Vb from the voltage sensor 51 a installed between the terminals of the high voltage battery 50, and the output terminal of the high voltage battery 50. The charging / discharging current Ib from the current sensor 51b attached to the high-voltage power line 54a, the battery temperature Tb from the temperature sensor 51c attached to the high-voltage battery 50, and the like are input. Data regarding the state of the battery 50 is output to the hybrid electronic control unit 70 by communication. Further, the battery ECU 52 calculates a storage ratio SOC that is a ratio of the storage amount to the total capacity (storage capacity) based on the integrated value of the charge / discharge current Ib detected by the current sensor 51b in order to manage the high voltage battery 50. The input / output limits Win and Wout, which are the maximum allowable power that may charge / discharge the high voltage battery 50, are calculated based on the calculated storage ratio SOC and the battery temperature Tb.

  The charger 60 is connected to the high voltage system power line 54a via a relay 62, and an AC / DC converter 66 that converts AC power from an external power source supplied via a power plug 68 into DC power; A DC / DC converter 64 that converts the voltage of the DC power from the AC / DC converter 66 and supplies the converted voltage to the high voltage system power line 54a.

  The hybrid electronic control unit 70 is configured as a microprocessor centered on the CPU 72, and in addition to the CPU 72, a ROM 74 for storing processing programs, a RAM 76 for temporarily storing data, an input / output port and communication not shown. And a port. The hybrid electronic control unit 70 includes a shift signal SP from the shift position sensor 82 that detects a push signal from the power switch 80 and an operation position of the shift lever 81, and an accelerator pedal position sensor 84 that detects the amount of depression of the accelerator pedal 83. Accelerator opening degree Acc from the vehicle, brake pedal position BP from the brake pedal position sensor 86 that detects the depression amount of the brake pedal 85, vehicle speed V from the vehicle speed sensor 88, connection detection that detects connection of the power plug 68 to the external power source A connection detection signal or the like from the sensor 69 is input via the input port. From the hybrid electronic control unit 70, a drive signal to the system main relay 55 and the relay 62, a switching control signal to the DC / DC converter 64 and the AC / DC converter 66, and a DC / DC converter 57 and a DC / DC converter 64. The switching control signal is output through the output port.

  In the hybrid vehicle 20 of the embodiment, when the system is stopped at home or at a preset charging point, when the power plug 68 is connected to an external power source and the connection is detected by the connection detection sensor 69, the system main relay 55 And the relay 62 are turned on, the charger 60 is controlled, and the high voltage battery 50 is charged with electric power from the external power source. When the system is started after charging the high-voltage battery 50, the storage rate SOC of the high-voltage battery 50 is set to a threshold value Shv (for example, 20% or 30%) set to such an extent that the engine 22 can be started. In the state in which the engine 22 is stopped until the vehicle has traveled in the electric travel priority mode that prioritizes the electric travel that travels only with the power from the motor MG2, and after the storage ratio SOC of the high-voltage battery 50 reaches the threshold value Shv The vehicle travels in the hybrid travel priority mode that travels with priority given to the hybrid travel that uses power from the engine 22 with charging and discharging of the high-voltage battery 50. Since the driving control during traveling does not form the core of the present invention, further detailed description is omitted.

  Next, the operation of the hybrid vehicle 20 of the embodiment, particularly the operation when the engine 22 is started during the electric travel in the electric travel priority mode will be described. FIG. 3 is a flowchart showing an example of a catalyst warm-up execution processing routine executed by the engine ECU 24 in order to control the engine 22 based on the necessity of warming up the catalyst of the purification device 134 immediately after the engine 22 is started. . This routine is executed immediately after the engine 22 is started.

  When the catalyst warm-up execution routine is executed, the engine ECU 24 first determines whether or not to perform catalyst warm-up control such as the coolant temperature Tw from the water temperature sensor 142, the predicted catalyst bed temperature Tcat, and the lean imbalance flag Flib. A process of inputting data necessary for the determination is executed (step S100). Here, the predicted catalyst bed temperature Tcat is determined based on the coolant temperature Tw by a routine (not shown), the load of the engine 22 when the engine 22 is operated, the elapsed time after the operation of the engine 22 is stopped, and the like. The temperature of the catalyst in 134 is predicted and the value stored in a predetermined area of the RAM (not shown) of the engine ECU 24 is read out and input from the predetermined area. The lean imbalance flag Fliv is a value when the air-fuel ratio to the engine 22 is lean (lean imbalance) because the fuel injection amount to some cylinders of the engine 22 is smaller than the fuel injection amount to other cylinders. This is a flag that is set to 1 and the value 0 is set when the lean imbalance is canceled. The lean imbalance is determined by determining that the lean imbalance has occurred when the fluctuation amount of the rotation speed Ne of the engine 22 (the fluctuation amount of the rotation fluctuation or the rotational angular velocity) is equal to or greater than a predetermined threshold value. It can be determined that the lean imbalance has not occurred when the value is less than the value. In the embodiment, the lean imbalance is determined. When it is determined that the lean imbalance has occurred, a value 1 is set as the value of the lean imbalance flag Flib in a predetermined area of the RAM (not shown), and it is determined that the lean imbalance has not occurred. In this case, the value 0 is set as the value of the lean imbalance flag Flib in a predetermined area of the RAM (not shown), and the value of the lean imbalance flag Flib is read out from the predetermined area of the RAM.

  When the data is input in this manner, it is determined whether or not the engine 22 is started for the first time after the system is started (step S110). When the engine 22 is not started for the first time after the system is started, it is necessary to execute the catalyst warm-up control. If it is determined that there is not, the routine is terminated, and when the engine 22 is started for the first time after the system is started, the coolant temperature Tw is compared with a threshold value Twref for determining that the catalyst warm-up control needs to be executed (step S120) When the coolant temperature Tw is equal to or higher than the threshold value Twref, it is determined that it is not necessary to execute the catalyst warm-up control, and this routine is terminated. Here, for example, 60 ° C. or 65 ° C. can be used as the threshold value Twref.

  When the engine 22 is started for the first time after the system is started and the coolant temperature Tw is lower than the threshold value Twref, the lean imbalance flag Flib is checked (step S130). When the lean imbalance flag Flib is 0, that is, in the lean imbalance, If not, the catalyst warm-up control is executed until the predicted catalyst bed temperature Tcat reaches the threshold value Tref1 or higher (steps S150 to S170), and the catalyst warm-up control is stopped when the predicted catalyst bed temperature Tcat reaches the threshold value Tref1 or higher. (Step S180), and this routine ends. Here, the catalyst warm-up control is performed by operating the engine 22 at a predetermined idling rotational speed or a slightly higher rotational speed at a slower (retarded) ignition timing than during normal operation. In this case, it is possible to output no torque from the engine 22 or to output a slight torque. The reason for retarding the ignition timing compared to normal operation is to slow down the combustion by retarding the ignition timing, and to increase the energy discharged to the exhaust system as thermal energy out of the combustion energy. , Based on promoting warm-up of the catalyst of the purification device 134. The threshold value Tref1 is predetermined according to the catalyst as the lower limit temperature in the temperature range where the catalyst of the purification device 134 is sufficiently activated or a temperature in the vicinity thereof, and for example, 350 ° C., 400 ° C., 450 ° C., or the like is used. be able to.

  When the lean imbalance flag Flib is determined to be 1 in step S130, it is determined whether or not the predicted catalyst bed temperature Tcat is lower than the threshold value Tref2 (step S140), and when the predicted catalyst bed temperature Tcat is lower than the threshold value Tref2, The catalyst warm-up control is executed until the predicted catalyst bed temperature Tcat reaches the threshold value Tref1 or more (steps S150 to S180), and this routine ends. When the predicted catalyst bed temperature Tcat is equal to or greater than the threshold value Tre2, the catalyst warm-up control is performed. This routine is terminated without executing. That is, when the lean imbalance occurs, even if it is determined that the catalyst warm-up control is necessary based on the coolant temperature Tw of the engine 22, the catalyst warm-up control is prohibited when the predicted catalyst bed temperature Tcat is equal to or higher than the threshold value Tref2. It is. As described above, the catalyst warm-up control is prohibited when the predicted catalyst bed temperature Tcat is equal to or higher than the threshold value Tref2 when the lean imbalance is occurring, although the catalyst is not sufficiently activated but is expected to be activated to some extent. Even if the catalyst warm-up control is not executed, it is considered that the catalyst warm-up is completed in a relatively short time if the engine 22 is operated, and the lean imbalance is caused by the deterioration of the emission due to a slight delay in completing the catalyst warm-up. This is based on the fact that it is considered more necessary to suppress the deterioration of emissions due to misfire caused by performing catalyst warm-up control that sometimes retards the ignition timing. On the other hand, when the estimated catalyst bed temperature Tcat is less than the threshold value Tref2 when the lean imbalance occurs, the catalyst warm-up control is executed because the degree of catalyst activation is low and the catalyst warm-up takes time. This is based on the fact that it is considered more necessary to suppress the deterioration of the emission due to further delay of the catalyst warm-up than the deterioration of the emission due to misfire caused by executing the catalyst warm-up control. The threshold value Tref2 is determined in advance by experiments as a temperature at which the degree of activation of the catalyst can be expected to some extent. For example, when the threshold value Tref1 is 400 ° C. or 450 ° C., 200 ° C. or 250 ° C. can be used. .

  According to the hybrid vehicle 20 of the embodiment described above, the engine 22 is started for the first time after the system is started, the coolant temperature Tw is lower than the threshold value Twref, the lean imbalance occurs, and the predicted catalyst bed temperature Tcat is When the value is equal to or greater than the threshold value Tref2, the catalyst warm-up control is prohibited, and the catalyst warm-up control takes some time compared to the catalyst warm-up control. Deterioration of emissions due to misfire can be suppressed. In other words, the deterioration of emissions as a whole is suppressed by giving priority to suppressing the deterioration of emissions due to misfire caused by performing catalyst warm-up control over the deterioration of emissions due to a slight delay in the completion of catalyst warm-up. Can be suppressed. Of course, when the engine 22 is started for the first time from the start of the system and the coolant temperature Tw is lower than the threshold value Twref and no lean imbalance occurs, or when the engine 22 is started for the first time after the system is started, the coolant temperature Tw Is less than the threshold value Twref, the lean imbalance occurs, and the predicted catalyst bed temperature Tcat is less than the threshold value Tref2, the catalyst warm-up control is executed. Can be suppressed. As a result, it is possible to achieve both warm-up of the catalyst and suppression of misfire.

  In the hybrid vehicle 20 of the embodiment, when the engine 22 is not started for the first time after system startup, the catalyst warm-up control is not executed regardless of the coolant temperature Tw of the engine 22 or the predicted catalyst bed temperature Tcat. Even when the engine 22 is not started for the first time after the system is started, if the coolant temperature Tw of the engine 22 is lower than the threshold value Twref, the catalyst warm-up control may be executed. In this aspect, as in the embodiment, when the lean imbalance occurs, the catalyst warm-up control is executed when the predicted catalyst bed temperature Tcat is lower than the threshold value Tref2, and when the predicted catalyst bed temperature Tcat is equal to or higher than the threshold value Tref2, the catalyst warm-up control is executed. Machine control may be prohibited. Even in this case, it is possible to obtain the same effect as that of the embodiment, that is, the effect that the deterioration of the emission can be suppressed.

  In the hybrid vehicle 20 of the embodiment, when the engine 22 is started for the first time from the start of the system, the coolant temperature Tw is lower than the threshold value Twref, and further, the lean imbalance occurs and the predicted catalyst bed temperature Tcat is equal to or higher than the threshold value Tref2. Although the catalyst warm-up control is prohibited, not only the catalyst warm-up control is prohibited but the power output from the engine 22 may be set to a constant value. In this case, the catalyst warm-up execution process routine of FIG. 4 may be executed instead of the catalyst warm-up execution process routine of FIG. Steps S100 to S180 of the catalyst warm-up execution processing routine of FIG. 4 are the same as steps S100 to S180 of the catalyst warm-up execution processing routine of FIG. In the catalyst warm-up execution processing routine of FIG. 4, when the predicted catalyst bed temperature Tcat is determined to be equal to or higher than the threshold value Tref2 in step S140, the engine 22 is kept in a constant operating state until the predicted catalyst bed temperature Tcat reaches the threshold value Tref4. Output constant control is performed to output constant power (steps S210 to S230), and when the predicted catalyst bed temperature Tcat reaches the threshold Tref4, the output constant control is stopped (step S240), and this routine is terminated. . Here, the fixed operating state is, for example, an operating state in which the engine 22 outputs a relatively low torque at a rotational speed slightly higher than the idling rotational speed. In this modification, the engine 22 is kept in a certain operating state in this way, and the catalyst is warmed up to some extent. By doing this, although it takes a little more time than when performing catalyst warm-up control in which the ignition timing is retarded compared to during normal operation, the catalyst warm-up control is performed during lean imbalance. Deterioration of emissions due to possible misfire can be suppressed. Note that the threshold Tref4 may be a value that is equal to or smaller than the threshold Tref1 and greater than the threshold Tref2. The threshold magnitude relationship is Tref1 ≧ Tref4> Tref2.

  In the modification in which the catalyst warm-up execution processing routine of FIG. 4 described above is executed, the engine 22 is started for the first time after the system is started, the cooling water temperature Tw is lower than the threshold value Twref, and further, the lean imbalance occurs and the catalyst When the predicted bed temperature Tcat is equal to or higher than the threshold Tref2, the constant output control is executed. However, the constant output control may or may not be executed according to the predicted catalyst bed temperature Tcat. In this case, the catalyst warm-up execution process routine of FIG. 5 may be executed instead of the catalyst warm-up execution process routine of FIG. In the catalyst warm-up execution processing routine of FIG. 5, when the predicted catalyst bed temperature Tcat is determined to be equal to or higher than the threshold value Tref2 in step S140, the predicted catalyst bed temperature Tcat is compared with a threshold value Tref3 that is lower than the threshold value Tref1 and higher than the threshold value Tref2. Step S205) When the predicted catalyst bed temperature Tcat is equal to or higher than the threshold Tref3, the routine is terminated without executing the constant output control and the catalyst warm-up control. When the predicted catalyst bed temperature Tcat is lower than the threshold Tref3, the predicted catalyst bed The constant output control is executed until the temperature Tcat reaches the threshold Tref4 (steps S210 to S230). When the predicted catalyst bed temperature Tcat reaches the threshold Tref4, the constant output control is stopped (step S240), and this routine is terminated. To do. In this modified example, since it is further determined whether or not the constant output control is to be executed in accordance with the predicted catalyst bed temperature Tcat, it is possible to further suppress the deterioration of the emission. The threshold magnitude relationship is Tref1 ≧ Tref4> Tref3> Tref2.

  In the hybrid vehicle 20 of the embodiment, the power of the motor MG2 is output to the drive shaft 32. However, the drive shaft 32 is connected to the power of the motor MG2 as illustrated in the hybrid vehicle 120 of the modified example of FIG. Further, it may be connected to an axle (an axle connected to the drive wheels 39a and 39b in FIG. 6) different from an axle (an axle to which the drive wheels 38a and 38b are connected). Further, in the hybrid vehicle 20 of the embodiment, the power of the engine 22 is output to the drive shaft 32 connected to the drive wheels 38a and 38b via the planetary gear 30, but the hybrid vehicle 220 of the modified example of FIG. As illustrated, an inner rotor 232 connected to the crankshaft of the engine 22 and an outer rotor 234 connected to the drive shaft 32 that outputs power to the drive wheels 38a and 38b, and a part of the power of the engine 22 To the drive shaft 32 and a counter-rotor motor 230 that converts the remaining power into electric power.

  In the hybrid vehicle 20 of the embodiment, the power from the engine 22 is output to the drive shaft 32 connected to the drive wheels 38a and 38b via the planetary gear 30, and the power from the motor MG2 is output to the drive shaft 32. However, as illustrated in the hybrid vehicle 320 of the modified example of FIG. 8, the motor MG is attached to the drive shaft 32 connected to the drive wheels 38a and 38b via the transmission 330, and the clutch 329 is attached to the rotation shaft of the motor MG. The power from the engine 22 is output to the drive shaft 32 via the rotating shaft of the motor MG and the transmission 330, and the power from the motor MG is driven to the drive shaft via the transmission 330. It is good also as what outputs to. Alternatively, as illustrated in the hybrid vehicle 420 of the modified example of FIG. 9, the power from the engine 22 is output to the drive shaft 32 connected to the drive wheels 38a and 38b via the transmission 430 and the power from the motor MG. May be output to an axle different from the axle to which the drive wheels 38a, 38b are connected (the axle connected to the wheels 39a, 39b in FIG. 9). That is, any type of hybrid vehicle may be used as long as it is a type of hybrid vehicle that can be electrically driven.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the embodiment, the motor MG2 corresponds to the “motor”, the high voltage battery 50 corresponds to the “battery”, the engine 22 corresponds to the “engine”, and the engine ECU 24 executes the catalyst warm-up execution processing routine of FIG. Corresponds to “control means”.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the column of means for solving the problem. Therefore, the elements of the invention described in the column of means for solving the problems are not limited. That is, the interpretation of the invention described in the column of means for solving the problems should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problems. It is only a specific example.

  As mentioned above, although the form for implementing this invention was demonstrated using the Example, this invention is not limited at all to such an Example, In the range which does not deviate from the summary of this invention, it is with various forms. Of course, it can be implemented.

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

  20, 120, 220, 320, 420 Hybrid vehicle, 22 engine, 24 engine electronic control unit (engine ECU), 26 crankshaft, 30 planetary gear, 32 drive shaft, 37 differential gear, 38a, 38b drive wheel, 39a, 39b Wheel, 40 Motor electronic control unit (motor ECU), 41, 42 Inverter, 43, 44 Rotation position detection sensor, 50 High voltage battery, 51a Voltage sensor, 51b Current sensor, 51c Temperature sensor, 52 Electronic control unit for battery ( Battery ECU), 54a high voltage system power line, 54b low voltage system power line, 55 system main relay, 57 DC / DC converter, 58 low voltage battery, 60 charger, 62 relay, 64 DC / DC converter , 66 AC / DC converter, 68 power plug, 69 connection detection sensor, 70 hybrid electronic control unit (HVECU), 80 power switch, 81 shift lever, 82 shift position sensor, 83 accelerator pedal, 84 accelerator pedal position sensor, 85 Brake pedal, 86 Brake pedal position sensor, 88 Vehicle speed sensor, 122 Air cleaner, 124 Throttle valve, 126 Fuel injection valve, 128 Intake valve, 130 Spark plug, 132 Piston, 134 Purifier, 135a Air-fuel ratio sensor, 135b Oxygen sensor, 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 an air flow meter, 149 temperature sensor, 150 a variable valve timing mechanism, 230 pair-rotor motor, 232 an inner rotor 232 outer rotor, 330, 430 transmission, MG, MG1, MG2 motor.

Claims (3)

A motor that outputs power for traveling, a battery that can supply power to the motor, a multi-cylinder engine in which an exhaust purification device having a catalyst that purifies exhaust gas is attached to an exhaust system, and power from the motor In order to promote warming-up of the catalyst when the temperature of the cooling water of the engine is lower than the warming-up temperature required for warming up the catalyst in the exhaust gas purification device when the engine is started during electric running In a hybrid vehicle comprising: control means for performing catalyst warm-up control that makes the ignition timing of the engine slower than the ignition timing after completion of warm-up,
When the engine is started during electric running, the control means is configured such that the temperature of the cooling water of the engine is lower than the required warm-up temperature and the fuel injection amount to some of the cylinders of the engine is other cylinders. Is a lean imbalance when the air-fuel ratio to the engine is in a lean state because the fuel injection amount is smaller than the amount of fuel injected to the engine. A means for prohibiting the catalyst warm-up control when the lean imbalance specific start-up state is lower than the second temperature and lower than the first temperature.
A hybrid vehicle characterized by that. The hybrid vehicle according to claim 1,
In the lean imbalance specific start-up state, the control means has a predetermined power predetermined from the engine until the estimated temperature of the catalyst reaches a third temperature that is higher than the second temperature and lower than the first temperature. Means for controlling the engine to be output;
A hybrid vehicle characterized by that. The hybrid vehicle according to claim 1,
When the estimated temperature of the catalyst is lower than the first temperature lower than the first temperature and lower than the third temperature in the lean imbalance specific starting state, the control means determines that the estimated temperature of the catalyst is the third temperature. Means for controlling the engine to output a predetermined power that is predetermined from the engine until it reaches a fourth temperature that is higher than or equal to the first temperature.
A hybrid vehicle characterized by that.